JPH05249745A - Electrostatic charge image developer - Google Patents

Abstract

PURPOSE:To stably obtain a high-quality picture by incorporating a polyester resin as the binder resin to form a toner, specified carnauba wax as a releasing agent and a specified compd. as an antistatic agent. CONSTITUTION:This toner consists essentially of a carrier coated with a silicone resin, a binder resin, a releasing agent and an antistatic agent. The toner contains a polyester resin as the binder resin, a removed free fatty acid-type carnauba wax and montan ester wax having <=5 acid value and/or an oxidized rice wax having 10-30 acid value as the antistatic agent. One or more kinds of compds. shown by the following A, B and C are incorporated as the release agent. Namely, A is a compd. shown by formula I, B is a quaternary ammonium salt copolymer compd. having structural units shown by formulas II and III with the ratio controlled to 65:35 to 97:3, and C has structures shown by formulas II and IV having the same ratio. In the formulas, R1 and R2 are hydrogen atom or methyl, R3 is alkylene groups, and R3, R4 and R5 are alkyls.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry developer for developing an electrostatic charge image (electrical or magnetic latent image) formed in electrophotography, electrostatic printing or the like, and more specifically, In the heat roll fixing method, fixing is sufficiently performed at a lower temperature,
Further, the present invention relates to a developer that does not adversely affect the developer properties such as charging properties even when used for a long time in the developing device.

[0002]

2. Description of the Related Art An electrostatic charge image formed by an electrophotographic method, an electrostatic printing method, an electrostatic recording method, etc., is generally dried by a dry toner containing a binder resin and a colorant as a main component in the dry method. , Is transferred and fixed on copy paper. Although there are various fixing methods for toner images, the heat roller fixing method is widely adopted because of its high thermal efficiency and high-speed fixing. When performing high-speed fixing by such a heat fixing method, the toner is required to have good low-temperature fixing property (or low fixing lower limit temperature), and therefore, a binder resin having a low softening point is required. used. However, when a low softening point resin is contained in the toner, a part of the toner image adheres to the surface of the heat roller at the time of fixing, and this is transferred onto copy paper to cause scumming, a so-called offset phenomenon or copy paper. Is attached to the surface of the heat roller and is wound around, which is a so-called wrapping phenomenon (especially when the temperature of the heat roller is low).

Therefore, as means for preventing these phenomena, Japanese Patent Application Laid-Open Nos. 51-143333 and 57-14875.
No. 2, No. 58-97056, No. 60-247250, etc., it is proposed to add solid silicone varnish, higher fatty acid, higher alcohol, various waxes and the like as a release agent. However, under the present circumstances, a release agent which exhibits sufficient offset resistance and wrapping resistance while maintaining good low-temperature fixability has not yet been found.

Specifically, conventional polyolefin waxes such as low molecular weight polyethylene and low molecular weight polypropylene have good offset resistance, but do not have sufficient low-temperature fixability, and carnauba wax, candelilla wax and the like. Although the vegetable wax has good offset resistance and low-temperature fixability, it does not have sufficient wrapping resistance, and solid silicone varnish, solid silicone oil, amide wax, higher fatty acid, and higher alcohol have good low-temperature fixability. However, the offset resistance and the wrapping resistance are not sufficient. Moreover, since the conventional release agent has poor dispersibility in the binder resin, the release agent is often released from the toner and adheres to the photoconductor or the developing sleeve during development, so-called filming. Carrier pollution due to
It was difficult to form a high-quality image stably over a long period of time.

On the other hand, it is known to use a polyester resin as a binder resin in order to maintain the low temperature fixability. However, the polyester resin has a strong negative chargeability of the resin itself, and it is difficult to use the resin for a positive charge toner. When the polyester resin is used for a negative charge toner, the polyester resin has a negative chargeability. Therefore, it is difficult to make the toner have a desired charge amount.

