JPH09146306A - Toner for electrophotography and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent electrification rising from an initial stage at the time of printing wear and to prevent toner scattering, surface staining and irregular transfer from occurring by setting a specified coagulating degree, the specified amount of electrification control agent on a toner surface and the specified content of the electrification control agent per toner pts.wt. SOLUTION: This toner for electrophotography is set so that its coagulating degree is 5-15%, the amount of the electrification control agent on the toner surface is >=2×10<-4> g/g and the contact of the electrification control agent to 100 pts.wt. of the toner is 0.01-5 pts.wt. Raw material to be pulverized is primarily crushed by a jet type crusher provided with compressed air and an impingement plate as principal component elements, and secondarily crushed by a rotor type crusher which is provided with a fixed container 4 functioning as an outer wall and a rotating piece 3 aligning its center axis 2 with the container 4 as the principal component elements, and the container 4 and the rotating piece 3 of which have a tapered part. Thus, a stable image is obtained from the initial stage at the time of printing. Especially, in the case of full color toner, the reproducibility of a color tone is excellent and the irregular transfer is prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in an image forming method for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, etc. From the above, an electrophotographic toner having excellent charge rising property, a stable charge level can be obtained, toner scattering does not occur, and a stable image density can be obtained without causing scumming in the image quality and transfer unevenness, and the same. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Generally, in an image forming method such as an electrophotographic method and an electrostatic photography method, a toner and a carrier are mixed by stirring in order to develop an electrostatic latent image formed on a latent image carrier. The resulting developer is used. The developer is required to be a suitably charged mixture. Generally, as a method for developing an electrostatic latent image, a method using a two-component developer obtained by mixing a toner and a carrier and a method using a one-component developer containing no carrier are known. The former developing method using a two-component type developer can obtain a relatively stable and good image, but has a drawback that carrier deterioration and variation in the mixing ratio of toner and carrier are likely to occur. On the other hand, the latter one-component developer does not have the disadvantage of the former, but has a disadvantage that the chargeability is hardly stabilized.

In recent years, the colorization of the electrophotographic system has been advanced, and demands for high image quality and high reproducibility have been increasing. As the toner for full-color electrophotography, toner colored yellow, magenta, and cyan is used. A black toner is also used as needed. Usually the toner is a binder resin,
Obtained by melting and kneading predetermined materials such as colorants (dye, pigment, magnetic substance, etc.), charge control agents, cooling and solidifying, and then classifying the finely ground material. It can be obtained by adding an additive (ultrafine particle colloidal silica or the like) in order to impart fluidity to the fine particle powder and stirring and mixing. There is also a method of producing a polymerized toner from a polymerized monomer by a polymerization method. As the polymerization method, a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, a seed polymerization method, and the like are known. In order to obtain a color image which is an electrophotographic process, such a color developer must have good spectral reflection characteristics without the diffused reflection of the fixed toner, and the superposed toner reproduces all color tones. Therefore, it is indispensable to have transparency and to maintain a charge amount level and fluidity that do not cause scumming of toner, uneven transfer in image quality, and reduction in image density in image quality. It is desirable that the particle size of the toner is also small in order to have higher resolution and image clarity.

In the general toner manufacturing method as described above, in the case of the collision type powdering method, the shape of the obtained particles is indefinite, and the particles are added to the powder particles in order to maintain the fluidity. Although the agent is added and the mixture is stirred and mixed, the toner obtained by this method has a drawback that the apparent index such as fluidity is improved but the characteristics of the toner base itself are not changed. Further, in the case of the polymerization method, the obtained particles have a spherical shape and are excellent in fluidity, but it is very difficult to uniformly disperse the coloring component in the toner particles by the method. Therefore,
When an image is obtained by an electrophotographic process, it causes a decrease in image density, background stains, and toner scattering. In particular, in the case of color toner, since yellow, magenta, and cyan are overlapped to reproduce the color tone, unless the coloring component is uniformly dispersed in the toner particles, the reproducibility of the color tone is significantly deteriorated. Several methods have been proposed for such conventional problems.

