JP2011215180A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner satisfying high speed, high image quality, high durability, low environmental load, coping with various kinds of media, and high environmental stability.SOLUTION: The toner includes: toner particles containing a binder resin, a colorant, a styrene resin containing a carboxyl group and polyester resin; and an inorganic fine powder; wherein the toner particles are manufactured in an aqueous medium, when the acid value of the styrene resin is A (mgKOH/g) and the acid value of methanol soluble component of the styrene resin is B (mgKOH/g), the relations, 50≤B≤110 and 2.0≤B/A≤10, are satisfied, and the weight average molecular weight of the styrene resin is 10,000-30,000, and when the acid value of methanol soluble component of the polyester resin is C (mgKOH/g), the relation, 1.1≤C/B≤3.0, is satisfied; the content of the styrene resin is 8-30 pts.mass; and the content of polyester resin is 1-10 pts.mass per 100 pts.mass of binder resin.

Description

  The present invention relates to a toner for use in an image forming apparatus such as an electrophotographic system or an electrostatic recording system for visualizing a developer by attaching a developer to a latent image formed on an image carrier. is there.

  Recent copiers and printers are becoming increasingly demanding in terms of size reduction, weight reduction and high reliability, and demands on toner performance are becoming strict. For example, there is a need for a toner having excellent durability that is less susceptible to filming on a photoreceptor and contamination of the surface of a toner carrier such as a carrier or a sleeve without impairing low-temperature fixability and offset resistance.

  In order to achieve such a demand, many proposals have been made that define the physical properties of the toner, particularly the molecular weight.

  There have been proposed toners in which the amount of components soluble in several types of solvents, the molecular weight, the acid value, and the like are defined (see, for example, Patent Document 1). However, there is room for improvement with regard to extremely low molecular weight components, and further improvement is required under more severe environmental conditions.

  In addition, a toner in which the amount of a low molecular weight component is defined has been proposed (see, for example, Patent Document 2). However, the effect of the best mode was not clearly shown and the effect was unclear. Further improvements are required in harsh environments and severe electrophotographic conditions.

  Further, a toner obtained by a suspension polymerization method in which the molecular weight distribution has a plurality of peaks and the peak position of the minimum molecular weight is 50,000 or less and the peak position of the maximum molecular weight is 200,000 or more has been proposed ( For example, see Patent Document 3). However, further improvement is currently required from the viewpoint of low-temperature fixability.

  On the other hand, GPC has a peak Mp1 in a molecular weight region of 500 to 2,000, a peak Mp2 in a molecular weight region of 10,000 to 100,000, and a weight average molecular weight (Mw) of 10,000 to 80. A color toner having a number average molecular weight (Mn) of 1,500 to 8,000 and a Mw / Mn ratio of 3 or more has been proposed (for example, see Patent Document 4). In this case, a color toner that is excellent in offset resistance and has a high saturation and a clear color image can be obtained. However, it has become necessary to develop a toner that is less likely to contaminate the surface of a toner carrier such as a carrier or a sleeve, and filming on a photoreceptor without impairing the low-temperature fixability.

  As described above, there is no toner that can solve various problems.

JP 2000-56511 A JP 2004-226670 A Japanese Patent Laid-Open No. 3-251853 JP-A-3-39971

  An object of the present invention is to provide a toner satisfying high speed, high image quality, high durability, and high environmental stability in view of the above situation.

The above object is achieved by the present invention described below. That is, a toner having toner particles and inorganic fine powder containing at least a binder resin, a colorant, a styrene resin containing a carboxyl group, and a polyester resin, and the toner particles are produced in an aqueous medium. Yes,
When the acid value of the carboxyl group-containing styrene resin is A (mg KOH / g) and the acid value of the methanol-soluble component of the carboxyl group-containing styrene resin is B (mg KOH / g),
50 ≦ B ≦ 110 and 2.0 ≦ B / A ≦ 10
And the weight average molecular weight (Mw) of the styrene-based resin containing the carboxyl group is 10,000 to 30000,
When the acid value of the methanol-soluble component of the polyester resin is C (mg KOH / g),
1.1 ≦ C / B ≦ 3.0
The content of the styrene-based resin containing a carboxyl group with respect to 100 parts by mass of the binder resin is 8 to 30 parts by mass, and the content of the polyester resin with respect to 100 parts by mass of the binder resin is 1 to 10 parts by mass. By being part by mass, the present invention is achieved.

  According to the present invention, a toner excellent in suppressing toner deterioration and member contamination can be obtained. In addition, a toner having excellent development stability, transferability, and fixability can be obtained. In addition, according to the present invention, excellent storability and developability can be obtained even in a situation where it is left for a long time in a high temperature and high humidity environment.

  Furthermore, according to the present invention, a toner having good dispersibility of the colorant can be obtained. In addition, according to the present invention, excellent developability can be obtained even in a situation where the process speed is high and the toner is loaded.

It is explanatory drawing of an example of the image development apparatus of this invention. It is explanatory drawing of an example of the image forming apparatus using the developing device of this invention.

In the present invention, first, the acid value of a styrene resin containing a carboxyl group is A (mg KOH / g), and the acid value of a methanol-soluble component of the carboxyl group-containing styrene resin is B (mg KOH / g). When
50 ≦ B ≦ 110 and 2.0 ≦ B / A ≦ 10
It is necessary to be.

  The resin component used in the toner includes a binder resin as a main component and a resin component having a polar group. In the present invention, the design of the polar resin component is particularly important. This is because the polar resin is greatly involved in charging characteristics and the toner surface characteristics are easily changed by the polar resin in toner production by the chemical method.

  The acid value A of the polar resin (in the present invention, a styrene resin containing a carboxyl group) in the toner indicates the affinity of the resin component to water. Furthermore, the acid value B of the methanol-soluble component of the polar resin shows affinity for the polar component of the low-molecular component in the resin.

  When the acid value B is 50 ≦ B ≦ 110, the dispersion can be improved by interacting with polar groups such as a charge control agent and a colorant. Further, in toner production by chemical method, the toner particles are kept stable, a sharp particle size distribution is achieved, and good chargeability is exhibited. When the acid value B is less than 50, the dispersion of the charge control agent, the colorant and the like tends to deteriorate. As a result, non-uniform charge amount occurs, and electrophotographic characteristics such as fog are likely to deteriorate. When the acid value B exceeds 110, for example, when left for a long time under high temperature and high humidity conditions, the surface state of the toner changes and the electrophotographic characteristics (charge amount, fog, etc.) tend to deteriorate.

  The ratio of acid value A to acid value B, B / A, indicates the affinity of the resin component to water. In the present invention, the acid value ratio B / A needs to be in the range of 2.0 to 10. If B / A is less than 2.0, the affinity of the resin for water is too low, rapid chargeability is unlikely to occur, and durability stability is lost. When B / A exceeds 10, the affinity of the resin to water is too high, and the electrophotographic characteristics (charge amount, fog, etc.) tend to deteriorate when left for a long time under high temperature and high humidity conditions.

  Next, in the present invention, the weight average molecular weight (Mw) of the styrene resin containing the carboxyl group needs to be 10,000 to 30,000.

  When the weight average molecular weight (Mw) is 10,000 to 30,000, it interacts with a polar group such as a charge control agent or a colorant to improve the dispersion, thereby mixing with other resin or other material in the toner. Good dispersibility. Furthermore, in toner production by a chemical method, the dispersibility and solubility in a solution are good, the toner particles are kept stable, a sharp particle size distribution is achieved, and good chargeability is exhibited.

  When the weight average molecular weight (Mw) of the styrene resin containing a carboxyl group is less than 10,000, although dispersibility is good, bleeding of various materials at high temperature and high humidity after the toner is produced is not preferable. . On the other hand, when the weight average molecular weight (Mw) of the styrene-based resin containing the carboxyl group exceeds 30000, the miscibility with other resins and other materials in the toner is deteriorated and the dispersibility tends to be lowered. As a result, non-uniform charge amount occurs, and electrophotographic characteristics such as fog are likely to deteriorate. In addition, the low-temperature fixability tends to deteriorate.

