JP2011118210A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner capable of acquiring an image having high precision and high image quality which is stable for a long period by securing simultaneously toner flowability, charge stability, developability, transferability and image density stability. <P>SOLUTION: The toner has toner particles including at least a binding resin and a coloring agent, and at least silica-titania composite particles. In the silica-titania composite particle, the content rate of silica is not less than 55.0 mass% and not more than 85.00 mass%, and zeta potential is not lower than -45.0 mV and not higher than -20.0 mV. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner used for electrophotographic image formation represented by copying machines and printers.

  An electrostatic image developing toner that can be used for electrophotographic image formation (hereinafter also simply referred to as toner) is made by adding particles made of an inorganic compound or resin called an external additive to its surface. There are many things.

  The presence of such an external additive improves the performance of the toner, such as chargeability and fluidity, and the use of the external additive is considered as one of the effective means for realizing good image formation.

  On the other hand, in recent years, there has been an increasing demand for high definition and high image quality in printers and the like, and in this technical field, attempts have been made to achieve high image quality by reducing the particle diameter of toner. Particularly in the case of color toners, the toner particle size is further reduced by the appearance of toners prepared not only by dry methods but also by wet suspension polymerization methods, agglomerated particle methods, and dissolution suspension polymerization methods. Accelerated. When the toner particle diameter is reduced, the charge amount per unit mass tends to increase, resulting in a decrease in image density and deterioration in durability. One of the causes is a decrease in the toner development amount with respect to the latent image on the photoreceptor. This can be done by considering how much toner amount the potential well can be filled with. However, as described above, since the charge amount per unit mass increases as the toner particle size becomes smaller, the development amount decreases with smaller toner. Cheap. The other is a reduction in efficiency (hereinafter referred to as transferability) of transferring the toner image on the photosensitive member to a transfer material or an intermediate transfer member. In general, the toner is electrically transferred from the photosensitive member to the transfer material or the intermediate transfer member. However, when the particle diameter of the toner is reduced, the non-electrostatic adhesion force is relatively increased. This is due to a decrease in efficiency. Further, since the surface area per unit mass of the toner is increased, it is easily expected that the fluidity of the toner is greatly deteriorated. Therefore, it is important that the toner is configured so that the problems of chargeability, transferability, and fluidity are compatible when the particle size of the toner is reduced. For the purpose of improving these, External additives such as particles and titania particles are often used.

  For the purpose of further improving the performance of silica and titania, composite particles containing silica and titania that do not have the harmful effects of silica and titania and have synergistic characteristics of each have been studied. For example, a toner using titania-containing external additive made of silica whose surface is hydrophobized (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5) is proposed. Has been. Further, titania composite particles containing silica (for example, see Patent Document 6) have been proposed.

  However, the composite particles described in Patent Documents 1, 2, and 3 are described as having good retention of charging characteristics during long-term continuous use. However, the composite particles have insufficient hydrophobicity or surface treatment with an aminosilane compound. Therefore, there is a concern about deterioration of charging characteristics due to continuous use or leaving in a high temperature and high humidity environment. Furthermore, the composite particles described in Patent Documents 1, 2, and 5 contain silica in titania, or the surface of titania is coated with silica. However, since the surface coating with silica is insufficient, titania exists on the surface, or there are titania single particles not surface-coated with silica. The composite particles described in Patent Document 3 have a sea-island structure in which the content of titania is less than that of silica and silica is distributed in a sea shape and titania is distributed in an island shape. Even titania is distributed. For this reason, the volume resistivity of these composite particles is as low as titania, which can improve the charge build-up property, prevention of charge-up, environmental stability, and uniformity of charge distribution. Performance is likely to deteriorate, and fog, transferability, and image density stability are likely to deteriorate. Patent Document 6 describes that the titania content of the silica-titania composite particles is 50% by mass or more and is excellent in environmental stability and charging stability, but because of the large titanium content, for long-term continuous use, There is concern about the decrease in fluidity and chargeability. Further, the composite particles of Patent Document 5 are described that the titania content of the silica-titania composite particles is large and the fluidity after standing for a long time can be maintained by defining the particle diameter of the composite particles. Is unclear, and there is concern about the fluidity retention in a high temperature and high humidity environment.

  In addition, hydrophobic particles (for example, see Patent Document 7) whose surface is coated with titania on silica particles, and silica particles (for example, see Patent Document 8) that have been hydrophobized with titanium alkoxide on the silica surface are described. However, when silica particles are surface-coated with titania or titanium alkoxide, the characteristics and harmful effects of titania with a small volume resistivity are dominantly expressed, and the good characteristics of silica are difficult to express. Performance tends to be lowered, and fog, transferability and image density stability tend to deteriorate.

  In any of these composite particles, it has been difficult to obtain a toner in which the adverse effects of silica and titania are improved and the composite particles having the respective good characteristics synergistically added are externally added.

Japanese Patent Registration No. 3587671 Japanese Patent Registration No. 358672 JP 2009-237338 A JP 2006-306651 A JP 2008-112046 A Special registration No. 2503370 JP 2003-322998 A JP 2004-155648 A

  An object of the present invention is to provide a toner that is excellent in fluidity, charging stability, developability, transferability, and image density stability, and that can stably obtain high definition and high image quality over a long period of time.

  As a result of intensive studies, the present inventors have found that the above requirements can be satisfied by using specific silica titania composite particles in which the silica content and the zeta potential are controlled as an external additive of the toner, and the present invention has been achieved. It came to do.

More specifically, the present invention provides a toner in which the adverse effects of silica and titania as described above are improved, and silica-titania composite particles externally added with synergistic combinations of the respective good characteristics. Resolve.
That is, the above object can be solved by using the following toner.

  A toner having at least a binder resin and a colorant, and at least silica-titania composite particles, wherein the silica-titania composite particles have a silica content of 55.0 mass% or more and 85.0 mass% or less. A toner having a zeta potential of −45.0 mV to −20.0 mV.

  In the toner of the present invention, silica titania composite particles whose silica content and zeta potential are controlled are externally added so that the toner has fluidity, charging stability, developability, transferability, and image density stability. It is possible to obtain a high-definition and high-quality image that is stable over a long period of time.

The TEM photograph of the silica titania composite particle (silica content 70.0 mass%) of this invention is shown. The schematic explanatory drawing of the measuring apparatus for measuring the volume specific resistance of a silica titania composite particle is shown.

  As a result of extensive studies on the silica content of the silica-titania composite particles and the structure and physical properties of the toner with external addition of silica-titania composite particles, the inventors have found that a toner that solves the above-mentioned problems can be obtained, and completed the present invention. I came to let you.

  In the present invention, the silica-titania composite particles are untreated or hydrophobized, and the zeta potential of the silica-titania composite particles measured in the untreated state is from −45.0 mV to −20.0 mV, Preferably they are -40.0 mV or more and -25.0 mV or less.

  The zeta potential is −20.0 mV or less, and is within the range of the silica content described later, which means that the silica-titania composite particles of the present invention have a core-shell structure as shown in FIG. Or an island-like structure.

  Conventional composite particles containing silica and titania do not have a structure in which titania is encapsulated in silica, unlike the silica-titania composite particles of the present invention, and titania is exposed on the surface. It becomes a high value close to titania particles.

  Since the silica-titania composite particles of the present invention have the structure as described above, titania having a small volume resistivity hardly exists on the surface, and has a zeta potential as small as silica. Therefore, there are no harmful effects of silica and titania, and composite particles containing silica and titania that have synergistic characteristics of the respective properties are obtained. For this reason, the toner externally added with the silica-titania composite particles of the present invention, when left for a long period of time, even when left for a long period of time, particularly under high humidity, has good charge retention and good start-up properties. , Transferability and fog characteristics can be maintained over a long period of time.

  Moreover, charge up is suppressed when used continuously for a long time.

  When the zeta potential of the silica-titania composite particles is less than −45.0 mV, the negative charge imparting ability to the toner becomes too large, and the same harmful effects as the silica particles are manifested. The amount of charge fluctuations increases. On the other hand, when it is larger than −20.0 mV, it indicates that titania is present on the particle surface, or there are many titania single particles not containing silica, and the same harmful effects as the titania particles are exhibited. For example, when left for a long period of time under high humidity, there are problems such as poor charge maintenance and poor transferability, fogging and image density stability.

[Method of measuring zeta potential]
The zeta potential of silica-titania composite particles was measured using Zeta Sizer-Nano-Zs (manufactured by Sysmex Corporation). As a dispersion, 7 mg of silica-titania composite particles were added to 100 mg of methanol at 25 ° C., and dispersed for 3 minutes with an ultrasonic disperser (manufactured by Nihon Riken Kikai Co., Ltd.) to obtain a dispersion. However, when white sediment and suspended matters of silica-titania composite particles are present in the dispersion, the amount of silica-titania composite particles added to methanol is appropriately adjusted. This dispersion is put with a dropper so that bubbles do not enter the DTS1060C-Clear Disposable Zeta Cell. This cell was attached to a measuring instrument, and the zeta potential was measured at 25 ° C. This measurement was performed and the average value of 5 times was taken as the zeta potential of the present invention.

  In the present invention, the ratio of the titania single particles or the silica single particles is preferably set to be composite particles containing silica and titania that have no adverse effects of silica and titania and have synergistic properties of the respective properties. It is 8.5 frequency% or less, More preferably, it is 4.5 frequency% or less. If the ratio is less than this ratio, it is possible to obtain silica-titania composite particles that further suppress the adverse effects of conventional silica particles and titania particles and further synergistically combine the good characteristics of silica and titania.

[Measurement of the Abundance Ratio of Silica Single Particles and Titania Single Particles]
The abundance ratio of silica single particles and titania single particles can be grasped by observation with a transmission electron microscope (TEM-EDX). Specifically, in observation with a transmission electron microscope (TEM-EDX), for example, observation and element mapping are performed at a magnification of 100,000 to 200,000 times in a continuous field of view, and Si and When the element of Ti is mapped, the same particle in which both the Si and Ti elements are observed is defined as a composite particle, and the one in which only one of the elements is observed is defined as a single particle. By this observation, the number of uncomplexed particles per 100 particles is defined as the existence ratio of single particles.