For example, in (I) Japanese Patent Laid-Open No. 3-171147, the surface dye concentration of the toner is 5 × 10 ⁻³ (g / g).
And a toner containing 0.01 to 5% by weight of a polar group-containing monomer for charge control having a polar group. However, the toner does not consider the fluidity that greatly contributes to triboelectrification, ideal triboelectrification cannot be performed, and the charge rising property is not satisfactory. In addition, (II) JP-B-7-9543 and JP-B-7-9544 propose polymerized toners produced by a suspension polymerization method for the purpose of improving substantially spherical fluidity. However, even by these proposals, particularly in the case of a dry toner having a small particle diameter containing a fine powder of 5 μm or less to some extent, it is not possible to obtain a sufficiently satisfactory nutching characteristic, or in order to obtain the dry toner. As a manufacturing method, there are problems in terms of productivity and cost such as requiring special manufacturing conditions or special manufacturing equipment.

Further, in (III) Japanese Examined Patent Publication No. 6-77161, heat treatment, jet milling, or collision-type powdering is performed until the ratio of the short diameter to the long diameter of the obtained powder particles becomes a specific ratio. A manufacturing method for fixing core material particles has been proposed. However, in the method,
The toner surface state is not taken into consideration, and the charge control agent on the surface may be detached, and the charge rising property is still unsatisfactory. Also, in order to obtain the core material particles that have been chamfered, the processing is performed by setting the refining ability to a low level.
A decrease in productivity is inevitable. Furthermore, (IV) JP-A-7-
Japanese Patent No. 181732 proposes a method of subjecting the toner base particles subjected to the powdering treatment to a spheroidizing treatment by a mechanical impact force. In this publication, spherical treatment is performed until the unevenness of the toner surface disappears, and the resulting charge control agent on the toner surface is desorbed, and the ideal charge rising characteristics are not obtained, which is disadvantageous in toner scattering and the like. . Also, although the Kryptron system is used as the spheronizing device, a classifying equipment is indispensable for performing an ideal sphere treatment using the system, which is disadvantageous in terms of manufacturing equipment and productivity.

Further, (V) Japanese Patent Application Laid-Open No. 7-181736 proposes a method in which a powdered raw material is ground by a collision type air stream powdering means and then surface modification is carried out using a low impact treatment device. In this publication, in consideration of production efficiency, a Kryptron system having no classification equipment is used. However, the surface condition of the toner obtained by this method is not satisfactory, and the ideal charging rise characteristics cannot be obtained. In any of the above proposals (I), (II), (III), (IV), and (V), neither the fluidity nor the amount of the charge control agent on the toner surface is satisfactory, and the charge rises. Sex is not satisfactory and is also disadvantageous in productivity.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and improves a matching property with a copy machine, and more particularly to a copy machine designed as a high image quality / color specification. It is intended to provide an electrophotographic toner capable of sufficiently improving the quality of the electrophotographic toner and maintaining or improving the productivity and cost at the same level as conventional ones.

That is, the first object of the present invention is that regardless of the particle size distribution of the toner itself or the specification conditions, the charge rising property is excellent from the initial stage of printing durability, toner scattering does not occur, and the image quality is low. It is an object of the present invention to provide an electrophotographic toner capable of obtaining a stable image density without causing stains or transfer unevenness. A second object of the present invention is to provide a manufacturing method for inexpensively manufacturing an electrophotographic toner that can obtain stable matching quality.

[0010]

The present inventor has conducted studies to solve the above-mentioned conventional problems, and as a result, by defining the degree of aggregation and the amount of charge control agent on the toner surface,
It was found that the charging rise was improved, and that toner scattering and transfer unevenness in image quality did not occur, and such toner was used in a jet-type dusting machine mainly composed of compressed air and a collision plate. After performing the primary powdering, the main container is a fixed container as an outer wall and a rotating piece having the central axis as an agreed value, and the fixed container and the rotating piece each have a tapered portion. It was found that it is manufactured by carrying out secondary refining with a rotor type refining machine provided. In this way, it was found that the electrophotographic toner having a good level of cohesion and the amount of charge control agent on the toner surface can be produced with high efficiency, and a satisfactory charge rise control can be obtained, and the present invention has been completed. . That is, according to the present invention, the following (1) to (5) are provided.

