JP5037825B2 - Toner, image forming method and process cartridge - Google Patents

Description

  The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method or the like.

  The present invention also relates to an image forming method and a process cartridge using an electrophotographic method, an electrostatic recording method or the like.

  In an image forming apparatus that forms a predetermined latent image on an electrostatic latent image carrier such as a photosensitive drum, such as an electrophotographic apparatus or an electrostatic recording apparatus, and forms an image using toner, depending on the type of transfer material used The glossiness (gloss) of the obtained fixed image may change. This is because the surface roughness of the transfer material affects the surface smoothness of the fixed toner image.

  In some cases, a high-gloss image is intentionally obtained using a transfer material having a smooth surface, but even when a transfer material having a different surface property is used, it is often desired to obtain an equivalent gloss. For example, a case where a document made of recycled paper and high-quality paper is created.

  Here, as a means for controlling the gloss to an arbitrary value, there is usually a method of changing the fixing speed and temperature according to the paper type (see, for example, Patent Documents 1 and 2). However, this method often has a problem from the viewpoint of usability and energy saving because the fixing speed is lowered and / or the fixing temperature is increased.

  As another means of controlling the gloss to an arbitrary value, a method for obtaining an image with an appropriate gloss in a wide temperature range by defining a maximum endothermic peak and a molecular weight distribution and further using a toner having specific viscoelastic properties. (See, for example, Patent Documents 3 and 4). However, as a result of detailed investigations by the present inventors, the toners described in these documents can be transferred to any transfer material when different types of transfer materials are used and fixing is performed under the same fixing conditions. However, it is difficult to set the image gloss to a suitable category, and there is still room for improvement.

JP 2003-28045 A Japanese Patent Laid-Open No. 2004-94096 JP 2001-75305 A JP 2004-151638 A

An object of the invention according to the present application is to provide a toner capable of obtaining an image maintaining a gloss within a suitable range without changing the fixing speed and fixing temperature even when different types of transfer materials are used, and an image using the toner. It is an object of the present invention to provide a process cartridge having a forming method and the toner and a toner container containing the toner .

In order to achieve the above object, the present invention has the following features.
That is, a toner having toner particles containing at least a binder resin, a colorant, and a release agent,
The loss tangent (tan δ) of the toner has a minimum value 1 and a maximum value 1 at 70 ° C. or more and less than 110 ° C., and a maximum value 2 at 140 ° C. or more and less than 200 ° C.,
The loss elastic modulus G ″ (140 ° C.) of the toner at 140 ° C. is
1.0 × 10 ⁴ dN / m ² ≦ G ″ (140 ° C.) ≦ 2.0 × 10 ⁵ dN / m ²
And
The average circularity (S) of the toner is 0.960 ≦ S ≦ 0.995,
It is a feature of the invention according to the present application that a toner in which the main component of the binder resin is a vinyl copolymer is used.

  The detailed reason why the present invention achieves the above-mentioned effect is unknown, but is presumed to be as follows.

  Even when different types of transfer materials are used, in order to obtain an image in which the image gloss is maintained in a suitable state without changing the fixing conditions, the followability to the unevenness of the transfer material surface layer in the molten state of the toner is good. Is required. This property has a large correlation with the loss elastic modulus (hereinafter also referred to as G ″), which is a physical property representing the viscosity of the toner. On the other hand, it is also required to suppress the offset to the fixing member in the molten state of the toner. This property has a large correlation with the storage elastic modulus (hereinafter also referred to as G ′), which is a physical property representing the elasticity of the toner.

  By the way, when the thickness of the transfer material changes, the amount of heat taken by the transfer material during toner image fixing changes. In addition, even when the basis weight of the transfer material is the same and the surface unevenness is different, the amount of heat taken by the transfer material at the time of fixing the toner image changes. This is presumably because the specific heat of the air layer generated in the gap between the surface irregularities and the toner image is taken into account. As a result, the total amount of heat given to the toner image before the end of the fixing process increases or decreases depending on the type of transfer material and surface unevenness if the settings of the fixing speed, fixing temperature, fixing pressure, etc. are the same.

  Therefore, from the above, in order to suppress the offset to the fixing member when different types of transfer materials are used under the same fixing conditions, the temperature dependence of G ′ near the temperature at which the toner is melted. Needs to be smaller than the conventional one. This is because the offset to the fixing member occurs in the latter half of the fixing process in which the transfer material is separated from the fixing member, and thus it is necessary to consider the specific heat of the transfer material and the air layer.

  On the other hand, when the fixing condition is G ″, the value of G ″ at a specific temperature that matches the fixing condition may be determined to be a suitable category. The follow-up to unevenness on the surface of the transfer material is related to the first half of the fixing process. At this time, since it is not necessary to consider the specific heat of the transfer material, it is only necessary to focus on the interaction between the fixing member and the toner image. It seems that it is sufficient to control the value of G ″ at a specific temperature.

As a result of intensive studies, the inventors of the present invention need to set the value of G ″ of the toner at 140 ° C. to 1.0 × 10 ⁴ dN / m ² or more and 2.0 × 10 ⁵ dN / m ² or less. I found.

When the loss elastic modulus G ″ (140 ° C.) of the toner at 140 ° C. is less than 1.0 × 10 ⁴ dN / m ² , the toner can be excellent in the followability to the unevenness of the surface layer of the transfer material. Since the image reflects the gloss difference of the material itself, the gloss value cannot be maintained in a suitable category. On the other hand, when G ″ (140 ° C.) exceeds 2.0 × 10 ⁵ dN / m ² In this case, the toner is inferior in the ability to follow the irregularities on the surface of the transfer material, and when a different type of transfer material is used, an image in which the gloss is maintained in a suitable state cannot be obtained.

  Note that the temperature of 140 ° C. is an appropriate temperature at which the toner fixability can be discussed in consideration of other parameters such as the pressure during fixing and the fixing speed in addition to the fixing temperature.

  In the toner according to the present invention, the loss tangent tan δ (= G ″ / G ′), which is the ratio of the loss elastic modulus G ″ to the storage elastic modulus G ′, is a maximum value (maximum value 1) at 70 ° C. or more and less than 110 ° C. ) And a minimum value (minimum value 1). The maximum value 1 appearing in the region of 70 ° C. or higher and lower than 110 ° C. is preferably the first maximum value of the tan δ curve in the temperature range of 40 ° C. or higher and 200 ° C. or lower.

  The maximum value 1 of tan δ in this temperature range corresponds to the temperature at which the binder resin transitions from a glass state to a thermally deformable state, and the micro Brownian motion of the polymer chain constituting the binder resin at that temperature. It suggests that it is becoming active.

  Further, the minimum value 1 of tan δ in this temperature range indicates that the binder resin is in a state of flowing and deforming easily even when no force is applied from the outside at that temperature, and the release agent component in the toner is stained. It suggests that it is easy to put out. Therefore, it is preferable that the temperature when tan δ takes the maximum value 1 is lower than the temperature when tan δ takes the minimum value 1.

  If the temperature at which tan δ takes a maximum value of 1 is less than 70 ° C., the toner particles are easily deformed and damaged by frictional heat between the charging member and the developing member, so that there is no problem as an initial image. However, it is not preferable because the toner is inferior in durability. Specifically, the initial image gloss cannot be suitably maintained by continuous printing, and toner particle adhesion (fogging) to a non-image portion occurs, which is not preferable. Further, when the temperature at which tan δ takes the minimum value 1 exceeds 110 ° C., the exudation of the wax as the release agent is not effectively performed, and the toner image is not sufficiently fixed to the transfer material. Absent.

  Further, it is necessary that the tan δ has a maximum value at 140 ° C. or more and less than 200 ° C. (hereinafter, the maximum value in this temperature range is referred to as a maximum value 2).

  In view of the fact that there is generally no significant change in the region where the loss modulus G ″ exceeds 140 ° C., tan δ has a maximum value of 2 in this temperature range. This shows that the storage elastic modulus G ′ that has decreased is near the temperature at which the maximum value of 2 is reached, and that the rate of decrease has become moderate, that is, the above-mentioned “near the temperature at which the toner is in a molten state”. This corresponds to “the temperature dependence of G ′ is smaller than that of the conventional one”.

  When the maximum value 2 does not appear in the above temperature range, G ′ continues to decrease monotonously as the temperature rises. When different types of transfer materials are used under the same fixing conditions, the image gloss is reduced. It becomes impossible to set it in a suitable category.

  In the present invention, G ″ (140 ° C.) and tan δ are determined by the following method.

ARES (Rheometric Scientific F.E. Co., Ltd.) was used as a measuring device. Under the following conditions, storage elastic modulus G ′, loss elastic modulus G ″ and tan δ were measured in a temperature range of 40 ° C. or higher and 200 ° C. or lower.
Measurement jig: A circular parallel plate having a diameter of 8 mm is used. A shallow cup corresponding to a circular parallel plate is used on the actuator side. The gap between the bottom of the shallow cup and the circular plate is about 2 mm.
Sample to be measured: The toner is used after being pressure-molded so as to be a disk-shaped sample having a diameter of about 8 mm and a height of about 2 mm.
Measurement frequency: 6.28 radians / second Measurement strain setting: The initial value is set to 0.1%, and then the measurement is performed in the automatic measurement mode.
-Sample extension correction: Adjust in automatic measurement mode.
Measurement temperature: The temperature is raised from 40 ° C. to 200 ° C. at a rate of 2 ° C. per minute.

  The loss elastic modulus G ″ at 140 ° C. when the loss elastic modulus G ″ was measured in the temperature range of 40 ° C. to 200 ° C. by the above method was defined as G ″ (140 ° C.).

  An example of the storage elastic modulus G ′ and loss elastic modulus G ″ of the toner of the present invention is shown in FIG.

  An example of the loss tangent (tan δ) of the toner of the present invention is shown in FIG.

  In the present invention, it is necessary to use a vinyl copolymer as a main component of the binder resin. In the present invention, the main component is 50% by mass or more, and more preferably 80% by mass or more. Specifically, a copolymer formed from a monomer selected from styrene or a styrene monomer; or a monomer selected from styrene or a styrene monomer and an acrylate ester monomer Or a copolymer of a monomer selected from styrene or a styrene monomer and a methacrylic acid ester monomer. As a specific monomer, the polymerizable monomer illustrated later can be used as a polymerizable monomer which can be used for a suspension polymerization method.

  By using this compound, even when different transfer materials are used, image quality such as fine line reproducibility and density stability of the image can be maintained in a suitable state. The detailed reason is unknown, but the transfer properties are the same even when the transfer material is different due to the comprehensive action of the physical properties of the vinyl copolymer such as charging characteristics, environmental stability, and brittleness. This is presumed to be at a level.

  Next, preferred embodiments of the toner of the present invention will be described.

  In the present invention, the average circularity of the toner is preferably 0.960 or more and 0.995 or less. The average circularity seems to function as an index representing the thermal conductivity of the toner image during the fixing operation. That is, when the average circularity of the toner is close to 1.000, there are less voids between the toner particles in the unfixed image, and heat is easily transmitted uniformly to the entire toner particles. On the other hand, when the toner particles are distorted, the gaps between the toner particles in the unfixed image vary, and the heat transfer to the toner particles becomes non-uniform so that fixing defects are likely to occur. When the surface of the fixed image is rubbed, the toner image is easily peeled off.