As a method of improving this, there is a method of adding a charge-imparting agent. Examples of compounds that have been put into practical use as a positive charge-imparting agent include nigrosine dyes described in Japanese Patent Publication No. 41-2427 and U.S. Pat. No. 3,56.
Examples thereof include quaternary ammonium salts described in JP-A No. 5,654, JP-A No. 60-169857 and the like.
In particular, the nigrosine dye has been widely used since it has a high charge imparting property and is inexpensive. In addition, examples of practically used negative charge imparting agents include metal complex salts of monoazo dyes and metal salts of fatty acids described in JP-A-59-228259. By using these various charge-imparting agents, the triboelectric charge amount can be sufficiently increased. However, the problem that the charge amount of the developer largely changes depending on the use environment is still unsolved. This is particularly remarkable in the case of toner containing carbon black. For this reason, when used in high temperature and high humidity, the charge amount of the developer decreases, background stains, deterioration of resolution, toner scattering, and the like, and in low temperature and low humidity, the charge amount of the developer increases, and Decrease in concentration,
It also has a drawback that a stable image cannot be obtained due to an edge effect or the like.

[0007]

That is, at the time of fixing, while exhibiting good low-temperature fixability, sufficient offset resistance and wrapping resistance are exhibited, and filming and carrier contamination do not occur at the time of development. At present, a toner or a developer capable of stably obtaining a high-quality image for a long period of time has not yet been found.

Accordingly, an object of the present invention is to provide a developer for developing an electrostatic charge image which has sufficient offset resistance at the time of fixing, has a low fixing lower limit temperature, and does not wrap around a fixing roll. .. Further, another object of the present invention is that there is no background stain or toner scattering, it is not affected by changes in temperature and humidity, an image with high fidelity equivalent to the initial image is obtained even during continuous use, and high-speed fixing is possible. Another object of the present invention is to provide a developer suitable for electrostatic image development.

[0009]

As a result of intensive studies, the present inventors have used a polyester resin as a binder resin, contain a specific release agent, and contain a specific charge control agent. It has been found that the above object can be achieved by the toner having the constitution, and the present invention has been completed.

That is, according to the present invention, in a developer comprising a carrier coated with a silicone resin and a toner mainly containing a binder resin, a release agent and a charge control agent, at least the binder of the toner is bound. A polyester resin as a resin, a free fatty acid type carnauba wax having an acid value of 5 or less, a montan ester wax and / or an oxidation rice wax having an acid value of 10 to 30 as a release agent, and a charge control agent. The present invention provides a developer for developing an electrostatic charge image, which comprises at least one of the compounds represented by the following (1) to (3). (1) CIPigment Red 81 represented by the following structural formula [I]
Compounds classified into.

[Chemical 1] (2) It has structural units represented by the following structural formulas [II] and [III], and the ratio of [II] and [III] is 65: 35-9.
7: 3 quaternary ammonium salt copolymer compound.

[Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ]

[Chemical 3] [In the above formula, R ^{2 to} R ⁶ represent the following, respectively. R ² : hydrogen atom or methyl group. R ³ : an alkylene group. ^{R 4, R 5, R 6} : an alkyl group. (3) It has structural units represented by the following structural formulas [II] and [IV], and the ratio of [II] and [IV] is 65: 35-9.
Copolymer compound of 7: 3.

[Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ]

[Chemical 4]

In the developer of the present invention, a polyester resin is used as the binder resin of the toner, and as the release agent, a free fatty acid type carnauba wax having an acid value of 5 or less, a montan ester wax, and an oxidized rice of 10 to 30 oxidation are used. Since at least one wax is used and at least one of the compounds represented by the above (1) to (3) is used as the charge control agent, it has sufficient offset resistance and wrapping resistance during fixing. In addition, since the lower limit fixing temperature is sufficiently low and the dispersibility of the release agent in the binder resin is good, there is little toner filming or carrier contamination during development, and a stable charge amount is obtained for the toner. The image quality is not affected by changes in temperature and humidity, and quality abnormalities such as toner fog on the background of the image are prevented, and it is stable over a long period of time. It becomes capable of forming an image of quality.

The present invention will be described in more detail below. The use of a carrier coated with a silicone resin is desired in a dry two-component developer because the surface energy is low and the toner fusion to the surface can be extremely reduced. However, according to the research conducted by the present inventors, the silicone resin-coated carrier has a charge control capable of imparting appropriate positive or negative chargeability to a toner using a polyester resin binder like the toner used in the present invention. The agents have been found to be of very limited scope. Therefore, in the toner used in the present invention,
As the charge control agent, a red pigment compound represented by the structural formula [I], a quaternary ammonium salt copolymer compound having structural units represented by the structural formulas [II] and [III], and structural formulas [II] and [II] At least one kind of sulfonic acid group-containing copolymer compound having a structural unit represented by IV] is used.

