JP2009042386A - Electrostatic charge image developing toner, electrostatic charge image developer and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having good low-temperature fixability and good filming resistance on other members. <P>SOLUTION: The electrostatic charge image developing toner has a core particle containing a crystalline resin and a colorant, and a shell layer covering the core particle, wherein pearl necklace type silica is included in the core particle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrostatic image developing toner, an electrostatic image developing developer, and an image forming apparatus.

  In electrophotography, an electrostatic latent image is electrically formed on a photoconductor using a photoconductive substance by various means, and the electrostatic latent image is converted into an electrostatic image developing toner (hereinafter simply referred to as “toner”). The toner image on the photosensitive member is passed through an intermediate transfer member by developing with a developer for developing an electrostatic charge image (hereinafter sometimes referred to simply as “developer”). After the transfer to a transfer medium such as paper, the fixed image is formed through a plurality of steps of fixing the transfer image by heating, pressurization, heat pressurization, solvent vapor, or the like. . The toner remaining on the photoreceptor is cleaned by various methods as necessary, and the plurality of steps are repeated. Such an electrophotographic method has been widely used not only for copying machines but also for printers due to the development of equipment in the information-oriented society and the enhancement of communication networks, and full-colorization has been rapidly progressing.

  In general, in a full-color image forming method, image formation is performed using three colors of magenta (M), cyan (C), yellow (Y), and further four colors of toner including black (K). . As a color reproduction procedure, the transfer process is repeated for each color of C, M, Y, and K, and a full-color image is formed by superimposing toner images composed of a plurality of colors of toner on the transfer target. In the final fixing step, the superimposed toner images are melted and fixed on the transfer target. In the formation of a full-color image by electrophotography, development is performed a plurality of times, and several types of toner images need to be superimposed in the fixing step. Therefore, the charging characteristics, fluidity, fixing characteristics and the like of each color toner are important.

  However, it is difficult to adjust charging characteristics and to develop fluidity and the like only with toner base particles containing a binder resin, a colorant, a release agent, and the like. Therefore, for the purpose of improving charging characteristics, fluidity, etc., toner is manufactured by externally adding or encapsulating inorganic particles or organic particles to toner base particles.

  In general, inorganic particles are used as an external additive for toner. For example, as an improvement technique for improving the powder characteristics and the initial charge rising characteristics, a technique of externally adding nonmagnetic inorganic particles treated with metal alkoxide to toner base particles has been proposed (see Patent Document 1). Furthermore, a method for producing a toner with little change in charging ability under low temperature and low humidity conditions by externally adding titanium to toner base particles in addition to silica having a prescribed charge amount and particle diameter has been proposed (Patent Document 2). reference).

  In addition, by including metatitanic acid hydrophobized as an external additive, it is not affected by external temperature and humidity, has good chargeability, and has excellent fixability and releasability. Has been proposed (see Patent Document 3).

  As described above, a method of improving the charging characteristics and powder characteristics by using inorganic particles as external additives has become common. Among such techniques, it has also been proposed to improve fixing characteristics by encapsulating inorganic particles in toner base particles. For example, it has been proposed to encapsulate hydrophobic silica in the toner, change the viscoelasticity when the toner is melted, control the penetration phenomenon of the toner into the paper, and widen the fixing temperature range (see Patent Document 4). Further, it has been proposed that the inorganic particles are encapsulated in the toner, whereby the charge amount distribution becomes sharp and the toner fluidity, cleaning property, and offset resistance are improved (see Patent Document 5).

  As described above, by externally adding silica-containing inorganic particles to the toner base particles, an improvement in charging characteristics and an effect of toner fluidity are realized mainly for the rise of initial charging and suppression of charging change. Furthermore, it has been proposed to control viscoelasticity by encapsulating inorganic particles in toner base particles, and to change the fixing characteristics and sharpen the charge distribution.

  Under such circumstances, it has been proposed to use a pearl necklace type silica as an external additive for toner base particles to improve cleaning properties (see Patent Document 6). In the toner by the suspension polymerization method, silica particles are inorganic particles bonded in a chain or branched form, and therefore, embedding in polymer toner base particles can be suppressed and high toner fluidity can be maintained.

  On the other hand, energy development has been screamed in recent toner developments due to increasing environmental problems, and low-temperature fixing has become technically important. As a low-temperature fixing method, a method using a crystalline resin has been proposed (see, for example, Patent Documents 7 and 8).

JP-A-2-150858 JP 2006-208493 A JP 2006-235344 A JP 2000-187358 A JP 2006-184297 A Japanese Patent Laid-Open No. 2002-365834 JP 62-129867 A JP-A-5-5056

  The present invention relates to a toner for developing an electrostatic image, a developer for developing an electrostatic image, and an image forming apparatus having good low-temperature fixing properties and filming resistance to other members.

  The present invention relates to a toner for developing an electrostatic image having core particles containing a crystalline resin and a colorant, and a shell layer covering the core particles, wherein the core particles contain pearl necklace type silica. It is.

  In the electrostatic image developing toner, the content of the crystalline resin contained in the toner is preferably 3% by weight or more and 30% by weight or less.

  In the electrostatic charge image developing toner, it is preferable that the Si element content of the toner measured by X-ray photoelectron spectroscopy is 0.01 atm% or more and less than 0.5 atm%.

  In the electrostatic image developing toner, the toner preferably has a glass transition temperature of 45 ° C. or higher and 55 ° C. or lower.

  In the electrostatic image developing toner, the acid value when the toner is dissolved in tetrahydrofuran is preferably 10 mgKOH / g or more and 20 mgKOH / g or less.

  The present invention also provides an electrostatic charge image developing developer comprising the electrostatic charge image developing toner and a carrier.

  The present invention also provides an image carrier, latent image forming means for forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image using a developer to form a toner image. The image forming apparatus includes a developing unit and a transfer unit that transfers the developed toner image to a transfer target, and the developer is the developer for developing an electrostatic image.

  According to the first aspect of the present invention, there is provided an electrostatic charge image developing toner having better low-temperature fixability and filming resistance to other members than when the core particles do not contain pearl necklace type silica. Can be provided.

  According to the second aspect of the present invention, it is possible to provide a toner for developing an electrostatic charge image having better low-temperature fixability and filming resistance than those having a crystalline resin content outside this range. .

  According to claim 3 of the present invention, the toner for developing an electrostatic charge image has better filming resistance than the toner having a Si elemental content measured by X-ray photoelectron spectroscopy outside this range. Can be provided.

  According to the fourth aspect of the present invention, it is possible to provide a toner for developing an electrostatic image having better low-temperature fixability and filming resistance than those having a glass transition temperature outside this range.

  According to claim 5 of the present invention, it is possible to provide a toner for developing an electrostatic charge image with better filming resistance than that having an acid value when the toner is dissolved in tetrahydrofuran, outside this range. .

  According to the sixth aspect of the present invention, there is provided a developer for developing an electrostatic charge image that has better low-temperature fixability and filming resistance than a case where a pearl necklace type silica is not included in the core particle of the toner. can do.

  According to the seventh aspect of the present invention, it is possible to provide an image forming apparatus having better low-temperature fixability and filming resistance than the case where the pearl necklace type silica is not encapsulated in the toner core particles. .

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

<Toner for electrostatic image development>
In the toner for developing an electrostatic charge image according to the exemplary embodiment, the toner base particles have a core-shell structure, the core particles include a crystalline resin and a colorant, and encapsulate a pearl necklace type silica, whereby the toner strength is increased. Improves and shows good filming resistance. Moreover, it is excellent in low-temperature fixability.

  In the exemplary embodiment, it is preferable that the content of the crystalline resin contained in the toner is 3% by weight or more and 30% by weight or less because the toner strength and the low-temperature fixability tend to be more excellent. The content of the crystalline resin is more preferably 5% by weight or more and 10% by weight or less. If the content of the crystalline resin is less than 3% by weight, the low-temperature fixability may be extremely inferior. If it exceeds 30% by weight, the low-temperature fixability is improved, but improvement in filming resistance cannot be expected. In addition, the electrical characteristics may be extremely inferior. Further, when the amount of the crystalline resin is more than 30% by weight, the filming resistance may not be improved even if 10% by weight or more of pearl necklace type silica is blended.

  In this embodiment, when the blending amount of the pearl necklace type silica contained in the toner is 2% by weight or more and 10% by weight or less, it is preferable because the toner strength is satisfied and the filming resistance is improved. The blending amount of the pearl necklace type silica is more preferably 3% by weight or more and 5% by weight or less. When the blending amount of the pearl necklace type silica is less than 2% by weight, the toner strength cannot be satisfied, and the filming resistance may not be improved. Since many particles exist, the filler effect cannot be expected, and the filming resistance may not be improved. Further, the filming resistance tends to be saturated at about 10% by weight.

  In addition, when the content of Si element measured by X-ray photoelectron spectroscopy of the toner is 0.01 atm% or more and less than 0.5 atm%, it is preferable because the toner strength is satisfied and the filming resistance is improved. . The Si element content of the toner measured by X-ray photoelectron spectroscopy is more preferably 0.05 atm% or more and less than 0.1 atm%. When the Si element content is less than 0.01 atm%, the toner strength cannot be satisfied and the filming resistance may not be improved. When the Si element content is 0.5 atm% or more, the toner is inorganic. Since many particles exist, the filler effect cannot be expected, and the filming resistance may not be improved. Further, the filming resistance tends to be saturated at about 0.5 atm%.

