JPH04506420A - Dry electrostatic recording toner composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Dry electrostatic recording toner composition The present invention provides fusible electrostatically attractive toner particles suitable for developing electrostatic charge patterns. Electrography and electrophotographic reproduction and printing of toner compositions comprising In the technique of It is often desirable to form an electrostatic latent image on a photoconductive member that corresponds to digitized data. Are known. In another imaging method, an electrostatic latent image is imaged with a needle directed at a dielectric substrate. Therefore, it is formed by discharging. For example European Patent Application No. 0243 Zero printing methods, such as those described in No. 934, imagewise expose a photopolymer substrate. Light, charged on a conductive support, toned with dry or wet toner, and transferred to another substrate including doing.

An electrostatic latent image is a liquid developed image consisting of a colloidal system of charged colloidal particles in an insulating liquid. It can be developed using a chemical agent. In most cases, the latent image is formed by a finely divided developer material or toner. It is developed to form a powder image, which is then transferred onto a support sheet such as paper. Ru. The support sheet carrying the toner powder image is then passed through a fusing device and then finally The final copy is discharged in a printing machine corresponding to a copier as a corresponding final print.

General electrostatographic processes As is clear from the above overview of s), two essential steps have to be considered.

First, a latent electrostatically recorded image Ct is formed on a suitable member, such as a photoconductive drum.

Second, this latent image is developed into a visually recognizable vine image and then transferred to a transfer station for final hardening. transferred to a copy.

One of the objectives mentioned above for general electronic recording methods is to have the best possible quality. The final copy consists in providing an image on the corresponding final print.

“Quality” in electronic recording refers to the true faithful reproduction of the original to be reproduced, or the It is commonly understood as a faithful visual print of a vine image used in childcare.

Quality therefore depends on the uniform darkness of the image area, the background quality, the sharpness of the lines, and the overall image quality. This includes features such as high resolution.

In opto-electronic printing equipment, the quality, especially the resolution of latent electrostatic recording images, depends on each of the following steps. Depends on the accuracy of the image: The second is the conversion of the digitized data to be filled in, and the second is the conversion of the digitized data to be filled in. The third is the illumination of the photoconductive drum on the photoconductive drum. It is the resolution of the process. In the case of zero printing equipment, the quality of the latent electrostatic image depends on contact exposure. Determined by the light process.

In reproduction machines, the quality of the latent electrostatically recorded image is determined by the photoconductive drive produced by an electro-optical device. Much depends on the accuracy of the illumination of the ram and therefore the mirrors, lenses and optical fibers used. The optical qualities such as vinegar.

The Local Press Ltd, London, published 1975, R,M , 5 Chaffert, Electrophotography Expanded Revised Edition , page 93, 2, 15, 8 Re5 solution. of latent electrostatic images on xerographic plates such as amorphous selenium plates. Resolution is inherently very high due to the essentially particle-free nature of photoconductive films. stomach. The same is true for molecular organic photoconductive materials.

Furthermore, the first step in the overall electrostatic recording process, i.e. the illumination of the photoconductive drum, If the necessary care is taken in the configuration of the There are no limiting factors on the overall resolution obtained for the rough print.

Illumination for the photoconductive drum and the photoconductive drum itself require general electrostatic recording techniques. There is nothing to limit the resolution of the final print or copy that results from the overall preparation. The critical factor for quality is the second step of electrophotography, the visual identification. It is in the process of converting a latent image into an image.

Latent electrostatic images formed by either electronic printing or copying equipment cannot be visually identified. The overall accuracy of the developed copy depends primarily on the characteristics of the developer used. It is decided.

One of the characteristics that has traditionally been primarily concerned is the particle size and particle size distribution of the developer particles used. Yes, when using a two-component developer material, the particle size and It is known that there is a large particle size distribution.

Published by ATR Corporation, El Dorado, California, USA Literature, Effect of Taner 5hape on Image Qua In particular, the toner particle diameter and shape influence the quality of high-resolution quality. The sound is being tested.

Regarding the developer that should be used in high-resolution laser beam printers, toner particle size on the image and shape effects were tested experimentally. As a result, the shape of the toner and its charge distribution Apart from this, it has been revealed that fine particles are the most effective in providing high resolution. .

This fact, which is known in itself, is important for the production of fine toner particles and especially for the particle size. Several advanced techniques are proposed for toner particles with well-defined edge-conforming distribution. I made him do it.

U.S. Patent No. 3,942,979 (assigned to Xerox Corporation) ), less than about 30% of the number of toner particles have an average particle diameter of less than about 5μ; about 25% of the number of particles have a diameter between about 8μ and about 12μ, and the number of toner particles have a particle size distribution such that less than about 5% of the particles have an average particle diameter greater than about 20μ A toner material is claimed.

According to a preferred embodiment of the invention described in said patent, the number of toner particles is Less than about 10% have an average particle diameter of less than about 5μ, and about 60% of the number of toner particles having an average particle diameter between about 8 and about 12 microns, with less than about 5% of the toner particles having an average particle diameter of about 2 microns; It has an average particle diameter greater than 0μ.

