JPH086296A - Toner for developing electrostatic charge image and electrophotographic developer using the same - Google Patents

Abstract

PURPOSE:To impart stable triboelectric chargeability to a toner based on a resin binder, a colorant and an electric charge controlling agent and to remarkably suppress a variation of the chargeability due to environment by further incorporating an electric charge controlling agent whose polarity is reverse to that of the toner into the toner. CONSTITUTION:In a toner based on a resin binder, a colorant and a positive or negative electric charge controlling agent, an electric charge controlling agent whose polarity is reverse to that of the toner is used in combination. Any conventional electric charge controlling agent may be used as the positive or negative electric charge controlling agent and the amt. of this agent used depends on the kind of the resin binder, the presence of additives used at need and a method for producing the toner including a dispersing process. The electric charge controlling agent whose polarity is reverse to that of the toner is used by 0.1-1 pt. wt., preferably 0.2-0.5 pt.wt. per 100 pts.wt. of the resin binder. Polystyrene, poly-p-chlorostyrene or a mixture of them may be used as the resin binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic charge image used in electrophotography, electrostatic printing and the like and a two-component electrophotographic developer using the toner.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 61-147261, a method of developing an electrostatic charge image by using toner is roughly classified into a so-called two method in which a toner and a carrier are mixed. There are a method of using a component type developer and a method of using a one component type developer which is used alone as a toner without being mixed with a carrier. In the former two-component developing method, the toner and the carrier are stirred and rubbed so that they are charged to different polarities, and an electrostatic charge image having an opposite polarity is visualized by the charged toner. Depending on the type of carrier, there are a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method, and the like. The latter one-component developing method includes a powder cloud method in which toner particles are sprayed and used, a contact developing method in which toner particles are directly brought into contact with an electrostatic latent image surface to develop (also referred to as touchdown development), There is an induction developing method in which a magnetic conductive toner is brought into contact with the electrostatic latent image surface.

As the toner applied to these various developing methods, fine powder in which a colorant such as carbon black is dispersed in a binder resin made of a natural resin or a synthetic resin is used. For example, a binder resin such as polystyrene in which a colorant is dispersed is 1 to 30.
Particles finely pulverized to about μm are used as toner. Further, a magnetic toner such as those containing a magnetic material such as magnetite is used as a magnetic toner.

As described above, the toner used in various developing methods has positive or negative electric charge depending on the polarity of the electrostatic image to be developed. In order to make the toner have electric charge, It is possible to utilize the triboelectric charging property of the resin which is a component of the toner, but since the toner has a low charging property in this method, the image obtained by development is apt to be fogged and unclear. Therefore, in order to impart a desired triboelectric charging property to the toner, a dye that imparts the charging property,
A pigment or a charge control agent is added.

Conventionally, as negative charge control agents, metal complex salts of monoazo dyes, nitrohumic acid and its salts, salicylic acid, naphthoic acid, dicarboxylic acids such as Fe, Co and N.
Examples thereof include metal complexes of i, Cr and Zn, sulfonated copper phthalocyanine pigments, nitro groups, halogen-introduced styrene oligomers, chlorinated paraffins and melamine resins. In addition, as positive charge control agents, nigrosine, 4
There are primary ammonium salts, lake pigments, imidazole derivatives, guanidine compounds, etc., but these compounds have a complicated structure, their properties are not constant, and their stability is poor. Further, during thermal kneading, decomposition or mechanical shock, friction, changes in temperature and humidity conditions, and the like are likely to cause decomposition or deterioration, and a phenomenon in which charge controllability is deteriorated is likely to occur. Also, in many cases, the chargeability changes depending on the environment.

Recently, a polyester resin or an epoxy resin has been often used as a binder resin because of its advantages such as vinyl chloride mat fusion resistance, storage stability and low temperature fixability. However, if a polyester resin or epoxy resin is used as a binder resin in a toner and is used in combination with a conventional charge control agent, the charge amount is low in either case, or even if it is high, the charge amount decreases with repeated use. However, there is a problem that it is difficult to use because of fog and toner scattering. It is considered that this is because functional groups such as —COOH group and —OH group remain in the polyester resin and the epoxy resin due to their chemical structures, which hinders maintaining stable chargeability.

