JP3409102B2 - Toner for developing electrostatic images - Google Patents

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 image and a two-component developer used in electrophotography, electrostatic printing, etc., and more particularly to a toner developer for negatively chargeable development.

[0002]

2. Description of the Related Art Conventionally, a method of developing an electrostatic charge image using a toner as disclosed in JP-A-61-147261 is roughly classified into a so-called two-component system in which a toner and a carrier are mixed. There are a method of using a developer and a method of using a one-component developer which is used alone as a toner without being mixed with a carrier.

In the above method, the toner and the carrier are agitated and rubbed so that the toner and the carrier are charged with different polarities, and an electrostatic charge image having an opposite polarity is visualized by the charged toner. Depending on the type, 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 a contact developing method in which toner particles are directly brought into contact with an electrostatic latent image surface for development (both touch-down development). U), a dielectric 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 natural resin or synthetic resin is used. For example, particles in which a colorant is dispersed in a binder resin such as polystyrene are finely pulverized to have a particle size of about 1 to 30 μm and 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. It is possible to utilize the triboelectric chargeability of the resin which is a component of the toner, but in this method the toner chargeability is low, so the image obtained by development is easily fogged,
It becomes unclear. Therefore, in order to impart a desired triboelectric charging property to the toner, a dye, a pigment or a charge control agent which imparts the charging property 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.
There are metal complexes of i, Cr, Zn, etc., sulfonated copper phthalocyanine pigments, nitro groups, halogen-incorporated styrene oligomers, chlorinated paraffins, melamine resins, etc., but these dyes have complicated structures and constant properties. No, the 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. In addition, the charging property often changes depending on the environment. Furthermore, when a conventional toner containing the charge control agent is used for a long time, filming may occur on the photoconductor due to poor charging. Further, these metal complexes include Co, Ni, Cr and Z.
It contains heavy metals such as n and Cu that may cause environmental problems, and is not preferable for safety reasons.

Further, since these charge control agents are insoluble in the binder resin, they are known to separate from the toner surface by mechanical impact and contaminate the carrier surface, resulting in a decrease in the charge amount of the developer. There is. To prevent the carrier surface from being contaminated by such a charge control agent,
By reducing the particle size of the charge control agent particles by mechanical pulverization, it is possible to improve the dispersibility of the charge control agent in the binder resin, or to heat melt knead a part of the charge control agent and the binder resin in advance. However, the present situation is that the sufficient effect has not been obtained yet.

In consideration of the triboelectrification control agent and safety, JP-A-61-155463 and JP-A-60-155463 are used.
Japanese Patent Application Laid-Open No. 5-53375 and Japanese Patent Application Laid-Open No. 5-53376.
The iron complex described in JP-A-5-53377 is used as a charge control agent.
Since the solubility in the binder resin is low, it is extremely difficult to disperse the charge control agent uniformly in the toner binder, and the charge control agent is not evenly dispersed in each toner particle. However, problems such as toner scattering occur. Further, during continuous use, the charge amount of the developer is likely to decrease due to carrier contamination.

As a charge control agent having good compatibility with a binder resin, there is a charge control agent composed of a sulfonic acid group-containing resin, which is found in JP-A-63-184762. However, although the charge control agent is not released, the dispersibility in the binder resin is too good and a sufficient charge amount cannot be obtained. If the amount of the charge control agent used is increased in order to obtain a sufficient amount of charge, the fixability will be poor.

Further, 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 the polyester resin and the epoxy resin have functional groups such as —COOH and —OH groups remaining due to their chemical structure, which hinders maintaining stable chargeability.