  Here, in this embodiment, the Si element content measured by X-ray photoelectron spectroscopy of the toner is measured as follows. The atomic concentration (atm%) of the toner is calculated from the peak intensity of each element measured by X-ray photoelectron spectroscopy using a relative sensitivity factor provided by PHI. This measurement was performed by sputtering the toner surface in the depth direction with an Ar ion beam. After the sputtering treatment with the Ar ion beam, it was confirmed using a transmission electron microscope. The depth was in the range of 0.01 to 0.5 μm. Under these conditions, the content of Si element having a depth of about 0.01 to 0.5 μm from the surface of the toner can be obtained. As described above, in the toner according to the exemplary embodiment, it is preferable that the content of Si element in the toner is the same. Therefore, for example, XPS measurement is performed under the same conditions on a cross section obtained by cutting the toner particles with a microtome or the like. Even when it is carried out, it is preferable that the same content is obtained.

  In this embodiment, when the glass transition temperature (Tg) of the toner by DSC is 45 ° C. or more and 55 ° C. or less, the pearl necklace type silica is easily included in the toner, and the filming resistance is particularly easily improved. Therefore, it is preferable. The glass transition temperature of the toner is more preferably 50 ° C. or higher and 55 ° C. or lower. When the glass transition temperature of the toner is less than 45 ° C., the low-temperature fixability is very excellent, but the fixing temperature on the high temperature side is also lowered, so that the fixing temperature range is narrowed and it is difficult to use the toner practically. . Further, the compatibility between the crystalline resin and the amorphous resin is advanced, and the compatibility between the pearl necklace type silica and the crystalline resin is expected to be lowered. For this reason, the strength of the crystalline resin portion cannot be increased, the toner strength is satisfied, and the effect of improving the filming resistance may not be expected. Further, when the glass transition temperature of the toner exceeds 55 ° C., the cohesive force of the crystalline resin becomes weak with respect to the temperature and becomes equivalent to the amorphous resin. Therefore, the pearl necklace type silica is selective for the crystalline resin. Are not compatible with each other and are not easily contained in the toner. As a result, since the toner strength does not increase, the filming resistance may not be improved.

  In this embodiment, when the toner has an acid value of 10 mgKOH / g or more and 20 mgKOH / g or less when dissolved in tetrahydrofuran (THF), the pearl necklace type silica is easily included in the toner, and is particularly resistant to filming. It is preferable because the property is easily improved. The acid value of the toner is more preferably 12 mgKOH / g or more and 18 mgKOH / g or less. If the acid value of the toner is less than 10 mgKOH / g, the cohesive force of the coagulant is weakened, so it becomes difficult to encapsulate the pearl necklace type silica, and in some cases, it is difficult to produce the toner by the emulsion aggregation method. If it exceeds 20 mgKOH / g, the cohesive force of the binder resin used for the toner is high, but it does not melt or fuse, and it may be difficult to form the toner.

  The pearl necklace type silica will be described below.

  The pearl necklace type silica is a particle in which a plurality of silica spherical particles are bonded, and is preferably a particle in which silica spherical particles of 10 nm to 30 nm are bonded to a length of 80 nm to 120 nm. Silica particles are strongly bonded by covalent bonds, and a novel effect is expected because the properties that are not manifested by silica particles alone are bonded in a pearl necklace shape. For example, the silica particles are connected to improve the strength.

  Pearl necklace type silica is commercially available, and examples thereof include Snowtex UP series (Nissan Chemical), Snowtex PS series (Nissan Chemical), and the like. In addition to these pearl necklace type silicas, inorganic particles such as silica particles, titanium oxide particles, alumina particles, and cerium oxide particles can be blended as external additives.

  Next, the reason why the pearl necklace type silica is likely to be included in the crystalline resin is described below. For example, in the emulsion aggregation method or the like, usually, inorganic particles such as silica are weakly bound to the binder resin and are not easily included in the toner, and the amount of inclusion is reduced. Thus, even if silica is aggregated using an aggregating agent, the amount of silica contained in the toner is small, and a new or more effective function is not exhibited. Even if pearl necklace type silica is used in such a situation, it is difficult to encapsulate the toner in the toner as in the case of conventional inorganic particles, and the contribution or effect of the pearl necklace type silica to the toner characteristics is not manifested. However, it was confirmed that when a pearl necklace type silica and a crystalline resin were used as a binder resin, the pearl necklace type silica was easily included. As a factor, when a low melting crystalline resin and an amorphous resin having a higher melting point are aggregated by, for example, an emulsion aggregation method, the low melting crystalline resin seems to aggregate first. Therefore, when a pearl necklace type silica that is highly compatible with the crystalline resin is blended, the pearl necklace type silica aggregates in the crystalline resin and the crystalline resin having a low melting point melts, so the pearl necklace type silica is included. To do. Thereafter, when the temperature during the aggregation process is further increased, the crystalline resin containing the amorphous resin and the pearl necklace type silica aggregates, and as a result, the toner containing the pearl necklace type silica in the crystalline resin. It becomes a mother particle.

  As described above, when the glass transition temperature by DSC of the toner is 45 ° C. or higher and 55 ° C. or lower, an appropriate amount of the crystalline resin is blended, so that the cohesion is particularly good, and the pearl necklace is contained in the crystalline resin. The toner base particles contain more type silica.

  Further, in this aggregation step, when the acid value of the binder resin used for the production of the toner base particles is 10 mgKOH / g or more and 20 mgKOH / g or less, the pearl necklace type silica is easily included because the aggregation property is improved. Therefore, it is considered that the following effects were manifested.

  Since a low melting crystalline resin having a melting point of 45 ° C. or higher and 55 ° C. or lower is very soft, a toner containing such a crystalline resin usually has a problem in filming resistance. However, since the pearl necklace type silica is included in the crystalline resin portion, the strength of the crystalline resin portion is improved. As a result, it is considered that the strength of the whole toner is improved and the filming property is improved. Furthermore, even if pearl necklace type silica is encapsulated, the resin characteristics of the crystalline resin are hardly impaired, so that it is possible to fix at low temperature and to achieve filming resistance at the same time.

  In the conventional kneading and pulverization method, which is the most common toner production method, it is possible to blend pearl necklace type silica with the binder resin, but when kneading and pulverizing, the silica bonded to the necklace type is also crushed. Therefore, the effect can hardly be expressed. In addition, it is possible to add a pearl necklace type silica to the binder resin in the toner by the suspension polymerization method, and it seems that the toner can be produced by the suspension polymerization method. However, in the toner using the amorphous resin as the binder resin, even if the pearl necklace type silica is used, the silica is not sufficiently encapsulated in the toner, and the strength of the amorphous resin is already present. It does not seem to improve the toner characteristics at all. Further, when a pearl necklace type silica is used in the emulsion aggregation method, the cohesive force of the silica itself is weak and the amount contained in the toner is reduced, so that the effect can hardly be expressed. From the above, there has been no example of improving the toner characteristics using conventional pearl necklace type silica.

  The toner according to the exemplary embodiment is a toner having a low-temperature fixability, but includes a crystalline resin and a colorant, and mainly includes a core particle portion that imparts a low-temperature fix property and a shell portion that covers the core particle. It is a so-called function-separated core-shell toner.

(Core particles)
The core particles included in the toner according to the exemplary embodiment include a binder resin including a crystalline resin such as a crystalline polyester resin and a colorant, and other components as necessary.

  First, the crystalline resin will be described. In the present embodiment, “crystallinity” of “crystalline resin” refers to having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC) of the resin or toner. 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 ° C. or more and 50 ° C. or less when the toner is used.

  Further, the “amorphous resin” used as the binder resin means that when the temperature from the onset point to the peak top of the endothermic peak exceeds 10 ° C. in the differential scanning calorimetry (DSC) of the resin or toner, or clearly It indicates that the resin does not show a significant 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 resin”.

  The crystalline resin is not particularly limited as long as it is a crystalline resin, and specific examples include crystalline polyester resins and crystalline vinyl resins. From the viewpoint of adjusting the melting point within a preferable range, a crystalline polyester resin is preferable. An aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

  Crystalline vinyl resins include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, Undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate, etc. Examples thereof include vinyl resins using long-chain alkyl or alkenyl (meth) acrylic acid esters. In this specification, the description “(meth) acryl” means that both “acryl” and “methacryl” are included.

  On the other hand, the crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In this embodiment, the “acid-derived constituent component” refers to a component before synthesis of the polyester resin. The component part which was an acid component is pointed out, and the "alcohol-derived component" refers to the component part which was an alcohol component before the synthesis of the polyester resin.

  When the polyester resin is not crystalline, that is, amorphous, it tends to be unable to maintain toner blocking resistance and image storage stability while ensuring good low-temperature fixability. In the case of a polymer in which other components are copolymerized with respect to the crystalline polyester main chain, when the other components are 50% by weight or less, this copolymer is also called a crystalline polyester resin.

[Acid-derived components]
The acid-derived constituent component is preferably an aliphatic dicarboxylic acid, and particularly preferably a linear carboxylic acid. For example, succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid Acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc., or lower alkyl esters thereof, Acid anhydrides can be mentioned but are not limited to these. Among the aliphatic dicarboxylic acids, in view of availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable.

  As the acid-derived constituent component, in addition to the above-mentioned aliphatic dicarboxylic acid-derived constituent component, a constituent component such as a dicarboxylic acid-derived constituent component having a double bond, a dicarboxylic acid-derived constituent component having a sulfonic acid group, or the like is included. Is preferred. 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.

  A dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing because the entire resin can be crosslinked using the double bond. Examples of such dicarboxylic acids include, but are not limited to, fumaric acid, maleic 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.

  A dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, if a sulfonic acid group is present when the entire resin is emulsified or suspended in water to produce fine particles, it can be emulsified or suspended without using a surfactant, as will be described later. Examples of the dicarboxylic acid having a sulfonic acid group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt and the like are preferable in terms of cost.