U.S. Patent No. 4,284,701 (assigned to IBM Corporation) ), less than 15% by weight is greater than 16μ, and 7 to 15% by weight is less than 5μ. particle size distribution with a remainder of 5 to 16μ and a median particle size by weight of 8 to 12 Toner particles are claimed.

The resolution of electrostatic printing is determined by the average toner particle size distribution, independent of the particle size distribution of the toner particles. It is generally known that particle size and median particle size determine Efforts have been made to produce and use suitable developer materials.

However, the smaller the average particle size of the toner particles, or the overall toner The larger the very small toner particles in the toner and the overall The tendency of the image composition to agglomerate or cluster together is increased. Therefore dry electrostatic The limited flow properties of toners limit the use of very fine toner particles. This is a major factor. Therefore, high resolution is set as a sales requirement for each electrophotographic method. When necessary, liquid developer compositions are often used.

In fact, in order to produce very high-resolution electrostatic prints, average grains as fine as 0.25 μm are used. Liquid developer compositions having toner particles having a particle size or median particle size are known. Ru. Those skilled in the art will appreciate that agglomeration can be prevented by optimizing colloidal forces. electrostatic charge Liquid developer compositions suitable for use in developing patterns include e.g. National Patent No. 4123374 and No. 4138351 (both Belgian, Mortse) (transferred to Agfa Kevuelt N.V.).

However, liquid developers present significant drawbacks: they are carried along with the toner, The dielectric solvent that adheres to the electrographic print is evaporated and subsequently recycled or released into the atmosphere. It must be discarded to obtain a dry final print.

Compared to dry electrostatography, electrostatic recording devices that use liquid developers necessarily consume less It causes great inconvenience to the person.

Therefore, despite the limited flow properties of very fine dry electrostatic toner particles, Efforts have been made to produce such fine toners.

British Patent No. 111GB2180948 uses toner particles with a particle size of 5μ or less is listed. The use of such small toner particles results in an image resolution of 10 lines. /mm, while when the toner particle size is about 10μ, 5 lines/mm It is. To avoid sticking of toner particles to the image bearing member, a lubricant, e.g. Zinc acid should be added in an amount of at least 0.5% by weight.

European Patent Application No. 0255716 discloses a fine toner with uniform spherical particles. According to the said patent application, in which a method for producing particles is described, Coulter Counter The volume average particle size according to the Coulter Counter method is 1.0~7゜0. μ, and the number average flow rate is 1.0 to 5.0 μ.

The toner particles are composite suspension polymerized to provide improved flowability and charging properties. U.S. Pat. No. 4,737,433, manufactured by the method of An electrostatic recording method is described that uses toner particles having . According to this patent , an average diameter of less than lOμ from the image bearing member to the paper support at the electronic recording transfer station. We note that significant difficulties arise when attempting to transfer toner particles having Appropriate countermeasures have been proposed.

Japanese Patent Application No. 192711/1986 describes a sharp camera with excellent resolution using electrophotography. The formation of images according to which toner particles with a particle size of 1 to 5 μm is used. is used. Development of the latent image on the photoconductive drum consists of a photoconductive drum and a thin developer. This is done without contact between the layer application means.

It is therefore an object of the present invention to improve the overall quality of the final electrographic print and the quality of the electrographic process. Dry development that outperforms prior art dry developer materials due to its overall performance The purpose of this invention is to provide materials for cleaning agents.

The inventors believe that the purpose is to: (I) 90% by volume or more of the toner particles are larger than 0.5μ and smaller than 7μ; particle size diameter, with (■) about 50% or more by volume of the toner particles having the same particle size of less than about 5μ; It has a diameter.

containing classified toner materials having a particle size distribution, wherein said toner additives a flow-enhancing additive at a concentration of at least 0.1% and at most 5% by weight on the surface. The flow-enhancing additive has the following properties: AxB>10000 The characteristic is the product of the specific surface area (Am”/g) that satisfies the methanol value (B% volume). As will be explained later, the apparent ratio of the density to the bulk density of the toner particles is By providing an electrophotographic toner material that satisfies the following formula, achieved.

According to a preferred embodiment of the present invention, at least 90% by volume of the toner particles are smaller than 0.5μ. have an equal particle size diameter larger than 6 μm and less than 6μ, and more than about 50% by volume of the toner particles. The top has an equal particle size diameter of less than about 4μ.

According to a further preferred embodiment, at least 90% by volume of the toner particles are larger than 0.5μ. and have the same particle size diameter of less than 5μ, with about 50% by volume or more of the toner particles being about 3μ with the same particle size diameter less than or equal to

According to a further preferred embodiment, the toner particles are mixed with flow-enhancing additives. , which is coated with hydrophobic group-containing units giving rise to methanol values greater than 2o. ing.

In a further preferred embodiment, the mixed Contains toner with flow enhancer.

Toner compositions suitable for use in accordance with the present invention include several known toner blends and It should be manufactured by selecting and modifying the milling method. generally known The toner is made by successively mixing each component in a dissolved state, and after cooling, It is made by crushing a compound and turning it into a fine powder. Toner particles corresponding to the planned particle size are then A suitable particle classification method is used to obtain . Typical classification methods include air classification and sieving. Minute statement 14-506420 (4) Including set.