  The silica-titania composite particles of the present invention have a silica content of 55.0 mass% to 85.0 mass%, preferably 65.0 mass% to 75.0 mass%. When the silica content is less than 55.0% by mass, even if the silica-titania composite particles having the above-mentioned zeta potential are used, since the titania content is large, charging is performed particularly under high humidity when left for a long time. Is difficult (a loss of charge is large), and image density stability, transferability, and fog are deteriorated. When the silica content is larger than 85.0% by mass, even if the silica titania composite particles having the zeta potential described above are used, the silica content is high. In addition, the variation in charge amount between low-temperature and low-humidity environments increases and image density stability deteriorates.

[Method of measuring silica (SiO ₂ ) content of silica-titania composite particles]
The silica content of the silica-titania composite particles is measured by performing fluorescent X-ray analysis using a fluorescent X-ray analyzer SYSTEM3080 (manufactured by Rigaku Denki Kogyo Co., Ltd.) according to JIS K0119 “General rules for fluorescent X-ray analysis”.

  The silica-titania composite particle of the present invention is preferably hydrophobized in order to obtain more environmental stability, and the zeta potential of the silica-titania composite particle measured in the hydrophobized state is −40.0 mV or more. It is preferably −20.0 mV or less.

  If it is less than −40.0 mV, the negative chargeability is large, and the silica-titania composite particles tend to aggregate together, the fluidity of the toner deteriorates, and the fog may deteriorate. In addition, there may be a large variation in charge amount in a high temperature and high humidity or low temperature and low humidity environment. If it is larger than −20.0 mV, the ability to impart negative charge to the toner is low, so fogging and the like may deteriorate under high humidity.

  As described above, the zeta potential of the silica-titania composite particles measured in an untreated state is an important parameter that greatly affects the adverse effects of images before and after being left for a long time and / or after being continuously used for a long time. On the other hand, the zeta potential of silica-titania composite particles measured in a state of being hydrophobized is a parameter that greatly contributes to the image damage of each sheet. Therefore, in order to continue to produce a stable image regardless of how it is used for a long time, it is important that the zeta potential before and after the hydrophobization of the silica-titania composite particles is within the range specified in the present application.

  As the hydrophobization treatment of the silica-titania composite particles of the present invention, known treatment agents and methods can be used without particular limitation.

  Hydrophobic treatment in the dry method includes a method in which a silica-titania composite particle is treated with a hydrophobizing agent (including a method in which the silica-titania composite particle is sprayed with a hydrophobizing agent vapor under stirring or flow), water or organic The treatment method such as a method of immersing in a solvent such as a compound and treating the silica-titania composite particles with a hydrophobizing agent in a wet manner is not particularly limited, and any known method can be used without any problem.

  Among them, the dry method is preferable in that it has moderate low chargeability and excellent charge rising properties, weak cohesiveness, and excellent fluidity imparting properties.

  Examples of the dry method include a method of treating silica titania composite particles by spraying a hydrophobizing agent with stirring, and a method of introducing hydrophobizing agent vapor into a fluidized bed or stirring silica titania composite particles.

  As the hydrophobizing agent, a known treating agent can be used without any limitation. Specifically, as a silylating agent, chlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, vinyltrichlorosilane, tetramethoxysilane, methyl Trimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxy Silane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyl Diethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyltriethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) Alkoxysilanes such as aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hex Buchirujishirazan, hexa pliers distearate disilazane, hexa hexyl disilazane, hexa cyclohexyl disilazane, there hexaphenyl disilazane, divinyl tetramethyl disilazane, silazanes such as dimethyl tetra-vinyl disilazane and the like. Also, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, alkyl modified silicone oil, chloroalkyl modified silicone oil, chlorophenyl modified silicone oil, fatty acid modified silicone oil, polyether modified silicone oil, alkoxy modified silicone oil, Silicone oils such as diol-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, and terminal-reactive silicone oil, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane Siloxanes such as octamethyltrisiloxane are also preferred as the hydrophobizing agent. Furthermore, fatty acids and their metal salts include undecyl acid, lauric acid, tridecyl acid, dodecyl acid, myristic acid, palmitic acid, pentadecyl acid, stearic acid, heptadecyl acid, arachidic acid, montanic acid, oleic acid, linoleic acid, arachidonic acid Long metal fatty acids such as zinc, iron, magnesium, aluminum, calcium, sodium, lithium and other metals are effective as hydrophobizing agents. Among these, alkoxysilanes, silazanes, and straight silicone oil are preferable because they are easy to carry out. In the present invention, one type of such a hydrophobizing agent is used alone, or in the case of two or more types, they are mixed, or the surface treatment is sequentially carried out to obtain the required hydrophobicity according to the application. Can be achieved.

  In the present invention, the hydrophobization degree (methanol hydrophobization degree) of silica titania composite particles measured in a hydrophobized state for the purpose of obtaining desired characteristics, that is, long-term environmental stability, is preferably 60% by volume. It is 90 volume% or less, More preferably, it is 70 volume% or more and 85 volume% or less. When the degree of hydrophobicity is less than 60% by volume, the hygroscopicity becomes high, and the charging stability of the toner between low temperature, low humidity, high temperature, and high humidity environments tends to deteriorate. When the degree of hydrophobicity is greater than 90% by volume, the silica-titania composite particles are substantially treated with a large amount of the hydrophobizing agent, so that the silica-titania composite particles tend to aggregate and the toner fluidity tends to deteriorate. This may cause harmful effects such as fogging.

(Measurement of hydrophobicity)
First, in order to remove bubbles and the like in a measurement sample, 70 ml of a hydrated methanol solution composed of 60% by volume of methanol and 40% by volume of water is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm. Disperse for 5 minutes with an ultrasonic disperser.

  Next, 0.1 g of silica-titania composite particles are precisely weighed and added to a container containing the above-mentioned hydrated methanol solution to prepare a sample solution for measurement.

Then, the measurement sample solution is set in a powder wettability tester “WET-100P” (manufactured by Reska). The sample liquid for measurement is stirred at a speed of 6.7 s ⁻¹ (400 rpm) using a magnetic stirrer. As the rotor of the magnetic stirrer, a spindle type rotor having a length of 25 mm and a maximum barrel diameter of 8 mm coated with a fluororesin is used.

  Next, through this device, methanol is continuously added at a drop rate of 1.3 ml / min, and the transmittance is measured with light having a wavelength of 780 nm to create a methanol drop transmittance curve. Then, the methanol concentration at the end point where the transmittance is minimized is defined as the degree of hydrophobicity.

In addition, the silica titania composite particles of the present invention have a volume resistivity of 1.0 × 10 ⁴ Ω · m or more and 1.0 × 10 ⁸ Ω · m or less, measured in an untreated state, hydrophobic It is preferable that the volume resistivity of the silica-titania composite particles measured in the state of being treated is 1.0 × 10 ¹² Ω · m or more and 1.0 × 10 ¹⁴ Ω · m or less.

  Similar to the zeta potential described above, setting the volume resistivity before and after the hydrophobization treatment of the silica-titania composite particles within the scope of the present application is important for continuing to produce a stable image for a longer time. In other words, the volume resistivity before the hydrophobization treatment is an important parameter that greatly affects the adverse effects on images when used for a long time before and after being left for a long time. In addition, the volume resistivity after the hydrophobization process is an important parameter that greatly contributes to the harmful effect of each image.

Specifically, when the volume resistivity of the silica-titania composite particles measured in an untreated state is smaller than 1.0 × 10 ⁴ Ω · m, titania exists on the particle surface, or titania alone containing no silica Indicates that there are many particles. For this reason, when left for a long time under high humidity, the charge maintaining property is poor, and adverse effects such as transfer properties, fogging, and image density stability are likely to occur. If it is larger than 1.0 × 10 ⁸ Ω · m, the toner will not be moderately charged when used under low humidity for a long time, and it will be easy to charge up when used continuously for a long time. Defects such as deterioration of stability are likely to occur.

When the volume resistivity of the silica-titania composite particles measured in a hydrophobized state is less than 1.0 × 10 ¹² Ω · m, the charge distribution is likely to spread when used under high humidity, Transferability tends to deteriorate. When the volume resistivity of silica-titania composite particles measured in a hydrophobized state is greater than 1.0 × 10 ¹⁴ Ω · m, the negative chargeability of the toner becomes high and the developability deteriorates under low humidity. There is.

[Method of measuring volume resistivity]
FIG. 2 shows an apparatus for measuring the volume resistivity of silica-titania composite particles used in the present invention. Cell A is filled with silica-titania composite particles, electrodes 1 and 2 are placed in contact with the silica-titania composite particles, voltage is applied between the electrodes, current flowing at that time is measured, and specific volume is determined by specific resistance. A method for obtaining resistance was used. In the above measurement method, since the silica-titania composite particles are powder, a change occurs in the filling rate, and accordingly, the volume specific resistance may change. In the present invention, the volume resistivity is measured under the following conditions: the contact area S between the silica-titania composite particles and the electrode is about 2.3 cm ² , the sample thickness d is 1.0 mm to 1.5 mm, and the load of the upper electrode 22 is 180 g. And Further, the applied voltage was increased by 200 V at 30 second intervals, and the specific resistance measured at the applied voltage of 1000 V was defined as the volume resistivity of the present invention.

The silica titania composite particles of the present invention have a BET specific surface area measured in an untreated state, preferably 20 m ² / g or more and 350 m ² / g or less, more preferably 45 m ² / g or more and 330 m ² / g or less. is there. When the particle size is less than 20 m ² / g, the particle size distribution of the silica-titania composite particles becomes wide, and the fluidity of the toner may be deteriorated or the charge distribution may be widened. On the other hand, when it is larger than 350 m ² / g, it is difficult to obtain a structure in which titania is encapsulated in silica as shown in FIG.

[Method for measuring BET specific surface area of silica-titania composite particles]
The BET specific surface area is measured according to JIS Z8830 (2001). A specific measurement method is as follows.