Conventionally, as a mechanism of a two-component dry developer, fine toner particles are formed on the surface of relatively large particles.
It is held by the electric force generated by the friction of both particles, and when the electrostatic latent image is approached, the attraction force in the latent image direction to the toner particles by the electric field formed by the electrostatic latent image is generated between the toner particles and the carrier particles. It has been proposed that the toner particles are attracted and adhered onto the electrostatic latent image to make the electrostatic latent image visible by overcoming the binding force of. Since the developer is repeatedly used while replenishing the toner consumed by the development, the carrier must always frictionally charge the toner particles to a desired polarity and a sufficient charge amount during long-term use. .

However, in the conventional developer, a toner film is formed on the surface of the carrier by mechanical collision such as collision between particles, collision between particles and developing machine, or heat generated by these effects, so-called spent formation. Then, the charging characteristics of the carrier deteriorate with the time of use, and it becomes necessary to replace the entire developer.

In order to prevent such spent formation,
Conventionally, a method of coating various resins on the carrier surface has been proposed, but a satisfactory method has not been obtained yet. For example, a carrier coated with a resin such as a styrene-methacrylate copolymer or a styrene polymer has excellent charging characteristics, but has a relatively high critical surface tension on the surface, and therefore, after repeated copying, a spent state may occur. The life as a developer was not so long.

On the other hand, a carrier coated with a silicone resin having a low surface tension has been proposed. However, since the silicone resin has a weak mechanical strength, strong stirring such as in a high-speed copying machine or inside a developing section is required. By stirring for a long time at
When the carrier particles collide with the inner wall of the developing unit or the surface of the photoconductor, or when the particles collide with each other, the silicone resin coating layer is worn or peeled off with time, and frictional electrification is caused by the electrification between the toner and the silicone resin. Since the charge between the carrier core particles changes, the charge amount of the developer cannot be kept constant, and there is a problem that the image quality deteriorates. Further, when the carrier particles are coated with a silicone resin, the silicone resin itself has a high electric resistance, so that when it is used as a developer, the image quality is deteriorated due to an edge phenomenon and a charge accumulation phenomenon.

The drawbacks of such a coated carrier can be ameliorated by dispersing a conductive substance in the coating layer. That is, when the carrier is given a certain degree of conductivity, the carrier acts as a developing electrode, and the development is carried out in a state where the developing electrode and the surface of the photoconductor to be developed are in close contact with each other. Even a large area of black area is faithfully reproduced as the original.

Conventionally, carbon, tin oxide, etc. have been used as such a conductive material, but when such a conductive material is dispersed in a coating layer of a carrier, the following drawbacks occur. Generally, the toner and the carrier are charged when they contact each other. In this case, when the electric resistance of the carrier becomes small, the charge generated in the toner is attenuated through the carrier, and the charge amount cannot be maintained. Further, there is a problem that the conductive material is separated from the coating layer due to use over time and the charge amount changes. In order to solve this problem, Japanese Patent Laid-Open No. 182759/1987 improves the treatment by treating carbon with aminosilane, amino-modified silicone oil or the like, but the cost increases due to an increase in treatment steps. Met.

[0013]

SUMMARY OF THE INVENTION The present invention provides a toner for developing an electrostatic charge image which has stable triboelectric chargeability and has little change in chargeability due to the environment, and a high-quality toner using the toner. It is an object of the present invention to provide a two-component electrophotographic developer that can obtain an image and has excellent durability.