(1) In an electrophotographic toner containing at least a binder resin, a colorant, and a charge control agent as main components, the degree of aggregation is 5 to 15 (%) and the amount of the charge control agent on the toner surface is 2 × 10 ^{−. An} electrophotographic toner having a content of ⁴ (g / g) or more and a content of the charge control agent of 0.01 ^-5 parts by weight per 100 parts by weight of the toner. (2) The electrophotographic toner according to (1), wherein the binder resin is a polyol having an epoxy resin portion and an alkylene oxide portion in the main chain and an inactive resin terminal.

(3) The toner for electrophotography according to (1), wherein the volume average particle diameter of the toner is 9 μm or less. (4) A toner for electrophotography, which is a full-color developer composed of each toner for electrophotography according to (1), wherein the colorant is at least yellow, magenta, and cyan. (5) (a) After primary refining of the refining raw material with a jet-type refining machine equipped with compressed air and a collision plate as main components, (b) a fixed container as an outer wall and Performing secondary sizing with a rotor-type slicing machine having a fixed container and a rotating piece having a central axis as an agreed value as main components, and further comprising the fixed container and the rotating piece having a tapered portion. (1) The method for producing an electrophotographic toner according to (1).

According to the earnest studies by the present inventors, when the amount of the charging agent on the toner surface is low, frictional charging with the carrier is not performed promptly, and it becomes difficult to obtain a desired charging rising property. Therefore, when an image is obtained in the electrophotographic process, it causes scumming and toner scattering, and particularly in the case of full-color toner, since a plurality of colors such as yellow, magenta, and cyan are superimposed to reproduce the color tone,
The reproducibility of the color tone becomes extremely poor. Further, when the cohesion degree exceeds 15 (%), that is, when the spheroidizing treatment is not performed, the desired charge rising property is not obtained, and the image density is lowered, and the toner replenishability is lowered. become. Further, when the toner has an aggregation degree of less than 5 (%), that is, when the sphericity is too high, the charge control agent on the toner surface is released, and the desired charge rising property cannot be obtained. Further, when the content of the charge control agent is more than 5 parts by weight per 100 parts by weight of the toner, a decrease in image density and a decrease in moisture resistance are observed. Content of charge control agent is 0.0
If the amount is less than 1 part by weight, a desired amount of charge cannot be obtained, which also causes scumming. That is, the toner of the present invention has an aggregation degree of 5 to 15 (%), and the amount of the charge control agent on the toner surface is 2 × 10 ⁻⁴ (g / g) or more. On the other hand, it became clear that the content of the charge control agent needs to be 0.01 to 5 parts by weight.

Further, in the present invention, by using a polyol resin having an epoxy resin end capped on the binder resin and having a polyoxyalkylene portion in the main chain, environmental stability, stable fixing characteristics, and copying can be achieved. This is designed to prevent the transfer of the toner image to the sheet when it is adhered to the vinyl chloride resin sheet on the fixed image side, especially when used for full-color toner, color reproducibility, stable gloss, and curl of copy-fixed image. Effective for prevention. Also,
When the volume average particle diameter of the toner is large, the resolution and the sharpness of the image are deteriorated in the image quality. Therefore, the toner of the present invention desirably has a volume average particle diameter of 9 μm or less. In particular, in the case of a toner having a small particle size such as an irritant toner, since the fluidity as a powder property is likely to be lowered, the effect of improving the quality of the matching property is remarkable in the present invention. Further, in the full-color toner as well, the fluidity and charge rising property of the powder characteristics directly affect the image quality such as the color reproducibility, so that the quality improving effect of the matching characteristics according to the present invention is more remarkable.