Conventionally, as a mechanism of a two-component dry developer, fine toner particles are formed on the surface of a relatively large particle.
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 with a desired polarity and a sufficient charge amount during long-term use. . However, in the conventional developer, a toner film is formed on the carrier surface due to a collision between particles, a mechanical collision such as a collision between a particle and a developing machine, or heat generated by these actions, so-called spent formation occurs, and a carrier is generated. The charging characteristics of No. 1 deteriorate with the use time, and it becomes necessary to replace the entire developer. In order to prevent such a spent state, a method of coating the surface of a carrier with various resins has been proposed, but a satisfactory method has not been obtained yet. For example, styrene-methacrylate copolymer,
A carrier coated with a resin such as a styrene polymer has excellent charging characteristics, but has a relatively high surface critical surface tension,
The life as a developer was not so long because the spent was formed again during repeated copying. 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, strong stirring such as in a high speed copying machine,
If the carrier particles collide with the inner wall of the developing unit or the surface of the photoconductor, or if the particles collide with each other due to long-term stirring in the developing unit, the silicone resin coating layer will be abraded over time.
When the toner is peeled off and the frictional charge changes from the charge between the toner and the silicone resin to the charge between the toner and the carrier core particles, there is a problem that the charge amount of the developer cannot be kept constant and the image quality deteriorates. It was 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 improved to some extent 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 development is performed in a state where the developing electrode and the surface of the photoconductor to be developed are in close contact with each other. Even the black part of the area is faithfully reproduced as the original.

Carbon, tin oxide, etc. have hitherto 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. That is, generally, the toner and the carrier are charged by the contact between them. 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, in JP-A-62-182759, improvement is made 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. there were.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent triboelectric charging between toner particles or between toner and carrier, and toner in the case of one-component development and a charging agent such as a developing sleeve or a blade. It is stable, has a sharp and uniform triboelectric charge distribution, has good charge rising properties and environmental stability, and can be controlled to a charge amount suitable for the developing system used. It is to provide a toner that can obtain Furthermore, other purposes are that there is no background stain and toner scattering, there is no deterioration of image quality due to edge phenomenon and charge accumulation phenomenon, and there is no peeling of the carrier coating layer or separation of conductive fine powder even during continuous use. It is an object of the present invention to provide a two-component type developer which is stable in triboelectric charging and can obtain an image having high fidelity equivalent to that of an initial image.

[0015]

[Charge control agent (a)]

[Chemical 1] [Charge Control Agent (b)] Copolymer of Styrene / Acrylic Monomer and Sulfonic Acid-Containing Acrylamide Monomer Further, according to the present invention, there is provided the above toner in which the binder resin is a polyester resin. Further, in the two-component developer comprising the toner and the carrier, the carrier has a silicon resin coating layer, and the coating layer contains conductive fine powder and a silane coupling agent. A developer is provided.

[0016]

DETAILED DESCRIPTION OF THE INVENTION According to the studies by the present inventors, not only the charge control agent (a) alone cannot obtain a sufficient saturated charge amount, but also the carrier by the charge control agent (a) can be improved over time. Contamination is severe and cannot be used. On the other hand, with the charge control agent (b) alone, a sufficient saturated charge amount can be easily obtained and contamination by the charge control agent can be avoided, but the charge rising property is insufficient. Therefore, it has been found that fogging often occurs during continuous copying. Even if the prescription amount of the charge control agent (a) is increased, the abundance ratio of the charge control agent (a) on the toner surface per 1 g of the toner is 20 ×.
When it exceeds 10 ⁻³ (g / g), the saturated charge amount does not increase,
It has also been found that it is difficult to obtain a satisfactory toner in fact, since it only promotes contamination by the side effect of carrier. As a result of further diligent studies on this point, the present inventors have used the charge control agents (a) and (b) together, and found that the abundance ratio of the charge control agent (a) on the toner surface is 7 × 10 ^−3. It was found that an effective result can be obtained when it is set to -20 × 10 ^-3 (g / g).

When the abundance ratio of the charge control agent (a) on the toner surface is less than 7 × 10 ⁻³ (g / g), sufficient charge rising property is obtained as in the case of using the charge control agent (b) alone. Therefore, it is meaningless to use the charge control agents (a) and (b) together. Moreover, when it exceeds 20 × 10 ⁻³ (g / g),
Carrier contamination by the charge control agent is so great that the intended purpose of the present invention cannot be achieved.

Further, by using the above-mentioned two kinds of charge control agents of the present invention in combination, even if the binder resin is a polyester resin or an epoxy resin, good charging characteristics are obtained, and it is optimum as a negative charge control agent for low temperature fixing toner. You can get something.

In particular, the silicon resin coating layer of the carrier contains conductive fine powder and a silane coupling agent,
Since the conductive fine powder is carbon black and the silane coupling agent is an aminosilane coupling agent, it has durability and does not deteriorate in image quality due to an edge phenomenon or a charge accumulation phenomenon, and is stable even when used over time. A two-component developer for electrophotography exhibiting the above triboelectric charging property can be obtained.