[0014]

As a result of intensive investigations, the inventors of the present invention have found that when a toner for developing an electrostatic image is used in combination with a charge control agent having a polarity opposite to that of the toner, the charge amount of the toner is reduced. Found that environmental stability was improved,
The present invention has been completed. That is, according to the present invention, in a toner for developing an electrostatic image containing a binder resin, a colorant and a charge control agent as a main component, a charge control agent having a polarity opposite to that of the toner is used in combination. A toner for developing a charge image is provided. In particular, there is provided the positively chargeable toner for developing an electrostatic charge image, wherein the binder resin is a polyester resin, an epoxy resin, or a polyol resin obtained by modifying an epoxy resin. Further, according to the present invention, in a two-component electrophotographic developer comprising the toner and a carrier, the carrier has a silicone resin coating layer containing conductive fine powder and a silane coupling agent. An electrophotographic developer is provided.

As the positive or negative charge control agent used in the present invention, all conventional charge control agents can be used. Examples of the positively chargeable charge control agent include Orient Chemical Co., Nigrosine EX, Bontron P-51, Hodogaya Chemical Co., TP-302, and Fujikura Kasei FCA-201-PB, but are not limited thereto. is not. As the negatively chargeable charge control agent, Orient Chemical Co., S-34, E-84, E-89, Hodogaya Chemical Co., Spiron Black T-95, Aizen Color T-77, T are used.
Examples thereof include RH and Fujikura Kasei FCA-1001-N, but the invention is not limited thereto.

In the present invention, the amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. However, it is preferably 0.1 to 100 parts by weight of the binder resin.
Used in the range of 10 parts by weight. The preferred range is 2 to 5 parts by weight. If the amount is less than 0.1 parts by weight, the negative charging of the toner is insufficient, which is not practical. If it exceeds 10 parts by weight, the chargeability of the toner is too great, and the electrostatic attraction with the carrier increases, resulting in a decrease in the fluidity of the developer and a decrease in the image density. Moreover, you may use together with another charge control agent as needed.

The amount of the charge control agent having a polarity opposite to that of the toner is 0.1 to 1 with respect to 100 parts by weight of the binder resin.
It is advisable to add parts by weight, preferably 0.2 to 0.5 parts by weight. If the amount is more than 1 part by weight, the amount of the opposite polarity toner particles is large, so that fog occurs. If the amount is less than 0.1 part by weight, the effect is not exhibited.

As the binder resin used in the present invention, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, or a substitution product thereof is used.
Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer Coalesce, styrene-butyl methacrylate copolymer,
Styrene-α-chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Styrene-based copolymers such as styrene-maleic acid copolymers and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester,
Polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. , And can be used alone or as a mixture.

As examples of binder resins suitable for pressure fixing, the following may be used alone or in combination. Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resin, polyester resin, styrene-butadiene copolymer (monomer ratio 5 to 3)
0: 95-70), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl chloride Copolymers, ethylene-vinyl acetate copolymers, ionomer resins), polyvinylpyrrolidone resins and the like.

Further, in the present invention, a polyester resin or an epoxy resin, which is excellent in vinyl chloride mat fusion resistance, storage stability and low temperature fixability, but has a problem in terms of charging property is used as a binder resin. However, it has a good charging property and is most suitable as a low temperature fixing toner.

The polyester resin used in the present invention is obtained by polycondensation of polyhydric alcohol and polycarboxylic acid. For example, the polyhydric alcohol may be polyethylene glycol, diethylene glycol, triethylene glycol, 1,2. -Propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,4-butenediol and other diols, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, etherified bisphenols such as polyoxypropyleneized bisphenol A, divalent alcohol monomers obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, and other divalent alcohols Body, sorbitol, 1,2,3,6-hexane Troll, 1,4-salbitan, pentaethritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol Examples thereof include trihydric or higher polyhydric alcohol monomers such as 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

The polycarboxylic acid used to obtain the polyester resin is, for example, maleic acid,
Fumaric acid, mesaconic acid, citraconic acid, itaconic acid,
Glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, malonic acid, divalent ones obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms Carboxylic acid monomers, anhydrides of these acids, dimers of lower alkyl esters and linoleic acid, other divalent carboxylic acid monomers, 1,2,4-benzenetricarboxylic acid, 1,2,5 -Benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,
2,5-hexanetricarboxylic acid, 1,3-dicarboxylic-2-
Trivalent or higher polyvalent carboxylic acids such as methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, embol trimer acid, and anhydrides of these acids. Examples thereof include monomers, and monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid may be used in combination.