A preferred method of obtaining very fine toner particles of the present invention is by centrifugal air classification.

Suitable pulverization and air classification include A. as an air classification means.

T, P, (Alpine Turboplex windsichter) Ip50G, S.

A, F, G, (Alpine Fliessb) as fine grinding means, equipped with Combination devices such as eth-Gegenstrahlmuehle) type 100 obtained when using These devices are located in Cheshire, Runcorn and Livvy, UK. Alpine Professional at Ng Road, White House, and Industrial Nistate Available from Seth Technology Limited. Furthermore, air classification is possible with additional classification equipment. AlooMZR (Alpine Multiplex Labor Z This can be realized using ick-zack 5ichter). This device is also Alpa The thus obtained The particle size distribution of toner particles is Available from Coulter Electrox Corporation, Le Drive. Normal method using Coulter Counter Type TA II/PCAI It can be measured by

In air classifiers, air or other gases are used as the transport medium, and The particles contained in the medium are subject to two opposing forces: a traction force directed inside the medium and a Defined particle size, i.e. cut size, of zero particles exposed to centrifugal force directed towards the outside of the particle Therefore, both forces are in equilibrium. Large (heavy) particles are driven by mass-dependent centrifugal force. small (light) particles are dominated by a frictional force proportional to the particle diameter .

Larger or heavier particles will therefore fly outward as coarse particles, while smaller or heavier particles will fly outward as coarse particles. The lighter particles are carried inward by the air as a fine fraction. cut size The parameters are usually geometrical and operating parameters (size of class, rotor, speed of rotation). degree, etc.). The cut size depends on the changes in the parameters mentioned above. It can be done by

By applying the manufacturing method described above, the toner particles can be produced as claimed and as described above. Although toner particles that follow a particle size distribution can be produced, these toner particles are Until recently, their fluidity and overall performance in the electrostatic recording methods presented here were inadequate. This is sufficient to present problems when used in electronic copying or printing devices.

The inventors have achieved this by adding a suitable flow improver in a selected manner. The fluidity of toner particles obtained by obtaining toner particles suitable for use in electrostatic recording devices is We have found that it is possible to sufficiently enhance the

To improve the flow properties of toner, it is advisable to mix toner particles with flow-enhancing additives. These additives are primarily extremely finely divided inorganic or organic materials. This point The commonly used materials are silica, alumina or zirconium oxide or titanium oxide. It is a humid inorganic substance like tan. As a flow improver for toner compositions The use of silica is described in US Pat. No. 1,438,110.

The fumed silica particles used in the toner compositions of the present invention are essentially spherical; The reaction between various types and volumes of silane and the silanol groups of silica-based microparticles It has a surface covered with a hydrophobic layer such as that obtained by Regarding this, please refer to the See European Patent No. 0234009 of the Ricone Company. other Microparticles can also be used and exhibit comparable properties and manufacturing methods.

The type of surface can be varied and the degree of coverage can also be varied. chemically If a reacted coating is preferred, physically adsorbed coatings also meet the conditions of the invention. However, when processed over a long period of time, the film may form on the image bearing member and other mechanical parts. surface area greater than 150 m"7g and methane greater than 20 The fumed silica particles with a Gussa Corporation and Cabot Corporation, Boston, Massachusetts, USA. , marketed by Oxide Division under the trade names Aerosil and and CAB-0-SIL are available on the market. Aerosil R972 is 1io of fumed hydrophobic silica with a specific surface area of n”/g and a methanol value of 40. This is a typical example.

The specific surface area is calculated from Analytical Chemistry Vol. 30, No. 8 (1958 ), pp. 1387-1390, Determination of Surf ace Area Adsorption Measurements by Ne1sen and Egge under the title of continuous flow method. It can be measured by the method published by Rtzen.

The methanol value can be measured by the following method. 200mg powder and 50ml water was placed in a 250 ml vibrating flask and stirred magnetically. 10 m of methanol The end point of a zero titration, which is added at a rate not exceeding 1/min, is the point at which all of the powder is suspended (x m Il). The methanol value (B) is then calculated as follows: Commercially available types and specially prepared samples were used in the present invention.

The preferred proportion of fumed silica to toner material ranges from 0.5 to 3% by weight. It is.

In addition to fumed silica, e.g. Metallic soaps such as zinc stearate can also be used as additional flow improvers.

Other flow-improving additives are based on submicron-sized fluorine-containing polymer particles. ing.

The preferred ratio of metal soap such as zinc stearate to toner material is 0.0 It is in the range of 5 to 1%. The same is true for fluorine-containing particles.

The toner compositions used in accordance with the invention may be used, for example, in European Patent Application No. 01285 No. 69, No. 0170421 and No. 89200192.6. It can contain conventional resin binders such as No. An interesting example is a European patent application No. 0279960, which includes (1) styrene or styrene congeners; body, (2) an alkyl acrylate whose alkyl chain is straight and contains at least 8 carbon atoms; ester or alkyl methacrylate monomer, and (3) Crosslinked monomer containing at least two ethylenically unsaturated groups Partially crosslinked polyesters, which are copolymers of For example, there is one described in published British patent application no. 2082788A. Polycondensation with less than 1 equivalent of ethoxylated and/or propoxylated bisphenol A There are binder compositions derived from terephthalic acid. Furthermore, in the toner particles Other conventional polymers suitable for use as binders can be used.

