JPS58184950A - Magnetic toner - Google Patents

Abstract

PURPOSE:To prevent trouble of dispersion of an amt. of charge generated on the surfaces of toner particles even when a positive charge controlling dye is used, development fog, toner scattering, carrier staining, etc., and further, deterioration of efficiency of toner image transfer in high humidity, and to make durable for a long-term storage, by adding fine silica powder synthesized by a wet method, and synthesizing a magnetic material by the wet method. CONSTITUTION:Anhydrous silicon dioxide, and silicic acid compds. are all used for fine silica powder. Its particle diameter is in the range of 0.01-2mum as an average primary particle diameter. When it is added to developer by 0.1-3wt% of developer, it exhibits positive chargeability having superior stability. It is added in a state of 0.01-3wt% fine silica powder being attached onto the surfaces of the toner particles. This powder contg. >=85% silica is preferable, it has minute pores in the inside, and an amt. of water combined with the silanol groups of the surface of the silica by van der Waals force remains comparatively stable against change of the environment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for simulating shadows or magnetic latent scratches in photography, electrostatic recording, electrostatic printing, magnetic recording, etc. In particular, the present invention relates to a magnetic toner that is uniformly and strongly positively charged, visualizes negative electrostatic charges, and provides a high-quality 1IIi image in a direct or indirect electrophotographic development method.

Conventionally, for electronic copying, U.S. Patent No. 2.297,69
No. 1 Akira d-14, many methods are known, but in general light guiding proboscis j! A one-dimensional latent image is formed on the photoreceptor by various means using t, and then the latent image is developed using a toner powder (hereinafter referred to as toner), and if necessary, it is printed on paper or the like. A toner image is transferred onto a transfer material, and a copy is obtained by crushing the toner image by heating, pressure, solvent vapor, or the like. −
When the method includes a step of transferring a toner image, a step of removing residual toner on the photoreceptor is usually provided.

IL2L visualization methods using approximately 2L a-images include, for example, the magnetic brush method described in U.S. Pat. No. 2,874,063, and U.S. Pat.
Samikumo, Method using conductive magnetic toner described in U.S. Patent No. 3,909,258, Japanese Patent Publication No. 4
1-9475, etc., methods using various abhorrent magnetic toners are known.

As toners used in these developing methods, fine powders in which dyes and pigments are dispersed in natural or synthetic resins are conventionally used. For example, binding mA such as polystyrene
Particles obtained by dispersing a coloring agent in ¥I and pulverizing the particles to a size of about 1 to 30 microns are used as toner. As the magnetic toner, one containing magnetic particles such as Madai Tite is used. In the case of a system using a so-called two-component developer, the toner is usually glass beads,
It is used by mixing it with carrier particles such as iron powder.

Among them, as a visual imaging method using a one-component developer consisting only of toner, the so-called induced image method (for example,
-491) is well known. In short, this method involves attaching conductive and magnetic toner to a sleeve containing a weight to form a magnetic brush of the toner, and then bringing the magnetic brush into static contact with a latent image carrier to transfer a clear image to the toner. It is similar to salt. In this visual method, toner! When the magnetic plan is made to face the static image of A, a static image of 1 and a negative charge of 1 are induced in the toner. Between Hiroki Seiden! The power of attraction is developed by the force of attraction.

In addition, an insulating magnetic toner is attached to the sleeve containing the bleeding to form a toner magnetic brush, and the toner is electrically charged by rubbing against the sleeve, and the magnetic brush is held in place.
tm (H method is also known, in which the image is created with toner by touching or bringing it close to the image carrier. For example, Takkai No. 49-17739 using capsule magnetic 1 raw toner, insulation- The Hikiichisho method using a fresh toner is described in detail in Shokai No. 50-45639.

These one-component developing methods do not use a carrier in the developer, so the mixing ratio of carrier and toner is not uniform, and stirring is required to mix the carrier and toner sufficiently uniformly. Since the operation does not require public safety, there is an advantage that the entire current device can be constructed in a simple and compact manner. To the carrier over time [r: based on J method, boundary! :1! However, these li magnetic toners do not cause any inconvenience such as deterioration of surface quality.
In general, particles tend to be dispersible into toner particles,
It is important to obtain a uniform toner without any unevenness in the manufacturing process, and <V is a loquat-averse magnetic toner, and V is also the cause of a decrease in the toner's instantaneous resistance. In addition, toners have poor impact resistance and poor durability (buttons also have various problems).Furthermore, magnetic toners have poor susceptibility and are susceptible to sagging.