  The content of acid-derived components other than these aliphatic dicarboxylic acid-derived components (dicarboxylic acid-derived component having a double bond and / or dicarboxylic acid-derived component having a sulfonic acid group) in the acid-derived component Is preferably 1 component mol% or more and 20 component mol% or less, more preferably 2 component mol% or more and 10 component mol% or less.

  When the content is less than 1 component mol%, pigment dispersion may not be good, the emulsified particle diameter may be large, and adjustment of the toner diameter by aggregation may be difficult. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered, the melting point is lowered, the image storage stability is deteriorated, or the emulsion particle size is too small to dissolve in water, and no latex is produced. There is a case. In the present specification, “constituent mol%” refers to a percentage when each constituent component (acid-derived constituent component, alcohol-derived constituent component) in the polyester resin is 1 unit (mol).

[Alcohol-derived components]
The alcohol-derived constituent component is preferably an aliphatic diol, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,20-eicosanediol, etc., but are not limited thereto. Among the aliphatic diols, 1,9-nonanediol and 1,10-decanediol are preferable in view of the melting point and resistance of the resin.

  The alcohol-derived constituent component preferably 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 more preferably 90 constituent mol% or more.

  When the content 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 may be deteriorated. On the other hand, examples of other components included as necessary include components such as a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group.

  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. On the other hand, as the diol having a sulfonic acid group, 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, 2-sulfo-1,4-butane Examples include diol sodium salt.

  Alcohol-derived components in the case of adding alcohol-derived components other than these linear aliphatic diol-derived components (diol-derived component having a double bond and / or diol-derived component having a sulfonic acid group) As content in a component, 1 to 20 component mol% is preferable, and 2 to 10 component mol% is more preferable. When the content is less than 1 constituent mol%, pigment dispersion may be poor, the emulsified particle diameter may be large, and adjustment of the toner diameter by aggregation may be difficult. On the other hand, if it exceeds 20 component mol%, the crystallinity of the polyester resin is lowered, the melting point is lowered, the image storage stability is deteriorated, or the emulsion particle size is too small to dissolve in water, and no latex is produced. There is a case.

  The method for producing 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. Examples thereof include direct polycondensation and transesterification. Depending on the type of production. 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 polyester resin can be produced at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower. If necessary, the reaction system is reduced in pressure and reacted while removing water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  Catalysts usable 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; metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium and germanium. A phosphorous acid compound, a phosphoric acid compound, an amine compound, etc., specifically, the following compounds are mentioned.

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

  In addition to the polymerizable monomers described above for the purpose of adjusting the melting point, molecular weight, etc. of the crystalline resin that is the main component of the binder resin in the present embodiment, shorter chain alkyl groups, alkenyl groups, aromatic rings, etc. It is also possible to use compounds having Specific examples include dicarboxylic acids, alkyl dicarboxylic acids such as succinic acid, malonic acid, and oxalic acid, and phthalic acid, isophthalic acid, terephthalic acid, homophthalic acid, 4,4′-bibenzoic acid, 2,6- Examples include aromatic dicarboxylic acids such as naphthalenedicarboxylic acid and 1,4-naphthalenedicarboxylic acid, and nitrogen-containing aromatic dicarboxylic acids such as dipicolinic acid, dinicotinic acid, quinolinic acid, and 2,3-pyrazinedicarboxylic acid. Short chain alkyl diols such as succinic acid, malonic acid, acetone dicarboxylic acid, diglycolic acid, etc. In the case of short chain alkyl vinyl polymerizable monomers, methyl (meth) acrylate, (meth) Short chain alkyls such as ethyl acrylate, propyl (meth) acrylate, butyl (meth) acrylate, alkenyl (meth Acrylic esters, vinyl nitriles such as acrylonitrile and methacrylonitrile, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketones, ethylene, propylene, butadiene, isoprene, etc. Olefins and the like. These polymerizable monomers may be used individually by 1 type, and may use 2 or more types together.

  In the present embodiment, a compound having a hydrophilic polar group can be used as long as it is copolymerizable as a resin for an electrostatic charge image developing toner. As a specific example, when the resin used is a polyester, a dicarboxylic acid compound in which an aromatic ring such as sulfonyl-terephthalic acid sodium salt or 3-sulfonylisophthalic acid sodium salt is directly substituted with a sulfonyl group is used. In the case of a resin, unsaturated aliphatic carboxylic acids such as (meth) acrylic acid and itaconic acid, glycerin mono (meth) acrylate, fatty acid-modified glycidyl (meth) acrylate, zinc mono (meth) acrylate, zinc di (meth) acrylate, Esters of (meth) acrylic acid and alcohols such as 2-hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol (meth) acrylate, sulfonyl groups at any of the ortho, meta, and para positions Have Derivatives of styrene, sulfonyl group-substituted aromatic vinyl such as sulfonyl group-containing vinyl naphthalene.

  In addition, a cross-linking agent can be added to the crystalline resin in the present embodiment, if necessary, for the purpose of preventing gloss unevenness, color unevenness, hot offset, etc. during fixing in a high temperature region. Specific examples of the crosslinking agent include aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene, divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesate / trivinyl, divinyl naphthalenedicarboxylate, Polyvinyl esters of aromatic polyvalent carboxylic acids such as diphenyl biphenyl carboxylate, divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridine dicarboxylate, unsaturated heterocyclic compounds such as pyrrole and thiophene, vinyl pyromumate, Vinyl esters of unsaturated heterocyclic compounds such as vinyl furancarboxylate, vinyl pyrrole-2-carboxylate, vinyl thiophenecarboxylate, butanediol methacrylate, hexanediol acrylate, octanediol methacrylate (Meth) acrylic acid esters of linear polyhydric alcohols such as relate, decanediol acrylate and dodecanediol methacrylate, branching such as neopentylglycol dimethacrylate, 2-hydroxy, 1,3-diacryloxypropane, (Meth) acrylic acid esters of polyhydric alcohols, polyethylene glycol di (meth) acrylate, polypropylene polyethylene glycol di (meth) acrylates, divinyl succinate, divinyl fumarate, vinyl / divinyl maleate, divinyl diglycolate, itaconic acid Vinyl / divinyl, divinyl acetone dicarboxylate, divinyl glutarate, divinyl 3,3′-thiodipropionate, divinyl aconite / trivinyl, divinyl adipate, divinyl pimelate Divinyl suberic, azelaic, divinyl sebacate, divinyl dodecanedioate divinyl, the polyvinyl esters of polycarboxylic acids such as oxalic acid divinyl and the like.

  In particular, when the crystalline resin is polyester, unsaturated polycarboxylic acids such as fumaric acid, maleic acid, itaconic acid, and trans-aconitic acid are copolymerized in the polyester, and then multiple bond portions in the resin are bonded together. Alternatively, a method of crosslinking using another vinyl compound may be used. In this embodiment, these crosslinking agents may be used individually by 1 type, and may be used in combination of 2 or more types.

  As a method of cross-linking with these cross-linking agents, a method of polymerizing and cross-linking with a cross-linking agent at the time of polymerization of the polymerizable monomer may be used, or after the unsaturated portion remains in the resin and the resin is polymerized, or a toner is produced. Thereafter, a method of crosslinking the unsaturated portion by a crosslinking reaction may be used.

  When the resin to be used is polyester, the polymerizable monomer can be polymerized by condensation polymerization. As the polycondensation catalyst, known ones can be used. Specific examples include titanium tetrabutoxide, dibutyltin oxide, germanium dioxide, antimony trioxide, tin acetate, zinc acetate, tin disulfide and the like. Can be mentioned. When the resin to be used is a vinyl resin, the polymerizable monomer can be polymerized by radical polymerization.

  The radical polymerization initiator is not particularly limited as long as it is capable of emulsion polymerization. Specifically, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide , Ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyltetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-butyl hydroperoxide, tert-butyl formate, Peroxides such as tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) carbamate, 2,2 '-Azobisp Bread, 2,2′-dichloro-2,2′-azobispropane, 1,1′-azo (methylethyl) diacetate, 2,2′-azobis (2-amidinopropane) hydrochloride, 2,2 ′ -Azobis (2-amidinopropane) nitrate, 2,2'-azobisisobutane, 2,2'-azobisisobutyramide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2- Methyl methylpropionate, 2,2′-dichloro-2,2′-azobisbutane, 2,2′-azobis-2-methylbutyronitrile, dimethyl 2,2′-azobisisobutyrate, 1,1′-azobis (1 -Sodium methylbutyronitrile-3-sulfonate), 2- (4-methylphenylazo) -2-methylmalonodinitrile, 4,4'-azobis-4-cyanovaleric acid, 3,5-dihy Roxymethylphenylazo-2-methylmalonodinitrile, 2- (4-bromophenylazo) -2-allylmalonodinitrile, 2,2′-azobis-2-methylvaleronitrile, 4,4′-azobis-4 -Dimethyl cyanovalerate, 2,2'-azobis-2, 4-dimethylvaleronitrile, 1,1'-azobiscyclohexanenitrile, 2,2'-azobis-2-propylbutyronitrile, 1,1'- Azobis-1-chlorophenylethane, 1,1′-azobis-1-cyclohexanecarbonitrile, 1,1′-azobis-1-cycloheptanenitrile, 1,1′-azobis-1-phenylethane, 1,1 ′ -Azobiscumene, 4-nitrophenylazobenzyl cyanoacetate ethyl, phenylazodiphenylmethane, phenylazotriphenylmeth Tan, 4-nitrophenylazotriphenylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol) -2,2'-azobisisobutyrate) and the like, 1,4-bis (pentaethylene) -2-tetrazene, 1,4-dimethoxycarbonyl-1,4-diphenyl-2-tetrazene and the like Can be mentioned.