Other resins or pigments that modify the melt particle size to further optimize toner properties and/or a release agent can be used.

Toner melt from the fuser rollers, especially when using heated roller fusers. Advantageously, additional release agents should be incorporated into the toner composition to aid in release. especially Suitable release agents are tack-promoting compounds such as talc, silicones, fluorine-containing polymers. and natural or synthetic waxes.

A particularly low coefficient of friction (steel) is used to prevent toner offset onto the fuser rollers. Suitable fluorine-containing vinyl polymers having a static friction coefficient of less than 0.2) are It is described in Japanese Patent No. 4059768.

Particularly suitable for preventing toner offset are waxy polyalkylene resins. polypropylene, more particularly isotactic polypropylene with an average molecular weight of less than 15,000 The colorant used in the toner particles is a colorant commonly used in dry electrostatic toner compositions. Any inorganic pigment (including carbon) or solid organic pigment or dye used, or can be a mixture thereof. For example carbon black and its congeners , e.g. lamp black, channel black and furnace black, e.g. 5PEZIALSCHWARZIV (Degus, Frankfurt, Germany) sa product name) and CABOT REGAL 400 (Cab in Boston, USA) Corp. (trade name) can be used.

Addition of colorant also affects the melt viscosity of the toner.

Addition of colorant, if desired, may be considered to bring the melt viscosity of the toner into the desired range. That's good. The colorant is added to and mixed with the fused toner composition. This is cooled crush and grind to obtain the desired particle size.

Apart from the colorants mentioned above, the use of viscosity-modifying pigments can be taken into consideration. So Types of interest for this purpose include titanium dioxide (rutile), barium sulfate (para ), calcium carbonate (calcite), ferric oxide (Fe2rs), fuemata iron oxide) and triiron tetroxide (Fe30a-magnetite), cupric oxide, and other The latter pigments, which can also be used as magnetic or magnetizable pigments, are useful for example in magnetic toners. It can also act as a color substance. Accordingly, the present invention provides for Also includes na.

Typical solid organic dyes used in electrophotographic toners are so-called pigment dyes. This includes phthalocyanine dyes, such as copper phthalocyanine, metal-free phthalocyanine Contains dyes, azo dyes, and metal complex salts of azo dyes.

The following dyes in the form of pigments are shown for illustrative purposes only: FANALROSA B 5upra Pu1ver (BAS of Ludwisschafen, Germany) F AG product name), )IELIOGENBLAII LG (metal-free BASF AG trade name for talocyanine blue pigment), MONASTRAL BLtlE (copper phthalocyanine pigment, C, I-74160), IELIOG ENBLA II 8 Pu1ver (BASF AG product name).

! (ELIOGENBLAU HG) Zen's Bayer AG product name, C, 1,7416G), BRILLIAN T CARMIN 6B (C, L 18850), and VIOLET FA NAL R (BASF AG product name, C, 1, 42535).

Typical inorganic pigments used in electrophotography include carbon black, black iron oxide ( m) and mixed oxidized steel (■) / chromium oxide (■) / iron oxide (m) powder, Milorivre -, ultramarine cobalt blue and barium permanganate, and further o French patent filed on December 23, 1963 by dak Ltd. No. 1394061 and Harris Inlertype Corporation French Patent No. 14393 filed on April 27, 1965 by Examples include the pigments described in No. 23.

The coloring substance is usually used in a concentration range of 5 to 20% by weight, calculated based on the total weight of the toner. use.

Apart from insoluble coloring substances, the use of soluble coloring substances can also be considered.

Toner particle compositions are used to enhance the negative or positive chargeability of toner particles. Add a charge control agent to the For example, to generate negatively charged and sticky toner particles, As described in the published German patent application (DE-OS) No. 3022333, charge control agents such as Opened German Patent Application (DE-OS) No. 2362410 and U.S. Patent No. 4 263389 and 4264702. Ru. A very useful charge control agent for imparting positive charge polarity is BONTRON NO. 4 (trade name of Oriental Chemical Industry Co., Ltd. in Japan), which is a toner particle composition. For example, resin acid-modified nigrosine dyes can be used in amounts up to 5% by weight. Ru. A very useful charge control agent for providing negative charge polarity is BONTRON S3. 6 (trade name of Oriental Chemical Industry Co., Ltd. in Japan), which has a toner particle composition. It is a metal complex dye which can be used in an amount of, for example, up to 5%, based on the product.

In the production of toner particles, coloring materials and other additives are added to the molten resin and mixed homogeneously. Knead until a mixture is obtained.

The solid mass obtained after cooling is crushed, for example in a hammer mill followed by a jet mill, and then and crush. After this operation, air classification was performed.

For a constant charge density of the latent image charge-bearing surface, the given table Hei 4-506420 (6) The maximum developed density that can be obtained with toner particles of this size depends on the charge/toner particle mass ratio. It is decided. In the case of two-component developers, this is due to frictional contact with carrier particles. It is essentially determined by the triboelectric charge obtained.

The toner compositions of the present invention should preferably be used in combination with carrier particles. Ru.

