JP2008015023A - Electrostatic latent image developing toner, method for producing electrostatic latent image developing toner, electrostatic latent image developer, image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic latent image developing toner having excellent low temperature fixability and electrostatic charging properties under a high temperature-high humidity environment, to provide a method for producing an electrostatic latent image developing toner, to provide an electrostatic latent image developer, to provide an image forming method, and to provide an image forming apparatus. <P>SOLUTION: The electrostatic latent image developing toner comprises: a binder resin; a coloring agent; a mold releasing agent; and a styrene copolymer. The styrene copolymer, having weight average molecular weight (Mw) of 70,000 to 30,000, and also, acid value (AV) of 70 to 220 mgKOH/g is contained <3 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic latent image used for developing an electrostatic latent image formed in an electrophotographic process or the like, a method for producing the toner for developing an electrostatic latent image, and the toner for developing an electrostatic latent image. And an image forming method using the electrostatic latent image developing toner, and an image forming apparatus using the electrostatic latent image developing toner.

  Many methods are known as electrophotographic methods. In general, an exposure process for forming an electrical latent image using various means on a photosensitive layer using a photoconductive material, and a toner using toner. A process of developing the image, a process of transferring the toner image to a recording material (recording medium) such as paper, a process of fixing the toner image to the recording material by heating, pressure, thermal pressure, solvent vapor, or the like; It consists of basic processes such as a process of removing the remaining toner.

  As a means for fusing and fixing the toner to the recording medium, a pressure fixing method for fixing the toner to the recording medium by applying pressure to the recording medium with a pressure roll at room temperature, and a toner by applying heat to the recording medium with a heating roll Contact fixing method such as a heated roll fixing method that fixes toner onto a recording medium, an oven fixing method that fixes toner on a recording medium by applying heat to the recording medium by oven heating, a flash fixing method using a xenon lamp, etc. Examples thereof include an electromagnetic wave fixing method using waves and a non-contact fixing method such as a solvent fixing method in which a toner is fixed to a recording medium by using a solvent. Among these fixing methods, the hot roll fixing method used for the heating roll is most commonly used.

  In recent years, due to technological advances in the electrophotographic field, such electrophotographic processes have been used not only for copiers and printers, but also for printing applications. Even in an environment other than the office environment (for example, under high temperature and high humidity), it is increasingly demanded that the copied material has the same high image quality and hue as the printed material. Furthermore, in recent years, due to consideration for the global environment, office equipment has also been required to save energy, and in the electrophotographic process, reduction of power consumption in the fixing process with the highest power consumption has become a major issue.

  One means for realizing energy saving in such an electrophotographic process is to lower the toner fixing temperature. Furthermore, the toner fixing temperature can be lowered by waiting for the fixing temperature on the surface of the fixing member such as a fixing roll after turning on the power, shortening the so-called warm-up time, extending the life of the fixing member, and fixing latitude. It is possible to further speed up the machine by expanding the machine.

  As a method for lowering the fixing temperature of toner, a technique for lowering the glass transition point of a binder resin for toner is generally performed. However, if the glass transition point is too low, powder (toner) is likely to aggregate in the developing machine and the toner cartridge, or the preservability of the fixed image on the document is deteriorated. Further, in the method of lowering the fixing temperature by reducing the softening temperature of the resin by reducing the molecular weight of the binder resin, the hot offset resistance is deteriorated.

  For the purpose of achieving both blocking prevention, image storage stability, and low-temperature fixability, a method of using a crystalline resin as a binder resin constituting a toner has been known for a long time. However, the crystalline resin is difficult to pulverize by the kneading pulverization method and has a low yield, so that there is a problem that the practicality is poor from the viewpoint of manufacturability.

  For this reason, instead of using a crystalline resin alone as a binder resin, a method of using a crystalline resin and an amorphous resin in combination has been proposed (see, for example, Patent Document 1 and Patent Document 2). By increasing the mixing ratio of the amorphous resin, pulverization is facilitated and the burden on toner production can be reduced. However, in the technique of Patent Document 1, sufficient low-temperature fixability cannot be obtained because the melting point of the crystalline resin is as high as 130 to 200 ° C. In the technique of Patent Document 2, since the amorphous resin portion in the toner becomes bulk, melting of the entire toner is governed by the softening temperature of the amorphous resin, and it is difficult to realize low-temperature fixing. Moreover, if the mixing ratio of the crystalline resin is increased, the manufacturing problem will be resurfaced.

There has also been proposed a technique for obtaining low-temperature fixing by mixing a low-melting crystalline resin and an amorphous resin and controlling the degree of compatibilization between the two (for example, see Patent Document 3). However, if only a combination of an amorphous resin and a crystalline resin is used as the binder resin, the dispersibility of the crystalline resin / release agent in the toner particles and the compatibility of the release agent with the amorphous resin Therefore, the crystalline resin and the release agent are exposed on the toner surface, resulting in a decrease in storage stability and charging stability and filming.
Japanese Examined Patent Publication No.62-39428 Japanese Patent Publication No. 1992-030014 JP 2004-206081 A

  Therefore, an object of the present invention is to solve the above problems. That is, the present invention relates to an electrostatic latent image developing toner excellent in low temperature fixability and chargeability in a high temperature and high humidity environment, a method for producing an electrostatic latent image developing toner, an electrostatic latent image developer, and image formation. It is an object to provide a method and an image forming apparatus.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> An electrostatic latent image developing toner containing a binder resin, a colorant, and a release agent, having a weight average molecular weight (Mw) in the range of 70,000 to 300,000 and an acid value (AV ) Is an electrostatic latent image developing toner containing less than 3% by weight of a styrene copolymer having a range of 70 mgKOH / g to 220 mgKOH / g.

<2> The electrostatic latent image developing toner according to <1>, wherein the styrene copolymer is contained in an amount of more than 1 wt% and less than 3 wt%.
<3> The styrene copolymer has a weight average molecular weight (Mw) in the range of 100,000 to 250,000 and an acid value (AV) in the range of 70 mgKOH / g to 150 mgKOH / g. The toner for developing an electrostatic latent image according to <2>.

<4> The electrostatic latent image developing toner according to <1>, wherein the toner contains 1% by weight or less of the styrene copolymer.
<5> The styrene copolymer has a weight average molecular weight (Mw) in the range of 70,000 to 300,000 and an acid value (AV) in the range of 70 mgKOH / g to 220 mgKOH / g. The toner for developing an electrostatic latent image according to <4>.

<6> The method for producing a toner for developing an electrostatic latent image according to any one of <1> to <5>, wherein the binder resin includes a first binder resin and a second binder resin. A first resin fine particle dispersion liquid containing a binder resin and dispersing the first resin fine particles containing the first binder resin; a colorant dispersion liquid obtained by dispersing the colorant; A first dispersion containing at least the first resin fine particles, the colorant, and the release agent in a mixed dispersion obtained by mixing a release agent fine particle dispersion in which release agent fine particles made of a release agent are dispersed. A first aggregating step for forming the agglomerated particles, and a second agglomerated particles by forming the second agglomerated particles by attaching the second resin fine particles containing the second binder resin to the surface of the first agglomerated particles. And adjusting the pH of the mixed dispersion liquid that has undergone the second aggregation step, the second aggregated particles And stopping the growth of the mixed dispersion containing the second agglomerated particles whose growth has been stopped by the stopping step is equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. And fusing and coalescing by heating to a temperature, and the first aggregating step, the second aggregating step, the stopping step, and the fusing and coalescing step, In any of the steps, a method for producing a toner for developing an electrostatic latent image, wherein a styrene copolymer dispersion containing the styrene copolymer is added to the mixed dispersion.

<7> The method for producing a toner for developing an electrostatic latent image according to <2> or <3>, wherein the binder resin includes a first binder resin and a second binder resin. And a first resin fine particle dispersion liquid in which the first resin fine particles containing the first binder resin are dispersed, a colorant dispersion liquid in which the colorant is dispersed, and the release agent. In a mixed dispersion obtained by mixing a release agent fine particle dispersion in which release agent fine particles are dispersed and a styrene copolymer dispersion containing the styrene copolymer, at least the first resin fine particles and the colorant A first aggregating step for forming first agglomerated particles containing the styrene copolymer and the release agent, and a second aggregating agent containing the second binder resin on the surface of the first agglomerated particles. A second aggregating step in which resin fine particles are attached to form second agglomerated particles; and the second aggregating step. By adjusting the pH of the mixed dispersion that has passed, a stop step of stopping the growth of the second aggregated particles, and the mixed dispersion containing the second aggregated particles that have stopped growing by the stop step, An electrostatic latent image developing toner comprising: a fusing and fusing step of fusing and fusing by heating to a temperature equal to or higher than a glass transition point of the first resin fine particles or the second resin fine particles. It is a manufacturing method.

<8> The method for producing a toner for developing an electrostatic latent image according to <4> or <5>, wherein the binder resin includes a first binder resin and a second binder resin. And a first resin fine particle dispersion liquid in which the first resin fine particles containing the first binder resin are dispersed, a colorant dispersion liquid in which the colorant is dispersed, and the release agent. Forming first aggregated particles including at least the first resin fine particles, the colorant, and the release agent in a mixed dispersion obtained by mixing a release agent fine particle dispersion in which release agent fine particles are dispersed. An addition step of adding a styrene copolymer dispersion containing the styrene copolymer to the mixed dispersion that has undergone the second aggregation step, and the mixed dispersion that has undergone the addition step. A stop work for stopping the growth of the second aggregated particles by adjusting the pH of the liquid And the mixed dispersion containing the second aggregated particles whose growth has been stopped by the stopping step is heated to a temperature equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. And a coalescing process for coalescing, and in any of the first aggregating process, the second aggregating process, the stopping process, and the coalescing and coalescing process, A method for producing a toner for developing an electrostatic latent image, comprising adding a styrene copolymer dispersion containing the styrene copolymer to a mixed dispersion.

<9> An electrostatic latent image developer comprising the toner for developing an electrostatic latent image according to any one of <1> to <5>.

<10> A charging step for charging the surface of the image bearing member, and an electrostatic latent image developer containing at least an electrostatic latent image developing toner on the charged surface of the image bearing member according to image information. In an image forming method comprising at least a developing step for developing a toner image by developing the toner image, a transfer step for transferring the toner image on the image carrier to a recording medium, and a fixing step for fixing the toner image on the recording medium. The electrostatic latent image developing toner is the electrostatic latent image developing toner according to any one of <1> to <3>.

<11> A charging unit that charges the surface of the image bearing member, and an electrostatic latent image corresponding to image information on the surface of the image bearing member charged by the charging unit. An image including developing means for forming a toner image by developing with a latent image developer, transfer means for transferring the toner image on the image carrier to a recording medium, and fixing means for fixing the toner image to the recording medium. In the image forming apparatus, the electrostatic latent image developing toner is the electrostatic latent image developing toner according to any one of <1> to <3>. is there.

  According to the present invention, an electrostatic latent image developing toner excellent in low-temperature fixability and chargeability in a high-temperature and high-humidity environment, a method for producing an electrostatic latent image developing toner, an electrostatic latent image developer, and image formation A method and an image forming apparatus can be provided.

Hereinafter, the present invention will be described in detail.
<Toner for electrostatic charge development>
The electrostatic latent image developing toner of the present invention (hereinafter sometimes abbreviated as toner) is an electrostatic latent image developing toner containing at least a binder resin, a colorant, and a release agent. The styrene copolymer having a weight average molecular weight (Mw) in the range of 70000-300000 and an acid value (AV) in the range of 70 mgKOH / g to 220 mgKOH / g is characterized by containing less than 3% by weight. .

  In the production process of the electrostatic latent image developing toner, a solution containing an alkali-derived group IA metal element is generally used to adjust the pH of the dispersion. However, if the manufactured toner contains such a group IA metal element, the chargeability is lowered due to the interaction between the metal element and the binder resin (release agent) contained in the toner. There was concern.

  In the electrostatic charge developing toner, it is considered that the binder resin contained in the electrostatic charge developing toner contributes to the low-temperature fixability of the toner. However, when heat is applied at the time of toner production, the low-temperature fixing property of the electrostatic charge developing toner is lowered due to a decrease in low-temperature fixability inherent in the binder resin due to the compatibility between the binder resin and the release agent. Deterioration occurs.

For example, polyester is usually used as the binder resin contained in the electrostatic charge developing toner from the viewpoint of low-temperature fixing, and the compatibility between the binder resin and the release agent also contained in the toner is high. Since it is good, it is difficult to suppress a decrease in low-temperature fixability, and it is difficult to adjust the dispersibility and inclusion property of the release agent in the toner.
In particular, when an ester-based wax is used as a release agent, the inclusion property of the ester-based wax in the polyester resin can be made relatively good, but when polyester is used as the binder resin, Due to the compatibility between the ester-based wax and the polyester resin, the polyester resin inherently has a glass transition point that keeps the glass transition point higher, and the viscosity sharply decreases in a high temperature range, so-called sharp melt property cannot be sufficiently exhibited, Can interfere with low-temperature fixing.

  In the present invention, the toner for developing an electrostatic latent image contains at least a binder resin, a colorant, and a release agent, and has a weight average molecular weight (Mw) in the range of 70,000 to 300,000 and an acid. By containing less than 3% by weight of a styrene copolymer having a value (AV) in the range of 70 mgKOH / g to 220 mgKOH / g, it is possible to suppress low temperature fixability and decrease in toner chargeability under high temperature and high humidity. Has been found to be possible.