Further, according to the present invention, by coating the surface of the core particles with the silicone resin containing the conductive fine powder and the silane coupling agent, the advantages of the conventional silicone resin coated carrier can be maintained. By imparting conductivity to the carrier, the phenomenon of charge accumulation in the carrier, the peeling of the coating layer, and the detachment of the conductive fine powder are effectively suppressed. Particularly, an aminosilane coupling agent having a primary and / or secondary amino group is preferable from the viewpoint of negative charge controllability of the toner.

The amount of the charge control agent used in the present invention as the charge control agent according to claim 1 is such that the type of binder resin, the presence or absence of additives used if necessary, and the toner production method including the dispersion method. The charge control agent (a) is determined by the method and is not limited to any specific value.
Used in the range of up to 3 parts by weight. The preferred range is 1 to 2 parts by weight. If it is less than 0.5 part by weight, the charge rising property is insufficient and it is not practical. On the other hand, if the amount exceeds 10 parts by weight, the chargeability of the toner is too large, which leads to a decrease in the fluidity of the developer and a decrease in the image density. In addition, the charge control agent (b)
Is 0.1-10 with respect to 100 parts by weight of the binder resin.
Used in the range of parts by weight. The preferred range is 3 to 5 parts by weight. If the amount is less than 0.1 parts by weight, the charge rising property is insufficient, which is not practical. On the other hand, when the amount exceeds 10 parts by weight, the chargeability of the toner is too large, 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.

Specific examples of the charge control agents (a) and (b) used in the present invention are shown below, but the present invention is not limited thereto.

[0023]

[Table 1- (1)]

[0024]

[Table 1- (2)]

[0025] [Charge control agent (b)]   (Exemplified compound b-1)     Styrene 95 parts by weight     2-acrylamido-2-methylpropanesulfonic acid 5 parts by weight   Copolymer composed of the above and having a weight average molecular weight of 8,000 (hereinafter the same)   (Exemplified compound b-2)     90 parts by weight of styrene     2-acrylamido-2-methylpropanesulfonic acid 10 parts by weight     (Weight average molecular weight 8,000)   (Exemplified compound b-3)     90 parts by weight of styrene     2-acrylamido-2-methylpropanesulfonic acid 10 parts by weight     (Weight average molecular weight 6,000)   (Exemplified compound b-4)     Styrene 97 parts by weight     2-acrylamido-2-methylpropanesulfonic acid 3 parts by weight     (Weight average molecular weight 10,000)   (Exemplified Compound b-5)     90 parts by weight of styrene     BA (butyl acrylate) 5 parts by weight     2-acrylamido-2-methylpropanesulfonic acid 5 parts by weight     (Weight average molecular weight 8,000)   (Exemplified compound b-6)     90 parts by weight of styrene     5 parts by weight of t-BMA (t-butyl methacrylate)     2-acrylamido-2-methylpropanesulfonic acid 5 parts by weight     (Weight average molecular weight 7,500)

As the binder resin used in the present invention, a unitary combination of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, and its substitution product;
Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer Coalesced, styrene-
Styrene-based copolymers such as 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 resins, aromatic petroleum resins, chlorinated paraffin, paraffin wax and the like,
They can be used alone or as a mixture.