(Red pigment) represented by the following structural formula [I],
According to the compound classified into CIPigment Red 81, it is possible to give the toner a sufficient amount of positive charge.

[Chemical 1]

(Quaternary ammonium salt copolymer) having a structural unit represented by the following structural formulas [II] and [III]:
Even a quaternary ammonium salt copolymer compound having a ratio of I] to [III] of 65:35 to 97: 3 can impart a sufficient positive charge amount to the toner.

[Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ]

[Chemical 3] [In the above formula, R ^{2 to} R ⁶ represent the following, respectively. R ² : hydrogen atom or methyl group. R ³ : an alkylene group. ^{R 4, R 5, R 6} : an alkyl group. ]

The above quaternary ammonium salt copolymer is prepared by first charging styrene, dimethylaminomethacrylate and azobisdimethylvaleronitrile in a mixed solvent under a nitrogen stream, polymerizing them, and further adding methyl paratoluenesulfonate. Salt. Then, the solvent is distilled off, and the product is obtained by pulverizing with a jet mill.

(Sulfonic acid group-containing copolymer) having a structural unit represented by the following structural formulas [II] and [IV], [II]
With the copolymer compound having a ratio of [IV] to 65:35 to 97: 3, a sufficient negative charge amount can be imparted to the toner.

[Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ]

[Chemical 4]

The above sulfonic acid group-containing copolymer is first solution-polymerized by charging styrene, 2-acrylamido-2-methylpropanesulfonic acid and lauroyl peroxide in a mixed solvent under a nitrogen stream and stirring. Then, after distilling off the solvent, the content is taken out and pulverized by a jet mill to obtain it.

The amount of these charge control agents added is 0.3 to 6% by weight, preferably 0.5 to 5% by weight, based on the total toner. If it is less than this range, it is not possible to impart a sufficient charge amount to the toner. On the contrary, if it is more than this range, the charge control agent is detached from the surface of the toner during continuous use in the developing device, resulting in a large amount. The charge amount may change.

The core particles of the carrier coated with the silicone resin used in the present invention may be those conventionally known, for example, ferromagnetic metals such as iron, cobalt and nickel; magnetite, hematite, ferrite and the like. Alloys and compounds; glass beads and the like. The average particle size of these core particles is usually 10 to 1000 μm, preferably 30 to 500 μm. The amount of the silicone resin used is usually 1 to 10% by weight based on the carrier core particles.

As the silicone resin for coating the carrier core particles, conventionally known silicone resins are used. For example, commercially available products include KR261, KR271, KR272, KR275, manufactured by Shin-Etsu Silicone Co., Ltd.
KR280, KR282, KR285, KR251, K
R155, KR220, KR201, KR204, KR
205, KR206, SA-4, ES1001, ES1
001N, ES1002T, KR3093 or SR2100, SR2101, SR210 manufactured by Toray Silicone Co., Ltd.
7, SR2110, SR2108, SR2109, SR
2115, SR2400, SR2410, SR241
1, SH805, SH806A, SH840 and the like are used.

As a method for forming the silicone resin layer, the silicone resin may be applied to the surface of the carrier core particles by a method such as a spraying method or a dipping method as in the conventional method. Since this silicone-coated carrier has a low surface energy as described above, it is possible to extremely reduce the fusion of the toner on the surface due to long-term stirring in the developing device.

Further, it is particularly effective to use a carrier having a dynamic resistance (hereinafter referred to as DR) in the range of 1.0 × 10 ^{8 to} 2.0 × 10 ⁹ Ωcm as the carrier to be combined with the toner in the present invention. Is. By using a silicone-coated carrier in this DR range,
It is possible to obtain a high quality image. DR is 1.0 × 1
0 ⁸ Using silicone-coated carrier less than [Omega] cm, Q / M despite the high toner adhesion amount becomes excessive, collapsed image, a strong lead to deterioration of the resolution.
On the contrary, in the case of a silicone-coated carrier having a DR of more than 2.0 × 10 ⁹ Ωcm, the toner adhesion amount becomes small, the image density becomes low, and the edge effect becomes strong. DR adjustment is shown in Fig. 4.
This is possible by adjusting the amount of conductive carbon black added to the silicone coating layer, as shown in FIG.