  The influence of the toner particle shape on the fixed image becomes more prominent when a film fixing device in which a heat source is brought into contact with the toner image through a film is used as the fixing device. This seems to be because the film fixing device has a smaller heat capacity of the heating member than the heat roll fixing device.

  The average circularity in the present invention is used as a simple method for quantitatively expressing the shape of particles. In the present invention, a flow particle image analyzer “FPIA-1000” manufactured by Toa Medical Electronics was used to measure a particle group having a circle equivalent diameter of 3 μm or more. The circularity (ai) of each particle was determined by the following formula (1), and the total roundness of all particles measured as shown by the following formula (2) was divided by the total number of particles (m). The value is defined as the average circularity (a).

  In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle and then calculates the average circularity, and the circularity is 0.40 or more depending on the circularity obtained. A calculation method is used in which 1.00 or less is divided into 61 divided classes, and the average circularity is calculated using the center value and frequency of the dividing points. However, the error of the average circularity obtained from the calculation formula that directly uses the average circularity value calculated by this calculation method and the circularity of each particle described above is very small and can be substantially ignored. is there. Therefore, in the present invention, the concept of the calculation formula that directly uses the circularity of each particle described above is used for the reason of handling data such as shortening of the calculation time and simplification of the calculation formula, and a partial change is made. Such a calculation formula may be used.

  Measuring means are as follows. A dispersion is prepared by dispersing 5 mg of toner in 10 ml of water in which about 0.1 mg of a surfactant (alkylbenzene sulfonate) is dissolved, and the dispersion is irradiated with ultrasonic waves (20 kHz, 50 W) for 5 minutes for dispersion. The liquid concentration is set to 5000 / μl or more and 20,000 / μl or less, and measurement is performed by the above-described apparatus to determine the average circularity of a particle group having an equivalent circle diameter of 3 μm or more.

  The average circularity in the present invention is an index of the degree of unevenness of the developer, and is 1.000 when the developer is a perfect sphere, and the circularity becomes smaller as the surface shape becomes more complicated.

  In this measurement, the reason for measuring the circularity only for the particle group having an equivalent circle diameter of 3 μm or more is as follows. The particle group having an equivalent circle diameter of less than 3 μm includes a large number of particle groups of external additives that exist independently of the toner particles. Therefore, when the object to be measured is expanded to less than 3 μm, the effect of the toner particles This is because it is difficult to accurately estimate the circularity of the group.

  In the present invention, it is preferable that the toner has a release agent, and the content of the release agent with respect to 100 parts by mass of the binder resin is 2 parts by mass or more and 20 parts by mass or less. When the toner contains an appropriate amount of the release agent, it is possible not only to maintain the image gloss on different transfer materials in a suitable state but also to control the gloss appropriately. Also, toner adhesion on the fixing member or the like can be effectively suppressed.

  When the content of the release agent with respect to 100 parts by mass of the binder resin is less than 2 parts by mass, the effect of adding the release agent is not sufficiently exhibited, and the fixing member is contaminated with toner with use over a long period of time. It is not preferable. When the content of the release agent with respect to 100 parts by mass of the binder resin exceeds 20 parts by mass, the toner is inferior in impact resistance, and the developing member is easily contaminated with long-term use.

  The release agent usable in the toner of the present invention includes paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof; montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method; polyethylene and Derivatives thereof: natural waxes such as carnauba wax and candelilla wax, and derivatives thereof. Examples of the derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products.

  Preferable release agents that can be used in the present invention include ester waxes belonging to the following formulas (I) to (V).

（式中、ａ及びｂは０以上４以下の整数であり、ａ＋ｂは４である。Ｒ₁及びＲ₂は炭素数が１以上４０以下の有機基である。ｍ及びｎは０以上４０以下の整数であり、ｍとｎは同時に０になることはない。）

(In the formula, a and b are integers of 0 or more and 4 or less, and a + b is 4. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms. M and n are 0 or more and 40 or less. (M and n are not 0 at the same time.)

（式中、ａ及びｂは０以上３以下の整数であり、ａ＋ｂは１以上３以下である。Ｒ₁及びＲ₂は炭素数が１以上４０以下の有機基である。Ｒ₃は水素原子または炭素数が１以上の有機基である。ｋは１以上３以下の整数であり、ａ＋ｂ＋ｋ＝４である。ｍ及びｎは０以上４０以下の整数であり、ｍとｎが同時に０になることはない。）

(In the formula, a and b are integers of 0 or more and 3 or less, a + b is 1 or more and 3 or less. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms. R ₃ is a hydrogen atom. Or an organic group having 1 or more carbon atoms, k is an integer of 1 to 3, and a + b + k = 4, m and n are integers of 0 to 40, and m and n are simultaneously 0. Nothing.)

（式中、Ｒ₁及びＲ₃は炭素数１以上４０以下の有機基であり、Ｒ₁とＲ₃は同じものであっても異なっていても良い。Ｒ₂は炭素数１以上４０以下の有機基を示す。）

(In the formula, R ₁ and R ₃ are organic groups having 1 to 40 carbon atoms, and R ₁ and R ₃ may be the same or different. R ₂ has 1 to 40 carbon atoms. Indicates an organic group.)

（式中、Ｒ₁及びＲ₃は炭素数１以上４０以下の有機基であり、Ｒ₁とＲ₃は同じものであってもなくてもよい。Ｒ₂は炭素数１以上４０以下の有機基を示す。）

(In the formula, R ₁ and R ₃ are organic groups having 1 to 40 carbon atoms, and R ₁ and R ₃ may or may not be the same. R ₂ is an organic group having 1 to 40 carbon atoms. Group.)

（式中、ａは０以上４以下の整数であり、ｂは１以上４以下の整数であり、ａ＋ｂは４である。Ｒ₁は炭素数１以上４０以下の有機基である。ｍ及びｎは０以上４０以下の整数であり、ｍとｎが同時に０になることはない）

(In the formula, a is an integer of 0 or more and 4 or less, b is an integer of 1 or more and 4 or less, and a + b is 4. R ₁ is an organic group having 1 to 40 carbon atoms. M and n Is an integer between 0 and 40, and m and n are not 0 at the same time)

More preferable examples include the following compounds.
(1) CH ₃ (CH ₂ ) ₂₀ COO (CH ₂ ) ₂₁ CH ₃
(2) CH ₃ (CH ₂ ) ₁₇ COO (CH ₂ ) ₉ OOC (CH ₂ ) ₁₇ CH ₃
(3) CH ₃ (CH ₂ ) ₁₇ OOC (CH ₂ ) ₁₈ COO (CH ₂ ) ₁₇ CH ₃

  The means for obtaining the toner according to the present invention will be described below.

  In order to obtain a toner having suitable G ″ (140 ° C.) and tan δ values according to the present invention, there is a method of adjusting the molecular weight distribution of the binder resin. In particular, gel permeation chromatography (GPC). The method of adjusting the weight average molecular weight (Mw) in the measurement is effective, specifically, adjusting the reaction temperature at the time of synthesizing the binder resin, making the initiator type and the initiator addition amount suitable, etc. A method is mentioned.

  Viscosity and elasticity can also be improved by providing a rough cross-linked structure in the binder resin and making the temperature gradient of G ′ near the fixing temperature gentle. Specifically, a compound having a molecular weight of about 200 to 300 and having double bonds at both ends is introduced as a cross-linking component, or a metal compound is added at the initial stage of the polymerization reaction in the toner production by the polymerization method, so For example, a weak metal cross-linking reaction is allowed to proceed.

  Although the toner according to the present invention can be produced by a pulverization method, the toner particles obtained by this pulverization method are generally indefinite shape, and the average circularity which is a preferable requirement of the toner according to the present invention is high. In order to obtain a physical property of 0.960 or more, it is necessary to perform mechanical / thermal or some treatment.

  Therefore, in the present invention, the toner particles are preferably produced in water, and more preferably produced by a polymerization method. Examples of the toner production method by polymerization include a direct polymerization method, a suspension polymerization method, an emulsion polymerization method, an emulsion association polymerization method, and a seed polymerization method. Among these, the balance between the particle size and the particle shape is balanced. In view of easiness, it is particularly preferable to produce by suspension polymerization. In this suspension polymerization method, a monomer composition is prepared by uniformly dissolving or dispersing a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives) in the polymerizable monomer. Then, the monomer composition is dispersed in a continuous layer containing a dispersion stabilizer (for example, an aqueous phase) by using an appropriate stirrer, and a polymerization reaction is performed to have a desired particle size. Toner is obtained. When the toner is produced by this suspension polymerization method, since the individual toner particle shapes are almost spherical, it is easy to obtain a toner satisfying the requirement that the average circularity is 0.960 or more. Further, the toner produced by the suspension polymerization method has a relatively uniform charge amount distribution, and thus has high transferability.

  Further, a toner having a core-shell structure can be obtained by adding a polymerizable monomer and a polymerization initiator to the fine particles obtained by suspension polymerization to provide a surface layer.

  When the toner according to the present invention is produced by a polymerization method, examples of the polymerizable monomer constituting the monomer composition to be used include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate Monomers: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacryl Acid fe Le, dimethylaminoethyl methacrylate, methacrylic acid ester Ruitan monomers such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination.

  In the production of the polymerized toner according to the present invention, a resin may be added to the monomer composition for polymerization. For example, hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, nitrile groups, etc. that cannot be used because monomers are water-soluble and dissolve in aqueous suspension to cause emulsion polymerization. When it is desired to introduce the monomer component contained in the toner, it may be in the form of a copolymer such as a random copolymer of these and a vinyl compound such as styrene or ethylene, a block copolymer, or a graft copolymer, or It can be used in the form of a polycondensate such as polyester or polyamide, a polyaddition polymer such as polyether or polyimine.

  When using a resin having such a polar functional group, the number average molecular weight is preferably 5,000 or more. Since resins having a polar functional group tend to concentrate near the surface, the number average molecular weight is less than 5,000, especially 4,000 or less, and this polymer tends to have a bad influence on developability and blocking resistance. It is not preferable. As the polar resin, a polyester resin is particularly preferable.

  In addition, the following resins may be added to the monomer composition for the purpose of improving the dispersibility and fixing properties of the material, or the image characteristics. For example, homopolymers of styrene such as polystyrene and polyvinyltoluene and substituted products thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-methacrylic acid Ethyl acetate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethyl methacrylate ethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer Polymer, styrene Styrene copolymers such as butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, Polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, etc. alone Or it can be used in combination.

  As addition amount of these resin, 1 to 20 mass parts is preferable with respect to 100 mass parts of polymerizable monomers. If it is less than 1 part by mass, the effect of addition is small, and if it exceeds 20 parts by mass, it is difficult to design various physical properties of the polymerized toner.

  Furthermore, if a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained. it can.