In the present invention, the degree of aggregation is 5 to 15 (%), and the amount of the charge control agent on the toner surface is 2 × 10 ^-4 (g / g).
g) In order to obtain the toner of the above, (a) after performing the primary screening of the screening raw material with a jet-type grinding machine equipped with compressed air and a collision plate as main components, (b) ) A secondary powder in a rotor-type grinding machine in which a fixed container as an outer wall and a rotating piece having the same central axis as the fixed container are the main constituent elements, and the fixed container and the rotating piece are provided with a tapered portion. Good results can be obtained relatively easily by the manufacturing method which is smart. The measuring method of the aggregation degree of the present invention is performed using a powder tester. That is, open 2.0 g of toner 1
When passing through a 50 μm, 75 μm, 45 μm sieve,
The amount of residual toner on each screen was measured and calculated using the formula shown below.

Cohesion degree = (A + 0.6 × B + 0.2C) /
2.0 × 100 A: Toner remaining amount (g) on a sieve having an opening of 150 μm B: Toner remaining amount (g) on a sieve having an opening of 75 μm C: Toner remaining amount (g) on a sieve having an opening of 45 μm The method for measuring the amount of the charge control agent on the toner surface in the present invention is as follows. 50 ml for 100 mg of toner
Of methanol was added, and the mixture was stirred for 10 minutes in a ball mill and allowed to stand for one day. The supernatant concentration was measured by an absorptiometer and calculated according to the Lambert-Beer law. The amount of the charge control agent on the toner surface means a value converted into the amount of the charge control agent per 1 g of the toner.

The charge rising property in the present invention is the charge amount Q obtained when the toner is mixed with the carrier by stirring for 10 minutes.
When the charge amount is Q2 when the mixture is stirred and mixed for 20 seconds with respect to 1, it is calculated using the formula of (Q2 / Q1) × 100 (%). Further, the respective charge amounts Q1 and Q2 can be measured by the suction type Faraday gauge method. The particle size distribution of the toner can be measured by various methods, but in the present invention, the small hole passage method (Coulter counter method) was used. Coulter counter TAII (manufactured by Coulter) as a measuring device
Using 1% saline and an aperture of 10
It was measured as μm.

The toner used in the present invention is composed of at least a binder resin, a colorant, and a charge control agent. As the binder resin, all those conventionally used as the binder resin for toner are applied. Specifically, polystyrene, polychlorostyrene, homopolymers of styrene such as polyvinyltoluene, and substituted products thereof; styrene / p-chlorostyrene copolymers, styrene / propylene copolymers, styrene / vinyltoluene copolymers, styrene / vinyl. Naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / methyl methacrylate copolymer, Styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / vinyl ethyl ether copolymer, styrene / vinyl methyl ketone copolymer, styrene / butadiene copolymer Polymer, styrene / Styrene-based copolymers such as soprene copolymers, styrene / acrylonitonyl / indene copolymers, styrene / maleic acid copolymers, styrene / maleic acid copolymers, styrene / maleic acid ester copolymers; polymethyl tacrylate , Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyol, polyvinyl butyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aliphatic hydrocarbon resin, aromatic system Examples include petroleum resin, chlorinated paraffin, and paraffin wax, which may be used alone or in combination of two or more kinds.

In particular, as the binder resin, it is preferable to use a polyol having an epoxy resin part and an alkylene oxide part in the main chain and having an inactive resin terminal. Further, the epoxy resin constituting the polyol is at least two kinds of bisphenol A type epoxy resins having different number average molecular weights, and the low molecular weight component has a number average molecular weight of 360.
~ 2000, the number average molecular weight of the high molecular weight component is 30
It is preferably from 00 to 10,000. Further, the low molecular weight component is 20 to 50 wt% and the high molecular weight component is 5 to 40 w.
It is preferably t%. When the amount of the low molecular weight component is too large or the molecular weight is lower than 360, the gloss may be excessive and the storage stability may be deteriorated. Further, when the amount of the high molecular weight component is too large or when the molecular weight is higher than 10,000, the gloss may be insufficient and the fixability may be deteriorated.

As the colorant, all the pigments and dyes that have been used as colorants for toners can be applied. Specifically, carbon black, rank black, iron black, ultramarine, nigrosine dye, aniline blue, chalco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C lake, chrome. Examples include yellow, quinacridone, benzidine yellow, malachite green, malachite green hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, trisazo dyes and pigments.