  The polymerization initiator can also be used as an initiator for a crosslinking reaction in the crosslinking step.

  The weight average molecular weight (Mw) of the crystalline resin is preferably in the range of 10,000 to 30,000, more preferably in the range of 20,000 to 30,000. If the Mw is less than 10,000, the image durability may be lowered and the inclusion property may be lowered due to an increase in the acid value. If the Mw is more than 30000, the compatibility of the amorphous resin may be lowered. The number average molecular weight (Mn) of the crystalline resin is preferably 2000 or more, and more preferably 4000 or more. When the number average molecular weight (Mn) is less than 2000, the toner permeates into the surface of a recording medium such as paper at the time of fixing to cause uneven fixing, and the strength against bending resistance of the fixed image decreases, which is not preferable.

(Shell layer)
In the toner according to the exemplary embodiment, the shell layer covering the core particles preferably includes amorphous resin particles mainly for the purpose of imparting filming resistance.

  The amorphous resin used in the toner according to the exemplary embodiment is not particularly limited. Specifically, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, acrylic acid acrylic monomers such as n-propyl, butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc. Methacrylic monomers; Ethylene unsaturated acid monomers such as acrylic acid, methacrylic acid and sodium styrenesulfonate; Vinyl nitriles such as acrylonitrile and methacrylonitrile; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether Kind Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; homopolymers of olefin monomers such as ethylene, propylene and butadiene, copolymers obtained by combining two or more of these monomers, or Mixtures thereof, furthermore, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or mixtures thereof with the vinyl resins, in the presence of these Examples thereof include a graft polymer obtained by polymerizing a vinyl monomer. These resins may be used alone or in combination of two or more. Of these resins, styrene resins and acrylic resins are particularly preferable.

  The weight average molecular weight (Mw) of the amorphous resin is preferably in the range of 10,000 to 50,000, more preferably in the range of 15,000 to 45,000. If Mw is less than 10,000, offset may occur at the time of high-temperature fixing or image strength may deteriorate, and if it exceeds 50,000, low-temperature fixability may be deteriorated or gloss of a fixed image may decrease. . The number average molecular weight (Mn) of the amorphous resin is preferably in the range of 5000 to 40000, and more preferably in the range of 8000 to 35000. If Mn is less than 5000, the strength of the fixed image may be reduced. If it exceeds 40000, the low-temperature fixability may be deteriorated, or the gloss of the fixed image may be reduced.

  The colorant used in the toner of the exemplary embodiment may be a dye or a pigment, but a pigment is preferable from the viewpoint of light resistance and water resistance. Preferred pigments include carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, Quinacridone, benzidine yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 can be used. Magnetic powder can also be used as a colorant. As the magnetic powder, known magnetic materials such as ferromagnetic metals such as cobalt, iron and nickel, alloys of metals such as cobalt, iron, nickel, aluminum, lead, magnesium, zinc and manganese, and oxides can be used.

  These can be used alone or in combination of two or more. The content of these colorants is preferably from 0.1 to 40 parts by weight, more preferably from 1 to 30 parts by weight, based on 100 parts by weight of the binder resin.

  In addition, each color toner such as yellow toner, magenta toner, cyan toner, and black toner can be obtained by appropriately selecting the type of the colorant.

  There is no restriction | limiting in particular as another component, According to the objective, it can select suitably, For example, well-known various additives, such as an inorganic particle, a charge control agent, a mold release agent, etc. are mentioned.

  In addition to the pearl necklace type silica, inorganic particles may be added to the toner of the exemplary embodiment as necessary. As the inorganic particles, silica particles, titanium oxide particles, alumina particles, cerium oxide particles, or known inorganic particles such as those obtained by hydrophobizing the surface thereof can be used alone or in combination of two or more kinds. Silica particles having a refractive index smaller than that of the binder resin are preferable from the viewpoint that transparency such as color developability and OHP permeability is not impaired. Further, the silica particles may be subjected to various surface treatments, and for example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil or the like are preferable.

  By adding these inorganic particles, the viscoelasticity of the toner can be adjusted, and the glossiness of the image and the penetration into the paper can be adjusted. The inorganic particles are preferably contained in an amount of 0.5% to 20% by weight, more preferably 1% to 15% by weight, based on 100 parts by weight of the toner raw material.

  A charge control agent may be added to the toner of the exemplary embodiment as necessary. As the charge control agent, chromium-based azo dyes, iron-based azo dyes, aluminum azo dyes, salicylic acid metal complexes, and the like can be used.

  The toner of this embodiment preferably contains a release agent. By including a release agent, the releasability in the fixing process is improved. In the contact heating type fixing method, the release oil applied to the fixing roll can be reduced or eliminated. Deterioration of roll life and oil streaks can be avoided, and the cost can be reduced.

  Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax・ Petroleum-based wax.

  The melting point of the release agent is preferably 50 ° C. or higher and 120 ° C. or lower, and more preferably below the melting point of the binder resin. If the melting point of the release agent is less than 50 ° C., the change temperature of the release agent is too low, and the blocking resistance may be inferior, or the developability may deteriorate when the temperature in the copying machine increases. On the other hand, when it exceeds 120 ° C., the change temperature of the release agent is too high, and the low-temperature fixability of the crystalline resin may be impaired.

  Moreover, these mold release agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the release agent is preferably 1 part by weight or more and 20 parts by weight or less, more preferably 2 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the toner raw material. If the amount is less than 1 part by weight, the effect of adding the release agent may not be obtained. If the amount exceeds 20 parts by weight, the adverse effect on the chargeability tends to appear, and the toner is easily destroyed inside the developing machine, so that the release is performed. In addition to the effect that the agent or toner resin becomes spent on the carrier and the charge is likely to decrease, for example, when color toner is used, the surface of the image at the time of fixing becomes insufficient. The release agent is likely to stay in the image, and transparency may be deteriorated.

  The volume average particle size of the toner according to the exemplary embodiment is preferably 3.0 μm or more and 7.5 μm or less, more preferably 3.5 μm or more and 6.5 μm or less, and further preferably 3.8 μm or more and 6.2 μm or less. When the volume average particle diameter is smaller than 3.0 μm, the chargeability is not sufficient, and the spread of the charge distribution due to the decrease in fluidity tends to cause fogging on the background or toner spillage from the developing device. When the volume average particle diameter is larger than 7.5 μm, the resolution is lowered, and thus sufficient image quality may not be obtained.

  The volume average particle diameter can be measured, for example, by measuring using a Coulter Multisizer II type (manufactured by Beckman-Coulter) with an aperture diameter of 100 μm. 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 value of the shape factor SF1 of the toner according to the exemplary embodiment is preferably 110 or more and 140 or less, and more preferably 112 or more and 135 or less. If SF1 is less than 110, it is difficult to produce stably, and the yield may decrease and the cost may increase. Also, if SF1 exceeds 140, the transferability is reduced, so that the image quality is lowered, and the transfer efficiency is lowered. Further, the fluidity may be lowered.

The shape factor SF1 can be measured using a Luzex image analyzer (manufactured by Nireco Corporation, FT). An optical microscope image of the toner spread on the slide glass is taken into an image analysis device through a video camera, and SF1 of each of the 50 toner particles can be obtained, and the average value thereof can be calculated. SF1 is calculated by the following equation.
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. ]

<Method for producing toner for developing electrostatic image>
The toner manufacturing method according to this embodiment is preferably a wet granulation method in which at least a resin particle dispersion and a colorant particle dispersion are mixed, and a flocculant is added to grow particles. As specific examples of this wet granulation method, the following emulsion aggregation method is preferably exemplified. Hereinafter, the emulsion aggregation method will be described as an example. A crystalline polyester resin will be described as an example of the crystalline resin.

  The emulsion aggregation method includes an emulsification step of emulsifying a binder resin to form emulsion particles (droplets), an aggregation step of forming an aggregate of the emulsion particles (droplets), and the melting point of the binder resin. And a coalescing step for fusing at the above temperatures and heat coalescence. Alternatively, instead of the aggregation step and the coalescence step, a so-called association step may be performed in which aggregation and coalescence are performed simultaneously by aggregating at a temperature equal to or higher than the melting point of the binder resin.

  In the emulsification step, the emulsified particles (droplets) of the crystalline polyester resin are a mixture of an aqueous medium and a mixed liquid (polymer liquid) containing a sulfonated crystalline polyester resin and, if necessary, a colorant. Is formed by applying a shearing force.

  At that time, by heating to a temperature equal to or higher than the melting point of the crystalline polyester resin, the viscosity of the polymer liquid can be lowered to form emulsified particles. Moreover, a dispersing agent can also be used for stabilization of emulsified particles and thickening of the aqueous medium. Hereinafter, such a dispersion of emulsified particles may be referred to as a “resin particle dispersion”.

  Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, and sodium polyacrylate; sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodium laurate, potassium stearate, and the like. Anionic surfactants; cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; zwitterionic surfactants such as lauryldimethylamine oxide; polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, poly Surfactants such as nonionic surfactants such as oxyethylene alkylamine; tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate Include inorganic compounds such as barium carbonate.

  The amount of the dispersant used is preferably 0.01 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the binder resin of the core particles.

  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 dispersion stabilizer such as a surfactant, or emulsion particles can be formed without using them.

  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 crystalline polyester resin is preferably 0.005 μm or more and 1 μm or less, and more preferably 0.01 μm or more and 0.4 μm or less in terms of the average particle diameter (volume average particle diameter). If it is less than 0.005 μm, it almost dissolves in water, making it difficult to produce particles. If it exceeds 1 μm, it becomes difficult to obtain toner particles having a desired particle size of 3.0 μm to 7.5 μm. There is a case.

  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.

