JPH10274859A - Developer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure such satisfactory hardness as not to hinder productivity and to improve anti-offsetting property, fixability, anti-smearing property, flowability and aggregation resistance by incorporating a colorant and specified resin binders. SOLUTION: This developer contains a colorant, a 1st resin binder contg. 1st wax and 2nd wax added at the time of polymn. and a 2nd resin binder contg. 1st wax and 2nd wax added at the time of polymn. The mol.wt. of the 2nd resin binder is higher than that of the 1st resin binder. The 1st and 2nd resin binders are selected from among (co)polymers of styrene and its substitution product such as a styrene homopolymer and hydrogenated styrene resin, acrylic resin such as poly(methyl)methacrylate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer used in an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art In electrophotography, an electrostatic image formed on a photoreceptor is usually developed with a toner containing a pigment, and the obtained toner image is transferred onto a transfer paper and fixed by a hot roll or the like. The photoreceptor is cleaned to form the next electrostatic image. Toner requires various physical and chemical properties. However, many of the known toners have some defects as described below.

For example, many toners that are easily melted by heating tend to aggregate during storage or in a copying machine. Many toners have poor triboelectric and flow properties due to environmental temperature changes.

In addition, the quality of a copy obtained is reduced due to the collision of carrier particles with toner particles due to repeated development due to continuous use, and the mutual deterioration of the toner carrier particles and the photoconductor due to their contact with the surface of the photoreceptor. Many phenomena occur.

[0005] Among these phenomena, there are phenomena caused by brittleness of toner particles. If the toner is brittle, it is easily crushed by mechanical force, which is preferable from the viewpoint of manufacturability. However, even in a developing device, such a toner is easily pulverized and pulverized by a load applied to the toner, and contaminates the carrier surface and the developing sleeve, and the charge control of the toner particles themselves becomes incomplete, It causes undesirable phenomena such as fog. Thus, the brittleness (brittleness) of the toner is greatly related to the life of the developer.

In order to avoid the above-mentioned deterioration phenomenon, it is conceivable to use a high molecular weight polymer as the binder resin. However, the temperature at the time of fixing must be set high, and a large amount of heat is required. Therefore, using a binder resin having a too high molecular weight is not preferable in terms of energy saving. Although a method of adding a small amount of a plasticizer to a toner has also been proposed, the method is put to practical use because there is a problem that the free flowing property of the toner is impaired and a carrier is contaminated. On the other hand, if the toner is too hard, the mechanical pulverization efficiency and the yield during production decrease, and a problem in cost arises.

For the above reasons, relatively low molecular weight polystyrene or styrene-butyl methacrylate copolymer having appropriate hardness has been used as a binder resin for toner. At the present time when the reliability of a copying machine is regarded as important, the hardness of the binder resin is insufficient and a material having a higher hardness is required. However, such a binder resin having a high hardness does not have sufficient properties suitable for a fixing method using a heat roller. For example, by fusing and pressing the toner by heat, fixing to paper or other transfer material can be easily performed. However, even if a binder resin having high hardness is used, it is difficult to avoid contamination (offset phenomenon) of the roller due to toner adhesion to the heat roller. In order to prevent the offset phenomenon, for example, a silicone oil or the like can be applied to the roller. However, maintenance becomes complicated and there is a problem in cost. From such a thing,
There is a need for improved offset resistance of the toner itself.

For the purpose of improving the fixing characteristics, offset resistance, improvement of fixing power, etc., it has been reported to improve the toner by adding a low molecular weight polyolefin or other plasticizer as a release agent (wax) to the toner. .

However, the use of the release agent promotes agglomeration between toner particles, and tends to cause a decrease in toner fluidity. If the dispersibility with the binder resin is poor, the release agent is released on the surface of the toner particles, and the release agent is agglomerated and adheres to the photoreceptor, causing a black spot or a pulverizing chamber during the production of the toner. There is a problem that the recovery rate decreases due to adhesion to manufacturing members such as As described above, the amount of the release agent to be added is limited, and therefore, the improvement by the release agent is limited.
Further, the use of the release agent tends to cause problems such as adverse effects due to the release agent, such as a decrease in offset resistance, a decrease in the residual fixing rate, and generation of smear.

[0010] From the above, it is considered that improvement of the resin component, which is the main component of the binder, is the most important. For example, 2
There has been proposed a method of adjusting the hardness of the toner and improving the fixing property by mixing resins having different molecular weight ranges. However, even when resin components having a plurality of types of molecular weights are mixed, both the fixing power and the anti-offset property at the time of heat fixing by a hot roll have not been sufficiently satisfied.

[0011]

The object of the present invention is to improve a developer containing two or more kinds of binder resins having different molecular weights and a wax, and an object of the present invention is to provide a developer having a sufficient hardness without impairing the productivity. Holding and offset resistance, fixability,
An object of the present invention is to provide a developer excellent in smear property, fluidity, aggregation resistance and the like.