<Method for measuring molecular weight distribution of toner>
A sample for GPC measurement is prepared as follows.

  The toner is put in a THF (tetrahydrofuran) solvent and allowed to stand for several hours. Then, the toner is mixed well with shaking and allowed to stand for 12 hours or more. At this time, the standing time is set to 24 hours or more.

  Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corporation, Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used, A sample of GPC is used. The resin concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

The molecular weight and molecular weight distribution by GPC of the THF soluble component of the binder resin were stabilized in a 40 ° C. heat chamber measured by the following method, and 1 ml of THF as a solvent was added to the column at this temperature per minute. Flow at a flow rate and measure by injecting about 100 μl of THF sample solution. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ^{2 to} 10 ⁷ manufactured by Tosoh Corporation or Showa Denko Corporation, and at least about 10 standard polystyrene samples are suitably used. . An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, a combination of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko, TSKge1G1000H (H _XL ), G2000H (H _XL ), G3000H (H _XL ), G4000H (H _XL ), G5000H (H _XL ), G6000H (H _XL ), G7000H (H _XL ) A combination of TSKguardcolumns. In particular, the column structure is preferably a combination of A-801, 802, 803, 804, 805, 806 and 807 manufactured by Showa Denko KK.

  Further, when the acid value of the methanol-soluble component of the polyester resin is C (mg KOH / g) and 1.1 ≦ C / B ≦ 3.0, the development characteristics (charge amount, fog, etc.) are good. And there is little deterioration even in long-term durability. Furthermore, it has excellent fixing characteristics.

  When C / B ≦ 1.1, Mw1 is too small, transferability is deteriorated, and fog tends to increase in developability.

  When 3.0 ≦ C / B, Mw1 is too large or Mw2 is too small. When Mw1 is too large, toner breakage tends to occur, and when Mw2 is too small, transferability is deteriorated. However, fog tends to increase in developability.

  It is necessary that the content of the styrene resin containing a carboxyl group with respect to 100 parts by mass of the binder resin is 8 parts by mass to 30 parts by mass. When the content is within this range, it becomes an optimum addition amount for interacting with polar groups such as a charge control agent and a colorant to improve dispersion. The said effect will become inadequate that the content is less than 8 mass parts. When the content exceeds 30 parts by mass, it is not preferable because segregation of materials such as a charge control agent and a colorant is caused.

  On the other hand, the content of the polyester resin with respect to 100 parts by mass of the binder resin needs to be 1 part by mass to 10 parts by mass. When the content is within this range, the charge control agent, the colorant and the like are excellently dispersed, and at the same time, the addition amount is optimal for enhancing the storage stability of the toner at a high temperature. In toner production by a chemical method, the dispersibility and solubility in a solution are good, the toner particles are kept stable, a sharp particle size distribution is achieved, and good chargeability is exhibited. The said effect becomes inadequate that the content is less than 1 mass part. When the content exceeds 10 parts by mass, it is not preferable because segregation of materials such as a charge control agent and a colorant is caused. In addition, the particle size distribution tends to be deteriorated in toner production by a chemical method.

  In the present invention, in addition to the essential items described above, satisfying the items as described below provides a more preferable form and increases the effect.

  The methanol-soluble component in the styrene resin containing a carboxyl group in the toner is a component having a high polar group, and it is important to control this component. When the methanol-soluble component is controlled to 0.05 to 1.0% by mass, the development characteristics (charge amount, fog, etc.) are good, and there is little deterioration in long-term durability. Furthermore, it has excellent storage characteristics when left at high temperature. In addition, since the styrenic resin interacts with polar groups such as a charge control agent and a colorant to improve dispersion, it is important to contain an appropriate amount of a methanol-soluble component containing a large amount of polar groups.

  When the methanol-soluble component is less than 0.05% by mass, the surface is not flexible and the toner is crushed due to long-term durability and the like, and the member is likely to be fused. Also, the storage stability at high temperatures is not satisfactory. Furthermore, it is difficult to satisfy the dispersion of charge control agents and colorants. When the methanol-soluble component exceeds 1.0% by mass, the hygroscopicity becomes too high, the transferability is deteriorated, and the fog is increased in the developability.

  Here, the measuring method of the soluble part with respect to a methanol solvent is shown below.

<Method for extracting and measuring methanol-soluble matter>
The methanol-soluble component in the present invention refers to the mass ratio of the medium high molecular weight polymer component present near the toner surface layer that is soluble in the methanol solvent in the resin composition in the toner. The soluble content is defined as a value measured as follows.

  A toner sample (1.0 g) is weighed, and 60 ml of methanol is used as a solvent to extract by stirring at room temperature (20 ° C.) for 12 hours. After evaporating soluble components extracted with the mixed solvent, vacuum is applied at 100 ° C. for several hours. After drying, the mixed solvent-soluble resin component amount is weighed.

  Further, in the polyester resin in the toner, the methanol-soluble component is a component having high water affinity, and it is important to control this component. When the methanol-soluble component is controlled to 0.2 to 1.2% by mass, charging is performed using water as a medium, development characteristics (charge amount, fog, etc.) are good, and deterioration is small even in long-term durability. Furthermore, it is excellent in low-temperature fixing characteristics. In addition, the polyester resin has an effect of keeping particles stably at the interface with water in a chemical toner, and it is important to contain an appropriate amount of a methanol-soluble component containing a large amount of polar groups.

  When the methanol-soluble component is less than 0.2% by mass, the surface becomes inflexible and the toner is crushed due to long-term durability and the like, and the member is likely to be fused. In addition, the fixing property, particularly in a fixing device having a low pressure, is not satisfactory in the low temperature fixing property. In addition, it is difficult to satisfy the particle stability during production of chemical toners. When the methanol-soluble component exceeds 1.2% by mass, the hygroscopicity becomes too high, the transferability is deteriorated, and the fog is increased in the developability.

  In the styrene resin containing a carboxyl group in the toner, the cyclohexane insoluble component is a component having a low water affinity and a component having a relatively high molecular weight. It is important to control this component. When the cyclohexane insoluble component is controlled to 0.5% by mass or less, the flexibility of the toner increases, the development characteristics (charge amount, fog, etc.) are good even in a situation where the process speed is high, and the deterioration is small even in the long-term durability. . Furthermore, since there are few polymer components, the fixing property is excellent and there is an image with high glossiness.

  If the cyclohexane insoluble component exceeds 0.5% by mass, the fixing characteristics are likely to deteriorate. Further, since the molecular weight is high, uniform dispersion in the toner is not sufficient, and thus fogging or the like is likely to occur due to a decrease in coloring power or non-uniform charging.

  Here, a method for measuring an insoluble content in a cyclohexane solvent is shown below.

<Method for measuring cyclohexane insoluble matter>
The cyclohexane insoluble matter in the present invention indicates the mass ratio of the high molecular weight polymer component that has become insoluble in the cyclohexane solvent in the resin composition. The insoluble matter is defined as a value measured as follows.

  A toner sample (1.0 g) is weighed, and 60 ml of cyclohexane as a solvent is stirred and extracted at room temperature (20 ° C.) for 12 hours. Soluble components extracted with the mixed solvent are evaporated, and then vacuumed at 100 ° C. for several hours. After drying, the mixed solvent soluble resin component amount is weighed and calculated from the amount subtracted from the original amount.

  In the present invention, the methanol wettability half value (H20) of the toner base particles when left at 20 ° C. is preferably 15 <H20 <30. When the methanol wettability half-value is 15% or less, the abundance of the methanol-soluble substance on the toner surface is low and the low-temperature fixability is not satisfactory. When the content is 30% or more, the amount of methanol-soluble substance on the toner surface is large and the low-temperature fixability is good. However, when the fixing temperature is high, the resin and the methanol-soluble substance are separated. Is not preferable because sufficient hot offset resistance cannot be exhibited.