As a method of measuring DR, a carrier used in a two-component dry developer is stirred by a sleeve containing a magnet, a DC voltage is applied from a doctor blade installed on the sleeve, and the sleeve is grounded. A method of measuring the flowing current value is adopted. According to this method, it is possible to measure all known carriers, whether they are non-coated carriers or coated carriers, as long as they are carriers used for two-component dry developers.

In the toner used in the present invention, a polyester resin is used as the binder resin, and a polyester resin synthesized from a bisphenol diol type alcohol and a monomer containing a polyvalent carboxylic acid as a main component is preferable. By using this type of polyester resin, a good toner can be obtained without impairing the vinyl chloride matting resistance and the color of the color material of the color toner. Of course, the fixability at low temperatures is also good. Polyester resin
It is usually obtained by polycondensing a polyol component and a polycarboxylic acid component at a temperature of 180 to 250 ° C in an inert gas atmosphere.

In the present invention, as release agents for toner, free fatty acid type carnauba wax having an acid value of 5 or less, montan ester wax and / or oxidized rice wax having an acid value of 10 to 30 is used. The free fatty acid-type carnauba wax in this case is one in which free fatty acids are desorbed using carnauba wax as a raw material, so that the acid value is 5% or less, and it becomes finer crystals than conventional carnauba wax. The dispersed particle size in the binder resin is 1 μm or less, and the dispersibility is improved.

The montan ester wax is refined from minerals and becomes fine crystals like the carnauba wax, and the dispersed particle diameter in the binder resin is 1 μm or less, and the dispersibility is improved. In the case of montan ester wax, the acid value is particularly preferably 5-14.
The oxidized rice wax is obtained by air-oxidizing rice bran wax. The acid value is preferably 10 to 30, and when it is less than 10, the lower limit fixing temperature rises and the low temperature fixability becomes insufficient, and when it is more than 30, the cold offset temperature rises and the low temperature fixability also becomes insufficient. These waxes may be used alone or in combination and may be 1 to 15% by weight of the total toner, preferably 2 to
Good results are obtained by containing 10% by weight.

Further, in the present invention, as the colorant used in the toner, all of the pigments and dyes conventionally used as the colorant for toner are applied. Specifically, carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, calcco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl methane series Any conventionally known dyes and pigments such as dyes and pigments may be used alone or in combination. The amount of these colorants used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the binder resin.

In the present invention, the toner may further contain a magnetic material to be used as a magnetic toner. In this case, the magnetic material contained in the magnetic toner includes iron oxide such as magnetite, hematite, and ferrite, iron,
Metals such as cobalt and nickel or these metals and aluminum, cobalt, copper, lead, magnesium, tin,
Examples thereof include alloys with metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

These ferromagnetic materials have an average particle size of 0.1 to 0.1.
2 μm or so is preferable, and the amount contained in the toner is about 20 to 200 with respect to 100 parts by weight of the resin component.
Parts by weight, particularly preferably 4 parts by weight per 100 parts by weight of the resin component
0 to 150 parts by weight.

The toner used in the present invention may be mixed with additives as required. As the additive, for example, a tetrafluoroethylene resin, a lubricant such as zinc stearate or cerium oxide, an abrasive such as silicon carbide, or a fluidity imparting agent such as colloidal silica or aluminum oxide, an anti-caking agent, or, for example, There are conductivity imparting agents such as carbon black and tin oxide.

[0031]

EXAMPLES Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. In addition, all parts and% shown below are based on weight.