[0012]

According to the present invention, first, a colorant, a first wax and a second wax different from the first wax are added to a first molecular weight internally added during polymerization. Wherein the first wax and the second wax are internally added during polymerization and have a second binder resin having a second molecular weight higher than the first molecular weight. Is provided.

[0013] Secondly, the present invention relates to a colorant having a molecular weight of 1,
A first binder resin having a molecular weight of 10,000 to 100,000, wherein a polypropylene wax having a molecular weight of 10,000 to 10,000 and a polyethylene wax having a molecular weight of 1,000 to 10,000 are internally added during polymerization; A developer, wherein a polyethylene wax is internally added during polymerization and a second binder resin having a molecular weight of 100,000 to 500,000 is provided.

The present invention provides, in a third aspect, a first binder resin having a first molecular weight, in which a coloring material, a first wax and a second wax different from the first wax are internally added during polymerization. A second binder resin having a second molecular weight higher than the first molecular weight, wherein the first wax and the second wax are internally added at the time of polymerization;
Wherein the wax and the second wax are internally added at the time of polymerization and include a third binder resin having a third molecular weight higher than the second molecular weight.

Fourth, the present invention provides a colorant having a molecular weight of 1,
A first binder resin having a molecular weight of 10,000 to 100,000, wherein a polypropylene wax having a molecular weight of 10,000 to 10,000 and a polyethylene wax having a molecular weight of 1,000 to 10,000 are internally added during polymerization; Polyethylene wax is internally added during polymerization, and the second binder resin having a molecular weight of 50,000 to 250,000, and the polypropylene wax and the polyethylene wax are internally added during polymerization, and have a molecular weight of 100,000 to 500,000. And a third binder resin having the following formula:

Fifth, the present invention provides a colorant having a molecular weight of 1,
35 to 55% by weight of a first binder resin having a molecular weight of 10,000 to 100,000, in which polypropylene wax of 000 to 30,000 and polyethylene wax of 1,000 to 10,000 are internally added during polymerization.
And the polypropylene wax and the polyethylene wax are internally added at the time of polymerization, and 50,000 to 250,
Second binder resin having a molecular weight of 000
% By weight, the polypropylene wax and the polyethylene wax are internally added during polymerization, and
45 to 65% by weight of a third binder resin having a molecular weight of 500,000, and the polypropylene wax is 1.6 to 6.0% by weight based on the total amount of the binder resin, and the polyethylene wax is based on the total amount of the binder resin. And 0.1 to 2.0% by weight of the developer.

The present invention provides, sixthly, a first wax, a first wax,
A first binder resin production step of producing a first binder resin having a first molecular weight by performing polymerization using a solution containing a second wax different from the wax and a first resin monomer, Polymerization is performed using a solution containing the first wax, the second wax, and a second resin monomer to produce a second binder resin having a second molecular weight larger than the first molecular weight. A second binder resin production step to be performed, a first binder resin, a second binder resin, a melt kneading step of melt kneading a mixture containing a coloring material, and the obtained melt kneaded material is pulverized, And a toner particle manufacturing step of manufacturing toner particles.

Seventh, the present invention provides a method for producing a polymer having a molecular weight of 1,000 to 3
000 polypropylene wax, molecular weight 1,000
Polymerization is carried out using a solution containing 0 to 10,000 polyethylene wax and the first resin monomer, and
A first binder resin production process for producing a first binder resin having a molecular weight of 0 to 100,000, and a polypropylene wax having a molecular weight of 1,000 to 30,000 and a polyethylene wax having a molecular weight of 1,000 to 10,000. A second binder resin production step of performing polymerization using a solution containing a second resin monomer to produce a second binder resin having a molecular weight of 100,000 to 500,000; A melt-kneading step of melt-kneading a mixture containing a resin, a second binder resin, and a colorant; and a toner particle manufacturing step of pulverizing the obtained melt-kneaded material to produce toner particles. And a method for producing a developer.

Eighth, the present invention provides a molecular weight of 1,000 to 3
A first mixture comprising 1.0 to 6.0% by weight of a propylene polypropylene of 000, 0.1 to 2.0% by weight of a polyethylene wax having a molecular weight of 1,000 to 10,000, and a first resin monomer; Polymerization is carried out using 10,000
A first binder resin production process for producing a first binder resin having a molecular weight of １００100,000, 1.0-6.0% by weight of polypropylene wax having a molecular weight of 1,000-30,000, and a molecular weight of 1,000. -10,
And a second binder resin having a molecular weight of 50,000 to 250,000 by polymerization using a second mixture containing 0.1 to 2.0% by weight of polyethylene wax and 0.1 to 2.0% by weight of a second resin monomer. In a second binder resin manufacturing process, 1.0 to 6.0% by weight of a polypropylene wax having a molecular weight of 1,000 to 30,000, and a polyethylene wax having a molecular weight of 1,000 to 10,000.
Polymerization was carried out using a third mixture containing 1 to 2.0% by weight and a second resin monomer, and 100,000 to 500,
A second binder resin producing step of producing a third binder resin having a molecular weight of 000, wherein the first binder resin is 35 to 55% by weight and the second binder resin is 0 to 20% by weight based on the total amount of the binder resin. A melt-kneading step of melt-kneading a mixture containing 45 to 65% by weight of the third binder resin and a coloring material to obtain a melt-kneaded material, and pulverizing the obtained melt-kneaded material to obtain a toner. Provided is a method for producing a developer, comprising a toner particle producing step of producing particles.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies to improve a developer using at least two kinds of binder resins having different molecular weights. To fix the toner,
It is necessary that the toner is softened by the heat given by the hot roll, the toner flows by the pressure applied by the hot roll, and sufficient contact between toner particles or between toner and paper occurs. From the viewpoint of energy saving, the toner must be soft at a low temperature and have a low viscosity. Therefore, it is desirable that the binder resin constituting the toner has a low molecular weight.