  Here, the toner base particles mean colored particles before the external addition processing of fine particles. In addition, the methanol wettability half-value refers to the point at which the transmittance is measured by methanol titration used when measuring the degree of methanol hydrophobization, and the point at which the sample is completely sunk, that is, the point at which the transmittance is minimized (the degree of methanol hydrophobization is The point is defined as the methanol concentration (methanol used volume%) at the time when the transmittance reaches the middle of the transmittance before the sample addition (50% transmission). .

  In the present invention, the methanol wettability half value is determined as follows.

[Measurement of methanol wettability half-value]
Weigh out 60 cm ³ of ion exchange water into a 200 cm ³ beaker. 0.0100 g of a sample is placed in a methanol aqueous solution, and the transmittance is measured using a powder wettability tester “WET-100P” (manufactured by Reska Co., Ltd.). For the transmittance measurement, a semiconductor laser having an output of 3 mW and a wavelength of 780 nm was used. Measurement conditions are a stirrer rotation speed: 5 sec ⁻¹ and a methanol flow rate: 0.8 cm ³ / min. When the transmittance before addition of the sample is I ₀ (100%), the transmittance at the time of measurement is I (%), and the minimum measured transmittance is I _min (%), the methanol wettability half-value is the transmittance I Is I = 100 − {(I ₀ −I _min ) / 2} (%)
This is expressed as the volume% of methanol used.
Methanol wettability half value (%) = {[methanol titration (cm ³ )] / [methanol titration + 60.0 (cm ³ )]} × 100.

Here, the volume% of methanol used at the transmittance I _min has the same meaning as the degree of hydrophobicity of methanol, and this point is defined as the end point of methanol wettability.
Methanol wettability end point (%) = {[total amount of methanol used up to the lowest transmittance (cm ³ )]} / [total amount of methanol used up to the lowest transmittance +60.0 (cm ³ )]} × 100

  In the present invention, it is preferable that H50 is 26 <H50 <45 when the methanol wettability half-value of the toner base particles when left at 50 ° C. for 12 hours is H50. When the methanol wettability half-value is 26% or less, the abundance of methanol-soluble substances on the toner surface is low, and the low-temperature fixability is not satisfactory. In the case of 45% or more, when stored at 50 ° C., it indicates that a large amount of methanol-soluble substance has migrated to the toner surface, and the low-temperature fixability is good. It is not preferable because it shows a tendency to deteriorate the property and transferability.

  Further, in the present invention, when the methanol wettability half-value of the toner base particles when left at 40 ° C. for 12 hours is H40, and the methanol wettability half-value of the toner base particles after standing at 50 ° C. for 12 hours is H50, H20 <H40 < Preferably, H50, and 5 <(H50−H40) <15. When the methanol wettability half-value is 5% or less, the abundance of methanol-soluble substances on the toner surface is low, the thermal response of the surface is poor, and when the process speed increases, the low-temperature fixability cannot be satisfied. Come. On the other hand, when the content is 15% or more, the amount of methanol-soluble substance on the toner surface is large and the low-temperature fixability is good, but the thermal response of the surface is too high. In addition, the transferability tends to deteriorate, which is not preferable.

  In the toner of the present invention, the cyclohexane-soluble component is a component having a medium molecular weight and low water affinity, and it is important to control this component. When the cyclohexane-soluble component is controlled to 60 to 100% by mass, the development characteristics (charge amount, fog, etc.) are not deteriorated and the fixing characteristics are also excellent. In particular, it is possible to achieve a high gloss image required for a pictorial image. If the cyclohexane-soluble component is less than 60% by mass, the development characteristics are good, but it is difficult to achieve a high gloss image required for pictorial images.

  Here, the method for measuring the soluble content of the toner in the cyclohexane solvent is shown below.

<Method for measuring cyclohexane-soluble matter>
The cyclohexane-soluble component in the present invention refers to the weight ratio of the medium high molecular weight polymer component present in the toner that has become soluble in the cyclohexane solvent in the resin composition in the toner. The soluble content is defined as a value measured as follows.

  A toner sample (1.0 g) is weighed, and 60 ml of cyclohexane as a solvent is stirred and extracted at room temperature (20 ° C.) for 12 hours. Soluble components extracted with the mixed solvent are evaporated, and then vacuumed at 100 ° C. for several hours. After drying, the mixed solvent-soluble resin component amount is weighed.

  The toner of the present invention preferably has a melt viscosity at 100 ° C. of 5000 to 30000. This is because it is difficult to judge the behavior of the toner, which is a composite of various functional substances, based only on the physical properties and addition amount of the material substance, and the gel content (insoluble content) and non-gel content of the binder resin ( It is considered that it can be evaluated as a complex of a release agent) and a release agent.

  In the present invention, by setting the melt viscosity at 100 ° C. of the toner to 5,000 to 30,000, a full color image having stable color reproducibility and fixability can be obtained without impairing the durability stability during development. When the toner has a melt viscosity of less than 5,000, the durability stability during development deteriorates, and the fixability tends to be inferior to the high-temperature offset resistance. When the melt viscosity of the toner exceeds 30000, the fixability in a fixing device with a low applied pressure is inferior or the color mixture is insufficient and the color reproducibility is inferior.

  Here, a method for measuring the melt viscosity of the toner by flow tester measurement at 100 ° C. will be described below.

<Measurement of melt viscosity at 100 ° C.>
As an apparatus, for example, a flow tester CFT-500D (manufactured by Shimadzu Corporation) is used, and measurement is performed under the following conditions.
Sample: 1.0 g of toner is weighed and molded by pressing it with a pressure molding machine having a diameter of 1 cm at a load of 20 kN for 1 minute.
-Die hole diameter: 1.0mm
-Die length: 1.0mm
・ Cylinder pressure: 9.807 × 10 ⁵ (Pa)
Measurement mode: Temperature rising method Temperature rising rate: 4.0 ° C./min

  By the method described above, the viscosity (Pa · s) of the toner at 50 ° C. to 200 ° C. is measured to determine the melt viscosity (Pa · s) at 100 ° C.

  In the present invention, the average circularity of the toner is preferably 0.960 to 0.990.

  Here, the flow type particle image measuring apparatus is an apparatus that statistically performs image analysis of particle imaging, and the average circularity is calculated by the arithmetic average of the circularity obtained by the following equation using the apparatus.

  In the above equation, the perimeter of the particle projection image is the length of the contour line obtained by connecting the edge points of the binarized particle image, and the perimeter of the equivalent circle is the binarized particle This is the length of the outer circumference of a circle having the same area as the image. The equivalent circle diameter is the diameter of a circle having the same area as the area of the measured two-dimensional image of the particles.

  FPIA-2100 (manufactured by Sysmex Corporation) is used as a flow type particle image measuring apparatus. As a measuring method, 0.02 g of a measurement sample is added to 10 ml (20 ° C.) of a solution prepared by adding 0.1 to 0.5% by mass of a surfactant (preferably Wako Pure Chemicals Contaminone) to ion-exchanged water. To prepare a sample dispersion. As a means for dispersion, an ultrasonic disperser UM-50 manufactured by SMT Co., Ltd. (vibrator is a titanium alloy tip of 5φ) is used, and the dispersion time is set to 5 minutes, and the temperature of the dispersion medium does not exceed 40 ° C. Cooled to. In the measurement, the range of 0.60 to 400 μm is divided into 226 channels, and in the actual measurement, particles are measured in a range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

  When the average circularity is 0.960 to 0.990, the toner shape is almost spherical, so that there is little transfer residue, and a good result can be obtained with little load in charging in the roller and recovery in the cleaning unit. When the average circularity is less than 0.960, a large amount of toner remains after transfer, so that charging roller contamination and fusing in the cleaning portion are likely to occur.

