JPH07114218A - Negative charge toner for electrostatic charge image developing - Google Patents

Abstract

PURPOSE:To obtain a toner showing stable triboelectrification property with negative polarity and having good dispersibility in a binder resin and excellent stability against environment by using a charge controlling agent comprising an iron-contg. azo dye having specified distribution of particle size including a component of fine particles. CONSTITUTION:This toner essentially consists of a binder resin, coloring agent and charge controlling agent. The charge controlling agent consists of an iron- contg. azo dye expressed by formula and is preliminarily controlled to have the distribution of grain size as described below measured by coal-tar method with 1.00-40.0mum measurement range using a 100mum aperture. The charge controlling agent contains a component of <=4.0mum particle size by <=75 number % and a component of >=16mum particle size by <=10wt.%, and has 5.0-9.0mum weight average particle size. In formula, X<1>, X<2> are hydrogen atoms, lower alkyl groups, m, m', n, n' are integers 1-3, R<1>, R<3> are hydrogen atoms or alkyl groups of 1-18 carbon number, R<2>, R<4> are hydrogen atoms or nitro groups, A<(+)> is a hydrogen ion, sodium ion, or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing toner used in electrophotography, electrostatic recording, electrostatic printing and the like, and more particularly to a developing toner excellent in negative charging property.

[0002]

2. Description of the Related Art Conventionally, a method of developing an electrostatic image with toner is roughly classified into a method using a so-called two-component developer in which a toner and a carrier are mixed and a method in which a carrier is not mixed. There is a method of using a one-component developer which is used by itself as a toner.

In the above method, the toner and the carrier are agitated and rubbed so that the toner and the carrier are charged to different polarities, and the electrostatically charged image having the opposite polarity is visualized by the charged toner. Depending on the type of carrier, there are a magnet brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method, and the like. The above-mentioned methods include a powder cloud method in which toner particles are sprayed, a contact development method in which toner particles are directly brought into contact with an electrostatic image surface (also referred to as touchdown development), and a magnetic conductive toner. There is an induction developing method in which the electrostatic charge image surface is brought into contact with.

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 a positive or negative charge depending on the polarity of the electrostatic image to be developed. In order to retain the electric charge in the toner, it is possible to utilize the triboelectric chargeability of the resin, which is one of the toner components, but in this method the toner chargeability is small, so the image obtained by development is easily fogged, It becomes unclear. Therefore, in order to impart a desired triboelectric chargeability to the toner, a dye that imparts a chargeability
It is common practice to add a pigment or a charge control agent.

For example, as the negative polarity charge control agent, a metal complex salt of monoazo dye, nitrohumic acid and its salt, salicylic acid, naphthoic acid or dicarboxylic acid of Co, Cr and F.
There are metal complexes such as e, sulfonated copper phthalocyanine pigments, nitro groups, halogen-introduced styrene oligomer chlorinated paraffins and melamine resins, but these have a complicated structure and their properties are not constant and their stability is poor. Also,
During thermal kneading, decomposition or mechanical shock, friction, changes in temperature / humidity conditions, etc. are likely to cause decomposition or deterioration, and a phenomenon in which charge controllability is deteriorated is likely to occur. Further, in some cases, the chargeability changes depending on the environment. Further, when the conventional toner containing these charge control agents is used for a long time, filming may occur on the photoconductor due to poor charging.

Further, considering the triboelectrification controllability and safety, JP-A-61-155463 and JP-A-61-155.
No. 464, JP-A-5-53375, and JP-A-5-533.
No. 76, JP-A-5-53377, etc., iron complexes are used as charge control agents, but these charge control agents are insoluble in the binder resin,
In addition, since the charge control agent particles are extremely likely to aggregate, it is extremely difficult to disperse the charge control agent uniformly in the toner binder, and the charge control agent particles are not uniformly dispersed in each toner particle. Therefore, problems such as fogging and toner scattering occur.

It is known that contamination of the carrier surface by the charge control agent particles detached from the toner surface causes a decrease in the charge amount of the developer, but such contamination of the carrier surface by the charge control agent is prevented. Therefore, by reducing the particle size of the charge control agent particles by mechanical pulverization and removing the coarse powder side component of the charge control agent particles by classification, it is possible to improve the dispersibility of the charge control agent in the binder resin, Although a method of hot-melt kneading a part of the binder resin has been adopted, the present situation is that a sufficient effect has not been obtained yet.

On the other hand, recently, due to the advantages such as the vinyl chloride mat fusion resistance of the toner, the storage stability and the low temperature fixing property being compatible with each other,
Polyester resins and epoxy resins are often used as binder resins. However, when a polyester resin or an epoxy resin is used as a binder resin in a toner, in any case, even if the charge amount is low or high, the charge amount decreases with repeated use, causing fog and toner scattering, etc. There was a problem that it was difficult. This is because the polyester resin and epoxy resin have a chemical structure of -COO.
This is probably because functional groups such as H and —OH groups remain, which hinders maintaining stable chargeability.