On the other hand, in order to prevent the offset phenomenon, it is necessary that the wetting between the hot roll and the toner is poor. Of course, the toner is separated into a portion where the toner adheres to the paper and a portion where the toner adheres to the hot roll. It is necessary that a strong cohesive force acts between the molten toners so as not to be caused. In order to obtain this cohesive force, it is preferable to use what is called “entanglement” between the binder resin molecules, and for that purpose, it is desirable to use a binder resin having a high molecular weight.

The factor that the molecular weight of the binder resin is preferably low for sufficiently fixing at a low temperature and the seemingly contradictory element that the molecular weight is preferably high for preventing the offset phenomenon are as follows. It is thought that it is possible to satisfy simultaneously by using both of the molecular weight components.

In order to fix the developer at the lowest possible temperature, it is desirable that the molecular weight of the low molecular weight component is as low as possible. However, if the temperature is too low, solidification tends to occur during storage of the toner or in the developing device. On the other hand, in order to prevent the offset phenomenon from occurring as high as possible, it is desirable to make the molecular weight of the high molecular weight component as high as possible. However, in the method of making the molecular weight of the low molecular weight component as low as possible and increasing the molecular weight of the high molecular component as much as possible, the difference between the highest temperature at which no offset occurs during fixing and the lowest fixing temperature at which a sufficient fixing rate is obtained is obtained. There is not much, but it may worsen. As a result, problems such as image roughening and image quality deterioration occur.

That is, when the difference in melt viscosity between the low molecular weight component and the high molecular weight component is very large, the low molecular weight component and the high molecular weight component are uniformly dispersed when the toner is adjusted by means such as melt kneading. And a coarse dispersion state is exhibited. In such a case, toner particles rich in the low molecular weight component and toner particles rich in the high molecular weight component are formed, and the toner particles rich in the low molecular weight component easily cause an offset phenomenon, and the toner particles rich in the high molecular weight component adversely affect the fixing rate. Will be exerted.

For this reason, it is desirable not only to adjust the molecular weight of the high molecular weight component and the molecular weight of the low molecular weight component, but also preferably to appropriately adjust the mixing ratio of the two. Further, as a method of preventing the offset phenomenon, in the toner particles,
For example, by including a low softening point wax consisting of a release agent such as polypropylene wax polyethylene wax,
There is a means for lowering the minimum fixing temperature. However,
According to this method, since the fluidity of the powdery toner particles is reduced, the developability and the transferability are reduced, so that a good image is not formed and the toner particles tend to be cohesive. Moreover, in order to obtain the effect of the addition of the wax, it is necessary to considerably increase the content of the wax. As a result, the wax component adheres to the developing sleeve and the electrostatic image support to form a film. However, there is a drawback that its function is hindered.

Further, in order to improve the fluidity of the toner particles, it is effective to add a fluidity improver composed of hydrophobic silica fine powder to the toner powder. In order to impart sufficient fluidity to the toner containing the low softening point wax, it is necessary to add a large amount of hydrophobic silica fine powder. However, the surface of the electrostatic image support is damaged by the fine silica powder having high hardness, which causes deterioration of image quality.

A toner containing a wax having a low softening point is usually produced by melt-kneading a binder resin together with a coloring agent, a wax, a charge control agent and other toner components, and finely pulverizing the resulting mass. However, in such a method, the content of the wax is limited in terms of compatibility. Even if a sufficient amount is contained, the toner cannot be sufficiently uniformly dispersed in the toner particles, and the wax is free and present on the surface of the toner particles, which causes deterioration of the toner fluidity.

The present inventors have accomplished the present invention based on the above considerations. The developer of the present invention is roughly classified into the following eight viewpoints. According to a first aspect of the present invention, a coloring material;
A first binder resin having a first molecular weight, in which a first wax and a second wax different from the first wax are internally added during polymerization, and the first wax and the second wax are polymerized. And a second binder resin having a second molecular weight higher than the first molecular weight, sometimes added internally.

