JP2012189929A - Toner for electrophotography development, image forming method, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for an electrophotography development which achieves extremely excellent low-temperature fixability, high hot offset resistance properties and adequate storage stability, has high coloring power and hiding power with a low adhesion amount, and can form a high-gloss image, and to provide an image forming method and a process cartridge.SOLUTION: In the toner for the electrophotography which contains at least a binder resin, a coloring agent and a releasing agent, as for the viscoelasticity of the toner, the tangent loss represented by loss modulus (G")/storage modulus (G')=tangent loss (tan δ) has a peak at 80-160 [°C] and has a peak value of 3 or more.

Description

  The present invention relates to a developing toner, an image forming method, and a process cartridge in electrophotography.

Color image formation by full-color electrophotography generally reproduces all colors using four colors including yellow, magenta, cyan, and black, which are three primary colors.
In the general method, first, an electrostatic latent image is formed on a photoconductive layer by passing light from an original through a color separation light transmission filter having a complementary color and toner color relationship.
Next, the toner is held on a support through development and transfer processes.
Subsequently, the above-described steps are sequentially performed a plurality of times, and the toner is superimposed on the same support while aligning the registration, and a final full-color image is obtained by fixing only once.

In color electrophotography that requires several times of development and superimposition of several types of toner images of different colors on the same support as the fixing process, the fixing characteristics that the color toner should have are extremely important. Element.
In other words, the fixed color toner is required to suppress irregular reflection by toner particles as much as possible and to have appropriate glossiness and gloss. In addition, the toner must be a color toner that has transparency that does not interfere with the toner layer of different color tone below the toner layer and has a wide color reproducibility.
For this reason, color toners generally need to have higher heat melting properties and lower viscosity to obtain gloss and transparency than black toners for black and white printing during fixing heating.

  Further, in recent image forming apparatuses, demands for energy saving at the time of toner fixing and image forming apparatuses capable of high-speed processing are increasing, and the toner itself is required to have a property of melting at a low temperature. However, if the melting point of the toner is simply lowered to enable low-temperature fixing, the storage stability of the toner and the adhesion to the carrier surface when agitated with the carrier in the two-component developing device (hereinafter also referred to as “spent”) There is a concern about deterioration of the charge imparting ability of the carrier.

On the other hand, when forming a full color image, four color toner images are formed on a predetermined white recording medium. However, when the recording medium is colored paper, black paper, transparent film or the like in advance, a good color image cannot be obtained only by using the four color toners.
In view of such a problem, a technique has been proposed in which white toner is used as the fifth color toner to form a white background image (see, for example, Patent Document 1).
The white toner is used to form a white base on a colored recording medium such as colored paper or black paper, or to form a white background on a transparent film or the like.

As described above, an excellent concealment characteristic is required in order to exhibit a sufficient function as a substrate. The concealment characteristic means a function of preventing a portion where white toner is fixed from being transmitted through the layer.
In order to obtain a complete white color by fixing the white toner, it is necessary that all incident light is scattered and reflected. When the incident light is transmitted, the concealability is reduced, and the white toner layer The image above is unclear. That is, the toner design for realizing better concealment is required to be more precise than black or color having the property of absorbing light.

In order to improve such concealment properties, various technical proposals have been made in the past.
For example, Patent Document 2 proposes a toner containing aluminum oxide and / or silicon dioxide as a white toner, and Patent Document 3 discloses a white toner having a toner resin of 100 parts by mass, in which at least 50 parts by mass is a polyester resin, and Toner particles containing 65 to 180 parts by mass of rutile TiO ₂ with respect to 100 parts by mass of the toner resin have been proposed, but sufficient concealing properties have not yet been realized.

  The present invention has been made in view of the above prior art, that is, it has both excellent low-temperature fixability, high hot offset resistance, good storage stability, and coloring power even at a low adhesion amount. An object of the present invention is to provide a toner for electrophotographic development, an image forming method, and a process cartridge capable of forming a high gloss image with high hiding power.

The present inventors have intensively studied to solve the above problems.
As a result, in the toner used for electrophotographic development, in the viscoelasticity of the toner, a tangent loss represented by loss elastic modulus (G ″) / storage elastic modulus (G ′) = tangent loss (tan δ) is 80 to 160. By having a peak at [° C.] and having a tangent loss peak value of 3 or more, both excellent low-temperature fixability, high hot offset resistance, and good storage stability, and A new finding has been found that it is possible to provide a toner for electrophotographic development that can form a highly glossy image with a low adhesion amount, high coloring power, and sufficient glossiness even with a white toner. And we have found a new finding that concealment can be obtained.
The present invention has been made based on this. The said subject is solved by the following (1)-(14) of this invention.

(1) A toner for electrophotographic development containing at least a binder resin, a colorant and a release agent,
In the viscoelasticity of the toner, tangential loss represented by loss elastic modulus (G ″) / storage elastic modulus (G ′) = tangent loss (tan δ) has a peak at 80 to 160 [° C.],
The toner for electrophotographic development is characterized in that the peak value of tangent loss is 3 or more.
(2) The toner for electrophotographic development according to (1), wherein the binder resin contains a crystalline polyester resin.
(3) The toner for electrophotographic development according to (1) or (2), wherein the toner contains a fatty acid amide inside.
(4) The toner for electrophotographic development according to (3), wherein the fatty acid amide is N, N′-ethylene-bisstearic acid amide.
(5) The toner for electrophotographic development according to any one of (1) to (4), wherein the colorant is a white pigment.
(6) The toner for electrophotographic development according to (5), wherein the white pigment is an organic white pigment.
(7) The organic white pigment is N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine, for electrophotographic development according to (6) toner.
(8) The toner for electrophotographic development according to any one of (5) to (7), wherein the content of the white pigment is 10 to 70% by mass.
(9) The toner for electrophotographic development according to any one of (1) to (4), wherein the colorant is a magenta pigment.
(10) The toner for electrophotographic development according to any one of (1) to (4), wherein the colorant is a cyan pigment.
(11) The toner for electrophotographic development according to any one of (1) to (4), wherein the colorant is a yellow pigment.
(12) The toner for electrophotographic development according to any one of (1) to (4), wherein the colorant is a black pigment.
(13) An electrophotographic image forming method using the electrophotographic toner according to any one of (1) to (12).
(14) An image carrier and a developing device that at least forms an electrostatic latent image formed on the image carrier into a visible image using a developer including toner and a carrier are integrally supported and attached to and detached from the image forming apparatus main body. A process cartridge which can be provided, wherein the toner for electrophotographic development according to any one of (1) to (12) is used as the toner.

  According to the present invention, both excellent low-temperature fixability, high hot offset resistance, and good storage stability are compatible, and even with a low adhesion amount, high coloring power and hiding power are formed, and a high gloss image is formed. It is possible to provide an electrophotographic developing toner, an image forming method, and a process cartridge.