As a mechanism of development when a two-component developer is used, fine toner particles are held on the surface of a relatively large carrier particle by an electrostatic force generated by friction between the two particles, which is electrostatic. When approaching the latent image (electrostatic image), the attraction force in the latent image direction on the toner particles due to the electric field formed by the electrostatic latent image overcomes the binding force between the toner particles and the carrier particles, and the toner particles are It has been proposed that the electrostatic latent image is visualized by being attracted and attached onto the electrostatic latent image. 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 due to mechanical collision such as collision between particles or collision between the particles and a developing device, and further, a so-called spent toner is formed due to heat generated by these effects. Occurs, the chargeability of the carrier decreases with the lapse of use time, and eventually it becomes necessary to replace the entire developer.

In order to prevent such spent formation,
Conventionally, a method of coating various resins on the surface of a carrier has been proposed, but in reality, 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 also causes spent after repeated copying. 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, but since the silicone resin has low mechanical strength, it is used in a strong stirring or developing section such as a high speed copying machine. When the carrier particles collide with the inner wall of the developing section or the surface of the photoconductor or the particles collide with each other due to long-term stirring, the silicone resin coating layer is abraded / peeled over time, and triboelectrification causes toner and silicone resin. There is a problem that the charge amount of the developer cannot be kept constant and the image quality deteriorates because the relationship between the toner and the carrier core particles changes from the relationship between the toner and the carrier core particles.
Further, when the carrier core particles are coated with a silicone resin, the silicone resin itself has a high electric resistance. Therefore, when it is used as a two-component developer, there is a drawback that the image quality is deteriorated due to an edge phenomenon and a charge accumulation phenomenon. It was

The drawbacks of such a coated carrier can be ameliorated by dispersing a conductive substance in the coating layer. That is, when a certain degree of conductivity is given to the carrier, the carrier acts as a developing electrode, and the electrostatic latent image on the photosensitive member is developed in a state where the developing electrode and the surface of the photosensitive member are very close to each other. Needless to say, even if the black portion has a large area, the line portion is faithfully reproduced as the original.

Carbon, tin oxide, etc. have hitherto been used as such a conductive material. However, when such a conductive material is dispersed in the coating layer of the carrier, the following drawbacks are observed. That is, generally, the toner and the carrier are charged when they come into contact with 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 of the carrier due to the use over time, and the charge amount is changed. In order to solve this problem, JP-A-62-1
No. 82759 discloses an improvement by treating carbon with aminosilane, amino-modified silicone oil or the like, but there is a problem that cost increases due to increase in treatment steps.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances of the prior art, and its purpose is to charge a toner such as toner particles or toner and a carrier, a developing sleeve or a blade. To provide a toner that has stable triboelectrification with an imparting member, has a sharp and uniform triboelectrification amount distribution, has good charge rising property and environmental stability, and can control the electrification amount suitable for a developing system to be used. Another object is to provide a toner capable of obtaining an image of the same degree as the initial image even when continuously used.

[0016]

As a result of intensive studies, the inventors of the present invention have found that the fine powder side component of the charge control agent is involved in the contamination of the carrier surface by the charge control agent. It has been found that the above object can be achieved by a toner containing a charge control agent composed of an iron-containing azo dye having a specific particle size distribution containing components, and has completed the present invention.

That is, according to the present invention, a binder resin,
In the toner mainly composed of a colorant and a charge control agent,
3. The charge control agent is composed of an iron-containing azo dye represented by the following general formula 1, and has a particle size distribution of 100 μm, and a measurement area is 1.00 to 40.0 μm. It is adjusted in advance so that the component of 0 μm or less is 75% or less in number%, the component of 16 μm or more is 10% or less in weight% and the weight average diameter is in the range of 5.0 to 9.0 μm. A negatively chargeable toner for developing an electrostatic image is provided.

[Chemical 1]

Further, according to the present invention, a negative electrode for developing an electrostatic charge image is characterized in that it contains a fluorine-containing quaternary ammonium salt represented by the following general formula 2 as an auxiliary charge control agent together with the charge control agent. A chargeable toner is provided.

[Chemical 2] (In the formula, X, Y, R ^{5 to} R ⁶ , n and m each represent the following: X; —SO ₂ — or —CO—, R ⁵ , R ⁶ , R ⁷ and R ⁸ ;
Hydrogen atom, lower alkyl group or aryl group having 1 to 10 carbon atoms, Y; iodine atom or bromine atom, n; positive integer, m;
Positive integer. )

Generally, a toner for developing an electrostatic image is prepared by heat-melting and kneading a raw material composed of a binder resin, a colorant, a charge control agent and the like. However, since the charge control agent particles are very likely to aggregate, the binder resin is used. On the other hand, it is easy to disperse in the state of secondary and tertiary aggregation without dispersing in the state of primary particles. When a large number of the secondary and tertiary aggregates are present in the toner, the aggregates of the charge control agent present on the toner surface and in the vicinity of the surface are desorbed from the toner surface by mechanical impact force and promote the contamination of the carrier surface. Will result.