In the invention according to the first aspect, as the binder resin material, two or more binder resin materials having different molecular weights are used. Two or more similar waxes are internally added to each binder resin material at the time of polymerization thereof.

As the binder resin material, at least two kinds of binder resins having different molecular weights, for example, two kinds of resins of high molecular weight and low molecular weight can be used. By using such plural kinds of binder resins, the wax in the toner can be more uniformly dispersed.
As a result, a developer having good toner fluidity and storage stability can be obtained.

According to a second aspect of the present invention, a preferred embodiment of the invention according to the first aspect is provided. According to a second aspect, a colorant, a first binder resin having a first molecular weight, in which a first wax and a second wax different from the first wax are internally added during polymerization, And a second wax having a second molecular weight higher than the first molecular weight, wherein the first binder resin is 1
The second binder resin has a molecular weight of 100,000-500,000, and the first wax has a molecular weight of 1,000-3,000.
The second wax is a polyethylene wax having a molecular weight of 1,000 to 10,000.

According to a third aspect of the present invention, the first
A further preferred aspect of the invention according to the aspect is provided.
According to a third aspect, at least three of a polymer, a medium molecule, and a low molecule containing the colorant and the first and second waxes.
A developer mixed with a kind of binder resin is shown. 3
By using various kinds of binder resins, the wax in the toner can be more uniformly dispersed. As a result, a developer having better toner fluidity and storage stability can be obtained.

According to a fourth aspect of the present invention, there is provided a further preferred aspect of the third aspect. In the binder resin, a first binder resin having a molecular weight of 10,000 to 100,000 and 50,000 to 250, 250,
A second binder having a molecular weight of 000;
And a third binder resin having a molecular weight of 000 to 500,000. As these binder resins, polypropylene wax having a molecular weight of 1,000 to 30,000 and polyethylene wax having a molecular weight of 1,000 to 10,000 are used.

According to a fifth aspect of the present invention, there is provided a still further preferred embodiment of the third aspect. In the binder resin, 35 to 55% by weight of the first binder resin having a molecular weight of 10,000 to 100,000;
0 to 20% by weight of a second binder having a molecular weight of 0000 to 250,000, and 100,000 to 500,
Third binder resin 45-6 having a molecular weight of 000
5% by weight are mixed. In these binder resins, a polypropylene wax having a molecular weight of 1,000 to 30,000 is used in an amount of 1.6 to 6.0 with respect to the total amount of the binder resin.
% By weight, polyethylene wax having a molecular weight of 1,000 to 10,000 is 0.1 to 2.0 with respect to the total amount of the binder resin.
% By weight.

As shown in the above second, fourth and fifth aspects, according to the present invention, the molecular weight of the binder resin and the wax, preferably the ratio of each binder resin and the wax content are further limited. This gives the toner an appropriate hardness, controls the wax amount, molecular weight, wax dispersibility, etc. within an appropriate range, and has good fixability, offset resistance, storage properties, fluidity, etc. A developer with good pulverization efficiency at the time is obtained. In addition, when such a developer is used, development and transfer are performed well, and an excellent image is obtained.

Further, a sixth aspect of the present invention shows a method for producing a developer according to the first aspect. According to a sixth aspect,
Polymerization is performed using a solution containing a first wax, a second wax different from the first wax, and a first resin monomer to produce a first binder resin having a first molecular weight. A first wax, a second wax different from the first wax, and a second wax.
The polymerization is carried out using a solution containing the resin monomer of
A second binder resin producing step of producing a second binder resin having a second molecular weight larger than the molecular weight of the first binder resin, the second binder resin,
And a melt-kneading step of melt-kneading the mixture containing the mixture and the colorant, and a toner particle manufacturing step of pulverizing the melt-kneaded material to produce toner particles. Is obtained.

The seventh aspect shows a method for producing a developer according to the second aspect of the present invention. According to a seventh aspect,
Polymerization is carried out using a solution containing a polypropylene wax having a molecular weight of 1,000 to 30,000, a polyethylene wax having a molecular weight of 1,000 to 10,000 and a first resin monomer, and a molecular weight of 10,000 to 100,000. A first binder resin producing step of producing a first binder resin having a molecular weight of 1,000 to 30,000 and a molecular weight of 1,000 to 10,000.
Of 100,000 to 50,000 using a solution containing a polyethylene wax and a second resin monomer.
A second binder resin production process for producing a second binder resin having a molecular weight of 0000, and a mixture containing the first binder resin, the second binder resin, and a coloring material, which is melt-kneaded, and melt-kneaded. And a toner particle producing step of producing the toner particles by pulverizing the obtained melt-kneaded product.