Further, it is effective to blend a charge control agent in order to control the polarity of the toner. As the charge control agent in this case, a conventionally known charge control agent can be used.
Examples thereof include nigrosine dyes, quaternary ammonium salts, amino group-containing polymers, metal-containing azo dyes, salicylic acid metal complex compounds, and phenol compounds. Further, in the toner used in the present invention, in order to impart releasability, in addition to synthetic waxes such as low molecular weight polypropylene and polyethylene, candelilla wax, carnauba wax, rice wax, wood wax, jojoba Vegetable-based waxes such as oils; Animal-based waxes such as beeswax, lanolin and spermaceti; Mineral waxes such as montan wax and ozokerite; Fat-based waxes such as hydrogenated castor oil, hydroxystearic acid, fatty acid amides and phenol fatty acid esters It may also contain a class.

In addition to the above charge control agent and release agent, various plasticizers (dibutyl phthalate, dioctyl phthalate, etc.) for the purpose of adjusting the thermal properties, electrical properties, and physical properties of the toner as necessary. It is also possible to add auxiliary agents such as resistance adjusting agents (tin oxide, lead oxide, antimony oxide, etc.). Further, if necessary, additives other than the above charge control agent, release agent, auxiliary agent, etc. can be mixed. Examples of the additive include a flow imparting member such as colloidal silica, titanium oxide, and aluminum oxide. The flow imparting member can be appropriately selected from those having a primary particle size of 0.001 to 1 μm, preferably 0.005 to 0.1 μm, and fluorine-containing hydrophobized silica is particularly preferable and usually 0 It is mixed and used in a ratio of 2 to 5% by weight.

The collision type crusher used in the manufacturing method of the present invention includes, for example, a hammer mill, a ball mill, a tube mill, a vibration mill and the like, which are provided with compressed air and a collision plate as main constituent elements. As the jet type pulverizer formed as described above, 1 type and IDS type collision plate type pulverizers (manufactured by Nippon Pneumatic Industry Co., Ltd.) can be preferably used. Also, as a grinding type crusher, a roll mill, a pin mill,
A fluidized bed type jet mill and the like can be exemplified, but in particular, a turbo mill (Turbo Kogyo Co., Ltd.) is used as a rotor type pulverizer including a fixed container as an outer wall and a rotating piece having the same central axis as the fixed container as main components. ), Kryptron (produced by Kawasaki Heavy Industries, Ltd.), Fine Mill (produced by Nippon Pneumatic Industry Co., Ltd.) and the like can be used.

The residence time in the rotor type pulverizer is a factor for controlling the cohesion degree and the amount of the charge control agent on the toner surface in the present invention to a preferable level. For example, in a Kryptron system not equipped with a classifier, jet-type crushed products do not stay in the rotor-type crusher, and the crushed colored particles are sent to the next step. The particles do not have a satisfactory level of aggregation and tend to be inferior in fluidity, and the shape of the particles is almost the same as that of the jet pulverized product. Further, when the residence time in the rotor type pulverizer is too long, that is, when the amount of the particles returned from the classifier to the pulverizer is increased, the spheroidization tends to proceed and the fluidity increases, but the toner The charge control agent on the surface has been desorbed,
After all, we cannot get a satisfactory level. It is also disadvantageous in terms of cleaning property. If the return amount of the crushed object becomes extremely large, the load on the crushing device will increase and the crushing device will melt.

Particularly in the present invention, it is preferable to use a fine mill as the rotor type crusher. In this device, the fixed container and the rotating piece have tapered portions,
By rotating the rotary piece at a high speed, a swirling flow is generated and a classifying action works at the same time as the pulverization, and efficient processing is possible, and therefore, it is not necessary to provide a classifying device which is required in the Kryptron system. Further, since the fixed container and the rotating piece in the apparatus are horizontally placed as shown in FIG. 1, both the fixed container and the rotating piece can be attached / detached, and the fixed container, the gap adjustment between the rotating pieces, and the fixed container having different groove shapes. It is also easy to use the rotating piece. The fine mill system is more advantageous than the Kryptron system in terms of maintainability, equipment space, and cost. FIG. 1 shows a schematic view of a rotor type crusher in which a fixed container and a rotating piece have tapered portions. In the figure, 1 is an entrance, 2 is a rotating shaft,
3 is a rotating piece, 4 is a fixed container, and 5 is an outlet. In addition, it is possible to control the processing temperature by sending cold air together with the object to be crushed, if necessary.

