JP6691688B2 - Carrier for electrostatic latent image developer, two-component developer, replenishment developer, image forming apparatus, and toner accommodating unit - Google Patents

Description

  The present invention relates to a carrier for an electrostatic latent image developer, a two-component developer using the same, a replenishment developer, an image forming apparatus, and a toner accommodating unit.

  In electrophotographic image formation, an electrostatic latent image is formed on an electrostatic latent image carrier such as a photoconductive material, and charged toner is attached to the electrostatic latent image to form a toner image. After that, the toner image is transferred to a recording medium and then fixed, and an output image is formed. Until now, the technology of electrophotographic copying machines and printers has expanded from monochrome to full-color, and in recent years there has been a leap in technological innovation, with white toners and transparent toners with special functions appearing on the market. Is progressing.

  Also in full-color image formation, an oilless system tends to be adopted for the purpose of downsizing the fixing device and simplifying the configuration, as in monochrome image formation. However, in full-color image formation, it is necessary to reduce the viscoelasticity of the toner at the time of melting in order to smooth the surface of the fixed toner image, and thus offset occurs as compared with the case of monochrome image formation without gloss. It is easy and difficult to adopt an oilless system. Further, when a toner containing a release agent is used, the toner adherence is enhanced and the transferability to the recording medium is reduced. Further, there is a problem in that the filming of the toner occurs and the charging property is lowered, so that the durability is lowered.

  In full-color image formation, generally, three colors of color toners of yellow, magenta, and cyan or four color toners in which black color is added are laminated to reproduce all colors. Therefore, in order to obtain a clear full-color image with excellent color reproducibility, it is necessary to smooth the surface of the fixed toner image to reduce light scattering. For these reasons, the image gloss of conventional full-color copying machines is often 10 to 50% of medium to high gloss.

  Generally, as a method for fixing a dry toner image on a recording medium, a contact heat fixing method in which a roller or a belt having a smooth surface is heated and thereby the toner is pressure-bonded is widely used. Such a method has high thermal efficiency and is capable of high-speed fixing, and can impart gloss and transparency to a color toner image, but on the other hand, the surface of the heat fixing member and the molten toner are brought into contact with each other under pressure. Due to the later peeling, a so-called offset phenomenon occurs in which a part of the toner image adheres to the surface of the fixing roller and is transferred onto another image.

  In order to prevent such offset phenomenon, the surface of the fixing roller is formed of silicone rubber or fluororesin, which has excellent releasability, and the toner fixing oil such as silicone oil is applied to the surface of the fixing roller. The method of doing is generally adopted. However, although such a method is extremely effective in preventing toner offset, it requires a device for supplying oil, which causes a problem that the fixing device becomes large.

  Therefore, in monochrome image formation, a toner that has large viscoelasticity when melted and contains a release agent is used in order to prevent internal fracture of the melted toner. There is a tendency to adopt a system in which the coating amount of is minute.

  Also in full-color image formation, an oilless system tends to be adopted for the purpose of downsizing the fixing device and simplifying the configuration, as in monochrome image formation. However, in full-color image formation, it is necessary to reduce the viscoelasticity of the toner at the time of melting in order to smooth the surface of the fixed toner image, and thus offset occurs as compared with the case of monochrome image formation without gloss. It is easy and difficult to adopt an oilless system. Further, when a toner containing a release agent is used, the toner adherence is enhanced and the transferability to the recording medium is reduced. Further, there is a problem in that the filming of the toner occurs and the charging property is lowered, so that the durability is lowered.

The two-component developer used in the electrophotographic system is composed of a toner and a carrier, and the carrier is mixed and agitated with the toner separately supplied in the developing tank to impart a desired charge to the toner and charge it. It is a carrier substance that carries toner bearing an electrostatic latent image on the photoreceptor to form a toner image.
As a carrier, toner filming prevention, formation of uniform surface, prevention of surface oxidation, prevention of moisture sensitivity deterioration, extension of developer life, prevention of adhesion to the surface of photoreceptor, prevention of photoreceptor It is known that a resin containing carbon black is formed on the surface as a coating layer for the purpose of protection from scratches or abrasion, control of charge polarity, adjustment of charge amount, and the like. However, although the carrier can form a good image in the initial stage, there is a problem that the coating layer is scraped off and the image quality is deteriorated as the number of copies increases. Further, there is a problem that color stains occur due to the coating layer being scraped or the carbon black being detached from the coating layer. Titanium oxide, zinc oxide and the like are generally known as substitute materials for carbon black, but their effect of lowering the volume resistivity is insufficient.

  Patent Document 1 discloses a carrier in which a coating layer containing antimony-doped tin oxide (ATO) is formed as needle-shaped conductive powder. Patent Document 2 discloses a carrier in which a coating layer containing conductive particles in which a tin dioxide layer and an indium oxide layer containing tin dioxide are laminated on the surface of base particles is formed. Further, Patent Document 3 discloses first conductive particles having carbon on the surface of tin oxide particles and second conductive particles in which the surface of metal oxide particles and / or metal salt particles is subjected to a conductive treatment. A carrier having a coat layer containing is disclosed.

  Further, in Patent Document 4, a layered double hydroxide containing a Mg element and an Al element having strong positive chargeability and low environmental variability on the surface of the core material is 1.0 to 80 parts by mass with respect to 100 parts by mass of the resin. A carrier having a resin coating layer containing a part thereof is disclosed. Further, Patent Document 5 discloses a carrier containing a resin component having an acrylic monomer as a constituent component and hydrotalcite dispersed in a particle state of 0.1 μm or more and 0.6 μm or less in a coating layer on the surface of magnetic particles. ing.

However, the carrier described in Patent Document 1 has a problem that the ATO has a bluish color tone, and thus, similar to carbon black, color stain occurs.
The carrier described in Patent Document 2 has problems such as cost and permanent usability because the conductive particles contain a rare metal.
The carrier described in Patent Document 3 has a certain effect on the reduction of the charging ability of the carrier when the toner is balanced in a high image area, but when the toner containing many toner external additives is used. However, when continuous paper feeding was performed with a high image area, the charge was also lowered, and the effect was not sufficient.

In the inventions described in Patent Documents 4 and 5, the function of imparting charge to the toner over time can be maintained for a long period of time, and the problem that the charge ability of the carrier is reduced when the toner is balanced in a high image area is achieved. ..
However, at the same time, in a high-speed and high-power machine, the coating layer is abraded over time, and the low-resistance core material without a coating layer is exposed, so that the resistance decreases over time, and an abnormal image occurs. In Patent Document 4 and Patent Document 5, only the method of adjusting the resistance by using a layered double hydroxide containing high resistance Mg element and Al element in the coating layer is used. It was found that the use of a layered double hydroxide alone containing Al element and Al element causes the coating layer to be abraded over time and the resistance over time to decrease.

  INDUSTRIAL APPLICABILITY The present invention is capable of supplying a developer that not only has a property of imparting charge to a toner of a carrier for a long period of time but also achieves a problem of resistance deterioration over time due to abrasion of a coating layer over time, and low temperature fixing For electrostatic latent image developer used in two-component developer used in electrophotographic method and electrostatic recording method that enables continuous paper feeding with low image area ratio and printing density even in high-speed machine using toner The purpose is to provide a career.

  Therefore, the inventors of the present invention, in a carrier for an electrostatic latent image developer comprising a core particle and a coating layer coating the core particle, the coating layer is a layered double hydroxide containing Al and Mg, Charge the carrier toner to a toner for a long period of time by including the surface exposure amount of Al and Mg of the layered double hydroxide and the intensity measured by fluorescent X-rays within a specific range, which contains a metal oxide and a resin. It has been found that the imparting function can be maintained, and the abrasion of the coating layer with time is suppressed, and the decrease in resistance with time can be reduced.

The above problem can be solved by the following [1] of the present invention.
[1] A carrier for an electrostatic latent image developer comprising core material particles and a coating layer coating the core material particles,
The coating layer contains a layered double hydroxide containing Al and Mg, a metal oxide, and a resin,
The surface exposure amount (Atom%) of Al and Mg in the layered double hydroxide satisfies the relationship of (1) below,
A carrier for an electrostatic latent image developer, characterized in that the intensity (kcps) measured by fluorescent X-ray satisfies the following relationship (2).
2.4 ≦ Al ≦ 5.0, 3.9 ≦ Mg ≦ 8.0 (1)
15 ≦ Al ≦ 28, 18 ≦ Mg ≦ 38 (2)

  The carrier of the present invention can provide not only a long-term charge imparting property to the toner of the carrier, but also a developer that can achieve the problem of resistance deterioration over time due to abrasion of the coating layer over time, and It is possible to provide a developer that enables continuous paper feeding with a printing density of a low image area ratio even in a high-speed machine using low-temperature fixing toner.

1 is a schematic diagram showing an example of an image forming apparatus of the present invention. It is a schematic diagram showing an example of a process cartridge of the present invention.