  In both the polymerization method and the pulverization method, the glass transition temperature (Tg) of the binder resin is preferably 40 ° C. or more and 70 ° C. or less, more preferably 45 ° C. or more and 65 ° C. or less, and 55 ° C. The range of 65 ° C. or higher is more preferable. These may be used alone or in general so that the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-p139-192 (manufactured by John Wiley & Sons) is 40 ° C. or higher and 70 ° C. or lower. It is used by appropriately mixing the monomer. When the theoretical glass transition temperature is less than 40 ° C., problems are likely to occur in terms of storage stability and durability stability of the toner, and when it exceeds 70 ° C., the fixing point of the toner is increased. In particular, in the case of a color toner for forming a full-color image, the color mixing property at the time of fixing each color toner is lowered and the color reproducibility is poor, which is not preferable.

  The Tg of the toner described above was determined by the following method.

  Tg was defined as Tg at the intersection of the baseline before the endothermic peak, the baseline between the baseline after the endothermic peak, and the rising curve from the DSC curve at the second temperature elevation after the sample was once heated and cooled.

  The toner of the present invention contains a colorant in order to impart coloring power. Examples of the organic pigment or dye preferably used in the present invention include the following.

  As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, a basic dye lake compound, or the like can be used. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  As organic pigments or dyes as magenta colorants, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds are used. . Specifically, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

  As the black colorant, carbon black or a color toned to black using the yellow / magenta / cyan colorant can be used.

  These colorants can be used alone or mixed and further used in the form of a solid solution. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  The colorant is used by adding 1 part by mass or more and 20 parts by mass or less to 100 parts by mass of the binder resin.

  In the present invention, when a toner is obtained using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and water phase transfer property of the colorant, and preferably a material that does not inhibit surface modification, for example, polymerization inhibition. It is better to apply a hydrophobizing treatment. In particular, dyes and carbon blacks have many polymerization inhibiting properties, so care must be taken when using them. A preferable method for surface-treating the dye system includes a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system.

  Carbon black may be treated with a substance that reacts with the surface functional groups of carbon black, such as polyorganosiloxane, in addition to the same treatment as the above dye.

  In the case of a color toner, it is desirable to select and use a disazo yellow pigment, a quinacridone magenta pigment, or a phthalocyanine cyan pigment.

  When the polymerization method is used in the present invention, the polymerization initiator used in the production of the toner has a half-life of 0.5 hours or more and 30 hours or less during the polymerization reaction, with respect to 100 parts by mass of the polymerizable monomer. When the polymerization reaction is carried out with an addition amount of 0.5 parts by mass or more and 20 parts by mass or less, a polymer having a maximum between 10,000 and 100,000 in molecular weight is obtained, and the toner has desirable strength and suitable melting characteristics. Can do. Examples of the polymerization initiator include 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, , 1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, and other azo or diazo polymerization initiators; benzoyl peroxide, t-butyl Peroxy 2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, etc. Oxide-based polymerization initiators.

  When the polymerization method is used in the present invention, a crosslinking agent may be added, and a preferable addition amount is 0.001% by mass or more and 15% by mass or less.

  Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture.

  When the polymerization method is used in the present invention, generally, the above-described toner composition, that is, a component necessary for the toner such as a colorant, a release agent, a plasticizer, a charge control agent, and a crosslinking agent and other additions in the polymerizable monomer Add a suitable agent, for example, an organic solvent, a high molecular weight polymer, a dispersing agent, etc. that are added to lower the viscosity of the polymer produced by the polymerization reaction, and use a disperser such as a homogenizer, ball mill, colloid mill, or ultrasonic disperser. The monomer system uniformly dissolved or dispersed is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time as other additives are added 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.

  After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

  In the production of the polymerized toner relating to the image forming method of the present invention, a known surfactant, organic dispersant or inorganic dispersant can be used as a dispersion stabilizer, and the inorganic dispersant is particularly difficult to produce harmful ultra fine powder. Since the dispersion stability is obtained due to the steric hindrance, the stability is not easily lost even if the reaction temperature is changed, and it is easy to wash and hardly adversely affect the toner. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic salts: Inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina can be used.

  These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. A surfactant of 001 parts by mass or more and 0.1 parts by mass or less may be used in combination.

  Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or alkali after completion of the polymerization.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 ° C. or higher and 90 ° C. or lower. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. In order to consume the remaining polymerizable monomer, the reaction temperature may be raised to 90 ° C. or higher and 100 ° C. or lower at the end of the polymerization reaction.

  The polymerized toner particles can be obtained by performing filtration, washing and drying by a known method after the completion of the polymerization. Thereafter, inorganic fine powder may be mixed and adhered to the surface. Moreover, it is one of the desirable forms of this invention to put a classification process in a manufacturing process and to cut coarse powder and fine powder.

  When the toner according to the present invention is produced by a pulverization method, a known method is used. For example, a binder resin, a release agent, a charge control agent, and optionally a component necessary as a toner such as a colorant and other additions. The toner is mixed thoroughly with a mixer such as a Henschel mixer or a ball mill, and then melted and kneaded using a heat kneader such as a heating roll, kneader, or extruder to mix the resins with each other. The toner particles can be obtained by dispersing or dissolving the material, cooling and solidifying, pulverizing, classification, and surface treatment as necessary. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type.

  Furthermore, the toner according to the present invention includes a method of obtaining a spherical toner by atomizing a molten mixture in air using a disk or a multi-fluid nozzle described in JP-B-56-13945, and a suspension polymerization method as a polymerization method. In addition, a dispersion polymerization method in which a toner is directly produced using an aqueous organic solvent that is soluble in the monomer and insoluble in the obtained polymer, or a toner is produced by direct polymerization in the presence of a water-soluble polar polymerization initiator. The toner can also be produced by a method of producing a toner using an emulsion polymerization method typified by a soap-free polymerization method.

  The toner of the present invention may contain a charge control agent in order to stabilize the charge characteristics. As the charge control agent, a known one can be used, and a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is produced by a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, sulfones Examples thereof include a polymer compound having an acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin. However, in the toner of the present invention, the addition of a charge control agent is not essential, and the toner does not necessarily contain a charge control agent by actively utilizing frictional charging with a layer thickness regulating member or developer carrier. There is no.

  In the present invention, the weight average particle diameter (D4) of the toner is preferably 3.0 μm or more and 10.0 μm or less for faithfully developing minute latent image dots, and is 4.0 μm or more and 8.0 μm or less. More preferably it is. In a toner having a weight average particle diameter of less than 3.0 μm, the transfer residual toner on the photosensitive member increases due to a decrease in transfer efficiency, and the image quality deteriorates. Further, when the weight average particle diameter of the toner exceeds 10.0 μm, the characters and the line image are likely to be scattered, and it is difficult to obtain high resolution.

  The weight average particle diameter and number average particle diameter of the toner of the present invention can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Inc.). Specifically, it can be measured as follows. Using a Coulter Multisizer (manufactured by Coulter), an interface (manufactured by Nikka) and a PC 9801 personal computer (manufactured by NEC) are connected to output the number distribution and volume distribution. As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride can be used. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. The measurement procedure is as follows.

  100 ml or more and 150 ml or less of the electrolytic aqueous solution is added, and 2 mg or more and 20 mg or less of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toner particles of 2 μm or more are measured with the Coulter Multisizer using a 100 μm aperture. Calculate the distribution. From this, the weight average particle diameter (D4) and the number average particle diameter (D1) are determined.

  In the present invention, various fine powders generally known as external additives can be added to the toner particle surfaces as necessary.

  As the external additive used in the present invention, known inorganic fine powders or resin particles are used. In order to improve charging stability, developability, fluidity, and storage stability, silica, alumina, titania or a double oxide thereof may be used. It is preferably selected from inorganic fine powders.

  Further, the external additive used in the present invention may be an unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oils, various modified silicone oils, silane cups for the purpose of hydrophobization and chargeability control, as necessary. It can also be treated with a treating agent such as a ring agent, a silane coupling agent having a functional group, other organic silicon compounds, or an organic titanium compound, or in combination with various treating agents.

  As the external addition method, a conventionally known method such as a Henschel mixer can be used.

  Next, an image forming method, an image forming apparatus that implements the method, and a process cartridge will be described with reference to the drawings.

  First, the developing device 7 will be described with reference to FIG.

  In FIG. 2, reference numeral 5 denotes a toner container for storing a non-magnetic toner 4 as a one-component developer, and an electrostatic latent image carrier is provided in an opening extending in the longitudinal direction in the toner container 5. A developing roller 2 as a toner carrying member disposed to face the photosensitive drum 1 is rotatably disposed. In addition, the developing roller 2 is provided horizontally at the opening of the toner container 5 such that the right half circumferential surface shown in the drawing enters the toner container 5 and the left half circumferential surface is exposed outside the toner container 5.

  The regulating blade 3 as a toner regulating member is provided above the developing roller 2 by being supported by a presser metal plate 6, and the vicinity of the free end side of the regulating blade 3 is in surface contact with the outer peripheral surface of the developing roller 2. It is in contact with the state. The contact direction of the regulating blade 3 with respect to the developing roller 2 is a so-called counter (reverse) direction in which the tip end side is located upstream of the rotation direction of the developing roller 2 with respect to the contact portion. The developing roller 2 is in contact with a coating roller 9 for supplying toner.

  As the toner carrying member, an elastic roller can be used, and a developing system in which the toner is coated on the surface of the elastic roller and the like is brought into contact with the surface of the photosensitive member can be used. In general, in a developing method in which a toner carrier and a photoreceptor are in contact with each other, toner is easily damaged or deformed. However, when the toner described in the present invention is used, such a change can be effectively suppressed. preferable.

In this case, development is performed by an electric field acting between the photosensitive member and the elastic roller facing the surface of the photosensitive member via the toner. Therefore, the surface of the elastic roller or the vicinity of the surface has a potential, and it is necessary to have an electric field in a narrow gap between the surface of the photosensitive member and the surface of the toner carrying member. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the middle resistance region to keep the electric field while preventing conduction with the surface of the photoreceptor, or a method of providing a thin insulating layer on the surface layer of the conductive roller. . Further, a conductive resin sleeve in which the side facing the surface of the photoconductor is coated with an insulating material on the conductive roller, or a conductive layer is provided on the side not facing the photoconductor with an insulating sleeve is also possible. . Further, a configuration in which a rigid roller is used as the toner carrying member and the photosensitive member is flexible like a belt is possible. The resistance value of the roller as the toner carrier is preferably in the range of 10 ² Ω · cm to 10 ⁹ Ω · cm.

  When the surface roughness Ra (μm) of the toner carrier is set to be 0.2 or more and 3.0 or less, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. If the surface roughness Ra of the toner carrier exceeds 3.0, it is difficult not only to make the toner layer on the toner carrier thin, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. . Since the toner carrying ability on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, when the surface roughness Ra is smaller than 0.2, it becomes difficult to control the toner coat amount.

  In the present invention, the surface roughness Ra of the toner carrier is based on JIS surface roughness “JIS B 0601 (2001)” using a surface roughness measuring device (“Surfcoder SE-30H” manufactured by Kosaka Laboratory Ltd.). Corresponds to the centerline average roughness measured. Specifically, a 2.5 mm portion as the measurement length a is extracted from the roughness curve in the direction of the center line, the center line of this extraction portion is the X axis, the direction of the vertical magnification is the Y axis, and the roughness curve is When expressed by y = f (x), it means a value obtained by the following formula expressed in micrometers (μm). The cut-off value was λ = 0.8 mm.