For the purpose of making the dispersion state of the charge control agent in the binder resin more uniform, the particle size of the charge control agent particles is reduced by mechanical pulverization and the coarse powder side component of the charge control agent particles is removed by classification. However, these methods result in an increase in the proportion of the charge control agent aggregates in the binder resin. In addition, a method of preliminarily homogenizing the dispersion state by melt-kneading a part of the charge control agent and the binder resin in advance is taken, but in this method also, the charge control agent aggregates in the binder resin are made into primary particles. It's not easy to do. Also, even if the charge control agent aggregate is successfully made into primary particles, the release of the charge control agent from the toner surface cannot be completely prevented. Since the surface area is large, it promotes contamination of the surface of the carrier and reduces the charge amount of the developer. This method is also known to significantly impair the fixing characteristics.

However, in the negatively chargeable toner for developing an electrostatic image according to the present invention, the compound represented by the general formula 1 is used as the charge control agent.
Since the iron-containing azo dye represented by the formula (1) was selected and the content of the fine powder side component in the charge control agent particles was adjusted to a specific range in advance, it was decided to use the one which is the coagulation of the charge control agent in the binder resin. The proportion of aggregates is reduced, and as a result, the contamination of the carrier surface by the charge control agent is reduced.

The use of the iron-containing azo dye represented by the general formula 1 in the toner for developing an electrostatic charge image is disclosed in the above-mentioned Japanese Patent Laid-Open No. 61-155464. Nothing is said about the particle size distribution of the iron-containing azo dye, and the publication does not suggest the effect of reducing carrier contamination according to the present invention. In addition, JP-A-62-5
4276, JP-A-63-202759, JP-A-3-
Japanese Patent No. 157670 proposes a toner in which a charge control agent having a regulated particle size is blended, but these documents also do not mention the fine powder side component of the charge control agent.

The negative charging toner for developing an electrostatic image of the present invention comprises the iron-containing azo dye represented by the general formula 1 as a charge control agent and has a particle size distribution of 100.
A measurement area of 1.00 to 40.
When measured by the Coulter method, which is 0 μm, 4.0
The number-% component is 75% or less by number%, the 16-μm component is 10% or less by weight, and the weight average diameter is 5.0 to 9.
It is preliminarily adjusted to be in the range of 0 μm.

60% to 7% by number of components having a thickness of 4.0 μm or less
When it is contained at a rate of 5%, the decrease in the amount of charge with time due to carrier contamination by the charge control agent reaches a practical level.
When the content of the component having a particle size of 4.0 μm or less is 40 to 60% in terms of number%, the saturated charge amount, the rising of the charge,
Environmental stability and reduction of charge amount with time are particularly good. Furthermore,
When the content of the component of 16 μm or more is 10% or less in weight% and the weight average diameter is in the range of 5.0 to 9.0 μm, the saturated charge amount, the rise of charge and the environmental stability are good. If the content of the component of 16 μm or more exceeds 10% by weight, or if the weight average diameter is 9.0 μm or more, initial characteristics such as saturated charge amount, rising of charge, and environmental stability are deteriorated.

As a method for adjusting the particle size distribution of the charge control agent, all known methods can be used, and the method is not limited to the examples described below. As a specific means, it can be adjusted by controlling reaction conditions such as temperature during crystallization, reaction time, solvent composition, and concentration, but a simpler method is to control the charge by a wind classifier. The method of removing the fine powder side component of an agent is mentioned.

Further, in the toner of the present invention, it is very preferable to contain the fluorine-containing quaternary ammonium salt represented by the general formula 2 as an auxiliary charge control agent in addition to the charge control agent. By containing the quaternary ammonium salt, a better triboelectric charging ability can be imparted.

When the toner of the present invention is used as a two-component developer, it is preferable to use a carrier having a silicone resin coating layer as a carrier to be mixed. In particular,
It is more desirable that the silicone resin coating layer of the carrier contains conductive fine powder, or conductive fine powder and a silane coupling agent. Further, the conductive fine powder is carbon black, and the silane cup More preferably, the ring agent is an aminosilane coupling agent. That is, it is possible to obtain a dry two-component type developer which is durable, does not deteriorate the image quality due to the edge effect and the phenomenon of charge accumulation, and exhibits stable triboelectric chargeability even when used over time.

The carrier obtained by coating the surface of the core particles with the silicone resin containing the conductive fine powder and the silane coupling agent has the 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 can be effectively suppressed. Particularly, an aminosilane coupling agent having a primary and / or secondary amino group is suitable for controlling the negative charge of the toner.

A typical example of the iron-containing azo dye represented by the general formula 1 used as a charge control agent in the toner of the present invention is Eisencolor T-77 manufactured by Hodogaya Chemical Co., Ltd. However, it is not limited to this. The amount 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 not uniquely limited. It is preferably used in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Particularly preferably, it is in the range of 2 to 5 parts by weight. If the amount is less than 1 part by weight, the negative charging of the toner is insufficient, which is not practical. On the contrary, if the amount is more than 10 parts by weight, the chargeability of the toner is too large and the electrostatic attraction force with the carrier increases. This causes a decrease in developer fluidity and a decrease in image density.