（式中において、Ｒ¹、ｍ、Ｒ²、Ｒ³、Ｘ、及びＹは以下に該当するものを示す。
Ｒ¹：水素原子、またはメチル基
ｍ ：１〜８の整数
Ｒ²：炭素原子数１〜４のアルキル基
Ｒ³：炭素数１〜８のアルキル基、または炭素数１〜４のアルコキシ基
Ｘ ：１０〜９０モル％
Ｙ ：１０〜９０モル％
ただし、Ｘ、Ｙは共重合体における一般式（Ａ）で表される構造単位と一般式（Ｂ）で表される構造単位の組成比を表す。）
［６］ 前記［１］乃至［５］のいずれかに記載の静電潜像現像剤用キャリア及びトナーを有することを特徴とする二成分現像剤。
［７］ 前記トナーが、カラートナー、白色トナー、または透明トナーであることを特徴とする、前記［６］に記載の二成分現像剤。
［８］ 前記［１］乃至［５］のいずれかに記載の静電潜像現像剤用キャリア及びトナーを有することを特徴とする補給用現像剤。
［９］ 静電潜像担持体と、該静電潜像担持体を帯電させる帯電手段と、該静電潜像担持体上に静電潜像を形成する露光手段と、該静電潜像担持体上に形成された静電潜像を、前記［６］または［７］に記載の二成分現像剤を用いて現像してトナー像を形成する現像手段と、該静電潜像担持体上に形成されたトナー像を記録媒体に転写する転写手段と、該記録媒体に転写されたトナー像を定着させる定着手段とを有することを特徴とする画像形成装置。
［１０］ 前記［６］もしくは［７］に記載の二成分現像剤、または前記［８］に記載の補給用現像剤を収容したことを特徴とするトナー収容ユニット。 The present invention relates to the following [1], but the following [2] to [10] are also included in the embodiment of the present invention, and therefore these will also be described.
[1] A carrier for an electrostatic latent image developer comprising core material particles and a coating layer coating the core material particles,
The coating layer contains a layered double hydroxide containing Al and Mg, a metal oxide, and a resin,
The surface exposure amount (Atom%) of Al and Mg in the layered double hydroxide satisfies the relationship of (1) below,
A carrier for an electrostatic latent image developer, characterized in that the intensity (kcps) measured by fluorescent X-ray satisfies the following relationship (2).
2.4 ≦ Al ≦ 5.0, 3.9 ≦ Mg ≦ 8.0 (1)
15 ≦ Al ≦ 28, 18 ≦ Mg ≦ 38 (2)
[2] In the coating layer, the content B (mass basis) of the metal oxide is based on the content A (mass basis) of the layered double hydroxide containing Al and Mg.
[A] ≦ [B]
The carrier for an electrostatic latent image developer according to [1] above, wherein
[3] The carrier for electrostatic latent image developer according to [1] or [2], wherein the metal oxide is a tin oxide compound or an indium oxide compound.
[4] The carrier for electrostatic latent image developer according to any one of [1] to [3], wherein the resin is a thermosetting resin baked at a softening point temperature or higher. ..
[5] The above-mentioned [1], wherein the resin contains a crosslinked product of a copolymer containing a structural unit represented by the following general formula (A) and a structural unit represented by the general formula (B). A carrier for an electrostatic latent image developer according to any one of [4] to [4].

(In the formula, R ¹ , m, R ² , R ³ , X, and Y represent the following.
R ¹ : hydrogen atom or methyl group m: integer of 1 to 8 R ² : alkyl group having 1 to 4 carbon atoms R ³ : alkyl group having 1 to 8 carbon atoms or alkoxy group having 1 to 4 carbon atoms X : 10 to 90 mol%
Y: 10 to 90 mol%
However, X and Y represent the composition ratio of the structural unit represented by the general formula (A) and the structural unit represented by the general formula (B) in the copolymer. )
[6] A two-component developer comprising the carrier for electrostatic latent image developer and the toner according to any one of [1] to [5].
[7] The two-component developer according to the above [6], wherein the toner is a color toner, a white toner, or a transparent toner.
[8] A replenishment developer comprising the carrier for electrostatic latent image developer and the toner according to any one of [1] to [5].
[9] Electrostatic latent image carrier, charging means for charging the electrostatic latent image carrier, exposure means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image Developing means for developing the electrostatic latent image formed on the carrier with the two-component developer described in [6] or [7] to form a toner image, and the electrostatic latent image carrier. An image forming apparatus comprising: a transfer unit that transfers the toner image formed on the recording medium to a recording medium; and a fixing unit that fixes the toner image transferred to the recording medium.
[10] A toner containing unit containing the two-component developer according to [6] or [7] or the replenishment developer according to [8].

The carrier for electrostatic latent image developer of the present invention will be described in detail.
The carrier of the present invention comprises a core material particle and a coating layer that coats the core material particle, and contains a layered double hydroxide containing Al and Mg in the coating layer, a metal oxide, and a resin. Surface exposure amount (Atom%) of 2.4 ≦ Al ≦ 5.0, 3.9 ≦ Mg ≦ 8.0, and intensity measured by fluorescent X-ray (kcps) of 15 ≦ Al ≦ 28, 18 ≦ Mg ≦ 38 Is a carrier for an electrostatic latent image developer.
In the present invention, it is extremely important to add a metal oxide in addition to the layered double hydroxide containing Al and Mg. The layered double hydroxide containing Al and Mg exerts a great effect on charging, but has little effect on the durability of the carrier coat film. However, by adding a certain amount of metal oxide, the strength of the coating layer can be greatly improved, and the ability to retain the layered double hydroxide in the coating layer can also be improved. The addition of substances is very important.

  Further, in order to exhibit the charging performance, the surface exposure amount of the layered double hydroxide containing Al and Mg having a strong positive charging property and low environmental variability needs to be within a certain range. In the region where the amount of surface exposure (atom%) is less than the lower limit (Al <2.4, Mg <3.9), the formulation amount of the layered double hydroxide containing Al and Mg contained in the coating layer is small. That is, the surface exposure amount is small = the area where the carrier can be charged is reduced, that is, the chargeability of the carrier is reduced. In a high-speed and high-output machine, this decrease in charging property becomes more noticeable, which causes toner scattering and scumming. In the region where the surface exposure amount (Atom%) exceeds the upper limit (5.0 <Al, 8.0 <Mg), the carrier coating layer is formed due to an excessive content of the layered double hydroxide containing Al and Mg existing on the surface. The layered double hydroxide is detached as a mass from the core, exposing the low-resistance core material. The exposure of the core material causes a decrease in resistance over time, which causes an abnormal image such as carrier adhesion.

  Similarly, in the case where the measurement intensity (kcps) by fluorescent X-ray measurement is less than the lower limit (Al <15, Mg <18), the amount of the layered double hydroxide containing Al and Mg contained in the carrier coating layer is Not only does the amount of charge decrease overwhelmingly and the initial chargeability decreases, but also the chargeability when the coating layer is aged over time is barely exhibited, which significantly affects the chargeability over time as a carrier. In the region (28 <A, 38 <Mg) where the intensity (kcps) measured by fluorescent X-ray measurement exceeds the upper limit, the amount of the layered double hydroxide containing Al and Mg is large, and the layered complex hydroxide from the carrier coating layer is used. Hydroxide clumps and desorbs, exposing the low-resistance core material. The exposure of the core material causes a decrease in resistance over time, which causes an abnormal image such as carrier adhesion. Therefore, the surface exposure amount (Atom%) of Al and Mg is 2.4 ≦ Al ≦ 5.0, 3.9 ≦ Mg ≦ 8.0, and the intensity (kcps) measured by fluorescent X-ray is 15 ≦ Al ≦ 28. It must be within a certain range of 18 ≦ Mg ≦ 38.

The surface exposure amounts of Al and Mg of the carrier were measured by AXIS / ULYRA (manufactured by Shimadzu / KRATOS). The beam irradiation area is approximately 900 μm × 600 μm, and the range of 25 carriers × 17 is detected. The penetration depth is 0 to 10 nm, and information near the surface of the carrier is detected.
The specific measurement method was performed in a measurement mode: Electrostatic, an excitation source: monochrome (Al), a detection method: a spectrum mode, and a magnet lens: OFF. First, the detection element was specified by the wide area scan, and then the peak was detected by the narrow scan for each detection element. After that, the Atom% of Al and Mg with respect to all the detected elements was calculated using the attached peak analysis software.

The measurement of Al and Mg by fluorescent X-ray was carried out with ZSX-100e (manufactured by Rigaku Corporation). The X-ray irradiation diameter is 30 mmΦ, the penetration depth is 1 nm to several microns, and information up to the core material portion of the carrier is detected.
As a specific measuring method, the carrier is evenly sprinkled on a circular pressure-sensitive adhesive sheet (manufactured by Lintec Co., diameter 45 mmΦ), adhered to the seal, and then the sheet is shaken to remove the excessive carrier. The amount of carrier attached to the seal is set to 0.10 to 0.12 g. After that, it is set in a sample holder, X-ray generator: maximum output 4 kW, X-ray tube: end window type (Rh), primary filter: Zr, analysis method: wavelength dispersion type, working gas: PR gas (CH ₄ 10 %, Ar 90%), output: 50 kV, 30 mA (the output varies depending on the detected element), and a specific element is irradiated with X-rays. The detected spectrum is corrected using a reference sample, and the intensity is calculated.

In the coating layer, the content B (mass basis) of the metal oxide is [A] ≦ [B] with respect to the content A (mass basis) of the layered double hydroxide containing Al and Mg. Is preferred.
It was found that when [B] = 0, the layered double hydroxide containing Al and Mg was used alone, and the resistance was reduced due to abrasion of the coating layer over time. As a countermeasure against this, an attempt was made to suppress the abrasion of the coating layer by containing a metal oxide in the coating layer and further curing the coating layer. As a result, in the region of [A]> [B], the effect of shaving the coating layer was exerted, and the reduction of resistance was suppressed. Further, in the region of [A] ≦ [B], the present invention has led to the invention of a carrier that exerts a remarkable effect on the abrasion of the coating layer and does not reduce the resistance with time.

The layered double hydroxide is a layered compound having an inorganic skeleton (metal hydroxide layer) having anion exchange ability, and has the general formula [M 2 ⁺ _1-x M ³⁺ x (OH) ₂ ] [A ^n- _{x / n} · mH ₂ O] (wherein, M ²⁺ represents a divalent metal ion, M ³⁺ represents a trivalent metal ion, and A ^n- _{x / n} represents an interlayer anion). It layered double hydroxide containing Al and Mg in the present invention, as the M ^2+, Mg ^2+, as the M ^3+, including Al ^3+. For example, hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ .3H ₂ O, Mg _3.5 Zn _0.5 Al ₂ (OH) ₁₂ CO ₃ .3H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ .3) .5H ₂ O, etc. Examples of the interlayer anion include CO ₃ ²⁻ and OH ⁻ .