  The method for producing the toner of the present invention is a method in which a toner is directly produced using a suspension polymerization method; toner particles are produced by direct polymerization in the presence of a water-soluble polymerization initiator that is soluble in a monomer. Examples thereof include production of toner particles by an emulsion polymerization method typified by a soap-free polymerization method. In addition, production of an interfacial polymerization method such as a microcapsule production method, an in situ polymerization method, a coacervation method, and the like can also be mentioned. Furthermore, an interfacial association method for aggregating at least one kind of fine particles to obtain a desired toner may be used. Alternatively, a method in which the toner obtained by the pulverization method is spheroidized by a mechanical impact force can be used.

  Among these, a suspension polymerization method that can easily obtain toner particles having a small particle diameter is particularly preferable. When suspension polymerization is used as a method for producing toner particles, the toner particles can be produced directly by the following production method.

  Adds a colorant, polymerization initiator, cross-linking agent, and other additives to the monomer, and contains a dispersion stabilizer that is uniformly dissolved or dispersed by a homogenizer, ultrasonic disperser, etc. Disperse in an aqueous medium using a normal stirrer, homomixer or homogenizer. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, usually 50 to 80 ° C. (preferably 55 to 70 ° C.). The temperature may be raised in the latter half of the polymerization reaction, and the pH may be changed as necessary. In the present invention, in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the aqueous medium is partially distilled off in the latter half of the reaction or after the completion of the reaction. May be. After completion of the reaction, the produced toner particles are collected by washing and filtration and dried.

  The following describes the material of the polymerization toner.

  As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer is mainly used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate , N-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more.

  In the present invention, a water-soluble initiator may be used in combination as an aid to the reaction. Examples include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloride, azobis (isobutyl) Amidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

  In order to control the degree of polymerization of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor or the like can be further added and used.

  Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, and barium sulfate. , Bentonite, silica, alumina, hydroxyapatite and the like. Usually, it is preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

  As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used. These dispersants are preferably used in an amount of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Other dispersion stabilizers preferably used include sparingly water-soluble metal salts of sulfuric acid, carbonic acid, phosphoric acid, pyrophosphoric acid, and polyphosphoric acid. These are acid alkali metal salts and metal halide salts under high-speed stirring in a dispersion medium. It is preferable to prepare by this reaction.

  In order to make these dispersants fine, 0.001 to 0.1% by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

  In the present invention, when a condensation compound is used, for example, polyester, polycarbonate, phenol resin, epoxy resin, polyamide, cellulose and the like can be mentioned. More preferably, polyester is desired due to the variety of materials.

  The colorant used in the present invention is carbon black or a known yellow / magenta / cyan colorant as shown below.

  As the yellow colorant, compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 151, 154, 155, 168, 180, 185, etc. are suitable. Used for.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48; 3, 48; 4, 57; 1, 81; 1, 122, 146, 166, 150, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.

  As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  Examples of the wax used in the present invention include paramethylene wax, polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer Tropish wax, amide wax, ketone wax, higher fatty acid, long chain alcohol, ester wax, and graft compounds thereof. And derivatives such as block compounds.

  Examples of the wax preferably used include linear alkyl alcohols having 15 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. Those from which impurities such as liquid fatty acids have been previously removed from these waxes are also preferred.

  Further, the wax preferably used is a low molecular weight alkylene polymer obtained by polymerizing alkylene with radical polymerization under high pressure or Ziegler catalyst or other catalyst under low pressure; alkylene obtained by thermally decomposing high molecular weight alkylene polymer Polymer: A low molecular weight alkylene polymer produced as a by-product in the polymerization of alkylene, separated and purified; a hydrocarbon polymer distillation residue obtained from a synthesis gas consisting of carbon monoxide and hydrogen by the age method, or a distillation residue And polymethylene wax obtained by extracting and fractionating specific components from a synthetic hydrocarbon obtained by hydrogenation. These waxes may contain an antioxidant.

  As the toner additive that can be used in the present invention, oil-treated inorganic fine powders such as silica and titania are preferably used. In addition to oxides such as zirconium oxide and magnesium oxide, silicon carbide, silicon nitride, boron nitride, aluminum nitride, magnesium carbonate, organosilicon compounds, and the like can be used in combination.

Silica is preferable in that the coalescence of the primary particles can be controlled arbitrarily to some extent depending on the starting material or the oxidation conditions such as temperature. For example, the silica can be either a so-called dry process produced by vapor phase oxidation of silicon halide or alkoxide, or a so-called wet silica produced from alkoxide, water glass, etc. However, dry silica is preferable because it has few silanol groups on the surface and inside of the silica fine powder and few production residues such as Na ₂ O and SO ₃ ²⁻ . In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Is also included.

  Furthermore, the silica is preferably hydrophobized in order to reduce the dependency of the toner charge amount on the environment, such as temperature and humidity, and to prevent excessive release from the toner surface. Examples of the hydrophobizing agent include coupling agents such as a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. In particular, the silane coupling agent reacts with residual groups on the inorganic oxide fine particles or adsorbed water to achieve a uniform treatment, which is preferable in terms of stabilizing charging of the toner and imparting fluidity.

The silane coupling agent has the following general formula RmSiYn
R: an alkoxy group m: an integer from 1 to 3 Y: an alkyl group, a hydrocarbon group including a vinyl group, a glycidoxy group, and a methacryl group, n: an integer from 1 to 3. For example, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethyl Examples include methoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

More preferably, C _a H _{2a + 1} —Si (OC _b H _{2b + 1} ) ₃
(A = 4 to 12, b = 1 to 3)
It is.

  Here, when a in the general formula is smaller than 4, the treatment becomes easy, but the hydrophobicity cannot be sufficiently achieved. On the other hand, if a is greater than 12, the hydrophobicity is sufficient, but the coalescence between the particles increases, and the fluidity imparting ability decreases.

  When b is larger than 3, the reactivity is lowered and the hydrophobicity is not sufficiently performed. Therefore, a in the above general formula is 4 to 12, preferably 4 to 8, and b is 1 to 3, preferably 1 to 2.

  With respect to the oil treatment of silica, untreated silica may be directly treated with oil, but it is more preferable from the viewpoint of charging stability that the hydrophobized silica is further treated with oil. As the oil, dimethylpolysiloxane, methylhydrogenpolysiloxane, paraffin, mineral oil and the like can be used, and among them, dimethylpolysiloxane excellent in environmental stability is preferable. The amount of oil used for the treatment is appropriately 2 to 40 parts by mass with respect to 100 parts by mass of the silica fine particle matrix.

  In the toner of the present invention, other additives such as a fluororesin powder, a zinc stearate powder, a polyvinylidene fluoride powder such as a lubricant powder; a cerium oxide powder, a silicon carbide powder, Develops abrasives such as strontium titanate powder, anti-caking agents such as aluminum oxide powder, or conductivity imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder, and organic and inorganic particles of opposite polarity A small amount can also be used as a property improver.

  Next, an image forming method of the present invention, an image forming apparatus that implements the method, and a process cartridge will be described.

  An image forming method to which the present invention can be applied will be described below with reference to the accompanying drawings.

(Non-magnetic one-component image forming device)
(1) Example of Image Forming Apparatus FIG. 2 is a schematic configuration diagram of an example of an image forming apparatus according to the present invention. The image forming apparatus of this example is a tandem type electrophotographic color (multicolor image) printer of a tandem type in which a plurality of image bearing members (latent image carriers) as photosensitive drums are arranged one above the other.

  PY, PM, PC, and PBk are first to fourth four image forming units (image forming units) that form toner images of yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Unit), which are arranged in the image forming apparatus main body in parallel from the bottom to the top.