Typical examples of the fluorine-containing quaternary ammonium salt represented by the general formula 2 used as an auxiliary charge control agent together with the iron-containing azo dye represented by the general formula 1 are as follows. As shown in Table 1 below.

[0031]

[Table 1- (1)]

[0032]

[Table 1- (2)]

[0033]

[Table 1- (3)]

[0034]

[Table 1- (4)]

[0035]

[Table 1- (5)]

[0036]

[Table 1- (6)]

[0037]

[Table 1- (7)]

[0038]

[Table 1- (8)]

[0039]

[Table 1- (9)]

Examples of the binder resin used in the toner of the present invention include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene, and their substitution products; styrene / p-chlorostyrene copolymers and 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, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / vinyl methyl copolymer Styrene-based copolymers such as ketone copolymers, styrene / butadiene copolymers, styrene / isoprene copolymers, styrene / acrylonitrile / indene copolymers, styrene / maleic acid copolymers, styrene / maleic acid ester copolymers Combined; polymethylmethacrylate, polybutylmethacrylate, 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. These are used alone or as a mixture.

Further, as the binder resin particularly suitable for pressure fixing, for example, the following resins may be mentioned, which may be used alone or in a mixture. Polyolefins (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resins, polyester resins, styrene / butadiene copolymers (monomer ratio 5 to 30:95 to 70), olefin copolymers ( Ethylene / acrylic acid copolymer, ethylene /
Acrylic ester copolymer, ethylene / methacrylic acid copolymer, ethylene / methacrylic acid ester copolymer,
Ethylene / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, ionomer resin), polyvinylpyrrolidone resin, etc.

Among these, it is particularly preferable to use a polyester resin and an epoxy resin from the viewpoints of vinyl chloride mat fusion resistance, storage stability and low temperature fixability. The polyester resin in this case is obtained by polycondensation of alcohol and carboxylic acid, and specific examples of the alcohol and carboxylic acid include the following.

Alcohols; polyethylene glycol,
Diethylene glycol, triethylene glycol, 1,
Diols such as 2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol and 1,4-butene diol,
Etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropyleneized bisphenol A, which are saturated or unsaturated with 3 to 22 carbon atoms. Divalent alcohol units substituted with saturated hydrocarbon groups, other divalent alcohol units, sorbitol, 1, 2, 3,
6-hexanetetrol, 1,4-salbitan, pentaesthritol, dipentaesthritol, tripentaesthritol, sucrose, 1,2,4-butanetriol, 1,
Trivalent of 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. The above polyhydric alcohol monomers and the like.

Carboxylic acids; palmitic acid, stearic acid, monocarboxylic acids such as oleic acid, 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 organic acid monomers in which they are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, anhydrides of these acids, dimers of lower alkyl esters and linoleic acid Body, other divalent organic 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-Butantcarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-
Trivalent or higher polyvalent carboxylic acid monomers such as methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer acid, and anhydrides of these acids.

The epoxy resin is, for example, a polycondensate of bisphenol A and epichlorohydrin,
For example, Epomic R362, R364, R365, R
366, R367, R369 (above, manufactured by Mitsui Petrochemical Co., Ltd.), Epotote YD-011, YD-012, Y
D-014, YD-904, YD-017, (all manufactured by Tohto Kasei Co., Ltd.), Epicoat 1002, 1004, 100
7 (above, manufactured by Shell Chemical Co., Ltd.) and the like are commercially available.

The colorants used in the toner of the present invention include carbon black, lamp black, iron black, ultramarine blue,
Nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, hansa yellow G, rhodamine 6G, lake, chalco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl methane dyes, monoazo dyes and disazo dyes, etc. Any conventionally known dye or pigment may be used alone or in combination.

The toner of the present invention may further contain a magnetic material and be used as a magnetic toner. The magnetic materials contained in the magnetic toner include magnetite, hematite,
Metals such as iron oxides such as ferrite, iron, cobalt, nickel, or aluminum, cobalt, etc. of these metals
Examples thereof include alloys of metals such as copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof. It is desirable that these ferromagnetic materials have an average particle size of about 0.1 to 2 μm.
It is about 20 to 200 parts by weight with respect to 00 parts by weight, and particularly preferably 40 to 150 parts by weight with respect to 100 parts by weight of the resin component.

Additives may be added to the toner of the present invention as required. Examples of the additive include a lubricant such as tetrafluoroethylene resin and zinc stearate, or an abrasive such as cerium oxide and silicon carbide, or a fluidity-imparting agent such as colloidal silica and aluminum oxide, an anti-caking agent, or carbon. There are conductivity imparting agents such as black and tin oxide, and fixing aids such as low molecular weight polyolefin.