As the metal compound, tin oxide compounds, indium oxide compounds, titanium oxide, zinc oxide and the like are preferable, and among the metal oxides, it is more preferable to use any one of tin (IV) oxide compounds and indium (III) oxide compounds. preferable. Since the layered double hydroxide containing Al and Mg contained in the carrier coating layer is highly charged, there are few conducting circuits in the carrier coating layer and the counter charge accumulates on the carrier, which may cause abnormal images such as carrier adhesion. Connect with By adding a metal oxide, preferably a tin oxide compound or an indium oxide compound, to the coating layer, a conduction circuit in the coating layer can be secured and counter charge does not occur. Therefore, the high charging ability originally possessed by the layered double hydroxide containing Al and Mg can be more effectively exhibited.
Examples of the tin oxide compound include tin-doped indium oxide (ITO), phosphorus-doped tin oxide (PTO), and oxygen-deficient tungsten-doped tin (WTO).
The amount of the metal compound contained in the coating layer is preferably 50 to 340 parts by mass with respect to 100 parts by mass of the resin component. When the amount is 340 parts by mass or less, the metal compound does not solidify and detach from the coating layer, and the low-resistance core material is not exposed.

As a resin for the coating layer, a thermosetting resin is preferably fired at a temperature equal to or higher than the softening point. As a characteristic of the thermosetting resin, the polymerization reaction is initiated and the bond structure in the resin is fixed by applying a temperature above the softening point of each resin. By applying a temperature equal to or higher than the softening point after coating the core material with the coating layer, the core material is brought into close contact with and fixed to the core material. The stronger the adhesion between the core material and the coating layer, the more the coating layer as a carrier is suppressed from being scraped, and the reduction in resistance over time can be suppressed.
Examples of the thermosetting resin include a copolymer represented by [Structural Formula 1] shown below, a silicone resin, and an acrylic resin.

ここで、式中において、Ｒ¹、ｍ、Ｒ²、Ｒ³、Ｘ、Ｙは以下に該当するものを示す。
Ｒ¹：水素原子、またはメチル基
ｍ ：１〜８の整数、（ＣＨ₂）_ｍは、炭素原子数１〜８のメチレン基、エチレン基、
プロピレン基、ブチレン基等のアルキレン基
Ｒ²：炭素原子数１〜４のメチル基、エチル基、プロピル基、イソプロピル基、及び
ブチル基等のアルキル基
Ｒ³：炭素数１〜８のメチル基、エチル基、プロピル基、イソプロピル基、及びブチル
基等のアルキル基、または炭素数１〜４のメトキシ基、エトキシ基、プロポキシ
基、ブトキシ基等のアルコキシ基
Ｘ ：１０〜９０モル％
Ｙ ：１０〜９０モル％
ただし、Ｘ、Ｙは共重合体における一般式（Ａ）で表される構造単位と一般式（Ｂ）で表される構造単位の組成比を表す。 The resin in the coating layer is obtained by radical copolymerization of a monomer A component which is a structural unit represented by the following general formula (A) and a monomer B component which is a structural unit represented by the following general formula (B). The copolymer having the structural unit represented by the following general formula (A) and the structural unit represented by the general formula (B) (shown in [Structural Formula 1] below) is hydrolyzed to form a silanol group. It is preferable that the carrier is obtained by crosslinking by heat treatment after being formed and condensed by using a catalyst.

Here, in the formula, R ¹ , m, R ² , R ³ , X, and Y represent the following.
R ¹ : a hydrogen atom or a methyl group m: an integer of 1 to 8, (CH ₂ ) _m is a methylene group having 1 to 8 carbon atoms, an ethylene group,
Alkylene groups such as propylene group and butylene group R ² : Alkyl groups such as methyl group having 1 to 4 carbon atoms, ethyl group, propyl group, isopropyl group, and butyl group R ³ : Methyl group having 1 to 8 carbon atoms, Alkyl group such as ethyl group, propyl group, isopropyl group, and butyl group, or alkoxy group having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group, butoxy group X: 10 to 90 mol%
Y: 10 to 90 mol%
However, X and Y represent the composition ratio of the structural unit represented by the general formula (A) and the structural unit represented by the general formula (B) in the copolymer.

In the structural unit represented by the general formula (A) (hereinafter also referred to as the component A), X = 10 to 90 mol%, and more preferably 30 to 70 mol%.
The component A has an atomic group, tris (trialkylsiloxy) silane, in which a large number of alkyl groups are present in the side chain, and the surface energy becomes smaller as the ratio of the component A to the total resin becomes smaller. Adhesion of components and wax components is reduced. When the content of the component A is 10 mol% or more, a sufficient effect is obtained and the adhesion of the toner component is reduced. On the other hand, when the content is 90 mol% or less, the component B is not reduced, crosslinking proceeds, the toughness increases, the adhesion between the core material and the coating layer improves, and the durability of the carrier coating improves.

R ² is an alkyl group having 1 to 4 carbon atoms, and such a monomer A component is exemplified by a tris (trialkylsiloxy) silane compound represented by the following formula.
In the following formulae, Me is a methyl group, Et is an ethyl group, and Pr is a propyl group.
_{CH 2 = CMe-COO-C} 3 H 6 -Si (OSiMe 3) 3
_{CH 2 = CH-COO-C} 3 H 6 -Si (OSiMe 3) 3
_{CH 2 = CMe-COO-C} 4 H 8 -Si (OSiMe 3) 3
_{CH 2 = CMe-COO-C} 3 H 6 -Si (OSiEt 3) 3
_{CH 2 = CH-COO-C} 3 H 6 -Si (OSiEt 3) 3
_{CH 2 = CMe-COO-C} 4 H 8 -Si (OSiEt 3) 3
_{CH 2 = CMe-COO-C} 3 H 6 -Si (OSiPr 3) 3
_{CH 2 = CH-COO-C} 3 H 6 -Si (OSiPr 3) 3
_{CH 2 = CMe-COO-C} 4 H 8 -Si (OSiPr 3) 3
The method for producing the component A is not particularly limited, but a method of reacting tris (trialkylsiloxy) silane with allyl acrylate or allyl methacrylate in the presence of a platinum catalyst, or a method described in JP-A No. 11-217389. It can be obtained by a method of reacting methacryloxyalkyltrialkoxysilane and hexaalkyldisiloxane in the presence of an acid and an acid catalyst.

The structural unit represented by the general formula (B) (hereinafter, also referred to as B component) is a radically polymerizable difunctional or trifunctional silane compound, and Y = 10 to 90 mol%, More preferably, it is 30 to 70 mol%.
When the B component is 10 mol% or more, sufficient toughness is obtained. On the other hand, when it is 90 mol% or less, the coating film does not become too hard, and the film is less likely to be scraped. Also, the environmental characteristics are improved. If a large number of hydrolyzed crosslinking components remain as silanol groups, environmental characteristics (humidity dependency) may be deteriorated.

  Examples of the monomer B component include 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane and 3-methacryloxypropyl. Examples include methyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri (isopropoxy) silane, and 3-acryloxypropyltri (isopropoxy) silane.

（式中において、Ｒ¹、ｍ、Ｒ²、Ｒ³、Ｒ⁴、ｘ、ｙ、及びｚは以下に該当するものを示す。
Ｒ¹：水素原子、またはメチル基
ｍ ：１〜８の整数
Ｒ²：炭素原子数１〜４のアルキル基
Ｒ³：炭素数１〜８のアルキル基、または炭素数１〜４のアルコキシ基
Ｒ⁴：炭素原子数１〜４のアルキル基、またはアミノ基で置換されていても良い炭素
数１〜４のアルキル基
ｘ ：１０〜４０モル％
ｙ ：１０〜４０モル％
ｚ ：３０〜８０モル％
ただし、ｘ、ｙ、ｚは共重合体におけるＡ成分、Ｂ成分、Ｃ成分の組成比を表し、６０モル％＜ｙ＋ｚ＜９０モル％である。） In the copolymer of the present invention, an acrylic compound (monomer), which serves as a structural unit represented by the following general formula (C), may be added as the C component to the A component and the B component.
An example of the copolymer containing such a C component is a copolymer having a structural unit represented by the following [Structural Formula 2].

(In the formula, R ¹ , m, R ² , R ³ , R ⁴ , x, y, and z are as follows.
R ¹ : hydrogen atom or methyl group m: integer of 1 to 8 R ² : alkyl group having 1 to 4 carbon atoms R ³ : alkyl group having 1 to 8 carbon atoms, or alkoxy group having 1 to 4 carbon atoms R ⁴ : an alkyl group having 1 to ⁴ carbon atoms, or an alkyl group having 1 to ⁴ carbon atoms which may be substituted with an amino group x: 10 to 40 mol%
y: 10 to 40 mol%
z: 30 to 80 mol%
However, x, y, and z represent the composition ratio of A component, B component, and C component in the copolymer, and are 60 mol% <y + z <90 mol%. )

  The C component imparts flexibility to the coating film and also improves the adhesiveness between the core material and the coating film. When the content of the C component is 30 mol% or more, sufficient adhesiveness can be obtained, and when the content of the C component is 80 mol% or less, the content of either the A component or the B component does not become 10 mol% or less, so that the carrier coating has a repellent property. It is possible to achieve both water-based, hardness and flexibility (film scraping).

  The acrylic compound (monomer) serving as the C component is preferably an acrylic acid ester or a methacrylic acid ester, and specifically, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, butyl acrylate, 2- (dimethyl) Amino) ethyl methacrylate, 2- (dimethylamino) ethyl acrylate, 3- (dimethylamino) propyl methacrylate, and 3- (dimethylamino) propyl acrylate are exemplified. Of these, alkyl methacrylate is preferable, and methyl methacrylate is particularly preferable. Further, one kind of these compounds may be used alone, or a mixture of two or more kinds may be used.

  Japanese Patent No. 3691115 discloses a technique for enhancing durability by cross-linking the coating. Japanese Patent No. 3691115 discloses a radical copolymer having an organopolysiloxane having a vinyl group at least at a terminal and at least one functional group selected from the group consisting of a hydroxyl group, an amino group, an amide group and an imide group on the surface of a magnetic particle. It is a carrier for developing an electrostatic charge image, which is characterized by coating a thermosetting resin obtained by crosslinking a copolymer with a polymerizable monomer with an isocyanate compound, but has sufficient durability in peeling and scraping of the coating. The current situation is that they have not been obtained.