  In the present invention, the toner carrier may be rotated in the same direction as the peripheral speed of the electrostatic latent image carrier, or may be rotated in the opposite direction. When the rotation is in the same direction, it is preferable to set the peripheral speed of the toner carrier to be 1.05 times or more and 3.0 times or less than the peripheral speed of the electrostatic latent image carrier.

  When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the electrostatic latent image carrier, the stirring effect received by the toner on the electrostatic latent image carrier is insufficient and good image quality is achieved. I can't hope. On the other hand, when the peripheral speed ratio exceeds 3.0 times, toner deterioration due to mechanical stress and toner adhesion to the toner carrier are generated and promoted, which is not preferable.

As the electrostatic latent image carrier, a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, CdS, ZnO ₂ , OPC, or a-Si is preferably used. Further, the binder resin of the organic photosensitive layer in the OPC photoreceptor is not particularly limited. Of these, polycarbonate resins, polyester resins, and acrylic resins are particularly preferable because they are excellent in transferability and hardly cause toner fusion to the photoreceptor and filming of external additives.

  Next, an image forming method will be described below with reference to the accompanying drawings.

FIG. 3 is a schematic configuration diagram of an example of a toner for carrying out the image forming method of the present invention, a process cartridge having a toner container containing the toner, and a developing device. In FIG. 3, reference numeral 10 denotes an electrostatic latent image. A charging roller, which is a primary charging member that directly contacts the carrier (photosensitive drum) 1 and is charged, 11 to 13 is a bias power source, 15 is a transfer material such as paper, 16 is a transfer member, and 17 is a fixing pressure. The roller, 18 is a fixing heating roller, and 19 is a cleaner. The same members as those in FIG.

  A bias power source 11 is connected to the charging roller 10 so as to uniformly charge the surface of the photosensitive drum 1. The developing device 7 contains a toner 4 in a toner container 5 and includes a developing roller 2 that is a toner carrier that rotates in the direction of an arrow. Further, the regulating blade 3 and the toner 4 which are toner regulating members for regulating the toner and charging are attached to the developing roller 2 and rotated in the direction of the arrow in order to apply the charging to the toner by friction with the developing roller 2. An application roller 9 is also provided. A developing bias power source 13 is connected to the developing roller 2. A bias power source (not shown) is also connected to the application roller 9, and when negatively charged toner is used, a voltage is applied to the negative side of the developing bias, and when positively charged toner is used, a voltage is applied to the positive side of the developing bias. Is set.

  A transfer bias power source 12 having a polarity opposite to that of the photosensitive drum 1 is connected to the transfer member 16.

  As the developing roller 2 which is a toner carrier, a so-called elastic roller having an elastic layer on the surface is preferably used. The hardness of the material of the elastic layer used for the elastic roller is preferably 30 degrees or more and 60 degrees or less (asker-C / load 1 kg).

  The toner coat amount is controlled by a regulation blade 3, which is in contact with the developing roller 2 through a toner layer. The contact pressure between the regulating blade 3 and the developing roller 2 at this time is preferably in the range of 0.05 N / cm to 0.50 N / cm as the linear pressure in the direction of the developing roller 2 bus.

  Incidentally, the linear pressure is a load applied per length of the blade 3, for example, when a load of 1.2 N is applied to the blade 3 having a contact length of 1 m and brought into contact with the developing roller 2, The linear pressure is 1.2 N / m. If the contact pressure between the regulating blade 3 and the developing roller 2 is less than 0.05 N / cm, in addition to controlling the toner coating amount, uniform frictional charging becomes difficult, causing fogging and the like. On the other hand, if the contact pressure between the regulating blade 3 and the developing roller 2 exceeds 0.5 N / cm, the toner particles are subjected to an excessive load, so that the particles are deformed or the toner is fused to the regulating blade 3 or the developing roller 2. Etc. are likely to occur, which is not preferable.

  The free end portion of the regulating blade 3 may have any shape, for example, in addition to a linear cross-sectional shape, an L-shape bent near the tip, a shape swelled in the vicinity of the tip, etc. Are preferably used.

  As the toner regulating member, a material in which a metal elastic body such as stainless steel, steel, phosphor bronze or the like is used as a base material and a resin is adhered or coated on a portion corresponding to the sleeve contact portion is preferably used.

  Furthermore, by applying a DC electric field and / or an AC electric field to the toner regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening action on the toner, and sufficient image density is achieved. A good quality image can be obtained.

  In FIG. 3, the photosensitive drum 1 rotating in the direction of the arrow is uniformly charged by the primary charging member. In this example, the primary charging member is a charging roller 10 that basically includes a central core metal 10b and a conductive elastic layer 10a that forms the outer periphery thereof. The charging roller 10 is brought into contact with one surface of the photosensitive drum 1 serving as an electrostatic latent image carrier with a suppressed pressure, and is driven to rotate as the photosensitive drum 1 rotates.

  As a preferable process condition when using the charging roller 10, the contact pressure of the roller is 0.05 N / cm or more and 5 N / cm or less, and the applied voltage is a DC voltage or a DC voltage superimposed with an AC voltage. Although not particularly limited, when an AC voltage superimposed on a DC voltage is used, AC voltage = 0.5 kVpp to 5 kVpp, AC frequency = 50 Hz to 5 kHz, DC voltage = ± 0.2 kV to ± 1.5 kV or less, and when a DC voltage is used, DC voltage = ± 0.2 kV or more and ± 5 kV or less. In the present invention, an applied voltage of only a DC voltage is preferably used.

  As charging means other than the charging roller 10, there are a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that a high voltage is unnecessary and the amount of ozone generated is reduced as compared with non-contact corona charging. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  Following the electrostatic latent image carrier charging step, for example, an electrostatic latent image corresponding to an information signal is formed on the photosensitive drum 1 by exposure 14 from a light emitting element, and the toner is brought into contact with the developing roller 2 by a toner. The electrostatic latent image is developed and visualized. Further, when combined with a development system that forms a digital latent image on the photosensitive drum 1, it is possible to develop the dot latent image faithfully without disturbing the latent image. The visible image is transferred to the transfer material 15 by the transfer member 16 and is fixed by passing between the fixing heating roller 18 and the fixing pressure roller 17 to obtain a permanent image.

  On the other hand, the untransferred toner remaining on the photosensitive drum 1 without being transferred is collected by a cleaner 19 having a cleaning blade in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

  FIG. 4 shows a schematic configuration diagram of an example of an image forming apparatus that batch-transfers multiple toner images onto a recording material using an intermediate transfer member in the image forming method of the present invention.

  In FIG. 4, 7 is a developing device (7a to 7d are developing devices of black, yellow, magenta, and cyan, respectively), 21 is a light source device, 22 is a laser beam, 23 is a fixing device, 24 is a developing unit, 25 Is an intermediate transfer drum as an intermediate transfer member, 25a is a conductive support, 25b is an elastic layer, 26 is a bias power source, 27 is a transfer material tray, and 28 is a secondary transfer device, which are the same members as in FIGS. Are given the same reference numerals.

  The surface of the photosensitive drum 1 as an electrostatic latent image carrier is brought into contact with a rotatable charging roller 10 to which a charging bias voltage as a charging member is applied while rotating, so that the surface of the photosensitive drum 1 is uniformly primary. The first electrostatic latent image is formed on the photosensitive drum 1 by the laser beam 22 that is charged and emitted from the light source device 21 as an exposure unit. The formed first electrostatic latent image is developed with black toner in a black developing device 7a serving as a first developing device provided in the rotatable developing unit 24 to form a black toner image. The black toner image formed on the photosensitive drum 1 is electrostatically primarily transferred onto the intermediate transfer drum 25 by the action of a transfer bias voltage applied to the conductive support 25a of the intermediate transfer drum 25. Next, a second electrostatic latent image is formed on the surface of the photosensitive drum 1 in the same manner as described above, the developing unit 24 is rotated, and the yellow toner in the yellow developing device 7b as the second developing device is used. Development is performed to form a yellow toner image, and the yellow toner image is electrostatically primary transferred onto the intermediate transfer drum 25 on which the black toner image is primarily transferred. Similarly, the third electrostatic latent image and the fourth electrostatic latent image are rotated as the developing unit 24, and the magenta toner in the magenta developing device 7c as the third developing device and the fourth developing device are used. Development and primary transfer are sequentially performed with cyan toner in the cyan developing device 7d, and a toner image of each color is primarily transferred onto the intermediate transfer drum 25. The multiple toner image primarily transferred onto the intermediate transfer drum 25 is electrostatically applied onto the transfer material 15 by the action of the transfer bias voltage from the secondary transfer device 28 located on the opposite side via the transfer material 15. Secondary transfer is performed at once. The multiple toner image secondarily transferred onto the transfer material 15 is heated and fixed to the transfer material 15 by a fixing device 23 having a fixing pressure roller 17 and a fixing heating roller 18. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by a cleaner 19 having a cleaning blade in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

  In the primary transfer from the photosensitive drum 1 to the intermediate transfer drum 25, a transfer current is obtained by applying a bias from a bias power source 26 to the conductive support 25 a of the intermediate transfer drum 25 serving as a primary transfer device. Is transferred.

  The intermediate transfer drum 25 includes a conductive support 25a that is a rigid body and an elastic layer 25b that covers the surface. As the conductive support 25a, a metal or an alloy such as aluminum, iron, copper, and stainless steel, and a conductive resin in which carbon or metal particles are dispersed can be used. The thing which penetrated the axis | shaft in the center, the thing which gave reinforcement to the inside of a cylinder, etc. are mentioned.

  The elastic layer 25b is not particularly limited, but styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber (NBR), chloroprene rubber, butyl rubber, silicone. Elastomer rubbers such as rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber and norbornene rubber are preferably used. A resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate, and a copolymer or a mixture thereof may be used.

  Further, a surface layer in which lubricant powder having high lubricity and water repellency is dispersed in an arbitrary binder may be provided on the surface of the elastic layer 25b.

  The lubricant is not particularly limited, but various fluororubbers, fluoroelastomers, fluorocarbons and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymers in which fluorine is bonded to graphite or graphite. (ETFE) and fluorine compounds such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), silicone compounds such as silicone resin particles, silicone rubber and silicone elastomer, polyethylene (PE), polypropylene (PP), polystyrene ( PS), acrylic resin, polyamide resin, phenol resin, epoxy resin and the like are preferably used.

  In addition, a conductive agent may be added to the surface layer binder in order to control resistance. Examples of the conductive agent include various conductive inorganic particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle-dispersed resin.

  The multiple toner images on the intermediate transfer drum 25 are secondarily transferred collectively onto the transfer material 15 by the secondary transfer device 28. As the transfer device 28, a non-contact electrostatic transfer means or a transfer roller using a corona charger is used. A contact electrostatic transfer means using a transfer belt can be used.