When the toner of the present invention is used as a two-component developer, it is used as a mixture with carrier powder. As the carrier that can be used in the present invention, all known carriers can be used, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads and the like, and the surface thereof is treated with a resin or the like. The ones that were In particular, the desirable carrier in the present invention is, as described above, carrier core particles (average particle diameter of 10 to 1000).
μm, preferably 30 to 500 μm) is a type whose surface is coated with a silicone resin, and the amount of the silicone resin used is 1 to 10 with respect to the carrier core particles.
% By weight.

The silicone resin in this case may be any conventionally known silicone resin, for example, commercially available KR manufactured by Shin-Etsu Silicone Co., Ltd.
261, KR271, KR272, KR275, KR2
80, KR282, KR285, KR251, KR15
5, KR220, KR201, KR204, KR20
5, KR206, SA-4, ES1001, ES100
1N, ES1002T, KR3093 and Toray Dow Corning Silicone SR2100, SR2101, S
R2107, SR2110, SR2108, SR210
9, SR2115, SR2400, SR2410, SR
2411, 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.

The coating layer composition is preferably prepared by adding conductive fine powder and a silane coupling agent to a silicone resin solution and dispersing them with an appropriate mixer. The conductive fine powder dispersed in the coating layer preferably has a particle size of about 0.01 to 5.0 μm, and is preferably added in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of the silicone resin. Furthermore, 0.1 to 20 parts by weight is preferable. As the conductive fine powder, conventionally known carbon black may be used, and in addition, contact black, furnace black and thermal black may be mentioned.

The silane coupling agent is a compound represented by the formula X ³ —Si (OR ⁹ ) ₃ , where X ³ is a functional group that reacts with an organic substance, and R ⁹ is a hydrolyzable group. is there. In particular, an aminosilane coupling agent having an amino group is desirable, and the amount is 0.1% with respect to 100 parts by weight of silicone resin.
It is preferable to add 1 to 10 parts by weight, preferably 0.2 to 5 parts by weight. Examples of the aminosilane coupling agent include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-anilinopropyltrimethoxysilane, octadecyldimethyl [3-
(Trimethoxysilyl) propyl] ammonium chloride and the like.

[0053]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. All parts shown below are based on weight.

(Adjustment of Particle Size Distribution of Charge Control Agent) Iron-containing azo dye, manufactured by Hodogaya Chemical Co., Ltd., Anzen Color T-77 having a particle size distribution of 100 μm is measured by a Coulter Multisizer having a measurement area of 1.00 to 40. When measured in the range of 0.0 μm, the number of components of 4.0 μm or less is 86.4% by number%, the amount of components of 16 μm or more is 5.8% by weight,
The number average diameter was 3.0 μm and the weight average diameter was 4.5 μm.

Charge Control Agent A Anzen Color T-77 manufactured by Hodogaya Chemical Co., Ltd. is used as 100
When fine powder classification was performed with an MZR classifier, components of 4.0 μm or less were 75.8% in number%, components of 16 μm or more were 5.9% in weight%, number average diameter was 3.3 μm, weight average diameter. A charge control agent A having a particle size of 5.3 μm was obtained.

Charge Control Agent B Similarly, Anzen Color T-77 was subjected to fine powder classification with a 100MZR classifier to obtain a charge control agent B having a particle size distribution shown in Table 2.

Charge control agent C Anzen color T-77 (50 g) was added to 120 g of ethylene glycol, heated to 100 ° C., sufficiently dissolved, and then allowed to cool to room temperature, and precipitated crystals were separated by filtration and washed. Then, it was dried under reduced pressure at 50 to 60 ° C. to obtain a blackish brown fine powder. The particle size distribution of this black-brown fine powder was measured by a Coulter counter to find that the number of components of 4.0 μm or less was 45.7% by number%, and that of 16 μm or more was 8.9% by weight,
The number average diameter was 3.9 μm and the weight average diameter was 7.7 μm. This black-brown fine powder is used as a charge control agent C.

Charge Control Agent D Anzen Color T-77 was subjected to coarse powder classification using a 100MZR classifier, and the charge control agent D having a particle size distribution shown in Table 2 was obtained.
Got

Charge Control Agent E Anzen Color T-77 was pulverized with a jet mill to obtain a charge control agent E having a particle size distribution shown in Table 2.

Charge Control Agent F Anzen Color T-77 was subjected to fine powder classification using a 100MZR classifier, and the charge control agent F having a particle size distribution shown in Table 2 was obtained.
Got

[0061]

[Table 2]

(Production of Carrier) Next, an example of production of a carrier having several silicone resins in the coating layer will be described.
These can be performed by known means.

Carrier Production Example 1 Composition of coating layer forming liquid Silicone resin (KR206: manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts Carbon black (# 44: manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) 3 parts Disperse the above formulation with a homomixer for 30 minutes. A coating layer forming liquid was prepared. This coating layer forming liquid was used to obtain an average particle size of 100
The surface of 1000 parts of spherical ferrite having a diameter of μm was coated with a fluidized bed coating device to obtain a carrier A having a coating layer formed thereon.