  Although the reason is not clear enough, in the case of a thermosetting resin obtained by crosslinking the above-mentioned copolymer with an isocyanate-based compound, as can be seen from the structural formula, the isocyanate in the copolymer resin There are few functional groups per unit mass that reacts (crosslinks) with the compound, and a two-dimensional or three-dimensional dense crosslinked structure cannot be formed at the crosslinking point. Therefore, when used for a long time, the coating film is likely to be peeled off or scraped off (the abrasion resistance of the coating film is small), and it is presumed that sufficient durability is not obtained.

  When the film is peeled off or scraped off, the carrier resistance is lowered and the image quality is changed, and carrier adhesion occurs. Further, the peeling / shaving of the coating film lowers the fluidity of the developer, causes a decrease in the amount of scooped up developer, and causes a decrease in image density, stains due to TC increase, and toner scattering.

The resin is a copolymer resin having a large number of bifunctional or trifunctional crosslinkable functional groups (dots) per unit mass (2 to 3 times more per unit mass). Further, it is considered that the coating film is extremely tough and is not easily scraped, and high durability is achieved because it is crosslinked by polycondensation.
Further, since the cross-linking by the siloxane bond of the present invention has a larger binding energy and is more stable against heat stress than the cross-linking by the isocyanate compound, it is presumed that the temporal stability of the coating film is maintained.

  As the coating resin for the carrier, a silicone resin, an acrylic resin, or a combination of these may be used. This is because acrylic resin has excellent adhesiveness and low brittleness, and therefore has very excellent abrasion resistance, but on the other hand, it has a high surface energy, so when used in combination with a toner that easily spends, the toner component spent is Problems such as a decrease in charge amount due to accumulation may occur. In this case, this problem can be solved by using together with a silicone resin, which has an effect that the toner component is less likely to be spent due to the low surface energy and the spent component is less likely to accumulate due to film abrasion. However, since the silicone resin has weak adhesiveness and high brittleness, it also has a weak point that it has poor wear resistance. Therefore, it is important to obtain the properties of these two resins in a well-balanced manner. It becomes possible to obtain a coating film having abrasion resistance. Therefore, the improvement effect is remarkable. This is because the silicone resin has a low surface energy, so that the toner component is less likely to be spent, and the effect that the spent component is less likely to accumulate due to film abrasion is obtained.

  The silicone resin referred to in the present specification refers to all commonly known silicone resins, such as straight silicone consisting only of organosilosan bond, silicone resin modified with alkyd, polyester, epoxy, acrylic, urethane, etc. However, the present invention is not limited to this. Examples of commercially available straight silicone resins include Shin-Etsu Chemical's KR271, KR255, KR152, and Toray Dow Corning Silicone's SR2400, SR2406, SR2410. In this case, it is possible to use the silicone resin alone, but it is also possible to simultaneously use other components that undergo a crosslinking reaction, a charge amount adjusting component, and the like. Furthermore, as the modified silicone resin, Shin-Etsu Chemical's KR206 (alkyd modified), KR5208 (acrylic modified), ES1001N (epoxy modified), KR305 (urethane modified), and Toray Dow Corning Silicone SR2115 (epoxy modified). , SR2110 (alkyd modified) and the like.

  The acrylic resin as used herein refers to all resins having an acrylic component and is not particularly limited. Further, although it is possible to use the acrylic resin alone, it is also possible to simultaneously use at least one or more other components that undergo a crosslinking reaction. Examples of the other component that undergoes the crosslinking reaction here include, but are not limited to, amino resins and acidic catalysts. The amino resin as used herein refers to guanamine, melamine resin and the like, but is not limited to these. Further, as the acidic catalyst as used herein, all those having a catalytic action can be used. For example, those having a reactive group such as a completely alkylated type, a methylol group type, an imino group type, and a methylol / imino group type are included, but are not limited thereto.

Further, the resin layer more preferably contains a crosslinked product of an acrylic resin and an amino resin.
Thereby, fusion of the resin layers can be suppressed while maintaining an appropriate elasticity.
The amino resin is not particularly limited, but melamine resin and benzoguanamine resin are preferable because they can improve the charge imparting ability of the carrier. Further, when it is necessary to control the charge imparting ability of the carrier appropriately, another amino resin may be used in combination with the melamine resin and / or the benzoguanamine resin.
As the acrylic resin that can be crosslinked with the amino resin, those having a hydroxyl group and / or a carboxyl group are preferable, and those having a hydroxyl group are more preferable. This makes it possible to further improve the adhesion to the core material particles and the conductive fine particles, and also to improve the dispersion stability of the conductive fine particles. At this time, the acrylic resin preferably has a hydroxyl value of 10 mgKOH / g or more, more preferably 20 mgKOH / g or more.

  Examples of the condensation polymerization catalyst include titanium-based catalysts, tin-based catalysts, zirconium-based catalysts, and aluminum-based catalysts. In the present invention, among these various catalysts, among titanium-based catalysts that give excellent results, in particular, Titanium diisopropoxybis (ethylacetoacetate) is most preferred as the catalyst. It is considered that this is because the effect of promoting the condensation reaction of the silanol group is large and the catalyst is hard to deactivate.

In the present invention, the coating layer composition preferably contains a silane coupling agent. Thereby, the conductive fine particles can be stably dispersed.
The silane coupling agent is not particularly limited, but r- (2-aminoethyl) aminopropyltrimethoxysilane, r- (2-aminoethyl) aminopropylmethyldimethoxysilane, r-methacryloxypropyltrimethoxysilane, N -Β- (N-vinylbenzylaminoethyl) -r-aminopropyltrimethoxysilane hydrochloride, r-glycidoxypropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, Vinyltriacetoxysilane, r-chloropropyltrimethoxysilane, hexamethyldisilazane, r-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammoniu Chloride, r-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldiethoxysilane, 1, Examples thereof include 3-divinyltetramethyldisilazane, methacryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride and the like, and two or more kinds may be used in combination.

  As a commercial item of a silane coupling agent, AY43-059, SR6020, SZ6023, SH6026, SZ6032, SZ6050, AY43-310M, SZ6030, SH6040, AY43-026, AY43-031, sh6062, Z-6911, sz6300, sz6075 ,. sz6079, sz6083, sz6070, sz6072, Z-6721, AY43-004, Z-6187, AY43-021, AY43-043, AY43-040, AY43-047, Z-6265, AY43-204M, AY43-048, Z-. 6403, AY43-206M, AY43-206E, Z6341, AY43-210MC, AY43-083, AY43-101, AY43-013, AY43-158E, Z-6920. Z-6940 (Toray Silicone Co., Ltd.).

  The addition amount of the silane coupling agent is preferably 0.1 to 10 mass% with respect to the total of the silicone resin and the copolymer. When the addition amount of the silane coupling agent is 0.1% by mass or more, the adhesiveness between the core material particles or the conductive fine particles and the silicone resin is improved, and the coating layer does not fall off during long-term use. When the content is 10 mass% or less, toner filming does not occur during long-term use.

The thickness of the coating layer is preferably 0.2 to 2.0 μm. When the thickness of the coating layer is 2.0 μm or less, it is easy to form the coating layer. Further, if the coating layer is thickened, the amount of the filler contained at the same time is increased, so that the filler is easily detached, but if the thickness is 2.0 μm or less, there is a problem that the filler is detached from the coating layer. Unlikely to occur.
Further, the thickness of the coating layer can be measured by SEM observation of the cross section.
Specifically, it can be measured as follows.
The carrier is mixed with an embedding resin (Devcon Inc., 2 liquid mixture, 30 minutes curing type epoxy resin), left overnight to cure, and mechanically polished to prepare a rough cross-section sample. A cross section polisher (SM-09010 manufactured by JEOL) was used for this, and the cross section was finished under the conditions of an acceleration voltage of 5.0 kV and a beam current of 120 μA. This is photographed with a scanning electron microscope (Merlin manufactured by Carl Zeiss) under conditions of an acceleration voltage of 0.8 kV and a magnification of 30,000 times. Capture the captured image into a TIFF image, and use Media Cybernetics' Image-Pro Plus to select 50 core particles with an average particle size, and the thickness of the coating layer at 10 locations on one carrier. The thickness of the coating layer was calculated from the average.

  The volume average particle diameter of the core material of the carrier used in the present invention is not particularly limited, but from the viewpoint of carrier adhesion and carrier scattering prevention, it is preferable that the volume average particle diameter is 20 μm or more, such as carrier stripes. From the viewpoint of preventing the occurrence of abnormal images and preventing the deterioration of image quality, those having a thickness of 100 μm or less are preferable, and particularly, those having a thickness of 20 to 60 μm are more suitable for the recent improvement in image quality. I can respond. The volume average particle size can be measured using, for example, a Microtrac particle size distribution model HRA9320-X100 (manufactured by Nikkiso Co., Ltd.).

  The core particles used in the carrier of the present invention are not particularly limited, and can be appropriately selected from those known as two-component electrophotographic carriers as long as they are magnetic materials, for example, iron, cobalt. Examples thereof include ferromagnetic metals such as; iron oxides such as magnetite, hematite, and ferrite; various alloys and compounds; resin particles in which these magnetic substances are dispersed in a resin. Among them, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr ferrite and the like are preferable from the viewpoint of environment. Specifically, preferred examples include MFL-35S, MFL-35HS (manufactured by Powdertech), DFC-400M, DFC-410M, SM-350NV (manufactured by DOWA Electronics).