The epoxy resin used in the present invention is a polycondensation product of bisphenol A and epichlorohydrin, for example, Epomic R362, R364, R36.
5, R366, R367, R369, (Mitsui Petrochemical Industry Co., Ltd.), Epotote YD-011, YD-012, YD-014, YD-904, YD-017, (Toto Kasei Co., Ltd.), Epicoat 1002, 1004, 1007 (manufactured by Shell Chemical Co.)
Commercially available products can be used. Further, a polyol resin obtained by reacting these epoxy resin terminal glycidyl groups with a compound having one active hydrogen such as monovalent phenol or secondary amine can also be used. By reacting the terminal glycidyl group in advance, it is possible to prevent reaction with other materials during kneading, and to avoid biochemical problems such as sensitization.

As the compound having one such active hydrogen, a monovalent phenol or a secondary amine can be used as described above. Examples of the monovalent phenol include phenol, cresol, isopropylphenol, aminophenol, nonylphenol, Examples thereof include p-cumylphenol, and examples of the secondary amine include diethylamine, dibutylamine, ethyleneimine, piperidine, piperazine, and the like.

Examples of the colorant used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, hansa yellow G and rhodamine 6.
G, lake, chalco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes, dyes and pigments can be used alone or in combination. obtain.

Further, the toner of the present invention further contains a magnetic material and can be used as a magnetic toner. The magnetic material contained in the magnetic toner of the present invention includes magnetite, hematite, iron oxide such as ferrite, metals such as iron, cobalt, nickel, or aluminum of these metals,
Examples thereof include alloys of metals such as cobalt, copper, lead, magnesium, tin, 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 2 μm.
It is desirable that the amount is about 20 to 200 parts by weight based on 100 parts by weight of the resin component, and particularly preferably 40 to 40 parts by weight based on 100 parts by weight of the resin component.
It is 150 parts by weight.

Further, the toner of the present invention may be mixed with additives as required. Examples of the additives include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, fluidity imparting agents such as colloidal silica and aluminum oxide, anti-caking agents, or carbon black, tin oxide. And the like, or a fixing aid such as a low molecular weight polyolefin.

Further, when the toner of the present invention is used as a two-component type developer, it is used as a mixture with carrier powder. As such carrier powder, all known powders can be used, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads and the like, and those whose surface is treated with resin or the like. Is mentioned. The carrier powder is preferably coated with a silicone resin containing a conductive fine powder and a silane coupling agent.
The carrier core particles coated with the silicone resin in the present invention may be those conventionally known, and examples thereof include ferromagnetic metals such as iron, cobalt and nickel; alloys and compounds such as magnetite, hematite and ferrite; glass beads and the like. To be The average particle size of these core particles is usually 10
˜1000 μm, preferably 30 to 500 μm.

In the present invention, the silicone resin forming the coating layer of the carrier particles may be any conventionally known silicone resin, for example, commercially available KR261 and K manufactured by Shin-Etsu Silicone Co., Ltd.
R271, KR272, KR275, KR280, KR
282, KR285, KR251, KR155, KR2
20, KR201, KR204, KR205, KR20
6, SA-4, ES1001, ES1001N, ES1
002T, KR3093 and SR2100, SR2101, SR2107 manufactured by Toray Dow Corning Silicone Co., Ltd.
SR2110, SR2108, SR2109, SR21
15, SR2400, SR2410, SR2411, S
H805, SH806A, SH840 and the like are used.
The amount of the silicone resin used is usually 1 to 10% by weight based on the carrier core particles.

The conductive fine powder to be dispersed in the coating layer may be conventionally known carbon black, such as contact black, furnace black and thermal black. The conductive fine powder has a thickness of 0.01 to 5.0 μm.
The particle size is preferably about 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the silicone resin.