The styrene copolymer having the above weight average molecular weight and acid value added to the toner is not fused or compatible with the binder resin due to its molecular weight, and is combined with or coalesced with toner particles, or at the time of toner production. It escapes out of the toner particles during a known cleaning process. At this time, it is considered that the alkali-derived Group IA metal element added for pH adjustment at the time of toner production also escapes from the toner particles together with the styrene copolymer.
For this reason, the toner of the present invention can suppress the hygroscopic property of the toner by suppressing the group IA metal element from remaining in the toner, and can stabilize the charging property under high temperature and high humidity. Conceivable. In addition, since the compatibility between the binder resin and the release agent can be suppressed, it is possible to suppress a decrease in the sharp melt property of the binder resin and to suppress a decrease in the low-temperature fixability of the toner. .

  Furthermore, in the toner of the present invention, the styrene copolymer is preferably contained in an amount of more than 1% by weight and less than 3% by weight. When the styrene copolymer is contained in an amount of more than 1% by weight and less than 3% by weight, the weight average molecular weight (Mw) of the styrene copolymer is in the range of 100,000 to 250,000, and the acid value (AV) Is preferably in the range of 70 mg KOH / g to 150 mg KOH / g.

  In the toner of the present invention, when the content of the styrene copolymer is more than 1% by weight and less than 3% by weight, the styrene copolymer can be disposed around the release agent in the toner. . Therefore, the release agent can be present alone in the toner, and the dispersibility of the release agent in the toner can be improved.

  When the content of the styrene copolymer contained in the toner is more than 1% by weight and less than 3% by weight, an ester wax is used as the release agent, so that the phase of the binder resin and the release agent is reduced. Solubility can be suitably suppressed. This is presumably because the styrene copolymer is present at the interface between the binder resin and the release agent, thereby enhancing the dispersibility of the release agent and preventing compatibility between the two. As described above, the compatibility between the binder resin and the release agent can be suppressed, so that the sharp melt property of the binder resin can be suppressed and the low temperature fixability of the toner can be suppressed. Can do.

Further, the styrene copolymer that has become excessive with respect to the release agent does not fuse with the binder resin due to its molecular weight, but escapes from the toner particles together with the fusion and coalescence of the toner particles. At this time, it is considered that the alkali-derived Group IA metal element added by adjusting pH or the like is also removed from the toner particles because the styrene copolymer has a high acid value.
By removing this group IA metal element from the toner, it is possible to suppress the hygroscopicity of the toner and to stabilize the charging property under high temperature and high humidity.

  As described above, in the toner of the present invention, in order to obtain the dispersibility of the release agent in addition to the low temperature fixability and the suppression of the decrease in chargeability in a high temperature and high humidity environment, the styrene copolymer is used in an amount of more than 1% by weight. In addition, it is essential to contain 3% by weight or less, preferably 1.4% by weight or more and 2.8% by weight or less, and particularly preferably 1.8% by weight or more and 2.5% by weight or less.

  When the content of the styrene copolymer contained in the toner is 1% by weight or less, the dispersibility of the release agent is deteriorated, and when it is 3% by weight or more, the charging property of the toner can be suppressed. There is a problem that it becomes difficult and the chargeability deteriorates.

  When the content of the styrene copolymer contained in the toner is more than 1% by weight and less than 3% by weight, the acid value (AV) of the styrene copolymer is greater than 70 mgKOH / g and It is preferably in the range of 150 mgKOH / g or less, preferably in the range of greater than 80 mgKOH / g and in the range of 140 mgKOH / g or less, particularly preferably in the range of greater than 80 to ≦ 120.

  Specific examples of the styrene copolymer having such an acid value (AV) and weight average molecular weight (Mw) include Joncryl 450, Joncryl 632, Joncryl 1535, and PDX7677. Among these, Joncrill 450 is preferably used from the viewpoint of the stability of the dispersion.

  When the content of the styrene copolymer contained in the toner is more than 1% by weight and less than 3% by weight, the acid value (AV) of the styrene copolymer is 70 mgKOH / g or less. It may be difficult to effectively remove the group IA metal element. On the other hand, if the acid value (AV) exceeds 150 mgKOH / g, it is not possible to obtain an appropriate viscosity of the mixed dispersion liquid of various materials added for toner production at the time of toner production, and fine powder increases, that is, sharp There is a problem that a toner having a fine particle size distribution cannot be obtained.

The acid value is measured as follows. The basic operation conforms to JIS K-0070-1992.
The sample was used after removing the THF-insoluble component of the styrene copolymer in advance, or a soluble component extracted with a THF solvent by a Soxhlet extractor obtained by measurement of the above-described THF-insoluble component was used as the sample. 1.5 g of the pulverized sample was precisely weighed, and the sample was 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)

  The amorphous resin particle dispersion used in the present invention is practically synthesized by an emulsion polymerization method. Therefore, it is necessary to remove the surfactant in the dispersion for measurement of the resin acid value. is there. The amorphous resin particle dispersion was placed in a semipermeable membrane, the surfactant was removed by dialysis, and the acid value was measured using this as an amorphous resin.

  When the toner of the present invention contains more than 1% by weight and less than 3% by weight of the styrene copolymer, the weight average molecular weight (Mw) of the styrene copolymer is larger than 100,000 and not more than 250,000. Is more preferably in the range of more than 120,000 and not more than 230000, particularly preferably in the range of more than 130,000 and not more than 210000.

When the content of the styrene copolymer contained in the toner is more than 1% by weight and less than 3% by weight, the weight average molecular weight (Mw) of the styrene copolymer is 100000 or less. In the coalescence and coalescence process, fusion between the styrene copolymer and the release agent occurs, and it becomes difficult to remove the styrene copolymer that has become excessive during the known washing process in toner production.
When the weight average molecular weight (Mw) of the styrene copolymer is 250,000 or more, it becomes difficult to encapsulate the styrene copolymer in an amount necessary for dispersing the release agent in the toner.

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

  On the other hand, in the toner of the present invention, the styrene copolymer is preferably contained in an amount of 0.01% by weight to 1% by weight. When the styrene copolymer is contained in an amount of 0.01% by weight or more and 1% by weight or less, the weight average molecular weight (Mw) of the styrene copolymer is in the range of more than 70000 and 300000 or less, and the acid value. (AV) is preferably in the range of more than 70 mgKOH / g and not more than 220 mgKOH / g.

  In the toner of the present invention, when the content of the styrene copolymer is 1% by weight or less, the charging property under low temperature and low humidity and the charging property under high temperature and high humidity, particularly in a high temperature and high humidity environment. It is possible to suppress a decrease in chargeability of the toner after being left for a long time with respect to the chargeability before being left for a long time.

Usually, in a toner using a crystalline resin and an amorphous resin in combination, the dispersion state of the crystalline resin is the key to determine the chargeability regardless of the production method. That is, when a crystalline resin having a low resistance is present on the toner surface, the electric charge frictionally charged in the developing machine provided in the electrophotographic image forming apparatus escapes through the crystalline resin. For this reason, it is necessary to suppress the surface exposure of the crystalline resin as much as possible.
In the kneading and pulverization method, when the crystalline resin and the amorphous resin are not so compatible, the pulverization interface tends to coincide with the interface between the crystalline resin and the amorphous resin. If the crystalline resin and the amorphous resin are compatible with each other not only by the kneading and pulverization method, but also when the crystalline resin and the amorphous resin are compatible, the incompatible crystalline resin will be dispersed throughout the toner. Are exposed on the toner surface.

Here, the amount of the crystalline resin exposed on the surface increases with the total amount of the crystalline resin used. If the amount of the crystalline resin contained in the toner is small, the amount of the crystalline resin exposed to the toner particle surface is small, and adverse effects on charging can be suppressed, but the low-temperature fixability depends on the physical properties of the bulk amorphous resin. It gets worse. On the other hand, when the amount of the crystalline resin contained in the toner is increased, the low-temperature fixability is improved, but the amount of exposure to the toner particle surface is increased, and the charging property is deteriorated.
This problem also occurs when a crystalline substance such as a release agent is exposed on the surface even when the toner does not contain a crystalline resin as a binder resin.

The core-shell toner, which is known in the prior art, is a core-shell toner in which a crystalline resin-containing core is completely covered with an amorphous resin. This makes it possible to achieve both low-temperature fixability and chargeability by containing a sufficient amount of crystalline resin for low-temperature fixing and suppressing the surface exposure of the crystalline resin.
However, even such a toner is not sufficiently charged after being charged once and then left for a long time under high temperature and high humidity.

  As a result of repeated studies by the present inventors, it has been clarified that there is a correlation between the charge retention at high temperature and high humidity and the Group IA metal element remaining in the toner.

  Taking sodium as an example of the Group IA metal element, regardless of whether it is amorphous or crystalline, the polyester resin has a carboxyl group at the terminal or side chain. It is considered that a part of sodium ions derived from sodium hydroxide added during the toner production process remains in the toner while being attracted to the charge of the carboxyl group or ester group. Such a sodium-bonded substituent causes the hygroscopicity to increase, and as a result, the chargeability and charge retention of the toner under high temperature and high humidity deteriorate.

  In the present invention, the toner contains a styrene copolymer having a weight average molecular weight (Mw) of more than 70,000 and not more than 300,000 and an acid value (AV) of more than 70 mgKOH / g and not more than 220 mgKOH / g. 1% by weight or less, the charging property under low temperature and low humidity and the charging property under high temperature and high humidity, in particular, the charging of the toner after being left in a high temperature and high humidity environment for a long time before being left for a long time. It has been found that a decrease in chargeability with respect to properties can be suppressed.

  In the toner of the present invention, when the content of the styrene copolymer within the range of the weight average molecular weight and the range of the acid value is 1% by weight or less, when the toner is produced, The coalescence functions as a metal filter for preventing the Group IA metal element from entering the toner. Since this styrene copolymer has a high molecular weight, it is not compatible with the binder resin regardless of crystallinity or non-crystallinity and is removed together with the Group IA metal element in a known washing step in toner production.

Thus, in the toner manufacturing process, it is possible to prevent the Group IA metal element from entering the toner, and to suppress the Group IA metal element from remaining in the manufactured toner. Compared with the case where the copolymer is contained in an amount of more than 1% by weight and less than 3% by weight, the group IA metal element remaining in the toner can be removed more completely.
For this reason, it is possible to suppress a decrease in chargeability after leaving the toner after being left in a high temperature and high humidity environment for a long time with respect to the chargeability before being left for a long time.

  In the toner of the present invention, as described above, the charging property under low temperature and low humidity and the charging property under high temperature and high humidity, in particular, the charging of the toner after being left in a high temperature and high humidity environment for a long time before being left for a long time. In order to suppress a decrease in chargeability after standing for the toner, the toner must contain 0.01% by weight to 1% by weight of a styrene copolymer, and 0.02% by weight to 1% by weight. % Or less, preferably 0.02% by weight or more and 0.08% by weight or less.

  Specific examples of the styrene copolymer having such an acid value (AV) and weight average molecular weight (Mw) include PDX7630A, PDX7692, PDX7182, and Joncryl 450. Among these, PDX7630A is preferably used from the viewpoint of toner detergency.

  If the content of the styrene copolymer contained in the toner is less than 0.01% by weight, there is a problem that the Group IA metal element cannot be sufficiently removed. Therefore, it is difficult to suppress a decrease in chargeability of the toner after being left for a long time with respect to the chargeability before being left for a long time.

  When the content of the styrene copolymer contained in the toner is 0.01% by weight or more and 1% by weight or less, the acid value (AV) of the styrene copolymer is greater than 70 mgKOH / g and 220 mgKOH / g It is essential to be in the range of g or less, preferably in the range of 130 and 220 or less, particularly preferably in the range of 170 or more and 210 or less.

  Note that the acid value (AV) of the styrene copolymer is higher than 70 mg KOH / g and not higher than 220 mg KOH / g, and the higher the acid value, the more the IA group element contained in the produced toner is extracted from the toner. It can be removed almost completely, which is preferable.

  When the content of the styrene copolymer contained in the toner is 1% by weight or less, and the acid value (AV) of the styrene copolymer is 70 mgKOH / g or less, the Group IA metal element added at the time of toner preparation May be difficult to remove effectively. In addition, the styrene copolymer of the present invention is practically added as a dispersion at the time of toner preparation, but when the acid value (AV) exceeds 220 mgKOH / g, the weight average molecular weight (Mw) described later is obtained. It is practically difficult to stably produce a dispersion of a styrene copolymer within the range.

  When the content of the styrene copolymer contained in the toner is 1% by weight or less, it is essential that the weight average molecular weight (Mw) of the styrene copolymer is greater than 70000 and less than or equal to 300000. Preferably, it is larger than 100,000 and not more than 300,000, more preferably larger than 150,000 and not more than 280000.

When the weight average molecular weight (Mw) of the styrene copolymer is 70000 or less when the content of the styrene copolymer contained in the toner is 1% by weight or less, Fusion of the styrene copolymer and the release agent occurs, and it becomes difficult to remove the Group IA metal element during a known cleaning step in toner production.
On the other hand, if the weight average molecular weight (Mw) of the styrene copolymer exceeds 300,000, the fixed image becomes brittle and the low-temperature fixability of the toner decreases.

  The weight average molecular weight (Mw) and acid value (AV) were measured under the same conditions as described above.

  Details of the components and production method of the toner of the present invention will be described below.

(Binder resin)
The binder resin used in the toner of the present invention may be an amorphous resin alone or a crystalline resin alone, but the crystalline resin and the amorphous resin may be mixed and used at the same time. preferable.