  Instead of the intermediate transfer drum 25 as an intermediate transfer member used in the image forming apparatus shown in FIG. 4, it is also possible to batch transfer multiple toner images onto a recording material using an intermediate transfer belt. FIG. 5 shows a schematic configuration diagram of an apparatus using an intermediate transfer belt.

  In FIG. 5, 30 is an intermediate transfer belt, 31 is a roller over which the intermediate transfer belt 30 is wound, 32 is a primary transfer roller, 33a is a secondary transfer counter roller, 33b is a secondary transfer roller, 34 to 36 are bias power supplies, 39 Is a cleaning charging member, and the same members as those in FIGS.

  In the configuration of FIG. 5, the toner image formed and supported on the electrostatic latent image carrier (photosensitive drum) 1 passes through the nip portion between the photosensitive drum 1 and the intermediate transfer belt 30, and the primary transfer roller The primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 30 by an electric field formed by a primary transfer bias applied from 32 to the intermediate transfer belt 30.

  A primary transfer bias for sequentially superimposing and transferring the first to fourth color toner images from the photosensitive drum 1 to the intermediate transfer belt 30 is applied from a bias power source 34 with a polarity opposite to that of the toner.

  In the primary transfer process of the first to fourth color toner images from the photosensitive drum 1 to the intermediate transfer belt 30, the secondary transfer roller 33 b and the cleaning charging member 39 can be separated from the intermediate transfer belt 30. .

  Reference numeral 33b denotes a secondary transfer roller, which is supported in parallel with the secondary transfer counter roller 33a and arranged in a state in which it can be separated from the lower surface of the intermediate transfer belt 30.

  When the composite color toner image transferred onto the intermediate transfer belt 30 is transferred to the transfer material 15, the secondary transfer roller 33b is brought into contact with the intermediate transfer belt 30, and the intermediate transfer belt 30 and the secondary transfer roller 33b The transfer material 15 is fed to the contact nip at a predetermined timing, and a secondary transfer bias is applied from the bias power source 36 to the secondary transfer roller 33b. The composite color toner image is secondarily transferred from the intermediate transfer belt 30 to the transfer material 15 by the secondary transfer bias.

  After the image transfer to the transfer material 15 is completed, a cleaning charging member 39 is brought into contact with the intermediate transfer belt 30 and a bias having a polarity opposite to that of the photosensitive drum 1 is applied from a bias power source 35 to the transfer material 15. A charge having a polarity opposite to that of the photosensitive drum 1 is imparted to the toner (transfer residual toner) remaining on the intermediate transfer belt 30 without being transferred. Next, the transfer residual toner is transferred to the photosensitive drum 1 in the vicinity of the nip portion with the photosensitive drum 1 and in the vicinity thereof, whereby the intermediate transfer belt 30 is cleaned.

  The intermediate transfer belt 30 includes a belt-shaped base layer and a surface treatment layer provided on the base layer. The surface treatment layer may be composed of a plurality of layers.

  Rubber, elastomer, or resin can be used for the base layer and the surface treatment layer. For example, as rubber and elastomer, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, acrylonitrile butadiene rubber, Urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, acrylic rubber, silicone rubber, fluorine rubber, polysulfurized rubber, polynorbornene rubber, hydrogenated nitrile rubber and thermoplastic elastomer (for example, polystyrene, polyolefin, One type or two or more types selected from the group consisting of polyvinyl chloride, polyurethane, polyamide, polyester, fluororesin, and the like can be used. However, it is not limited to the above materials. As the resin, a resin such as a polyolefin resin, a silicone resin, a fluorine resin, or a polycarbonate can be used. A copolymer or a mixture of these resins may be used.

  As the base layer, the rubber, elastomer and resin described above can be used in the form of a film. In addition, a material obtained by coating, dipping, or spraying the above-described rubber, elastomer, or resin on one side or both sides of a core layer in the form of a woven fabric, a nonwoven fabric, a thread, or a film may be used.

  Materials constituting the core layer are, for example, natural fibers such as cotton, silk, hemp and wool; recycled fibers such as chitin fiber, alginic acid fiber and regenerated cellulose fiber; semisynthetic fibers such as acetate fiber; polyester fiber and nylon fiber Synthetic fibers such as acrylic fiber, polyolefin fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, polyvinylidene chloride fiber, polyurethane fiber, polyalkyl paraoxybenzoate fiber, polyacetal fiber, aramid fiber, polyfluoroethylene fiber and phenol fiber; carbon fiber One or more selected from the group consisting of inorganic fibers such as glass fibers and boron fibers; metal fibers such as iron fibers and copper fibers can be used. Of course, the material is not limited to the above.

  Further, a conductive agent may be added to the base layer and the surface treatment layer in order to adjust the resistance value of the intermediate transfer belt 30. Although it does not specifically limit as a electrically conductive agent, For example, metal powder, such as carbon, aluminum, and nickel, metal oxides, such as a titanium oxide, and quaternary ammonium salt containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, One kind or two or more kinds selected from the group consisting of polydiacetylene, polyethyleneimine, boron-containing polymer compound, conductive polymer compound such as polypyrrole, and the like can be used. However, it is not limited to the said electrically conductive agent.

  Further, a lubricant may be added as necessary in order to increase the slipperiness of the surface of the intermediate transfer belt 30 and improve the transferability. Although there is no restriction | limiting in particular as this lubricant, The thing similar to the lubricant disperse | distributed to the surface layer on an elastic layer as mentioned above is used preferably.

  Next, a schematic configuration diagram of an apparatus in which toner images of respective colors are respectively formed by a plurality of image forming units and sequentially transferred onto the same transfer material will be described with reference to FIG.

  In FIG. 6, 1a to 1d are electrostatic latent image carriers (photosensitive drums), 19a to 19d are cleaners, 41a to 41d are image forming units, 42a to 42d are latent image forming means, and 43a to 43d are transfer releases. 44a to 44d are primary chargers, 45 is a static eliminator, 46 is a conveyor belt, 7a to 7d is a developing device, 48 is an adsorption charger, 49a to 49d are separation static elimination dischargers, and 50 is a discharge port. 2 to 4 are assigned the same reference numerals.

  In the configuration of FIG. 6, first to fourth image forming units 41 a to 41 d are arranged in parallel, and each image forming unit includes photosensitive drums 1 a to 1 d which are dedicated electrostatic latent image carriers. ing. The photosensitive drums 1a to 1d are provided with latent image forming means 42a to 42d, developing devices 7a to 7d, transfer dischargers 43a to 43d, cleaners 19a to 19d, and primary chargers 44a to 44d on the outer peripheral side thereof.

  With such a configuration, first, for example, a yellow component color latent image in the original image is formed on the photosensitive drum 1a of the first image forming unit 41a by the latent image forming unit 42a. The latent image is made a visible image with yellow toner of the developing device 7a, and is transferred to the transfer material 15 by the transfer discharger 43a.

  As described above, while the yellow image is transferred to the transfer material 15, the second image forming unit 41b forms a magenta component color latent image on the photosensitive drum 1b, and then the magenta toner of the developing device 7b. Visible image. This visible image (magenta toner image) is transferred onto the transfer material 15 that has been transferred by the first image forming unit 41a by the transfer discharger 43b.

  Thereafter, cyan and black images are formed in the third and fourth image forming portions 41c and 41d in the same manner as described above, and the cyan and black colors are superimposed on the same transfer material 15. It is transcribed. When such an image forming process is completed, the transfer material 15 is conveyed to the fixing device 23 to fix the image on the transfer material 15. As a result, a multicolor image is obtained on the transfer material 15. The photosensitive drums 1a to 1d after the transfer are removed from the residual toner by the cleaners 19a to 19d, and are used for subsequent latent image formation.

  In the image forming apparatus, the transfer belt 15 is used to transfer the transfer material 15. In FIG. 6, the transfer material 15 is transferred from the right side to the left side. The color toner images are transferred by the transfer dischargers 43a to 43d in 41a to 41d.

  In this image forming method, a transport belt using a Tetron fiber mesh as a transport means for transporting the transfer material 15 and a thin film such as a polyethylene terephthalate resin, a polyimide resin, and a urethane resin from the viewpoint of ease of processing and durability. A conveyor belt using a dielectric sheet is used.

  When the transfer material 15 passes through the fourth image forming unit 41d, a DC voltage is applied to the charge eliminator 45, the transfer material 15 is discharged, separated from the conveying belt 46, and then enters the fixing device 23 where the image is fixed. It is discharged from the discharge port 50.

  In this apparatus, each of the plurality of image forming units includes an independent electrostatic latent image carrier, and the transfer material is sequentially transferred to the transfer unit of each electrostatic latent image carrier by a belt-type conveying unit. The electrostatic latent image carrier that is common to the image forming unit is provided, and the transfer material is repeatedly sent to the transfer unit of the electrostatic latent image carrier by a drum-type conveyance unit. It may be configured to receive the transfer of each color.

  In the conveyance belt system of FIG. 6, since the volume resistance is high, the conveyance belt increases the charge amount in the process of repeating the transfer several times as in the color image forming apparatus. For this reason, uniform transfer cannot be maintained unless the transfer current is sequentially increased for each transfer. However, since the toner of the present invention has excellent transferability, the charge of the conveyor belt increases every time the transfer is repeated. Thus, the transferability of toner in each transfer can be made uniform with the same transfer current, and a high-quality high-quality image can be obtained.

  Further, FIG. 7 shows a schematic configuration diagram of another example of an apparatus for carrying out the image forming method of the present invention, which will be described below.

  In FIG. 7, 7 is a developing device, 44 is a primary charger, 60 is a transfer drum, 61 is a gripper, 62 is a transfer charger, 63a and 63b are separation chargers, and 64 is a separation guide. The same members as those in FIG.

  In the configuration of FIG. 7, the electrostatic latent image formed on the photosensitive drum 1 by appropriate means (exposure 14) is the first in the developing devices 7a to 7d attached to the developing unit 24 that rotates in the direction of the arrow. In one developing device 7a, the toner image is visualized by toner. The color toner image on the photosensitive drum 1 is transferred by the transfer charger 62 to the transfer material 15 held on the transfer drum 60 by the gripper 61. The transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer is collected by a cleaner 19 having a cleaning blade in contact with the surface of the photosensitive drum 1, and the photosensitive drum 1 is cleaned.

As the transfer charger 62, a corona charger or a contact charger is used. When the corona charger is used as the transfer charger 62, a voltage of −10 kV to +10 kV is applied, and the transfer current is −500 μA or more. +500 μA or less. A holding member is stretched on the outer peripheral surface of the transfer drum 60, and this holding member is formed of a film-like dielectric sheet such as a polyvinylidene fluoride resin film or polyethylene terephthalate. For example, a sheet having a thickness of 100 μm to 200 μm and a volume resistance of 10 ¹² Ω · cm to 10 ¹⁴ Ω · cm is used.

  Next, the developing unit 24 rotates as the second color, and the developing device 7 b faces the photosensitive drum 1. The developing device 7b develops the second toner, and the toner image is also transferred onto the same transfer material 15 as described above.