Development involves so-called cascading of toner particles onto an imaging surface containing a pattern of electrostatic charges. This can be done by brushing or using a magnetic brush. carrier grains The toner particles adhere to and surround the carrier particles. Carrier particles can triboelectrically acquire a charge of opposite polarity. It can be electrically conductive, insulating, magnetic or non-magnetic, as long as it is For brush development, they must be magnetic).

In developing an electrostatic image to form a positive reproduction of the original, carrier particles are The composition and/or toner particle composition is such that the toner particles have a polarity opposite to that of the electrostatic latent image. Select to obtain a charge with a specific property. Thus, toner adhesion occurs in the image area. . Instead, in reversal reproduction of electrostatic latent images, a carrier composition and a toner are used. The particle composition is such that the toner particles acquire a charge having the same polarity as that of the electrostatic latent image. to create toner adhesion in non-image areas.

Useful carrier materials for cascade development include sodium chloride, ammonium chloride, aluminum potassium chloride, Rochelle salt, sodium nitrate, aluminum nitrate um, sodium chlorate, granular zircon, granular silicon, silica, methyl methacrylate Carrier materials useful in magnetic brush development include polymeric coatings, Steel with or without coating, nickel, iron, ferrite, ferromagnetic materials, e.g. Contains magnetite. Other suitable carrier particles include, for example, U.S. Pat. Magnetic or Contains magnetic material. Many of the carriers mentioned above and representative are conductive carriers. US Pat. Nos. 2,618,441, 2,638,416 and 2 It is described in No. 618522, No. 3591503 and No. 3533835. , described in U.S. Pat. No. 3,526,533 for polymer-coated carriers. There is. Oxide-coated iron powder carrier particles are described, for example, in U.S. Pat. No. 3,767,477. It is described in.

U.S. Patent Nos. 3,847,604 and 3,767,578 disclose nickel-based Regarding carrier beads. The diameter of the final coated carrier particles is approximately 30 μ to about 1000 μ is preferred, when the carrier particles are static during the cascade development process. It has sufficient inertia to avoid adhesion to electroimages and can be operated in magnetic brush development. withstand losses due to centrifugal force. Carrier can be combined with toner in any suitable combination. can be used with the toner particles, and generally satisfactory results are obtained using about 1 part by weight of the toner particles. from about 5 to about 200 parts by weight.

The toner compositions of the present invention can be used on any suitable electrostatically charged surface capable of retaining a charge, especially under normal light. Used to develop electrostatic latent images on photoconductive layers known to those skilled in the art, including conductors. Can be used.

Hot roll melting of toner is described, for example, in the Journal of ImagingTec hno togy Volume ■, No. 6 (December 1985), pp. 261-279 It is described in. And a heated roller melting method and a static method for carrying out this method. The electrographic device is described in detail in the aforementioned European Patent Application No. 0279960. while infrared melting is described in US Pat. No. 4,525,455.

The following examples illustrate, but do not limit, the invention. part, ratio and Percentages are by weight.

Knee L crab 11 Glass transition temperature of 51 °C, melting point in the range of 65-85 °C, acid number of 13.9 and 25 Measured in a mixture of phenol/orthodichlorobenzene (60/40 by weight) at °C Propoxylated bisphenol having an intrinsic viscosity of 0 and 175 dI2/g when ATLACT500, a polyester A fumarate polyester (Wilmin, USA) At1as Chemical Industries Inc.

(trade name) 90 parts, carbon black Cabot Rega 1400 (US) Put 10 copies (trade name of Cabot Carp, Boston, USA) into a mixer, and mix 12 A melt was created by heating to 0°C. At this time, the lines started to mix up. After about 30 minutes, the crosstalk was stopped. The mixture was cooled to room temperature (20'C). Crush the mixture at that temperature to a fine powder to form a powder. This was further reduced in particle size by jet milling. aforementioned Air classification was performed using a device that The toner was then measured using a Coulter Multisizer device with a 30μ measuring tube. The particle size distribution was measured. The results are shown in Table 1 below.

The second column of this table shows the toner volume located between the isospherical diameters (μ) shown in the first column. – indicates the differential percentage of particles.

Item 31'll of this table shows the percentage value of the second column on a cumulative basis.

Analysis of the particle size distribution of toner particles made by the method described above shows the following results: Volume percentage of particles larger than 3μ: approximately 2.5% Volume percentage of particles larger than 4μ Fraction: Approximately 1% Volume percentage of particles larger than 5μ: Approximately 1% Toner selected here The particles were introduced into a mixing device with an average particle diameter of 7 nm and a methanol value of 56 and a Aerosil, a fumed hydrophobic silica with a specific surface area of 60m”7g Use R812 (product name of Degussa AG, Germany) as a toner as follows. mixed with.

Add 0.5 g of fumed silica particles to 100 g of toner particles with an average diameter of 9 mm. Contains 100 ceramic balls with diameter and density of 2.4g/cm' The mixture was heated in a metal box (10 cm diameter) at 3° orpm for 30 minutes. (This method is shown in Table 2 as Method A).