The silane coupling agent used in the present invention is, for example, the following general formula:

Embedded image A compound represented by X—Si (OR) ₃ (wherein, X represents a functional group that reacts with an organic substance, and R represents a hydrolyzable group), and 100 parts by weight of a silicone resin is used. 0.1 to 10 parts by weight,
It is preferable to add 0.2 to 5 parts by weight.

The coating layer-forming composition is prepared by adding the conductive fine powder and the silane coupling agent to a silicone resin solution and dispersing them with an appropriate mixer. Further, as a method for forming the silicone resin layer, the silicone resin composition for forming the coating layer 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.

As described above, since the silicone resin coating layer of the carrier contains the conductive fine powder such as carbon black and the silane coupling agent such as the aminosilane coupling agent, the carrier has durability, and edge phenomenon and It is possible to obtain a two-component developer for electrophotography, which does not deteriorate image quality due to the phenomenon of charge accumulation and exhibits stable triboelectric chargeability even when used over time. Further, the present invention, by coating the surface of the core particles with a silicone resin containing a conductive fine powder and a silane coupling agent, to maintain the same advantages of the conventional silicone resin coated carrier,
By imparting conductivity to the carrier, the phenomenon of charge accumulation in the carrier, peeling of the coating layer, and detachment of the conductive fine powder are effectively suppressed.

A developing method using the developer of the present invention will be described. In the developing device shown in FIG. 1, the toner tank 7
The toner 6 contained in the toner is forced to the sponge roller 4 by the stirring blade 5, and the toner is supplied to the sponge roller 4. The toner taken into the sponge roller 4 is conveyed to the toner conveying member 2 by the rotation of the sponge roller in the arrow direction, and is rubbed and electrostatically or physically adsorbed, and the toner conveying member 2 is moved in the arrow direction. It strongly rotates, and the elastic blade 3 forms a uniform thin toner layer and is triboelectrically charged. After that, the electrostatic latent image carrier 1 that is in contact with or in close proximity to the toner conveying member 2
And is transferred to the surface of, where the latent image is developed.

[0035]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, a part represents a weight part.

Production of polyol resin [Synthesis example of polyol resin A] Bisphenol A type epoxy resin (Mn; about 3500) 94 parts p-cresol 6 parts Xylene 20 parts The above raw materials were put in a separable flask and heated to 90 ° C. . Furthermore, 0.015 parts of lithium chloride was added to give 170
The reaction was carried out for 10 hours while distilling off xylene at ℃. The obtained solid was dissolved in MEK and reprecipitated in hexane to obtain a purified polyol resin A.

[Synthesis Example of Polyol Resin B] Bisphenol A type epoxy resin (Mn; about 3200) 88 parts p-cumylphenol 12 parts xylene 20 parts The above raw materials were placed in a separable flask and heated to 90 ° C. Furthermore, 0.015 parts of lithium chloride was added to give 170
A solid substance obtained by reacting for 10 hours while distilling off xylene at 0 ° C. was dissolved in MEK and reprecipitated in hexane to obtain a purified polyol resin B.

Carrier Production Example Next, a production example of a carrier having several silicone resins in a coating layer will be shown. These can be performed by known means. [Production Example of Carrier A] Composition of coating layer forming liquid A Silicon resin solution (KR250 manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts Toluene 100 parts A mixture of the above composition was dispersed for 30 minutes with a homomixer to prepare coating layer forming liquid A. . Carrier A in which a coating layer is formed on the surface of 1000 parts of spherical ferrite having an average particle diameter of 100 μm using this coating layer forming liquid using a fluidized bed type coating apparatus
I got