  Further, the third color and the fourth color are similarly performed. In this way, the transfer drum 60 rotates a predetermined number of times while carrying the transfer material 15, and a toner image of a predetermined number of colors is transferred in a multiple manner. It is preferable to increase the transfer current for electrostatic transfer in order of the first color <second color <third color <fourth color in order to reduce the residual toner remaining on the photosensitive drum 1.

  The multiple transfer material 15 is separated from the transfer drum 60 by the separation chargers 63a and 63b, and the toner image on the transfer material 15 is fixed by the heat and pressure roller fixing device 46 and added and mixed at the time of fixing. As a result, a full-color copy image is obtained.

  FIG. 8 shows another example of the apparatus for carrying out the image forming method of the present invention. Secondary transfer when four color toner images primarily transferred onto the intermediate transfer drum are collectively transferred onto a transfer material. As a means, a schematic configuration diagram of an image forming apparatus using a transfer belt is shown.

In the apparatus shown in FIG. 8, electrostatic latent images formed on the electrostatic latent image carrier (photosensitive drum) 1 by introducing toners of respective colors of black, yellow, cyan, and magenta into the developing devices 7 a to 7 d, respectively. (Formed by exposure 14) is developed, and each color toner image is formed on the photosensitive drum 1. The photosensitive drum 1 has a photoconductive insulating material layer 71b such as a-Se, CdS, ZnO ₂ , OPC, or a-Si, and is rotated in the direction of the arrow by a driving device (not shown). As the photosensitive layer 71a, an amorphous silicon photosensitive layer or a photosensitive member having an organic photosensitive layer is preferably used.

  The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation substance and a substance having charge transport performance in the same layer, or a function-separated type photosensitive layer having the charge generation layer as a component. It may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.

  The binder resin for the organic photosensitive layer is particularly a polycarbonate resin, a polyester resin, or an acrylic resin, and has good transferability and cleaning properties, and poor cleaning, toner fusion to the photoreceptor, and filming of external additives are unlikely to occur.

  In the charging process, there are a non-contact method with the photosensitive drum 1 using a corona charger and a contact type method using a roller or the like, and either one is used, but efficient uniform charging, simplification, low In order to generate ozone, a contact type as shown in FIG. 8 is preferably used.

  The charging roller 10 is basically composed of a central cored bar 10b and a conductive elastic layer 10a formed on the outer periphery thereof. The charging roller 10 is pressed against the surface of the photosensitive drum 1 with a pressing force, and is driven to rotate as the photosensitive drum 1 rotates.

  Preferred process conditions when using the charging roller 10 are the same as those in the apparatus of FIG.

  The toner image on the photosensitive drum 1 is transferred to the intermediate transfer drum 25 to which a voltage (for example, ± 0.1 kV or more and ± 5 kV or less) is applied. The surface of the photosensitive drum 1 after the transfer is cleaned by a cleaner 19 having a cleaning blade.

  The intermediate transfer drum 25 is disposed in parallel with the photosensitive drum 1 so as to be in contact with the lower surface portion of the photosensitive drum 1 and rotates in the counterclockwise direction of the arrow at the same peripheral speed as the photosensitive drum 1. To do.

  The first color toner image formed and supported on the surface of the photosensitive drum 1 passes through the transfer nip where the photosensitive drum 1 and the intermediate transfer drum 25 are in contact with each other, and the transfer nip is applied with the transfer bias applied to the intermediate transfer drum 25. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer drum 25 by the electric field formed in the area.

  If necessary, the surface of the intermediate transfer drum 25 is cleaned by the removable cleaning means 72 after the toner image is transferred onto the transfer material 15. When there is a toner image on the intermediate transfer drum 25, the cleaning means 72 is separated from the surface of the intermediate transfer drum 25 so as not to disturb the toner image.

  The transfer means is disposed by bearing in parallel with the intermediate transfer drum 25 and contacting the lower surface of the intermediate transfer drum 25. The transfer means is, for example, a transfer roller or a transfer belt, and rotates in the clockwise direction of the arrow at the same peripheral speed as that of the intermediate transfer drum 25. The transfer unit 73 may be disposed so as to be in direct contact with the intermediate transfer drum 25, or a belt or the like may be disposed between the intermediate transfer drum 25 and the transfer unit.

  When the transfer means is a transfer roller, the basic structure is a central core metal 25a and a conductive elastic layer 25b formed on the outer periphery thereof.

  Common materials can be used as the intermediate transfer drum and the transfer roller. By setting the volume specific resistance value of the elastic layer of the transfer roller to be smaller than the volume specific resistance value of the elastic layer 25b of the intermediate transfer drum 25, the voltage applied to the transfer roller can be reduced, and the transfer material 15 is excellent. A toner image can be formed and winding of the transfer material 15 around the intermediate transfer drum 25 can be prevented. In particular, the volume specific resistance value of the elastic layer 25b of the intermediate transfer drum 25 is particularly preferably 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller.

  The hardness of the intermediate transfer drum and the transfer roller is measured according to JIS K-6301. The intermediate transfer drum 25 used in the present invention is preferably composed of an elastic layer 25b whose hardness is in the range of 10 degrees or more and 40 degrees or less, while the hardness of the elastic layer of the transfer roller is that of the intermediate transfer drum 25. A material that is harder than the hardness of the elastic layer 25b and has a value of 41 degrees or more and 80 degrees or less is preferable for preventing the transfer material 15 from being wound around the intermediate transfer drum 25. When the hardness of the intermediate transfer drum 25 and the transfer roller is reversed, a concave portion is formed on the transfer roller side, and the transfer material 15 is easily wound around the intermediate transfer drum 25.

  In FIG. 8, a transfer belt 73 is disposed below the intermediate transfer drum 25. The transfer belt 73 is stretched around two rollers arranged in parallel to the axis of the intermediate transfer drum 25, that is, a bias roller 74 and a tension roller 75, and is driven by a driving unit (not shown). Since the transfer belt 73 is configured such that the bias roller 74 side can move in the arrow direction around the tension roller 75 side, the transfer belt 73 can be brought into contact with and separated from the intermediate transfer drum 25 in the arrow direction from below. A desired secondary transfer bias is applied to the bias roller 74 by a bias power source 76 for secondary transfer, while the tension roller 75 is grounded.

Next, as the transfer belt 73, for example, carbon is dispersed in a thermosetting urethane elastomer and the thickness is controlled to about 300 μm and the volume resistivity is 10 ⁸ Ω · cm to 10 ¹² Ω · cm (when 1 kV is applied). In addition, a rubber belt controlled to 20 μm fluororubber and a volume resistivity of 10 ¹⁵ Ω · cm (when 1 kV is applied) is used. The outer diameter is a tube shape with a circumference of 80 × width of 300 mm.

  The above-described transfer belt 73 is applied with a tension extending by about 5% by the above-described bias roller 74 and tension roller 75.

  The transfer belt 73 is rotated with a difference in speed or peripheral speed from the intermediate transfer drum 25. The transfer material 15 is conveyed between the intermediate transfer drum 25 and the transfer belt 73, and at the same time, a bias having a polarity opposite to the frictional charge of the toner is applied to the transfer belt 73 from the bias power source 76, thereby causing the intermediate transfer drum 25. The upper toner image is transferred to the surface side of the transfer material 15.

  As the material of the transfer rotator, the same material as that of the charging roller can be used, and preferable transfer process conditions include a roller contact pressure of 5 g / cm to 500 g / cm and a DC voltage of ± 0. .2 kV or more and ± 10 kV or less.

For example, the conductive elastic layer 74b of the bias roller 74 has a volume resistance of about 10 ⁶ Ωcm to about 10 ¹⁰ Ωcm, such as polyurethane, ethylene-propylene-diene terpolymer (EPDM) in which a conductive material such as carbon is dispersed. Made of elastic body. A bias is applied to the core metal 74a by a constant voltage bias power source. The bias condition is preferably ± 0.2 kV or more and ± 10 kV or less.

Next, the transfer material 15 is conveyed to a fixing device 23 having a basic configuration of a heating member 18 incorporating a heating element such as a halogen heater and an elastic pressure member 17 pressed against the heating member 18 by a pressing force. By passing between the pressure member 18 and the fixing heating member 17, the toner image is heated and pressure-fixed on the transfer material 15.
(Example)

  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.

(Toner Production Example 1)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 70 ° C., and stirred at 10,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) to obtain an aqueous medium. It was.

on the other hand,
Styrene 80 parts by mass n-butyl acrylate 15 parts by mass 1,3-butanediol dimethacrylate 0.3 parts by mass Saturated polyester resin 4.5 parts by mass (Polycondensate of propylene oxide-modified bisphenol A and isophthalic acid,
(Tg = 65 ° C., Mn = 17000, Mw / Mn = 2.4)
C. I. Pigment Blue 15: 3 10 parts by mass The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 70 ° C., and 9 parts by mass of an ester wax mainly composed of stearyl stearate (maximum endothermic peak 67 ° C. in DSC measurement) was added and mixed and dissolved. 3 parts by mass of the agent 2,2′-azobis-2-methylbutyronitrile (10 hour half-life temperature 67 ° C.) was dissolved.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 7 minutes with a TK homomixer in an N ₂ atmosphere at 70 ° C. After a predetermined time,
Styrene 5 parts by mass Aluminum salicylate compound 1 part by mass (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
And the mixture was further stirred at 10,000 rpm for 1 minute.

  Thereafter, the mixture was reacted at 70 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  The particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles) having a weight average particle size of 7.6 μm.

100 parts by mass of the toner particles and 0.7 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g treated with silicone oil and a primary particle size of 12 nm were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd. )) To obtain toner 1.

  Table 1 shows the physical properties of Toner 1.

(Toner Production Example 2)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 60 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo) to obtain an aqueous medium. It was.

on the other hand,
80 parts by mass of styrene 15 parts by mass of n-butyl acrylate 5 parts by mass of saturated polyester resin (polycondensate of propylene oxide-modified bisphenol A and isophthalic acid, T
g = 65 ° C., Mn = 17000, Mw / Mn = 2.4)
1 part by mass of aluminum salicylate compound (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
C. I. Pigment Blue 15: 3 10 parts by mass Ester wax mainly composed of behenyl behenate 14 parts by mass (maximum endothermic peak 72 ° C. in DSC measurement)
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 60 ° C., and 4 parts by mass of a polymerization initiator lauroyl peroxide (10 hours half-life 62 ° C.) was dissolved therein.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring for 7 minutes at 10,000 rpm with a TK homomixer at 60 ° C. in an N ₂ atmosphere. After a predetermined time,
Styrene 5 parts by mass Aluminum salicylate compound 1.7 parts by mass (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
And the mixture was further stirred at 10,000 rpm for 1 minute.

  Thereafter, the mixture was reacted at 60 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  The particles were dried at 45 ° C. for 12 hours to obtain colored particles (toner particles) having a weight average particle diameter of 7.7 μm.

100 parts by mass of the toner particles and 1.3 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g and a primary particle size of 12 nm treated with silicone oil were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd. )) To obtain toner 2. Table 1 shows the physical properties of Toner 2.