Another method that can be used is thermalized at 20°C and rotated at a speed of 2000Orpm. Janke and Kcenkel Labormill equipment type IKA Adding toner and flow enhancing additives to M2O. This machine is manufactured in Germany. Jankeand Kunkel GmbH in Utaufen, r to A Labo Available from rtechnik. This mixing method of mixing flow enhancer with toner is It is shown in Table 2 as Method B.

11 Anti-Kasadama J An electrophotographic recording element (i.e. an ASzSe3 coated conductive drum, which is positively charged and whose imagewise exposed) and developed with a magnetic brush. This is 50EMU/g Typical ferrite carriers (Ni-Zn type) with magnetization A developer obtained by mixing the toners was used for adhesion. The average carrier particle diameter is approximately 6 It was 5μ.

After adding toner particles to the carrier in an amount of 265% by weight relative to the carrier, the present The image agent had a diameter of 6 cm and was activated by rotating a metal box at 300 rpm for 30 minutes. child The apparent filling degree at this time was 30%.

When the average equivalent toner particle diameter is large, the amount of toner relative to the weight of the carrier should be large: this means that in both cases the toner to carrier This means that the amount by surface coverage remains the same.

The electrostatically attached toner is transferred by applying a positive voltage of 3 kV to the metal roll. Ta. This roll is held in near-ohmic contact with the back side of the paper sheet that acts as the receiving material. , the front side of the receiving material was therefore kept in close proximity to the toner image on the photoconductor.

Liquid B The imagewise transferred toner particles are described in Example 8 of U.S. Pat. No. 4,525,445. A radiation melting apparatus operated with an infrared melting element as described was fed.

Kunami Nimasu l Wataru 1j Toners with a normal particle size distribution characterized by an average particle diameter of e.g. 10-15μ When particles are used, the overall resolution of electrostatography in copiers is typically about 35μ lines. limited to line-pair structures where the spacing between consecutive black lines is less than 35μ; means that it cannot be faithfully reproduced by global electrostatic recording methods. However However, with the toner according to the present invention, lines with thicknesses down to 25μ can be produced. We were able to faithfully reproduce the original image on the final copy.

The above was measured as follows: Deutche F, Munich, Germany. orschungsgesellshaft fuel Druck undR FOGRA-PMS published by eproduktiontechnik e,v -5system matches LIGRA-Offset-Testkeil 19 82 wedges were copied in an electrostatographic apparatus as described above.

The wedge shows a view consisting of concentric circles with increasing resolution. Electrostatic record as mentioned above The final copy corresponds to the finest concentric circle that can be visually identified on the copy made by the recording method. The ultimate resolution on the pixel was 25μ.

By replacing the conventional optics for illuminating the photoconductive drum with high quality optics. The ultimate resolution on the final copy was 8μ when using the toner according to the invention. .

BiG・bi・・の゛l The bulk density of the toner particles was determined by Beckman Instru, Gangy, France. Beckmann Air Comparimate available from ments The measurements were carried out in a conventional manner using an apparatus such as R.

The apparent density of toner particles was measured by the following method.

100 g of toner particles are vibrated for several minutes in a bottle with a capacity of about 500 ml; Place on a vibrating sieve with a rear mesh size of 1 mm and a diameter of 7 cm, and heat at 50 Hz. It vibrates at a frequency and an amplitude of 1 mm. The stirred toner particles are passed through a sieve to a height of 1. 7 cm and a diameter of 7 cm. After equilibration for 2 minutes , discard toner particles exceeding the height of the receiver, and calculate the weight of the toner particles contained in the receiver. Then, the apparent density is calculated as follows.

K stand straight! -11 Table 2 below shows experimental results for toners made by the method described above. This is it If so, change not only the fine grinding and classification parameters but also the concentration and method of adding the flow enhancer. Ta. The resolution of the final copy in electrostatography using these toners is also shown.

Table 2 below shows the average diameter of toner particles, the apparent ratio of bulk density to density, and the final solution. The bulk density of the toner particles, as shown in the image results, was 1.17 kg/dm'.

The particle size distributions of the toners with reference numbers 1.2 and 3 meet the criteria. Same also applies to the filling rate criteria.

The observed resolution is very good. Deviation from the particle size standard is caused even if the filling standard is met. Even if the image quality is increased, the image quality will deteriorate rapidly.

scarcity - once 1 2.6 2.8 2.4 0.21 25 82 3.6 4.1 3.2 0.26 25 103 4.5 5.0 4.0 0.25 20 124 5.7 6.3 5.0 0.31 25 125 6.7 7.5 6.0 0.32 25 196 11.313.5 9.5 0.31 40 30 In Table 2: dv represents the average diameter of toner particles by volume; dn represents the average diameter of toner particles by number. Represents the uniform diameter; d represents (dv x dn) +/z; resolution 1 is the normal copying machine faithfully reproduced on the final copy made with the electrostatic recording device described above in some embodiments. Represents the thickness in μ of the finest line on the original test wedge; resolution 2 is the electronic recording as described above. μ of the finest line on the current test wedge faithfully reproduced on the final copy made by the device. represents the thickness of However, in this case, a normal optical device for illuminating the photoconductive drum is used. Replace with high quality optics; ρapp/ρbulk is the bulk density of the toner particles. The apparent appearance represents the ratio of densities.