The ratio of the crystalline resin to the total components constituting the binder resin is preferably in the range of 10% to 70% by weight. When the proportion of the crystalline resin is less than 30%, the produced toner has good fixing characteristics when used as a toner of an electrophotographic image forming apparatus, but a phase separation structure in a fixed image. May become non-uniform, resulting in a problem that the strength of the fixed image, particularly the scratching strength, is reduced, and the scratches are easily damaged.
On the other hand, when the ratio of the binder resin is 90% or more, the sharp melt property derived from the crystalline resin cannot be obtained, and plasticity may occur simply. When used as a toner in an electrophotographic image forming apparatus. In addition, toner blocking resistance and image storage stability cannot be maintained while ensuring good low-temperature fixability.

  The “crystallinity” of the above “crystalline resin” means that in differential scanning calorimetry (DSC), it has a clear endothermic peak, not a stepwise change in endothermic amount. It means that the half-value width of the endothermic peak when measured at a temperature rate of 10 (° C./min) is within 10 ° C. On the other hand, a resin whose half width exceeds 10 ° C. or a resin with no clear endothermic peak means an amorphous resin (amorphous resin), but as an amorphous resin used in the present invention, it is clear. It is preferable to use a resin in which no endothermic peak is observed.

  In addition, it is preferable that the glass transition temperature of the amorphous resin in this invention is the range of 45-80 degreeC, and it is more preferable that it is the range of 50-70 degreeC. When the glass transition temperature is less than 45 ° C., the toner tends to easily block during storage or in the developing device (a phenomenon in which toner particles are aggregated into a lump). On the other hand, if the glass transition temperature exceeds 80 ° C., the toner fixing temperature increases, which is not preferable.

  The crystalline resin is not particularly limited as long as the resin has crystallinity, and a known resin material can be used.

  For example, styrenes; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, lauryl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, lauryl methacrylate, methacryl Esters having a vinyl group such as ethylhexyl acid, vinyl acetate, vinyl benzoate; carboxylic acids having a double bond such as methyl maleate, ethyl maleate, butyl maleate; olefins such as ethylene, propylene, butylene, butadiene Carboxylic acids having a double bond such as acrylic acid, methacrylic acid, maleic acid, etc .; and those obtained by polymerization or copolymerization of two or more types, and those obtained by mixing these.

  Furthermore, an epoxy resin, a melamine resin polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, or a mixture of these with the vinyl resin, or a graft obtained when a vinyl monomer is polymerized in the presence of these resins. A polymer etc. are mentioned.

  As the crystalline resin contained in the toner of the present invention, when used as a toner of an electrophotographic image forming apparatus, the details of which will be described later, fixing property to paper at the time of fixing, charging property, and melting point adjustment within a preferable range From this point of view, it is preferable to use a crystalline polyester resin. It is more preferable to use an aliphatic crystalline polyester resin having an appropriate melting point.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the present invention, a copolymer obtained by copolymerizing other components in a proportion of 50% by weight or less with respect to the crystalline polyester main chain is also referred to as crystalline polyester.

  The method for producing the crystalline polyester resin is not particularly limited, and can be produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. Depending on the type of monomer, it can be used separately.

  The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 to 230 ° C., and the reaction is carried out while reducing the pressure in the reaction system as necessary to remove water and alcohol generated during condensation. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  Catalysts that can be used in the production of the crystalline polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compounds: Phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like, and specific examples include the following compounds.

  Specifically, for example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium Tetraethoxide, titanium tetrapropoxide, titanium tetraisoproxide, titanium tetrabutoxide, 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, Li phenyl phosphite, tris (2, 4-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

The molecular weight of the crystalline resin is not particularly limited, but the weight average molecular weight is preferably 8000 or more, and more preferably 10,000 or more. However, it is preferably 100,000 or less, and more preferably 70000 or less. If the weight average molecular weight of the crystalline resin is less than 8000, there is a risk that the strength of the fixed image will be insufficient, or crushing may occur while stirring the developing device. Further, if the weight average molecular weight of the crystalline resin is larger than 100,000, the fixing temperature may be increased.
In addition, the measurement of the said molecular weight can be performed similarly to the molecular weight measuring method of the said styrene copolymer.

  As melting | fusing point of crystalline resin, Preferably it is 50-120 degreeC, More preferably, it is 60-110 degreeC. If the melting point is lower than 50 ° C., the storage stability of the toner and the storage stability of the toner image after fixing may become a problem. On the other hand, if the melting point is higher than 120 ° C., sufficient low-temperature fixing cannot be obtained as compared with the conventional toner. There is a case.

Here, the melting point of the crystalline resin was measured by ASTM / D3418-8 when a differential scanning calorimeter (DSC) was used and the temperature was measured from room temperature to 150 ° C. at a heating rate of 10 ° C. per minute. It can be determined as the melting peak temperature of the differential scanning calorimetry shown.
A crystalline resin may show a plurality of melting peaks, but in the present invention, the maximum peak is regarded as the melting point.

For the measurement of the maximum peak, for example, DSC-7 manufactured by Perkin Elmer is used. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.
The glass transition point and melting point of the binder resin described above were also measured by the same method as described above.

  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 the present specification, the description “(meth) acryl” means to include both “acryl” and “methacryl”.

On the other hand, as the amorphous resin, a known resin material can be used, but an amorphous polyester resin is particularly preferable.
The amorphous polyester resin used in the present invention is obtained mainly by condensation polymerization of polyvalent carboxylic acids and polyhydric alcohols.

  Examples of the polyvalent carboxylic acids used in the production of the amorphous polyester resin used in the present invention include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and diphene. Aromatic dicarboxylic acids such as acids, aromatic oxycarboxylic acids such as p-oxybenzoic acid, p- (hydroxyethoxy) benzoic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, adipic acid, azelaic acid, sebacic acid, Aliphatic dicarboxylic acids such as dodecane dicarboxylic acid, fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dimer acid, trimer acid, hydrogenated dimer acid, cyclohexanedicarboxylic acid, cyclohexene Unsaturated aliphatics and fats such as dicarboxylic acids The family dicarboxylic acid, also can be used other trimellitic acid as a polycarboxylic acid, trimesic acid, and the like trivalent or higher polyvalent carboxylic acids such as pyromellitic acid.

  Examples of the polyhydric alcohols used for producing the amorphous polyester resin include aliphatic polyhydric alcohols, alicyclic polyhydric alcohols, aromatic polyhydric alcohols, and the like. Aliphatic polyhydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, Ring opening of lactones such as neopentyl glycol, diethylene glycol, dipropylene glycol, dimethylol heptane, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ε-caprolactone Examples include aliphatic diols such as lactone-based polyester polyols obtained by polymerization, triols such as trimethylolethane, trimethylolpropane, glycerin, and pentaerythritol, and tetraols.

  Alicyclic polyhydric alcohols include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tricyclodecane Examples include diol, tricyclodecane dimethanol, dimer diol, hydrogenated dimer diol and the like.

  As aromatic polyhydric alcohols, para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A and Examples thereof include propylene oxide adducts.

  A monofunctional monomer may be introduced into the polyester resin for the purpose of blocking the polar group at the terminal of the amorphous polyester resin and improving the environmental stability of the toner charging characteristics. Monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid Acid, tertiary butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, octanecarboxylic acid, lauric acid, stearyl Monocarboxylic acids such as acids and lower alkyl esters thereof, or monoalcohols such as aliphatic alcohols, aromatic alcohols, and alicyclic alcohols can be used.

  In the present invention, when a monofunctional monomer is introduced into an amorphous polyester resin, it is desirable to use polyvalent carboxylic acids containing 5 mol% or more of cyclohexanedicarboxylic acid, and further, use of cyclohexanedicarboxylic acid. The amount is preferably 10 mol% to 70 mol% in the polyvalent carboxylic acid, more preferably 15 mol% to 50 mol%, and still more preferably 20 mol% to 40 mol%. As the cyclohexanedicarboxylic acid, one or more of 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid can be used. Moreover, you may combine what substituted some hydrogen of the cyclohexane ring by the alkyl group etc. If the content of cyclohexanedicarboxylic acid is less than this range, the fixing characteristics cannot be exhibited. If the content is too large, the unit price of the resin increases, resulting in a problem in cost.

  The glass transition point of the amorphous polyester resin used in the present invention must be 50 ° C. or higher, and more preferably 60 ° C. or higher and lower than 90 ° C. When the glass transition point is lower than this, there is a tendency to aggregate during handling or storage, which may cause a problem in storage stability. On the other hand, when the temperature is 90 ° C. or higher, the fixability is deteriorated.

  Moreover, it is preferable that the softening point of the amorphous polyester resin used for this invention is the range of 60 to 90 degreeC. In a toner in which the softening temperature of the amorphous polyester resin is kept lower than this, the toner tends to aggregate during handling or storage, and the fluidity may be greatly deteriorated particularly during long-time storage. If the softening point is higher than this, the fixing property is hindered.

  The softening point here refers to a melt viscosity of 10 4 Pa · s (10) measured using a flow tester (manufactured by Shimadzu Corporation, CFT-500) with a nozzle having a diameter of 1 mm and a thickness of 1 mm at a load of 10 kgf (98 N). The temperature at 5 poise).

  In the toner of the present invention, it is desirable that the amorphous resin and the crystalline resin are appropriately compatible. If the amorphous resin and the crystalline resin are completely compatible with each other, the toner viscosity may decrease too much at the time of melting, and the hot offset resistance may deteriorate. If the two are completely incompatible with each other, the crystalline resin is not taken into the toner and is discharged to the surface (rejection). As a result, the charging / powder / fixing characteristics of the toner are adversely affected. There is a case.

  In the method for producing a toner for developing an electrostatic latent image according to the present invention, of the first binder resin and the second binder resin, the first binder resin is a crystalline resin, and the second binder resin. The adhesive resin is preferably an amorphous resin, but both the first binder resin and the second binder resin may be amorphous resins.

(Colorant)
Known colorants can be used as the colorant contained in the toner of the present invention. For example, examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow NCG. Is given.

Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like.
Red pigments include Bengala, Cadmium Red, Red Plum, Mercury Sulfide, Watch Young Red, Permanent Red 4R, Risor Red, Brilliantamine 3B, Brilliantamine 6B, Daypon Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Red C Rose Bengal, Eoxin Red, Alizarin Lake and the like.

Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. For example, a rater.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.

  Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine. Furthermore, these can be used alone or in combination and further in a solid solution state.

  These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.

Further, these colorants are dispersed in an aqueous system by the homogenizer using a polar surfactant.
The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the resin constituting the binder resin.
When a magnetic material is used for the black colorant, 30 to 100 parts by weight is added unlike other colorants.

Further, when the toner is used as magnetism, magnetic powder may be contained. As such magnetic powder, a substance magnetized in a magnetic field is used, and it is a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite.
In particular, in the present invention, in order to obtain toner in the aqueous layer, it is necessary to pay attention to the water layer's ability to migrate, dissolve and oxidize, and surface modification, for example, hydrophobization treatment, etc. is preferably performed. Is preferred.

(Release agent)
As described above, the component constituting the toner of the present invention contains at least a binder resin including a crystalline resin and an amorphous resin, a colorant, and a release agent. .

Specific examples of the release agent include the following.
For example, waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, paraffin, and microcrystalline. And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, and chlorinated hydrocarbons, esters and ketones Synthetic waxes such as ether can also be used.

  Still other release agents include homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (eg, n-stearyl acrylate / ethyl methacrylate copolymer). And crystalline polymers having a long alkyl group in the side chain. Among these, more preferable are petroleum waxes such as paraffin wax and microcrystalline wax, and synthetic waxes.

  The content of the release agent with respect to all the components constituting the toner is preferably 10 to 40% by weight, more preferably 10 to 30% by weight, further preferably 15 to 30% by weight, and 15% by weight. ˜25% by weight is particularly preferred. If the content rate of a mold release agent is 10 weight% or more, sufficient mold release property can be ensured and generation | occurrence | production of hot offset can be prevented. On the other hand, if it is 40% by weight or less, the release agent is not exposed to the toner surface, and good fluidity and chargeability can be obtained.

(Other ingredients)
In addition, if necessary, a lubricant or a charge control agent may be added to the toner of the present invention.
Examples of the lubricant that can be used include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.

  The charge control agent is added to improve and stabilize the chargeability. For example, a dye composed of a complex such as a quaternary ammonium salt compound, a nigrosine compound, aluminum, iron, or chromium, or a triphenylmethane type Various commonly used charge control agents such as pigments can be used, but this affects the stability of the aggregated particles in the aggregation process and fusion / unification process when the toner is prepared by the emulsion aggregation method described later. From the standpoint of controlling ionic strength and reducing wastewater contamination, materials that are difficult to dissolve in water are preferred.

  In particular, as the charge control agent, metal salts of benzoic acid, metal salts of salicylic acid, metal salts of alkyl salicylic acid, metal salts of catechol, metal-containing bisazo dyes, tetraphenylborate derivatives, and the like used in powder toners. A compound selected from the group consisting of a quaternary ammonium salt and an alkylpyridinium salt, and a combination thereof can be preferably used.

  Further, when inorganic fine particles are added to the toner as a charge control agent, examples of such inorganic fine particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate and the like, which are usually outside the surface of the toner. Listed are all inorganic fine particles used as an additive. In this case, these inorganic fine particles can be used by being dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base or the like.

In the toner of the present invention, inorganic fine particles or organic fine particles can be added to the surface by applying a shearing force in a dry state for the purpose of use as a flow aid or a cleaning aid.
Examples of the inorganic fine particles include all particles usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide. Examples of the organic fine particles include all particles usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins.

  The volume average particle size of the inorganic fine particles is preferably in the range of 10 nm to 150 nm.