It is a figure which shows the example of the viscoelasticity of the toner which has a peak of loss tangent in 80-160 degreeC. FIG. 4 is a schematic diagram illustrating a state in which toner is directly fixed on paper. FIG. 5 is a schematic diagram showing a state where a color toner is fixed on a white toner layer, but the surface is not smooth and high gloss is not obtained. FIG. 5 is a schematic diagram showing a state where high gloss is obtained because a color toner having a tangent loss (tan δ) peak of 3 or more is fixed on a white toner layer and the surface becomes smooth. It is a figure which shows an example of the electrophotographic developing device used by this invention. It is a figure which shows an example of the electrophotographic developing device used by this invention. It is a figure which shows an example of the image forming apparatus used by this invention. It is a figure which shows the other example of the image forming apparatus used by this invention. It is a figure which shows an example of the process cartridge used by this invention.

  Next, the form for implementing this invention is demonstrated in detail with drawing. The toner of the present invention has a maximum peak at 80 to 160 ° C. in tangential loss represented by loss elastic modulus (G ″) / storage elastic modulus (G ′) = tangent loss (tan δ) in viscoelasticity measurement. The maximum peak value of the tangent loss is 3 or more, and the reason will be described below.

  In order to fix at a low temperature and ensure high glossiness, it is necessary to give the toner a characteristic that the storage elasticity suddenly decreases from a relatively low temperature. If the storage elastic modulus (G ′) of the toner at the time of fixing can be lowered, the melted toner can easily enter the recording paper having a low surface smoothness and the minute unevenness of the chromatic toner, and the relative elasticity is also high in the viscoelasticity. Therefore, the plastic component becomes high, and the shape of the toner particles is difficult to restore after pressure fixing. Therefore, the spreadability is excellent, the smoothness of the toner layer surface is increased, and a high glossiness can be obtained.

On the other hand, from the standpoint of hot offset resistance, it is important that the storage elastic modulus (G ′) is gradually lowered after the viscosity reaches a certain viscosity, and it is important to maintain the viscosity. G ″) should not cause a sudden drop like the storage elastic modulus (G ′).
Thus, if the storage elastic modulus (G ′) rapidly decreases from a certain temperature and the gradient of the decrease does not become gentle in a certain temperature range, the peak of tangential loss as shown in FIG. 1 does not appear.
Only the toner having such characteristics has a peak of tangent loss, and the temperature of the maximum peak is preferably expressed at 80 to 160 ° C.

  When the maximum peak temperature of the tangent loss is less than 80 ° C., the storage elastic modulus (G ′) is lowered in the storage environment, the storage stability as the toner is deteriorated, and the toner is aggregated in the storage environment. Furthermore, the viscoelasticity at a high temperature becomes too low, and the hot offset resistance is impaired. If the temperature exceeds 160 ° C., the purpose of fixing at a low temperature is impaired.

  Further, when the maximum value of the tangent loss is small, the storage elastic modulus (G ′) does not decrease as compared with the loss elastic modulus (G ″), and preferable low-temperature fixability, hot offset resistance, and high gloss can be achieved simultaneously. When high gloss is imparted, it is important that the tangent loss is 3 or more for the following reason.

  In order to increase the glossiness of the toner layer surface, it is necessary to make the outermost surface of the toner layer as smooth as possible. For this purpose, as described above, it is important to reduce the storage elastic modulus (G ′) and increase the spreadability of the toner layer that forms the outermost surface. The compatibility with the surface holding the toner layer is also an important factor.

  In the case where the toner layer 3 is formed on the paper 1, even when the ratio of the storage elastic modulus (G ′) of the toner is relatively high, during pressure fixing (which is generally used for toner fixing), The plasticity of the paper acts as a cushion to absorb the elasticity of the toner, or the molten toner that is excessive in forming a smooth surface penetrates into the cellulose fibers 2 constituting the paper. The surface can be made smooth (see FIG. 2).

  However, for example, when color (Y, M, C, K) is printed over white toner, the color toner layer 5 is formed on the resin surface formed with the white toner. In this case, unlike the case where an image is formed directly on paper, the white toner layer 4 becomes a wall between the paper 1 and the elasticity of the color toner becomes difficult to be absorbed or becomes extra when forming a smooth surface. The molten toner may not easily escape into the cellulose fibers 2 (see FIG. 3).

  In other words, it may be used under conditions that are more severe with respect to gloss than image formation using only color toner. In this case, if the ratio of storage elastic modulus (G ′) is high, pressure fixing is performed. However, due to the “return” due to the elasticity of the color toner itself, minute irregularities and undulations occur on the outermost surface of the toner layer, the smoothness is impaired, and high gloss is difficult to obtain.

  As a result of intensive studies on the phenomenon, the present inventors have conducted extensive research, and even when a color toner layer 5 is further formed on the white toner layer 4, the loss elastic modulus (G ″) and storage of the toner in the fixing temperature range. If the peak of the tangent loss (tan δ), which is the ratio (G ″ / G ′) of the elastic modulus (G ′), is 3 or more, the color toner can maintain the hot offset resistance and has better extensibility than elasticity. It has been found that the outermost surface of the layer 5 can be smoothed, has high permeability, and can impart high gloss (see FIG. 4).

  Further, since the toner of the present invention is excellent in spreadability, the area covering the recording paper is widened at the time of fixing, and a high image density can be obtained even with a low adhesion amount. In particular, white toner used to form a white base on a colored recording medium such as colored paper or black paper exhibits excellent concealment characteristics.

The peak temperature and the maximum peak value of the tangent loss (tan δ) are determined by the viscoelasticity of the resin. However, the peak temperature and the maximum peak value may be changed depending on the load on the resin during the toner manufacturing process, for example, melt kneading conditions. Is possible.
When using crystalline polyester, etc., the peak temperature and maximum peak value of tangent loss (tan δ) should be changed because the viscoelasticity of the toner changes depending on the softening point of the substance used and the amount of the compound added to the toner. Is possible.

  The tangent loss (tan δ) of the toner is measured by measuring viscoelasticity. In the present invention, 0.8 g of a toner is molded at a pressure of 30 MPa using a 20 mm diameter die, and a frequency of 1.0 Hz is used with an ADVANCED RHEOMETRIC EXPANSION SYSTEM manufactured by TA using a 20 mm parallel cone. 0 ° C / min, strain 0.1% (automatic strain control: allowable minimum stress 1.0 g / cm, allowable maximum stress 500 g / cm, maximum applied strain 200%, strain adjustment 200%), GAP is FORCE after sample setting Loss elastic modulus (G ″), storage elastic modulus (G ′), and tangent loss (tan δ) were measured within a range of 0 to 100 gm, and tangent loss peak temperature (° C.) and tangent loss value were obtained. When the storage modulus (G ′) is 10 or less, the value of the tangent loss (tan δ) is excluded.