From the above results, it is clear that if the photoconductive drum is irradiated with high-quality optical equipment, then this It is also clear that the resolution obtainable with the toner according to the invention is up to 8μ.

The particle size distribution of the toner with reference number 2 in Table 2 is shown below. This toner is It was made using the same method as above. However, the aforementioned A, F, G, /A, T, P, A Different particle size fractions can be obtained by different milling and classification settings of lpine combination equipment. It was.

1, 59 1.13 100.01 2,00 3.44 98.88 2, 52 10.34 95.44 3, 19 26.97 85.10 4, 01 44.79 58.13 5, 05 11.52 13.34 6, 36 0.39 1.82 8.01 0.29 1.43 10, 09 0.19 1.14 12, 71 0.19 0.95 16, 01 0.00 0.76 20, 17 0.76 0.76 25, 41 0.00 0.00 Columns 2 and 3 have the same meaning as the corresponding columns in Table 1. The following results are shown: Volume percentage of particles larger than 3μ = 88% particles larger than 4μ Volume percentage of = 58% Volume percentage of particles larger than 5 μ: 15% However, this Apart from the high resolution obtained with the toner particles according to the invention, the overall When evaluating technical performance, the various processing characteristics of electrostatic recording methods must also be taken into account. No.

Therefore, the electrostatic properties of the toner composition prepared by the method described above were evaluated. .

Reference ρ app/toner Toru knee Kagami to -zu- u p- mutual 1 top 2Lヱleft 1L'' 1 關7 7 ．． 79 5.31 6.4 0.3 0.43 B 50 58 4.16 2 ．． 76 3.4 3 0.32 B 75 809 4.16 2.76 3. 4 3 0.27 A 100 180010 3.35 2.43 2.8 - 0.15 -11 2.8 2.4 2.6 - 0.14 -12 2. 8 2.4 2.6 0.75 0.18 B 75 20132.8 2.4 2.62 0.26 B 75 20dn, dv, d, p app/p "bulk" has the same meaning as described above. The method is to mix flow-enhancing additives into the toner. Indicates methods A and B used to combine; The time is the time when the flow enhancing additive is mixed with the toner in either Method A or B. (seconds); Toner weight indicates the weight of the toner in grams; Concentration indicates the added Concentrations of eumed silica (Aerosil R812) are shown.

The particle size distribution of the toner with reference number 8 in Table 4 above is shown below.

Table - 11 each other 1.59 3.34 100.00 2.00 5.82 96.66 2, 52 11.63 90.84 3, 19 21.38 79.21 4, 01 28.14 57.83 5, 05 20.09 29.69 6, 36 7.58 9.60 8.01 2.02 2, o2 10, 09 0.　DOO,00 The second and third columns have the same significance as the corresponding columns in Table 1. Analysis of particle size distribution is below. The following results are shown below.

Volume percentage of particles larger than 3μ = 82% Volume percentage of particles larger than 4μ: 5 8% Volume percentage of particles larger than 5μ: 31% Toner with reference number 13 in Table 4 above The particle size distribution of is shown below.

1, 59 9.51 100.02 2, DO21,9390,51 2, 5240, 9468, 58 3, +9 22.98 27.64 4, 01 3.27 4.66 5.05 0.26 1.39 6.36 0.12 1.13 8.0 + 0.08 1.01 +0.09 0.00 0.93 +2.71 0.31 0.93 16, 01 0.32 0.62 The second and third columns have the same significance as the corresponding columns in Table 1. Analysis of particle size distribution is below. The results are shown below.

Volume percentage of particles larger than 3 μ: 38% Volume percentage of particles larger than 4 μ: 5 Volume percentage of particles larger than %Sμ: 1% Looking at the electrostatic recording method, the following points are noted. The cleaning problem of the photoconductive drum caused by the strong adhesion of toner particles was evaluated. The transfer efficiency of toner particles from a photoconductive drum to a paper substrate at a transfer station rate, fog on the paper substrate, magnetic brush quality and toner transfer to the developer station. Overall liquidity and supply.

Among the above-mentioned toner compositions, toners with reference numbers 7.8.9 and 13 are the above-mentioned toners. When looking at the method characteristics, it showed good performance overall. Reference numbers 10 and 11 The toner particles exhibited poor performance in all of the process characteristics described above. On the other hand The toner composition with reference number 12 has medium properties regarding transfer efficiency and magnetic brush quality. Poor performance was observed in terms of performance, cleaning, fogging, and toner fluidity.

From the foregoing, the ratio of bulk density over apparent density is determined by the static A critical requirement that determines whether a good overall performance in electrography We can conclude that there is.

Therefore, the apparent bulk density of toner particles is expressed as a ratio of density and filling standards and books. In order to realize the purpose of the invention, that is, direct image quality by dry xerographic donor development, It is an essential requirement to combine both the particle size distribution and the selected criteria.

Similar experiments were performed with other silica species showing different specific surface areas and methanol values. (shown in the table below). and combined with toner reference number 2 at a concentration of 2% by weight.

The app/bulk value was measured. This is a measure of the specific surface area (Am”/g). Condition where the product of ethanol value (8% volume) is equal to or greater than 10000 satisfying the conditions set forth herein for ρapp/ρbulk. , ensuring good quality and performance overall.