  These first to fourth image forming units PY, PM, PC, and PBk have the same configuration and electrophotographic image forming function except that the colors of the toner images to be formed are different as described above. Yes. That is, each of the first to fourth image forming units includes a drum-type electrophotographic photosensitive member (photosensitive drum) 1 as a first image carrier and a charging roller 2 as a primary charging unit, as shown in FIG. , A laser irradiation device 3 as an exposure means, a toner development device 4 as a development means, a primary transfer roller 5 as a primary transfer means, a blade cleaning device 6 as a cleaning means, and the like. The developers accommodated in the toner developing devices 4 of the first to fourth image forming units are yellow toner, cyan toner, magenta toner, and black toner, respectively. Each color toner will be described later.

  The image forming apparatus according to the present exemplary embodiment includes four processes of the photosensitive drum 1, the charging roller 2, the developing device 4, and the blade cleaning device 6 in each of the first to fourth image forming units PY, PM, PC, and PBk. The apparatus is a process unit (process cartridge) that is detachable and replaceable with respect to the main body of the image forming apparatus.

  Reference numeral 13 denotes an endless belt-shaped intermediate transfer belt as a second image carrier, and the first to fourth image forming portions PY, PM, PC, and PBk on the photosensitive drum 1 side (printer front side). In FIG. 3, the four image forming units are arranged in the vertical direction by being suspended between a plurality of support rollers (not shown). In each of the first to fourth image forming units, the primary transfer roller 5 is brought into pressure contact with the photosensitive drum 1 via the intermediate transfer belt 13. A contact portion between each photosensitive drum 1 and the intermediate transfer belt 13 is a primary transfer portion.

  In each of the first to fourth image forming units PY, PM, PC, and PBk, each photosensitive drum 1 that is driven to rotate forward is charged by a charging roller 2 to which a charging bias is applied from a power circuit (not shown) during the rotation process. The primary charging is uniformly performed to a predetermined polarity and potential. Light image exposures LY, LM, LC, and LBk are performed by the LED array device 3 on the charged surface in accordance with image patterns of yellow, magenta, cyan, and black, which are color separation component images of full-color images, respectively. . Then, an electrostatic latent image of image information is formed on each photosensitive drum 1. Each of the electrostatic latent images is developed as a toner image by the developing device 4. Colors of yellow, magenta, cyan, and black, which are color separation component images of full-color images, are formed on the surfaces of the photosensitive drums 1 of the first to fourth image forming units PY, PM, PC, and PBk, respectively, by an electrophotographic process. A toner image is formed at a predetermined sequence control timing.

  Then, in each of the first to fourth image forming units PY, PM, PC, and PBk, the yellow, magenta, cyan, and black color toner images formed on the surface of each photosensitive drum 1 are the positive images of the respective photosensitive drums 1. The first to fourth image forming portions PY, PM, PC, and PBk with respect to the surface of the intermediate transfer belt 13 that is driven to rotate at the same speed as the photosensitive drum 1 in the clockwise direction of the forward arrow in the rotation direction. In the primary transfer portion, the images are sequentially superimposed and transferred to the primary transfer roller by a primary transfer bias applied from a power supply circuit (not shown). As a result, an unfixed full-color toner image (mirror image) is synthesized and formed on the surface of the intermediate transfer belt 13 that is rotationally driven.

  In each of the first to fourth image forming units PY, PM, PC, and PBk, the transfer residual toner remaining on each photosensitive drum 1 after the primary transfer of the toner image to the intermediate transfer belt 13 is performed by the cleaning blade of the blade cleaning device 6. It is removed and stored in the storage unit 6b in the device 6.

  Reference numeral 15 denotes a secondary transfer roller. The counter roller is disposed inside the intermediate transfer belt at the lower end side of the intermediate transfer belt 13, and the secondary transfer roller 15 sandwiches the intermediate transfer belt 13 between the counter roller and the outer surface of the intermediate transfer belt 13. It is made to contact | abut. A contact portion between the secondary transfer roller 15 and the intermediate transfer belt 13 is a secondary transfer portion.

  Reference numeral 20 denotes a paper feed cassette disposed in the lower part of the main body of the image forming apparatus, in which a transfer material as a final recording medium is stacked and accommodated. The conveying means (pickup roller) 14 is driven at a predetermined sequence control timing to separate and feed one sheet of the transfer material P in the paper feed cassette 20, and is fed to the secondary transfer section at a predetermined timing. The unfixed full-color toner image synthesized and formed on the intermediate transfer belt 13 is transferred onto the surface of the transfer material P by a secondary transfer bias applied from a power supply circuit (not shown) to the secondary transfer roller 15 in the secondary transfer portion. It will be batch-transcribed.

  The transfer material that has passed through the secondary transfer portion is separated from the surface of the intermediate transfer belt 13 and sent to the fixing device 7 by the transport belt 18.

  The transfer residual toner remaining on the intermediate transfer belt 13 is removed by the cleaning blade of the blade cleaning device 16 and sent to the waste toner box 17 to be stored.

  The unfixed full-color toner image on the transfer material sent to the fixing device 7 is melted and fixed to the transfer material by applying heat and pressure by the fixing device 7 and is disposed on the upper surface of the image forming apparatus main body through the sheet path. The sheet is discharged as a color image formed product onto the discharged paper discharge tray 19.

As the configuration of the intermediate transfer belt 13, PVDF having a thickness of 100 μm and a volume resistivity of 10 ¹⁰ Ωcm is used. As the secondary transfer counter roller, a roller having a diameter of 25, coated with EPDM rubber having a resistance of 10 ⁴ Ω and a thickness of 1.5 mm, in which carbon is dispersed as a conductive agent in an Al core metal, is used.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but this does not limit the present invention in any way. “Part” means “part by mass”.

[Synthesis of binder resin]
<Synthesis example 1 of styrenic polar resin>
As raw material and solvent,
Styrene monomer 95.6 parts n-butyl acrylate 1.0 part methacrylic acid 1.7 parts methyl methacrylate 1.7 parts xylene 100.0 parts equipped with thermometer, stirrer, reflux condenser and nitrogen gas inlet tube In a four-necked flask (four-neck flask), gradually heated with stirring and passing nitrogen gas through the four-necked flask, and at 100 ° C, 0.5% of perbutyl D (manufactured by NOF Corporation) was used as a polymerization initiator. A portion of the solution was added dropwise, and the temperature was raised to 200 ° C. and reacted for 5 hours.

After that, the temperature is lowered to 100 ° C.
Styrene monomer 9.6 parts n-butyl acrylate 0.1 part methacrylic acid 0.3 part methyl methacrylate 0.2 part is added, 0.1 part of additional initiator perbutyl D (manufactured by NOF Corporation) is added dropwise, The temperature was raised to 200 ° C. and reacted for 5 hours. The precursor styrene-type polar resin 1 which is a styrene-methacrylic acid-methyl methacrylate copolymer was obtained.

  Thereafter, the precursor styrene polar resin 1 was washed with a solvent of water / methanol = 60: 40 to obtain a styrene polar resin 1. This styrene meter polar resin 1 has Mp = 12000, Mw = 15000, Tg = 92 ° C., acid value A = 15.0 mgKOH / g, acid value B = 76.0 mgKOH / g.

<Synthesis Example 2 of Styrenic Polar Resin>
In Synthesis Example 1 of the styrenic polar resin, the same procedure was performed except that the addition amount of the initiator was changed from 0.5 part to 0.45 part, and the additional initiator was changed from 0.1 part to 0.09 part. A styrene polar resin 2 which is a methacrylic acid-methyl methacrylate copolymer was obtained. This styrene meter polar resin 2 has Mp = 14000, Mw = 19000, Tg = 93 ° C., acid value A = 14.5 mgKOH / g, acid value B = 80.0 mgKOH / g.

<Synthesis Example 3 of Styrenic Polar Resin>
In Synthesis Example 1 of the styrenic polar resin, the same procedure was performed except that the addition amount of the initiator was changed from 0.5 part to 0.65 part and the additional initiator was changed from 0.1 part to 0.12 part. A styrene polar resin 3 which is a methacrylic acid-methyl methacrylate copolymer was obtained. This styrene meter polar resin 3 has Mp = 10000, Mw = 12000, Tg = 94 ° C., acid value A = 18.2 mgKOH / g, acid value B = 51.0 mgKOH / g.