The coating layer is, for example, a layered double hydroxide containing Al and Mg, a metal oxide, the copolymer, a catalyst, and if necessary, a resin other than the copolymer, for a coating layer containing a solvent. It can be formed using the composition.
Specifically, it may be formed by coating the core material particles with the coating layer composition, hydrolyzing the copolymer to generate silanol groups, and condensing to form a crosslinked product. After coating the core particles with the coating layer composition, the copolymer may be hydrolyzed to generate silanol groups and condensed to form a crosslinked product. While coating the core material particles with the coating layer composition, the method of condensing the silanol groups is not particularly limited, but a method of coating the core material particles with the coating layer composition while applying heat, light or the like. Etc. Further, after coating the core material particles with the coating layer composition, the method of condensing the silanol groups is not particularly limited, after coating the core material particles with the coating layer composition, a method of heat treatment and the like. Can be mentioned.
The heat treatment temperature during this heat treatment is preferably equal to or higher than the softening point temperature.
Further, usually, a resin having a large molecular weight has a very high viscosity, and when applied to core material particles having a small particle diameter, particle aggregation, nonuniformity of the coating layer and the like are likely to occur, and it is extremely difficult to produce a coated carrier. difficult.
Therefore, the copolymer according to the present invention preferably has a weight average molecular weight of 5,000 to 100,000, more preferably 10,000 to 70,000, and more preferably 30,000 to 40,000. It is more preferable that there is. When the weight average molecular weight is 5,000 or more, the strength of the coating layer is high, and when it is 100,000 or less, the liquid viscosity of the coating layer composition is low and the carrier productivity is improved.

The two-component developer of the present invention has the carrier and toner of the present invention.
The toner contains a binder resin and may be any of monochrome toner, color toner, white toner and transparent toner. The toner particles may contain a release agent for application in an oilless system in which the toner fixing oil is not applied to the fixing roller. Such a toner generally causes filming, but the carrier of the present invention can suppress filming. Therefore, the developer of the present invention can maintain good quality for a long period of time. You can

The toner can be manufactured using a known method such as a pulverization method or a polymerization method. The electrostatic latent image developer carrier of the present invention has the same effect when used with a toner prepared by a known pulverization method or when used with a toner prepared by a known polymerization method.
For example, when a toner is produced by a pulverization method, first, a melt-kneaded product obtained by kneading a toner material is cooled, then pulverized and classified to prepare mother particles. Next, in order to further improve transferability and durability, an external additive is added to the base particles to prepare a toner.
At this time, the device for kneading the toner material is not particularly limited, but a batch type two rolls; a Banbury mixer; a KTK type twin screw extruder (manufactured by Kobe Steel Ltd.), a TEM type twin screw extruder (Toshiba Machinery) Continuous twin-screw extruder such as a twin-screw extruder (manufactured by KCK), a PCM-type twin-screw extruder (manufactured by Ikegai Tekko KK), a KEX twin-screw extruder (manufactured by Kurimoto Iron Works Co., Ltd.); Examples include continuous single-screw kneaders such as Co-Kneader (manufactured by Buss Co.).

When the cooled melt-kneaded product is pulverized, it is coarsely pulverized by using a hammer mill, a rotoplex or the like, and then finely pulverized by a fine pulverizer using a jet stream, a mechanical fine pulverizer, or the like. be able to. In addition, it is preferable to grind so that the average particle diameter becomes 3 to 15 μm.
Furthermore, when classifying the crushed melt-kneaded product, a wind-powered classifier or the like can be used. In addition, it is preferable to perform classification so that the average particle diameter of the base particles is 5 to 20 μm.
When the external additive is added to the base particles, the external additive is crushed and adhered to the surface of the base particles by mixing and stirring using a mixer.

The binder resin is not particularly limited, but is a homopolymer of styrene such as polystyrene, poly-p-styrene, or polyvinyltoluene, or a substitute thereof; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene. -Vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-methacrylic acid copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer , Styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene Copolymer, styrene-isoprene copolymer Styrene-based copolymers such as styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polyester, polyurethane, epoxy resin, polyvinyl butyral, polyacrylic acid , Rosin, modified rosin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic petroleum resin and the like, and two or more kinds may be used in combination.
The binder resin for pressure fixing is not particularly limited, but polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene; ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, styrene-methacrylic acid copolymer , Ethylene-methacrylic acid ester copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl acetate copolymers, olefin copolymers such as ionomer resins; epoxy resins, polyesters, styrene-butadiene copolymers, polyvinylpyrrolidone, Methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin and the like are mentioned, and two or more kinds may be used in combination.

  The colorant (pigment or dye) is not particularly limited, but includes cadmium yellow, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, Yellow pigments such as permanent yellow NCG and tartrazine lake; molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK and other orange pigments; bengala, cadmium Red, permanent red 4R, resole red, pyrazolone red, watching red calcium salt, lake red D, brilliant carmine B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B and other red pigments; Fast Violet B, Methyl Violet Lake and other purple pigments; Cobalt Blue, Alkali Blue, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Blue pigments such as phthalocyanine blue partially chlorinated, fast sky blue, indanthrene blue BC; green pigments such as chrome green, chromium oxide, pigment green B, malachite green lake; carbon black, oil furnace black, channel black, lamp black , Azine dyes such as acetylene black and aniline black, black pigments such as metal salt azo dyes, metal oxides and composite metal oxides, and white pigments such as titanium oxide. Gerare may be used in combination of two or more thereof, in the case of the transparent toner may not be used.

  The release agent is not particularly limited, but includes polyolefins such as polyethylene and polypropylene, fatty acid metal salts, fatty acid esters, paraffin wax, amide wax, polyhydric alcohol wax, silicone varnish, carnauba wax, and ester wax. Two or more kinds may be used in combination.

  Further, the toner may further contain a charge control agent. The charge control agent is not particularly limited, but includes nigrosine; an azine dye having an alkyl group having 2 to 16 carbon atoms (see Japanese Patent Publication No. 42-1627); C.I. I. Basic Yellow 2 (C.I. 41000), C.I. I. Basic Yellow 3, C.I. I. Basic Red 1 (C.I. 45160), C.I. I. Basic Red 9 (C.I. 42500), C.I. I. Basic Violet 1 (C.I. 42535), C.I. I. Basic Violet 3 (C.I. 42555), C.I. I. Basic Violet 10 (C.I. 45170), C.I. I. Basic Violet 14 (C.I. 42510), C.I. I. Basic Blue 1 (C.I. 42025), C.I. I. Basic Blue 3 (C.I. 51005), C.I. I. Basic Blue 5 (C.I. 42140), C.I. I. Basic Blue 7 (C.I. 42595), C.I. I. Basic Blue 9 (C.I. 52015), C.I. I. Basic Blue 24 (C.I. 52030), C.I. I. Basic Blue 25 (C.I. 52025), C.I. I. Basic Blue 26 (C.I. 44045), C.I. I. Basic Green 1 (C.I. 42040), C.I. I. Basic dyes such as Basic Green 4 (C.I. 42000); lake pigments of these basic dyes; C.I. I. Solvent Black 8 (C.I.26150), quaternary ammonium salts such as benzoylmethylhexadecyl ammonium chloride, decyl trimethyl chloride; dialkyltin compounds such as dibutyl and dioctyl; dialkyltin borate compounds; guanidine derivatives; vinyl having an amino group. -Based polymers, polyamine resins such as condensation polymers having amino groups; described in JP-B-41-20153, JP-B-43-27596, JP-B-44-6397, and JP-B-45-26478. Metal salt of monoazo dye; salicylic acid described in JP-B-55-42752 and JP-B-59-7385; Zn, Al, Co, Cr, Fe, etc. of dialkyl salicylic acid, naphthoic acid and dicarboxylic acid Metal complex of Examples thereof include honed copper phthalocyanine pigments; organic boron salts; fluorine-containing quaternary ammonium salts; calixarene compounds and the like, but two or more kinds may be used in combination. For color toners other than black, white metal salts of salicylic acid derivatives and the like are preferable.

  The external additive is not particularly limited, but inorganic particles such as silica, titanium oxide, alumina, silicon carbide, silicon nitride, and boron nitride; a polyamine having an average particle size of 0.05 to 1 μm obtained by a soap-free emulsion polymerization method. Resin particles such as methyl methacrylate particles and polystyrene particles may be mentioned, and two or more kinds may be used in combination. Among them, metal oxide particles such as silica and titanium oxide whose surface is hydrophobized are preferable. Furthermore, by using both hydrophobized silica and hydrophobized titanium oxide in combination, and by increasing the addition amount of hydrophobized titanium oxide as compared to hydrophobized silica, it is possible to increase humidity A toner having excellent charge stability can be obtained.

  The image forming apparatus of the present invention includes an electrostatic latent image carrier, a charging unit that charges the electrostatic latent image carrier, and an exposing unit that forms an electrostatic latent image on the electrostatic latent image carrier. A developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier with the two-component developer of the present invention to form a toner image; and a developing unit formed on the electrostatic latent image carrier. The toner image transferred to the recording medium and the fixing means for fixing the toner image transferred to the recording medium are provided, and other means appropriately selected as necessary, for example, neutralization. It has a means, a cleaning means, a recycling means, a control means and the like, and uses the two-component developer of the present invention as a developer.

In the present embodiment, the two-component developer containing the carrier and toner described above is used in the trickle developing system as a replenishment developer and a developer in the developing device, so that even after long-term use. By preventing film scraping on the carrier surface and generation of toner spent on the carrier surface, a decrease in the charge amount of the developer in the developer container and a decrease in the electric resistance value of the carrier can be suppressed, and stable development characteristics can be obtained. can get.
The configuration of the image forming apparatus used in the present invention is not particularly limited, and it is possible to use an image forming apparatus having another configuration as long as it has the same function. ..
The developer in the developing device preferably has a toner concentration of 3 to 11% by mass.
The replenishment developer preferably contains 2 to 50 parts by mass of toner with respect to 1 part by mass of carrier.

The toner containing unit in the present invention refers to a unit having a function of containing toner and containing the developer of the present invention. Examples of the toner storage unit include a developer storage container, a developing device, a process cartridge, and the like.
The developer accommodating container means a container accommodating a developer.
The developing device refers to one having a means for accommodating and developing a developer.
The process cartridge refers to a cartridge in which at least an electrostatic latent image carrier and a developing unit are integrated, a developer is stored, and the process cartridge is detachable from the image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposing unit, and a cleaning unit.