In addition, the magnetic material used in the positive charge '-j' toner rC, which has a negative electrostatic charge,
Not all magnetic materials can be used for one change.
In many cases, this results in inconvenience. For example, since the toner is used for 1 year and 4 times, it is custom-made for the Arashiko copy.
Takashi VC current: characteristics change, environmental stability is poor, 'E7
If the name 'C' turns into a moth while being used, then the name 'C' may turn into a nuisance. This is a problem that I mentioned here, here, and here.
This is caused by the inconvenience of the surface conditions of the magnetic material.

Sign iC, :li expression? When a toner is made using the A column with the 5'C remembrance 1, a strong tendency towards stiffness appears, and in some cases: it does not show positive charging property or shows negative 1 wax property. This results in a toner with extremely poor development characteristics. Even if it exhibits excellent positive chargeability, it cannot be exposed to high temperature, high humidity, or low a
This is not preferable because it tends to cause a decrease in thi image density under conditions of high temperature. This phenomenon is thought to be due to the non-uniformity of the trailing points on the surface of the magnetic material, which occurs during firing and mechanical crushing during the production of the magnetic material by the dry process. This is due to the non-uniformity of the shape of the magnetic material, that is, the unevenness.
Moreover, it is easily inferred that this is due to the unevenness of particle diameters during pulverization. When a magnetic substance having such non-uniform activity is dispersed in the ijB layer sphere fat, the wettability between the resin and the magnetic substance on one surface is poor, and the dispersion is slow and poor.

For this reason, in toner containing the magnetic material, many magnetic particles are exposed on the surface, and the magnetic material M content among toner particles varies, resulting in increased load! This causes non-uniformity of properties and magnetic properties, which adversely affects various objects during development.

In fact, when the toner containing all the D pillars is charged by the toner film or the am of the toner and the sleeve, the electric charges are concentrated on the fine irregularities on the surface of the di pillars.◇
. This charge is thought to form a charge at the interface with the resin, but because it is concentrated, it is distributed by reducing the influence of humidity.For example, under local humidity earthquakes, the charge is Under low humidity, the generated charge accumulates, causing attenuation of the
This results in an increase in the reflection force on a toner carrier such as a sleeve due to toner charge-up, resulting in an insufficient J hyperactivity force on the latent image of the toner, causing a decrease in image density.

Father, the positive 11 used in dry-forming magnetic toner like this
As a load control agent, for example, amine compound cleavage, quaternary
These include ammonium compounds and organic dyes, and basic dyes and their salts. Common positive charge control agents include be/zyl dimethyl-hexadecyl ammonium chloride, te/root trimenal ammonium chloride, nigrosine base, nigron hydrochloride, safrani/r, and crystal violet. Nigrosine base and nigrosine hydrochloride are often used as positive charge control agents. These are usually treated with thermoplasticity 1 and grease-resistant, heat-melted and dispersed, finely pulverized, and adjusted to a suitable particle size as necessary before use.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor female determination. However, decomposition during heat kneading, mechanical abrasion, changes in humidity conditions, etc. This causes a phenomenon in which charge controllability deteriorates. When a toner containing these dyes as a charge control agent is used in a copying machine using the bulk method, the dye decomposes or decomposes as the number of strokes increases.
Causes toner deterioration during durability.

However, since it is difficult to uniformly disperse these charge control dyes in thermoplastic resins, we have developed a method to improve the ductility between toner particles obtained by pulverization. It has the fatal flaw of evoking differences. For this reason, various methods have been used to more uniformly disperse these dyes into #11i. For example, in order to improve the compatibility with the basic diguco/con dye, it is used by forming a salt with some fatty acids, but often the unreacted Bit5dl or salt is used. The dispersion generation station is exposed on the toner surface and contaminates the toner carrier, etc., and the toner's tJiL! This causes a decrease in visual quality, sharpness, and a decrease in image sharpness. Alternatively, due to the dispersion of these dyes into the resin as above, it is not possible to obtain a uniform hot melt charge after vCXh curing and mechanically pulverizing and mixing the dye powder and cutting resin powder. In addition, many of the positively charged dyes are hydrophilic, and due to poor dispersion in these resins, they are crushed after bath melting and mixed. When the toner is used in high humidity conditions where the dye is exposed on the toner surface, the dye is hydrophilic, so it has the disadvantage that a high-quality 1m statue will turn out to be an ornate Buddha. Similarly, the conventional positive load controllability was improved by ・h'
When heavy hitting is applied to the toner, variations in the electric current generated on the surface of the toner particles occur between the toner particles or between the toner and a toner carrier such as a sleeve, resulting in development fog, Problems such as toner scattering and carrier contamination may occur. However, when a large number of copies are made, they sometimes appear in noticeable agglomerations, and in reality, there are more than 14 clumps in a duplicator.