[Production Example of Carriers B, C, D and E] The following components were mixed with 100 parts of toluene and dispersed with a homomixer for 30 minutes to prepare coating layer forming liquids. Composition of coating layer forming liquid B Silicone resin (KR206 Shin-Etsu Silicone) 100 parts Carbon black (# 44 Mitsubishi Kasei) 3 parts Composition of coating layer forming liquid C Silicone resin (SR2400 Toray Dow Corning Silicone) 100 parts Tin oxide (S- 1 Mitsubishi Metals 2 parts Composition of coating layer forming liquid D Silicone resin (SR2400 Toray Dow Corning Silicone) 100 parts Carbon black (# 44 Mitsubishi Kasei) 1 part Methyltrimethoxysilane (SZ6070 Toray Dow Corning Silicone) 0.5 parts Composition of coating layer forming liquid E Silicone resin (KR206 Shin-Etsu Silicone) 100 parts Carbon black (# 44 Mitsubishi Kasei) 1.5 parts γ- (2-aminoethyl) aminopropylmethyldimethoxy silane (SH6020 Toray Dow Corning Silicone) 0.4 parts 0.4 parts The carrier B, C, D, E having a coating layer formed on the surface of 1000 parts of spherical ferrite having an average particle diameter of 70 μm using a fluidized bed type coating device using each coating layer forming liquid did.

Example 1 Styrene-2-ethylhexyl acrylate copolymer 100 parts Carbon black 8 parts Orient Chemical P-51 3 parts Orient Chemical E-89 0.2 parts The mixture having the above composition was sufficiently stirred in a Henschel mixer. After mixing, roll mill at a temperature of 130-140 ° C for about 3
After heating and melting for 0 minutes and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a toner having a particle diameter of 5 to 20 μm. 2.5 parts of this toner was mixed with 97.5 parts of 100-250 mesh iron powder carrier in a ball mill to obtain a developer. Next, the above developer was set in FT7570 manufactured by our company, and development was performed. As a result, a good image was obtained, and the image did not change even after printing 80,000 sheets. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was 20.6 μC / g, and the toner charge amount after running 80,000 sheets was 19.5 μC / g, which is almost the same as the initial value. There wasn't. Moreover, even in a low humidity environment of 10 ° C. and 15% RH and in a high humidity environment of 35 ° C. and 90% RH,
An image equivalent to normal humidity was obtained. 10 ℃ at the beginning, 1
The charge amount at 5% RH was 21.1 μC / g,
The charge amount at 90 ° C. and 90% RH is 19.0 μC / g,
There was almost no difference. There was also no toner filming on the photoconductor.

Example 2 A toner was prepared in the same manner as in Example 1 except that the carrier A was used.
When a developer was prepared and the same image output test was carried out, a good image was obtained, and the image did not change after 100,000 images were output. When the charge amount of the toner was measured by the blow-off method, the initial charge amount was 21.5 μC /
The charge amount of the toner after running 100,000 sheets was 19.9 μC / g, which was almost the same as the initial value. Also, in a low humidity environment of 10 ° C. and 15% RH and 35
Even in a high humidity environment of 90 ° C. and 90% RH, an image equivalent to normal humidity was obtained. The charge amount at 10 ° C. and 15% RH in the initial stage was 22.3 μC / g, and the charge amount at 35 ° C. and 90% RH was 21.4 μC / g, showing almost no difference. There was also no toner filming on the photoconductor.

Example 3 Polyol resin A 100 parts Carbon black 8 parts Hodogaya Kagaku T-95 2 parts Hodogaya Kagaku TP-302 0.1 part The raw material mixture having the above composition was melt-kneaded in the same manner as in Example 1. ,
After cooling, crushing and classification, a toner having a particle size of 5 to 25 μm was obtained. 2.5 parts of this toner was mixed with 97.5 parts of carrier B coated with a silicone resin in a ball mill,
A developer is obtained. Next, this developer was set in a copier FT7570 manufactured by our company in the same manner as in Example 1, and an image test was carried out. As with Example 1, a good image with high sharpness was obtained. It didn't change even after displaying 10,000 images. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −21.4 μC / g.
Toner charge amount after running 10,000 sheets is -20.3
There was almost no difference between μC / g and the initial value. Again 10
℃, low humidity environment of 15% RH and 35 ℃, 90% R
Even under a high humidity environment of H, an image equivalent to normal humidity was obtained. The charge amount at 10 ° C and 15% RH in the initial stage is -2
The charging amount was 2.4 μC / g, and the charge amount at 35 ° C. and 90% RH was −21.3 μC / g, showing almost no difference.
There was also no toner filming on the photoconductor.