  If necessary, an aqueous dispersion of these colorants can be prepared using a surfactant. Hereinafter, such a colorant dispersion may be referred to as a “colored particle dispersion”. As the surfactant and the dispersing agent used for dispersion, the same dispersing agents that can be used when dispersing the crystalline polyester resin can be used.

  In addition, a colorant can be mixed into the resin before forming the emulsified particles. Examples of the method of mixing the colorant into the resin include melt dispersion using a disperser or the like.

  In the agglomeration step, the obtained emulsified particles are mixed with pearl necklace type silica and heated to a temperature near the melting point of the crystalline polyester resin or a temperature equal to or lower than the Tg of the amorphous resin polymer to agglomerate and agglomerate. Form a collection.

  Formation of the aggregate of the emulsified particles can be performed by making the pH of the emulsion liquid acidic with stirring. The pH is preferably 2 or more and 6 or less, and more preferably 2.5 or more and 5 or less. At this time, it is also effective to use a flocculant.

  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.

  Further, when the aggregated particles have reached a desired particle size, a toner having a configuration in which the surface of the core aggregated particles is coated with an amorphous resin may be prepared by additionally adding amorphous resin particles. In this case, the crystalline resin is difficult to be exposed on the toner surface, which is desirable from the viewpoint of chargeability and developability. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

  In the fusion / unification step, the agglomeration is stopped by increasing the pH of the suspension of the aggregated particles to a range of 3 to 9 under the stirring conditions according to the aggregation step. The aggregated particles are fused by heating at a temperature equal to or higher than the melting point. Further, when coated with the amorphous resin, the amorphous resin is also fused to coat the core particles. The heating time may be as long as fusion is performed, and may be performed for about 0.5 hours to 3 hours. If a longer time is taken, the release agent contained in the aggregated particles is likely to be exposed on the toner surface. Therefore, although it is effective for fixing properties, it is not preferable to heat for a long time because it adversely affects the storage stability of the toner.

  Thereafter, when the temperature is lowered to a temperature lower than the crystallization temperature of a crystalline resin such as a crystalline polyester resin to solidify the particles, the particle shape and surface properties change depending on the temperature lowering rate. For example, when the temperature is lowered at a high speed, the spheroidization and the surface are easily smoothed. On the other hand, when the temperature is slowly lowered, the particle shape becomes indefinite and irregularities are easily generated on the particle surface. Therefore, it is preferable to lower the temperature to a temperature equal to or lower than the crystallization temperature of a crystalline resin such as a crystalline polyester resin at a rate of at least 1 ° C./min, preferably at a rate of 3 ° C./min. The toner base particles having a desired BET specific surface area of 2 to 5 and a shape factor SF1 of 110 to 140 are obtained by lowering the temperature at a rate of 1 ° C./min or more and crystallizing the binder resin. be able to.

  The particles obtained by fusing can be made into toner mother 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 in the washing 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. The toner base particles are preferably adjusted to have a moisture content after drying of 1.5% by weight or less, preferably 1.0% by weight or less.

  In the coalescence step or the association step, a crosslinking reaction may be performed when the crystalline polyester resin is heated to the melting point or higher, or after the coalescence is completed. When the crosslinking reaction is performed, for example, an unsaturated sulfonated crystalline polyester resin obtained by copolymerizing a double bond component is used as the binder resin, and for example, t-butylperoxy-2-ethylhexa is added to this resin. A crosslinking reaction is introduced by causing a radical reaction using a polymerization initiator such as noate.

  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 coalescence or association process, or after the coalescence or association process. In this case, a solution obtained by dissolving a polymerization initiator in an organic solvent may be 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.

  According to the toner manufacturing method described above, the toner particle shape and surface smoothness can be controlled. The particle shape of the toner is preferably close to a sphere. By making it spherical, the non-electrostatic adhesive force is reduced, so that the transferability is improved, and further, the charge amount on the toner surface becomes uniform, and the charge maintenance property is also improved.

  In the toner of this embodiment, an external additive such as a fluidizing agent or an auxiliary agent may be added to the surface of the toner particles. As external additives, known particles such as silica particles, titanium oxide particles, alumina particles, cerium oxide particles, inorganic particles such as carbon black, polymer particles such as polycarbonate, polymethyl methacrylate, and silicone resin whose surfaces have been hydrophobized. Can be used. The particle size of the external additive is preferably 30 nm to 200 nm, and more preferably 30 nm to 180 nm. By reducing the particle size of the toner, non-electrostatic adhesion to the photosensitive member is increased, causing transfer failure and causing transfer unevenness such as a superimposed image. It is preferable to add a large-sized external additive having a secondary particle size of 30 nm to 200 nm to improve transferability. If the volume average primary particle size is smaller than 30 nm, the initial toner fluidity is good, but the non-electrostatic adhesion between the toner and the photoreceptor cannot be sufficiently reduced, resulting in a decrease in transfer efficiency and image quality. Doing so, deterioration of image uniformity, and stress in the developing machine over time causes the particles to be embedded in the toner surface, changing the chargeability and causing problems such as lower copy density and fogging on the background. There is a case. On the other hand, if the volume average primary particle diameter is larger than 200 nm, it may be easily detached from the toner surface and the fluidity may be deteriorated.

<Developer and carrier for electrostatic image development>
The developer of this embodiment contains the electrostatic image developing toner. Examples of the developer of the present embodiment include a one-component developer containing toner and a two-component developer containing toner and carrier, but a two-component developer excellent in charge maintenance and stability is preferable. The carrier is preferably a carrier coated with a resin, and more preferably a carrier coated with a nitrogen-containing resin.

  Examples of the nitrogen-containing resin include acrylic resins including dimethylaminoethyl methacrylate, dimethylacrylamide, acrylonitrile and the like, amino resins including urea, urethane, melamine, guanamine, aniline, amide resin, and urethane resin. These copolymer resins may also be used.

  Two or more of the nitrogen-containing resins may be used in combination as the carrier coating resin. Moreover, you may use combining the said nitrogen containing resin and resin which does not contain nitrogen. The nitrogen-containing resin may be used in the form of particles and dispersed in a resin not containing nitrogen. In particular, a urea resin, a urethane resin, a melamine resin, and an amide resin are preferable because they have high negative chargeability and high resin hardness, and can suppress a decrease in charge amount due to peeling of the coating resin.

In general, the carrier needs to have an appropriate electrical resistance value. For example, an electrical resistance value of about 10 ⁹ Ωcm to 10 ¹⁴ Ωcm is required. For example, when the electrical resistance value is as low as 10 ⁶ Ωcm as in the case of an iron powder carrier, the carrier adheres to the image portion of the photoreceptor due to the charge injection from the sleeve, or the latent image charge escapes through the carrier, and the latent image In some cases, problems such as disturbance of the image or loss of images may occur. On the other hand, if the insulating resin is coated thickly, the electrical resistance value becomes too high and carrier charges are difficult to leak, resulting in an edged image. There may be a problem of an edge effect that the image density of the image becomes very thin. Therefore, it is preferable to disperse the conductive powder in the resin coating layer in order to adjust the resistance of the carrier.

  Specific examples of the conductive powder include metals such as gold, silver and copper, carbon black, semiconductive oxides such as titanium oxide and zinc oxide, titanium oxide, zinc oxide, barium sulfate and aluminum borate. In addition, the surface of a potassium titanate powder or the like covered with tin oxide, carbon black, or metal can be used. Among these, carbon black is preferable from the viewpoint of production stability, cost, and conductivity.

  Examples of the method for forming the resin coating layer on the surface of the carrier core material include an immersion method in which a powder of the carrier core material is immersed in the solution for forming the coating layer, and a solution for forming the coating layer on the surface of the carrier core material. Spraying method for spraying, fluidized bed method for spraying the solution for forming the coating layer in a state where the carrier core material is floated by flowing air, and a kneader for mixing the carrier core material and the coating layer forming solution in a kneader coater to remove the solvent. Examples of the coater method include a powder coating method in which a coating resin is finely divided and mixed in a carrier core material and a kneader coater at a melting point or higher of the coating resin and cooled to form a coating, and the kneader coating method and the powder coating method are particularly preferably used. .

  The average film thickness of the resin coating layer formed by the above method is usually in the range of 0.1 μm to 10 μm, preferably 0.2 μm to 5 μm.

  The core material (carrier core material) used in the electrostatic image developing carrier of the present embodiment is not particularly limited, and is a magnetic metal such as iron, steel, nickel, cobalt, or a magnetic oxide such as ferrite or magnetite. Glass beads and the like, and from the viewpoint of using the magnetic brush method, a magnetic carrier is preferable. The volume average particle size of the carrier core material is generally preferably 10 μm to 100 μm, and more preferably 20 μm to 80 μm.

  The mixing ratio (weight ratio) between the toner of this embodiment and the carrier in the two-component developer is in the range of toner: carrier = 1: 100 or more and 30: 100 or less, and 3: 100 or more and 20: 100. The following range is more preferable.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes an image carrier, latent image forming means for forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image with a developer to form a toner image. A developing unit that forms the toner image, and a transfer unit that transfers the developed toner image to the transfer target. The developer for developing an electrostatic charge image is used as the developer. In addition, the image forming apparatus according to the present embodiment includes means other than those described above, for example, charging means for charging the image holding member, fixing means for fixing the toner image transferred to the surface of the transfer target, and the surface of the image holding member. It may also include a cleaning means for removing the remaining toner.

  An example of the image forming apparatus according to the present embodiment is schematically shown in FIG. The image forming apparatus 1 includes a charging unit 10, an exposure unit 12, an electrophotographic photosensitive member 14 that is an image holding member, a developing unit 16, a transfer unit 18, a cleaning unit 20, and a fixing unit 22.