<Synthesis Example 4 of Styrenic Polar Resin>
In Synthesis Example 1 of the styrenic polar resin, the same procedure was performed except that the addition amount of the initiator was changed from 0.5 part to 0.35 part, and the additional initiator was changed from 0.1 part to 0.15 part. A styrene polar resin 4 which is a methacrylic acid-methyl methacrylate copolymer was obtained. This styrene meter polar resin 4 has Mp = 22000, Mw = 27000, Tg = 89 ° C., acid value A = 10.9 mgKOH / g, acid value B = 101.0 mgKOH / g.

<Synthesis Example 5 of Styrenic Polar Resin>
In Synthesis Example 1 of the styrenic polar resin, the addition amount of the initiator was changed from 0.5 part to 0.4 part, the additional initiator was changed from 0.1 part to 0.08 part, and the washing solvent was water / methanol = Styrene polar resin 5 which is a styrene-methacrylic acid-methyl methacrylate copolymer was obtained in the same manner except that the ratio was set to 70:30. This styrene meter polar resin 5 has Mp = 15000, Mw = 18000, Tg = 90 ° C., acid value A = 16.7 mgKOH / g, acid value B = 95.0 mgKOH / g.

<Synthetic Examples 6 to 22 of Styrenic Polar Resin>
In Synthesis Example 1 of the styrene polar resin, the addition amount of the initiator and the addition amount of the additional initiator were changed, and the styrene-methacrylic acid-methacrylic acid was similarly changed except that the ratio of water / methanol was changed with respect to the cleaning solvent. Styrenic polar resins 6 to 22 which are acid methyl copolymers were obtained. Table 1 shows the physical properties of these polar resins.

<Synthesis example 23 of polyester resin>
The following raw materials were put in a four-neck flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas introduction tube.
-57 mol% of diol components represented by the general formula (1)

（式中、Ｒはエチレン又はプロピレン基を表し、ｘ，ｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２〜１０である。本実施例では、Ｒは 、ｘ＋ｙの平均値は約３である。）
・フマル酸 １９ｍｏｌ％
・テレフタル酸 ２４ｍｏｌ％
さらに、触媒量のシュウ酸チタン化合物を入れ、四口フラスコに窒素ガスを通し撹拌しながら徐々に昇温し、１５０℃で１０時間反応し、縮重合反応の後半２００℃に温度を上げ、減圧下で縮重合反応をすすめ、重量平均分子量Ｍｗが１３０００の前駆ポリエステル樹脂１（酸価２４ｍｇＫＯＨ／ｇ、水酸基価１３ｍｇＫＯＨ／ｇ）を得た。

(In the formula, R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. In this example, R is the average value of x + y is About 3.)
・ Fumaric acid 19mol%
・ Terephthalic acid 24mol%
Furthermore, a catalytic amount of a titanium oxalate compound is added, nitrogen gas is passed through a four-necked flask, the temperature is gradually raised while stirring, the reaction is carried out at 150 ° C. for 10 hours, the temperature is raised to 200 ° C. in the latter half of the condensation polymerization reaction, The polycondensation reaction was carried out to obtain precursor polyester resin 1 (acid value 24 mgKOH / g, hydroxyl value 13 mgKOH / g) having a weight average molecular weight Mw of 13000.

  Thereafter, 100 parts of the precursor polyester resin 1 was put into a four-necked flask and heated to a temperature of 150 ° C., then 0.4 parts of trimellitic anhydride was added, and gradually heated, the polymer terminal of the precursor polyester resin 1 was trimellitic acid. Precursor polyester resin 2 modified with 1 was prepared.

  Thereafter, the precursor polyester resin 2 was washed with a solvent of water / ethanol = 60: 40 to obtain a polar resin 23. The acid value of the polar resin 23 was 18.0 mgKOH / g. The acid value C of the methanol-soluble component was 136.8 mgKOH / g.

<Synthesis Examples 24 to 34 of polyester resin>
The precursor polyester resin was adjusted by changing the monomer ratio, the catalyst addition amount, the trimellitic anhydride addition amount, and the reaction temperature with respect to the synthesis example 23, and then the precursor polyester resin was mixed with water / ethanol (ratio 80/20 to The resin was washed with a solvent of 40/60) to obtain polar resins 24 to 34. Table 1 shows the physical properties of these polar resins.

(Toner Production Example 1)
A polymerized toner was produced according to the following procedure.

  To 1300 parts of ion-exchanged water heated to 60 ° C., 9 parts of tricalcium phosphate is added and stirred at 10,000 r / min using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). Prepared.

Moreover, the following material was melt | dissolved at 100 r / min with the propeller-type stirring apparatus, and the solution was prepared.
Styrene 70.0 parts n-Butyl acrylate 30.0 parts Divinylbenzene 0.15 parts Polyester resin 23 3.0 parts (Mw = 14000, Tg = 72 ° C., acid value = 18.0 mgKOH / g, acid value C = 136) .8mgKOH / g)
Styrene polar resin 1:
Styrene-methacrylic acid-methyl methacrylate copolymer 12.0 parts (Mp = 12000, Mw = 15000, Tg = 92 ° C., acid value A = 15.0 mgKOH / g, acid value B = 76.0 mgKOH / g)

Next, carbon black Nipex 35 (manufactured by Degussa) 7.0 parts charge control agent (TN105: manufactured by Hodogaya Chemical Co., Ltd.) 1.0 part wax HNP-10 (melting point 75 ° C .: manufactured by Nippon Seiki Co., Ltd.) After 10.0 parts were added, the mixture was heated to a temperature of 60 ° C., and then stirred and dissolved and dispersed at 9,000 r / min with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.).

  In this, 10.0 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was put into the aqueous medium and stirred at 60 ° C. using a TK homomixer at 10,000 r / min for 30 minutes for granulation.

  Thereafter, the mixture was transferred to a propeller type stirring device and stirred at 100 r / min, reacted at 70 ° C. for 5 hours at 0.50% or less of dissolved oxygen in a nitrogen atmosphere, then heated to 80 ° C. and further 5 A time reaction was performed to produce toner particles. After completion of the polymerization reaction, the slurry containing the particles is cooled, hydrochloric acid is added to dissolve the tricalcium phosphate, the slurry is washed with 10 times the amount of water, filtered and dried, and the particle size is adjusted by classification to obtain black. Toner particles were obtained.

Hydrophobic silica fine powder (primary particle diameter) treated with dimethyl silicone oil (20% by mass) as a fluidity improver and charged to the same polarity (negative polarity) as the toner particles with respect to 100 parts of the black toner particles. : 15 nm, BET specific surface area: 100 m ^{2 /} g) 2.0 parts with a Henschel mixer (manufactured by Mitsui Miike Co., Ltd.) at 3000 r / min for 15 minutes. 1 was obtained.

  Black toner no. The physical properties of No. 1 are shown in Table 2, and the evaluation results are shown in Tables 4 and 5 (the evaluation method will be described later).

(Toner Production Examples 2 to 4)
Changed to styrene resin and polyester resin as shown in Table 1 instead of styrene resin and polyester resin in Toner Production Example 1, and changed addition amount, and changed initiator addition amount and reaction temperature at the time of reaction. Then, toner was manufactured in the same manner as in Toner Preparation Example 1 to obtain black toners 2 to 4. Table 2 shows the physical properties of Toners 2 to 4 obtained.