Carrier Production Examples 2 to 5 The following components and 100 parts of toluene were mixed and dispersed with a homomixer for 30 minutes to prepare a coating layer forming liquid.

Production Example 2 Silicone resin (SR2400: manufactured by Toray Dow Corning Silicone) 100 parts Tin oxide (S-1: manufactured by Mitsubishi Metals) 2 parts

Production Example 3 Silicone resin (SR2400: manufactured by Toray Dow Corning Silicone) 100 parts Carbon black (Ketjen Black: manufactured by Lion Akzo) 1.5 parts γ-anilinopropyltrimethoxysilane (SZ6083: Toray Dow Corning) Silicone) 0.3 part

Production Example 4 Silicone resin (KR206: manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts Carbon black (# 3600: manufactured by Mitsubishi Kasei Co., Ltd.) 1 part γ- (2-aminoethyl) aminopropyltrimethoxysilane (SH6020: Toray Dow) Corning Silicone) 0.1 part

Production Example 5 Silicone resin (KR206: manufactured by Shin-Etsu Silicone Co., Ltd.) 100 parts Carbon black (# 44: manufactured by Mitsubishi Kasei Co., Ltd.) 1.5 parts γ- (2-aminoethyl) aminopropylmethyldimethoxysilane (SH6020: Toray Dow Corning Silicone) 0.4 part

This coating layer forming liquid was applied to the surface of 1000 parts of spherical ferrite having an average particle diameter of 70 μm by using a fluidized bed type coating device to form a coating layer on carriers B, C,
D and E were obtained.

Example 1 Styrene / 2-ethylhexyl acrylate copolymer 100 parts Carbon black 10 parts Charge control agent A 2 parts

The mixture having the above composition was thoroughly stirred and mixed in a Henschel mixer, and then 130 to 140 ° C. with a roll mill.
After heating and melting for about 30 minutes at room temperature and cooling to room temperature, the resulting kneaded product was pulverized and classified to obtain a toner having a particle size of 5 to 20 μm. 97.5 parts of iron powder carrier of 100 to 250 mesh was mixed with 2.5 parts of this toner by a ball mill to obtain a developer.

Next, the developer was set in a plain paper copying machine (FT7570) manufactured by Ricoh Co., Ltd., and development was carried out. 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 −20.1 μC /
The charge amount of the toner after running 80,000 sheets was −17.1 μC / g, which was almost the same. Also,
35 ° C, 90% RH high humidity environment, 10 ° C, 1
An image equivalent to normal humidity was obtained even in a low humidity environment of 5% RH. Further, there was no toner filming on the photoconductor.

Comparative Example 1 A developer was obtained in the same manner as in Example 1 except that the charge control agent A was replaced by Anzen Color T-77 manufactured by Hodogaya Chemical Co., Ltd., and an image test was conducted. Was done. As the initial image, a clear image without fog was obtained, but from about 20,000 sheets, an unclear image with fog was formed, and toner filming was observed on the surface of the photoconductor. Also,
When an image test was performed in a high humidity environment of 35 ° C. and 90% RH, the image density was as low as 0.85, and an unclear image with fog was obtained. When the charge amount was measured in the same manner as in Example 1, the initial charge amount was -18.4 μC / g.
However, it decreased to −7.7 μC / g after 20,000 sheets. The transition of the charge amount of the developer in Example 1 and Comparative Example 1 is shown in FIG.

Example 2 A toner and a developer were prepared in the same manner as in Example 1 except that the carrier C was used, and a similar image forming test was conducted. As a result, a good image was obtained, and the image was obtained. It did not change after 100,000 images were printed. Moreover, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was -2.
It was 3.8 μC / g, and the charge amount of the toner after running 100,000 sheets was −18.7 μC / g, which was almost the same as the initial value. Further, there was no toner filming on the photoconductor.

Example 3 Epoxy resin (R365: manufactured by Mitsui Petrochemical Co., Ltd.) 80 parts Epoxy resin (YD-017: manufactured by Toto Kasei Co., Ltd.) 20 parts Carbon black 10 parts Charge control agent A 2 parts

The mixture having the above composition was melt-kneaded, cooled, pulverized and classified in the same manner as in Example 1 to obtain a toner having a particle diameter of 5 to 25 μm. 2.5 parts of this toner was mixed with 97.5 parts of carrier A coated with a silicone resin in a ball mill to obtain a developer.

Next, the developer was set in the copying machine (FT7570) used in Example 1 and an image test was conducted. As with Example 1, a good image with high sharpness was obtained. The image remained the same even after 100,000 images were printed. Furthermore, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −22.1 μC / g.
The toner charge amount after running 10,000 sheets is -17.3.
There was almost no difference between μC / g and the initial value. Also, 35
℃, 90% RH high humidity environment, 10 ℃, 15%
Even under a low humidity environment of RH, an image equivalent to normal humidity was obtained. Further, there was no toner filming on the photoconductor.