  In the present invention, the total amount of external additives is preferably 2% by weight or more, more preferably 3% by weight or more, based on all components constituting the toner. If it is less than 2% by weight, there may be insufficient voids and sufficient release of the release agent may not be obtained during fixing. In addition, as an upper limit of the total addition amount of an external additive, 10 weight% or less is preferable, More preferably, it is 8 weight% or less.

  The volume average particle diameter D50v of the toner of the present invention is preferably in the range of 4.0 to 10.0 μm, more preferably in the range of 5.0 to 8.0 μm, still more preferably 5.5 to 7 The range is 5 μm. If the thickness is 4.0 μm or more, it is possible to prevent the occurrence of cloud due to toner behavior. On the other hand, if it is 10.0 μm or less, a good quality image can be obtained.

  The particle size distribution of the toner of the present invention is preferably such that the volume average particle size distribution index (GSDv) is 1.30 or less and the number average particle size distribution index (GSDp) is 1.40 or less. If GSDv is 1.30 or less and GSDp is 1.40 or less, a high-quality image can be obtained.

  Further, the ratio (GSDv / GSDp) of the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is preferably 0.95 or more. However, when the volume distribution index GSDv exceeds 1.30, the resolution of the image may decrease, and the ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDp (GSDv / GSDp ) Is less than 0.95, toner chargeability may be reduced, toner scattering, fogging, and the like may occur, leading to image defects.

The values of the volume average particle size, volume average particle size distribution index GSDv, and number average particle size distribution index GSDp were measured and calculated as follows. First, the toner particle size distribution measured using Coulter Multisizer II (manufactured by Beckman-Coulter) is cumulatively distributed from the smaller diameter side with respect to the divided particle size range (channel) with respect to the volume and number of individual toner particles. , And the particle diameter of 16% cumulative is defined as volume average particle diameter D16v and number average particle diameter D16p, and the particle diameter of 50% cumulative is defined as volume average particle diameter D50v and number average particle diameter D50p. It is defined as Similarly, particle diameters that are 84% cumulative are defined as volume average particle diameter D84v and number average particle diameter D84p. The volume average particle size distribution index (GSDv) is defined as (D84v / D16v) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

In the toner of the present invention, the surface property index value represented by the following formula (2) is preferably 2 or less.
(Surface property index value) = (actual value of specific surface area) / (calculated value of specific surface area) (2)

However, in formula (2), the specific surface area calculated value is represented by 6Σ (n × R ² ) / {ρ × Σ (n × R ³ )}, where n is a Coulter The number of particles in the channel in the counter (number / channel) is represented, R represents the channel particle size (μm) in the Coulter counter, and ρ represents the toner density (g / μm ³ ). The number of divisions of the channel is 16. The size of the division is 0.1 interval on the log scale.

  Here, the surface property index value is preferably 2 or less, more preferably 1.8 or less. If it exceeds 2, the smoothness of the toner surface is impaired, and when an external additive is externally added to the toner surface, the external additive may be buried and the chargeability may be lowered.

  The calculated specific surface area is obtained by measuring the particle diameter of each channel of the Coulter counter and the number of particles of the particle diameter as shown in the equation (2) representing the calculated specific surface area, and converting each particle into a sphere. The particle size distribution was taken into account. Moreover, the specific surface area actual measurement value is measured based on the gas adsorption / desorption method, and is obtained by obtaining the Langmuir specific surface area. As a measuring device, Coulter SA3100 type (manufactured by Coulter, Inc.), Gemini 2360/2375 (manufactured by Shimadzu Corporation), or the like can be used.

Furthermore, the toner of the present invention preferably has a shape factor SF1 represented by the following formula (3) in the range of 120 to 135.
SF1 = (ML ² / A) × (π / 4) × 100 (3)
In the above formula (3), ML represents the maximum toner length (μm), and A represents the projected area of the toner (μm ² ).

  When the shape factor SF1 is less than 120, a cleaning failure may be caused when residual toner is removed after the transfer process. If the shape factor SF1 exceeds 135, transferability may be impaired. Further, when toner is used as a developer, the toner may be destroyed due to collision with a carrier in the developing device. In this case, as a result, the fine powder increases or the release agent component exposed on the toner surface may contaminate the surface of the photoreceptor and impair the charging characteristics. May cause problems.

The shape factor SF1 was measured as follows using a Luzex image analyzer (manufactured by Nireco Corporation, LUZEX III).
First, an optical microscopic image of toner spread on a slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projected area (A) of 50 or more toners are measured. The value of SF1 was obtained and averaged to obtain the shape factor SF1.

Next, a method for producing the toner of the present invention will be described.
The method for producing the toner of the present invention is not particularly limited, but includes the styrene copolymer having the acid value and the weight average molecular weight (Mw), and the content of the styrene copolymer is more than 1% by weight and 3% by weight. %, Or 0.01% by weight or more and 1% by weight or less, in practice, wet granulation methods such as emulsion polymerization aggregation method and suspension polymerization method, in particular, the method described below It is desirable to prepare by (emulsion polymerization aggregation method).

  That is, the toner of the present invention includes a first resin fine particle dispersion obtained by dispersing first resin fine particles, a colorant dispersion obtained by dispersing the colorant, and a release agent comprising the release agent. A first aggregated particle containing at least the first resin fine particles, the colorant, and the release agent is formed in a mixed dispersion obtained by mixing a release agent fine particle dispersion in which fine particles are dispersed. An aggregating step, a second aggregating step of forming second agglomerated particles by adhering second resin fine particles containing the second binder resin to the surface of the first agglomerated particles, and the second aggregating step. Adjusting the pH of the mixed dispersion that has undergone the agglomeration step to stop the growth of the second agglomerated particles, and the mixing comprising the second agglomerated particles that have stopped growing in the stopping step The dispersion is made from the first resin fine particles or the second resin fine particles. Fusing and coalescing by fusing and coalescing by heating to a temperature equal to or higher than the glass transition point of the fat fine particles, the first agglomeration step, the second agglomeration step, and the stopping step, It can be produced by adding a styrene copolymer dispersion containing the styrene copolymer to the mixed dispersion in any of the fusion and coalescence steps.

  Note that a styrene copolymer having a weight average molecular weight (Mw) greater than 100000 and less than or equal to 250,000 and an acid value (AV) greater than 70 mgKOH / g and less than or equal to 150 mgKOH / g is included in the toner. The toner containing more than 3% by weight and less than 3% by weight forms the first aggregated particles further containing the styrene copolymer by adding the styrene copolymer dispersion in the first aggregation step. By doing so, it can be manufactured.

  First, a production method when the toner contains the styrene copolymer in an amount of more than 1% by weight and less than 3% by weight will be described.

  In the first aggregation step, the pH of the mixed dispersion is adjusted to acidic in the mixed dispersion obtained by mixing the first resin particle dispersion, the colorant dispersion, and the release agent fine particle dispersion. As a result, aggregation occurs to form first aggregated particles containing at least first resin fine particles, a colorant, and a release agent.

  In the second aggregation step, the second aggregated particles are formed by attaching the second resin fine particles to the surface of the first aggregated particles.

  In addition, as pH in this 1st aggregation process and a 2nd aggregation process, pH 2.5-6 is preferable and pH 3-6 is more preferable.

In the first aggregation step and the second aggregation step, the first aggregated particles and the second aggregated particles to be formed are stably and rapidly aggregated, or the first aggregated particles having a narrower particle size distribution. In order to obtain the second aggregated particles, it is preferable to add an aggregating agent in the first aggregation step.
In the following description, when the first aggregated particles and the second aggregated particles are generically referred to, they are referred to as aggregated particles.

  As the flocculant, a compound having a monovalent or higher charge is preferable, and specific examples of the compound include water-soluble surfactants such as the above-mentioned ionic surfactants and nonionic surfactants, hydrochloric acid, sulfuric acid, and the like. Acids such as nitric acid, acetic acid, oxalic acid, magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, inorganic acid metal salts, sodium acetate, potassium formate, sulphate Fatty acids such as aliphatic acids such as sodium acid, sodium phthalate, potassium salicylate, metal salts of aromatic acids, metal salts of phenols such as sodium phenolate, metal salts of amino acids, triethanolamine hydrochloride, aniline hydrochloride And inorganic acid salts of aromatic and aromatic amines.

  In the toner of the present invention, in consideration of the stability of the aggregated particles, the stability of the coagulant with respect to heat and time, and the removal during washing, the trivalent metal salt of an inorganic acid and its polymer are used as the coagulant. In particular, aluminum flocculants are preferable in terms of performance and use. Specific examples include metal salts of inorganic acids such as aluminum chloride, aluminum sulfate, and aluminum nitrate, and inorganic metal salt polymers such as polyaluminum chloride.

  The addition amount of these flocculants varies depending on the valence of the charge, but both are small amounts, in the case of monovalent, about 3% by weight or less of the whole aggregate system, in the case of divalent, about 1% by weight or less, In the case of trivalent, it is about 0.5% by weight or less. Since the amount of the flocculant is preferably small, it is preferable to use a compound having a large valence.

Further, for example, a surfactant can be used for the purpose of stabilizing the dispersion of the resin fine particle dispersion, the colorant dispersion, and the release agent dispersion.
Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol type And nonionic surfactants such as alkylphenol ethylene oxide adducts and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable.

  In general, anionic surfactants have strong dispersing power and are excellent in dispersion of resin fine particles and colorants. Therefore, anionic surfactants can be used as surfactants for dispersing mold release agents. It is advantageous.

  The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, and castor oil sodium; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, and nonyl phenyl ether sulfate; lauryl sulfonate , Sodium alkylnaphthalene sulfonate such as dodecylbenzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate; sulfone such as naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate Acid salts; lauryl phosphate, isopropyl phosphate, nonylphenyl ether Phosphoric acid esters such as Sufeto; dialkyl sulfosuccinate salts such as sodium dioctyl sulfosuccinate; sulfosuccinate salts such as sulfosuccinate lauryl disodium; and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyldimethylammonium chloride, distearyldimethylammonium chloride, lauryldihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzene Trimethylammonium chloride, Quaternary ammonium salts such as quilts trimethyl ammonium chloride; and the like.

  Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And so on.

  The content of the surfactant in each dispersion may be a level that does not inhibit the present invention, generally a small amount, specifically in the range of about 0.01 to 10% by weight, More preferably, it is the range of 0.05-5 weight%, More preferably, it is the range of about 0.1-2 weight%. If the content is less than 0.01% by weight, each dispersion such as a resin particle dispersion, a colorant dispersion, and a release agent dispersion becomes unstable. There are problems such as the release of specific particles due to the difference in stability between them, and when the amount exceeds 10% by weight, the particle size distribution of the particles becomes wide and the control of the particle size becomes difficult. It is not preferable for the reason. In general, a suspension polymerization toner dispersion having a large particle size is stable even if the amount of the surfactant used is small.

  Next, in the stopping step, the growth of the second aggregated particles is stopped by adjusting the pH of the mixed dispersion liquid having undergone the second aggregation step to pH 6 to pH8.

In order to adjust the pH of the mixed dispersion to pH 6 to pH 8, it is preferable to add an alkaline solution containing a Group IA metal element.
Specific examples of the alkaline solution containing the IA metal element include an aqueous potassium hydroxide solution, an aqueous lithium hydroxide solution, and sodium hydroxide.
Especially, it is preferable to use sodium hydroxide aqueous solution from a viewpoint of cost.

  Next, in the fusion and coalescence step, the mixed dispersion containing the second aggregated particles whose growth has been stopped by the stopping step is set to a temperature equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. The toner can be obtained by fusing and coalescing with each other.

  In the method for producing a toner of the present invention, the mixed dispersion is added to the mixed dispersion liquid in any one of the first aggregation step, the second aggregation step, the stop step, and the fusion and coalescence step. A styrene copolymer dispersion containing a styrene copolymer is added.

  When the content of the styrene copolymer relative to the toner is 1 to 3% by weight, the addition amount of the styrene copolymer is essential to be 5 to 20% by weight with respect to the charged amount of toner. It is preferably 15% by weight, particularly preferably 5 to 13% by weight. When the content of the styrene copolymer with respect to the toner is 0.01 to 1% by weight, it is essential that the content is 3 to 10% by weight, more preferably 3 to 8% by weight with respect to the charged amount of toner. .

  By adding a styrene copolymer in any one of the first aggregation step, the second aggregation step, the stop step, and the fusion coalescence step, the fusion coalescence step is performed. Through the process, the toner of the present invention can be produced.

  Next, the preferred method for producing the toner of the present invention will be described in detail.

  First, a preferred method for producing a toner containing the above styrene copolymer having an acid value and a weight average molecular weight (Mw) of more than 1% by weight and less than 3% by weight will be described.

  In the first aggregation step, first, a first resin fine particle dispersion, a colorant particle dispersion, a release agent particle dispersion, and a styrene copolymer dispersion are prepared.

The first resin fine particle dispersion can be prepared by dispersing the first resin fine particles prepared by known phase inversion emulsification or the like in a solvent using an ionic surfactant.
The colorant particle dispersion is prepared by dispersing a colorant of a desired color in a solvent using an ionic surfactant opposite in polarity to the ionic surfactant used in the preparation of the first resin fine particle dispersion. Prepare.

Examples of the solvent include an aqueous medium and an organic solvent.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. In the present invention, it is preferable to add and mix a surfactant in the aqueous medium. Although it does not specifically limit as surfactant, For example, anionic surfactants, such as sulfate ester type, sulfonate type, phosphate ester type, soap type; amine salt type, quaternary ammonium salt type, etc. Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like.
Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. Among these, ionic surfactants such as anionic surfactants and cationic surfactants are preferable.
Examples of the organic solvent include ethyl acetate and toluene, which are appropriately selected according to the binder resin.