In the present invention, when the additive and the pulverized colored particles are mixed and treated, a conventionally known V blender,
It can be appropriately selected and used from a container rotating type such as a ball mill, a container fixed type such as a ribbon mixer, a paddle mixer, a Henschel mixer, and a super mixer, and a composite type thereof. The electrophotographic toner obtained by the manufacturing method of the present invention can be used for image formation by a typical developing device useful in the image forming method shown in FIG. FIG. 1 shows its outline. In FIG. 1, the toner filled in the toner tank 6 is supplied to the developing device 8 by the rotation of the supply blade 7. On the other hand, the toner supplied to the developing device is agitated and mixed by the agitating blade 9 in the developing device in order to make the toner concentration of the developer uniform, and the toner is charged. The developer is applied to the developing roller 1 by the elastic blade 10.
It is evenly deposited on 1. Further, the electrostatic latent image is developed by applying a DC bias voltage to the developing roller with respect to the electrostatic latent image having a charge of the opposite polarity to that of the toner on the latent image holder (photosensitive drum) 12. You can

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. The parts here are based on weight. Example of polyol synthesis In a separable flask equipped with a stirrer, thermometer, N ₂ inlet, and condenser, 378.4 g of a low-molecular bisphenol A type epoxy resin (number average molecular weight: about 360) and a high molecular bisphenol A type epoxy resin (number (Average molecular weight: about 2700)
86.0 g, bisphenol A-type propylene oxide adduct diglycidyl compound [n + m in the following general formula (1): about 2.1] 191.0 g, bisphenol F2
74.5 g, 70.1 g of p-cumylphenol, and 200 g of xylene were added. In an N ₂ atmosphere, the temperature was raised to 70 to 100 ° C., 0.183 g of lithium chloride was added, the temperature was further raised to 160 ° C., and xylene was distilled off under reduced pressure.
Polymerization is carried out at a reaction temperature of ℃ for 6 to 9 hours to give a softening point of 109.
1000 g of polyol resin having a Tg of 58 ° C. was obtained.

[0028]

Embedded image

(Where R is

[0030]

Embedded image

Example 1 Binder resin Polyol resin 77 parts Release agent Low molecular weight polypropylene 10 parts Coloring agent Carbon black 10 parts Charge control agent Zinc salicylate 3 parts A mixture having a composition of 3 parts is melt-kneaded by using a biaxial kneader. I went. The kneaded product has a volume average particle size of 1 with an IDS-2 type jet crusher (manufactured by Nippon Pneumatic Mfg. Co., Ltd.).
Finely pulverized to 0.5 μm, and the finely pulverized product was pulverized by a fine mill FM-300S type rotor pulverizer to have a volume average particle diameter of 9.5 μm, and further into an air stream classifier. And finely classify, and the volume average particle size is 10.0μ
m fine particles were obtained. To 100 parts of the fine particles, 0.3 part of fluorinated silane surface-treated silica was added and mixed with a Henschel mixer to obtain an electrophotographic toner.

Example 2 The same kneaded product as in Example 1 was finely pulverized by an IDS-2 type jet pulverizer so that the volume average particle diameter was 10.5 μm, and the fine pulverized product was Fine Mill FM-300S. A rotor type pulverizer was used to pulverize the powder so that the volume average particle diameter was 7.5 μm, and the air flow type pulverizer was used to classify fine powder to obtain fine particles having a volume average particle diameter of 8.0 μm. As in Example 1, 0.3 part of fluorinated silane surface-treated silica was added to 100 parts of the fine particles and mixed to obtain an electrophotographic toner of Example 2.