Example 4 Epoxy resin (R365: manufactured by Mitsui Petrochemical Co., Ltd.) 80 parts Epoxy resin (YD-017: manufactured by Toto Kasei Co., Ltd.) 20 parts Carbon black 10 parts Charge control agent A 2 parts Exemplified compound 2 1 part

The raw material mixture having the above composition was melt-kneaded, cooled, pulverized and classified in the same manner as in Example 1 to obtain a toner having a particle diameter of 5 to 25 μm. 2.5 parts of this toner was mixed with 97.5 parts of carrier B coated with a silicone resin in a ball mill to obtain a developer.

Next, the developer was set in the copying machine (FT7570) used in Example 1 and an image test was conducted. As with Example 1, a good image with high sharpness was obtained. The image remained the same even after 100,000 images were printed. Furthermore, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −22.1 μC / g.
The toner charge amount after running 10,000 sheets is -17.3.
There was almost no difference between μC / g and the initial value. Also, 35
℃, 90% RH high humidity environment, 10 ℃, 15%
Even under a low humidity environment of RH, an image equivalent to normal humidity was obtained. Further, there was no toner filming on the photoconductor.

Example 5 Epoxy resin (R365: manufactured by Mitsui Petrochemical Co., Ltd.) 80 parts Epoxy resin (YD-017: manufactured by Toto Kasei Co., Ltd.) 20 parts Carbon black 8 parts Charge control agent B 3 parts Exemplified compound 1 2 parts

The mixture having the above composition was thoroughly stirred and mixed in a Henschel mixer in the same manner as in Example 1, and then heat-melted with a roll mill at a temperature of 130 to 140 ° C. for about 30 minutes,
After cooling to room temperature, the obtained kneaded product is pulverized and classified to 5-2.
A toner having a particle size of 0 μm was obtained. To 100 parts of this toner, 3 parts of silicon carbide (particle size: about 2 μm) and 0.1 part of hydrophobic colloidal silica were sufficiently stirred and mixed with a speed kneader to obtain a toner.

When this toner was loaded into a developing device as shown in FIG. 2 and continuous copying was carried out and an image test was conducted, a good image was obtained. The image did not change after 40,000 images were printed.

This developing method will be explained. As shown in the drawing, the toner 6 contained in the toner tank 7 is forcibly drawn to the sponge roller 4 by the stirring blade 5, and the toner 6 is supplied to the sponge roller 4. . Then, 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 direction of the arrow, and is rubbed and electrostatically or physically adsorbed, so that the toner conveying member 2 is moved in the arrow direction. It strongly rotates in the direction, and a uniform thin toner layer is formed by the elastic blade 3 and is triboelectrically charged. After that, the toner is conveyed to the surface of the electrostatic latent image carrier 1 that is in contact with or in the vicinity of the toner conveying member 2, and the latent image is developed. The electrostatic latent image is exposed by exposing the organic photoconductor to a negative DC charge of 800 V, then forms a latent image and is subjected to reversal development.

Further, in order to measure the specific charge amount Q / M of the toner on the toner carrying member, the toner on the toner carrying member is sucked through a Faraday cage equipped with a filter layer on the outlet side, and the Faraday gauge is used. When the Q / M was measured by a suction method specific charge amount measuring device for measuring the specific charge of the toner trapped inside, it was confirmed that the toner was sufficiently charged with −9.7 μC / g. Also, the toner charge amount after running 40,000 sheets is -7.8 μC / g.
There was almost no difference from the initial value. Further, even under high humidity and low humidity, image quality equivalent to normal humidity was obtained. Also, there was no toner filming on the photoconductor.

Example 6 Polyester resin (Luna Pale 1447: Arakawa Chemical Co., Ltd.) 100 parts Polypropylene 5 parts Carbon black 10 parts Charge control agent B 3 parts Exemplified compound 3 0.5 parts Metal-containing monoazo dye 1 part

The mixture having the above composition was melt-kneaded, cooled, pulverized and classified in the same manner as in Example 1 to obtain a toner having a particle diameter of 5 to 25 μm. 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, the developer was set in the copying machine (FT7570) used in Example 1 and an image test was conducted. As with Example 1, a good image with high fidelity was obtained. The image did not change even after 120,000 images were printed. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −25.4 μC / g.
The toner charge amount after running 10,000 sheets is -19.4.
There was almost no difference between μC / g and the initial value. Also, 35
℃, 90% RH high humidity environment, 10 ℃, 15%
Even under a low humidity environment of RH, an image equivalent to normal humidity was obtained. Further, there was no toner filming on the photoconductor.

Example 7 Polyester Resin (Luna Pale 1447: Arakawa Chemical Co., Ltd.) 100 parts Candelilla Wax 102 (manufactured by Noda Wax Co., Ltd.) 5 parts Carbon Black 10 parts Charge Control Agent C 3 parts Exemplified Compound 3 0.5 parts

The raw material mixture having the above composition was melt-kneaded, cooled, pulverized and classified in the same manner as in Example 1 to obtain a toner having a particle diameter of 5 to 25 μm. 2.5 parts of this toner was mixed with 97.5 parts by weight of Carrier E coated with a silicone resin in a ball mill to obtain a developer.