Example 4 Polyol resin B 100 parts Carbon black 8 parts Fujikura Kasei FCA-1001-N 5 parts Fujikura Kasei FCA-201-PB 0.2 parts As in Example 1, Henschel was mixed with the above composition. After thoroughly stirring and mixing in a mixer, roll mill to 130-1
After heating and melting at a temperature of 40 ° C. for about 30 minutes and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a black toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 3 parts of silicon carbide (particle size: 2 μm) and 0.1 part of hydrophobic colloidal silica were sufficiently stirred and mixed with a speed kneader to obtain a toner. This toner was loaded into a developing device as shown in FIG. 1, continuous copying was carried out, and an image test was conducted. The electrostatic latent image was obtained by applying a negative DC charge of 800 V to the organic photoreceptor, exposing the latent image to form a latent image, and performing reversal development. The image did not change after 40,000 images were printed. Further, the specific charge amount of the toner on the toner conveying member:
In order to measure Q / M, the toner on the toner conveying member is sucked through a Faraday cage equipped with a filter layer on the outlet side, and the specific charge of the toner trapped in the Faraday cage is measured. With the quantity measuring device,
When Q / M was measured, it was confirmed that sufficient charge of -17.3 μC / g was made. In addition, the charge amount in running 40,000 sheets was -16.4 μC / g, which was almost the same as the initial value. Further, even under low and high humidity, image quality equivalent to normal humidity was obtained. Initially 10 ℃, 15
The charge amount at% RH was -18.1 μC / g, and was 35
The charge amount at 90 ° C. and 90% RH was −17.3 μC / g, and there was almost no difference. There was also no toner filming on the photoconductor. Also, there was no toner filming on the photoconductor.

Example 5 Polyester resin (Luna Pale 1447 manufactured by Arakawa Chemical Co., Ltd.) 100 parts Polypropylene 5 parts Carbon black 8 parts Hodogaya Chemical TP-302 3 parts Orient Chemical E-89 0.2 parts A raw material mixture having the above composition was used. As in Example 1, melt kneading,
After cooling, crushing and classification, a black toner having a particle size of 5 to 25 μm was obtained. 2.5 parts of this toner was mixed with 97.5 parts of carrier D coated with a silicone resin in a ball mill to obtain a developer. Next, this developer was set in a copier FT7570 manufactured by our company in the same manner as in Example 1, and an image test was performed. As with Example 1, a good image with high fidelity was obtained, and the image was 15 It didn't change even after displaying 10,000 images. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was 22.9 μC / g, and
The toner charge amount after running 50,000 sheets is 21.8.
There was almost no difference between μC / g and the initial value. Again 10
℃, low humidity environment of 15% RH and 35 ℃, 90% R
Even under a high humidity environment of H, an image equivalent to normal humidity was obtained. The initial charge amount at 10 ° C and 15% RH is 2
The charge amount was 3.4 μC / g, and the charge amount at 35 ° C. and 90% RH was 21.9 μC / g, showing almost no difference. There was also no toner filming on the photoconductor.

Example 6 Polyester resin (Luna Pale 1447 manufactured by Arakawa Chemical Co., Ltd.) 100 parts Polypropylene 5 parts Carbon black 8 parts Orion Chemical E-84 5 parts Orient Chemical P-51 0.2 parts The raw material mixture having the above composition was carried out. Melt kneading, as in Example 1,
After cooling, crushing and classification, a black toner having a particle size of 5 to 25 μm was obtained. 2.5 parts of this toner was mixed with 97.5 parts of carrier E coated with a silicone resin in a ball mill to obtain a developer. Next, this developer was set in a copying machine FT7570 manufactured by our company as in Example 1 and an image test was conducted. As with Example 1, a good image with high fidelity was obtained. It didn't change even after displaying 10,000 images. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −21.8 μC / g,
The toner charge amount after running 150,000 sheets is -2
There was almost no difference from the initial value of 0.1 μC / g. In a low humidity environment of 10 ° C and 15% RH and at 35 ° C and 90
Even under a high humidity environment of% RH, an image equivalent to normal humidity was obtained. The charge amount at 10 ° C. and 15% RH in the initial stage is −
It was 21.2 μC / g, and the charge amount at 35 ° C. and 90% RH was −20.4 μC / g, showing almost no difference. There was also no toner filming on the photoconductor.