  As a measuring device, an “automatic specific surface area / pore distribution measuring device TriStar 3000 (manufactured by Shimadzu Corporation)” which employs a gas adsorption method by a constant volume method as a measuring method is used. Setting of measurement conditions and analysis of measurement data are performed using dedicated software “TriStar3000 Version 4.00” attached to the apparatus, and a vacuum pump, a nitrogen gas pipe, and a helium gas pipe are connected to the apparatus. The value calculated by the BET multipoint method using nitrogen gas as the adsorption gas is defined as the BET specific surface area in the present invention.

  The BET specific surface area is calculated as follows.

First, nitrogen gas is adsorbed on silica particles, and then the equilibrium pressure P (Pa) in the sample cell and the nitrogen adsorption amount Va (mol · g ⁻¹ ) of the silica particles are measured. The relative pressure Pr, which is a value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, is plotted on the horizontal axis, and the nitrogen adsorption amount Va (mol · g ⁻¹ ) is plotted on the vertical axis. The adsorption isotherm is obtained. Next, a monomolecular layer adsorption amount Vm (mol · g ⁻¹ ), which is an adsorption amount necessary for forming a monomolecular layer on the surface of the toner, is obtained by applying the following BET equation.
Pr / Va (1-Pr) = 1 / (Vm * C) + (C-1) * Pr / (Vm * C)
(Here, C is a BET parameter, which is a variable that varies depending on the measurement sample type, adsorbed gas type, and adsorption temperature.)

The BET equation is interpreted as a straight line with an inclination of (C-1) / (Vm × C) and an intercept of 1 / (Vm × C), where Pr is X axis and Pr / Va (1-Pr) is Y axis. Yes (this line is called a BET plot).
Straight line slope = (C-1) / (Vm × C)
Straight line intercept = 1 / (Vm × C)

  When the measured value of Pr and the measured value of Pr / Va (1-Pr) are plotted on a graph and a straight line is drawn by the least square method, the slope and intercept value of the straight line can be calculated. Vm and C can be calculated by solving the above slope and intercept simultaneous equations using these values.

Further, the BET specific surface area S (m ² · g ⁻¹ ) of the toner is calculated from the calculated Vm and the molecular occupation cross-sectional area of the nitrogen molecule (0.162 nm ² ) based on the following formula.
S = Vm × N × 0.162 × 10 ⁻¹⁸
(N is Avogadro's number (mole- ¹ ).)

  The measurement using this apparatus follows the “TriStar 3000 Instruction Manual V4.0” attached to the apparatus, and specifically, the measurement is performed according to the following procedure.

  Thoroughly weigh the tare of a dedicated glass sample cell (stem diameter 3/8 inch, volume about 5 ml) that has been thoroughly cleaned and dried. Then, about 0.5 g of silica particles are put into this sample cell using a funnel.

  The sample cell containing the silica-titania composite particles is set in a “pretreatment device Bacuprep 061 (manufactured by Shimadzu Corporation)” connected with a vacuum pump and a nitrogen gas pipe, and vacuum degassing is continued at 23 ° C. for about 10 hours. To do. In vacuum degassing, the gas is gradually degassed while adjusting the valve so that silica particles are not sucked into the vacuum pump. The pressure in the cell gradually decreases with deaeration and finally becomes about 0.4 Pa (about 3 mTorr). After completion of vacuum degassing, nitrogen gas is gradually injected to return the inside of the sample cell to atmospheric pressure, and the sample cell is removed from the pretreatment device. Then, the mass of the sample cell is precisely weighed, and the exact mass of the silica particles is calculated from the difference from the tare. At this time, the sample cell is covered with a rubber plug during weighing so that the silica particles in the sample cell are not contaminated by moisture in the atmosphere.

  Next, a dedicated “isothermal jacket” is attached to the stem portion of the sample cell containing the silica-titania composite particles. Then, a dedicated filler rod is inserted into the sample cell, and the sample cell is set in the analysis port of the apparatus. The isothermal jacket is a cylindrical member having an inner surface made of a porous material and an outer surface made of an impermeable material capable of sucking liquid nitrogen to a certain level by capillary action.

  Subsequently, the free space of the sample cell including the connection tool is measured. Free space is measured by measuring the volume of the sample cell with helium gas at 23 ° C., and then measuring the volume of the sample cell after cooling the sample cell with liquid nitrogen in the same manner using helium gas. Calculated from the difference in volume. Further, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured separately using a Po tube built in the apparatus.

  Next, after performing vacuum deaeration in the sample cell, the sample cell is cooled with liquid nitrogen while continuing the vacuum deaeration. Thereafter, nitrogen gas is gradually introduced into the sample cell to adsorb nitrogen molecules on the silica particles. At this time, the adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) as needed, and the adsorption isotherm is converted into a BET plot. Note that the points of the relative pressure Pr for collecting data are set to a total of 6 points of 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30. A straight line is drawn from the obtained measurement data by the least square method, and Vm is calculated from the slope and intercept of the straight line. Further, using the value of Vm, the BET specific surface area of the silica-titania composite particle is calculated as described above.

  Hereinafter, a method for producing silica-titania composite particles will be described.

  The silica-titania composite particles of the present invention can be used without particular limitation by a known production method.

  For example, a method of attaching silica to the surface of titania particles in an aqueous medium, a method of doping, a gas phase method, and the like can be given.

  Among these, as a production method for obtaining silica-titania composite particles having the structure shown in FIG. 1 and having a desired zeta potential, a gas phase method is preferable.

  A method for producing silica-titania composite particles by a gas phase method is, for example, introducing silicon tetrachloride gas and titanium tetrachloride gas together with an inert gas into a mixing chamber of a combustion burner and mixing with hydrogen and air at a predetermined ratio. This gas mixture is combusted in a reaction chamber at a temperature of 1000 ° C. or higher and 3000 ° C. or lower to produce silica titania composite oxide particles, which are cooled and collected by a filter.

  In the above production method, in order to obtain silica-titania composite particles having the structure shown in FIG. 1 and having a desired zeta potential, the reaction rate difference for generating silica from silicon tetrachloride gas and titania from titanium tetrachloride gas is changed. Considering (the reaction rate of titania generation reaction is faster than silica generation reaction), the flow rate ratio of silicon tetrachloride gas and titanium tetrachloride gas introduced into the combustion burner, combustion time and temperature, combustion atmosphere, and others It is important to adjust in combination according to the combustion conditions.

  In addition, the silica-titania composite particles of the present invention may be pulverized before, after, or simultaneously with the hydrophobizing treatment, for the purpose of improving fluidity. As the crushing method, a known crusher can be used. For example, there is a method of crushing the surface-treated silica titania composite particles with a high-speed impact type fine crusher pulverizer (manufactured by Hosokawa Micron).

  The addition amount (external addition amount) of the silica-titania composite particles of the present invention to the toner is preferably 0.01 parts by weight or more and 2.50 parts by weight or less, more preferably 0.8 parts by weight with respect to 100 parts by weight of the toner particles. 10 parts by mass or more and 2.00 parts by mass or less. Within this range, the effects of the silica-titania composite particles that have been described in detail can be maximized.

  Next, the toner particles and toner of the present invention will be described.

  The toner particles of the present invention preferably contain 30 ppm or more and 1000 ppm or less of titanium element.

  When a predetermined amount of titanium element is contained in the toner particles, due to the interaction with the silica-titania composite particles externally added to the toner particles of the present invention, charges are appropriately exchanged between the toners, and the charge amount is reduced. In addition, it is possible to suppress the charge-up and increase the saturation charge amount in a state where the charge rising property (charging speed) and charge distribution of the toner are good.

  When the content of titanium element in the toner particles is less than 30 ppm, it becomes difficult for the toners to be relieved of charge, widening the charge distribution and facilitating charge-up. In addition, when the content of titanium element in the toner particles is more than 1000 ppm, the loss of charge from the toner becomes large when left for a long time, and fog and transferability are liable to deteriorate particularly under high humidity.

(Measurement of titanium element content in toner particles)
The measurement of the fluorescent X-ray of each element is in accordance with JIS K 0119-1969, and is specifically as follows.

  As a measuring device, a wavelength dispersion type fluorescent X-ray analyzer “Axios” (manufactured by PANalytical) and attached dedicated software “SuperQ ver. 4.0F” (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data ) Is used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. Further, when measuring a light element, it is detected by a proportional counter (PC), and when measuring a heavy element, it is detected by a scintillation counter (SC).

  As a measurement sample, about 4 g of toner particles are put in a dedicated aluminum ring for press and flattened, and using a tablet molding compressor “BRE-32” (manufactured by Maekawa Test Co., Ltd.) at 20 MPa, Pellets formed by pressing for 60 seconds and having a thickness of about 2 mm and a diameter of about 39 mm are used.

  The measurement is performed under the above conditions, the element is identified based on the obtained X-ray peak position, and the concentration is calculated from the count rate (unit: cps) which is the number of X-ray photons per unit time.

  As a method of containing titanium element in the toner particles of the present invention, a known method can be used without any particular limitation.

  Hereinafter, an example of toner particles having a prescribed amount of titanium element and capable of exhibiting the above effects will be described in detail.

  An example of the toner is toner particles containing a polar resin having a polyester unit synthesized using a titanium chelate compound as a catalyst.

  The present inventors have found an effect presumed to be caused by an unexpected interaction in a toner particle including a silica-titania composite particle to be externally added and a polar resin having a polyester unit using a titanium chelate catalyst. Although the reason is not clear, the toner in which the silica-titania composite particles are externally added to the polar resin-containing toner particles having a polyester unit using a titanium chelate catalyst has a high adsorption state, and even when continuous printing is performed, the silica-titania Since the ratio of the composite particles released from the toner particles is small, it was possible to stably provide high image quality over a long period of time. The height of the adhering state is presumed to be an effect due to the interaction between the charging speed of the polyester resin and the saturation charge required, and the zeta potential of the silica-titania composite particles and the titanium chelate catalyst residue in the resin.

  Further, this effect becomes remarkable in the case of a toner obtained by a suspension polymerization method or an agglomerated particle method in which a polar resin can be further present on the toner surface. The polar resin using the titanium chelate catalyst makes it possible to stably hold the silica-titania composite particles that control the fluidity and charging stability of the toner on the toner surface over a long period of time. Therefore, the effect of the interaction between the polar resin and the silica-titania composite particles can be maintained for a long time, and a high-definition and high-quality image targeted by the present invention can be obtained.