Comparative Example 1 The same kneaded material as in Example 1 was finely pulverized with an IDS-2 type jet pulverizer so as to have a volume average particle diameter of 9.5 μm,
The finely pulverized product was finely classified by an air stream classifier to obtain fine particles having a volume average particle size of 10.0 μm. As in Example 1, 0.3 parts of fluorinated silane surface-treated silica was added to and mixed with the fine particles to obtain an electrophotographic toner of Comparative Example 1.

Comparative Example 2 The same kneaded material as in Example 1 was finely pulverized by an IDS-2 type jet pulverizer so that the volume average particle diameter was 7.5 μm,
The finely pulverized product was finely classified by an airflow classifier to obtain fine particles having a volume average particle size of 8.0 μm. As in Example 1, 0.3 parts of fluorinated silane surface-treated silica was added to the fine particles and mixed to obtain an electrophotographic toner of Comparative Example 2.

Comparative Example 3 The same kneaded material as in Example 1 was pulverized by a fine mill FM-300S type rotor pulverizer so as to have a volume average particle size of 9.5 μm, and further finely pulverized by an air stream classifier. The particles were classified to obtain fine particles having a volume average particle diameter of 10.0 μm. In the same manner as in Example 1, 0.3 part of fluorine-containing silane surface-treated silica was added to and mixed with the fine particles to obtain an electrophotographic toner of Comparative Example 3.

Comparative Example 4 The same kneaded material as in Example 1 was pulverized by a fine mill FM-300S type rotor pulverizer so as to have a volume average particle size of 7.5 μm, and further finely pulverized by an air stream classifier. The particles were classified to obtain fine particles having a volume average particle diameter of 8.0 μm. In the same manner as in Example 1, 0.3 part of fluorine-containing silane surface-treated silica was added to and mixed with the fine particles to obtain an electrophotographic toner of Comparative Example 4. Using the electrophotographic toners obtained in Examples 1 and 2 and Comparative Examples 1 to 4, image evaluation and durability test were performed with a toner copying machine FT2720. Table 1 shows the results.

[0037]

[Table 1]

Productivity ◎: Particularly high ○: Normal Δ: Slightly inferior ×: Practical image quality evaluation ◎: Particularly excellent ○: Good Δ: Slightly bad ×: Poor Example 3 Binder resin Polyol resin 83. 5 parts Release agent Low molecular weight polypropylene 10 parts Colorant C.I. I. Pigment Yellow 17 3.8 parts Charge control agent Zinc salicylate A mixture having a composition of 3 parts was melt-kneaded using a biaxial kneader. The volume average particle size of the volume average kneaded product was 1 using an IDS-2 type jet mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.).
Finely pulverized to a size of 0.5 μm, and the finely pulverized product was pulverized by a fine mill FM-300S type rotor pulverizer to a volume average particle size of 7.5 μm, and further into an air stream type classifier. Fine powder classification was performed to obtain fine particles having a volume average particle diameter of 8.0 μm. 0.3 part of fluorine-containing silane surface-treated silica was added to 100 parts of the fine particles and mixed with a Henschel mixer to obtain a yellow toner for electrophotography of Example 4.

Next, C. I. Pigment Yellow 17 was used in place of 3.5 parts of Rhodamine pigment to obtain magenta toner for electrophotography. Then C.I. I. Cyan toner for electrophotography was obtained by using 3.5 parts of phthalocyanine pigment instead of Pigment Yellow 17.

Comparative Example 5 The same kneaded material as in Example 3 was finely pulverized by an IDS-2 type jet pulverizer so as to have a volume average particle diameter of 9.5 μm,
The finely pulverized product was finely classified by an airflow classifier to obtain fine particles of yellow, magenta and cyan having a volume average particle diameter of 10.0 μm. In the same manner as in Example 4, 0.3 part of fluorine-containing silane surface-treated silica was added to and mixed with each of the fine particles to obtain an electrophotographic toner of Comparative Example 4.