The toner of the present invention contains a crystalline polyester resin as a thermoplastic resin.
When a crystalline polyester resin is used in combination, fixing at a low temperature becomes possible and the glossiness of an image can be improved even at a low temperature. The content of the crystalline polyester resin is preferably 1 to 25 parts by mass, more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the resin. If the ratio of the crystalline polyester resin is too high, filming is likely to occur on the surface of the image carrier such as a photoconductor, and storage stability may be deteriorated. Furthermore, if the ratio of the crystalline polyester resin is too high, the transparency of the resin is impaired, and the transparency required for the color toner cannot be ensured.

<Release agent>
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably, 1 type may be used individually, and 2 or more types may be used together.
When creating an image such as creating an image on a white toner, the toner layer present on the outermost surface is required to have particularly high hot offset resistance, but contains a release agent in the toner. As a result, the releasability from the fixing member can be increased. The release agents that can be used include liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, polyolefin wax, and partial oxides thereof, or aliphatic hydrocarbons such as fluoride and chloride, animal oils such as beef tallow and fish oil, Palm oil, soybean oil, rapeseed oil, rice bran wax, carnauba wax and other vegetable oils, montan wax and other higher fatty alcohols and higher fatty acids, fatty acid amide, fatty acid bisamide, zinc stearate, calcium stearate, magnesium stearate, aluminum stearate , Metal soaps such as zinc oleate, zinc palmitate, magnesium palmitate, zinc myristate, zinc laurate, zinc behenate, fatty acid esters, polyvinylidene fluoride, etc. Not intended to be.

  The release agents may be used alone or in combination of two or more, but when contained in the toner, they are in the range of 0.1 to 15 parts by weight, preferably 1 to 7 parts by weight with respect to 100 parts by weight of the fixing resin. contains. By containing a release agent in the toner, hot offset resistance and fixing strength at the time of fixing can be obtained, and a high rubbing test strength can be obtained. As a result, when used in a high-speed image forming apparatus, low temperature fixability can be ensured. When the amount added is less than 0.1 parts by mass, offset tends to occur, and when it exceeds 15 parts by mass, carrier spent tends to occur, and the image quality easily deteriorates. When the toner surface layer contains a release agent, it is preferably contained in an amount of 0.001 to 1 part by weight, preferably 0.01 to 0.3 part by weight, based on 100 parts by weight of the fixing resin.

  It is preferable to contain a fatty acid amide in the toner because the crystallization of the crystalline polyester is promoted and the storage stability can be improved in addition to the effect as a release agent. Fatty acid amide may be used alone, but may be used in combination with a release agent other than the fatty acid amide to separate and control the release function and the crystallization promotion function of the crystalline polyester. For example, carnauba wax or paraffin wax that is effective for releasability and a fatty acid amide wax may be used in combination. Examples of fatty acid amide waxes include stearic acid amide, oleic acid amide, erucic acid amide, ethylene-bisstearic acid amide, etc., and N, N′-ethylene-bisstearic acid amide is a particularly effective and preferred example. Is mentioned.

<Colorant>
There is no restriction | limiting in particular as a color of the said coloring agent, According to the objective, it can select suitably, For example, the thing for black, the thing for white, the thing for white, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the black material include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, copper, iron (CI pigment black 11), and titanium oxide. And organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 177, 179, 202, 206, 207, 209, 211; C.I. I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45, copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton, green 7 and green 36, and the like.

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 0-16, 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 151, 154, 180; C.I. I. Bat yellow 1, 3, 20, orange 36 and the like.

  The content of the colorant for black and color in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1% by mass to 15% by mass, and 3% by mass to 10% by mass. Is more preferable. When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor pigment dispersion in the toner occurs, the coloring power decreases, The characteristics may be degraded.

Examples of the white color include metals such as calcium carbonate, silica, zirconia oxide, zinc oxide, and titanium oxide, N, N-bis (4,6-1,3,5-triazin-2-yl ) Organic pigments such as ethylenediamine.
In particular, among white pigments, organic pigments are preferable, and N, N-bis (4,6-1,3,5, -triazin-2-yl) ethylenediamine is more preferable in terms of pigment dispersion. Although the detailed mechanism is unknown, it is considered that organic pigments are easy to disperse in the resin because their specific gravity is lighter than inorganic pigments. In particular, N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine was suitable for dispersion in a polyester-based resin.

  The content of the white colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass to 70% by mass, and more preferably 20% by mass to 50% by mass. . When the content is less than 10% by mass, the hiding power of the toner is reduced, and when it exceeds 70% by mass, the dispersion of the pigment in the toner is deteriorated and the electrical characteristics of the toner are deteriorated. There is.

The toner of the present invention can contain a charge control agent.
Examples of charge control agents include modified products of nigrosine and fatty acid metal salts, onium salts such as phosphonium salts and lake lakes thereof, triphenylmethane dyes and lake lake pigments, metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide Diorganotin oxides such as dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, organometallic complexes, chelate compounds, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, There are aromatic dicarboxylic acid metal complexes and quaternary ammonium salts. Others include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. These can be used alone or in combination of two or more.

  When these charge control agents are internally added to the toner, it is preferable to add 0.1 to 10 parts by mass with respect to the fixing resin, and since they may be colored with the charge control agent, As the transparent color and white toner, select a white or transparent color as much as possible.

  Furthermore, the toner of the present invention can contain an external additive. External additives include, for example, abrasives such as silica, Teflon resin powder, polyvinylidene fluoride powder, cerium oxide powder, silicon carbide powder, strontium titanate powder, or titanium oxide powder, aluminum oxide powder, etc. Fluidity-imparting agents, anti-aggregation agents, resin powders, or conductivity-imparting agents such as zinc oxide powder, antimony oxide powder, tin oxide powder, and reverse polarity white and black fine particles are used as developability improvers. It can also be used. These can be used singly or in combination, and are selected so as to have resistance against development stress such as idling.

When using the two-component developer method, the magnetic fine particles used in the magnetic carrier are one or more of spinel ferrites such as magnetite and gamma iron oxide, and metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.) Magnetoplumbite type ferrites such as spinel ferrite and barium ferrite, and iron or alloy particles having an oxide layer on the surface can be used. The shape may be granular, spherical, or needle-shaped. In particular, when high magnetization is required, it is preferable to use ferromagnetic fine particles such as iron. In view of chemical stability, it is preferable to use magnetoplumbite type ferrite such as spinel ferrite and barium ferrite containing magnetite and gamma iron oxide.
Specifically, MFL-35S, MFL-35HS (manufactured by Powder Tech), DFC-400M, DFC-410M, SM-350NV (manufactured by Dowa Iron Powder Industry Co., Ltd.) and the like are preferable examples.