Further, as the binder resin particularly suitable for pressure fixing, the following can be used alone or in combination. Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, oxidized polyethylene polytetrafluoroethylene, etc.), epoxy resin, polyester resin, styrene-butadiene copolymer (monomer ratio 5 to 30:95 to 7)
0), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl chloride copolymer, Examples thereof include ethylene-vinyl acetate copolymers, ionomer resins) and polyvinylpyrrolidone resins. Further, particularly, the polyester resin used in the present invention includes those obtained by polycondensation of an alcohol component and a carboxylic acid component. As the alcohol component, polyethylene glycol, diethylene glycol, triethylene glycol-
1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, 1,4-butenediol and other diols, 1,4- (bishydroxymethyl) cyclohexane, bisphenol A, Etherified bisphenols such as hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropyleneized bisphenol A, etc., and dihydric alcohol units obtained by substituting these with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms. , Other dihydric alcohol units, sorbitol, 1, 2,
3,6-hexanetetrol, 1,4-salbitan, pentaesthritol, dipentaesthritol, tripentaesthritol, sucrose, 1,2,4-butanetriol,
1,2,5-pentanetriol, glycerol, 2-
Methyl propanetriol, 1-methyl-1,2,4-
Examples thereof include trihydric or higher polyhydric alcohol monomers such as butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Further, as the carboxylic acid component, for example, palmitic acid, stearic acid, monocarboxylic acids such as oleic acid, maleic acid, fumaric acid, mesaconic acid, citracohexanedicarboxylic 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 obtained by substituting them with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, and these acids. Anhydrides, dimers of lower alkyl esters and linoleic acid, other divalent organic acid monomers, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarabic acid, 1,2 , 4-cyclohexanetricarboxylic acid,
2,5,7-naphthalene tricarboxylic acid, 1,2,4-
Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,
Tridimerization of 3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer acid, anhydrides of these acids, etc. The above polyvalent carboxylic acid monomers can be mentioned. The epoxy resin used in the present invention is bisphenol A.
And a polycondensation product of epichlorohydrin, for example, Epomic R362, R364, R365, R36
6, R367, R369 (above Mitsui Petrochemical Industry Co., Ltd.)
Manufactured), Epotote YD-011, YD-012, YD-
014, YD-904, YD-017 (all manufactured by Toho Kasei Co., Ltd.), Epicoat 1002, 1004, 1007.
(These are manufactured by Shell Chemical Co., Ltd.) and other commercially available products.

The colorants 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, 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.

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, etc., and their surfaces treated with a resin or the like. The thing etc. are mentioned. Further, the toner of the present invention may further contain a magnetic material and be used as a magnetic toner. Examples of the magnetic material contained in the magnetic toner of the present invention include magnetite, hematite, iron oxides such as ferrite, metals such as cobalt and nickel, or aluminum or cobalt 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.

These ferromagnetic materials have an average particle size of 0.1 to 2
It is desirable that the amount is about 20 μm to 100 parts by weight of the resin component, particularly preferably 40 to 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 an additive 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.

The carrier core particles coated with a silicone resin in the present invention may be conventionally known ones, for example, ferromagnetic metals such as iron, cobalt and nickel; alloys and compounds such as magnetite, hematite and ferrite;
Examples thereof include glass beads. The average particle size of these core particles is usually 10 to 1000 μm, preferably 30 to 50 μm.
m. The amount of the silicone resin used is usually 1 to 10% by weight based on the carrier core particles.

The silicone resin used in the present invention may be any conventionally known silicone resin, for example, commercially available KR261, KR271, KR272, KR27 manufactured by Shin-Etsu Silicone Co., Ltd.
5, KR280, KR282, KR285, KR25
1, KR155, KR220, KR201, KR20
4, KR205, KR206, SA-4, ES100
1, ES1001N, ES1002T, KR3093 and Toray Dow Corning Silicone SR2100, S
R2101, SR2107, SR2110, SR210
8, SR2109, SR2115, SR2400, SR
2410, SR2411, SH805, SH806A,
SH840 or the like is 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 used in a silicone resin solution.
More preferably, add conductive fine powder and silane coupling agent.
It is prepared by dispersing with an appropriate mixer. Minute in coating layer
The conductive fine powder to be dispersed is about 0.01 to 5.0 μm.
It is preferable that the particle size be 100% by weight of the silicone resin.
It is preferable that 0.01 to 30 parts by weight is added.
More preferably 0.1 to 20 parts by weight. Conductive fine
The powder may be conventionally known carbon black,
Contact black, furnace black, thermal block
There is a rack. As a silane coupling agent, X is a compound represented by the formula:
R is a functional group₁~ R₃Is a hydrolyzable group. In particular
Aminosilane coupling agent in which X is an amino group is desired
Specifically, 0.1 to 1 per 100 parts by weight of silicone resin
Add 0 parts by weight, preferably 0.2-5 parts by weight
Yes. Examples of aminosilane coupling agents include γ-
(2-Aminoethyl) aminopropyltrimethoxysila
Γ- (2-aminoethyl) aminopropylmethyldiene
Methoxysilane, γ-anilinopropyltrimethoxyoxy
Orchid, octadecyl dimethyl [3- (trimethoxysilyl
) Propyl] ammonium chloride, etc.
It

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

[Manufacturing Example of Carrier] The manufacturing example of a carrier having several silicone resins in the coating layer is shown below.
These can be performed by known means. All parts are parts by weight.