Comparative Example 6 The same kneaded material as in Example 3 was pulverized by a fine mill FM-300S type rotor pulverizer so that the volume average particle diameter was 9.5 μm, and the pulverized material was classified by air flow type. Fine particles were classified by a machine to obtain yellow, magenta, and cyan fine particles having a volume average particle diameter of 10.0 μm. In the same manner as in Example 4, 0.3 part of fluorine-containing silane surface-treated silica was added to and mixed with each of the fine particles to obtain an electrophotographic toner of Comparative Example 4. Using the electrophotographic toners obtained in Example 3 and Comparative Examples 5 and 6, a copying machine PRE manufactured by Ricoh Co., Ltd. was used.
Image evaluation and durability test were performed by TER550.
Table 1 shows the results. According to this, in Example 4, an image excellent in resolution, gradation and color reproducibility was obtained from the initial stage of printing durability without uneven transfer, and a stable image was obtained even after printing 100,000 sheets, Neither deterioration of the developer Q / M nor occurrence of toner scattering was observed. Moreover, in Comparative Example 4,
The image had very poor resolution and color reproducibility from the initial stage of printing durability, the developer Q / M dropped significantly after printing 100,000 sheets, and the toner scattering was also at a very poor level.

[0042]

As is apparent from the above description, according to the method for producing an electrophotographic toner of the present invention, (a) a jet type crusher comprising compressed air and a collision plate as main constituent elements. After the primary pulverization of the pulverized raw material at (b)
Secondary crushing with a rotor type crusher having a fixed container as an outer wall and a rotating piece having the same central axis as the fixed container as main constituent elements, and the fixed container and the rotating piece having a tapered portion. The toner obtained by the above-mentioned manufacturing method has a cohesion degree of 5 to 15 (%) and a charge control agent amount on the toner surface of 2 × 10 ⁻⁴ (g / g) or more. They are satisfied and have excellent charge rising characteristics.

As a result, a stable image can be obtained from the beginning of printing. In particular, a full-color toner is excellent in color tone reproducibility and does not cause transfer unevenness. Q / M of developer
Is stable even when a considerable number of images are obtained, and toner scattering and cleaning failure do not occur. Further, by using a polyol resin having an epoxy resin part and an alkylene oxide part in the main chain as the binder resin and having an inactive resin end, the volume average particle diameter is set to 9 μm or less, whereby fixability and storage property are improved. It is excellent in the property, the resolution is further improved, and a clear image can be obtained.

[Brief description of the drawings]

FIG. 1 shows a schematic explanatory view of a rotor type crushing device used in the present invention,

FIG. 2 shows a schematic illustration of a developing apparatus for developing a full color electronic photograph useful in the practice of the present invention.

[Explanation of symbols]

 1 inlet 2 rotating shaft 3 rotating piece 4 fixed container 5 outlet 6 toner tank 7 supply blade 8 developing device 9 developing device stirring blade 10 elastic blade 11 developing roller 12 latent image carrier (photosensitive drum)

Front page continuation (72) Inventor Hiroshi Yaguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hiroyuki Fushimi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Satomi Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd.

Claims (5)

[Claims] 1. An electrophotographic toner containing a binder resin, a colorant, and a charge control agent as main components, having an aggregation degree of 5 to 15 (%) and a charge control agent amount of 2 on the toner surface.
A toner for electrophotography, which has a content of the charge control agent of 0.01 to 5 parts by weight per 100 parts by weight of the toner, having a content of × 10 ^-4 (g / g) or more. 2. The toner for electrophotography according to claim 1, wherein the binder resin is a polyol having an epoxy resin portion and an alkylene oxide portion in the main chain and an inactive resin terminal. 3. The toner for electrophotography according to claim 1, wherein the volume average particle diameter of the toner is 9 μm or less. 4. A toner for electrophotography, wherein the colorant is at least yellow, magenta, and cyan, which is a full-color developer composed of each toner for electrophotography. 5. (a) After one crushing of the crushing raw material is carried out by a jet-type crushing machine equipped with compressed air and a collision plate as main constituent elements, (b) a fixed container as an outer wall Secondary rotation is carried out by a rotor type grinding machine which has a fixed container and a rotating piece having the same central axis as main constituent elements, and the fixed container and the rotating piece further include a tapered portion. The method for producing an electrophotographic toner according to claim 1, wherein