  The first resin particles and the second resin fine particles are homopolymers or copolymers of vinyl monomers such as esters having the vinyl group, vinyl nitrites, vinyl ethers, vinyl ketones ( In the case of a vinyl resin), the vinyl monomer is homopolymerized or copolymerized (vinyl type) by subjecting the vinyl monomer to emulsion polymerization or seed polymerization in an ionic surfactant. A dispersion obtained by dispersing resin particles made of (resin) in an ionic surfactant is prepared.

  When the first resin particles and the second resin fine particles are resins other than the homopolymer or copolymer of the vinyl monomer, the resin has an oiliness with a relatively low solubility in water. If it is dissolved in a solvent, the resin is dissolved in the oily solvent, and this solution is dispersed in water with an ionic surfactant or a polymer electrolyte using a dispersing machine such as a homogenizer, and then heated or heated. By dispersing the oily solvent under reduced pressure, a dispersion liquid in which resin particles other than vinyl resin are dispersed in an ionic surfactant is prepared.

  On the other hand, when the first resin and the second resin fine particles are crystalline polyester and amorphous polyester resin, they have a self-water dispersibility containing a functional group that can be anionic by neutralization and become hydrophilic. A stable aqueous dispersion can be formed under the action of an aqueous medium in which part or all of the obtained functional groups are neutralized with a base. In the crystalline polyester and the amorphous polyester resin, the functional group that can become a hydrophilic group by neutralization is an acidic group such as a carboxyl group or a sulfone group. As the neutralizing agent, for example, sodium hydroxide, potassium hydroxide, water Examples thereof include inorganic bases such as lithium oxide, calcium hydroxide, sodium carbonate and ammonia, and organic bases such as diethylamine, triethylamine and isopropylamine.

  Further, when a polyester resin that does not disperse in water, that is, does not have self-water dispersibility, is used as a binder resin, the resin solution and / or an aqueous medium mixed with the resin solution, as described later, 1 μm easily when dispersed with a polymer electrolyte such as a surfactant, polymer acid, polymer base, etc., heated above the melting point, and treated with a homogenizer or pressure discharge type disperser capable of applying a strong shear force The following microparticles can be made. When this ionic surfactant or polymer electrolyte is used, the concentration in the aqueous medium is suitably about 0.5 to 5% by weight.

  The release agent particle dispersion is a homogenizer that disperses the release agent in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, and heats above the melting point and applies strong shear. It is prepared by making fine particles with a pressure discharge type disperser.

  The styrene copolymer dispersion is prepared by transfer emulsion of a styrene copolymer resin obtained by a known radical polymerization method or emulsion polymerization from each constituent monomer.

The center diameter (median diameter) of each particle in the mixed dispersion thus obtained is preferably 1 μm or less, more preferably in the range of 50 to 400 nm, and in the range of 70 to 350 nm. More preferably it is.
The center diameter of each fine particle can be measured, for example, with a laser diffraction particle size distribution measuring device (LA-700, manufactured by Horiba, Ltd.).

  Next, in the mixed dispersion obtained by mixing the adjusted first resin fine particle dispersion, the colorant dispersion, the release agent particle dispersion, the styrene copolymer dispersion, and the flocculant, The first resin fine particles, the colorant, the release agent fine particles, and the styrene copolymer are hetero-aggregated to have a diameter approximately close to a desired toner diameter, the first resin fine particles, the colorant, and the release agent. Aggregated particles (first agglomerated particles) containing mold material fine particles and a styrene copolymer are formed.

  In the second aggregating step, the second resin fine particles are attached to the surface of the first agglomerated particles obtained in the first aggregating step by using the second resin fine particle dispersion containing the second resin fine particles. Thus, by forming a coating layer (shell layer) having a desired thickness, aggregated particles (core / shell aggregated particles) having a core / shell structure in which a shell layer is formed on the surface of the first aggregated particles are obtained.

  The second resin fine particles used at this time may be the same as or different from the first resin fine particles.

  The particle diameters of the first resin fine particles, the second resin fine particles, the colorant particles, and the release agent particles used in the first aggregation process and the second aggregation process are the toner diameter and the particle size, respectively. In order to easily adjust the distribution to a desired value, it is preferably 1 μm or less, and more preferably in the range of 100 to 300 nm.

  In the first aggregation step, the balance of the amounts of the two polar ionic surfactants (dispersants) contained in the first resin fine particle dispersion and the colorant dispersion can be shifted in advance. For example, an inorganic metal salt such as aluminum nitrate or a polymer of an inorganic metal salt such as polyaluminum chloride is ionically neutralized and heated at a temperature equal to or lower than the glass transition temperature of the first resin fine particles. Agglomerated particles can be produced.

  In such a case, in the second agglomeration step, the second resin fine particle dispersion treated with the polarity and the amount of the dispersant that compensates for the deviation in the balance between the two polar dispersants is added to the second agglomeration step. The core is added to the mixed dispersion containing one aggregated particle and further heated slightly below the glass transition temperature of the first aggregated particle or the second aggregated particle used in the second aggregation step as necessary. / Shell agglomerated particles can be produced.

  In the core / shell structure of the aggregated particles, the thickness of the shell layer is not particularly limited, but is preferably in the range of 150 to 300 nm. When the thickness of the shell layer is less than 150 nm, the release agent may flow out to the toner surface, and the discharged release agent may contaminate the photoreceptor or the like as a result. Further, when the thickness of the shell layer exceeds 300 nm, the slurry internal viscosity in the step of forming the core component decreases, and the number of resin fine particles added at the time of shell formation increases rapidly, so the internal slurry viscosity Greatly increases, the particle size and particle size distribution may deteriorate during shell formation. In addition, fine particles are easily generated when the shell is formed, and toner manufacturing problems such as clogging when the toner slurry containing such residual resin fine particles is solid-liquid separated and removed with a filter or the like are likely to occur. There is a case.

  In addition, the 1st aggregation process and the 2nd aggregation process may be repeatedly performed in steps divided into a plurality of times.

  In the first aggregation step or the stop step performed after passing through the first aggregation step and the second aggregation step, the second aggregation formed by obtaining the first aggregation step and the second aggregation step. By adding an alkaline solution containing a Group IA metal element to the mixed dispersion containing particles, the pH of the mixed dispersion is controlled within the range of 6.0 to 8.0, thereby stopping the progress of aggregation.

  Next, in the coalescence and coalescence process, the glass transition temperature of the first resin fine particles or the second resin fine particles contained in the second aggregated particles obtained by stopping the progress of the aggregation by obtaining the stop process (the resin type is 2). In the case of more than one kind, toner particles are obtained by heating above the glass transition temperature of the resin having the highest glass point transition temperature) and fusing and coalescing.

  In this fusion and coalescence process, the styrene copolymer that has become excessive in the toner has a high weight average molecular weight (Mw), so it is not fused with the binder resin, and the fusion particles are fused together with the outside of the toner particles. Go through. At this time, it is considered that the Group IA metal element added for adjusting the pH also escapes to the outside of the toner because the styrene copolymer has a high acid value.

  After completion of the coalescence and coalescence process, the toner particles formed in the mixed dispersion liquid are converted into toner particles that have been dried through a known washing process, solid-liquid separation process, and drying process.

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

  Next, a styrene copolymer having a weight average molecular weight (Mw) of more than 70,000 and not more than 300,000 and an acid value (AV) of more than 70 mgKOH / g and not more than 220 mgKOH / g, A preferred method for producing a toner containing 0.01% by weight or more and 1% by weight or less will be described.

  When a toner containing 0.01% by weight or more and 1% by weight or less of the styrene copolymer having the acid value (AV) and the weight average molecular weight (Mw) is prepared, the toner is subjected to the second aggregation step. In addition, it is preferable to add the styrene copolymer having the acid value and the weight average molecular weight (Mw) to the mixed dispersion before the upper stopping step from the viewpoint of removing excess styrene copolymer.

  Therefore, in the case of producing a toner containing 0.01% by weight or more and 1% by weight or less of a styrene copolymer, in the first aggregation step, the first resin fine particle dispersion, the colorant dispersion, In the mixed dispersion obtained by mixing the release agent particle dispersion and the flocculant, the first resin fine particles, the colorant, and the release agent fine particles are hetero-aggregated to be close to the desired toner diameter. Aggregated particles (first aggregated particles) having a diameter and containing first resin fine particles, a colorant, and release agent fine particles are formed.

Then, the addition step is performed after the second aggregation step in the same manner as described above.
In the adding step, the styrene copolymer dispersion containing the styrene copolymer is added to the mixed dispersion containing the second aggregated particles formed by obtaining the first aggregation step and the second aggregation step.

  After obtaining this addition step, the pH of the mixed dispersion liquid containing the second agglomerated particles formed by obtaining the first agglomeration step and the second agglomeration step is set to 6.0 in the stopping step in the same manner as described above. The first resin fine particles contained in the second agglomerated particles obtained by stopping the agglomeration after the agglomeration process is stopped by obtaining a stop step in the coalescence coalescence process after stopping the agglomeration. Alternatively, the toner particles are obtained by heating above the glass transition temperature of the second resin fine particles to fuse and coalesce.

  After completion of the coalescence and coalescence process, similarly to the above, the toner particles formed in the mixed dispersion liquid are converted into toner particles that have been dried through a known washing process, solid-liquid separation process, and drying process.

As described above, when a toner containing the above-described styrene copolymer having an acid value and a weight average molecular weight (Mw) of 0.01% by weight or more and 1% by weight or less is used, a pH for stopping the progress of aggregation is obtained. It is necessary to add a styrene copolymer before the adjustment (stopping step).
When this styrene copolymer is added during the first aggregation process or the second aggregation process, the styrene copolymer is taken into the first aggregation particles or the second aggregation particles and does not function sufficiently as a metal filter. there is a possibility.
In addition, when the styrene copolymer is added during the fusion and coalescence step, since an alkali solution containing a group IA metal element for pH adjustment is added to the mixed dispersion as a stopping step, The effect of suppressing the deterioration of the chargeability of the toner after being left for a long time in a high-temperature and high-humidity environment, especially the toner after being left for a long time. May not be possible.

<Electrostatic latent image developer>
The electrostatic latent image developer of the present invention is not particularly limited except that it contains the toner for developing an electrostatic latent image of the present invention, and can have an appropriate component composition depending on the purpose. The electrostatic latent image developer in the present invention is a one-component electrostatic latent image developer when the electrostatic latent image developing toner is used alone, and a two-component electrostatic developer when used in combination with a carrier. It becomes a latent image developer.

  For example, in the case of using a carrier, the carrier is not particularly limited, and examples thereof include known carriers. For example, resins described in JP-A Nos. 62-39879 and 56-11461 are disclosed. Known carriers such as a coated carrier can be used.

  Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include normal iron powder, ferrite, magnetite molding, and the like, and the volume average particle size is in the range of about 30 to 200 μm.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, acrylic acid 2 -Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, etc. Vinyl nitriles; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl Homopolymers such as vinyl ketones such as ketones; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers comprising two or more types of monomers Furthermore, silicone resins containing methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by weight and more preferably in the range of 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the core particles.

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .

  The mixing ratio of the electrostatic latent image developing toner of the present invention and the carrier in the two-component electrostatic image developer is not particularly limited and may be appropriately selected depending on the purpose.

<Image Forming Apparatus and Image Forming Method>
Next, an image forming apparatus and an image forming method using the toner of the present invention will be described.

As shown in FIG. 1, the image forming apparatus 82 of the present invention includes the electrophotographic photoreceptor 80 that rotates in a predetermined direction (the direction of arrow D in FIG. 1).
In the vicinity of the electrophotographic photoreceptor 80, a charging device 84, an exposure device 86, a developing device 88, a transfer device 89, a charge eliminating device 81, and a cleaning member 87 are provided along the rotation direction of the electrophotographic photoreceptor 80. It has been.

  The charging device 84 charges the surface of the electrophotographic photoreceptor 80 to a predetermined potential. The exposure device 86 exposes the surface of the electrophotographic photoreceptor 80 charged by the charging device 84 to form an electrostatic latent image corresponding to the image data.

The developing device 88 stores in advance the developer containing the toner of the present invention as a developer containing toner for developing the electrostatic latent image, and supplies the stored developer to the surface of the electrophotographic photoreceptor 80. Thus, the electrostatic latent image is developed to form a toner image.
The transfer device 89 transfers the toner image formed on the electrophotographic photoreceptor 80 to the recording medium 83 by sandwiching and transporting the recording medium 83 with the electrophotographic photoreceptor 80. The toner image transferred to the recording medium 83 is fixed on the surface of the recording medium 83 by a fixing device (not shown).

  The static eliminator 81 neutralizes the charged deposit adhered to the surface of the electrophotographic photoreceptor 80. The cleaning member 87 is provided so as to come into contact with the surface of the electrophotographic photoreceptor 80 and removes surface deposits by frictional force with the surface of the electrophotographic photoreceptor 80.

  The image forming apparatus 82 of the present invention may be a so-called tandem machine having a plurality of electrophotographic photoreceptors 80 corresponding to the toners of the respective colors. The transfer of the toner image to the recording medium 83 may be an intermediate transfer method in which the toner image formed on the surface of the electrophotographic photoreceptor 80 is transferred to the intermediate transfer body and then transferred to the recording medium.