[Production Example 1 of Carrier] (Composition of coating layer forming liquid) Silicone resin (KR206 Shin-Etsu Silicone) 100 parts by weight Carbon black (# 44 Mitsubishi Kasei) 3 parts by weight The above formulation and 100 parts by weight of toluene are mixed and homogenized. The mixture was dispersed for 30 minutes with a mixer to prepare a coating layer forming liquid. This coating layer forming liquid was used as spherical ferrite 100 having an average particle diameter of 100 μm.
A carrier A having a coating layer formed on the surface of 0 part by weight using a fluidized bed coating apparatus was obtained.

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

[0039] [Carrier manufacturing example 2]     100 parts of silicone resin     (SR2400 Toray Dow Corning Silicone)       Part 2 of tin oxide (S-1 Mitsubishi Metals)

[0040] [Carrier Manufacturing Example 3]     100 parts of silicone resin     (SR2400 Toray Dow Corning Silicone)     Carbon black (Ketjen Black Lion Akzo) 1.5 parts     γ-anilinopropyltrimethoxysilane 0.3 parts (SZ6083 Toray Dow Corning Silicone)

[0041] [Carrier Manufacturing Example 4]     Silicone resin (KR206 Shin-Etsu Silicone) 100 parts     Part 1 of carbon black (# 3600 Mitsubishi Kasei)     γ- (2-aminoethyl) aminopropyltrimethoxysilane 0.1 part     (SH6020 Toray Dow Corning Silicone)

[0042] [Carrier Manufacturing Example 5]     Silicone resin (KR206 Shin-Etsu Silicone) 100 parts     Carbon black (# 44 Mitsubishi Kasei) 1.5 parts     γ- (2-aminoethyl) aminopropyltrimethoxysilane 0.4 part     (SH6020 Toray Dow Corning Silicone)

An average particle size of 70 μ was applied to each of these coating layer forming liquids.
Carriers B, C, and D each having a coating layer formed on the surface of 1000 parts by weight of spherical ferrite of m using a fluidized bed type coating apparatus.
E each obtained.

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.

Next, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. C in the examples means "the abundance ratio of the charge control agent (a) on the toner surface per 1 g of the toner", and was determined by the following method.

[Abundance ratio of charge control agent (a) on toner surface per 1 g of toner] 100 mg of toner was precisely weighed, 50 ml of methanol was added, 20 glass beads having a diameter of 5 mm were added, an inner diameter of 33 mm and a depth of The mixture is stirred for 10 minutes in a 100 mm glass tube using a table-top ball mill and left standing at room temperature for 24 hours, after which the concentration of the supernatant is measured by an absorptiometer and calculated according to the Lambert-Beer law. Further, the fixing property and heat storability of the toner were also evaluated by the following methods.

[Evaluation of Fixability] Imagio Mf53 manufactured by our company
At 0, the fixing temperature was changed and a copy image with an image density of 1.2 by a Macbeth densitometer was obtained. 1 copy of each temperature with a clock meter equipped with sand eraser
After rubbing 0 times, the image densities before and after the measurement were measured, and the fixing ratio was calculated by the following formula. Fixing rate = image density after 10 times of sand eraser / previous image density × 100 (%) The temperature at which the fixing rate is 70% or more is defined as the lower limit fixing temperature.

[Evaluation of heat storability] A glass container was filled with toner and left in a constant temperature bath at 60 ° C. for 4 hours. This toner was cooled to 24 ° C. and subjected to a penetration test (JIS K2 235
Penetration was measured in -1991). The larger this value is, the better the heat storage stability is.