  The image forming method of the present invention comprises a step of forming an electrostatic latent image on an electrostatic latent image carrier and a two-component development of the present invention for the electrostatic latent image formed on the electrostatic latent image carrier. Developing with a developer to form a toner image, transferring the toner image formed on the electrostatic latent image carrier to a recording medium, and fixing the toner image transferred to the recording medium And the process.

  FIG. 1 is a schematic diagram showing the configuration of the image forming apparatus of the present invention. In FIG. 1, a tandem type image forming apparatus having four image forming stations forms images of different colors in each station, and finally a color image is obtained. The image formation will be described below.

  The image forming apparatus 1 includes an original document feeder (ADF) 5 for conveying an original document, a scanner unit 4 for reading an original document, and a digital signal output from the scanner unit that is electrically processed by an image processing unit to generate the image. The image forming section 3 forms an image on a recording sheet based on a digital signal output from the processing section. In the scanner unit 4, the image of the document placed on the document table is read by the color CCD via the irradiation lamp, the mirror and the lens, and the data is sent to the image processing unit. In the image processing section, this data is subjected to necessary processing, converted into an image signal, and sent to the image forming section 3.

In the image forming unit 3, four image forming stations 10Y, 10C, 10M, and 10K that use yellow (Y), cyan (C), magenta (M), and black (K) toners are arranged in parallel, and 4 of them are arranged. For each image forming station 10, one intermediate transfer belt 21 and one secondary transfer roller 25 are arranged. The configuration of a yellow image forming station 10Y is shown as an example of the image forming station 10 that constitutes the image forming apparatus 1. In particular, the cyan image forming station 10C, the magenta image forming station 10M, and the black image forming station 10K have the same configuration and operation unless otherwise described.
The image forming station 10 can be used as the process cartridge 10 that can be attached to and detached from the main body of the image forming apparatus 1.
When the image forming operation is started, in the yellow image forming station 10Y, the surface of the photoconductor 11 which is an electrostatic latent image carrier is uniformly charged by the charging device 12 which is a charging unit. The surface of each of the photoconductors 11Y, 11C, 11M and 11K in which an organic photoconductor layer is formed on an electrically grounded metal core is uniformly negatively charged by the charging devices 12Y, 12C, 12M and 12K by corona discharge. After that, the image parts corresponding to the respective colors are irradiated with light by the exposure devices 30Y, 30C, 30M and 30K including the light emitting means composed of the respective laser diodes, and the photoconductors 11Y, 11C, 11M and 11K are electrostatically charged. A latent image is formed.
Then, an electrostatic latent image of the yellow component image of the full-color original is formed on the photoconductor 11 after charging by exposure from the optical writing exposure device 30, and the electrostatic latent image is developed by the yellow developing device 13Y which is a developing unit. Visualized with yellow toner. Further, the same image forming operation is performed in the cyan image forming station, the magenta image forming station, and the black image forming station 10 with a predetermined time difference, and toner images of cyan, magenta, and black colors are formed on the respective photoconductors 11. To be done. In order to superimpose the toner images Y, C, M, and K formed on the photoconductor 11 in each of the image forming stations 10Y, 10C, 10M, and 10K as one full-color image on the intermediate transfer belt 21, this intermediate transfer is performed. The primary transfer roller 23 is arranged on the back surface side of the belt 21 at a position facing the photoconductor 11 of each image forming station 10, and a predetermined transfer bias is applied to the primary transfer roller 23, whereby the toner of each image forming station 10 is transferred. The images are sequentially transferred onto the intermediate transfer belt 21 in an overlapping manner.

The surface potential of the photoconductor 11 in each image forming station 10 after the transfer to the intermediate transfer belt 21 is eliminated by the photo-electrification unit, and the transfer residual toner remaining on the photoconductor 11 is cleaned by the cleaning device 19 which is a cleaning unit. A series of image forming cycles such as removal by the blade and charging by the charging device 12 described above are repeated. After the transfer by the intermediate transfer belt 21, the surface of the photoconductor 11 is neutralized by an optical neutralization unit, and then a cleaning device 19 removes residual substances such as toner. The toner removed by the cleaning device 19 is transported to the waste toner storage tank through the waste toner transport path.
Adhesive substances such as toner and paper dust remaining on the surface of the intermediate transfer belt 21 after the transfer of the full-color toner image onto the recording paper are removed by the cleaning brush roller and the cleaning blade of the intermediate transfer belt cleaning device 22, and the photoreceptor described above is removed. Like the waste toner, the waste toner is conveyed to the waste toner storage unit. Tension rollers 211 (rollers facing the transfer roller 25), 212, and 213 installed in a transfer unit including the intermediate transfer belt 21, the transfer bias power source, the belt drive shaft, and the like give a tension to the transfer belt by a cam mechanism, or When released, the intermediate transfer belt 21 can be changed into a state in which the intermediate transfer belt 21 is in contact with the photoconductor 11 of each image forming station 10 and a state in which the intermediate transfer belt 21 is separated from the photoconductor 11.
As a result, when the machine is operating, the photoconductor 11 of each image forming station 10 is in contact with the photoconductor 11 before the photoconductor 11 rotates, and when the machine is stopped, the photoconductor 11 is separated from the photoconductor 11. After the toner image is transferred to the intermediate transfer belt 21, the surface of the photoconductor is neutralized by the photo-electrification unit, and the cleaning device 19 first counters the photoconductor rotation direction (upstream position in the photoconductor rotation direction in the cleaning unit). The brush roller is contact-rotated in the direction to disturb the residual toner and adhering substances on the photoconductor to weaken the adhesive force with the photoconductor 11, and a blade made of a rubber elastic body is brought into contact with the photoconductor 11 at the downstream position. By doing so, the disturbed toner and adhering substances described above are removed.

Thereafter, the toner image transferred to the intermediate transfer belt 21 is synchronized with the secondary transfer roller 25 to which a predetermined bias is applied to the toner image on the intermediate transfer belt 21 which has become one full-color image. It is transferred onto the recording paper conveyed. The transfer device 20 includes a primary transfer roller 23, a secondary transfer roller 25, an intermediate transfer belt 21, an intermediate transfer belt cleaning device 22, and the like.
As for the recording paper, the recording paper selected by the control of the image forming apparatus 1 is picked up from the plurality of paper feeding cassettes 40 arranged in the paper feeding device 2 by the pickup roller 42 one by one from the paper feeding cassette 40. Be withdrawn. Then, it is conveyed to the image forming unit 3 by the conveying roller 43. Then, the registration roller 44 measures the timing with the toner image on the intermediate transfer belt 21 and sends the toner image to the secondary transfer roller 25.
After that, the recording paper on which the toner image is transferred is conveyed to the fixing device 50 and heated and pressed to fix the toner image on the recording paper, and a full-color image is output.
In the case of performing double-sided printing, before the sheet is sent from the image fixing device to the sheet discharge tray 48, the sheet is sent back to the double-sided transport section 32. After that, it is again sent to the registration roller 44 and the second surface is printed.

In the developing device 13, a developing sleeve provided with a magnetic field generating means inside is arranged at a position facing the photoconductor 11. The charging device 12 brings a charging roller, which is a charging member arranged facing the photoconductor 11, into a contact or non-contact state, and applies a predetermined voltage from a power source to uniformly charge the surface of the photoconductor 11.
Further, the cleaning device 19 has a cleaning blade for the photoconductor 11. Further, a recovery blade for recovering the cleaned toner, a film and the like and a recovery coil for transporting the toner are provided. The cleaning blade is made of a material such as metal, resin and rubber, but rubber such as fluororubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber and urethane rubber is preferably used, and among them, urethane rubber is particularly preferable. In addition, a fluorocarbon resin, a silicone resin, and a lubricant applying device for applying a metal stearate compound such as zinc stearate or aluminum stearate as a lubricant onto the photoconductor 11 may be additionally provided. In FIG. 1, 24 is a conveyor belt and 47 is a discharge roller.

In FIG. 1, the image forming station 10 used in the image forming apparatus of the present invention also functions as a process cartridge.
FIG. 2 is a schematic diagram showing an example of the configuration of the process cartridge of the present invention. As shown in FIG. 2, in the process cartridge 10, a charging device 12, a developing device 13, and a cleaning device 19 are arranged around the photoconductor 11. The process cartridge 10 may include at least the photoconductor 11 and other process devices. A latent image is formed on the photoconductor 11 by the laser light L emitted from the exposure device 30 arranged above. The process cartridge 10 can be attached to and detached from a main body of an image forming apparatus such as a copying machine or a printer.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, "part" represents a mass part.

<Toner manufacturing example>
-Synthesis of Polyester Resin A-
Into a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 65 parts of an ethylene oxide 2 mol adduct of bisphenol A, 86 parts of a bisphenol A propion oxide 3 mol adduct, 274 parts of terephthalic acid and 2 parts of dibutyltin oxide were charged. Then, the mixture was reacted at 230 ° C. for 15 hours under normal pressure. Next, a polyester resin was synthesized by reacting under a reduced pressure of 5 to 10 mmHg for 6 hours. The obtained polyester resin A has a number average molecular weight (Mn) of 2,300, a weight average molecular weight (Mw) of 8,000, a glass transition temperature (Tg) of 58 ° C., an acid value of 25 mgKOH / g, and a hydroxyl value. It was 35 mg KOH / g.