(Black toner production example 5)
-Polar polyester resin (23) 50 parts-Styrene polar resin (1) 50 parts-Wax HNP-10 (melting point 75 ° C: manufactured by Nippon Seiki Co., Ltd.) 10 parts (DSC endothermic peak: 69 ° C, Mw: 700, Mn : 500)
Charge control agent: aromatic oxycarboxylic acid Zr compound (TN105: manufactured by Hodogaya Chemical Co., Ltd.) 4 partsPigment: black pigment 10 parts (carbon black Printex 30 pH: 9.5)
The above materials were kneaded and pulverized to obtain a pulverized product 1.

  Thereafter, classification was performed to obtain black particles 5. Thereafter, 0.2 part of hydrophobized titania fine powder and 1.3 part of hydrophobized silica fine powder were added to 100 parts of black particles 5, and a Henschel mixer manufactured by Mitsui Mining Co., Ltd. Was used to uniformly diffuse to obtain a black toner 5. Table 2 shows the physical properties of the black toner 5.

(Toner Production Example 6)
Toner was produced in the same manner as in Toner Production Example 5 except that the pulverized product 1 of Toner Production Example 5 was subjected to a surface treatment using a machine of a type with a rotating rotor, and Black Toner 6 was obtained. Table 2 shows the physical properties of Toner 6 thus obtained.

(Toner Production Example 7)
(Pigment dispersion method)
A pigment dispersion was prepared by the following procedure.
Black pigment: (Printtex 30) 96 parts Pigment dispersant:
Alcohol-modified polyethylene resin (Mw: 7000) 4 parts, ethyl acetate 100 parts Dispersed with a dispersion machine such as dispersion attritor (Mitsui Mining Co., Ltd.) with the above material composition, and then diluted with ethyl acetate to give a pigment with a pigment concentration of 15% A dispersion was prepared.

(Preparation of wax-dispersed particles)
A dispersion of micronized wax was prepared by the following procedure.
Paraffin wax (1): 20 parts (DSC endothermic peak: 69 ° C., Mw: 700, Mn: 500)
-Toluene 80 parts The above materials were charged into a disperser. While stirring, the temperature was gradually raised to 100 ° C. and then cooled to room temperature to precipitate finely divided wax. The prepared dispersion of micronized wax was diluted with ethyl acetate so that the mass concentration of the wax was 20% by mass.

[Production of toner particles]
Polyester resin (1) 100 parts 30 parts of the above pigment dispersion, 25 parts of the above wax dispersion particle liquid, and 50 parts of ethyl acetate were dispersed with a ball mill (this liquid was designated as A liquid). On the other hand, after dispersing 60 parts of calcium carbonate (average particle size 80 nm) and 40 parts of water with a ball mill, 7 parts of calcium carbonate dispersion and carboxymethylcellulose (trade name “Serogen BS-H”: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A 100% aqueous solution was stirred (this solution was designated as solution B).

  Next, 100 parts of B liquid was stirred with an emulsifier (trade name “Auto Homo Mixer” manufactured by Tokushu Kika Kogyo Co., Ltd.), and 50 parts of A liquid was slowly added therein to suspend the mixed liquid. Thereafter, the solvent was removed, and hydrochloric acid was added to remove calcium carbonate, followed by washing with water, drying and classification to obtain black particles 7. Thereafter, 0.2 part of hydrophobized titania fine powder and 1.3 part of hydrophobized silica fine powder were added to 100 parts of black particles 7, and a Henschel mixer manufactured by Mitsui Mining Co., Ltd. Was used to uniformly diffuse to obtain a black toner 7. The physical properties are shown in Table 2.

(Toner Production Examples 8 to 21)
Change to styrene resin and polyester resin as shown in Table 2 instead of styrene resin and polyester resin in Toner Production Example 1, and change addition amount, and change initiator addition amount and reaction temperature at the time of reaction. Then, toner was manufactured in the same manner as in Toner Preparation Example 1 to obtain black toners 8 to 21. Table 2 shows the physical properties of Toner 8 to 21 obtained.

(Comparative toner production examples 22 to 33)
Changed to styrene resin and polyester resin as shown in Table 3 in place of styrene resin and polyester resin in Toner Production Example 1, and changed addition amount, and changed initiator addition amount and reaction temperature during reaction. Thus, toner was manufactured in the same manner as in Toner Preparation Example 1 to obtain black toners 22 to 33. Table 3 shows the physical properties of Toner 22 to 33 obtained.

<Examples 1 to 21 and Comparative Examples 1 to 12>
(Image evaluation)
Using the obtained toners 1 to 33, image evaluation was performed according to the following method.

  As an image forming apparatus, a remodeling machine in which the process speed of a commercially available laser printer CLJ-3700 (manufactured by HP) is changed to 250 mm / second is used, in a low temperature and low humidity environment (15 ° C., 10% RH) and high temperature and high It was carried out in a wet environment (30 ° C., 80% RH). Similarly, the fixing device was modified from the CLJ-3700 fixing device so that the temperature control and the applied pressure could be changed. The same cartridge for CLJ-3700 was used with the following changes.

(Manufacture of developing roller D-1)
As the shaft core, a SUS cylinder was plated with nickel, and a silane coupling primer was applied and baked. Next, the shaft core was placed in a mold, the mold was heated at 100 ° C. for 5 minutes, and conductive dimethyl silicone rubber (Asker C hardness 15 ° product) was injected into the cavity formed in the mold. Subsequently, the silicone rubber was vulcanized and cured by heating at 100 ° C. for 15 minutes, and after cooling, it was demolded to provide an elastic layer on the outer periphery of the shaft core body.

  Next, a necessary amount of TMP-modified TDI is added as a cross-linking material based on a chain-extended polyol, and the solid content of the urethane resin (total amount of the chain-extended polyol and isocyanate used as the cross-linking material) is 18. Dip solution obtained by adding 30 parts of carbon black (trade name: MA-100, manufactured by Mitsubishi Chemical Corporation) to the mixed solution containing methyl ethyl ketone as the main solvent adjusted so as to be mass% and sufficiently stirring. It was. The shaft core provided with the elastic layer in this liquid is immersed and coated, and then pulled up and dried, and the surface layer is provided on the outer periphery of the elastic layer by heat treatment at 120 ° C. for 5 hours. -1 was obtained.

As a transfer material, LETTER size XEROX 4024 paper (manufactured by XEROX, 75 g / m ² ) was used.

  As an evaluation of the present invention, a storage mode of 45 ° C./95%/7 days is provided as a pretreatment before image evaluation, and then an image with a print ratio of 1% in a high temperature and high humidity environment (H / H) is used. In the single color mode, 15000 sheets were printed by the continuous printing method shown below. The image forming speed was set to the speed in the plain paper mode.

  Image evaluation was performed based on the following evaluation criteria using the 100th, 5000th, and 10000th images.

  Each evaluation result is described in Tables 5 and 7.

[Developability evaluation method]
(Measurement of fogging)
The fog was measured using a REFECTOMETER MODEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) and calculated according to the following formula. A lower fog value is better.
Fog (reflectance;%) = (reflectance of standard paper;%) − (reflectance of white solid portion of sample;%)
A: 1.2% or less B: More than 1.2% and less than 2.0% C: More than 2.0% and less than 3.0% D: More than 3.0%

(Transfer efficiency)
The transfer efficiency is based on the basis weight of the toner developed on the photoconductor under the normal temperature and normal humidity (23 ° C./60%, N / N) condition using the image forming apparatus shown in FIG. The ratio of the toner basis weight transferred onto the paper was evaluated based on the following evaluation criteria.
A: 90% or more.
B: More than 75% and less than 90%.
C: More than 60% and less than 75%.
D: Less than 60%.

(Solid uniformity)
The obtained solid image on the transfer paper was evaluated as A, B, C, and D with a density difference of 5 points.
A: 0.1% or less B: Over 0.1% and 0.2% or less C: Over 0.2% and 0.3% or less D: Over 0.3%

(Drum fusion)
The drum fusion was evaluated based on the following evaluation criteria by visually observing the drum surface and further observing image defects.
A: Defects are not recognized at all on the drum surface and the image.
B: In the latter half of the durability, the drum surface is slightly stained but does not appear in the image.
C: In the latter half of the durability, some dirt is observed on the drum surface, and some unevenness occurs in the image.
D: In the latter half of the endurance, the drum surface is very dirty, and the image is uneven.