  The surface of the electrophotographic photoreceptor 80 rotating in a predetermined direction (the direction of arrow D in FIG. 1) is uniformly charged by the charging device 84. The exposure device 86 forms an electrostatic latent image corresponding to the image data on the surface of the electrophotographic photoreceptor 80 whose surface is uniformly charged. When the area where the electrostatic latent image is formed on the electrophotographic photoreceptor 80 reaches the area facing the developing device 88, the electrostatic latent image is developed by the developer stored in the developing device 88. As described above, the electrostatic latent image is developed by the developer, whereby a toner image corresponding to the electrostatic latent image is formed on the electrophotographic photoreceptor 80.

  When the area of the toner image formed on the electrophotographic photoreceptor 80 reaches the area facing the transfer device 89 due to the rotation of the electrophotographic photoreceptor 80, the toner image is transferred to the recording medium 83 in this area. Is done. When the recording medium 83 is conveyed by a conveyance roller (not shown) and reaches the installation position of the fixing device 90, the toner image transferred onto the recording medium 83 is heated and pressurized by the fixing device 90 to be recorded. It is fixed on the medium 83.

  According to the image forming apparatus 82 of the present invention, the toner that can suppress the low temperature fixability and the decrease in chargeability under high temperature and high humidity is used. Therefore, in the image forming apparatus 82, the low temperature environment or the high temperature and high humidity environment. The toner used in the image forming apparatus 82 has a low temperature fixing property and a high temperature and high humidity even when the image forming process is performed in the image forming process or when the image forming process is performed after being left in a high temperature and high humidity environment for a predetermined time or longer. Therefore, it is possible to suppress deterioration in image quality caused by one or both of low-temperature fixability and lowering of chargeability of the toner.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.

<Measuring method of various characteristics>
First, methods for measuring physical properties of toners and the like used in Examples and Comparative Examples will be described.
(Toner particle size and particle size distribution measurement method)
In the present invention, the toner particle size and particle size distribution were measured using a Coulter Multisizer II type (manufactured by Beckman-Coulter) as the measuring device, and ISOTON-II (manufactured by Beckman-Coulter) as the electrolyte.

  As a measurement method, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant. This was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 2 to 60 μm is measured using the Coulter Multisizer II type with an aperture diameter of 100 μm, The volume average particle diameter, GSDv, and GSDp were determined as described above. The number of particles to be measured was 50,000.

(Toner shape factor SF1 measurement method)
The toner shape factor SF1 is obtained by taking toner particles dispersed on a slide glass or an optical microscope image of the toner into a Luzex image analyzer through a video camera, obtaining the maximum length and projected area of 50 or more toners, and calculating the following formula ( It is obtained by calculating by 4) and obtaining the average value.
SF1 = (ML ² / A) × (π / 4) × 100 (4)
In the above formula (4), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

(Measurement method of molecular weight and molecular weight distribution of resin)
In the present invention, the molecular weight and molecular weight distribution of the binder resin and the like are those obtained 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 experimental conditions, an experiment was performed using a sample concentration of 0.5%, 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 fine particles, colorant particles, etc.)
For the volume average particle diameter of resin fine particles, colorant particles, etc., when the particle diameter to be measured is 2 μm or more, Coulter Multisizer II type (manufactured by Beckman-Coulter) is used as the measuring device, and the electrolyte is ISOTON-II ( The particle size was measured using a Beckman-Coulter company).

  As a measuring method, 0.5 to 50 mg of a measurement sample was added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Multisizer II type, an aperture having an aperture diameter of 100 μm is used, and the particle diameter is 2.0 to 60 μm. The particle size distribution of particles in the range was measured. The number of particles to be measured was 50,000.

  For the divided particle size range (channel), the measured particle size distribution is drawn from the small diameter side for each volume and number, and the particle size that is 16% cumulative by volume is accumulated by volume average particle size D16v and number. The cumulative number particle diameter of 16% is defined as D16p. Similarly, a particle diameter that is 50% cumulative in volume is defined as a volume average particle diameter D50v, and a particle diameter that is cumulative 50% in number is defined as a number average particle diameter D50p. Similarly, a particle diameter that is 84% cumulative in volume is defined as a volume average particle diameter D84v, and a cumulative particle diameter that is 84% cumulative in number is defined as D84p. The volume average particle diameter is the D50v.

Using these, the volume average particle size distribution index (GSDv) is calculated from (D84v / D16v) ^1/2 , the number average particle size index (GSDp) is calculated from (D84p / D16p) ^1/2 , and the small diameter side number average The particle size index (lower GSDp) is calculated by {(D50p) / (D16p)}.

  On the other hand, when the particle diameter to be measured was less than 2 μm, the particle size was measured using a laser diffraction particle size distribution analyzer (LA-700: manufactured by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The obtained volume average particle diameter for each channel was accumulated from the smaller volume average particle diameter, and the volume average particle diameter was determined to be 50%.

  When measuring powders such as external additives, 2 g of a measurement sample is added to 50 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, and 2 with an ultrasonic disperser (1,000 Hz). A sample was prepared by dispersing for a minute, and the measurement was performed in the same manner as the above dispersion.

(Measuring method of melting point and glass transition temperature of resin)
The glass transition point (Tg) of the amorphous resin and the melting point (Tm) of the crystalline resin were measured using a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001) according to ASTM D3418-8. It was determined by measuring from room temperature to 150 ° C. under a temperature rising rate of 10 ° C./min. The glass transition point was the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part, and the melting point was analyzed according to JIS standard (see JIS K-7121) as the temperature at the apex of the endothermic peak.

<Preparation of toner containing styrene copolymer in an amount of more than 1 wt% and not more than 3 wt%>

(Preparation of styrene copolymer dispersion (1))
・ Styrene (Wako Pure Chemical Industries): 280 parts ・ n-Butyl Acrylate (Wako Pure Chemical Industries): 120 parts ・ Acrylic acid (Rhodia Nikka): 106 parts ・ Maleic acid (Wako Pure Chemical Industries): 5.1 Parts 1'10 decanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.): 1.2 parts dodecane thiol (manufactured by Wako Pure Chemical Industries): 1.7 parts (A product of Dow Chemical Co., Ltd.) A solution prepared by dissolving 1.5 parts by mass in ion-exchanged water 550 parts by mass was added, dispersed and emulsified in a flask, and slowly stirred and mixed for 10 minutes. Next, 50 parts by mass of dissolved ion-exchanged water was added, and after sufficiently replacing the nitrogen in the flask, the solution in the flask was heated to 65 ° C. in an oil bath while stirring and heated to 5 ° C. During the emulsion polymerization is continued to obtain anionic styrenic copolymer dispersion (1).
The acid value (AV) of the styrene copolymer dispersion (1) was 170 mgKOH / g, and the weight average molecular weight Mw was 122,000.

(Preparation of styrene copolymer dispersion (2))
In the preparation of the styrene copolymer dispersion (1), a styrene copolymer dispersion was similarly prepared except that 55 parts of acrylic acid, 4.6 parts of maleic acid, and 2.6 parts of ammonium persulfate were used. (2) was obtained.
The acid value (AV) of the styrene copolymer dispersion (2) was 110 mgKOH / g, and the weight average molecular weight Mw was 278,000.

(Preparation of styrene copolymer dispersion (3))
In the preparation of the styrene copolymer dispersion (1), a styrene copolymer dispersion was similarly prepared except that 55 parts of acrylic acid, 4.6 parts of maleic acid, and 5.2 parts of ammonium persulfate were used. (3) was obtained.
The acid value (AV) of the styrene copolymer dispersion (3) was 110 mgKOH / g, and the weight average molecular weight Mw was 62000.

(Preparation of crystalline polyester resin dispersion (1))
In a heat-dried three-necked flask, an acid component (9,12 mol of 1,12-dodecanedicarboxylic acid and 4.0 mol% of sodium dimethyl-5-sulfonate isophthalate) and a diol component (1,10-decanediol) 100 mol%) and Ti (OBu) 4 (0.011% with respect to the acid component) as a catalyst, and then the pressure in the container is reduced by a depressurization operation, and an inert atmosphere is established with nitrogen gas. The mixture was refluxed at 180 ° C. for 6 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 220 ° C. by vacuum distillation, and the mixture was stirred for 2.5 hours. When it became viscous, vacuum distillation was stopped and air-cooled to obtain a crystalline polyester resin (1).

  When the melting point of the obtained crystalline polyester resin (1) was measured, it had a clear peak and the melting point was 74 ° C.

  Next, 180 g of this crystalline polyester resin (1) and 585 g of deionized water were placed in a stainless beaker, placed in a warm bath, and heated to 95 ° C. When the crystalline polyester resin (1) was melted, the mixture was stirred at 8000 rpm using a homogenizer (manufactured by IKA: Ultra Tarrax T50), and at the same time, diluted ammonia water was added to adjust the pH to 7.0. Next, 20 g of an aqueous solution obtained by diluting 0.8 g of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) is added dropwise to carry out emulsification and dispersion to disperse a crystalline polyester resin having a volume average particle size of 0.23 μm. Liquid (1) [resin particle concentration: 12.1%] was prepared.

(Preparation of amorphous polyester resin dispersion (1))
In a heat-dried three-necked flask,
・ Dimethyl 2,6-naphthalenedicarboxylate 123 parts ・ Dimethyl terephthalate 96 parts ・ Bisphenol A-ethylene oxide adduct 221 parts ・ Ethylene glycol 65 parts ・ Biphenol 5 parts ・ Tetrabutoxy titanate 0.07 parts The ester exchange reaction was carried out by heating at 0 ° C. for 180 minutes. Subsequently, the reaction was continued for 60 minutes at 220 ° C. with the pressure of the system being 1 to 10 Torr. As a result, an amorphous polyester resin (1) was obtained. The glass transition point of the polyester resin (1) was 78 ° C.

  Next, 115 parts by weight of this amorphous polyester resin (1), 180 parts by weight of deionized water, and 5 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) were heated to 120 ° C. Then, after sufficiently dispersing with a homogenizer (IKA: Ultra Tarrax T50), dispersion treatment is performed with a pressure discharge type gorin homogenizer for 1 hour, and an amorphous polyester resin dispersion having a volume average particle size of 0.25 μm (1) (Resin particle concentration: 40% by weight) was adjusted.

(Preparation of amorphous polyester resin dispersion (2))
In a heat-dried 3-neck flask,
・ Dimethyl terephthalate 164 parts ・ Dimethyl isophthalate 30 parts ・ Bisphenol A-ethylene oxide adduct 221 parts ・ Ethylene glycol 95 parts ・ Biphenol 5 parts ・ Tetrabutoxy titanate 0.07 parts were charged and heated at 170 to 220 ° C. for 180 minutes. A transesterification reaction was performed. Subsequently, the reaction was continued for 60 minutes at 220 ° C. with the pressure of the system being 1 to 10 Torr. As a result, an amorphous polyester resin (2) was obtained. The glass transition point of the polyester resin (2) was 73 ° C.

  Next, 115 parts of this amorphous polyester resin (2), 180 parts of deionized water, and 5 parts of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) were heated to 120 ° C. to obtain a homogenizer ( After sufficiently dispersing with IKA (Ultra Turrax T50), dispersion treatment is performed with a pressure discharge type gorin homogenizer for 1 hour, and an amorphous polyester resin dispersion (2) (resin particles) having a volume average particle size of 0.22 μm Density: 40%) was adjusted.

(Preparation of colorant particle dispersion)
-Colorant particle dispersion (1)-
・ Carbon black (Cabot, Regal 330) 30 parts ・ Anionic surfactant (Nippon Oil & Fats, Newlex R) 2 parts ・ Ion-exchanged water 220 parts

  The above components are mixed and pre-dispersed for 10 minutes with a homogenizer (Ultra Turrax, manufactured by IKA), and then subjected to dispersion treatment at a pressure of 245 mPa for 15 minutes using a counter impact type wet pulverizer (Altimizer, manufactured by Sugino Machine). A colorant particle dispersion (1) having a volume average particle diameter of 328 nm was obtained.

-Colorant particle dispersion (2)-
・ Copper phthalocyanine B15: 3 (manufactured by Dainichi Seika) 45 parts ・ Cationic surfactant (Neogen RK, Daiichi Kogyo Seiyaku) 5 parts ・ Ion-exchanged water 200 parts

  The above components are mixed and pre-dispersed for 10 minutes with a homogenizer (Ultra Turrax, manufactured by IKA), and then subjected to a dispersion treatment at a pressure of 245 mPa for 15 minutes using a counter impact wet pulverizer (Altimizer, manufactured by Sugino Machine). A colorant particle dispersion (2) having a volume average particle diameter of 385 nm was obtained.

(Preparation of release agent particle dispersion)
・ 52 parts of paraffin wax (HNP9) ・ 5 parts of cationic surfactant (Neogen RK, manufactured by Daiichi Kogyo Seiyaku) ・ 200 parts of ion-exchanged water

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

(Production of toner particles)
-Toner particles (A1)-
-Crystalline polyester resin dispersion (1) 240 parts-Amorphous polyester resin dispersion (1) 180 parts-Colorant dispersion 42 parts-Release agent particle dispersion 62 parts-Ion-exchanged water 350 parts-Jonkrill 450
18 parts or more (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 100 mg KOH / g, weight average molecular weight (Mw) 146000, resin particle concentration 42.0%) was accommodated in a round stainless steel flask and adjusted to pH 2.7 The mixture was mixed and dispersed for 5 minutes with a homogenizer (manufactured by IKA: Ultra Tarrax T50).
Next, 0.27 parts by weight of polyaluminum chloride was added thereto, and the dispersing operation was continued for 5 minutes with the ultra turrax. Further, the flask was heated to 44 ° C. with stirring in an oil bath for heating, and held at 44 ° C. for 120 minutes, and then 120 parts by weight of the amorphous polyester resin dispersion (1) was gradually added thereto.