  In the image forming apparatus 1, the charging unit 10 that is a charging unit that charges the surface of the electrophotographic photosensitive member 14 and the charged electrophotographic photosensitive member 14 are exposed around the electrophotographic photosensitive member 14 according to image information. The exposure unit 12 is a latent image forming unit that forms an electrostatic latent image, the developing unit 16 is a developing unit that develops the electrostatic latent image with toner to form a toner image, and the surface of the electrophotographic photoreceptor 14. A transfer unit 18 that is a transfer unit that transfers the toner image formed on the surface of the transfer target 24, and a cleaning unit 20 that is a cleaning unit that removes toner remaining on the surface of the electrophotographic photosensitive member 14 after transfer. Are arranged in this order. A fixing unit 22 that is a fixing unit that fixes the toner image transferred to the transfer target 24 is arranged on the left side of the transfer unit 18.

  An operation of the image forming apparatus 1 according to the present embodiment will be described. First, the surface of the electrophotographic photosensitive member 14 is uniformly charged by the charging unit 10 (charging process). Next, light is applied to the surface of the electrophotographic photosensitive member 14 by the exposure unit 12, and the charged charges in the irradiated portion are removed, and an electrostatic charge image (electrostatic latent image) is formed according to the image information. (Latent image forming step). Thereafter, the electrostatic charge image is developed by the developing unit 16, and a toner image is formed on the surface of the electrophotographic photosensitive member 14 (developing step). For example, in the case of a digital electrophotographic copying machine using an organic photoconductor as the electrophotographic photoconductor 14 and using a laser beam as the exposure unit 12, the surface of the electrophotographic photoconductor 14 is negatively charged by the charging unit 10. Then, a digital latent image is formed in a dot shape by the laser beam light, and toner is applied to the portion irradiated with the laser beam light by the developing unit 16 to be visualized. In this case, a negative bias is applied to the developing unit 16. Next, a transfer member 24 such as paper is superposed on the toner image at the transfer unit 18, and a charge opposite in polarity to the toner is applied to the transfer member 24 from the back side of the transfer member 24, and the toner image is generated by electrostatic force. Is transferred to the transfer target 24 (transfer process). The transferred toner image is heated and pressed by a fixing member in the fixing unit 22 and is fused and fixed to the transfer target 24 (fixing step). On the other hand, toner remaining on the surface of the electrophotographic photoreceptor 14 without being transferred is removed by the cleaning unit 20 (cleaning step). One cycle is completed in a series of processes from charging to cleaning. In FIG. 1, the toner image is directly transferred to the transfer target 24 such as a sheet by the transfer unit 18, but may be transferred via a transfer member such as an intermediate transfer member.

  Hereinafter, the charging unit, the image carrier, the exposure unit, the developing unit, the transfer unit, the cleaning unit, and the fixing unit in the image forming apparatus 1 of FIG. 1 will be described.

(Charging means)
For example, a charging device such as a corotron as shown in FIG. 1 is used as the charging unit 10 as a charging unit, but a conductive or semiconductive charging roll may be used. A contact charger using a conductive or semiconductive charging roll may apply a direct current to the electrophotographic photosensitive member 14 or may superimpose an alternating current. For example, the charging unit 10 charges the surface of the electrophotographic photosensitive member 14 by generating a discharge in a minute space near the contact portion with the electrophotographic photosensitive member 14. Normally, it is charged to −300V or more and −1000V or less. The conductive or semiconductive charging roll may have a single layer structure or a multiple structure. Further, a mechanism for cleaning the surface of the charging roll may be provided.

(Image carrier)
The image carrier has a function of forming at least a latent image (electrostatic charge image). As the image carrier, an electrophotographic photosensitive member is preferably exemplified. The electrophotographic photoreceptor 14 has a coating film containing an organic photoreceptor or the like on the outer peripheral surface of a cylindrical conductive substrate. The coating film is a substrate in which a subbing layer and a photosensitive layer including a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are formed in this order on the substrate as necessary. is there. The order of stacking the charge generation layer and the charge transport layer may be reversed. These are layered photoreceptors in which a charge generation material and a charge transport material are contained in separate layers (charge generation layer, charge transport layer), but both the charge generation material and the charge transport material are the same. A single-layer type photoreceptor included in the above layer may be used, and a laminated photoreceptor is preferable. Further, an intermediate layer may be provided between the undercoat layer and the photosensitive layer. In addition, other types of photosensitive layers such as an amorphous silicon photosensitive film may be used in addition to the organic photoreceptor.

(Exposure means)
There are no particular limitations on the exposure unit 12 that is an exposure means. For example, an optical device that can expose a light source such as semiconductor laser light, LED light, or liquid crystal shutter light on the surface of the image carrier in a desired image-like manner. Can be mentioned.

(Development means)
The developing unit 16 serving as a developing unit has a function of developing a latent image formed on the image carrier with a developer containing toner to form a toner image. Such a developing device is not particularly limited as long as it has the above-mentioned function, and can be appropriately selected according to the purpose. For example, toner for developing an electrostatic image is used using a brush, a roller, or the like. A known developing device having a function of adhering to the electrophotographic photosensitive member 14 may be used. For the electrophotographic photosensitive member 14, a DC voltage is usually used, but an AC voltage may be superimposed and used.

(Transfer means)
As the transfer unit 18 serving as a transfer unit, for example, a charge having a polarity opposite to that of the toner is applied to the transfer target 24 from the back side of the transfer target 24 as shown in FIG. A transfer roll and a transfer roll pressing device using a conductive roll or a semiconductive roll that transfers directly to the surface of the transferred body 24 via the transferred body 24 can be used. . A direct current may be applied to the transfer roll as a transfer current applied to the image carrier, or an alternating current may be applied in a superimposed manner. The transfer roll can be arbitrarily set depending on the width of the image area to be charged, the shape of the transfer charger, the opening width, the process speed (circumferential speed), and the like. Further, a single layer foam roll or the like is suitably used as a transfer roll for cost reduction. As a transfer method, a method of transferring directly to the transfer target 24 such as paper or a method of transferring to the transfer target 24 via an intermediate transfer member may be used.

  A known intermediate transfer member can be used as the intermediate transfer member. Materials used for the intermediate transfer member include polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene phthalate, PC / polyalkylene terephthalate (PAT) blend material, ethylene tetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend materials, and the like can be mentioned. From the viewpoint of mechanical strength, an intermediate transfer belt using a thermosetting polyimide resin is preferable.

(Cleaning means)
The cleaning unit 20 serving as a cleaning unit may be appropriately selected such as one that employs a blade cleaning method, a brush cleaning method, or a roll cleaning method as long as the toner remaining on the image carrier is cleaned. Among these, it is preferable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber. Among them, it is particularly preferable to use a polyurethane elastic body because of its excellent wear resistance. However, there may be a mode in which the cleaning unit 20 is not used when toner having high transfer efficiency is used.

(Fixing means)
The fixing unit 22 that is a fixing unit (image fixing device) fixes the toner image transferred to the transfer medium 24 by heating, pressing, or heating and pressing, and includes a fixing member.

(Transfer)
Examples of the transfer target (paper) 24 to which the toner image is transferred include plain paper, OHP sheet, and the like used in electrophotographic copying machines, printers, and the like. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer target is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with resin, art paper for printing, etc. Can be preferably used.

  By using the toner of the present embodiment, fixing at a significantly lower temperature is possible than before, and energy consumption and warm-up time in the fixing process can be greatly reduced, and excellent preservation of the formed image is possible. Can also be realized. Further, since the toner has excellent fluidity and transferability, an image with excellent image quality can be formed, and charging can be stabilized. Furthermore, since the transfer efficiency is improved, the residual toner is reduced and the cost can be reduced.

  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.

<Measuring method of various characteristics>
First, a method for measuring physical properties of toners and the like used in Examples and Comparative Examples (excluding the method described above) will be described.

(Measurement method of molecular weight and molecular weight distribution of resin)
The molecular weight and molecular weight distribution of the crystalline polyester resin and the like were measured under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. As the experimental conditions, the experiment was performed using a sample concentration of 0.5 wt%, a flow rate of 0.6 mL / min, a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

(Volume average particle diameter of resin particles, colorant particles, etc.)
Volume average particle diameters of resin particles, colorant particles, and the like were measured with a laser diffraction particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).

(Measuring method of resin, toner melting point, glass transition temperature)
The melting point of the crystalline resin and the glass transition point (Tg) of the amorphous resin are from 25 ° C. using a differential scanning calorimeter (manufactured by Mac Science, DSC3110, thermal analysis system 001) according to ASTM D3418-8. It was determined by measuring up to 150 ° C. under a temperature rising rate of 10 ° C./min. In addition, melting | fusing point was made into the peak temperature of an endothermic peak, and the glass transition point was made into the temperature of the intermediate point in the step-like endothermic change.

(Amount of crystalline resin in toner)
The measurement of the content of the crystalline resin in the toner was performed by determining the heat of fusion of the crystalline resin with a differential scanning calorimeter (DSC: manufactured by Mac Science, DSC3110, thermal analysis system 001). Specifically, first, a calibration curve of endothermic amount-crystalline resin content (% by mass) is prepared by blending a known amount of a crystalline resin and an amorphous resin and performing DSC measurement. Next, the toner sample subjected to annealing treatment at 50 ° C. for 24 hours was measured, and the content of the crystalline resin in each toner was determined from the result and the calibration curve. The DSC measurement conditions were 20 ° C. to 150 ° C. with a temperature increase rate of 10 ° C./min.