  Furthermore, the characteristic of the polar resin which has a polyester unit using a titanium chelate catalyst is explained in full detail.

  In the titanium chelate compound used in the present invention, the ligand is preferably any one of diol, dicarboxylic acid, and oxycarboxylic acid. Among these, the ligand is particularly preferably an aliphatic diol, dicarboxylic acid, or oxycarboxylic acid. Aliphatic ligands are preferred because they have higher catalytic activity than aromatic ligands, are preferable in terms of shortening the reaction time and temperature control, and the resin physical properties are likely to be sharp in molecular weight distribution.

  Specific examples of the ligand include 1,2-ethanediol, 1,2-propanediol, and 1,3-propanediol as the diol. Dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and oxycarboxylic acid, such as glycolic acid, lactic acid, hydroxyacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid , Tartaric acid, citric acid.

  Moreover, when polymerizing the polar resin having the polyester unit of the present invention, the addition amount of the titanium chelate compound is 0.01% by mass or more and 2.00% by mass or less, preferably 0%, based on the total amount of the polyester unit component. 0.05 mass% or more and 1.00 mass% or less, More preferably, 0.10 mass% or more and 0.70 mass% or less are good. When it is less than 0.01% by mass, the reaction time during the polymerization of the polyester becomes long and the molecular weight distribution becomes broad, making it difficult to give good fixability when the toner is used. On the other hand, when the content exceeds 2% by mass, the charging characteristics of the toner are affected, and the fluctuation of the charge amount due to the environment tends to increase.

  The polar resin contained in the toner of the present invention may be a resin having at least a polyester unit, and the polyester unit component contained in the total resin is 3% by mass or more, thereby exhibiting the effect of the present invention. Therefore, it is preferable. If it is less than 3% by mass, it may be difficult to obtain particularly good charging characteristics among the effects of the present invention.

  The acid value (mgKOH / g) of the polar resin used in the present invention is preferably 3 or more and 35 or less, more preferably 5 or more and 30 or less, and still more preferably 7 or more and 20 or less. Can be more effective.

  When the acid value is less than 3, the toner charge rises slowly, and image defects such as fogging and scattering may occur before the charge rises. In addition, when the acid value is greater than 35, charge-up particularly in a low-humidity environment becomes prominent, which may cause problems such as a decrease in image density and character scattering.

  In addition, the hydroxyl value (mgKOH / g) of the polar resin used in the present invention is preferably 5 or more and 40 or less, more preferably 10 or more and 35 or less, and still more preferably 15 or more and 30 or less. More effective.

  When the hydroxyl value is less than 5, the toner charge rises slowly, and image defects such as fogging and scattering may occur before the charge rises. In addition, when the hydroxyl value is larger than 40, the reduction of the charge amount becomes remarkable particularly in a high humidity environment, which may cause image defects such as fogging and scattering.

  The “polyester unit” used in the present invention means a part derived from polyester. Specifically, as a component constituting the polyester unit, a divalent or higher valent alcohol monomer component and a divalent or higher carboxylic acid, It means an acid monomer component such as a divalent or higher carboxylic acid anhydride and a divalent or higher carboxylic acid ester.

  The toner of the present invention is characterized in that a component having these polyester units is used as a part of a raw material and a resin having a condensation-polymerized portion is used.

  As a dihydric or higher alcohol monomer component which is a polyester unit component, specifically, as a dihydric alcohol monomer component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0 ) -Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane and other alkylene oxides of bisphenol A Adduct, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-pro Lenglycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, Examples include dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, and hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol monomer component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.

  The divalent or higher carboxylic acid monomer component includes aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or their anhydrides; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid, or their anhydrides. A succinic acid substituted with an alkyl group or an alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof; In particular, isophthalic acid is preferably used because of its high reactivity.

  Other monomers include glycerin, sorbit, sorbitan, and polyhydric alcohols such as oxyalkylene ethers of novolak type phenol resins; trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid and anhydrides thereof, etc. And polyvalent carboxylic acids.

  Among these, in particular, a bisphenol derivative represented by the following general formula (1) is a dihydric alcohol monomer component, and a carboxylic acid component comprising a divalent or higher carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof ( For example, fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) are used as acid monomer components, and resins obtained by condensation polymerization with these polyester unit components have good charging characteristics Therefore, it is preferable.

（式中、Ｒはエチレン又はプロピレン基を示し、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以上１０以下である。）

(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 or more and 10 or less.)

  The toner of the present invention has the weight average particle diameter (D4) of 4.0 μm or more and 9.0 μm or less, so that the effects of the present invention can be exhibited. Preferably, it is 6.0 μm or more and 7.5 μm or less.

  When the weight average particle diameter of the toner is less than 4.0 μm, it is easy to cause charge-up, thereby causing problems such as fogging, scattering, and low image density. In addition, the charging member is easily contaminated during long-term image output, making it difficult to provide a stable high-quality image. Furthermore, not only is it difficult to clean the transfer residual toner remaining on the photosensitive member, but also the toner is easily fused to the photosensitive member.

  On the other hand, if it is larger than 9.0 μm, the fine line reproducibility of minute characters and the like and the image scattering are deteriorated, so that it is not possible to provide a recently desired high-quality image.

  The toner of the present invention preferably has a maximum endothermic peak peak temperature in the range of 50 to 120 ° C. in the endothermic curve in differential thermal analysis (DSC) measurement. More preferably, it is in the range of 55 to 100 ° C, and further preferably in the range of 60 to 75 ° C.

  This maximum endothermic peak is determined by the type of release agent in the toner. When the peak value is in the above range, it is easy to achieve both fixing properties and developability. The use of two or more release agents is also a method suitably used for achieving the present invention, but the maximum peak temperature range should be within the above range.

  When the maximum peak temperature is less than 50 ° C., toner storage stability and developability such as fogging and scattering may be deteriorated.

  On the other hand, when the maximum peak temperature is higher than 120 ° C., the plasticizing effect on the toner is small, and the low-temperature fixability tends to be slightly deteriorated. In addition, when the temperature control of the fixing device is lowered during continuous paper passing, a release agent cannot be satisfactorily interposed between the good fixing member and the toner, and the transfer paper sticks to the fixing member (so-called fixing sticking) phenomenon. It tends to happen.

  The half-value width of the endothermic peak is preferably 15 ° C. or less, and more preferably 7 ° C. or less. When the half width exceeds 15 ° C., since the crystallinity of the release agent is not high, the hardness of the release agent is soft and may promote contamination of the photosensitive member and the charging member.

  Examples of the release agent used in the toner of the present invention include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax, and Fischer Tropish wax, amide wax, higher fatty acid, long chain alcohol, ketone wax, ester wax, and the like. Derivatives such as these graft compounds and block compounds may be mentioned, and distillation may be performed as necessary.

  As a molecular weight of a mold release agent, it is preferable that a weight average molecular weight (Mw) is 300 or more and 1500 or less, and it is more preferable that it is 400 or more and 1250 or less. When the weight average molecular weight is less than 300, the release agent is likely to be exposed on the surface of the toner particles, the photoreceptor, the charging roller, and the charging member are easily contaminated, and image defects such as fogging and fusion are likely to occur. On the other hand, when the weight average molecular weight exceeds 1500, adverse effects such as deterioration of fixing wrapping property, deterioration of low-temperature fixing property, and deterioration of OHT transparency are likely to occur.

  Further, when the weight average molecular weight / number average molecular weight ratio (Mw / Mn) of the release agent is 1.5 or less, the maximum peak of the DSC endothermic curve of the release agent becomes sharper, and the toner particles at room temperature. This is preferable because the mechanical strength of the toner is improved and a sharp melting characteristic is exhibited at the time of fixing.

  The penetration of the release agent is preferably 15 degrees or less, and preferably 8 degrees or less. When the penetration exceeds 15 degrees, the half-width of the endothermic peak of the release agent exceeds 15 degrees, which easily contaminates the photoconductor, the charging member, and the charging member, and fogging, fusion, etc. It is easy to cause image defects.

  The total amount of the release agent contained in the toner is preferably 2.5 to 25.0 parts by mass in 100 parts by mass of the toner. More preferably, it is contained in an amount of 4.0 to 20 parts by mass, and more preferably 6.0 to 18.0 parts by mass.

  If the total amount of release agent is less than 2.5 parts by mass, the release effect at the time of fixing cannot be fully exerted, and the transfer paper can be discharged and loaded when the fixing body becomes low temperature. Not only is it difficult to do this, but also the transfer paper tends to wrap around. On the other hand, when the amount is larger than 25.0 parts by mass, the charge imparting member and the photosensitive member are significantly contaminated by the release agent, and thus problems such as fogging and fusion are liable to occur.

  The toner of the present invention preferably has a number average molecular weight (Mn) of 2000 or more and 50000 or less, more preferably 5000 or more and 40000 or less, and further preferably 10,000 or more and 250,000,000 or less. When the number average molecular weight (Mn) is less than 2000, the elasticity of the toner particles themselves is too low, and high temperature offset is likely to occur. On the other hand, if the number average molecular weight (Mn) is larger than 50000, the elasticity of the toner particles itself tends to be high, and it becomes impossible to cause the release agent to ooze out well on the fixing surface at the time of fixing. It becomes easy to get around.

  The toner of the present invention has a weight average molecular weight (Mw) of preferably 10,000 or more and 1500,000 or less, more preferably 50,000 or more and 1,000,000 or less, and further preferably 100,000 or more and 750,000 or less. If the weight average molecular weight (Mw) is smaller than 10,000, the toner base itself has too low elasticity and tends to cause high temperature offset. On the other hand, if the weight average molecular weight (Mw) is larger than 1500,000, the elasticity of the toner base itself tends to be high, and it becomes impossible to allow the release agent to ooze out well on the fixing surface at the time of fixing. It becomes easy to get around. Also, the fixing gloss tends to be extremely low.

  In order to control the above physical properties, it can be controlled by the reaction temperature and the kind and amount of a polymerization initiator, a crosslinking agent, a chain transfer agent, and a release agent when a resin or a polymerized toner is produced.