Example 1 Polyester resin 100 parts (Luna Pale 1447 manufactured by Arakawa Chemical Co., Ltd.) Carbon black 10 parts Exemplified compound a-1 1.5 parts Exemplified compound b-1 2 parts The mixture having the above composition is sufficiently stirred and mixed in a Henschel mixer. After that, roll mill at a temperature of 130 ~ 140 ℃ for 30
After heating and melting for a minute, and cooling to room temperature, the obtained kneaded product was pulverized and classified to obtain a black toner A having a particle size of 5 to 20 μm.
The abundance ratio c of the charge control agent (a) on the surface of the toner per 1 g of Toner A was 7.4 × 10 ⁻³ . 2.5 parts of Toner A and 97.5 parts of Carrier A were mixed by a ball mill to obtain a developer. Next, apply the developer described above to F
When it was set in T6960L and developed, a good image was obtained, and the image did not change even after outputting 120,000 images. When the toner charge amount was measured by the blow-off method, the initial charge amount was −20.2 μC / g, and the toner charge amount after running 120,000 sheets was −.
There was almost no difference from the initial value, which was 19.1 μC / g. There was also no toner filming on the photoconductor. Further, the lower limit temperature of fixing is 120 ° C., and the heat-preserving penetration is 18
It was mm.

Comparative Example 1 Example 1 except that the exemplified compound b-1 of Example 1 was not used.
A developer was obtained in the same manner as in 1. and an image test was performed. As the initial image, a clear image without fog was obtained, but from about 30,000 sheets, an unclear image with fog was formed, and toner filming was observed on the surface of the photoconductor. When the charge amount was measured in the same manner as in Example 1, the initial charge amount was -16.3.
μC / g, but after 30,000 sheets, -10.9 μC / g
It was as low as g.

Comparative Example 2 Example 1 except that the exemplified compound a-1 of Example 1 was not used.
When a developer was obtained in the same manner as in (1) and an image test was conducted, an unclear image with a lot of fog was obtained.

Comparative Example 3 Toner B was obtained in the same manner as in Example 1 except that 2.5 parts of the exemplified compound a-1 of Example 1 was used (c = 21 × 10 ⁻³ g /
g). A developer was obtained in the same manner as in Example 1 and an image test was conducted. As the initial image, a clear image without fog was obtained, but from about 50,000 sheets, an unclear image with fog was formed, and toner filming was observed on the surface of the photoconductor. Also,
When the charge amount was measured in the same manner as in Example 1, the initial charge amount was −20.9 μC / g, but after 50,000 sheets, −
It was as low as 9.9 μC / g.

Comparative Example 4 Toner C was obtained in the same manner as in Example 1 except that 1 part of Exemplified Compound a-1 of Example 1 was used (c = 6.1 × 10 ⁻³ g / g).
g). When a developer was obtained and an image test was conducted in the same manner as in Example 1, an unclear image with a lot of fog was obtained.

Example 2 Styrene / 2-ethylhexyl acrylate copolymer 100 parts Polypropylene 5 parts Carbon black 10 parts Exemplified compound a-1 2 parts Exemplified compound b-2 2 parts A raw material mixture having the above composition was prepared in the same manner as in Example 1. , Melt kneading,
After cooling, pulverizing and classifying, a black toner D having a particle diameter of 5 to 25 μm was obtained (c = 16.5 × 10 ⁻³ g / g). An image test was conducted in the same manner as in Example 1, except that the toner D and the carrier C were used.
A clear and good image was obtained, and the image did not change even after 150,000 sheets were printed. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was −23.2.
μC / g, and the toner charge amount after running 150,000 sheets was −21.5 μC / g, which was almost the same as the initial value. There was also no toner filming on the photoconductor. Further, the lower limit temperature of fixing was 140 ° C., and the penetrability of heat storability was 10 mm.

Example 3 The same test as in Example 2 was carried out except that the carrier D was used. As a result, a clear and good image was obtained, and the image did not change after 180,000 images were printed. When the toner charge amount was measured by the blow-off method, the initial charge amount was −25.1 μC / g, and the toner charge amount after running 180,000 sheets was −22.0 μC / g, which is almost the initial value. There was no difference. There was also no toner filming on the photoconductor.

Example 4 Polyester resin 100 parts (Luna Pale 1447 manufactured by Arakawa Chemical Co., Ltd.) Polypropylene 5 parts Carbon black 10 parts Exemplified compound a-1 2 parts Exemplified compound b-2 2 parts A mixture of the above composition was prepared in the same manner as in Example 1. , Thoroughly mix in a Henschel mixer, then roll mill to 130-1
After heating and melting at 40 ° C for 30 minutes and cooling to room temperature,
The resulting 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), 0.1 part of hydrophobic colloidal silica
Toner E was obtained by thoroughly mixing the above parts with a speed kneader. This toner is loaded into a developing device as shown in FIG.
When continuous copying was performed and an image test was performed, a good image was obtained. The image did not change after 50,000 images were printed.