(Toner acid value)
The acid value (AV) of the toner was measured as follows. The basic operation conforms to JIS K-0070-1992. As the sample, a THF-insoluble component of the toner was previously used after being removed, or a soluble component extracted with a THF solvent by a Soxhlet extractor obtained by the above-described measurement of the THF-insoluble component was used. 1.5 g of the pulverized sample was precisely weighed, placed in a 300 mL beaker, and 100 mL of a toluene / ethanol (4/1) mixture was added and dissolved. Potentiometric titration was performed with an ethanol solution of 0.1 mol / L KOH using an automatic titrator GT-100 (manufactured by Dia Instruments). The amount of KOH solution used at this time is A (mL), and a blank is measured at the same time. The amount of KOH solution used at this time is B (mL). From these values, the acid value was calculated by the following formula (1). In the formula (1), w is a precisely weighed sample amount, and f is a factor of KOH.
Acid value (mgKOH / g) = {(A−B) × f × 5.61} / w Formula (1)

(Surface composition analysis by ESCA (X-ray photoelectron spectroscopy))
The ESCA apparatus and measurement conditions in this example are as follows.
-Equipment used: 1600S type X-ray photoelectron spectrometer manufactured by PHI (Physical Electronics Industries, Inc.)-Measurement conditions: X-ray source MgKα (400 W)
-Spectral region: 800 μm in diameter

<Synthesis of each resin>
(Crystalline resin)
In a heat-dried three-necked flask, 497 parts by weight of ethylene glycol, 23.7 parts by weight of sodium dimethyl 5-sulfoisophthalate, 22.8 parts by weight of dimethyl fumarate, 857 parts by weight of dimethyl sebacate, and dibutyl as a catalyst After adding 0.4 part by weight of tin oxide, the air in the container was made inert with nitrogen gas by a depressurization operation, and stirring was performed at 180 rpm with mechanical stirring for 5 hours. Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled, the reaction was stopped, and 985 parts by weight of crystalline polyester resin (1) was synthesized. In the molecular weight measurement (polystyrene conversion) by gel permeation chromatography, the obtained crystalline polyester resin (1) had a weight average molecular weight (Mw) of 8,500 and a number average molecular weight (Mn) of 3,700. The resin acid value was 10 mgKOH / g.

  Further, when the melting point (Tm) of the crystalline polyester resin (1) was measured by a differential scanning calorimeter (DSC) by the above-described measuring method, it had a clear peak and the peak top temperature was 72 ° C. Met. The content ratio of the copolymer component 5-sulfoisophthalic acid component, fumaric acid component and sebacic acid component, measured and calculated from the NMR spectrum of the resin, was 2: 5: 93, respectively.

(Amorphous resin (1))
In a heat-dried two-necked flask, 200 parts by weight of dimethyl terephthalate, 85 parts by weight of 1,3-butanediol, and 0.3 parts by weight of dibutyltin oxide as a catalyst were placed, and the inside of the container was then subjected to reduced pressure operation. The air was made an inert atmosphere with nitrogen gas, and stirred at 180 rpm for 5 hours by mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled, the reaction was stopped, and amorphous polyester resin (1) (derived from aromatic dicarboxylic acid) Amorphous polyester resin comprising an acid-derived constituent component having a constituent content of 100 constituent% and an alcohol-derived constituent component having an aliphatic diol-derived constituent component content of 100 constituent mole%) 240 parts by weight Was synthesized.

  The weight average molecular weight (Mw) of the obtained amorphous polyester resin (1) was 9500 and the number average molecular weight (Mn) was 4200 by molecular weight measurement (polystyrene conversion) by gel permeation chromatography. Further, when the DSC spectrum of the amorphous polyester resin (1) was measured using the above-mentioned differential scanning calorimeter (DSC), no clear peak was shown, and a stepwise change in the endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 55 ° C. The resin acid value was 18 mgKOH / g.

(Amorphous resin (2))
In producing the amorphous resin (1), 220 parts by weight instead of 200 parts by weight of dimethyl terephthalate, and 80 parts by weight instead of 85 parts by weight of 1,3-butanediol were obtained. ) Was produced. The amorphous resin (2) had a weight average molecular weight (Mw) of 9000 and a number average molecular weight (Mn) of 4000. Further, when the DSC spectrum of the amorphous polyester resin (2) was measured using the above-mentioned differential scanning calorimeter (DSC), no clear peak was shown, and a step-like endothermic change was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 56 ° C. The resin acid value was 22 mgKOH / g.

(Amorphous resin (3))
In producing the amorphous resin (1), 160 parts by weight instead of 200 parts by weight of dimethyl terephthalate, 110 parts by weight instead of 85 parts by weight of 1,3-butanediol, and the amorphous polyester resin (3 ) Was produced. The amorphous resin (3) had a weight average molecular weight (Mw) of 10,000 and a number average molecular weight (Mn) of 5,000. Moreover, when the DSC spectrum of the amorphous polyester resin (3) was measured using the above-mentioned differential scanning calorimeter (DSC), no clear peak was shown, and a stepwise change in the endothermic amount was observed. The glass transition temperature at the midpoint of the stepwise endothermic change was 56 ° C. The resin acid value was 11 mgKOH / g.

<Preparation of each dispersion>
(Crystalline resin dispersion)
Prepare 160 parts by weight of crystalline resin, 233 parts by weight of ethyl acetate, and 0.1 parts by weight of aqueous sodium hydroxide (0.3N), put them in a 500 mL separable flask and heat at 70 ° C., A resin mixture was prepared by stirring with a three-one motor (manufactured by Shinto Kagaku Co., Ltd.). While further stirring this resin mixture, 373 parts by weight of ion-exchanged water was gradually added, phase inversion emulsification was carried out, and the solvent was removed to obtain a crystalline resin dispersion (solid content concentration: 30% by weight).

(Amorphous resin dispersion)
160 parts by weight of amorphous resin (1), 233 parts by weight of ethyl acetate, and 0.1 part by weight of aqueous sodium hydroxide solution (0.3N) were prepared and placed in a 500 mL separable flask. The mixture was heated at 0 ° C. and stirred with a three-one motor (Shinto Kagaku Co., Ltd.) to prepare a resin mixture. While further stirring this resin mixture, 373 parts by weight of ion-exchanged water is gradually added, phase-inversion emulsification and solvent removal are performed to obtain an amorphous resin dispersion (1) (solid content concentration: 30% by weight). Obtained.

  In the same manner, an amorphous resin dispersion (2) (solid content concentration: 30% by weight) was obtained using the amorphous resin (2). Further, an amorphous resin dispersion (3) (solid content concentration: 30% by weight) was obtained using the amorphous resin (3).

(Release agent dispersion)
Paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point: 75 ° C.) 50 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 0.5 parts by weight Ion-exchanged water 200 Part by weight or more is mixed, heated to 95 ° C., dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax T50), and then dispersed by a Manton Gorin high-pressure homogenizer (Gorin), so that the volume average particle size is 0. A release agent dispersion liquid (solid content concentration: 20% by weight) obtained by dispersing a release agent of .23 μm was prepared.

(Colorant dispersion)
Cyan pigment (Dai-Ni Seika Co., Ltd., CI Pigment Blue 15: 3 (copper phthalocyanine)) 1000 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 15 parts by weight Ion-exchanged water 9000 Part by weight or more is mixed, dissolved, and dispersed for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse a colorant (cyan pigment). A liquid was prepared. The volume average particle size of the colorant (cyan pigment) in the colorant dispersion was 0.16 μm, and the solid content concentration was 23% by weight.

<Manufacture of carriers>
(Carrier (1))
Ferrite particles (volume average particle size: 35 μm, GSDv: 1.20) 100 parts by weight Toluene 14 parts by weight Perfluoroacrylate copolymer (critical surface tension 24 dyn / cm) 1.6 parts by weight Carbon black (trade name: VXC- 72, manufactured by Cabot Corporation, volume resistivity: 100 Ωcm or less) 0.12 parts by weight Cross-linked melamine resin particles (volume average particle size: 0.3 μm, toluene insoluble) 0.3 parts by weight

  First, carbon black was diluted in toluene and added to a perfluoroacrylate copolymer and dispersed with a sand mill. Next, the above components other than the ferrite particles were dispersed therein with a stirrer for 10 minutes to prepare a coating layer forming solution. Next, this coating layer forming liquid and ferrite particles are put into a vacuum degassing type kneader and stirred for 30 minutes at a temperature of 60 ° C., and then the pressure is reduced to distill off toluene to form a resin coating layer to form a carrier (1) Got.

<Example 1>
(Manufacture of toner (1))
Crystalline resin dispersion 125 parts by weight Amorphous resin dispersion (1) 325 parts by weight Colorant dispersion 21.74 parts by weight Release agent dispersion 50 parts by weight Pearl necklace type silica (Snowtex UP (Nissan Chemical)) 20% by weight, particles in which spherical silica particles having an average particle size of 60 nm are covalently bonded to an average length of 400 nm) 20 parts by weight Nonionic surfactant (IGEPAL CA897) 1.40 parts by weight The mixture was placed in a stainless steel container and dispersed and mixed for 10 minutes while applying a shearing force at 4000 rpm with a homogenizer (manufactured by IKA, Ultra Lalux T50). Next, 1.75 parts by weight of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was gradually added dropwise, and the homogenizer was rotated at 5000 rpm for 15 minutes and mixed to obtain a raw material dispersion.

  Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 42 ° C. At this time, the pH of the raw material dispersion was controlled in the range of 2.2 to 3.5 with 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The agglomerated particles were formed by maintaining the above pH range for about 2 hours. At this time, the volume average particle diameter of the aggregated particles was 5.4 μm.