Further, an eighth aspect of the present invention shows a method for producing a developer according to the fifth aspect. According to an eighth aspect, a polypropylene wax having a molecular weight of 1,000 to 30,000 1.0 to 6.0% by weight, a molecular weight of 1,000 to 1
Polymerization is carried out using a first mixture containing 0.1 to 2.0% by weight of a polyethylene wax of 0000 and a first resin monomer, and a first mixture having a molecular weight of 10,000 to 100,000. First binder resin production process for producing a binder resin, polypropylene wax having a molecular weight of 1,000 to 30,000 1.0 to 6.0% by weight, and polyethylene wax having a molecular weight of 1,000 to 10,000 0.1 to A second resin containing 2.0% by weight and a second resin monomer;
Of 50,000 to 25%.
A second binder resin production process for producing a second binder resin having a molecular weight of 000,
0 ~ 30,000 polypropylene wax 1.0 ~
Polymerization using a third mixture containing 6.0% by weight and 0.1 to 2.0% by weight of polyethylene wax having a molecular weight of 1,000 to 10,000 and a second resin monomer,
A third having a molecular weight of 100,000 to 500,000
A second binder resin production process for producing the binder resin, the first binder resin being 35 to 55% by weight, the second binder resin being 0 to 20% by weight, and the third binder resin being based on the total amount of the binder resin. 45-45 binder resin
A melt kneading step of melt-kneading a mixture containing 65% by weight and a coloring material to obtain a melt-kneaded material; and a toner particle manufacturing step of pulverizing the obtained melt-kneaded material to produce toner particles. A method for producing a developer is provided.

Next, an example of an image forming apparatus to which the developer according to the present invention can be applied will be schematically described with reference to FIG. In the figure, reference numeral 1 denotes a photosensitive drum which is provided rotatably in the direction of the arrow and which carries an image. Around the photosensitive drum, a charging charger 2, an erasing array 3, an exposure unit 4, a developing device 5, a transfer / peeling charger 6, 7, a cleaning device 8, and a static elimination charger 9 are sequentially provided according to the rotation direction. An image forming unit 10 is formed.

A pair of aligning rollers 11 for aligning the sheet is provided below the developing device 5, and a guide for guiding the sheet is provided between the pair of aligning rollers 11 and the photosensitive drum 1. A body 12 is provided.

Further, below the cleaning device 8,
A transport belt 13 that transports the sheet is provided. When an image is formed, an original is set on an original glass, and the original is irradiated with light from an exposure lamp (not shown). The reflected light from the document is imaged on the peripheral surface of the photosensitive drum 1 via the optical system.
It is charged by the charging charger 2, and an electrostatic latent image of the document is formed by the image formation. This electrostatic latent image is
When the photosensitive drum 1 rotates, the photosensitive drum 1 is sent to the developing device 5, where the developer is supplied to visualize the image.

On the other hand, at this time, paper is supplied from a paper feed cassette (not shown), and after the paper is aligned by the aligning roller pair 11, the photosensitive drum 1
Is transferred by the transfer charger 6.

The sheet on which the image has been transferred is peeled off from the photosensitive drum 1 by the action of the peeling charger 7 and is conveyed by the traveling of the conveyor belt 13. The sheet is sent to a fixing device (not shown), where the transferred image is fixed and discharged.

As the first and second binder resins used in the developer of the present invention, for example, a resin selected from a copolymer of styrene and a substituted product thereof, an acrylic resin, and the like can be used. It can be adjusted and used so as to satisfy the characteristics based on the eighth viewpoint.

Examples of the copolymer of styrene and its substituted product include polystyrene homopolymer, hydrogenated styrene resin, styrene-isobutylene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene terpolymer. Acrylonitrile-styrene-acrylic ester terpolymer, styrene-acrylonitrile copolymer, acrylonitrile-acrylic rubber-styrene terpolymer, acrylonitrile-chlorinated polystyrene-styrene terpolymer, acrylonitrile-EVA- Styrene terpolymer, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer,
Styrene-butadiene rubber, styrene-maleic acid ester copolymer, styrene-isobutylene copolymer, styrene-maleic anhydride copolymer and the like can be mentioned.

Examples of the acrylic resin include polyacrylate, polymethyl methacrylate, polyethyl methacrylate, poly-n-butane methacrylate, and the like.
Polyglycidyl methacrylate, polyfluorinated acrylate, styrene-methacrylate copolymer, styrene
Butyl methacrylate copolymer, styrene-ethyl acrylate copolymer and the like.

In addition, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, phenol resin, urea resin, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, terpene resin, aliphatic Alternatively, an alicyclic hydrocarbon resin, an aromatic petroleum resin, chlorinated paraffin, paraffin wax or the like can be used alone or as a mixture as a binder resin.

As the coloring material used in the developer of the present invention, carbon black, organic or inorganic pigments and dyes, and the like are used. Although there is no special restriction, carbon black includes acetylene black, furnace black, thermal black, channel black, Ketjen black and the like, and facial dyes include, for example, First Yellow G, Benzidine Yellow, Indofast Orange, Irgazine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Risor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Phthalocyanine Blue, Pigment Blue,
Brilliant green B, phthalocyanine green, quinacridone and the like. These can be used alone or as a mixture.