  A resin carrier having a desired magnetization can be used by selecting the type and content of the ferromagnetic fine particles. At this time, the magnetic property of the carrier is preferably 30 to 150 emu / g as the magnetization intensity at 1,000 oersted. Such a resin carrier is manufactured by spraying a melt-kneaded product of magnetic fine particles and an insulating binder resin with a spray dryer, or reacting and curing a monomer or prepolymer in an aqueous medium in the presence of the magnetic fine particles. A resin carrier in which magnetic fine particles are dispersed in a condensed binder can be produced.

Chargeability can be controlled by fixing positively or negatively charged fine particles or conductive fine particles on the surface of the magnetic carrier, or coating a resin.
Silicone resin, acrylic resin, epoxy resin, fluorine resin, etc. are used as the coating material on the surface, and it can be coated with positively or negatively charged fine particles or conductive fine particles. Silicone resin and acrylic resin Is preferred.

  In the present invention, the weight ratio of the carrier in the developer contained in the developing device is preferably 85 wt% or more and less than 98 wt%. If it is less than 85 wt%, toner scattering from the developing device is likely to occur, causing a defective image. If it is 98 wt% or more, the charge amount of the toner excessively increases or the supply amount of the toner is insufficient, so that the image density is lowered and a defective image is caused.

  In order to prepare the toner in the present invention, for example, a fixing resin, a release agent, a colorant and, if necessary, a charge control agent and a fixing resin in which additives are uniformly dispersed are combined to form a Henschel mixer or a super mixer. After thoroughly mixing with a mixer such as the above, melt and knead using a hot melt kneader such as a heating roll, kneader, extruder, etc., and thoroughly mix the materials, and after cooling and solidification, fine grinding and classification are performed. Get toner. The pulverization method at this time includes a jet mill method in which toner is included in a high-speed air stream, the toner collides with an impact plate, and pulverizes with the energy, an inter-particle collision method in which toner particles collide with each other in the air flow, and further A mechanical pulverization method in which toner is supplied and pulverized between a rotated rotor and a narrow gap can be used.

  In addition, an oil phase in which a toner material is dissolved or dispersed in an organic solvent phase is dispersed in an aqueous medium phase, a resin is reacted, and then the solvent is removed, followed by filtration, washing, and drying, thereby forming a toner base. A solution suspension method for producing particles is also possible. Further, a toner base may be produced by a polyester elongation method.

An example of the electrophotographic developing apparatus in the present invention is shown in FIG.
5, reference numeral 101A denotes a driving roller, 101B denotes a driven roller, 102 denotes a photosensitive belt, 103 denotes a charger, 104 denotes a laser writing system unit, and 105B to 105E store toners of yellow, magenta, cyan, and black, respectively. Development unit 105E for developing white toner, 106 for a paper feed cassette, 107 for an intermediate transfer belt, 107A for a drive shaft roller for driving the intermediate transfer belt, and 107B for a driven shaft roller for supporting the intermediate transfer belt. , 108 is a cleaning device, 109 is a fixing roller, 109A is a pressure roller, 110 is a paper discharge tray, and 113 is a paper transfer roller.
In this color image forming apparatus, a flexible intermediate transfer belt 107 is used for the transfer drum, and the intermediate transfer belt 107 as an intermediate transfer member is stretched between a driving shaft roller 107A and a pair of driven shaft rollers 107B. The belt is circulated and conveyed in the clockwise direction, and the belt surface between the pair of driven shaft rollers 107B is in contact with the photosensitive belt 102 on the outer periphery of the driving roller 101A from the horizontal direction.
During normal color image output, each color toner image formed on the photoreceptor belt 102 is transferred to the intermediate transfer belt 107 each time it is formed, and the color toner images are combined, and this is fed into the paper feed cassette 106. The transfer sheet is transferred onto the transfer sheet by the paper transfer roller 113, and the transferred transfer sheet is transferred between the fixing roller 109 and the pressure roller 109A of the fixing device, and is fixed by the fixing roller 109 and the pressure roller 109A. After fixing, the paper is discharged onto the paper discharge tray 110.

When the developing units 105A to 105E develop toner, the toner concentration of the developer stored in the developing unit is lowered. A decrease in the toner density of the developer is detected by a toner density sensor (not shown). When a decrease in toner density is detected, a toner replenishing device (not shown) connected to each developing unit operates to replenish the toner and increase the toner density. At this time, the replenished toner may be a so-called trickle developing system developer in which a carrier and toner are mixed as long as the developing unit has a developer discharging mechanism.
In FIG. 5, an image is formed by superimposing a toner image on an intermediate transfer belt. However, the electrophotography of the present invention is also applied to a system that directly transfers from a transfer drum to a recording medium without using an intermediate transfer belt. An image forming apparatus can be obtained.

FIG. 6 is a diagram showing an example of a developing device used in the present invention, and modifications as will be described later also belong to the category of the present invention.
In FIG. 6, a developing device (40) disposed opposite to the photosensitive member (20) as a latent image carrier includes a developing sleeve (41) as a developer carrier, a developer containing member (42), It is mainly composed of a doctor blade (43) as a regulating member, a support case (44) and the like.

  A toner hopper (45) serving as a toner accommodating portion for accommodating the toner (21) is joined to the support case (44) having an opening on the photosensitive member (20) side. In the developer accommodating portion (46) for accommodating the developer composed of the toner (21) and the carrier (23) adjacent to the toner hopper (45), the toner (21) and the carrier (23) are agitated. A developer stirring mechanism (47) is provided for imparting friction / release charges to (21).

  Inside the toner hopper (45), a toner agitator (48) and a toner replenishing mechanism (49) are disposed as toner supplying means rotated by a driving means (not shown). The toner agitator (48) and the toner replenishing mechanism (49) send out the toner (21) in the toner hopper (45) toward the developer container (46) while stirring.

  A developing sleeve (41) is disposed in the space between the photoconductor (20) and the toner hopper (45). The developing sleeve (41) driven to rotate in the direction of the arrow by a driving means (not shown) is arranged in a relative position relative to the developing device (40) in order to form a magnetic brush by the carrier (23). A magnet (not shown) is provided as magnetic field generating means.

  A doctor blade (43) is integrally attached to the developer accommodating member (42) on the side facing the side attached to the support case (44). In this example, the doctor blade (43) is disposed in a state where a certain gap is maintained between the tip thereof and the outer peripheral surface of the developing sleeve (41).

  Using such a device without limitation, the image forming method of the present invention is performed as follows. That is, with the above configuration, the toner (21) sent out from the toner hopper (45) by the toner agitator (48) and the toner replenishing mechanism (49) is transported to the developer accommodating portion (46), where the developer agitation is performed. By stirring by the mechanism (47), a desired friction / peeling charge is imparted, and is carried on the developing sleeve (41) as a developer together with the carrier (23) and faces the outer peripheral surface of the photoreceptor (20). The toner image is formed on the photoconductor (20) by being electrostatically coupled to the electrostatic latent image formed on the photoconductor (20) only by being conveyed to the position.