  Next, 100 parts by weight of the amorphous resin dispersion (1) was additionally added, and the resin particles of the amorphous resin (1) were adhered to the surface of the aggregated particles. The temperature was further raised to 44 ° C., and aggregated particles were prepared while confirming the size and form of the particles with an optical microscope and Coulter Multisizer II type. Thereafter, the pH was raised to 8.0 in order to fuse the aggregated particles, and then the temperature was raised to 95 ° C. After confirming that the aggregated particles were fused with an optical microscope, the pH was lowered to 6.0 while maintaining the temperature at 95 ° C., and the heating was stopped after 1 hour, followed by cooling at a temperature lowering rate of 1.0 ° C./min. Thereafter, the mixture was sieved with a 20 μm mesh, washed repeatedly with water, and then dried with a vacuum dryer to obtain toner particles (1). The obtained toner particles (1) had a volume average particle diameter of 6.2 μm and a GSDp-under of 1.20.

  To 100 parts by weight of the toner particles, 1.0% by weight of silica particles having a volume average primary particle diameter of 40 nm (Nippon Aerosil Co., Ltd., hydrophobic silica: RX50) subjected to surface hydrophobization treatment and metatitanium as an external additive Addition of 1.0% by weight of metatitanic acid compound particles having a volume average primary particle size of 20 nm, which is a reaction product obtained by treating 40 parts by weight of isobutyltrimethoxysilane and 10 parts by weight of trifluoropropyltrimethoxysilane to 100 parts by weight of acid And mixed for 5 minutes with a Henschel mixer. Further, the toner (1) was obtained by passing through an ultrasonic vibration sieve (Dalton).

(Development of developer)
36 parts by weight of the obtained toner (1) and 414 parts by weight of the carrier (1) were put in a 2 liter V blender, stirred for 20 minutes, and then sieved at 212 μm to prepare a developer (1).

  When the cross section of the particles cut with a microtome was analyzed by SEM (scanning electron microscope S-4800, manufactured by Hitachi High-Technologies Corporation), silica spherical particles having an average particle diameter of 60 nm were covalently bonded to the toner base particles to an average length of 400 nm It was confirmed that the pearl necklace type silica was included.

(Various toner evaluations)
[Evaluation of filming resistance]
The developer (1) thus obtained was charged in a four-tandem DocuCentreColor500 (Fuji Xerox Co., Ltd.) developer and allowed to stand in an environment of 28 ° C./85% RH for 24 hours. After that, it is put in a DocuCentreColor500 remodeling machine (which can be adjusted so that transfer current can be turned on / off), and a halftone image with a toner loading of 0.1 mg / cm ^{2 in} the above environment is displayed on the photoconductor. The image was formed for 5000 sheets while the transfer current was set to Off (transfer was not performed). The results are shown in Table 1.

Further, the surface of the photoreceptor was visually confirmed every 500 sheets, and filming on the surface of the photoreceptor was evaluated according to the following criteria.
◎: Filming up to 5000 sheets is not recognized. ○: Filming up to 5000 sheets is difficult to confirm visually, but there is no practical problem. △: Filming is recognized slightly on 5000 sheets, but practically problematic. No ×: Filming is recognized before 5000 sheets, which is unacceptable

[Evaluation of fixability]
The obtained developer (1) was filled in a developing unit of DocuCentreColor 500 from which the fixing device was removed, and an unfixed image was collected. The image condition was a solid image of 40 mm × 50 mm, the toner loading was 0.50 mg / cm ² , and the recording paper was mirror-coated platinum paper (basis weight: 127 gsm). Subsequently, the fixing device of DocuCentreColor500 (manufactured by Fuji Xerox Co., Ltd.) was modified so that the fixing temperature was variable, and the fixing property of the image was evaluated while gradually increasing the fixing temperature from 90 ° C. to 140 ° C. Note that the fixing property is that the fixed image is bent at a fixing temperature at which the maximum width of an image defect portion of the bent portion is 0.3 mm or less after the fixed image is bent for 10 seconds using a weight of a load (60 sN / m ² ) and returned. It was temperature. The evaluation result of the low-temperature fixing was determined based on 120 ° C., which is called a low-temperature fixing temperature.
○: Low-temperature fixing temperature is 120 ° C or lower ×: Low-temperature fixing temperature is higher than 120 ° C

<Example 2>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 417 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 33 parts by weight instead of 12 parts by weight. A toner (2) was obtained in the same manner as in Example 1 except that the amount of the toner was changed. The volume average particle diameter of the toner (2) was 5.9 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 3>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 283 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 167 parts by weight instead of 125 parts by weight. Toner (3) was obtained in the same manner as in Example 1, except that The volume average particle size of the toner (3) was 6.0 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 4>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 283 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 167 parts by weight instead of 125 parts by weight. In addition, a toner (4) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was 100 parts by weight instead of 20 parts by weight. The volume average particle diameter of the toner (4) was 5.8 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 5>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 417 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 33 parts by weight instead of 125 parts by weight. In addition, a toner (5) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was 100 parts by weight instead of 20 parts by weight. The volume average particle diameter of the toner (5) is 5.5 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 6>
In the production of the toner of Example 1, the addition amount of the amorphous resin dispersion (1) is 233 parts by weight instead of 325 parts by weight, and the addition amount of the crystalline resin dispersion is 217 parts by weight instead of 125 parts by weight. In addition, a toner (6) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was 125 parts by weight instead of 20 parts by weight. The volume average particle diameter of the toner (6) is 6.1 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 7>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 417 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 33 parts by weight instead of 125 parts by weight. In addition, a toner (7) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was 15 parts by weight instead of 20 parts by weight. The volume average particle diameter of the toner (7) is 5.8 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 8>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 433 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 17 parts by weight instead of 125 parts by weight. In addition, a toner (8) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was changed to 110 parts by weight instead of 20 parts by weight. The volume average particle size of the toner (8) is 6.2 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 9>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 467 parts by weight instead of 325 parts by weight, and the amount of the crystalline resin dispersion added was 17 parts by weight instead of 125 parts by weight. In addition, a toner (9) was obtained in the same manner as in Example 1 except that the addition amount of pearl necklace type silica was changed to 60 parts by weight instead of 20 parts by weight. The volume average particle diameter of the toner (9) is 6.1 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 10>
A toner (10) was obtained in the same manner as in Example 1 except that the amorphous resin dispersion (2) was used instead of the amorphous resin dispersion (1) in the production of the toner of Example 1. The volume average particle diameter of the toner (10) is 6.7 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Example 11>
A toner (11) was obtained in the same manner as in Example 1 except that the amorphous resin dispersion (3) was used instead of the amorphous resin dispersion (1) in the production of the toner of Example 1. The volume average particle diameter of the toner (11) was 5.2 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 1>
In the production of the toner of Example 1, a toner (12) was obtained according to Example 1 except that no pearl necklace type silica was used. The volume average particle diameter of the toner (12) was 5.9 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Comparative example 2>
In the production of the toner of Example 1, the amount of the amorphous resin dispersion (1) added was 450 parts by weight instead of 325 parts by weight, and a toner (13) was obtained without using a crystalline resin. The volume average particle diameter of the toner (13) is 6.1 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 3>
Toner (14) was obtained in the same manner as in Example 1 except that 20 parts by weight of spherical silica (Nissan Chemical, Snowtex OL) was used in place of the pearl necklace type silica. The volume average particle size of the toner (14) was 6.0 μm. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

  From the results shown in Table 1, in Examples 1 to 11, the low-temperature fixability and the filming resistance were good. Further, when the amount of the crystalline resin was blended by 3% by weight or more, it was confirmed that the low-temperature fixing property was better, and the low-temperature fixing property of Example 8 which was less than 3% by weight was slightly inferior. In Example 6, since the amount of the crystalline resin blended in the toner base particles was too large, the filming characteristics were slightly inferior even when the amount of pearl necklace type silica was increased. For this reason, it is considered that the amount of the crystalline resin is preferably 30% by weight or less in order to obtain a filming characteristic having no problem on the developing machine. When Example 2 and Example 7 are compared, the amount of pearl necklace type silica, that is, the Si element content measured by X-ray photoelectron spectroscopy is slightly different, but Example 7 has a slightly worse filming characteristic. This confirms that pearl necklace type silica is effective as a means for improving the filming characteristics, and the blending amount is 2% by weight or more, that is, the Si element content measured by X-ray photoelectron spectroscopy is high. It seems that 0.01 atm% or more is preferable. In Examples 3 and 4, the toner DSC Tg was 45 ° C. or lower. Therefore, it seems that the inclusion of the pearl necklace type silica in the crystalline resin is slightly insufficient, and as a result, the filming characteristics are slightly deteriorated.

1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 10 charging part, 12 exposure part, 14 electrophotographic photosensitive member, 16 developing part, 18 transfer part, 20 cleaning part, 22 fixing part, 24 to-be-transferred body.

Claims (7)

A core particle containing a crystalline resin and a colorant, and a shell layer covering the core particle;
A toner for developing an electrostatic charge image, wherein the core particles contain a pearl necklace type silica.   2. The toner for developing an electrostatic charge image according to claim 1, wherein the content of the crystalline resin contained in the toner is 3% by weight or more and 30% by weight or less.   3. The toner for developing an electrostatic charge image according to claim 1, wherein the content of the Si element measured by X-ray photoelectron spectroscopy of the toner is 0.01 atm% or more and less than 0.5 atm%. .   4. The electrostatic charge image developing toner according to claim 1, wherein the toner has a glass transition temperature of 45 ° C. or more and 55 ° C. or less. 5.   5. The electrostatic image developing toner according to claim 1, wherein an acid value when the toner is dissolved in tetrahydrofuran is 10 mgKOH / g or more and 20 mgKOH / g or less. 6.   An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to claim 1 and a carrier. An image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, a developing unit that develops the electrostatic latent image using a developer to form a toner image, and the development A transfer means for transferring the toner image thus transferred to a transfer medium,
The image forming apparatus according to claim 6, wherein the developer is a developer for developing an electrostatic image according to claim 6.

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