-Synthesis of prepolymer (polymer capable of reacting with active hydrogen group-containing compound)-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 682 parts of bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 2 mol adduct 81 parts, terephthalic acid 283 parts, trimellitic anhydride 22 parts, And 2 parts of dibutyltin oxide were charged and reacted at 230 ° C. for 8 hours under normal pressure. Then, they were reacted for 5 hours under reduced pressure of 10 to 15 mHg to synthesize an intermediate polyester.
The obtained intermediate polyester has a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 9,600, a glass transition temperature (Tg) of 55 ° C., an acid value of 0.5, and a hydroxyl value. It was 49.
Next, 411 parts of the intermediate polyester, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were charged into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introducing tube, and reacted at 100 ° C. for 5 hours to prepare A polymer (a polymer capable of reacting with an active hydrogen group-containing compound) was synthesized.
The free isocyanate content of the obtained prepolymer was 1.60% by mass, and the solid content concentration of the prepolymer (after standing at 150 ° C. for 45 minutes) was 50% by mass.

-Synthesis of ketimine (compound containing active hydrogen group)-
30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stir bar and a thermometer and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound (active hydrogen group-containing compound). The amine value of the obtained ketimine compound (compound containing active hydrogen machine) was 423.

-Preparation of masterbatch-
Henschel mixer (Mitsui Mining Co.), 1,000 parts of water, 540 parts of carbon black Printex35 (manufactured by Degussa) having a DBP oil absorption of 42 mL / 100 g and pH of 9.5, and 1,200 parts of polyester resin A Mixed with. Next, the obtained mixture was kneaded at 150 ° C. for 30 minutes using a two-roll mill, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Co., Ltd.) to prepare a masterbatch.

-Preparation of aqueous medium-
306 parts of ion-exchanged water, 265 parts of a 10 mass% suspension of tricalcium phosphate, and 1.0 part of sodium dodecylbenzenesulfonate were mixed and stirred, and uniformly dissolved to prepare an aqueous medium.

-Measurement of critical micelle concentration-
The critical micelle concentration of the surfactant was measured by the following method. Analysis was performed using a surface tension meter Sigma (manufactured by KSV Instruments) using an analysis program in the Sigma system. 0.01% by mass of the surfactant was added dropwise to the aqueous medium, and the interfacial tension after stirring and standing was measured. From the obtained surface tension curve, the surfactant concentration at which the interfacial tension did not decrease even when the surfactant was dropped was calculated as the critical micelle concentration. When the critical micelle concentration of sodium dodecylbenzenesulfonate with respect to the aqueous medium was measured by a surface tensiometer Sigma, it was 0.05% by mass with respect to the mass of the aqueous medium.

-Preparation of toner material liquid-
70 parts of polyester resin A, 10 parts of prepolymer and 100 parts of ethyl acetate were placed in a beaker and stirred to dissolve. As a mold release agent, 5 parts of paraffin wax (HNP-9 manufactured by Nippon Seiro Co., Ltd., melting point: 75 ° C.), 2 parts of MEK-ST (manufactured by Nissan Chemical Industries, Ltd.), and 10 parts of masterbatch were added, and an ultra viscomill bead mill was added. (Manufactured by IMEX Co., Ltd.), the liquid was fed at a rate of 1 kg / hour, the peripheral speed of the disk was 6 m / sec, and zirconia beads having a particle diameter of 0.5 mm were filled in 80% by volume. 7 parts was added and dissolved to prepare a toner material liquid.

-Preparation of emulsion or dispersion-
150 parts of the aqueous medium phase was placed in a container and stirred with a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) at a rotation speed of 12,000 rpm, and 100 parts of the toner material liquid was added thereto and mixed for 10 minutes. To prepare an emulsified or dispersed liquid (emulsified slurry).
-Removal of organic solvent-
100 parts of the emulsified slurry was charged into a Kolben equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 12 hours while stirring at a stirring peripheral speed of 20 m / min to obtain a dispersion slurry.

-Washing-
After 100 parts of the dispersion slurry was filtered under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtered. The operation of adding 300 parts of ion-exchanged water to the obtained filter cake, mixing with a TK type homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtering was performed twice. 20 parts of a 10 mass% sodium hydroxide aqueous solution was added to the obtained filter cake, and the mixture was mixed with a TK homomixer (rotation speed 12,000 rpm for 30 minutes), and then filtered under reduced pressure. 300 parts of ion-exchanged water was added to the obtained filter cake, mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered. The operation of adding 300 parts of ion-exchanged water to the obtained filter cake, mixing with a TK type homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtering was performed twice. Further, 20 parts of 10 mass% hydrochloric acid was added to the obtained filter cake, mixed with a TK type homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered.

-Adjusting the amount of surfactant-
To the filter cake obtained by the above washing, 300 parts of ion-exchanged water was added, and the electric conductivity of the toner dispersion liquid when mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm) was measured, The surfactant concentration of the toner dispersion liquid was calculated from the calibration curve of the surfactant concentration prepared in advance. From that value, ion-exchanged water was added so that the surfactant concentration would be the target surfactant concentration of 0.05% by mass, to obtain a toner dispersion liquid.

-Surface treatment process-
The toner dispersion liquid adjusted to the predetermined surfactant concentration was heated at a heating temperature T1 = 55 ° C. for 10 hours in a water bath while being mixed at 5,000 rpm by a TK homomixer. Thereafter, the toner dispersion liquid was cooled to 25 ° C. and filtered. Further, 300 parts of ion-exchanged water was added to the obtained filter cake, mixed with a TK type homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered.

-Dry-
The final filter cake obtained was dried at 45 ° C. for 48 hours with a circulating air drier, and sieved with a mesh having a mesh of 75 μm to obtain toner base particles 1.

-External processing-
Further, with respect to 100 parts by weight of the toner base particles 1, 3.0 parts of hydrophobic silica having an average particle diameter of 100 nm, 1.0 part of titanium oxide having an average particle diameter of 20 nm, and fine particles of hydrophobic silica having an average particle diameter of 15 nm. 1.5 parts of the product were mixed with a Henschel mixer to obtain [Toner 1].

<Resin synthesis example 1>
300 g of toluene was put into a flask equipped with a stirrer and heated to 90 ° C. under a nitrogen gas stream. Then _{thereto, CH 2 = CMe-COO-} C 3 H 6 -Si (OSiMe 3) 3 ( wherein, Me is a methyl group.) 3-methacryloxypropyltrimethoxysilane represented by b (trimethylsiloxy) silane 84. 4 g (200 mmol: Silaplane TM-0701T / manufactured by Chisso Corporation), 3-methacryloxypropylmethyldiethoxysilane 39 g (150 mmol), methyl methacrylate 65.0 g (650 mmol), and 2,2'- A mixture of 0.58 g (3 mmol) of azobis-2-methylbutyronitrile was added dropwise over 1 hour. After the completion of the dropping, a solution of 0.06 g (0.3 mmol) of 2,2'-azobis-2-methylbutyronitrile in 15 g of toluene was further added (2,2'-azobis-2-methylbutyronitrile). A total amount of ronitrile (0.64 g = 3.3 mmol) was mixed at 90 to 100 ° C. for 3 hours to perform radical copolymerization to obtain a methacrylic copolymer R1.

<Career production>
(Example 1)
<Resin liquid 1>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts In resin liquid 1, each of the above materials was dispersed by a homomixer for 10 minutes to prepare a coating layer forming liquid. MnMgSr ferrite with a particle size of 35 μm was used as a carrier core material, and the above resin liquid 1 was applied to a surface of the core material by a Spira coater (manufactured by Okada Seiko Co., Ltd.) at 25 g / min in an atmosphere of 80 ° C. It was applied at a rate and then dried for 8 minutes. The layer thickness was adjusted by the amount of liquid. The obtained carrier was left in an electric furnace at 230 ° C. for 1 hour to be baked, and after cooling, crushed using a sieve having openings of 100 μm to obtain carrier 1.
The volume average particle diameter of the core material was measured by using an SRA type of Microtrac particle size analyzer (Nikkiso Co., Ltd.) and setting the range of 0.7 μm or more and 125 μm or less.

(Example 2)
<Resin liquid 2>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 155.4 parts (Sakai Chemical Industry)
Toluene 1300 parts Carrier 2 was prepared in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 2.

(Example 3)
<Resin liquid 3>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 340 parts Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ 3H ₂ O) 300 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts Carrier 3 was produced in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 3.

(Example 4)
<Resin liquid 4>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 340 parts Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ 3H ₂ O) 155.4 parts (Sakai Chemical Industry)
Toluene 1300 parts A carrier 4 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 4 and the drying time after coating with the spill coater was changed to 15 minutes.

(Example 5)
<Resin liquid 5>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope 220 parts of tin (WTO) (average particle size: 60 nm) 220 parts of hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ 3H ₂ O) (Sakai Chemical Industry)
Toluene 1300 parts Carrier 5 was prepared in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 5.

(Example 6)
<Resin liquid 6>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope 200 parts of tin (WTO) (average particle size: 60 nm) 220 parts of hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ 3H ₂ O) (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts Carrier 6 was prepared in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 6.

(Example 7)
<Resin liquid 7>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Tin-doped indium oxide (ITO ) 260 parts (powder specific resistance: 20 [Ω · cm])
・ Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical)
Toluene 1300 parts Carrier 7 was prepared in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 7.

(Example 8)
<Resin liquid 8>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Titanium oxide 260 parts- Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical)
Toluene 1300 parts A carrier 8 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 8.

(Example 9)
<Resin liquid 9>
-Polypropylene resin solution (solid content concentration: 20 mass%) 253 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten-doped tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotal Site (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical)
Toluene 1300 parts The carrier 9 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 9 and firing in an electric furnace after applying the resin solution was changed to unexecuted.

(Example 10)
<Resin liquid 10>
-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten-doped tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotalcite ( Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical Industry)
Toluene 1300 parts The carrier 10 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 10.

(Example 11)
<Resin liquid 11>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope tin (WTO) (average particle diameter: 60 nm) 260 parts hydrotalcite _{(Mg 3.5 Zn 0.5 Al 2 (} OH) 12 CO 3 · 3H 2 O) 220 parts (Sakai chemical)
Toluene 1300 parts Carrier 11 was produced in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 11.

(Example 12)
<Resin liquid 12>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotalcite (Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ 3.5H ₂ O) 230 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts A carrier 12 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 12.