  FIG. 7 is a diagram illustrating an example of an image forming apparatus having the developing device of FIG. Around the drum-shaped photoreceptor (20), a charging member (32), an image exposure system (33), a developing device (40), a transfer device (50), a cleaning device (60), and a static elimination lamp (70) are arranged. In this example, the surface of the charging member (32) is in a non-contact state with a surface of about 0.2 mm from the surface of the photoreceptor (20), and the photoreceptor is driven by the charging member (32). When charging (20), charging unevenness is reduced by charging the photosensitive member (20) with an electric field in which an alternating current component is superimposed on a direct current component by a voltage applying means (not shown) on the charging member (32). It is possible and effective. The image forming method including the developing method is performed by the following operation.

  A series of image forming processes can be described as a negative-positive process. A photoconductor (20) represented by a photoconductor (OPC) having an organic photoconductive layer is neutralized by a static elimination lamp (70) and is uniformly negatively charged by a charging member (32) such as a charging charger or a charging roller. A latent image is formed by laser light emitted from an image exposure system (33) such as a laser optical system (in this example, the absolute value of the exposed portion potential is lower than the absolute value of the non-exposed portion potential). Is called.

  Laser light is emitted from a semiconductor laser and scans the surface of the photoconductor (20) in the direction of the rotation axis of the photoconductor (20) by a polygonal polygonal mirror (polygon) that rotates at high speed. The latent image formed in this way is developed with a developer composed of a mixture of toner and carrier supplied on a developing sleeve (41) which is a developer carrying member in the developing device (40), and the toner image is developed. It is formed. At the time of developing the latent image, a DC voltage of an appropriate magnitude or an AC voltage is applied to the developing sleeve (41) from a voltage application mechanism (not shown) between the exposed portion and the non-exposed portion of the photosensitive member (20). A developing bias with a superimposed voltage is applied.

  On the other hand, a transfer medium (for example, paper) (80) is fed from a paper feed mechanism (not shown), and is synchronized with the leading edge of the image by a pair of upper and lower registration rollers (not shown), so that the photoconductor (20). And the transfer device (50) to transfer the toner image. At this time, it is preferable that a potential having a polarity opposite to the polarity of toner charging is applied to the transfer device (50) as a transfer bias. Thereafter, the transfer medium (80) is separated from the photoreceptor (20) to obtain a transfer image.

The toner remaining on the photoconductor (20) is collected in a toner collection chamber (62) in the cleaning device (60) by a cleaning blade (61) as a cleaning member.
The collected toner may be transported to the developer container (46) and / or the toner hopper (45) by a toner recycling means (not shown) and reused.

  The image forming apparatus may be a device in which a plurality of the developing devices described above are arranged, and the toner images are sequentially transferred onto the transfer medium, then sent to the fixing mechanism, and the toner is fixed by heat or the like. An apparatus may be used in which a plurality of toner images are transferred to a transfer medium and transferred together onto a transfer medium and fixed in the same manner.

  FIG. 8 shows another example of the image forming apparatus used in the present invention. The photosensitive member (20) has at least a photosensitive layer provided on a conductive support, is driven by driving rollers (24a) and (24b), is charged by a charging member (32), and is charged by an image exposure system (33). Transfer using a transfer device (50) having image exposure, development by a developing device (40), exposure before cleaning by an exposure light source (26) before cleaning, cleaning by a brush-like cleaning means (64) and a cleaning blade (61), The charge removal by the charge removal lamp (70) is repeated. In FIG. 8, the photoconductor (20) (of course, the support is translucent in this case) is subjected to pre-cleaning exposure from the support side.

  FIG. 9 shows an example of the process cartridge of the present invention. This process cartridge uses the developer of the present invention, as a photoconductor (20), a proximity brush-like charging means (32), a developing means (40) for storing the developer of the present invention, and a cleaning means. This is a process cartridge that integrally supports a cleaning means having at least a cleaning blade (61) and is detachable from the main body of the image forming apparatus. In the present invention, the above-described components can be integrally combined as a process cartridge, and the process cartridge can be configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.

  Examples of the present invention will be described below, but the present invention is not limited thereby. In the present invention, a polyester resin is used as the binder resin in the examples, but other resins can also be used.

(Binder resin production example: polyester resin)
A monomer selected from an aromatic diol component and ethylene glycol, glycerin, adipic acid, terephthalic acid, isophthalic acid, and itaconic acid according to the composition of Table 1 so that the total amount becomes 4000 g in a 5-liter autoclave having a distillation column. After the esterification reaction under normal pressure and 170-260 ° C. and no catalyst conditions, 400 ppm of antimony trioxide is added to the total carboxylic acid component and the glycol is removed from the system under a vacuum of 3 Torr. Then, polycondensation was performed at 250 ° C. to obtain resins (A1) to (A6). The crosslinking reaction was carried out until the stirring torque reached 10 kg · cm (100 ppm), and the reaction was stopped by releasing the reduced pressure state of the reaction system.

<Measurement of softening point of polyester resin>
Using a flow tester (manufactured by Shimadzu Corporation, CFT-500D), a 1 g sample was heated at a rate of temperature increase of 6 ° C./min, and a load of 1.96 MPa was applied by a plunger, from a nozzle having a diameter of 1 mm and a length of 1 mm. Extrusion, the flow amount of the plunger of the flow tester against the temperature was plotted, and the temperature at which half the sample flowed out was taken as the softening point.

<Measurement of glass transition temperature (Tg) of polyester resin>
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200 ° C., and the temperature was lowered at a rate of 10 ° C./min. The sample cooled to 0 ° C is heated at a heating rate of 10 ° C / min, and the intersection of the baseline extension line below the maximum peak temperature of endotherm and the tangent line indicating the maximum slope from the peak rise to the peak apex Was defined as the glass transition temperature.

<Measurement of acid value of polyester resin>
It measured based on the method of JISK0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

<Measurement of tangent loss peak temperature (° C.) and tangent loss value of polyester resin>
Sample 0.8 g, molded using a 20 mm diameter die at a pressure of 30 MPa, using a 20 mm parallel cone in TA ADVANCED RHEOMETRIC EXPANSION SYSTEM, frequency 1.0 Hz, heating rate 2.0 ° C./min, distortion 0 0.1% (automatic strain control: allowable minimum stress 1.0 g / cm, allowable maximum stress 500 g / cm, maximum applied strain 200%, strain adjustment 200%), GAP is within the range where FORCE is 0 to 100 gm after sample setting. , Loss elastic modulus (G ″), storage elastic modulus (G ′), tangent loss (tan δ) were measured, and tangential loss peak temperature (° C.) and tangent loss value were obtained. The value of tangent loss (tan δ) when ') was 10 or less was excluded.