The wax used in the present invention includes, for example, Hoechst A. G. FIG. Brand name PE130, Sanyo Chemical Co., Ltd. Brand name Viscol 550F, Company name Biscol 330P, Mitsui Petrochemical Co., Ltd.
Mitsui High Wax 440P, brand name Mitsui High Wax 200P, Hoechst A. G. FIG. Wax C manufactured by Nippon Kasei Co., Ltd. A wax selected from Bisamide A or the like is used in combination with the first to eighth waxes described above.
Can be adjusted to satisfy the characteristics based on the above viewpoint. In addition, paraffin wax, natural wax, and the like can be used.

Examples of the charge controlling agent used in the developer of the present invention include metal complexes of monoazo dyes, metal complexes of salicylic acid, oxynaphthoic acid, and dicarboxylic acids such as Co, Cr and Fe; sulfonated copper phthalocyanine pigments; Styrene oligomer, chlorinated paraffin, melamine resin, etc. into which a group or halogen is introduced.

As external additives that can be used in the developer of the present invention, silica particles, metal oxide fine particles, cleaning aids and the like are used. Examples of the silica particles include silicon dioxide, aluminum silicate, sodium silicate, potassium silicate, zinc silicate, and magnesium silicate. Examples of the metal oxide fine particles include zinc oxide, titanium oxide, aluminum oxide, zirconium oxide, strontium titanate, and barium titanate.

Examples of the cleaning aid that can be used in the developer of the present invention include fine resin powders such as polymethyl methacrylate, polyvinylidene fluoride, and polytetrafluoroethylene. These external additives may have been subjected to a surface treatment such as hydrophobicity.

[0053]

EXAMPLES First, a plurality of types of binder resins having different molecular weights were produced as follows. Production of Binder Resin High molecular weight, medium molecular weight, and low molecular weight binder resins were produced as described below.

High molecular weight binder resin In a solvent such as water, a nonionic emulsifier, an anionic emulsifier, or an aqueous mixture of potassium persulfate, 60 parts by weight of a styrene monomer and 40 parts by weight of a methacrylic acid ester monomer are added. While stirring the mixture, a polypropylene wax having a molecular weight of 1,000 to 30,000 and a polyethylene wax having a molecular weight of 1,000 to 10,000 are mixed at a ratio shown in Table 1 with respect to the styrene monomer and the methacrylic acid ester monomer. High molecular weight binder resins of 100,000 to 500,000 were obtained.

Medium molecular weight binder resin In a solvent such as a nonionic emulsifier, an anionic emulsifier, or an aqueous mixture of potassium persulfate, a styrene monomer 6
0 parts by weight and 40 parts by weight of the methacrylic acid ester monomer were added, and the resulting solution mixture was stirred with a molecular weight of 10
A polypropylene wax having a molecular weight of from 1,000 to 10,000 and a polyethylene wax having a molecular weight of from 1,000 to 10,000.
The styrene monomer and the methacrylic acid ester monomer were mixed in the proportions shown in Table 1 and polymerization was carried out with stirring to obtain a medium molecular weight binder resin having a molecular weight of 50,000 to 250,000.

Low molecular weight binder resin A styrene monomer 6 in a solvent such as a nonionic emulsifier, an anionic emulsifier, and an aqueous mixture of potassium persulfate.
0 parts by weight and 40 parts by weight of the methacrylic acid ester monomer were added, and the resulting solution mixture was stirred with a molecular weight of 10
A polypropylene wax having a molecular weight of from 1,000 to 10,000 and a polyethylene wax having a molecular weight of from 1,000 to 10,000.
The styrene monomer and the methacrylic acid ester monomer were mixed at the ratios shown in Table 1 and polymerization was carried out with stirring to obtain a low molecular weight binder resin having a molecular weight of 10,000 to 100,000.

Each of the obtained binder resins was mixed at a mixing ratio shown in Table 1 below, and binder resin compositions A to O were mixed.
I got Binder resin (polymer: H-form, medium molecular:
The M-form, low-molecular-weight: L-form) and the amount of wax added (content% based on 100% by weight of the binder resin) are shown.

[0058]

[Table 1]

In the table, the high molecular weight polymer was H, the middle molecular weight was M, and the low molecular weight was L in the binder resins. H body ・ M
The molecular weight of the body / L body and the molecular weight of the PP (polypropylene) wax / PE (polyethylene) wax are as follows.

H-form: 100,000-500,000 M-form: 50,000-250,000 L-form: 10,000-100,000 PP wax: 1,000-30,000 PE wax: 1,000- 10,000 (Example 1) 100% by weight of binder resin A in Table 1
6% by weight of carbon black (MA-100, manufactured by Mitsubishi Kasei Kogyo) and 0.2% by weight of a charge control agent (Copy Blue, manufactured by Hoechst Japan) are uniformly mixed. Next, the mixture was kneaded at 125 ° C. for 30 minutes using a pressurized kneader, and after the obtained mixture was cooled, coarsely pulverized with a hammer mill, and further with an I-type jet mill-DS classifier (NPK). Finely pulverized and classified so as to have an average particle diameter of 10 to 15 μm to obtain a fine toner powder. 100% by weight of this toner fine powder
0.35% by weight of hydrophobic silica fine powder (HDK-2050, manufactured by Hoechst Industries) and 0.1 of aluminum oxide fine particles (AKP-3000, manufactured by Sumitomo Chemical Co., Ltd.)
By weight addition, an electrophotographic toner was obtained.