(Toner Production Example 3)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 60 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo) to obtain an aqueous medium. It was.

on the other hand,
Styrene 86 parts by mass n-butyl acrylate 14 parts by mass Divinylbenzene 0.5 parts by mass Saturated polyester resin 5 parts by mass (Polycondensate of propylene oxide-modified bisphenol A and isophthalic acid,
(Tg = 65 ° C., Mn = 17000, Mw / Mn = 2.4)
1 part by mass of aluminum salicylate compound (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
C. I. Pigment Blue 15: 3 10 parts by mass Ester wax mainly composed of stearyl stearate 1.5 parts by mass (maximum endothermic peak 67 ° C. in DSC measurement)
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 60 ° C., and 4 parts by mass of a polymerization initiator lauroyl peroxide (10 hours half-life 62 ° C.) was dissolved therein.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring for 7 minutes at 10,000 rpm with a TK homomixer at 60 ° C. in an N ₂ atmosphere. After a predetermined time,
Toluene 5 parts by mass Aluminum salicylate compound 2 parts by mass (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
And the mixture was further stirred at 10,000 rpm for 1 minute.

  Thereafter, the mixture was reacted at 60 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  The particles were dried at 45 ° C. for 12 hours to obtain colored particles (toner particles) having a weight average particle diameter of 7.7 μm.

100 parts by mass of the toner particles and 0.7 parts by mass of titanium dioxide fine powder having a BET value of 150 m ² / g and a primary particle size of 30 nm were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Toner 3 was obtained. Table 1 shows the physical properties of Toner 3.

(Toner Production Example 4)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 60 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo) to obtain an aqueous medium. It was.

on the other hand,
Styrene 83 parts by mass n-butyl acrylate 17 parts by mass Saturated polyester resin 5 parts by mass (Polycondensate of propylene oxide modified bisphenol A and isophthalic acid,
(Tg = 65 ° C., Mn = 17000, Mw / Mn = 2.4)
C. I. Pigment Blue 15: 3 10 parts by mass Fischer-Tropsch wax 22 parts by mass (FT-100, Nippon Seiki Co., Ltd., DSC measurement maximum endothermic peak 88 ° C.)
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 60 ° C., and 4 parts by mass of a polymerization initiator lauroyl peroxide (10 hours half-life 62 ° C.) was dissolved therein.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring for 7 minutes at 10,000 rpm with a TK homomixer at 60 ° C. in an N ₂ atmosphere. After a predetermined time, the reaction was performed at 60 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  The particles were dried at 45 ° C. for 12 hours to obtain colored particles having a weight average particle diameter of 7.7 μm.

For 137 parts by mass of the colored particles,
2 parts by mass of aluminum salicylate compound (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
Are mixed with a blender, melt kneaded with a biaxial extruder heated to 110 ° C., the cooled kneaded product is coarsely pulverized with a hammer mill, and the coarsely pulverized product is jet mill collision type jet mill (manufactured by Nippon Pneumatic Industrial Co., Ltd.). ). The obtained finely pulverized product was classified to obtain toner particles having a weight average particle diameter of 7.7 μm.

100 parts by mass of the toner particles and 0.7 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g treated with silicone oil and a primary particle size of 12 nm were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd. )) To obtain toner 4. Table 1 shows the physical properties of Toner 4.

(Toner Production Example 5)
Example of toner production other than using 14 parts by mass of t-hexyl-peroxypivalate (“Peroxyl PV” manufactured by NOF Corporation) instead of 3 parts by mass of 2,2′-azobis-2-methylbutyronitrile Toner 5 was obtained in the same manner as in Example 1.

  Table 1 shows the physical properties of Toner 5.

(Toner Production Example 6)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 70 ° C., and stirred at 10,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) to obtain an aqueous medium. It was.

on the other hand,
Styrene 91 parts by mass n-butyl acrylate 4 parts by mass Divinylbenzene 0.3 part by mass Saturated polyester resin 4.5 parts by mass (Polycondensate of propylene oxide-modified bisphenol A and isophthalic acid,
(Tg = 65 ° C., Mn = 17000, Mw / Mn = 2.4)
1 part by mass of aluminum salicylate compound (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
C. I. Pigment Blue 15: 3 10 parts by mass The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). The monomer composition was heated to 70 ° C., and 9 parts by mass of an ester wax mainly composed of stearyl stearate (maximum endothermic peak 67 ° C. in DSC measurement) was added and dissolved therein. , 2'-azobis-2-methylbutyronitrile (10 hours half-life temperature 67 ° C) 3 parts by mass was dissolved.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring at 10,000 rpm for 7 minutes with a TK homomixer in an N ₂ atmosphere at 70 ° C. After a predetermined time,
5 parts by mass of styrene was added, and the mixture was further stirred at 10,000 rpm for 1 minute.

  Thereafter, the mixture was reacted at 70 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  The particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles) having a weight average particle size of 7.6 μm.

100 parts by mass of the toner particles and 1.3 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g and a primary particle size of 12 nm treated with silicone oil were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd. )) To obtain toner 6.

  Table 1 shows the physical properties of Toner 6.

(Toner Production Example 7)
(7-1. Synthesis of Toner Binder 7)
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 724 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 276 parts by mass of isophthalic acid and 2 parts by mass of dibutyltin oxide were placed at 230 ° C. at normal pressure. After the reaction for 8 hours, the reaction was performed for 5 hours under a reduced pressure of 10 mmHg or more and 15 mmHg or less. This was cooled to 160 ° C., 32 parts by mass of phthalic anhydride was added and reacted for 2 hours. Furthermore, this was cooled to 80 ° C. and reacted with 188 parts by mass of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate-containing prepolymer (1). Next, 267 parts by mass of this prepolymer (1) and 14 parts by mass of isophoronediamine were reacted at 50 ° C. for 2 hours to obtain a urea-modified polyester (1) having a weight average molecular weight of 64,000.

  In the same manner as above, 724 parts by mass of bisphenol A ethylene oxide 2-mole adduct and 276 parts by mass of terephthalic acid were subjected to polycondensation at 230 ° C. for 8 hours under normal pressure, and then reacted for 5 hours at a reduced pressure of 10 to 15 mmHg. A polyester (a) which was not modified was obtained.

  200 parts by mass of urea-modified polyester (1) and 800 parts by mass of unmodified polyester (a) are dissolved and mixed in 2000 parts by mass of an ethyl acetate / ethyl methyl ketone (MEK) (1/1) mixed solvent, and a toner binder ( An ethyl acetate / MEK solution of 7) was obtained. Part of the mixture was dried under reduced pressure to isolate the toner binder (7). Tg was 62 ° C.

(7-2. Preparation of toner particles)
In a beaker, 300 parts by mass of the ethyl acetate / MEK solution of the toner binder (7), 9 parts by mass of an ester wax mainly composed of stearyl stearate, 1 part by mass of an aluminum salicylate compound (Bontron E-88, Orient Chemical Co., Ltd.) )) And C.I. I. 6 parts by mass of Pigment Blue 15: 3 was added, and the mixture was stirred and dissolved uniformly at 60 ° C. and 12,000 rpm with a TK homomixer. In a beaker, 706 parts by mass of ion-exchanged water, 294 parts by mass of hydroxyapatite 10% suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) and 0.2 parts by mass of sodium dodecylbenzenesulfonate were uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture was then transferred to a Kolben equipped with a stirrer and a thermometer, heated to 98 ° C. to remove the solvent, filtered, washed and dried, then air classified, and the weight average particle size was 6.4 μm. Colored powder (toner particles) was obtained.

100 parts by mass of the toner particles and 2.5 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g and a primary particle size of 12 nm treated with silicone oil were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). ) To obtain toner 7.

  Table 1 shows the physical properties of Toner 7.

(Toner Production Example 8)
3 parts by mass of tricalcium phosphate is added to 900 parts by mass of ion-exchanged water heated to 73 ° C., and stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo) to obtain an aqueous medium. It was.

on the other hand,
Styrene 80 parts by mass n-butyl acrylate 20 parts by mass Divinylbenzene 0.5 parts by mass Ethylene glycol diacrylate 2.1 parts by mass Saturated polyester resin 1.0 part by mass (Polycondensate of propylene oxide-modified bisphenol A and isophthalic acid,
Tg = 62 ° C., Mn = 17000, Mw / Mn = 2.4)
1 part by mass of aluminum salicylate compound (Bontron E-88, manufactured by Orient Chemical Co., Ltd.)
C. I. Pigment Blue 15: 3 10 parts by mass The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.). This monomer composition was heated to 73 ° C., and 0.7 parts by mass of an ester wax mainly composed of stearyl stearate (maximum endothermic peak 67 ° C. in DSC measurement) was added and dissolved therein. 2 parts by mass of a polymerization initiator 2,2′-azobis-2-methylbutyronitrile was dissolved.

The polymerizable monomer system was put into the aqueous medium, and the mixture was granulated by stirring for 7 minutes at 10,000 rpm with a TK homomixer (Special Machine Industries Co., Ltd.) at 73 ° C. and N ₂ atmosphere. . Thereafter, the mixture was reacted at 73 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, hydrochloric acid was added to the suspension cooled to room temperature (25 ° C.) to dissolve the calcium phosphate salt, followed by filtration and washing with water to obtain wet colored particles.

  Next, the particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles) having a weight average particle size of 7.0 μm.

100 parts by mass of the toner particles and 0.7 parts by mass of titanium dioxide fine powder having a BET value of 150 m ² / g and a primary particle size of 30 nm were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Toner 8 was obtained.

  Table 1 shows the physical properties of Toner 8.

(Toner Production Example 9)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 704 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 296 parts by mass of isophthalic acid and 2 parts by mass of dibutyltin oxide were placed at 230 ° C. at normal pressure. After reacting for 5 hours, the reaction was performed under reduced pressure of 10 mmHg to 15 mmHg for 5 hours. This was cooled to 160 ° C., 30 parts by mass of phthalic anhydride was added and reacted for 2 hours. Further, this was cooled to 80 ° C. and reacted with 188 parts by mass of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate-containing prepolymer (2). Next, 267 parts by mass of this prepolymer (2) and 14 parts by mass of isophoronediamine were reacted at 60 ° C. for 2 hours to obtain a urea-modified polyester (2) having a weight average molecular weight of 59000. Tg was 60 ° C.

  100 parts by mass of urea-modified polyester (2) was dissolved and mixed in 200 parts by mass of an ethyl acetate / methyl ethyl ketone (MEK) (1/1) mixed solvent.

  In this solution, 23 parts by mass of an ester wax mainly composed of behenyl behenate and C.I. I. 6 parts by mass of Pigment Blue 15: 3 was added and stirred with a TK homomixer at 70 ° C. and 12000 rpm, and uniformly dissolved and dispersed. In a beaker, 706 parts by mass of ion-exchanged water, 294 parts by mass of hydroxyapatite 10% suspension (Superite 10 manufactured by Nippon Chemical Industry Co., Ltd.) and 0.2 parts by mass of sodium dodecylbenzenesulfonate were uniformly dissolved. Next, the temperature was raised to 73 ° C., and the toner material solution was added and stirred for 10 minutes while stirring at 12000 rpm with a TK homomixer. The mixture was then transferred to a Kolben equipped with a stir bar and a thermometer, heated to 98 ° C. to remove the solvent, filtered, washed, dried, air-classified, and the weight average particle diameter was 6.0 μm. Colored powder (toner particles) was obtained.