  In order for the toner of the present invention to achieve an appropriate gloss, the melt index (MI) value at 125 ° C. is preferably 1 or more and 50 or less, more preferably 3 or more and 40 or less. If the MI value is smaller than 1, the gloss is too low, and if it is larger than 50, a glazed and high gloss image tends to be obtained.

  The glass transition temperature (Tg) of the toner of the present invention is preferably 50 ° C. or higher and 75 ° C. or lower, more preferably 52 ° C. or higher and 70 ° C. or lower, and further preferably 54 ° C. or higher and 65 ° C. or lower. . When the Tg is less than 50 ° C., the storage stability of the toner is deteriorated. Conversely, if it is higher than 75 ° C., the low-temperature fixing performance tends to deteriorate.

  As the binder resin for the toner, polystyrene; a homopolymer of a styrene substitution product such as poly-p-chlorostyrene and polyvinyltoluene; a styrene-p-chlorostyrene copolymer, a styrene-vinyltoluene copolymer, and a styrene-vinyl. Naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Styrene copolymers such as styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; acrylic Resin; Methacrylic resin; Polyvinegar Vinyl; silicone resins; polyester resins; polyamide resin; furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.

  As the main component of the binder resin, a polyester resin and / or a styrene copolymer which is a copolymer of styrene and another vinyl monomer is preferable in terms of developability and fixability.

  As a comonomer for the styrene monomer of the styrenic copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, Monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a substituted product thereof; maleic acid, butyl maleate, methyl maleate, Dicarboxylic acids having a double bond such as dimethyl maleate and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene Vinyl methyl ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

  The styrenic copolymer is preferably cross-linked with a cross-linking agent such as divinylbenzene in order to widen the fixing temperature range of the toner and improve the offset resistance.

  Next, a method for producing toner particles used in the present invention will be described. The toner particles used in the present invention can be produced using a known pulverization method and polymerization method.

  The method for producing toner particles by the polymerization method will be described by exemplifying the suspension polymerization most preferably used among the toner particles produced in the aqueous system of the present invention. A single monomer in which a polymerizable monomer, a colorant, a release agent, and other additives as necessary are uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic disperser. The dosage system is suspended in an aqueous medium containing a dispersion stabilizer. The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction.

  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 or a polyfunctional polymerizable monomer can be 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 Examples include vinyl ethers such as ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, Examples include 2,2′-bis (4- (methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

  In the present invention, the above monofunctional polymerizable monomers are used singly or in combination of two or more, or the above monofunctional polymerizable monomers and polyfunctional polymerizable monomers are combined. use. The polyfunctional polymerizable monomer can also be used as a crosslinking agent.

  As the polymerization initiator used in the polymerization of the polymerizable monomer described above, an oil-soluble initiator and / or a water-soluble initiator is used. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide Side, t- butyl hydroperoxide, di -t- butyl peroxide, peroxide initiators such as cumene peroxide.

  Water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloric acid Salts, sodium azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

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

  As the crosslinking agent used in the toner of the present invention, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl ether, divinyl sulfide, divinyl sulfone and other divinyl compounds; and compounds having three or more vinyl groups. These are used alone or as a mixture.

  As the colorant used in the toner of the present invention, the following yellow / magenta / cyan colorants can be used.

  As the black colorant, carbon black or a magnetic material can be used as a main colorant, and it is one of good modes to adjust the color and the toner resistance by mixing the following coloring materials.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used as pigments. Specifically, C.I. I. Pigment Yellow 3, 7, 10, 12, 13, 14, 15, 17, 23, 24, 60, 62, 74, 75, 83, 93, 94, 95, 99, 100, 101, 104, 108, 109, 110 111, 117, 123, 128, 129, 138, 139, 147, 148, 150, 155, 166, 168, 169, 177, 179, 180, 181, 183, 185, 191: 1, 191, 192, 193 199 or the like is preferably used. Examples of the dye system include C.I. I. solvent Yellow 33, 56, 79, 82, 93, 112, 162, 163, C.I. I. Disperse Yellow 42, 64, 201, 211 etc. are mentioned. By including such a yellow colorant in the toner, a yellow toner can be obtained.

  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, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. Pigment Bio Red 19 is particularly preferable. By including such a magenta colorant in the toner, a magenta toner can be obtained.

  As the cyan colorant, 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. By incorporating such a cyan colorant into the toner, a cyan toner can be obtained.

  A full color toner that forms a full color image can be obtained by combining the black toner, yellow toner, magenta toner, and cyan toner.

  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, OHT 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 binder resin.

  In the toner of the present invention, it is preferable to use a charge control agent in order to keep the toner chargeability stable. The following substances are used for controlling the toner to be negatively charged.

  For example, organometallic compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, resin charge control agents, and the like can be given.

  The following substances are used to control the toner to be positively charged.

  Modified products of nigrosine with nigrosine and fatty acid metal salts, etc .; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Phosphonium salts and other onium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid Acids, ferricyanides, ferrocyanides, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate DOO, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate; resin charge control agent and the like. These can be used alone or in combination of two or more.

  Among these, in order to sufficiently exhibit the effects of the present invention, a metal-containing salicylic acid compound is preferable, and the metal is particularly preferably aluminum or zirconium. As the most preferred control agent, an aluminum salicylate compound is preferred.

  The charge control agent may be used in an amount of 0.01 to 20.00 parts by mass, more preferably 0.50 to 10.00 parts by mass, per 100 parts by mass of the binder resin.

  In the present invention, the use of a lubricant in order to reduce component contamination takes a suitable form. Examples of the lubricant include fluorine resin powder (polyvinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salt (zinc stearate, calcium stearate, etc.) and the like. Of the above, polyvinylidene fluoride is preferably used.

  In the toner of the present invention, in addition to the silica-titania composite particles, inorganic fine particles or resin particles may be added as necessary in order to further improve charging stability, developability, fluidity, transferability, member adhesion suppression, and durability. The toner used in the present invention can be obtained by sufficiently mixing the external additives with a mixer such as a Henschel mixer.

  Examples of the charge controllable particles among the inorganic fine particles include metal oxides (such as tin oxide, titania, zinc oxide, silica, alumina) and carbon black.

  Abrasives include metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, barium sulfate, etc.) , Calcium carbonate, etc.).

  Examples of the fluidity-imparting agent include metal oxides (silica, alumina, titania, etc.), carbon fluoride, and the like. Each of them is more preferably hydrophobized. In particular, as described above, silica, alumina, and titania are preferable from the viewpoint of maintaining good fluidity and chargeability of the toner and high adsorbability on the toner particles of the present invention. Is also a good form.

  The total amount of these inorganic fine particles and silica titania composite particles added to the toner in the present invention is preferably 0.5 parts by mass or more and 4.5 parts by mass or less, and 0.8 parts by mass or more with respect to 100 parts by mass of the toner particles. 3.5 parts by mass or less is more preferable. If the total amount of inorganic fine particles added is less than 0.5 parts by mass, the fluidity of the toner will be insufficient, causing fog deterioration and toner scattering due to a decrease in chargeability, and the effects of the present invention cannot be fully exhibited. . On the other hand, when the total addition amount is more than 4.5 parts by mass, adverse effects such as toner scattering, deterioration of fixability, fusion of the photosensitive member, and reduction of the toner charge amount due to contamination of the charging member occur.

Titania, silica, and alumina preferably added as the inorganic fine particles have a specific surface area of 20 m ² / g or more and 400 m ² / g or less, more preferably 35 m ² / g or more and 300 m ² / g or less, as measured by the BET method. preferably from within the scope the following 50 m ² / g or more 230 m ² / g. If it is less than 20 m ² / g, it is difficult to ensure sufficient fluidity of the toner particles. On the other hand, if it is greater than 400 m ² / g, the rate of change in the presence state of the inorganic fine particles on the toner during continuous paper passing increases and the degree of aggregation of the toner particles increases.

  The inorganic fine particles as the fluidity-imparting agent are silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, and others for the purpose of improving hydrophobicity, chargeability, and transferability. The treatment is preferably performed by using a treating agent such as an organosilicon compound alone or in combination.

  Other inorganic fine particles include an anti-caking agent; a conductivity imparting agent such as zinc oxide, antimony oxide, tin oxide; and a developability improver. The addition amount of these additives is preferably 0.01 parts by weight or more and 2.50 parts by weight or less, and more preferably 0.10 parts by weight or more and 2.00 parts by weight or less with respect to 100 parts by weight of the toner.

  The shape of the toner is preferably close to a sphere. Specifically, the toner has a shape factor of SF-1 of 100 to 150, more preferably 100 to 140, and even more preferably 100 to 130. is there. Moreover, SF-2 is in the range of 100 to 140, more preferably 100 to 130, and still more preferably 100 to 120.

  When the toner shape factor SF-1 exceeds 150 or SF-2 exceeds 140, the toner transfer efficiency decreases, the toner retransfer increases, and the latent image carrier surface wear increases. It becomes easy and is not preferable.

  The toner of the present invention can be used in any system. For example, a high-speed system toner, an oilless fixing toner, a cleaner system toner, and a carrier in a developing unit deteriorated by long-term use are collected in order, and a fresh carrier is obtained. It is applicable to an image forming method using a known one-component development method or two-component development method, such as a toner for a development method that replenishes toner. In particular, since the toner of the present invention has very good transferability and can obtain a stable image over a long period of time, it is suitably used for an image forming method having an intermediate transfer member and an image forming method having a cleaner-less system. be able to.

  When the toner of the present invention is used as a two-component developer, it can be used in any system regardless of whether it is full color or monochrome. For example, two-component developer for auto-refresh image forming method, two-component developer for high-speed system image forming method, two-component developer for oilless fixing image forming method, two-component developer for cleanerless image forming method It can be applied to known developing methods such as a two-component developer for a TACT image forming method and a two-component developer for an image forming method for supplying a replenishing developer to a developing device using an air flow.

  Next, a carrier when the toner of the present invention is used as a two-component developer will be described.