Example 2 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin B shown in Table 1 was used as the binder resin.

Example 3 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin C shown in Table 1 was used as the binder resin.

Example 4 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin D shown in Table 1 was used as the binder resin.

Example 5 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin E shown in Table 1 was used as the binder resin.

Example 6 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin F shown in Table 1 was used as the binder resin.

Example 7 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin G shown in Table 1 was used as the binder resin.

Example 8 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin H shown in Table 1 was used as the binder resin.

Example 9 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin J shown in Table 1 was used as the binder resin.

Example 10 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin K shown in Table 1 was used as the binder resin.

Example 11 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin L shown in Table 1 was used as the binder resin.

Comparative Example 1 An electrophotographic toner was obtained in the same manner as in Example 1, except that the resin I shown in Table 1 was used as the binder resin.

Comparative Example 2 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin M shown in Table 1 was used as the binder resin. Comparative Example 3 An electrophotographic toner was obtained in the same manner as in Example 1, except that the resin N shown in Table 1 was used as the binder resin.

Comparative Example 4 An electrophotographic toner was obtained in the same manner as in Example 1 except that the resin O shown in Table 1 was used as the binder resin. For each of the toners obtained in Examples and Comparative Examples, a ferrite carrier manufactured by Powder Tech (average particle diameter: 45 μm)
m), and uniformly stirred and mixed to obtain a toner having a specific concentration of 9.0% by weight.
Was prepared.

This two-component developer was subjected to normal temperature and normal humidity (20 ° C./50%) using a copying machine manufactured by Toshiba (trade name “ED-3240”).
Under RH), the fixing property and the smear property were examined, and the aggregation resistance (left standing at 50 ° C. for 8 hours) and the developer fluidity of the toner were examined. The results are shown in Table 2 below.

[0075]

[Table 2]

* 1 ○: No fixation in the crusher ×: Fixation in the crusher * 2 ○: Fixing rate of 75% or more ×: Fixing rate of less than 75% * 3 ○: Good smearing property ×: Poor smearing property * 4 ○ : 80 sec / 5 in JIS-Z2502
0 g or less ×: Exceeding the above standard * 5 ○: No aggregate after standing at 50 ° C. for 8 hours ×: With aggregate after standing at 50 ° C./8 hours As shown in Table 2, according to the present invention, In Examples 1 to 8, the fixation level, fixability, smear, fluidity,
Good results were obtained with both cohesion resistance. In Examples 9 to 11, the fixation level, fluidity and cohesion resistance were slightly inferior. This is based on the composition of the resin and the amount of wax added.
It is considered that extra wax (free wax) that could not be internally added was present in the resin, and the free wax was softened by the heat generated during the pulverization, causing some adhesion and fixation in the pulverizer. In addition, the fluidity and agglomeration resistance slightly deteriorated due to the presence of the free wax. However, the fixing property and the smearing property were excellent, and the level was practically no problem. On the other hand, Comparative Examples 1 to 4 were inadequate in all of the fixing level, fixing property, smearing property, fluidity and cohesion resistance, and were not practical levels.

[0077]

According to the present invention, good compatibility with the resin is achieved by adding (internally adding) a wax to the resin having a molecular weight distribution of at least two before mixing the colorant and the charge control agent. And it became possible to contain a sufficient amount more than before.

As described above, when the present invention is used, the wax can be sufficiently and uniformly dispersed in the toner particles, so that the amount of the free wax is reduced, and the toner adheres to the wall surface of the pulverizing chamber or the collision plate during the production. At the same time, the offset resistance, the fixing property, the smearing property, the fluidity, the aggregation resistance and the like are improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an image forming apparatus to which a developer of the present invention can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 2 ... Charging charger 3 ... Erasing array 4 ... Exposure part 5 ... Developing device 6 ... Transfer charger 7 ... Peeling charger 8 ... Cleaning device 9 ... Static elimination charger 10 ... Image forming means 11 ... Aligning roller pair 12 ... Guide Body 13: Conveyor belt

Claims (8)