Example 1 Polyester resin (number average molecular weight Mn = 5000, weight average molecular weight Mw = 55000, glass transition point Tg = 62 ° C.) 80 parts Styrene acrylic resin (Tg = 62 ° C .: acid value 2 or less) 20 parts Desorption Free fatty acid type carnauba wax (acid value 2) 5 parts Carbon black (Mitsubishi Carbon Co. # 44) 10 parts Charge control agent (compound represented by structural formula [I]) 0.5 parts

The mixture having the above composition was sufficiently stirred and mixed in a Henschel mixer, and then kneaded with a heated two-roll, and the obtained kneaded product was pulverized and classified to obtain a positively chargeable toner having a particle size of 5 to 20 μm. It was

Example 2 As the charge control agent in the formulation of Example 1, R ¹ = H, R ² = CH ₃ , R in the above structural formulas [II] and [III].
Particles of 5 to 20 μm were obtained in the same manner as in Example 1 except that the quaternary ammonium salt copolymer represented by ³ = C ₂ H ₅ , R ⁴ ═R ⁵ ═CH ₃ , and R ⁶ ═H was used. A positively chargeable toner having a diameter is obtained.

Example 3 As Example 1, except that the copolymer represented by R ¹ = H in the above structural formulas [II] and [IV] was used as the charge control agent in the formulation of Example 1. 5-20 in the same way
A negatively chargeable toner having a particle size of μm was obtained.

Comparative Example 1 Example 1 was repeated except that the compound represented by the following structural formula [V] was used as the charge control agent in the formulation of Example 1.
In the same manner as described above, a positively chargeable toner having a particle size of 5 to 20 μm was obtained.

[Chemical 5]

Comparative Example 2 As a charge control agent in the formulation of Example 1, the same procedure was carried out except that the compound represented by the following structural formula [VI], X = H, Y = Cl, Z = SO ₃ H was used. A negatively chargeable toner having a particle size of 5 to 20 μm was obtained in the same manner as in Example 1.

[Chemical 6]

With respect to the above-obtained five types of toners, the environmental dependency of the charge amount of the developer (the ratio of change of the charge amount with respect to the change of temperature and humidity) was measured. The results are shown in Table 1.
Shown in. The carrier particles used here are TEFV.
200/300 (manufactured by Nippon Steel Co., Ltd.), and how to determine the environmental dependency of the charge amount of the developer is as follows.

(How to Determine Environmental Dependence of Charge Amount of Developer) The environmental dependency is expressed as a variation rate between the low-temperature low-humidity charge amount and the high-temperature high-humidity charge amount. (A) Low-temperature low-humidity charge amount In a low-temperature low-humidity chamber at 10 ° C. and 20% relative humidity (RH), 3.0 g of toner and 97.0 g of carrier are conditioned for 3 hours. After that, the toner and the carrier are put in a 120 ml stainless steel pot and stirred for 10 minutes, and the charge amount is obtained by the blow-off method. (B) High temperature and high humidity charge amount In a high temperature and high humidity chamber of 30 ° C. and 85% RH, toner 3.
The humidity of 0 g and 97.0 g of carrier is adjusted for 3 hours. afterwards,
The toner and carrier are put into a 120 ml stainless steel pot, stirred for 10 minutes, and the charge amount is determined by the blow-off method.

[0040]

[Table 1]

From the results shown in Table 1, it can be seen that the developer of the present invention has very little variation in the charge amount of the developer due to the environment.

Examples 4 to 10 and Comparative Example 3 In the formulation of Example 1, the content of the charge control agent (0.5
A positively chargeable toner having a particle size of 5 to 20 μm was prepared in the same manner as in Example 1 except that the (part) was changed as shown in Table 2 below.

[0043]

[Table 2]

When the charge amounts of the toners obtained in Examples 1, 4 to 10 and Comparative Example 3 were measured, the results shown in FIG. 1 were obtained. From FIG. 1, when the charge control agent represented by the structural formula [I] of the present invention is used, the content of the charge control agent is 0.5 to 5 parts with respect to 100 parts of the resin content in the toner. It can be seen that the optimum charge amount can be obtained.

Further, with respect to each of the above toners, the environmental dependency of the charge amount of the developer was measured. The results are shown in Table 3.

[0046]

[Table 3]

From the results shown in Table 3, it can be seen that the smaller the content of the charge control agent, the better the environmental stability. However, if the content is too small, a sufficient charge cannot be obtained, and it is necessary to contain at least 0.5 part.

Examples 11 to 17 In the formulation of Example 2, the content of the charge control agent (0.5
A positively chargeable toner having a particle size of 5 to 20 μm was prepared in the same manner as in Example 2 except that (part) was changed as shown in Table 4 below.