Comparative Example 1 A toner was prepared and a developer was obtained in the same manner as in Example 2 except that E-89 manufactured by Orient Chemical Co., Ltd. was not used. Further, an image test was conducted by the same procedure.
When the charge amount was measured in the same manner as in Example 2, the charge amount at 10 ° C. and 15% RH in the initial stage was 23.5 μC / g, and the charge amount at 35 ° C. and 90% RH was 14.2 μC / g.
It was g, and the charge amount was decreased under high temperature and high humidity.

Comparative Example 2 A toner was prepared and a developer was obtained in the same manner as in Example 3, except that TP-302 manufactured by Hodogaya Chemical Co., Ltd. was not used. Further, an image test was conducted by the same procedure.
When the charge amount was measured in the same manner as in Example 1, the charge amount at 10 ° C. and 15% RH in the initial stage was −23.1 μC / g.
And the charge amount at 35 ° C. and 90% RH is −15.2 μm.
C / g, and the charge amount was reduced under high temperature and high humidity.

Comparative Example 3 A developer was obtained and an image test was conducted in the same manner as in Example 4 except that FCA-201-PB manufactured by Fujikura Kasei was not used. The charge amount at 10 ° C. and 15% RH in the initial stage is −19.3 μC / g, and the charge amount at 35 ° C. and 90% RH is −12.0 μC / g. It was falling.

[0049]

EFFECT OF THE INVENTION The toner for developing an electrostatic image according to the present invention is not charged by friction between toner particles, between toner and carrier, and toner in the case of one-component development and a charging member such as a developing sleeve or a blade. The toner is stable and has a triboelectric charge amount distribution that is sharp and uniform, has a good charge rising property, and can be controlled to a charge amount that is suitable for the developing system to be used. Very little change in charge amount. Furthermore,
With the developer using the toner, an image similar to the initial image can be obtained even when continuously used. In particular, when combined with a carrier having a silicone resin coating layer containing a conductive fine powder and a silane coupling agent, there is no background stain or toner scattering, and there is no deterioration in image quality due to edge phenomenon or charge accumulation phenomenon, Since the carrier coating layer does not peel off and the conductive fine powder does not separate even during continuous use, triboelectrification is stable, and a two-component developer that can obtain an image with high fidelity equivalent to the initial image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of an electrostatic image developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electrostatic latent image carrier 2 ... Toner conveying member 3 ... Elastic blade 4 ... Sponge roller 5 ... Stirring blade 6 ... Toner 7 ... Toner tank

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 9/08 333 9/10 352 361 (72) Inventor Kunihiko Tomita 1-chome Nakamagome, Ota-ku, Tokyo No. 3-6 In Ricoh Co., Ltd. (72) Inventor Hitoshi Ueda 1-3-6 Nakamagome, Ota-ku, Tokyo In Ricoh Co., Ltd.

Claims (3)

[Claims] 1. An electrostatic charge image developing toner comprising a binder resin, a colorant, and a charge control agent as a main component, wherein a charge control agent having a polarity opposite to that of the toner is used together. For toner. 2. The positive charging toner for electrostatic image development according to claim 1, wherein the binder resin is a polyester resin, an epoxy resin, or a polyol resin obtained by modifying an epoxy resin. 3. A two-component electrophotographic developer comprising the toner according to claim 1 or 2 and a carrier, wherein the carrier contains a conductive fine powder and a silane coupling agent. An electrophotographic developer having a layer.