[Claims] 1. A first binder resin having a first molecular weight, in which a coloring material, a first wax and a second wax different from the first wax are internally added during polymerization, and A developer, comprising: a wax and the second wax, which are internally added during polymerization, and a second binder resin having a second molecular weight higher than the first molecular weight. 2. A colorant, having a molecular weight of 1,000 to 30,0.
00 polypropylene wax and molecular weight 1,000-
A first binder resin having a molecular weight of 10,000 to 100,000, in which 10,000 polyethylene waxes are internally added during polymerization, the polypropylene wax and the polyethylene wax being internally added during polymerization, and
A second binder resin having a molecular weight of from 000 to 500,000. 3. A first binder resin having a first molecular weight in which a coloring material, a first wax and a second wax different from the first wax are internally added during polymerization, and A wax and the second wax are internally added during the polymerization, and a second binder resin having a second molecular weight higher than the first molecular weight, and the first wax and the second wax are internally added during the polymerization. And a third binder resin having a third molecular weight higher than the second molecular weight. 4. A coloring material and a molecular weight of 1,000 to 30,0.
00 polypropylene wax and molecular weight 1,000-
A first binder resin having a molecular weight of 10,000 to 100,000 in which 10,000 polyethylene waxes are internally added during polymerization, the polypropylene wax and the polyethylene wax being internally added during polymerization, and
A second binder resin having a molecular weight of 0000 to 250,000, the polypropylene wax and the polyethylene wax are internally added at the time of polymerization, and 100,0
A third binder resin having a molecular weight of from 00 to 500,000. 5. A colorant, having a molecular weight of 1,000 to 30,0.
00 polypropylene wax and molecular weight 1,000-
35 to 55% by weight of a first binder resin having a molecular weight of 10,000 to 100,000 in which 10,000 polyethylene waxes are internally added during polymerization, and the polypropylene wax and the polyethylene wax are internally added during polymerization, 50,000 to 250,000
0 to 20% by weight of a second binder resin having a molecular weight of 0, the polypropylene wax and the polyethylene wax are internally added at the time of polymerization, and 100,000 to 500,0.
Third binder resin 45 to 65 having a molecular weight of 00
%, And the polypropylene wax is included in an amount of 1.6 to 6.0% by weight based on the total amount of the binder resin, and the polyethylene wax is included in an amount of 0.1 to 2.0% by weight based on the total amount of the binder resin. Developer. 6. A first binder resin having a first molecular weight by performing polymerization using a solution containing a first wax, a second wax different from the first wax, and a first resin monomer. A first wax resin production step of producing a first wax, a first wax, a second wax different from the first wax and a solution containing a second resin monomer, the polymerization is carried out, A second binder resin manufacturing step of manufacturing a second binder resin having a second molecular weight larger than the molecular weight, and melt-kneading the mixture containing the first binder resin, the second binder resin, and the coloring material. A method for producing a developer, comprising: a melt-kneading step of obtaining a melt-kneaded material; and a toner particle producing step of pulverizing the melt-kneaded material to produce toner particles. 7. A polypropylene wax having a molecular weight of 1,000 to 30,000, a molecular weight of 1,000 to 10,000.
Of 100,000 to 100,000 using a solution containing polyethylene wax and a first resin monomer.
A first binder resin production process for producing a first binder resin having a molecular weight of 0, a polypropylene wax having a molecular weight of 1,000 to 30,000, a polyethylene wax having a molecular weight of 1,000 to 10,000, and a second resin A second binder resin production step of performing polymerization using a solution containing a monomer to produce a second binder resin having a molecular weight of 100,000 to 500,000; A melt kneading step of melt-kneading a mixture containing the binder resin and the colorant of the present invention to obtain a melt-kneaded material; and a toner particle manufacturing step of pulverizing the obtained melt-kneaded material to produce toner particles. A method for producing a developer, comprising: 8. A polypropylene wax having a molecular weight of 1,000 to 30,000 1.0 to 6.0% by weight,
000 to 10,000 polyethylene wax 0.1 to
Polymerization is carried out using a first mixture containing 2.0% by weight and a first resin monomer, and 10,000 to 100,000.
To produce a first binder resin having a molecular weight of
Of a binder resin, 1.0 to 6.0% by weight of a polypropylene wax having a molecular weight of 1,000 to 30,000, and a molecular weight of 1,000 to 1
Polymerization is carried out using a second mixture comprising 0.1 to 2.0% by weight of 0000 polyethylene wax and a second resin monomer, and a second mixture having a molecular weight of 50,000 to 250,000. A second binder resin manufacturing process for manufacturing a binder resin, 1.0 to 6.0% by weight of a polypropylene wax having a molecular weight of 1,000 to 30,000, and a molecular weight of 1,000 to 1
Polymerization is carried out using a third mixture comprising 0.1 to 2.0% by weight of 0000 polyethylene wax and a second resin monomer, and a third mixture having a molecular weight of 100,000 to 500,000. A second binder resin production step of producing a binder resin, wherein the first binder resin is 35 to 55% by weight and the second binder resin is 0 to 0% by weight based on the total amount of the binder resin.
A melt-kneading step of melt-kneading a mixture containing 20% by weight, 45 to 65% by weight of the third binder resin and a colorant, and obtaining a melt-kneaded product, and pulverizing the obtained melt-kneaded material, A method for producing a developer, comprising a toner particle producing step of producing toner particles.