[0049]

[Table 4]

As to the toners obtained in Example 2 and Examples 11 to 17, the amount of charge was measured.
The results shown in are obtained. From FIG. 2, even when the charge control agent represented by the structural formulas [II] and [III] of the present invention is used, the content of the charge control agent is 0.5 to 5 relative to 100 parts of the resin content in the toner. It can be seen that the optimum charge amount can be obtained within the range of parts.

Further, with respect to each of the above toners, the environmental dependence of the charge amount of the developer was measured. The results are shown in Table 5.

[0052]

[Table 5]

From the results in Table 5, it can be seen that the smaller the content of the charge control agent, the better the environmental stability. However, if the content is too small, a sufficient amount of charge cannot be obtained, and it is necessary to contain at least 0.5 part.

Examples 18 to 24 and Comparative Example 4 In the formulation of Example 3, the content of the charge control agent (0.5
A negatively chargeable toner having a particle size of 5 to 20 μm was prepared in the same manner as in Example 3 except that the (part) was changed as shown in Table 6 below. (However, the toner of Comparative Example 4 containing no charge control agent has a positive chargeability.)

[0055]

[Table 6]

Example 3, Examples 18-24 and Comparative Example 4
When the charge amount of the toner obtained in (1) was measured, the results shown in FIG. 3 were obtained. From FIG. 3, even when the charge control agents represented by the structural formulas [II] and [IV] of the present invention are used, the resin content in the toner is 100 parts by weight.
It can be seen that the optimum charge amount can be obtained within the range of the charge control agent content of 0.5 to 5 parts.

Further, with respect to each of the above toners, the environmental dependence of the charge amount of the developer was measured. The results are shown in Table 7.

[0058]

[Table 7]

From the results in Table 7, it can be seen that the smaller the content of the charge control agent, the better the environmental stability. However, if the content is too small, a sufficient charge cannot be obtained, and it is necessary to contain at least 0.5 part.

Example 25 To 3 parts of the toner obtained in Example 1, a silicone-coated carrier [containing 0.02% by weight of Ketjen Black (manufactured by Lion Akzo Co., Ltd. in a silicone resin coating): DR = 6] 0.0 × 10 ⁸ Ωcm] (97 parts) was mixed with a ball mill to obtain a two-component developer. The charge amount of the toner was +20 μC / g.

Examples 26 to 31 Two-component type developers were obtained in the same manner as in Example 25 except that silicone coated carriers having DR as shown in Table 8 below were used.

[0062]

[Table 8]

Example 32 A two-component type developer was obtained in the same manner as in Example 25 except that the toner obtained in Example 2 was used in place of the toner obtained in Example 1. Obtained. The charge amount of the toner was +20 μC / g.

Examples 33 to 38 Two-component type developers were obtained in the same manner as in Example 32 except that silicone coated carriers having DR as shown in Table 9 below were used.

[0065]

[Table 9]

Example 39 A two-component type developer was prepared in the same manner as in Example 25 except that the toner obtained in Example 3 was used in place of the toner obtained in Example 1. Obtained. The toner charge amount was −18 μC / g.

Examples 40 to 45 Two-component type developers were obtained in the same manner as in Example 39 except that the silicone coated carrier having DR shown in Table 10 below was used.

[0068]

[Table 10]

Comparative Examples 5 to 7 In Examples 25, 32 and 39, instead of the silicone coated carrier, PMMA coated carrier (DR =
A two-component type developer was obtained in the same manner as in Examples 25, 32 and 39, except that 2.0 × 10 ⁹ Ωcm) was used.

(Image Evaluation) The two-component type developers obtained in Examples 25 to 45 and Comparative Examples 5 to 7 were subjected to image evaluation using a plain paper copying machine (FT-4420 manufactured by Ricoh Co., Ltd.). The obtained results are shown in Tables 11-12. The measuring method of each item is as follows.