  Then, 0.5 mol / L sodium hydroxide aqueous solution was added to adjust the pH in the solution to 8.0, and then the stainless steel flask was sealed and heated to 93 ° C. while continuing stirring using a magnetic seal. Hold for 3 hours.

  After holding for 3 hours (after completion of the reaction), the mixture was cooled, filtered, thoroughly washed with ion-exchanged water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 L of ion exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This operation was further repeated 5 times, and when the filtrate had a pH of 7.00, an electric conductivity of 8.8 μS / cm, and a surface tension of 71.0 Nm, solid-liquid separation was performed by Nutsche suction filtration using No5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner particles (A1).

The volume average particle diameter D50v of the toner particles (A1) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. In addition, the toner particle shape factor SF1 obtained by shape observation with a Luzex image analyzer was 131.
The content of the styrene copolymer (Joncrill 450) contained in the toner particles (A1) was calculated from the integral ratio of the proton peak by H-NMR measurement, and found to be 2.4% by weight. The NMR measurement conditions are as shown below.
Device: JNM-AL400 (manufactured by JEOL Ltd.)

Measurement condition container: Φ5 mm glass tube Solvent: deuterated chloroform solution Sample temperature: 23-25 ° C.
Observation nucleus: H
Integration count: 64 times Standard: TMS (TMS concentration 0.05% by volume with respect to solvent)
Sample concentration: 30 mg sample dissolved in 0.7 mL deuterated chloroform solution

-Toner particles (A2)-
In the production of the toner particles (A1), instead of Jonkrill 450, Jonkrill 632 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 82 mgKOH / g, weight average molecular weight (Mw) 120,000, resin particle concentration 42.0%) is used. The toner particles (A2) were prepared in the same manner except that 18 parts were used.

The volume average particle diameter D50v of the toner particles (A2) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, the content of the styrene copolymer (Joncrill 852) contained in the toner particles (A2) was measured in the same manner as in the toner particles (A1), and it was 2.3% by weight.

-Toner particles (A3)-
In the production of the toner particles (A1), PDX7182 is used instead of Jonkrill 450.
Toner particles (A3) were produced in the same manner except that 20 parts (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 125 mg KOH / g, weight average molecular weight (Mw) 153000, resin particle concentration 36.5%) were used. .

The volume average particle diameter D50v of the toner particles (A3) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer (PDX7182) contained in the toner particles (A3) was measured in the same manner as in the toner particles (A1), it was 1.9% by weight.

-Toner particles (A4)-
In the production of the toner particles (1), PDX7677 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 70 mgKOH / g, weight average molecular weight (Mw) 142000, resin particle concentration 46.0%) is used instead of Jonkrill 450. A toner particle (A4) was produced in the same manner except that the part was used.
The volume average particle diameter D50v of the toner particles (A4) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, the content of the styrene copolymer (PDX7677) contained in the toner particles (A4) was measured in the same manner as in the toner particles (A1) and found to be 2.6% by weight.

-Toner particles (A5)-
Preparation of toner particles (1) was performed in the same manner except that styrene copolymer dispersion (1) (acid value (AV) 170 mgKOH / g, weight average molecular weight (Mw) 122000) was used instead of Jonkrill 450. Thus, toner particles (A5) were produced.
The volume average particle diameter D50v of the toner particles (A5) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer contained in the toner particles (A5) was measured in the same manner as in the toner particles (A1), it was 1.5% by weight.

-Toner particles (A6)-
In the production of the toner particles (1), a styrene copolymer dispersion liquid (2) (acid value (AV) 110 mg KOH / g, weight average molecular weight (Mw) 278000) was used in place of Joncrill 450. Thus, toner particles (A6) were produced.
The volume average particle diameter D50v of the toner particles (A6) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer contained in the toner particles (A6) was measured in the same manner as in the toner particles (A1), it was 2.0% by weight.

-Toner particles (A7)-
In the production of the toner particles (A7), instead of Jonkrill 450, Jonkrill 7100 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 51 mgKOH / g, weight average molecular weight (Mw) 213000, resin particle concentration 48.0%) was used. Toner particles (A7) were prepared in the same manner except that 16 parts were used.

The volume average particle diameter D50v of the toner particles (A7) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer (Joncrill 7100) contained in the toner particles (A7) was measured in the same manner as in the toner particles (A1), it was 2.8% by weight.

-Toner particles (A8)-
Preparation of toner particles (1) was performed in the same manner except that styrene copolymer dispersion (3) (acid value (AV) 110 mgKOH / g, weight average molecular weight (Mw) 62000) was used instead of Jonkrill 450. Thus, toner particles (A8) were produced.
The volume average particle diameter D50v of the toner particles (A8) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer contained in the toner particles (A8) was measured in the same manner as in the toner particles (A1), it was 2.9% by weight.

-Toner particles (A9)-
Toner particles (A9) were prepared in the same manner as in the preparation of toner particles (A1) except that the amount of Joncrill 450 added was changed to 50 parts.
The volume average particle diameter D50v of the toner particles (A9) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, the content of the styrene copolymer (Joncrill 450) contained in the toner particles (A9) was measured in the same manner as in the toner particles (A1), and it was 4.2% by weight.

-Toner particles (A10)-
Toner particles (A1) were prepared in the same manner except that Joncrill 852 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 82 mgKOH / g, weight average molecular weight (Mw) 420,000) was used in the production of toner particles (A1). Particles (A11) were produced.
The volume average particle size D50v of the toner particles (A10) is 6.52 μm, the number average particle size distribution index GSDp is 1.23, and the volume average particle size distribution index GSDv is 1.22. Further, the shape factor SF1 of the toner particles was 132.
Further, when the content of the styrene copolymer (Johncrill 852) contained in the toner particles (A10) was measured in the same manner as in the toner particles (A1), it was 0.8% by weight.

-Toner particles (A11)-
Toner particles (A11) were prepared in the same manner as in the preparation of toner particles (A1) except that Joncrill 450 was not included.
The volume average particle diameter D50v of the toner particles (A11) is 6.5 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.23. Further, the shape factor SF1 of the toner particles was 129.

<Preparation of developer>
To 50 parts of the toner particles, 2.5 parts of hydrophobic silica (TS720, manufactured by Cabot) was added as an external additive, and blended in a sample mill to obtain each toner subjected to external addition treatment.
On the other hand, 11 parts of toluene, 2 parts of diethylaminoethyl methacrylate-styrene-methyl methacrylate copolymer (copolymerization ratio: 2/20/78, weight average molecular weight: 50,000), carbon black (manufactured by Cabot Corporation, R330R) 0. Two parts and glass beads (particle size: 1 mm, the same amount as toluene) were put into a sand mill manufactured by Kansai Paint Co., Ltd., and stirred at a rotational speed of 1200 rpm for 30 minutes to prepare a coating resin layer forming solution.

Next, 100 parts of this coating resin layer forming solution and Mn—Mg ferrite particles (true specific gravity: 4.6 g / cm ³ , volume average particle size: 35 μm, saturation magnetization: 65 emu / g) are vacuum degassed kneader. The mixture was stirred for 10 minutes while maintaining the temperature at 60 ° C., and then the pressure was reduced and toluene was distilled off to obtain a ferrite carrier having a coating resin layer formed thereon.
To this ferrite carrier, the toner is mixed so that the toner concentration becomes 5%, stirred and mixed for 5 minutes by a ball mill, and the developers (A1) to (A1) to (A1) to (A11) each containing the toner particles (A1) to (A11) A11) was prepared.

<Example A1>
Using the developer A1 described above, a Fuji Xerox printer DocuCenter Color 400CP remodeling machine is used as an image forming apparatus, and an evaluation image is processed at a process speed of 150 mm in an environment of high temperature and high humidity (28 ° C., 85% RH). / Sec and a fixing roll temperature of 150 ° C., 3000 sheet image formation processing was performed, and evaluation was performed according to the following criteria.
In the image formation, C2 paper (manufactured by Fuji Xerox Co., Ltd.) was used as paper.
Further, as the evaluation image, an image obtained by outputting a solid image of 25 mm × 25 mm on an A4 size paper is used.

-Evaluation of chargeability under high temperature and high humidity-
When ΔTP = (charge amount after 3000 sheets × toner concentration after 3000 sheets) / (initial charge amount × initial toner density), the determination was made according to the following criteria.
In the above formula, ΔTP indicates chargeability. In the above formula, the toner charge amount was measured by collecting the toner on the sleeve of the developing machine and using the blow-off method (measuring device: TB200, manufactured by Toshiba Chemical Corporation). Further, the toner concentration in the above formula indicates the weight ratio of the toner in the developer whose charging characteristics were measured.
A: ΔTP is 0.65 or more and less than 1.2 ○: ΔTP is 0.5 or more and less than 0.65 Δ: ΔTP is less than 0.5

-Low temperature fixability-
The low temperature fixability was evaluated as follows. Using a modified DocuCenter Color 400CP printer manufactured by Fuji Xerox Co., Ltd., with the fixing machine removed, the toner applied amount is adjusted to 10.5 g / m ² to produce an evaluation image, so-called image output. Obtained.
Next, fixing was performed at intervals of 5 ° C. within a range of 90 ° C. to 160 ° C. using a belt nip type external fixing device, and the minimum fixing temperature of the image was evaluated according to the following criteria. The minimum fixing temperature is a case where an unfixed solid image (25 mm × 25 mm) is fixed and then bent using a weight with a constant load. Sensory evaluation was made as a fixed one.
A: Fixable at 110 ° C. or lower ○ Fixable at 110-135 ° C. Δ: Fixable temperature 140 ° C. or higher

-Transferability-
Transferability was determined on the basis of the following criteria by measuring the weight of the untransferred sample remaining on the photoconductor every 500 sheets (initial stage) and every 1000 sheets thereafter. The “untransferred sample” refers to toner remaining on the photosensitive member without being transferred to the intermediate transfer member or paper, among the toner images developed on the photosensitive member. Before the untransferred sample was removed by the photoconductor cleaning device, the rotation of the photoconductor was forcibly stopped, transferred to a mending tape, and the weight was measured.
○: Good (when the untransferred sample is 10% by weight or less of the entire transferred sample)
(Triangle | delta): The untransferred sample is 1000 to 20 weight% of the whole transfer sample after 1000 sheets.
X: The untransferred sample is 20% by weight or more of the entire transferred sample in the initial stage (less than 1000 sheets).

-Filming evaluation-
The presence or absence of filming on the photoreceptor after the 3000-sheet image forming process was visually observed using a 50 × magnifying glass and evaluated according to the following criteria.
◎: Not confirmed ○: Confirmed with a loupe, but no effect on the image Δ: Although there is an effect on the image, there is no practical problem ×: The effect on the image is observed, and there is a practical problem.
The above evaluation results are shown in Table 1.

<Example A2 to Example A6, Comparative Example A1 to Comparative Example A5>
Example A2 to Example A6 and Comparative Example A1 to Comparative Example A5 were carried out using the developer (A2) to developer (A11) prepared above instead of the developer (A1) in Example A1. The actual machine evaluation similar to Example A1 was performed.
The evaluation results are shown in Table 1.

  As shown in Example A1 to Example A6 shown in Table 1, when the developer containing the toner of the present invention of Example is used, charging property under high temperature and high humidity, low temperature fixing property, transfer It can be seen that good results are obtained in all of the properties and filming properties.

  On the other hand, with the developers used in Comparative Examples A1 to A5, some problem occurred in any of charging property under high temperature and high humidity, low temperature fixing property, transfer property, and filming property.

<Preparation of toner containing 0.01% by weight or more and 1% by weight or less of styrene copolymer>

(Production of toner particles)
-Toner particles (B1)-
-Crystalline polyester resin dispersion (1) 240 parts-Amorphous polyester resin dispersion (1) 180 parts-Colorant dispersion 42 parts-Release agent particle dispersion 62 parts-Ion exchange water 350 parts In a stainless steel flask, adjusted to pH 2.7, and mixed and dispersed for 5 minutes by a homogenizer (manufactured by IKA: Ultra Turrax T50).
Next, 0.27 parts by weight of polyaluminum chloride was added thereto, and the dispersing operation was continued for 5 minutes with the ultra turrax. Further, the flask was heated to 44 ° C. with stirring in an oil bath for heating, and held at 44 ° C. for 120 minutes, and then 120 parts by weight of the amorphous polyester resin dispersion (1) was gradually added thereto.

Next, 7.5 parts of the above Jonkrill 450 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 100 mgKOH / g, weight average molecular weight (Mw) 146000) was added.
Next, after adjusting the pH of the system to 8.0 with a 0.5 mol / L sodium hydroxide aqueous solution, the stainless steel flask was sealed and heated to 93 ° C. while continuing to stir using a magnetic seal. Held for hours.

  After holding for 3 hours (after completion of the reaction), the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This operation was further repeated 5 times, and when the filtrate had a pH of 7.00, an electric conductivity of 8.8 μS / cm, and a surface tension of 71.0 Nm, solid-liquid separation was performed by Nutsche suction filtration using No5A filter paper. Next, vacuum drying was continued for 12 hours to obtain toner particles (B1).

The volume average particle diameter D50v of the toner particles (B1) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. In addition, the toner particle shape factor SF1 obtained by shape observation with a Luzex image analyzer was 131.
Further, when the content of the styrene copolymer (Joncrill 450) contained in the toner particles (B1) was measured in the same manner as in the toner particles (A1), it was 0.8% by weight.

-Toner particles (B2)-
Toner particles (B1) were prepared in the same manner except that Jonkrill 632 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 82 mgKOH / g, weight average molecular weight (Mw) 120,000) was used instead of Jonkrill 450. Particles (B2) were produced.