  When the toner of the present invention is used for a two-component developer, the toner is used by mixing with a magnetic carrier. As the magnetic carrier, known magnetic carriers such as magnetic particles themselves, coated carriers in which magnetic particles are coated with a resin, and magnetic material-dispersed resin carriers in which magnetic particles are dispersed in resin particles can be used. Examples of magnetic particles include surface oxidized or unoxidized iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, rare earth metal particles, alloy particles thereof, oxide particles, ferrite, and the like. Can be used.

  The coated carrier obtained by coating the surface of the magnetic carrier particles with a resin is particularly preferable in a developing method in which an AC bias is applied to the developing sleeve. As a coating method, a method in which a coating solution prepared by dissolving or suspending a coating material such as a resin in a solvent is adhered to the surface of the magnetic carrier core particle, and a method in which the magnetic carrier core particle and the coating material are mixed with powder. A conventionally known method can be applied.

  Examples of the coating material on the surface of the magnetic carrier core particle include silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. These are used alone or in plural. The treatment amount of the coating material is preferably 0.1% by mass or more and 30.0% by mass or less (preferably 0.5% by mass or more and 20.0% by mass or less) with respect to the carrier core particles. The volume-based 50% particle size (D50) of these magnetic carrier core particles is preferably 10 μm or more and 100 μm or less, and preferably 20 μm or more and 70 μm or less.

  The volume-based 50% particle size of the present invention was measured with a laser diffraction particle size distribution meter (manufactured by Horiba, Ltd.).

  When the two-component developer is prepared by mixing the toner of the present invention and the magnetic carrier, the mixing ratio is 2% by mass or more and 15% by mass or less, preferably 4% by mass or more and 13% as the toner concentration in the developer. Good results are usually obtained when the content is less than or equal to mass%. If the toner concentration is less than 2% by mass, the image density tends to decrease, and if it exceeds 15% by mass, fogging or in-machine scattering tends to occur.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples, but this does not limit the present invention in any way.

<Production example of polyester resin>
<< Production Example of Polyester Resin 1 >>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 2.75 mol Polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 1.0 mol, isophthal The acid 6.1 mol and the trimet anhydride 0.15 mol were measured. 100 parts by mass of these acids / alcohols and 0.30 parts by mass of potassium titanyl oxalate were placed in a 4-liter 4-neck flask made of glass, and a thermometer, a stirring rod, a condenser and a nitrogen introduction tube were attached and placed in a mantle heater. . In a nitrogen atmosphere, the reaction was performed at 220 ° C., and when the acid value reached 13, the heating was stopped and the mixture was gradually cooled to obtain Resin 1 having a polyester unit component. This resin had a hydroxyl value of 20, Mw of 10,000, Mn4400, and Tg: 67.1 ° C.

<< Production Example of Polyester Resin 2 >>
65.3 parts by mass of terephthalic acid and 18 parts by mass of ethylene glycol were mixed in a 4 liter glass four-necked flask equipped with a thermometer, stirring rod, condenser and nitrogen introduction tube in a mantle heater, and the temperature was 100 ° C. Dissolved, depressurized and dehydrated. Thereafter, after cooling to 50 ° C., 17.2 parts by mass of titanium tetramethoxide was added under a nitrogen atmosphere. Thereafter, the pressure was reduced, and methanol as a reaction product was distilled off to obtain an aromatic carboxylate titanium compound A.

  Next, 2.75 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 1 0.0 mol, 6.1 mol of isophthalic acid, and 0.15 mol of trimetic anhydride were measured. 100 parts by mass of these acids / alcohols and 3.00 parts by mass of aromatic carboxylic acid titanium compound A are put into a glass 4-liter four-necked flask and a thermometer, a stirring rod, a condenser and a nitrogen introducing tube are attached to a mantle heater. I was inside. The reaction was carried out at 220 ° C. in a nitrogen atmosphere, and when the acid value reached 13, heating was stopped and the mixture was gradually cooled to obtain a polyester resin 2 having a polyester unit component. This resin had a hydroxyl value of 20, Mw of 7,650, Mn of 3,500, and Tg: 68.5 ° C.

<Production example of silica-titania composite particles>
<< Production Example of Silica-Titania Composite Particle 1 >>
The nozzles of the silicon tetrachloride gas and the titanium tetrachloride gas are set so that the ratio of the silicon tetrachloride gas and the titanium tetrachloride gas becomes a fine droplet at a flow rate ratio of 70.0: 30.0. It was adjusted and hydrolyzed at a high temperature by being sprayed and introduced into an oxygen-hydrogen flame having a flame temperature of 1500 ° C. to produce silica-titania composite particles, which were cooled and collected by a filter.

  At this time, taking into account the reaction rate difference between silica tetrachloride gas and titania from titanium tetrachloride gas, together with the flow rate ratio of silicon tetrachloride gas and titanium tetrachloride gas introduced into the combustion burner, combustion time and combustion By adjusting the atmosphere, the nozzle position at the time of introducing each gas, and other combustion conditions in combination, physical properties such as the structure of FIG. 1 and the zeta potential of Table 1 were obtained.

  100 parts by mass of the silica-titania composite particles are put into a stirrer, and 18 parts by mass of dimethyl silicone oil (trade name: KF96-100cs: manufactured by Shin-Etsu Chemical Co., Ltd.) are sprayed using a two-fluid nozzle while stirring. And attached to silica-titania composite particles.

  Further, the stirring treatment was continued for 60 minutes, and the silica titania composite particles No. 1 surface-treated with silicone oil were treated. 1 was obtained. Table 1 shows the physical properties of the obtained silica-titania composite particles 1.

<< Production Example of Silica-Titania Composite Particles 2, 3, 4, 5, 6, 7 >>
In the production example of “silica titania composite particles 1”, the ratio of silicon tetrachloride gas and titanium tetrachloride gas was 65.0: 35.0, 55.0: 45.0, 75.0: 25.0, respectively. Except for changing to 85.0: 15.0, 50.0: 50.0, and 90.0: 10.0, the same as “silica titania composite particles 1”, silica titania composite particles 2, 3, 4, 5, 6, 7 were obtained. Table 1 shows the physical properties of the obtained silica-titania composite particles 2, 3, 4, 5, 6, and 7.

<< Production Example of Silica-Titania Composite Particles 8, 9, 10 >>
In the production example of “Silica-Titania Composite Particle 1”, the nozzle position when introducing each of silicon tetrachloride gas and titanium tetrachloride gas was changed to the zeta potential shown in Table 1, and the silica-titania composite was changed. Particles 8, 9, and 10 were obtained. Table 1 shows the physical properties of the obtained silica-titania composite particles.

<< Production Example of Silica-Titania Composite Particle 11 >>
In the production example of “silica titania composite particles 5”, the nozzle position at the time of introducing each of silicon tetrachloride gas and titanium tetrachloride gas was changed to the zeta potential shown in Table 1, and the silica titania composite was changed. Particles 11 were obtained. The physical properties of the obtained silica-titania composite particles 11 are shown in Table 1.

<< Production Example of Silica-Titania Composite Particle 12 >>
In the production example of “silica titania composite particles 3”, the same procedure was performed except that the nozzle position and the flame temperature at the time of introducing each of the silicon tetrachloride gas and the titanium tetrachloride gas were changed to 1700 ° C. Particles 12 were obtained. The physical properties of the obtained silica-titania composite particles 12 are shown in Table 1. As Table 1 shows, the volume resistivity measured in the untreated state of the silica titania composite particles was smaller than that of the silica titania composite particles 3. When the existence ratio of the silica single particles and the titania single particles was measured, the silica titania composite particles 3 was 3.5 frequency%, whereas the silica titania composite particles 12 was 8.5 frequency%. The zeta potential is estimated to be lower in the silica titania composite particles 12 than in the silica titania composite particles 3.

<< Production Example of Silica-Titania Composite Particle 13 >>
In the production example of “silica titania composite particles 5”, silica titania composite particles 13 were obtained in the same manner as the silica titania composite particles 5 except that the flame temperature was changed to 1050 ° C. The physical properties of the obtained silica-titania composite particles 13 are shown in Table 1. As shown in Table 1, the volume resistivity measured in the untreated state of the silica titania composite particles was larger than that of the silica titania composite particles 5. When the silica frequency and the presence ratio of titania single particles were measured, the silica titania composite particle 3 was 3.5 frequency%, whereas the silica titania composite particle 13 was 1.5 frequency%. It is estimated that the specific resistance has increased.

<< Production Example of Silica-Titania Composite Particles 14 and 15 >>
In the production example of “silica titania composite particle 1”, “silica titania composite particle 1” was changed except that dimethyl silicone oil was changed to hexamethyldisilazane and the addition amount thereof was changed to 15 parts by mass and 18 parts by mass, respectively. In the same manner as above, silica titania composite particles 14 and 15 were obtained. The physical properties of the obtained silica-titania composite particles 14 and 15 are shown in Table 1.

<< Production Example of Silica-Titania Composite Particle 16 >>
In the production example of “silica titania composite particle 1”, the ratio of silicon tetrachloride gas to titanium tetrachloride gas is changed to 60.0: 40.0, and the addition amount of dimethyl silicone oil is changed to 15 parts by mass. Except for this, silica titania composite particles 167 were obtained in the same manner as “silica titania composite particles 1”. Table 1 shows the physical properties of the obtained silica-titania composite particles 16.

<< Production Example of Silica-Titania Composite Particle 17 >>
In the production example of “silica titania composite particle 1”, silica was changed in the same manner as “silica titania composite particle 1” except that dimethyl silicone oil was changed to aminopropyltriethoxysilane and the addition amount was changed to 10 parts by mass. Titania composite particles 17 were obtained. The physical properties of the obtained silica-titania composite particles 17 are shown in Table 1.

<< Production Example of Silica-Titania Composite Particle 18 >>
In the production example of “silica titania composite particle 1”, except that the surface treatment was performed with 10 parts by mass of hexamethyldisilazane and then the surface treatment was performed with dimethyl silicone oil, and the addition amount was changed to 15 parts by mass. Silica-titania composite particles 18 were obtained in the same manner as the titania composite particles 1 ″. Table 1 shows the physical properties of the obtained silica-titania composite particles 18.