This developing method will be described. 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 is supplied to the sponge roller 4. And
The toner taken into the sponge roller 4 is rotated in the direction of the arrow by the sponge roller, and the toner conveying member 2
Transported to, rubbed, electrostatically or physically adsorbed,
The toner conveying member 2 strongly rotates in the direction of the arrow, a uniform thin toner layer is formed by the elastic blade 3, and the toner is triboelectrically charged. After that, the toner is conveyed to the surface of the electrostatic latent image carrier 1 which 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. In order to measure the specific charge amount Q / M of the toner on the toner conveying member, the toner on the toner conveying member is sucked through a Faraday cage equipped with a filter layer on the outlet side and trapped in the Faraday cage. According to the suction method specific charge amount measurement layer value for measuring the specific charge of the toner thus obtained, it was confirmed that Q / M was measured and that the toner was sufficiently charged with -13.8 μC / g. In addition, the charge amount in running 50,000 sheets was -10.9 μC / g, which was almost the same as the initial value. Further, even under high humidity and low humidity, the image quality equivalent to normal humidity was obtained with the charge amounts of −10.5 and 12.6 μC / g, respectively. Further, there was no toner filming on the photoconductor, the toner conveying member and the elastic blade. Further, the lower limit temperature of fixing was 117 ° C., and the penetrability of heat storability was 20 mm.

Example 5 Epoxy resin 100 parts Carnauba wax (melting point 83 ° C.) 5 parts Carbon black 8 parts Exemplified compound a-1 1 part Exemplified compound b-3 5 parts A mixture of the above composition was prepared in the same manner as in Example 1 by using Henschel. After thoroughly stirring and mixing in a mixer, roll mill to 130-1
After heating and melting at 40 ° C for 30 minutes and cooling to room temperature,
The resulting kneaded product was pulverized and classified to obtain a black toner F having a particle size of 5 to 20 μm (c = 8.3 × 10 ⁻³ g / g). 97.5 parts of Carrier E was mixed in a ball mill with 2.5 parts of Toner F to obtain a developer. Next, the above developer was set in a 6960L manufactured by our company and developed, and a good image was obtained, and the image did not change even after 180,000 sheets of images were printed. 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 180,000 sheets is -2
There was almost no difference from the initial value of 5.3 μC / g. There was also no toner filming on the photoconductor. Further, the lower limit temperature of fixing is 110 ° C., and the heat storability is 20 m.
It was m.

[0059]

The toner for developing an electrostatic image of the present invention contains 1 g of toner by using the charge control agents (a) and (b) together.
By setting the abundance ratio of the charge control agent (a) on the surface of the toner to 7 × 10 ^{−3 to} 20 × 10 ⁻³ , the initial charge characteristics are good, and the carrier of the charge control agent during continuous use is The decrease in the amount of charge due to surface contamination is small.
Further, in the present invention, by using the above-mentioned two kinds of charge control agents in combination, the most suitable negative charge control agent for low temperature fixing toner, which shows good charging characteristics even when the binder resin is a polyester resin or an epoxy resin, is selected. can get.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a developing device used in the present invention.

[Explanation of symbols]

1 Electrostatic latent image carrier 2 Toner transport member 3 elastic blade 4 Sponge roller 5 stirring blades 6 toner 7 Toner tank

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 9/097 G03G 9/087 G03G 9/113

Claims (3)

(57) [Claims] 1. A toner containing a binder resin, a colorant and a charge control agent as main components, wherein the following components (a) and (b) are used together as a charge control agent, and charge control on the toner surface per 1 g of the toner is performed. An electrostatic charge image developing toner, wherein the abundance ratio of the agent (a) is 7 × 10 ^{−3 to} 20 × 10 ⁻³ g / g. [Charge control agent (a)] [Charge Control Agent (b)] Copolymer of Styrene / Acrylic Monomer and Sulfonic Acid-Containing Acrylamide Monomer 2. The toner for developing an electrostatic charge image according to claim 1, wherein the binder resin is a polyester resin. 3. A two-component developer comprising a toner and a carrier according to claim 1, wherein the carrier has a silicone resin coating layer, and the coating layer contains conductive fine powder and a silane coupling agent. An electrophotographic developer characterized by the above.