<Measurement of molecular weight of polyester resin>
The number average molecular weight and the weight average molecular weight of the polyester resin were measured by GPC (gel permeation chromatography) measuring apparatus GPC-150C (manufactured by Waters Co., Ltd.) for the molecular weight distribution of the THF-soluble component.
The measurement is performed by the following method using a column (KF801-807: manufactured by Shodex). The column was stabilized in a heat chamber at 40 ° C., and THF as a solvent was passed through the column at this temperature at a flow rate of 1 ml per minute. After 0.05 g of the sample is sufficiently dissolved in 5 g of THF, it is filtered through a pretreatment filter (for example, a pore diameter of 0.45 μm Chromatodisc (manufactured by Kurabo Industries)), and finally the sample concentration is 0.05 to 0.6% by mass. Inject 50 to 200 μl of a THF sample solution of the prepared resin and measure. In measuring the weight average molecular weight Mw and the number average molecular weight Mn of the THF-dissolved part of the sample, the molecular weight distribution of the sample is determined from the relationship between the logarithmic value of the calibration curve created by several monodisperse polystyrene standard samples and the number of counts. calculate.
As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Or a molecular weight of 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , manufactured by Toyo Soda Kogyo Co., Ltd. It is suitable to use 9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector was used as the detector.

(Production example of crystalline polyester resins B1 and B2)
4000 g of the composition shown in Table 2 and 4 g of hydroquinone were placed in a 5-liter four-necked round bottom flask equipped with a thermometer, stirrer, condenser and nitrogen gas inlet tube, and this flask was set in a mantle heater. 7. Nitrogen gas was introduced from the nitrogen gas inlet tube, the temperature was raised while maintaining the inside of the flask in an inert atmosphere, the temperature was maintained at 160 ° C. for 5 hours, and then reacted at 200 ° C. for 1 hour. Crystalline polyester resins B1 and B2 were obtained by reacting at 3 kPa for 1 hour.

<Measurement of melting point of crystalline polyester resin>
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 150 ° C. at a heating rate of 10 ° C./min, and endothermic. The highest peak temperature was taken as the melting point.

<Measurement of molecular weight of crystalline polyester resin>
The molecular weight of the crystalline polyester was measured by GPC (gel permeation chromatography) in the same manner as the molecular weight of the polyester resin.

(Example of toner production)
-Toner production example 1-
100 parts by mass of a binder resin shown in Table 3, 5 parts by mass of carnauba wax (Carnaluba wax No. 1 manufactured by Celerica NODA), N, N-bis (4,6-1,3,5, -triazine-2- Yl) 50 parts by mass of ethylenediamine was charged into a Henschel mixer “MF20C / I type” (Mitsui Miike Processing Co., Ltd.), mixed with sufficient stirring, kneaded with a twin screw extruder (Toshiba Machine Co., Ltd.), and steel. After cooling on the belt, it was coarsely pulverized to 200 to 300 μm with a hammer mill. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. White toners 1 to 3 and 18 to 20 were produced.

-Toner production example 2-
Binder resin shown in Table 3, and 100 parts by mass of crystalline polyester, carnauba wax (carauba wax No. 1 manufactured by Celerica NODA) 5 parts by mass, N, N-bis (4,6-1,3,5, -Triazin-2-yl) 50 parts by mass of ethylenediamine was charged into a Henschel mixer "MF20C / I type" (manufactured by Mitsui Miike Processing Co., Ltd.), mixed thoroughly, and then mixed into a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.). The mixture was kneaded and cooled on a steel belt, and then coarsely pulverized to 200 to 300 μm with a hammer mill. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. White toner 4 was produced.

-Toner Production Example 3-
Binder resin and crystalline polyester 100 parts by mass shown in Table 3, carnauba wax (carauba wax No. 1 manufactured by Celerica NODA) 5 parts by mass, N, N-bis (4,6-1,3,5,- Triazin-2-yl) 50 parts by mass of ethylenediamine and 3 parts by mass of N, N′-ethylene-bisstearic acid amide were charged into a Henschel mixer “MF20C / I type” (manufactured by Mitsui Miike Processing Co., Ltd.) and mixed thoroughly. After that, the mixture was kneaded with a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), cooled on a steel belt, and coarsely pulverized to 200 to 300 μm with a hammer mill. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. White toners 5-11, 21-23 were produced.

-Toner production example 4-
White toner 12 is produced in the same manner as white toner 5 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 250 parts by mass. did.

-Toner production example 5-
White toner 13 is produced in the same manner as white toner 5 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 13 parts by mass. did.

-Toner Production Example 6
White toner 1 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 50 parts by mass of titanium oxide (Ishihara Sangyo, R50-2) , 18 produced white toners 14 and 24.

-Toner Production Example 7-
White toner 4 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 50 parts by mass of titanium oxide (Ishihara Sangyo, R50-2) A white toner 15 was produced in the same manner as described above.

-Toner Production Example 8-
White toner 5 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 50 parts by mass of titanium oxide (Ishihara Sangyo, R50-2) A white toner 16 was produced in the same manner as described above.

-Toner Production Example 9-
White toner 11 except that 50 parts by mass of N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine is changed to 50 parts by mass of titanium oxide (Ishihara Sangyo, R50-2) , 23, white toners 17 and 25 were produced.

<Measurement of tangent loss peak temperature (° C.) and tangent loss value of toner>
The tangent loss peak temperature (° C.) and tangent loss value of the toner were measured in the same manner as the tangent loss peak temperature (° C.) and tangent loss value of the polyester resin, and are shown in Table 4.

-Example of master batch production-
Add 50 parts of carbon black (manufactured by Cabot Corporation, Regal 400R), 50 parts of polyester resin (manufactured by Sanyo Kasei Kogyo Co., Ltd., RS801), add 30 parts of water, and mix with a Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.). The mixture was kneaded at 160 ° C. for 50 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain Black Masterbatch 1. C. I. A cyan masterbatch was prepared in the same manner except that Pigment Blue 15: 3 was used instead of carbon black.

-Toner Production Example 10-
100 parts by weight of the binder resin shown in Table 5, 4 parts by weight of carnauba wax (Carnaluba wax No. 1 manufactured by Celerica NODA), and 16 parts by weight of black masterbatch were added to a Henschel mixer “MF20C / I type” The mixture was sufficiently stirred and mixed, kneaded with a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), cooled on a steel belt, and coarsely pulverized to 200 to 300 μm with a hammer mill. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. Black toners 1 and 7 were produced.

-Toner Production Example 11-
The binder resin shown in Table 5 and 100 parts by weight of crystalline polyester, 5 parts by weight of carnauba wax (Carnauba wax No. 1 made by Celarica NODA), and 16 parts by weight of black masterbatch were mixed with a Henschel mixer “MF20C / I type” ( Prepared by Mitsui Miike Processing Machine Co., Ltd.), sufficiently stirred and mixed, kneaded by a twin screw extruder (manufactured by Toshiba Machine Co., Ltd.), cooled on a steel belt, and coarsely crushed to 200-300 μm by a hammer mill. did. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. Black toner 2 was produced.