<< Production Example of Silica-Titania Composite Particle 19 >>
In the production example of “silica titania composite particles 12”, the nozzle position and flame temperature at the time of introducing each of silicon tetrachloride gas and titanium tetrachloride gas were changed to 1600 ° C., and the amount of dimethyl silicone oil added was changed. Except for changing to 10 parts by mass, silica-titania composite particles 19 were obtained in the same manner as “silica-titania composite particles 12”. Table 1 shows the physical properties of the obtained silica-titania composite particles 19.

<< Production Example of Silica-Titania Composite Particle 20 >>
In the production example of “silica titania composite particle 1”, “silica” was used except that the surface treatment was performed with 5 parts by mass of hexamethyldisilazane and then the surface treatment was performed with dimethyl silicone oil and the addition amount was changed to 5 parts by mass. Silica-titania composite particles 20 were obtained in the same manner as the titania composite particles 1 ″. Table 1 shows the physical properties of the obtained silica-titania composite particles 20.

<< Production Example of Silica-Titania Composite Particle 21 >>
In the production example of “silica titania composite particles 20”, after surface treatment with 5 parts by mass of hexamethyldisilazane, surface treatment with dimethylsilicone oil, and the addition amount is changed to 2.5 parts by mass, Silica-titania composite particles 21 were obtained in the same manner as “Silica-titania composite particles 20”. Table 1 shows the physical properties of the obtained silica-titania composite particles 21.

<< Production Example of Silica-Titania Composite Particles 22, 23 >>
In the production example of “silica titania composite particle 1”, silica titania composite was prepared in the same manner as “silica titania composite particle 1” except that the addition amount of dimethyl silicone oil was changed to 23 parts by mass and 27 parts by mass, respectively. Particles 22 and 23 were obtained. The physical properties of the obtained silica-titania composite particles 22 and 23 are shown in Table 1.

<< Production Example of Silica-Titania Composite Particle 24 >>
70.0 parts by mass of silicon tetrachloride gas and 30.0 parts by mass of titanium tetrachloride gas are sufficiently mixed at room temperature. This mixture was introduced by spraying into an oxygen-hydrogen flame so as to be in a fine droplet state, hydrolyzed at a high temperature of 1500 ° C. to produce silica-titania composite particles, cooled and collected by a filter. .

  100 parts by mass of the silica-titania composite particles were put into a stirrer, and 5 parts by mass of hexamethyldisilazane (HMDS) were sprayed using a two-fluid nozzle while stirring to adhere to the silica-titania composite particles.

  Further, the stirring treatment was continued for 60 minutes to obtain silica titania composite particles 24 surface-treated with HMDS. The physical properties of the obtained silica-titania composite particles 24 are shown in Table 1.

<< Production Example of Silica-Titania Composite Particle 25 >>
After metatitanic acid obtained by adding 2.5% by mass of titania sol having a rutile crystal structure as a seed and hydrolyzing it is deiron-bleached, 4 mol / l sodium hydroxide aqueous solution is added to adjust the pH to 9.0, and desulfurization is performed. Processed. Thereafter, the solution was neutralized with 6 mol / l hydrochloric acid to pH 5.5 and washed with filtered water. Water was added to the washed cake to make a slurry of 100 g / L as titanium oxide, and then 6 mol / l hydrochloric acid was added to adjust the pH to 1.2 to perform peptization. After peptization, 45 parts by mass of sodium silicate as SiO ₂ was added to 55 parts by mass of titanium oxide for treatment. Thereafter, the solution was neutralized to pH 6.5 with 4N sodium hydroxide, filtered, washed and dried. Dry metatitanic acid was dehydrated and fired at 300 ° C. to obtain silica-titania composite particles. 100 parts by mass of the silica-titania composite particles were put into a stirrer, and 18 parts by mass of dimethyl silicone oil (trade name: KF96-100cs) was sprayed using a two-fluid nozzle while being agitated to adhere to the silica-titania composite particles. .

  Further, the stirring treatment was continued for 60 minutes to obtain silica titania composite particles 25 whose surface was treated with silicone oil. Table 1 shows the physical properties of the obtained silica-titania composite particles 25.

<< Production Example of Silica-Titania Composite Particle 26 >>
In the production example of “silica titania composite particles 1”, silica titania composite particles 26 were obtained in the same manner as “silica titania composite particles 1” except that the hydrophobization treatment was not performed with dimethyl silicone oil. The physical properties of the obtained silica-titania composite particle 26 are shown in Table 1.

<< Production Example of Toner Particle 1 >>
With respect to 100 parts by mass of the styrene monomer, C.I. I. 16.5 parts by mass of Pigment Blue 15: 3 and 3.0 parts by mass of an aluminum compound of di-tertiary butylsalicylic acid [Bontron E88 (manufactured by Orient Chemical Industries)] were prepared. These were introduced into an attritor (manufactured by Mitsui Mining Co., Ltd.) and stirred at 200 rpm at 25 ° C. for 180 minutes using zirconia beads (140 parts by mass) with a radius of 1.25 mm to prepare a master batch dispersion 1. .

On the other hand, after adding 450 parts by mass of 0.1 M Na ₃ PO ₄ aqueous solution to 710 parts by mass of ion-exchanged water and heating to 60 ° C., 67.7 parts by mass of 1.0 M CaCl ₂ aqueous solution was gradually added. An aqueous medium containing a calcium phosphate compound was obtained.

Master batch dispersion 1 40 parts by mass Styrene monomer 52 parts by mass n-butyl acrylate monomer 19 parts by mass Low molecular weight polystyrene 15 parts by mass (Mw = 3,000, Mn = 1,050, Tg = 55 ° C)
Hydrocarbon wax 9 parts by mass (Fischer-Tropsch wax, maximum endothermic peak = 78 ° C., Mw = 750)
-Polyester resin 1 12 mass parts The said material was heated at 63 degreeC, and it melt | dissolved and disperse | distributed uniformly at 5,000 rpm using TK type | system | group homomixer (made by Tokushu Kika Kogyo). In this, 7.0 parts by mass of a 70% toluene solution of a polymerization initiator 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition is charged into the aqueous medium, and stirred at 12,000 rpm for 10 minutes with a TK homomixer at a temperature of 65 ° C. and in an N ₂ atmosphere to prepare the polymerizable monomer composition. Grained. Thereafter, the temperature was raised to 67 ° C. while stirring with a paddle stirring blade. When the polymerization conversion rate of the polymerizable vinyl monomer reached 90%, a 0.1 mol / liter sodium hydroxide aqueous solution was added. The pH of the aqueous dispersion medium was adjusted to 9. Furthermore, it heated up at 85 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 4 hours. After completion of the polymerization reaction, the residual monomer in the toner particles was distilled off under reduced pressure. After cooling the aqueous medium, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt. The toner particles were separated by filtration and washed with water, and then dried at a temperature of 40 ° C. for 48 hours to obtain cyan toner particles 1. The toner element 1 had a Ti element content of 120 ppm.

<< Production Example of Toner Particles 2 >>
The same procedure as in “Production Example of Toner Particles 1” was performed except that the amount of the polyester resin 1 added was changed to 3 parts by mass to obtain toner particles 2 of the present invention. The toner element 2 had a Ti element content of 30 ppm.

<< Production Example of Toner Particle 3 >>
Toner particles 3 of the present invention were obtained in the same manner as in “Production example of toner particles 1” except that the amount of polyester resin 1 added was changed to 1.5 parts by mass. The toner element 3 had a Ti element content of 15 ppm.

<< Production Example of Toner Particles 4 and 5 >>
In “Production Example of Toner Particles 1”, polyester resin 1 was changed to polyester resin 2 and the addition amounts thereof were changed to 10.5 parts by mass and 12.6 parts by mass, respectively. Toner particles 4 and 5 were obtained. The Ti element contents of the toner particles 4 and 5 were 1000 ppm and 1200 ppm, respectively.

[Example 1]
Toner particles 1: 100 parts by mass, silica-titania composite particles 1: 1.0 parts by mass, and zinc stearate having a number average primary particle diameter of 0.4 μm: 0.3 parts by mass are obtained with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The toner 1 of the present invention was obtained by dry mixing for 5 minutes.

《Image evaluation》
The Canon printer LBP5300 is modified to have the configuration and specifications shown in FIG. 1 (a SUS blade having a thickness of 10 μm is used as the toner regulating member, and a blade bias of −200 V is applied to the toner regulating member with respect to the developing bias. The image was evaluated in each environment. In the evaluation, a toner charged with 175 g of the toner 1 was mounted on the cyan station, and a dummy cartridge was mounted on the other, and image evaluation was performed.

  Image evaluation is 15 ° C./10% RH (low temperature and low humidity environment, hereinafter abbreviated as LL environment) and 32.5 ° C./80% RH (high temperature and high humidity environment, hereinafter abbreviated as HH environment). Went in the environment. The operation of outputting one image with a printing rate of 1% is repeated, and each time the output number reaches 200 sheets, it is left for 1 week in each environment, and then 200 sheets are output repeatedly, finally 4000 sheets The image was output and evaluated by the following method. The evaluation results are shown in Table 2. As the results show, good results were obtained in all evaluations.

(1) Evaluation of fogging In each environment, outputting an image having a white background on the first sheet before and after being left for one week was repeated. Thereafter, the whiteness (reflectance Ds (%)) of the white portion of the printout image measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.) and the whiteness of the transfer paper for the image having all the white background portions. The fog density (%) (= Dr (%) − Ds (%)) was calculated from the difference in degree (average reflectance Dr (%)) to evaluate the fog. In an image having each white background portion, the fog of an image having a white background portion output immediately after endurance of 200 sheets is “immediately after fogging”, and the fog of an image having a white background portion output as the first sheet after being left is referred to as “left-over fog”. did. As for the fogging, the following ranking was performed for the worst ones in each evaluation.