(Comparative Example 1)
<Resin liquid 13>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 260 parts-Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 120 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts Carrier 13 was prepared in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 13.

(Comparative example 2)
<Resin liquid 14>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (average particle size: 60 nm) 420 parts ・ Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ .3H ₂ O) 400 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts The carrier 14 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 14.

(Comparative example 3)
<Resin liquid 15>
-Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts-Silicone resin solution (solid content 40 mass%) 230 parts-Aminosilane (solid content concentration: 100 mass%) 4 parts-Oxygen-deficient tungsten dope Tin (WTO) (Average particle size: 60 nm) 340 parts-Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 120 parts (Sakai Chemical Industry Co., Ltd.)
Toluene 1300 parts A carrier 15 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 15.

(Comparative example 4)
<Resin liquid 16>
Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts Silicone resin solution (solid content 40 mass%) 230 parts Aminosilane (solid content concentration: 100 mass%) 4 parts Resin fine particles 260 parts Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical)
Toluene 1300 parts Carrier 16 was produced in the same manner as in Example 1 except that resin liquid 1 was changed to resin liquid 16.

(Comparative example 5)
<Resin liquid 17>
Methacrylic copolymer R1 (solid content concentration: 20 mass%) 23 parts Silicone resin solution (solid content 40 mass%) 230 parts Aminosilane (solid content concentration: 100 mass%) 4 parts Hydrotalcite (Mg ₄ Al ₂ (OH) ₁₂ CO ₃ / 3H ₂ O) 220 parts (Sakai Chemical Industry)
Toluene 1300 parts A carrier 17 was produced in the same manner as in Example 1 except that the resin liquid 1 was changed to the resin liquid 17.

Table 1 shows each carrier.

<Preparation of developer>
[Carrier 1] to [Carrier 17] (93 parts by mass) obtained in Examples and Comparative Examples were mixed with Toner 1 (7 parts by mass), and the mixture was stirred for 3 minutes using a turbuler mixer and evaluated. [Developer 1] to [Developer 17] were prepared.

The following evaluations were performed using the obtained [Developer 1] to [Developer 17].
As an evaluation of the charge imparting property to the initial toner, the edge carrier adhesion of the following developer characteristic evaluation 1 was evaluated, and the solid carrier adhesion evaluation of the following developer characteristic evaluation 2 was performed as the evaluation of resistance deterioration with time. As the evaluation of the charge imparting property to the toner, the toner scattering and the background fog in the following developer characteristic evaluation 3 were evaluated. The digital full-color multifunction machine (Pro C9100, manufactured by Ricoh Co., Ltd.) used for evaluation is a high-speed machine, and even when the high-speed machine uses low-temperature fixing toner according to the following developer characteristic evaluations 2 and 3, printing with a low image area ratio is performed. The continuous paper passing at the density was evaluated.

<Developer characteristic evaluation 1>
The obtained developer was set in a commercially available digital full-color composite machine (Pro C9100, manufactured by Ricoh Co., Ltd.), and image evaluation was performed. Specifically, the above machine is put in an environment evaluation room (low temperature and low humidity environment of 10 ° C. and 15%) and left for one day, and thereafter, using the developers 1 to 17 and toner 1 of Examples and Comparative Examples, an initial stage is performed. The edge carrier adhesion was evaluated.

(Adhesion of edge carrier)
Under the developing conditions (charging potential (Vd): -630V, developing bias: DC-500V), 170 μm × 170 μm is set as 1 square, and an image in which solid portions and blank sheets are alternately arranged in the vertical and horizontal directions is output in A3 size, and 1 square is output. The number of white spots in the image due to carrier adhesion at the boundary of one square was counted. ◎ is a state where the number of carrier attachments is 0, ○ is a state where the number of carrier attachments is 1 to 3, Δ is a state where the number of carrier attachments is 4 to 10, and × is a number of carrier attachments This is the above state. ⊚, ○, and Δ were passed, and x was rejected.

<Developer characteristic evaluation 2>
The obtained developer was set in a commercially available digital full-color composite machine (Pro C9100, manufactured by Ricoh Co., Ltd.), and image evaluation was performed. Specifically, the above machine is used in a laboratory environment (25 ° C. 60% environment), using the developers 1 to 17 and toner 1 of the examples and comparative examples, and an image area ratio of 2.5% to obtain 500,000 sheets. And the adhesion of the solid carrier after running 2 million sheets was evaluated.

(Solid carrier adhesion)
After running 500,000 and 2,000,000 sheets, a solid image is formed by a method such as turning off the power during image formation under predetermined developing conditions (charging potential (Vd): -630V, developing bias: DC-500V). Was interrupted, and the number of adhered carriers on the photoreceptor after transfer was counted and evaluated. The area to be evaluated was a 10 mm × 100 mm area on the photoconductor. ⊚ is a state where the number of carrier attachments is 0, ◯ is a state where the number of carrier attachments is 1 to 2, Δ is a state where the number of carrier attachments is 3 to 9, and × is a number of carrier attachments This is the above state. ⊚, ○, and Δ were passed, and x was rejected.

<Developer characteristic evaluation 3>
The obtained developer was set in a commercially available digital full-color composite machine (Pro C9100, manufactured by Ricoh Co., Ltd.), and image evaluation was performed. Specifically, the above machine is put in an environment evaluation room (high temperature and high humidity environment of 27 ° C. and 80%) and left for one day, and thereafter, using the developers 1 to 17 and toner 1 of Examples and Comparative Examples, The background fog and toner scattering were evaluated after running 2 million sheets at an image area ratio of 80%.

(Toner scattering)
After running 2 million sheets, the amount of toner accumulated under the developer carrying member was sucked and collected, and the toner mass was measured. The evaluation criteria are shown below.
0 mg or more and less than 50 mg: ◎ (very good)
50 mg or more and less than 100 mg: ○ (good)
100 mg or more and less than 250 mg: △ (usable)
250 mg or more: × (bad)

(Surface cover)
After running 2 million sheets, the blank image is stopped during development, the toner on the photoconductor after development is tape-transferred, and the difference (ΔID) from the image density of the untransferred tape is adjusted to 938 spectrodensitometer (X-Rite). (Manufactured by the company). The evaluation criteria are shown below.
0 or more and less than 0.005: ◎ (very good)
0.005 or more and less than 0.01: ○ (good)
0.01 or more and less than 0.02: △ (usable)
0.02 or more: × (bad)

Table 2 shows the carriers used in each Example and Comparative Example and the evaluation results.

1 image forming apparatus 2 paper feeding apparatus 3 image forming section 4 scanner section 5 automatic document feeder (ADF)
10 Image forming station (process cartridge)
11 Photoreceptor 12 Charging Device 13 Developing Device 19 Cleaning Device 20 Transfer Device 21 Intermediate Transfer Belt 22 Intermediate Transfer Belt Cleaning Device 23 Primary Transfer Roller 24 Conveyor Belt 25 Secondary Transfer Roller 30 Exposure Device 32 Double-sided Conveying Unit 40 Paper Feed Cassette 42 Pickup Roller 43 Conveying roller 44 Registration roller 47 Discharging roller 48 Discharging tray 50 Fixing device

Japanese Patent Laid-Open No. 11-202560 JP 2006-39357 A JP, 2010-17519, A JP, 2011-69853, A JP, 2013-127587, A

Claims (9)

In a carrier for an electrostatic latent image developer, comprising a core material particle and a coating layer coating the core material particle,
The coating layer contains a layered double hydroxide containing Al and Mg, a metal oxide, and a resin,
The surface exposure amount (Atom%) of Al and Mg in the layered double hydroxide satisfies the relationship of (1) below,
The measurement intensity (kcps) by fluorescent X-ray satisfies the relationship of (2) below,
In the coating layer, the content B (mass basis) of the metal oxide is [A] ≦ [B] with respect to the content A (mass basis) of the layered double hydroxide containing Al and Mg. A carrier for an electrostatic latent image developer, which satisfies the relationship.
2.4 ≦ Al ≦ 5.0, 3.9 ≦ Mg ≦ 8.0 (1)
15 ≦ Al ≦ 28, 18 ≦ Mg ≦ 38 (2)   The carrier for an electrostatic latent image developer according to claim 1, wherein the metal oxide is a tin oxide compound or an indium oxide compound.   3. The carrier for electrostatic latent image developer according to claim 1, wherein the resin is a thermosetting resin baked at a softening point temperature or higher. 4. The resin according to claim 1, wherein the resin contains a crosslinked product of a copolymer containing a structural unit represented by the following general formula (A) and a structural unit represented by the general formula (B). A carrier for an electrostatic latent image developer as described in 1.

(In the formula, R ¹ , m, R ² , R ³ , X, and Y represent the following.
R ¹ : hydrogen atom or methyl group m: integer of 1 to 8 R ² : alkyl group having 1 to 4 carbon atoms R ³ : alkyl group having 1 to 8 carbon atoms or alkoxy group having 1 to 4 carbon atoms X : 10 to 90 mol%
Y: 10 to 90 mol%
However, X and Y represent the composition ratio of the structural unit represented by the general formula (A) and the structural unit represented by the general formula (B) in the copolymer. )   A two-component developer comprising the carrier for an electrostatic latent image developer according to any one of claims 1 to 4 and a toner.   The two-component developer according to claim 5, wherein the toner is a color toner, a white toner, or a transparent toner.   A replenishment developer comprising the carrier for electrostatic latent image developer according to any one of claims 1 to 4 and a toner.   Electrostatic latent image carrier, charging means for charging the electrostatic latent image carrier, exposing means for forming an electrostatic latent image on the electrostatic latent image carrier, and electrostatic latent image carrier Developing means for developing the electrostatic latent image formed on the electrostatic latent image by using the two-component developer according to claim 5 or 6, and a toner formed on the electrostatic latent image carrier. An image forming apparatus comprising: a transfer unit that transfers an image onto a recording medium; and a fixing unit that fixes the toner image transferred onto the recording medium. A toner containing unit containing the two-component developer according to claim 5 or 6, or the replenishment developer according to claim 7 .

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