The volume average particle diameter D50v of the toner particles (B2) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. In addition, the toner particle shape factor SF1 obtained by shape observation with a Luzex image analyzer was 131.
Further, when the content of the styrene copolymer (Joncrill 450) contained in the toner particles (B2) was measured in the same manner as in the toner particles (A1), it was 0.8% by weight.

-Toner particles (B3)-
PDX7630A instead of Joncrill 450 in the production of toner particles (B1)
Toner particles (B3) were produced in the same manner except that an acid value (AV200, weight average molecular weight (Mw) 225000) manufactured by Johnson Polymer Co. was used.

The volume average particle diameter D50v of the toner particles (B3) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer (Joncrill 450) contained in the toner particles (B3) was measured in the same manner as in the toner particles (A1), it was 0.7% by weight.

-Toner particles (B4)-
Toner particles (B1) were prepared in the same manner except that Jonkrill 7100 (manufactured by Johnson Polymer Co., Ltd., acid value (AV51 mgKOH / g, weight average molecular weight (Mw) 213000)) was used instead of Jonkrill 450. B4) was produced.

The volume average particle diameter D50v of the toner particles (B4) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, when the content of the styrene copolymer (Joncrill 7100) contained in the toner particles (B4) was measured in the same manner as in the toner particles (A1), it was 0.8% by weight.

-Toner particles (B5)-
Toner particles (B1) were prepared in the same manner except that styrene copolymer dispersion (3) (acid value (AV110 mgKOH / g, weight average molecular weight (Mw) 62000)) was used instead of Joncrill 450. (B5) was produced.

The volume average particle diameter D50v of the toner particles (B5) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles (B5) was 131.
Further, the content of the styrene copolymer contained in the toner particles (B5) was measured in the same manner as in the toner particles (A1), and it was 1.3% by weight.

-Toner particles (B6)-
Toner particles (B6) were prepared in the same manner as in the preparation of toner particles (B1) except that the amount of Joncryl 450 added was changed to 25 parts.

The volume average particle diameter D50v of the toner particles (B6) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. The shape factor SF1 of the toner particles was 131.
Further, the content of the styrene copolymer (Joncrill 450) contained in the toner particles (B6) was measured in the same manner as in the toner particles (A1), and it was 2.4% by weight.

-Toner particles (B7)-
Toner particles (B7) were prepared in the same manner as in the preparation of toner particles (B1) except that the amount of Joncryl 450 added was changed to 0 part.

  The volume average particle diameter D50v of the toner particles (B7) is 6.4 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.28. Further, the shape factor SF1 of the toner particles (B7) was 131.

-Toner particles (B8)-
Toner particles (B1) were prepared in the same manner except that Jonkrill 852 (manufactured by Johnson Polymer Co., Ltd., acid value (AV) 82 mgKOH / g, weight average molecular weight (Mw) 420,000) was used instead of Jonkrill 450. Particles (B10) were produced.
The volume average particle diameter D50v of the toner particles (B8) is 6.5 μm, the number average particle size distribution index GSDp is 1.25, and the volume average particle size distribution index GSDv is 1.22. The shape factor SF1 of the toner particles was 131.
Further, the content of the styrene copolymer (Joncrill 852) contained in the toner particles (B8) was measured in the same manner as in the toner particles (A1), and it was 0.7% by weight.

<Preparation of developer>
To 50 parts of the toner particles, 2.5 parts of hydrophobic silica (TS720, manufactured by Cabot) was added as an external additive, and blended in a sample mill to obtain each toner subjected to external addition treatment.
On the other hand, 11 parts of toluene, 2 parts of diethylaminoethyl methacrylate-styrene-methyl methacrylate copolymer (copolymerization ratio: 2/20/78, weight average molecular weight: 50,000), carbon black (manufactured by Cabot Corporation, R330R) 0. Two parts and glass beads (particle size: 1 mm, the same amount as toluene) were put into a sand mill manufactured by Kansai Paint Co., Ltd., and stirred at a rotational speed of 1200 rpm for 30 minutes to prepare a coating resin layer forming solution.

Next, 100 parts of this coating resin layer forming solution and Mn—Mg ferrite particles (true specific gravity: 4.6 g / cm ³ , volume average particle size: 35 μm, saturation magnetization: 65 emu / g) are vacuum degassed kneader. The mixture was stirred for 10 minutes while maintaining the temperature at 60 ° C., and then the pressure was reduced and toluene was distilled off to obtain a ferrite carrier having a coating resin layer formed thereon.
To this ferrite carrier, the toner is mixed so that the toner concentration becomes 5%, stirred and mixed for 5 minutes by a ball mill, and the developers (B1) to (B1) to (B1) to (B8), respectively. B8) was prepared.

<Example B1>
Using the developer B1 described above, a Fuji Xerox printer DocuCenter Color 400CP remodeling machine is used as an image forming apparatus, and an evaluation image is processed at a process speed of 150 mm in an environment of high temperature and high humidity (28 ° C., 85% RH). / 3000, and a fixing roll temperature of 150 ° C., 3000 sheet image forming processing was performed. Thereafter, the printer with the developer placed therein is left in this high-temperature and high-humidity environment for 72 hours, and then the evaluation image is further processed under the conditions of the process speed and the fixing roll temperature before being left in the high-temperature and high-humidity environment. Below, 1000 images were formed.
In the image formation, C2 paper (manufactured by Fuji Xerox Co., Ltd.) was used as paper.
Further, as the evaluation image, an image obtained by outputting a solid image of 25 mm × 25 mm on an A4 size paper is used.

-Evaluation of chargeability-
ΔTP1 = (charge amount after forming 3000 images × toner concentration after 3000 sheets) / (initial charge amount × initial toner concentration)
ΔTP2 = (initial charge amount after being left × initial toner concentration after being left) / (initial charge amount × initial toner concentration)
ΔTP3 = (charge amount after image formation after 1000 sheets × toner density after image formation after 1000 sheets) / (initial charge amount × initial toner density)
In the above formula, ΔTP1, ΔTP2, and ΔTP3 each indicate charging properties.
“Charge amount” in the above formula was measured by collecting the toner on the sleeve of the developing machine and using the blow-off method (measuring device: TB200, manufactured by Toshiba Chemical Corporation). In the above formula, “toner concentration” indicates the weight ratio of the toner in the developer whose charging characteristics were measured. Also, “initial” means
The figure shows a state within 200 sheets of image formation. “Left” indicates that the film is left for 72 hours in the high-temperature and high-humidity (28 ° C., 85% RH) environment after forming 3000 images under the above conditions. The evaluation criteria for chargeability are shown below.
A: ΔTP is 0.65 or more and less than 1.2 ○: ΔTP is 0.5 or more and less than 0.65 Δ: ΔTP is less than 0.5

Further, the low-temperature fixability and the filming property were evaluated in the same manner as in Example A1, and evaluated using the same evaluation criteria as in Example A1.
The above evaluation results are shown in Table 2.

<Example B2 to Example B3, Comparative Example B1 to Comparative Example B5>
In place of the developer (B1) in Example B1, each of the prepared developer (B2) to developer (B3) is used as Example B2 to Example B3, and the prepared developer (B4) to developer. Each of the agents (B8) was used as Comparative Examples B1 to B5, and the same evaluation as in Example B1 was performed.
The evaluation results are shown in Table 2.

As shown in Table 2, when the developer containing the toner of the present invention is used (Example B1 to Example B3), the charging property under high temperature and high humidity, the low temperature fixing property, and the filming property are shown. It turns out that the favorable result is obtained in all. Furthermore, it can be seen that good results have been obtained for the chargeability after being left in a high temperature and high humidity environment.
On the other hand, in the developers used in Comparative Examples B1 to B5, there are some in any of chargeability under high temperature and high humidity, chargeability after standing in a high temperature and high humidity environment, low temperature fixability, and filming property. There was a problem.

1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention.

Explanation of symbols

80 Electrophotographic Photoreceptor 82 Image Forming Device 84 Charging Device 86 Exposure Device 87 Cleaning Member 88 Development Device 89 Transfer Device 90 Fixing Device

Claims (11)

  An electrostatic latent image developing toner containing a binder resin, a colorant, and a release agent, wherein the weight average molecular weight (Mw) is in the range of 70000-300000 and the acid value (AV) is 70 mgKOH A toner for developing an electrostatic latent image, comprising less than 3% by weight of a styrene copolymer in the range of / g to 220 mgKOH / g.   2. The electrostatic latent image developing toner according to claim 1, wherein the styrene copolymer is contained in an amount of more than 1% by weight and less than 3% by weight.   3. The styrene copolymer has a weight average molecular weight (Mw) in the range of 100,000 to 250,000 and an acid value (AV) in the range of 70 mgKOH / g to 150 mgKOH / g. The electrostatic latent image developing toner according to 1.   The toner for developing an electrostatic latent image according to claim 1, wherein the toner contains 1% by weight or less of the styrene copolymer.   5. The styrene copolymer has a weight average molecular weight (Mw) in the range of 70,000 to 300,000 and an acid value (AV) in the range of 70 mgKOH / g to 220 mgKOH / g. The electrostatic latent image developing toner according to 1. A method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 5,
The binder resin contains a first binder resin and a second binder resin, and a first resin fine particle dispersion obtained by dispersing first resin fine particles containing the first binder resin; In the mixed dispersion obtained by mixing the colorant dispersion obtained by dispersing the colorant and the release agent fine particle dispersion obtained by dispersing the release agent fine particles comprising the release agent, at least the first A first aggregating step for forming first agglomerated particles including resin fine particles, the colorant, and the release agent;
A second agglomeration step of forming second agglomerated particles by adhering second resin fine particles containing the second binder resin to the surface of the first agglomerated particles;
A stop step of stopping the growth of the second aggregated particles by adjusting the pH of the mixed dispersion that has undergone the second aggregation step;
The mixed dispersion liquid containing the second aggregated particles whose growth has been stopped by the stopping step is heated to a temperature equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. A unified process of uniting,
Have
In any one of the first aggregation step, the second aggregation step, the stopping step, and the fusion and coalescence step, a styrene copolymer containing the styrene copolymer in the mixed dispersion liquid A method for producing a toner for developing an electrostatic latent image, comprising adding a combined dispersion. A method for producing a toner for developing an electrostatic latent image according to claim 2, wherein:
The binder resin contains a first binder resin and a second binder resin, and a first resin fine particle dispersion obtained by dispersing first resin fine particles containing the first binder resin; A colorant dispersion obtained by dispersing the colorant, a release agent fine particle dispersion in which release agent fine particles comprising the release agent are dispersed, and a styrene copolymer dispersion containing the styrene copolymer, A first agglomeration step for forming first agglomerated particles containing at least the first resin fine particles, the colorant, the styrene copolymer, and the release agent in a mixed dispersion liquid.
A second agglomeration step of forming second agglomerated particles by adhering second resin fine particles containing the second binder resin to the surface of the first agglomerated particles;
A stop step of stopping the growth of the second aggregated particles by adjusting the pH of the mixed dispersion that has undergone the second aggregation step;
The mixed dispersion liquid containing the second aggregated particles whose growth has been stopped by the stopping step is heated to a temperature equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. A unified process of uniting,
A method for producing a toner for developing an electrostatic latent image, comprising: A method for producing a toner for developing an electrostatic latent image according to claim 4 or 5,
The binder resin contains a first binder resin and a second binder resin, and a first resin fine particle dispersion obtained by dispersing first resin fine particles containing the first binder resin; In the mixed dispersion obtained by mixing the colorant dispersion obtained by dispersing the colorant and the release agent fine particle dispersion obtained by dispersing the release agent fine particles comprising the release agent, at least the first A first aggregating step for forming first agglomerated particles including resin fine particles, the colorant, and the release agent;
An addition step of adding a styrene copolymer dispersion containing the styrene copolymer to the mixed dispersion subjected to the second aggregation step;
A stop step of stopping the growth of the second aggregated particles by adjusting the pH of the mixed dispersion that has undergone the addition step;
The mixed dispersion liquid containing the second aggregated particles whose growth has been stopped by the stopping step is heated to a temperature equal to or higher than the glass transition point of the first resin fine particles or the second resin fine particles. A unified process of uniting,
Have
In any one of the first aggregation step, the second aggregation step, the stopping step, and the fusion and coalescence step, a styrene copolymer containing the styrene copolymer in the mixed dispersion liquid A method for producing a toner for developing an electrostatic latent image, comprising adding a combined dispersion.   An electrostatic latent image developer comprising the electrostatic latent image developing toner according to claim 1. A charging step for charging the surface of the image carrier;
A developing step of developing a latent image corresponding to image information on the surface of the charged image carrier with an electrostatic latent image developer containing at least an electrostatic latent image developing toner to obtain a toner image;
A transfer step of transferring a toner image on the image carrier to a recording medium;
A fixing step of fixing the toner image on a recording medium;
In an image forming method including at least
The image forming method according to claim 1, wherein the electrostatic latent image developing toner is the electrostatic latent image developing toner according to claim 1. Charging means for charging the surface of the image carrier;
Developing means for developing a toner image by developing an electrostatic latent image corresponding to image information on the surface of the image carrier charged by the charging means with an electrostatic latent image developer containing at least toner for developing an electrostatic latent image. When,
Transfer means for transferring a toner image on the image carrier to a recording medium;
Fixing means for fixing the toner image on a recording medium;
An image forming apparatus comprising:
The image forming apparatus according to claim 1, wherein the electrostatic latent image developing toner is the electrostatic latent image developing toner according to claim 1.

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