An amberlite filter was used as the filter. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.
A: Less than 0.3% B: 0.3% or more and less than 0.8% C: 0.8% or more and less than 1.3% D: 1.3% or more and less than 2.0%

(Image density stability)
The image density is measured with a color reflection densitometer (for example, X-RITE 404 Amanufactured by X-Rite Co.). Solid images were output one by one before and after being left in each environment, the density difference between the images was measured, and the one with the largest density difference was shown based on the following evaluation criteria.
A: 0.2 or less B: More than 0.2 and 0.3 or less C: More than 0.3

(Image uniformity / image quality)
1) In the image output test, the original photographic image, single-color solid image and halftone image are output one by one before and after being left in each environment, and the image uniformity and image quality are visually observed and transferred. Confirmed the image's harmful effect.
A: Very good (a level at which image unevenness cannot be confirmed with a uniform image)
B: Good (Slight image unevenness can be confirmed, but there is no practical problem at all)
C: Practical use possible (image unevenness can be confirmed, but practically possible level)
D: Not practical (level of image unevenness and practically difficult)

[Examples 2 and 3]
Toners 2 and 3 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 2 and 3. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 3, the fogging in the HH environment was slightly deteriorated. It is presumed that this is because the titania content of the silica-titania composite particles is slightly high, so that the maintenance of charging when left for a long time is slightly inferior.

[Examples 4 and 5]
Toners 4 and 5 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 4 and 5. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 5, the image density stability and the like are slightly deteriorated. This is presumably because the silica-titania composite particles have a slightly higher silica content, so that a slight charge-up occurred when continuously used.

[Comparative Examples 1 and 2]
Toners 6 and 7 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 6 and 7. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, the toner 6 was deteriorated in fogging in the HH environment. This is because the silica titania composite particles have a large titania content, and thus the maintenance of charging when left for a long period of time is an adverse effect. Further, in the toner 7, image density stability and the like deteriorated. This is presumably because the silica-titania composite particles have a slightly higher silica content, so that charge-up occurred when used continuously.

[Examples 6 and 7]
Toners 8 and 9 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 8 and 9. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 8, the fogging in the HH environment was slightly deteriorated. This is presumed to be because the zeta potential measured in an untreated state of the silica-titania composite particles is slightly large, so that the maintenance of charging when left for a long period of time is slightly inferior. In the toner 9, image density stability and the like were slightly deteriorated. This is presumed to be because the zeta potential measured in the untreated state of the silica-titania composite particles is slightly small, and thus the amount of change in the charge amount is slightly generated throughout the durability.

[Comparative Examples 3 and 4]
Toners 10 and 11 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 10 and 11. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 10, the fogging in the HH environment was deteriorated. This is presumed to be due to the fact that the zeta potential measured in the untreated state of the silica-titania composite particles is large, and thus the maintenance of charging when left for a long period of time has deteriorated.

  Further, in the toner 11, image density stability and the like deteriorated. This is presumably because the variation in charge amount was large throughout the durability because the zeta potential measured in the untreated state of the silica-titania composite particles was small.

[Examples 8 and 9]
Toners 12 and 13 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 12 and 13. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, in the toner 12, the fogging in the HH environment was slightly deteriorated. This is presumed to be because the volume resistivity measured in the untreated state of the silica-titania composite particles is slightly small, so that the maintenance of charging when left for a long period of time is slightly inferior.

  In the toner 13, image density stability and the like were slightly deteriorated. This is presumably because the volume specific resistance measured in the untreated state of the silica-titania composite particles is slightly large, and thus the variation in the charge amount is slightly caused through the durability.

[Examples 10 and 11]
Toners 14 and 15 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 14 and 15. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, the toners 14 and 15 were slightly deteriorated as the zeta potential measured in the state in which the fog immediately after the HH environment was subjected to the hydrophobization treatment was decreased. This is because the negative chargeability of the silica titania composite particles increases and the silica titania composite particles tend to agglomerate slightly as the zeta potential measured in the hydrophobized state of the silica titania composite particles decreases. It is estimated that the fluidity of the toner is slightly deteriorated.

[Examples 12 and 13]
Toners 16 and 17 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 16 and 17. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, in toners 16 and 17, the fog immediately after the HH environment slightly deteriorated as the zeta potential measured in the state of being hydrophobized was increased. This is presumably because the charge imparting ability of the silica-titania composite particles to the toner is slightly deteriorated because the zeta potential measured in a state where the silica-titania composite particles are subjected to the hydrophobic treatment is slightly large.

[Examples 14 and 15]
Toners 18 and 19 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 18 and 19. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, in the toner 18, image uniformity, image quality, etc. under low humidity were slightly deteriorated. This is presumably because the resistance measured when the silica-titania composite particles were subjected to a hydrophobic treatment was slightly large, so that the chargeability under low humidity was increased and the transferability was slightly deteriorated.

  In addition, with toner 19, image uniformity, image quality, etc. under high humidity were slightly deteriorated. This is presumably because the transferability was slightly deteriorated because the volume resistance measured in a state where the silica-titania composite particles were subjected to the hydrophobic treatment was slightly increased.

[Examples 16 and 17]
Toners 20 and 21 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 20 and 21. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As shown in the results, in toners 20 and 21, as the degree of hydrophobicity decreased, the fogging immediately after standing in an HH environment and the standing fogging slightly deteriorated. This is presumably because the charge imparting ability of the silica-titania composite particles to the toner slightly deteriorated as the hydrophobicity of the silica-titania composite particles decreased.

[Examples 18 and 19]
Toners 22 and 23 were obtained in the same manner as in Example 1 except that silica-titania composite particles 1 were changed to silica-titania composite particles 22 and 23. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, in the toners 22 and 23, as the degree of hydrophobicity increased, the fogging immediately after being left in both environments and the fogging were slightly deteriorated. This is because as the hydrophobicity of the silica-titania composite particles increases, the amount of the hydrophobizing agent increases, so the silica-titania composite particles tend to aggregate and the toner fluidity slightly deteriorates. Presumed to be.

[Examples 20 and 21]
In Example 1, toner 24 and 25 were obtained in the same manner except that the toner particle 1 was changed to the toner particles 2 and 3. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the results show, in the toner 25, image uniformity, image quality, etc. under LL are slightly deteriorated. This is presumed to be because the charge relaxation between the toners was slightly deteriorated because the Ti content of the toner particles was slightly low.

[Examples 22 and 23]
In Example 1, toner 26 and 27 were obtained in the same manner except that toner particle 1 was changed to toner particles 4 and 5. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 27, the left fogging under HH and the like are slightly deteriorated. This is presumed to be due to the slight loss of charge from the toner when left for a long time because the Ti element content of the toner particles is slightly high.

[Comparative Example 5]
A toner 28 was obtained in the same manner as in Example 1 except that the silica-titania composite particle 1 was changed to the silica-titania composite particle 24. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, in the toner 28, all items deteriorated. When the silica-titania composite particles 26 were observed with a TEM, the silica-titania composite particles 26 did not have the structure shown in FIG. 1 and were in a state where silica and titania were randomly gathered. For this reason, a large amount of titania was present on the surface. Further, 12 frequency% of silica single particles and titania single particles were present. Therefore, even though it is a silica-titania composite particle, it has the same characteristics as the titania particle.For example, the maintenance of charging when left for a long period of time deteriorates, resulting in a bad effect such as deterioration of fog. It is estimated that

Example 24
A toner 29 was obtained in the same manner as in Example 1 except that the silica-titania composite particle 1 was changed to the silica-titania composite particle 25. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, the toner 29 was slightly deteriorated for all items. The silica-titania composite particles 25 were slightly present where the silica was not uniformly coated around the titania, and the silica single particles and the titania single particles were present at 8.5% by frequency. Therefore, although it is a silica-titania composite particle, the same characteristics as the titania particle are slightly developed, for example, the maintenance of charging when left for a long period of time is slightly deteriorated, and the fog is deteriorated. It is presumed that some adverse effects occurred.

Example 25
A toner 30 was obtained in the same manner as in Example 1 except that the silica-titania composite particle 1 was changed to the silica-titania composite particle 26. The same evaluation as in Example 1 was performed using the obtained toner. The evaluation results are shown in Table 2. As the result shows, the toner 30 was slightly deteriorated for all items. This is presumably because the silica-titania composite particles 26 are not hydrophobized, so that the fluidity imparting property to the toner is slightly weak and the charge imparting ability is slightly deteriorated due to moisture absorption.

  1 Main electrode, 2 Upper electrode, 3 Insulator, 4 Ammeter, 5 Voltmeter, 6 Constant voltage device, 7 Measurement sample, 8 Guide ring

Claims (10)

Toner particles containing at least a binder resin and a colorant, and at least silica-titania composite particles,
The silica-titania composite particles are untreated or hydrophobized, and the silica-titania composite particles measured in the untreated state have a zeta potential of −45.0 mV to −20.0 mV, Is 55.0 mass% or more and 85.0 mass% or less,
Toner characterized by the above.   2. The toner according to claim 1, wherein a zeta potential measured in an untreated state of the silica-titania composite particles is −40.0 mV to −25.0 mV.   The silica titania composite particles are hydrophobized, and the zeta potential of the silica titania composite particles measured in the hydrophobized state is -40.0 mV to -20.0 mV. Item 3. The toner according to Item 1 or 2. The silica titania composite particles are hydrophobized, and the volume resistivity of the silica titania composite particles measured in the hydrophobized state is 1.0 × 10 ¹² Ω · m or more and 1.0 × 10 ¹⁴ Ω · The toner according to claim 1, wherein the toner is m or less. The silica titania composite particles have a volume resistivity of 1.0 × 10 ⁴ Ω · m or more and 1.0 × 10 ⁸ Ω · m or less measured in an untreated state. The toner according to any one of claims 1 to 4.   The toner according to claim 1, wherein the silica titania composite particles have a silica content of 65.0% by mass or more and 75.0% by mass or less.   The toner according to claim 1, wherein the silica-titania composite particles are produced by a gas phase method.   The silica-titania composite particles are hydrophobized, and the hydrophobization degree of the silica-titania composite particles measured in the hydrophobized state is 60% by volume or more and 90% by volume or less. The toner according to any one of Items 7 to 7.   The silica-titania composite oxide is hydrophobized, and the hydrophobization degree of the silica-titania composite particles measured in the hydrophobized state is 70 vol% or more and 85 vol% or less. The toner according to any one of 1 to 8.   The toner according to claim 1, wherein the toner particles contain 30 ppm or more and 1000 ppm or less of a titanium element.

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