-Toner Production Example 12-
Binder resin shown in Table 5, and 100 parts by weight of crystalline polyester, 5 parts by weight of carnauba wax (Carnauba wax No. 1 manufactured by Celerica NODA), 16 parts by weight of black masterbatch, N, N′-ethylene-bisstearin 3 parts by weight of acid amide is charged into a Henschel mixer “MF20C / I type” (Mitsui Miike Processing Co., Ltd.), mixed with sufficient stirring, kneaded with a twin screw extruder (Toshiba Machine Co., Ltd.), and steel. After cooling on the belt, it was coarsely pulverized to 200 to 300 μm with a hammer mill. Next, after finely pulverizing using a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.), adjusting the pulverization air pressure appropriately so that the weight average particle diameter becomes 5.2 ± 0.3 μm. The weight average particle diameter is 6.0 ± 0.2 μm and the ratio of the weight average particle diameter / number average particle diameter is 1.20 or less with an airflow classifier (manufactured by Nippon Pneumatic Industry Co., Ltd., MDS-I). In this way, classification was performed while appropriately adjusting the louver opening to obtain toner base particles. Next, 1.0 part by mass of additive (HDK-2000, manufactured by Clariant Co., Ltd.) and 1.0 part by mass (H05TD, manufactured by Clariant Co., Ltd.) are mixed with 100 parts by mass of toner base particles with a Henschel mixer. Black toners 3 to 6 and 8 to 10 were produced.

-Toner Production Example 13-
Cyan toners 1 and 7 were produced in the same manner as in Production Example 10 except that 16 parts by mass of the black master batch was changed to 16 parts by mass of the cyan master batch.

-Production of toner 14-
Cyan toner 2 was produced in the same manner as in Production Example 10 except that 16 parts by mass of black masterbatch was changed to 16 parts by mass of cyan masterbatch.

-Toner Production Example 15-
Cyan toner toners 3 to 6 and 8 to 10 were produced in the same manner as in Production Example 12 except that 16 parts by mass of the black master batch was changed to 16 parts by mass of the cyan master batch.

<Measurement of tangent loss peak temperature (° C.) and tangent loss value of toner>
The tangent loss peak temperature (° C.) and tangent loss value of the toner were measured in the same manner as the tangent loss peak temperature (° C.) and tangent loss value of the polyester resin, and are shown in Table 6.

(Example of production of two-component developer)
<Creation of carrier>
Silicone resin (organostraight silicone) 100 parts by mass Toluene 100 parts by mass γ- (2-aminoethyl) aminopropyltrimethoxysilane 5 parts by mass Carbon black 10 parts by mass The above mixture is dispersed with a homomixer for 20 minutes, and a coating layer is formed. A forming solution was prepared. Using this coating layer forming liquid, as a core material, Mn ferrite particles having a weight average particle diameter of 35 μm, and using a fluidized bed type coating apparatus so that the average film thickness is 0.20 μm on the core material surface, The temperature in the fluidized tank was controlled to 70 ° C. and applied and dried. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier A.

[Examples 1 to 17]
The following evaluation was carried out using a two-component developer using the produced white toners 1-17.
<Preparation of two-component developer>
Using the produced white toner and color toner, carrier A, and a tumbler mixer (manufactured by Willy et Bacofen (WAB)), they were uniformly mixed at 48 rpm for 5 minutes and charged to prepare two-component developers. The mixing ratio of the toner and the carrier was mixed according to the toner concentration of the initial developer of the evaluation machine.

<Glossiness 1>
Using a Ricoh digital full color multifunction machine Imagio Neo C600 remodeling machine (with a linear speed of 320 mm / sec), a 4 cm square solid image is formed so that the developer has an adhesion amount of 0.4 mg / cm ^2. After fixing at 0 ° C. and a NIP width of 15 mm, the glossiness 1 of the image was measured. The paper used for the evaluation was POD gloss coated paper 128 g / m ² made by Oji Paper. Gloss was evaluated by using 10 gloss images using a gloss meter VGS-1D manufactured by Nippon Denshoku Industries Co., Ltd.
〔Evaluation criteria〕
◎: 85 or more ○: 80 or more and less than 85

<Coloring power>
(Color toner)
Using a Ricoh digital full-color multifunction machine Imagio Neo C600 remodeling machine (linear speed is 320 mm / sec), a 4 cm square solid image is formed with each developer so that the adhesion amount is 0.3 mg / cm ^2, and the fixing temperature is 200 After fixing at 0 ° C. and an NIP width of 15 mm, the image density was measured at three points using X-RITE, and the average value was used. The paper used for the evaluation was POD gloss coated paper 128 g / m ² made by Oji Paper.
〔Evaluation criteria〕
◎: 1.40 or more ○: 1.35 or more and less than 1.40 △: 1.20 or more and less than 1.35 ×: less than 1.20

(White toner)
Using a Ricoh digital full-color MFP Imagio Neo C600 remodeled machine (linear speed: 160 mm / sec), a 4 cm square solid image was formed so that the adhesion amount was 1.0 mg / cm ² , the fixing temperature was 200 ° C., and the NIP width After fixing at 15 mm, the blackboard was used as the back, the image density was measured at three points using X-RITE, and the average value of the black density was used. At this time, OHP paper was used for evaluation.
(The higher the white hiding power, the lower the background black density.)
〔Evaluation criteria〕
◎: Less than 0.12 ○: 0.12 or more and less than 0.14 △: 0.14 or more and less than 0.16 ×: 0.16 or more

<Cold offset resistance>
Each developer is loaded into an ultrahigh-speed digital laser printer IPSiO SP9500Pro (manufactured by Ricoh Co., Ltd.), and the toner adhesion amount is 0.20 ± 0.00% on a thick transfer paper (manufactured by NBS Ricoh Co., Ltd., copy printing paper <135>). A 1 cm square solid image of 1 mg / cm ² is prepared, and a scotch mending tape 810 (width 24 mm, manufactured by 3M) is attached on the solid image, and a metal roller 1 kg in weight (diameter 50 mm, manufactured by SUS) is attached on the tape. Was reciprocated 10 times while rolling at a speed of 10 mm / s. The tape was peeled off in a fixed direction at a speed of 10 mm / s, the image afterimage rate was determined from the image density before and after tape peeling using the following formula (1), and cold offset resistance was evaluated according to the following evaluation criteria.
Image residual ratio (%) = (Image density after peeling / Image density before peeling) × 100 (1)
〔Evaluation criteria〕
A: Image remaining ratio is 97% or more B: Image remaining ratio is 92% or more and less than 97% Δ: Image remaining ratio is 80% or more and less than 92% (same as conventional toner)
×: Image remaining rate is less than 80%