100 parts by mass of the toner particles and 0.4 parts by mass of hydrophobic silica fine powder having a BET value of 200 m ² / g and a primary particle size of 12 nm treated with silicone oil were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd. )) To obtain toner 9.

  Table 1 shows the physical properties of Toner 9.

<Examples 1-4 and Comparative Examples 1-5 >
(Image evaluation)
Using the obtained toner 1 to toner 9, image evaluation was performed according to the following method.

  As a forming apparatus, a commercially available laser beam printer LBP-2410 (manufactured by Canon) was used, and the evaluation was performed in an environment of 23 ° C. and 50% RH.

The remodeling points of the evaluation machine are as follows.
(1) The software has been modified so that the monochrome printing mode that can only be performed with a black cartridge can be performed with other colors.
(2) The software was modified so that the fixing speed could be changed to an arbitrary value.

  The image forming speed (developing roller rotation speed, developing drum rotation speed, etc.) is not changed.

  The cartridge used for evaluation was a cyan cartridge. That is, the product toner was extracted from a commercially available cyan cartridge, the inside was cleaned by air blow, and 160 g of the toner according to the present invention was filled for evaluation. In addition, the product toner was extracted from each of the magenta, yellow, and black stations, and evaluation was performed by inserting magenta, yellow, and black cartridges in which the toner remaining amount detection mechanism was disabled.

The following five types were used as transfer materials.
1. Transfer material LETTER size XEROX 4024 paper (plain paper, made by XEROX, 75 g / m ² )
1. Transfer material LETTER-sized HP COLOR LASER paper (color machine paper, manufactured by HEWLET PACKARD, 105 g / m ² )
2. Transfer material LETTER size FOX RIVER BOND paper (BOND paper, manufactured by FOX RIVER, 90 g / m ² )
3. Transfer material LETTER size UNION CAMP GREAT WHITE MULTI PURPOSE paper (recycled paper, made by UNION CAMP, 75 g / m ² )
4. Transfer material A4 size San-Ichi double stamped paper (neutral)
(Plain paper, manufactured by San-Ichi Composite Paper, 70 g / m ² )

  Each of the above five types of transfer materials, a total of 5 sheets, was used as a set, and 1000 sets were printed continuously using a print image as shown in FIG. 1 with a print ratio of 4%. The image forming speed was set to the speed in the plain paper mode.

  The fixing speed was 190 mm / sec for all recording materials.

  The images of the first set, the 100th set, the 500th set, and the 1,000th set were used to perform image evaluation based on the following evaluation criteria.

(Offset resistance)
The evaluation of the offset resistance was performed using an evaluation image of the transfer material 1.

Visually observe whether or not the images of all the solid portions and character portions shown in FIG. 1 are recognized on the transfer material in accordance with the period of the fixing film (whether or not an offset is generated), and evaluated according to the following criteria. went.
A: The occurrence of offset is not recognized.
B: Although no offset is recognized in all solid parts, offset is recognized in the character part.
C: An offset is recognized in the character part, and a slight offset is recognized in all the solid parts.
D: All solids and character parts have an offset.

(Image gloss)
The image gloss was evaluated using the images of the transfer materials 1 to 5.

  For the five solid image portions shown in FIG. 1, the glossiness of the image was measured using a gloss meter PG-3G (manufactured by Nippon Denshoku Industries Co., Ltd.), and the average value was taken as the image glossiness of the transferred image. The incident angle was 75 degrees.

  The above measurement was performed on all images of the first set, and the average gloss value and standard deviation of the first set of images were obtained.

  Similar measurements were performed for the 100th group, the 500th group, and the 1,000th group, and the average value of image gloss and the standard deviation were obtained for each group.

(Image rubbing property)
Evaluation of image rubbing property was performed using an evaluation image of the transfer material 5.

The five solid image portions shown in FIG. 1 were rubbed five times with Sylbon paper applied with a load of 50 g / cm ² , and the arithmetic average value of the image density reduction rate after the rubbing was obtained. Based on the following criteria: evaluated.

The image density was measured using a “Macbeth reflection densitometer” (manufactured by Macbeth).
A: The density reduction rate is less than 2% B: The density reduction rate is 2% or more and less than 5%.
C: Density reduction rate is 5% or more and less than 10%.
D: The density reduction rate is 10% or more.

It is a schematic diagram of the image for evaluation used for evaluation of this invention. It is explanatory drawing of the toner layer control member in the image forming method of this invention. It is a schematic block diagram of an example of the apparatus which implements the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. It is a schematic block diagram of the other example of the apparatus which enforces the image forming method of this invention. 3 is an example of a storage elastic modulus G ′ and a loss elastic modulus G ″ of the toner of the present invention. 3 is an example of a loss tangent (tan δ) of the toner of the present invention.

Explanation of symbols

1 Photosensitive drum (electrostatic latent image carrier)
1a, 1b, 1c, 1d Electrostatic latent image carrier (photosensitive drum)
2 Development roller (toner carrier)
3 Regulating blade (toner regulating member)
4 Non-magnetic toner 5 Toner container 6 Holding sheet metal 7 Developing device 7a Black developing device 7b Yellow developing device 7c Magenta developing device 7d Cyan developing device 9 Application roller 10 Charging roller (primary charging member)
10a Conductive elastic layer 10b Core metal 11 Bias power supply 12 Transfer bias power supply 13 Development bias power supply 14 Exposure 15 Transfer material (paper)
16 Transfer member 17 Fixing pressure roller 18 Fixing heating roller 19 Cleaner 19a, 19b, 19c, 19d Cleaner 21 Light source device 22 Laser beam 23 Fixing device 24 Developing unit 25 Intermediate transfer drum (intermediate transfer member)
25a Conductive support 25b Elastic layer 26 Bias power supply 27 Transfer material tray 28 Secondary transfer device 30 Intermediate transfer belt 31 Roller 32 Primary transfer roller 33a Secondary transfer counter roller 33b Secondary transfer rollers 34, 35, 36 Bias power supply 39 Cleaning Charging members 41a, 41b, 41c, 41d First to fourth image forming portions 42a, 42b, 42c, 42d Latent image forming means 43a, 43b, 43c, 43d Transfer discharger 44 Primary chargers 44a, 44b, 44c, 44d Primary charger 45 Charger 46 Conveyor belt 48 Adsorption chargers 49a, 49b, 49c, 49d Separation discharger 50 Discharge port 60 Transfer drum 61 Gripper 62 Transfer chargers 63a, 63b Separation charger 64 Separation guide 71a Photosensitive layer 71b Photoconductive insulating material layer 72 Cleaning means 7 Transfer means (transfer belt)
74 Bias roller 74a Core metal 74b Conductive elastic layer 75 Tension roller 76 Bias power supply

Claims (8)

A toner having toner particles containing at least a binder resin, a colorant , a release agent, a saturated polyester resin, and an aluminum salicylate compound ,
The loss tangent (tan δ) of the toner has a minimum value 1 and a maximum value 1 at 70 ° C. or more and less than 110 ° C., and a maximum value 2 at 140 ° C. or more and less than 200 ° C.,
The loss elastic modulus G ″ (140 ° C.) of the toner at 140 ° C. is
1.0 × 10 ⁴ dN / m ² ≦ G ″ (140 ° C.) ≦ 2.0 × 10 ⁵ dN / m ²
And
The average circularity (S) of the toner is 0.960 ≦ S ≦ 0.995,
The main component of the binder resin is Ri vinyl copolymer der,
The vinyl copolymer is a copolymer of styrene or a styrene monomer and an acrylate ester monomer,
The saturated polyester resin is a polycondensate of propylene oxide modified bisphenol A and isophthalic acid,
The toner, wherein the aluminum salicylate compound is contained in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin .   With respect to the loss tangent of the toner, the temperature at which the minimum value is 1 is higher than the temperature at which the maximum value is 1, and the minimum value 1 is in the temperature range of 80 ° C. or higher and lower than 110 ° C. The toner according to claim 1, wherein the toner is in a temperature range of The content (A) of the release agent with respect to 100 parts by mass of the binder resin is
The toner according to claim 1, wherein 2 parts by mass ≦ A ≦ 20 parts by mass.   The toner according to claim 1, wherein the toner particles are formed in water. A charging step of charging the electrostatic latent image carrier using a charging member to which a voltage is applied from the outside; a latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier; Toner layer forming step for regulating the toner layer on the toner carrier; development for developing the electrostatic latent image by the toner layer carried on the surface of the toner carrier to form the toner image on the electrostatic latent image carrier A transfer step of transferring a toner image to a transfer material with or without an intermediate transfer member; an image forming method having at least a fixing step of fixing the toner image on the transfer material,
The toner has toner particles containing at least a binder resin, a colorant , a release agent, a saturated polyester resin, and an aluminum salicylate compound ,
The loss tangent (tan δ) of the toner has a minimum value 1 and a maximum value 1 at 70 ° C. or more and less than 110 ° C., and a maximum value 2 at 140 ° C. or more and less than 200 ° C.,
The loss elastic modulus G ″ (140 ° C.) of the toner at 140 ° C. is
1.0 × 10 ⁴ dN / m ² ≦ G ″ (140 ° C.) ≦ 2.0 × 10 ⁵ dN / m ²
And
The average circularity (S) of the toner is 0.960 ≦ S ≦ 0.995,
The main component of the binder resin is Ri vinyl copolymer der,
The vinyl copolymer is a copolymer of styrene or a styrene monomer and an acrylate ester monomer,
The saturated polyester resin is a polycondensate of propylene oxide modified bisphenol A and isophthalic acid,
The image forming method, wherein the aluminum salicylate compound is contained in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin . The image forming method according to claim 5, wherein the toner is a toner according to any one of claims 2 to 4. A process cartridge having toner used in an image forming method using toner and a toner container containing the toner,
The toner has toner particles containing at least a binder resin, a colorant , a release agent, a saturated polyester resin, and an aluminum salicylate compound ,
The loss tangent (tan δ) of the toner has a minimum value 1 and a maximum value 1 at 70 ° C. or more and less than 110 ° C., and a maximum value 2 at 140 ° C. or more and less than 200 ° C.,
The loss elastic modulus G ″ (140 ° C.) of the toner at 140 ° C. is
1.0 × 10 ⁴ dN / m ² ≦ G ″ (140 ° C.) ≦ 2.0 × 10 ⁵ dN / m ²
And
The average circularity (S) of the toner is 0.960 ≦ S ≦ 0.995,
The main component of the binder resin is Ri vinyl copolymer der,
The vinyl copolymer is a copolymer of styrene or a styrene monomer and an acrylate ester monomer,
The saturated polyester resin is a polycondensate of propylene oxide modified bisphenol A and isophthalic acid,
The process cartridge, wherein the aluminum salicylate compound is contained in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin . The process cartridge according to claim 7, wherein the toner is a toner according to any one of claims 2 to 4.

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