Next, the developer was set in the copying machine (FT7570) used in Example 1 and an image test was conducted. As with Example 1, a good image with high fidelity was obtained. The image did not change even after 120,000 images were printed. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −26.1 μC / g.
The toner charge amount after running 10,000 sheets is -20.6
There was almost no difference between μC / g and the initial value. Also, 35
℃, 90% RH high humidity environment, 10 ℃, 15%
Even under a low humidity environment of RH, an image equivalent to normal humidity was obtained. Further, there was no toner filming on the photoconductor.

Comparative Example 2 A developer was obtained and an image test was conducted in the same manner as in Example 3 except that the charge control agent D was used in place of the charge control agent A in Example 3. As the initial image, a clear image without fog was obtained, but from about 10,000 sheets, an unclear image with fog was seen, and toner filming was observed on the surface of the photoconductor. When an image test was performed in a high humidity environment of 35 ° C. and 90% RH, the image density was as low as 0.80, and an unclear image with fog was obtained. When the toner charge amount was measured in the same manner as in Example 3, the initial charge amount was -18.8 μC / g, but after 10,000 sheets, it was -7.9.
It was as low as μC / g.

Comparative Example 3 A developer was obtained and an image test was conducted in the same manner as in Example 6 except that the charge control agent E was used in place of the charge control agent B in Example 6. As the initial image, a clear image without fog was obtained, but from about 10,000 sheets, an unclear image with fog was seen, and toner filming was observed on the surface of the photoconductor. Further, when an image test was carried out in a high humidity environment of 35 ° C. and 90% RH, the image density was as low as 0.78, and an unclear image with fog was obtained. When the toner charge amount was measured in the same manner as in Example 6, the initial charge amount was -17.1 μC / g, but after 10,000 sheets,
It was as low as −6.9 μC / g.

Comparative Example 4 A developer was obtained and an image test was conducted in the same manner as in Example 7 except that the charge control agent F was used in place of the charge control agent C in Example 7. The initial image was a poor image with a slight fog, and after about 20,000 sheets, the fog increased and became an unclear image. Further, when an image test was carried out in a high humidity environment of 35 ° C. and 90% RH, the image density was as low as 0.92 and fog occurred. When the toner charge amount was measured in the same manner as in Example 7, the initial charge amount was −
Low at 11.5μC / g, -6.5μ after 20,000 sheets.
It was as low as C / g.

[0095]

The negatively chargeable toner for developing an electrostatic image according to claim 1 uses a charge control agent composed of an iron-containing azo dye having a specific particle size distribution containing a fine powder side component, and thus has a stable negative polarity. It exhibits triboelectrification properties, has good dispersibility in a binder resin, and has excellent environmental stability. Therefore, according to the present toner, an image having the same quality as the initial image can be obtained even after continuous copying.

Since the negatively chargeable toner for developing an electrostatic charge image according to claim 2 further contains a specific fluorine-containing quaternary ammonium salt as an auxiliary charge control agent, an effect of imparting better triboelectric charging ability is obtained. Is added.

Since the negatively chargeable toner for developing an electrostatic image according to claim 3 uses a polyester resin or an epoxy resin as a binder resin, it is said that the PVC mat fusion resistance, the storage stability and the low temperature fixability are compatible with each other. The effect is added.

[Brief description of drawings]

FIG. 1 is a graph showing changes in the charge amount of a developer in Example 1 and Comparative Example 1.

FIG. 2 is a schematic view of a developing device used in Example 5.

[Explanation 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 351

Claims (3)

[Claims] 1. A toner containing a binder resin, a colorant and a charge control agent as a main component, wherein the charge control agent is composed of an iron-containing azo dye represented by the following general formula 1 and has an aperture with a particle size distribution of 100 μm. In the measurement by the Coulter method in which the measurement area is 1.00 to 40.0 μm, the component of 4.0 μm or less is 75% or less by number%, the component of 16 μm or more is 10% or less by weight%, and the weight average diameter is A negatively chargeable toner for developing an electrostatic charge image, which has been adjusted in advance to a range of 5.0 to 9.0 μm. [Chemical 1] 2. The electrostatic charge image developing device according to claim 1, wherein the fluorine-containing quaternary ammonium salt represented by the following general formula 2 is contained as an auxiliary charge control agent together with the charge control agent. Negative charging toner. [Chemical 2] (In the formula, X, Y, R ^{5 to} R ⁶ , n and m each represent the following: X; —SO ₂ — or —CO—, R ⁵ , R ⁶ , R ⁷ and R ⁸ ; hydrogen atom , A lower alkyl group or aryl group having 1 to 10 carbon atoms, Y: iodine atom or bromine atom, n; positive integer, m; positive integer.) 3. The negatively chargeable toner for electrostatic image development according to claim 1, wherein the binder resin is a polyester resin or an epoxy resin.