The first column shows the experiment number using various flow enhancing additives. The second column shows ρapp/ρb. The third column shows the specific surface area of the flow enhancing additive expressed in m”/g. vinegar: The fourth column shows the methanol value of the flow enhancing additive; the fifth column shows the methanol value for the specific surface area. indicates the product multiplied by the value.

Table 7 shows that the overall realization of the object of the present invention, i.e., direct development by dry xerographic donor development. Particle size distribution is important for achieving image quality, and the apparent density of toner particles that exceeds their bulk density is expressed as a ratio of density. filling criteria (the realization of such density is based on the product of specific surface area and methanol value) This is the result of the use of flow-improving additives that meet the exacting standards of It can be concluded that this occurs.

■, Patent application number PCT/EP 90101027.

2. Name of the invention Dry electrostatic recording toner composition 3. Patent applicant Representative Shipt, Shuanin Vuan Del4, Agent Address: 6th floor, Shinei Building, 1-6-20 Tosabori, Nishi-ku, Osaka May 27, 1991 Day 6. List of attached documents (1) One translation of the written amendment Scope of claims (correction) 1. Dry electrostatic recording toner particles suitable for use in developing electrostatic charge patterns. (I) 90% by volume or more of the toner particles are larger than 0.5μ; have the same particle size diameter smaller than 7 μ; (■) About 50% or more by volume of the toner particles have the same particle size diameter of less than about 5μ. It is characterized by classified particle size distribution, (m) said toner particles are present on their surface at least 0.1% by weight and at most It has fine inorganic microparticles that act as a flow enhancing additive at a concentration of 5% by weight; Fine inorganic microparticles have the following relationship AXB>10000 The specific surface area (A) (m”7g) that satisfies the following is multiplied by the methanol value (B) (volume%). It has the product as a characteristic, As a result, the ratio of the apparent density to the bulk density of toner particles is calculated using the following formula: Dry electrostatic recording toner particles characterized by satisfying the following requirements.

4. Fine inorganic microparticles are coated with hydrophobic group-containing units, and methane larger than 2o 2. The dry electrostatic recording toner according to claim 1, wherein the toner generates a wall value.

5. The scope of claims in which the fine inorganic particles have a specific surface area greater than 150 m"7 g. The dry electrostatic recording toner according to item 1.

6. Claims 1 to 5, wherein the fine inorganic particles are humid inorganic substances. The dry electrostatic recording toner according to any one of the items.

9. Claim 6, wherein the fumed inorganic substance is fumed silica. dry electrostatic recording toner particles.

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Claims (1)

[Claims] 1. dry electrostatic toner particles suitable for use in developing electrostatic charge patterns; wherein the toner particles are (I) at least 90% by volume of the toner particles are larger than 0.5μ; have the same particle size diameter smaller than 7μ, (II) about 50% or more by volume of the toner particles have the same particle size diameter of less than about 5μ; It is characterized by classified particle size distribution, (III) said toner particles are enriched on their surface by at least 0.1% by weight; at least 5% by weight of the flow-enhancing additive, said flow-enhancing additive meeting the following relationship A: ×B>10000 The specific surface area (A) (m2/g) that satisfies the following is multiplied by the methanol value (B) (volume%). It has the product as a characteristic, As a result, the ratio of the apparent density to the bulk density of toner particles can be calculated using the following formula: app/bulk>0.2 Dry electrostatic recording toner particles characterized by satisfying the following requirements. 2. At least 90% by volume of toner particles have the same particle size larger than 0.5μ and smaller than 6μ 50% or more by volume of the toner particles have the same particle size diameter of less than about 4μ. Dry electrostatic recording toner particles according to claim 1. 3. At least 90% by volume of toner particles have the same particle size larger than 0.5μ and smaller than 5μ 50% or more by volume of the toner particles have the same particle size diameter of less than about 3μ. Dry electrostatic recording toner particles according to claim 1. 4. The flow-enhancing additive is coated with hydrophobic group-containing units and has a methanol content of greater than 20 The dry electrostatic recording toner according to claim 1, which produces a value. 5. Claim No. 1, wherein the flow-enhancing additive has a specific surface area greater than 150 m2/g. The dry electrostatic recording toner according to item 1. 6. Any of claims 1 to 5, wherein the flow enhancing additive is fumed silica. The dry electrostatic recording toner according to item 1 above. 7. Fumed silica is present in an amount of at least 0.5% by weight based on the weight of the toner. Dry electrostatic recording toner particles according to any one of claims 1 to 6. 8. Claim No. 1 containing a colorant dispersed or dissolved in a toner binder resin Dry electrostatic recording toner particles according to any one of items 1 to 7. 9. The dry electrostatic recording toner according to claim 8, wherein the colorant is carbon black. - Particles. 10. Claims 1 to 9, wherein the toner particles contain a negative or positive charge control agent. The dry electrostatic recording toner particles according to any one of the above. 11. The toner particles are formed in a cascade of electrostatic charge patterns or for magnetic brush development. Any one of claims 1 to 10 mixed with carrier particles. dry electrostatic recording toner particles.