(Development roller dirty)
The developing roller stain was evaluated based on the following evaluation criteria by lightly wiping off the toner and visually observing the surface of the roller, further observing image defects.
A: Defects are not recognized at all on the roller surface and the image.
B: Stain is slightly observed on the roller surface in the latter half of durability, but does not appear in the image.
C: In the latter half of the durability, some dirt is observed on the roller surface, and some unevenness occurs in the image.
D: In the latter half of the durability, the roller surface is very dirty, and the image is uneven.

[Measurement method for fixability evaluation items]
Using each black toner, a belt-like image having a toner carrying amount of 0.5 to 0.6 dg / m ² is formed on the leading edge of the recording paper having a basis weight of 75 or 80 g / m ² and a fixing test is performed. It was. Fixing evaluation results are shown in Tables 4 and 6.

  The preparation of the unfixed image and the fixability test are performed under normal temperature and normal humidity (23 ° C./60%) unless otherwise specified.

The configuration of the fixing device is a heating fixing device modified for CLJ3700 as follows, and the oil application mechanism is omitted. As the pressure roller, a roller having a roller hardness of 60 degrees (Asker-C 500 g) obtained by coating a core rubber made of Fe with silicone rubber and PFA resin was used. As the pressing force, the pressure spring was adjusted to contact with a surface pressure of 90,000 N / m ² through 80 g / cm ² of paper, and the fixing nip was 6.0 mm.

(Fixing start temperature)
The unfixed image created by the above method is fixed by adjusting the temperature of the heating unit of the fixing device at a temperature range of 100 to 230 ° C. every 5 ° C., and a load of 4900 N / m ² is applied to the obtained fixed image. The temperature at which the image density reduction rate before and after rubbing is 10% or less is defined as the fixing start temperature. The following four ranks were evaluated according to the degree.
A: The fixing start temperature is less than 140 ° C.
B: The fixing start temperature is 140 ° C. or higher and lower than 150 ° C.
C: The fixing start temperature is 150 ° C. or higher and lower than 160 ° C.
D: The fixing start temperature is 160 ° C. or higher.

(High temperature offset resistance)
The fixing temperature is raised, and the highest temperature at which no offset phenomenon occurs visually is defined as a high temperature offset free temperature, which is used as an index of offset resistance. The following four ranks were evaluated according to the degree.
A: The high temperature offset free temperature is 190 ° C. or higher.
B: High temperature offset free temperature is 180 ° C. or higher and lower than 190 ° C.
C: High temperature offset free temperature is 170 ° C. or higher and lower than 180 ° C.
D: High temperature offset free temperature is less than 170 ° C.

(Fixing stability)
The unfixed image created by the above method is continuously fed through 10,000 sheets under the condition of the heating unit set temperature of 170 ° C., and the fixability of the first sheet and the 10,000th sheet is confirmed. The obtained fixed image is rubbed twice with sylbon paper applied with a load of 4900 N / m ² , and fixing is performed when the image density reduction rate before and after the rubbing becomes 10% or less. The following four ranks were evaluated according to the degree.
A: Initially fixed after passing 10,000 sheets and the reduction rate is 10% or less.
B: Fixed at the beginning, but not offset after passing 10,000 sheets, but the density reduction rate is 10% or more.
C: Initially fixed, but offset after 10,000 sheets passed, and the back surface is dirty.
D: Offset is in the initial stage.

(Image gloss (gloss) measurement)
The glossiness measuring instrument used in the present invention was PG-3D (incident angle θ = 75 °) manufactured by Nippon Denshoku Industries Co., Ltd., and the standard surface was black glass with a glossiness of 96.9. As charts, nine unfixed 30 mm × 30 mm patch unfixed images were output on Xerox 4024 paper (75 g paper) or CLC-SK paper (Canon).

(Gloss unevenness in the image: difference in image gloss)
Nine patch images of 30mm x 30mm size are output on Xerox 4024 paper (75g paper, legal size) or CLC-SK A3 size paper (Canon), heating unit set temperature 170 ° C, process speed Paper was passed under the condition of 150 mm / second. From the viewpoint of uneven gloss, the difference between the maximum value and the minimum value was evaluated among the gloss values at nine locations in the image when one sheet was passed.

The following four ranks were evaluated according to the degree.
A: The gross difference is less than 5.
B: The gloss difference is 5 or more and less than 10.
C: The gloss difference is 10 or more and less than 15.
D: The gloss difference is 15 or more.

  The following is an evaluation method for blocking resistance from the viewpoint of toner storage stability.

10 g of the toner after the external addition treatment was put in a polycup and left in an environment at 53 ° C. for 3 days, and the following four ranks were evaluated according to the degree.
A: When it tilts, it collapses easily.
B: Dama is present, but it collapses easily by shaking.
C: There are lumps that are easily broken but not unraveled when tilted.
D: Even if tilted, it does not collapse.

  DESCRIPTION OF SYMBOLS 1 Photosensitive drum, 2 Charging roller, 3 Exposure apparatus, 4 Developing apparatus, 5 Primary transfer roller, 6 Cleaning apparatus, 7 Fixing apparatus, 8 Waste toner container, 9 Developing roller, 10 Toner supply roller, 11 Toner control blade, 12 Toner Stirrer blade, 13 intermediate transfer belt, 14 pickup roller, 15 secondary transfer roller, 16 intermediate transfer belt cleaning device, 17 waste toner box, 18 paper transport belt, 19 paper discharge unit, 20 paper feed cassette

Claims (9)

A toner having at least a binder resin, a colorant, a styrene resin containing a carboxyl group, a toner particle containing a polyester resin and an inorganic fine powder, wherein the toner particle is produced in an aqueous medium,
When the acid value of the carboxyl group-containing styrene resin is A (mg KOH / g) and the acid value of the methanol-soluble component of the carboxyl group-containing styrene resin is B (mg KOH / g),
50 ≦ B ≦ 110 and 2.0 ≦ B / A ≦ 10
And the weight average molecular weight (Mw) of the styrene-based resin containing the carboxyl group is 10,000 to 30000,
When the acid value of the methanol-soluble component of the polyester resin is C (mg KOH / g),
1.1 ≦ C / B ≦ 3.0
The content of the styrene-based resin containing a carboxyl group with respect to 100 parts by mass of the binder resin is 8 to 30 parts by mass, and the content of the polyester resin with respect to 100 parts by mass of the binder resin is 1 to 10 parts by mass. A toner having a mass part.   2. The toner according to claim 1, wherein the carboxyl group-containing styrenic resin contains 0.05 to 1.0% by mass of a methanol-soluble component.   The toner according to claim 1, wherein the carboxyl group-containing styrenic resin has a cyclohexane insoluble component of 0.5% by mass or less.   The toner according to any one of claims 1 to 3, wherein the polyester resin contains a methanol-soluble component in an amount of 0.2 to 1.2% by mass. When the toner particles were left at 20 ° C., 40 ° C. and 50 ° C. for 12 hours and the methanol concentration (%) at 50% transmission by a methanol wettability tester was H20, H40 and H50, respectively,
15 <H20 <30 26 <H50 <45 H20 <H40 <H50 5 <H50-H40 <15
The toner according to claim 1, wherein the toner is a toner.   The toner according to any one of claims 1 to 5, wherein the toner has a cyclohexane-soluble content of 60 to 100% by mass.   The toner according to any one of claims 1 to 6, wherein the toner has a viscosity of from 5000 to 30,000 at 100 ° C.   The toner according to any one of claims 1 to 7, wherein the toner has an average circularity of 0.960 to 0.990.   The toner according to claim 1, wherein the toner particles are produced by a suspension polymerization method in an aqueous medium.

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