(A) Image density Measurement was carried out using RD-514 type manufactured by Macbeth. (B) Gradation Judgment was made using a gray scale manufactured by Kodak. (C) Background stain The judgment was made using a document having a Macbeth density of 0.07. (D) Poor manuscript reproducibility Judgment was made using manuscripts of different density. (E) Spent property 97 parts of the carrier and 3 parts of the toner were put in a 100 ml stainless pot and continuously stirred for 24 hours to evaluate the spent property. The amount of spent is measured by blowing off the developer after stirring for 24 hours, expelling the adhered toner by electrostatic force, and measuring the weight (W ₁ ). Next, the fused material is dissolved in toluene and the weight is measured (W ₂ ). The amount of spent is calculated by the following formula. Spent amount (%) = [(W ₁ −W ₂ ) / W ₁ ] × 100 0-0.01%: ◎ 0.01-0.02%: ○
0.02-0.05%: △ 0.05% <: x

[0072]

[Table 11] ◎: Very good ○: Good △: Poor ×: Very bad

[0073]

[Table 12] ◎: Very good ○: Good △: Poor ×: Very bad

From the results shown in Tables 11 and 12, it was found that the developer of the present invention gave a good quality image.
It can be seen that a higher quality image can be obtained by using the silicone-coated carrier having R in the range of 1.0 × 10 ^{8 to} 2.0 × 10 ⁹ Ωcm. It is also clear that the silicone-coated carrier has excellent spent property.

[0075]

The developer according to claim 1 comprises a carrier coated with a silicone resin and a toner containing a binder resin, a release agent and a charge control agent as main components, and the toner serves as the binder resin. Polyester resin with an acid value of 5 as a release agent
The following free fatty acid type carnauba wax, montan ester wax and / or oxidized rice wax having an acid value of 10 to 30 and the above-mentioned structural formula [I], structural formulas [II] and [III] as a charge control agent ] And at least one of the compounds represented by the structural formulas [II] and [VI], the composition has sufficient offset resistance and wrapping resistance at the time of fixing, and has a lower limit fixing temperature. Sufficiently low, the dispersibility of the release agent in the binder resin is good, there is no toner filming or carrier contamination during development, and the environment dependence of the developer charge amount is extremely small. A stable and high-quality image can be formed.

Since the developer according to claim 2 has a constitution in which the dynamic resistance of the carrier is 1.0 × 10 ^{8 to} 2.0 × 10 ⁹ Ωcm, the quality of the image formed is further improved. The effect is added.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the toner charge amount and the charge control agent content in the toner.

FIG. 2 is a graph showing the relationship between the toner charge amount and the charge control agent content in the toner.

FIG. 3 is a graph showing the relationship between the toner charge amount and the charge control agent content in the toner.

FIG. 4 is a graph showing the relationship between the amount of carbon black in the silicone resin coating and the dynamic resistance of the carrier.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI Technical display location G03G 9/113 G03G 9/08 365 365 9/10 352 (72) Inventor Yoshihiro Suguro Nakamagome 1-chome, Ota-ku, Tokyo No. 3-6 Ricoh Co. Ltd.

Claims (2)

[Claims] 1. A developer comprising a carrier coated with a silicone resin and a toner containing a binder resin, a release agent and a charge control agent as a main component, and containing at least a polyester resin as the binder resin of the toner. In addition, as a releasing agent, a free fatty acid type carnauba wax having an acid value of 5 or less, a montan ester wax and / or an acid value of 10
A developer for developing an electrostatic charge image, which contains 30 oxidized rice wax and further contains at least one of the compounds represented by the following (1) to (3) as a charge control agent. (1) CIPigment Red 81 represented by the following structural formula [I]
Compounds classified into. [Chemical 1] (2) It has structural units represented by the following structural formulas [II] and [III], and the ratio of [II] and [III] is 65: 35-9.
7: 3 quaternary ammonium salt copolymer compound. [Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ] [Chemical 3] [In the above formula, R ^{2 to} R ⁶ represent the following, respectively. R ² : hydrogen atom or methyl group. R ³ : an alkylene group. ^{R 4, R 5, R 6} : an alkyl group. (3) It has structural units represented by the following structural formulas [II] and [IV], and the ratio of [II] and [IV] is 65: 35-9.
Copolymer compound of 7: 3. [Chemical 2] [In the above formula, R ¹ represents a hydrogen atom or a methyl group. ] [Chemical 4] 2. The dynamic resistance of the carrier coated with the silicone resin is 1.0 × 10 ^{8 to} 2.0 × 1.
The developer for developing an electrostatic charge image according to claim 1, which has a resistance value of 0 ⁹ Ωcm.