<Hot offset resistance>
Each developer is loaded into an ultra-high-speed digital laser printer IPSiO SP9500Pro (manufactured by Ricoh Co., Ltd.), and the toner adhesion amount is 0.40 ± 0. A 1 cm square solid image of 1 mg / cm ² is prepared, fixing is performed by changing the fixing roller temperature, the presence or absence of hot offset is visually evaluated, and the upper limit temperature at which hot offset does not occur is set as the upper limit fixing temperature. The hot offset property was evaluated.
〔Evaluation criteria〕
A: The upper limit temperature of fixing is 240 ° C. or higher. O: The upper limit temperature of fixing is 220 ° C. or higher and lower than 240 ° C. Δ: The upper limit temperature of fixing is 180 ° C. or higher and lower than 220 ° C.
×: Fixing upper limit temperature is less than 180 ° C

<Heat resistant storage stability>
The heat-resistant storage stability was measured using a penetration tester (manufactured by Nikka Engineering Co., Ltd.).
Specifically, 10 g of each toner was weighed and placed in a 30 ml glass container (screw vial) in an environment of a temperature of 20 ° C. to 25 ° C. and 40 to 60% RH, and the lid was closed. After tapping the glass container containing the toner 200 times, leaving it in a thermostat set at 50 ° C. for 48 hours, measuring the penetration with a penetration tester, and heat-resistant storage stability according to the following evaluation criteria Evaluated.
The greater the penetration value, the better the heat resistant storage stability.
〔Evaluation criteria〕
◎: Needle penetration is 30 mm or more ○: Needle penetration is 20 mm to 29 mm
Δ: penetration is 15 mm to 19 mm (equivalent to conventional toner)
X: penetration is 14 mm or less

<Glossiness 2>
Using a Ricoh digital full-color multifunction machine, Imagio Neo C600 remodeling machine (linear speed: 160 mm / sec), white toner with an adhesion amount of 0.4 mg / cm ² on a solid image of white toner with an adhesion amount of 0.8 mg / cm ² Alternatively, an image was formed so as to overlap the solid images of color toners and fixed at a fixing temperature of 200 ° C. and an NIP width of 15 mm, and then the glossiness of the image was measured. The paper used for the evaluation was POD gloss coated paper 128 g / m ² made by Oji Paper. Gloss was evaluated by using 10 gloss images using a gloss meter VGS-1D manufactured by Nippon Denshoku Industries Co., Ltd.
〔Evaluation criteria〕
◎: 85 or more ○: 80 or more and less than 85

<Comparative Examples 1-8>
Evaluation was performed using a two-component developer using white toners 18 to 25 as in the examples. It was set as Comparative Examples 1-8.

  Table 7 shows combinations and evaluation results of Examples 1 to 17 and Comparative Examples 1 to 8.

<Examples 18 to 23, 24-29>
In the same manner as in Example 1, evaluation was performed using a two-component developer using black toners 1 to 6 and cyan toners 1 to 6. It was set as Examples 18-23 and Examples 24-29.

<Comparative Examples 9-12, 13-16>
Evaluation was performed using a two-component developer using black toner 7 to 10 and cyan toner 7 to 10 as in the examples. It was set as Comparative Examples 9-12 and Comparative Examples 13-16.

Table 8 shows combinations and evaluation results of Examples 18 to 29 and Comparative Examples 9 to 16.

(Figures 2-4)
1 Paper 2 Cellulose fiber 3 Toner layer 4 White toner layer (lower layer)
5 Color toner layer (upper layer)
6 Toner particles (Figure 5)
101A Drive roller 101B Follower roller 102 Photoreceptor belt 103 Charger 104 Laser writing system units 105A to 105D Development unit 105E containing toner of each color of yellow, magenta, cyan, and black Each development unit 106 containing white toner Cassette 107 Intermediate transfer belt 107A Drive shaft roller 107B for driving the intermediate transfer belt Driven shaft roller 108 for supporting the intermediate transfer belt Cleaning device 109 Fixing roller 109A Pressure roller 110 Paper discharge tray 113 Paper transfer roller (FIG. 6)
20 Photosensitive drum 21 Toner 23 Carrier 41 Developing sleeve 42 Developer accommodating member 43 Developer supply regulating member 44 Support case 45 Toner hopper 46 Developer accommodating portion 47 Developer agitating mechanism 48 Toner agitator 49 Toner replenishing mechanism (FIG. 7)
20 Photosensitive drum 32 Image carrier charging member 33 Image exposure system 40 Developing device 41 Developing sleeve 45 Toner hopper 47 Developer stirring mechanism 50 Transfer mechanism 60 Cleaning mechanism 61 Cleaning blade 62 Toner recovery chamber 70 Static elimination lamp 80 Intermediate transfer medium (FIG. 8)
20 Photosensitive drum 24a Driving roller 24b Driving roller 26 Pre-cleaning exposure light source 32 Image carrier charging member 33 Image exposure system 40 Developing device 50 Transfer mechanism 61 Cleaning blade 64 Brush-like cleaning means 70 Static elimination lamp (FIG. 9)
20 Photoconductor 32 Charging means 40 Developing means 61 Cleaning means

JP 2006-220694 A Japanese Patent Laid-Open No. 1-105962 JP 2000-56514 A

Claims (14)

An electrophotographic developing toner containing at least a binder resin, a colorant and a release agent,
In the viscoelasticity of the toner, tangential loss represented by loss elastic modulus (G ″) / storage elastic modulus (G ′) = tangent loss (tan δ) has a peak at 80 to 160 [° C.],
The toner for electrophotographic development is characterized in that the peak value of tangent loss is 3 or more.   The toner for electrophotographic development according to claim 1, wherein the binder resin contains a crystalline polyester resin.   The toner for electrophotographic development according to claim 1, wherein the toner contains a fatty acid amide inside.   The toner for electrophotographic development according to claim 3, wherein the fatty acid amide is N, N'-ethylene-bisstearic acid amide.   The toner for electrophotographic development according to claim 1, wherein the colorant is a white pigment.   The toner for electrophotographic development according to claim 5, wherein the white pigment is an organic white pigment.   The toner for electrophotographic development according to claim 6, wherein the organic white pigment is N, N-bis (4,6-1,3,5-triazin-2-yl) ethylenediamine.   The toner for electrophotographic development according to any one of claims 5 to 7, wherein the content of the white pigment is 10 to 70% by mass.   The toner for electrophotographic development according to any one of claims 1 to 4, wherein the colorant is a magenta pigment.   The toner for electrophotographic development according to claim 1, wherein the colorant is a cyan pigment.   The toner for electrophotographic development according to claim 1, wherein the colorant is a yellow pigment.   The toner for electrophotographic development according to claim 1, wherein the colorant is a black pigment.   An electrophotographic image forming method using the electrophotographic developing toner according to claim 1. An image bearing member and a developing device that at least forms an electrostatic latent image formed on the image bearing member with a developer including toner and a carrier to be a visible image are integrally supported and detachably mounted on the image forming apparatus main body. A process cartridge, wherein the toner for electrophotographic development according to claim 1 is used as the toner.

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