However, under high humidity conditions, the toner image transfer efficiency is significantly reduced, making it unsuitable for use. Furthermore, even at room temperature and humidity, when the toner is stored for a long period of time, due to the instability of the positive charge control dye used, the toner often aggregates and becomes unusable. .

The present invention solves various problems related to the conventional positive #magnetic toner as described above, uniformly deposits (positively charges), visualizes negative #P11L charged image, and achieves bird quality. As a result of intensive research with the aim of providing image ablation for electrophotography that produces images, we have developed a toner using a magnetic material synthesized by a formula method and silicic acid fine powder synthesized by a wet method. It has been found that by containing it, a 11N agent for electron-donating A can be obtained which exhibits excellent magnetic properties.

That is, an object of the present invention is to provide a toner that solves many of the drawbacks mentioned above regarding conventional positively charged component-based magnetic toners.

That is, an object of the present invention is to ensure that the amount of frictional charge between toner particles or between toner and a toner carrier such as a sleeve is stable and uniform, there is no fogging, toner scattering, or toner aggregation, and there is no latent charge. The purpose of the present invention is to provide a developer that provides a clear image that is extremely faithful to the image. 1 Another purpose of the history is to create a developer that reproduces a stable image that is not affected by humidity such as low or high humidity, that is, the amount of toner charge is uniform and stable under any humidity conditions. ,,Si1. The object of the present invention is to provide a developer having constant development characteristics and transfer characteristics.

Still another object is to obtain a constant Kf constant visual image for the repeated image 1;
Thank you for providing a developer that exhibits transferability.

Another purpose of the project was to provide a developer that would not deteriorate over a long period of time even when used in high-speed copying machines.

Another purpose of the present invention is to provide a stable developer with consistent quality.

The characteristics of this magnetic toner include a binder resin and a magnetic material as main components, and silicic acid fine powder synthesized by a wet method. It is something that

Conventionally, fine powder silica called colloidal silica has been used as a pulling agent (for example, Aerosil 200.R manufactured by Nippon Aerosil Co., Ltd.).
9727i, etc.) (+-additives) are well known.However, even in toners containing dyes that have positive charge control properties, when these two types of silica are added, the chargeability becomes negative 5C.
As a result of research into the above phenomenon, the present inventors found that the warp force produced by the conventional dry method is unsuitable for visualizing negative electrostatic charge images. I found a way to reduce the company's contributions or reverse the polarity. When conducting detailed studies for the purpose of obtaining Toner 7 exhibiting stable and high positive chargeability, it was found that it is effective to add silicon # fine powder synthesized by a wet method to the toner.

As a method for producing N-free silicic acid fine powder by a wet method, a conventionally known method can be used.

For example, the decomposition of siliceous sodium by acid can be expressed as a general reaction formula (the reaction formula is omitted below): Nm1011x8101+HC/-)-HIO→5to
le nH10+NmC/Others, decomposition of sodium silicate with ammonia salt @ or alkali salts, alkaline earth metal silica from sodium silicate 11! There are a method in which a salt is generated and then decomposed with an acid to produce a result, a method in which a sodium silicate solution is converted to silicic acid using an ion exchange resin, and a method in which natural silicic acid or silicate is used.

The silicic acid fine powder mentioned here includes anhydrous silicon dioxide (silica) and aluminum silicate.

Any silicates such as sodium silicate, potassium silicate, magnesium silicate, and zinc silicate can be applied.

The particle size is preferably within the range of 0.01 to 2 μm as an average primary particle size. In addition, the application amount of these silicic acid fine powders is effective when it is 0.01 to 20% with respect to 1 weight of the developer, and especially when added by 11'7 or 0-1 to 3%. It exhibits positive chargeability with excellent stability.

Regarding the preferred form of addition, it is preferable that 0.01 to 3 parts by weight of the silicic acid fine powder be attached to the surface of the toner particles based on the weight of the developer.

Commercially available fine silicic acid powder synthesized by a wet method used in the present invention includes, for example, those commercially available under the following trade names.

Carplex Shiosugi Pharmaceutical Nip Seal Nippon Silica Toku Seal, Fine Seal Toku 1. Llltachi Vita Seal Taki Hijiruton, Silnetxu Mizusawa Kagaku Starsil Kamishima Kagaku Himezil Ehime Pharmaceutical Thyroid Fuji Devin Chemical fl+ S eye (Hiseal) P eye TSK + mrgb
Plate GlamsCo, (Pittsburgh plate glass) Dwresil Fl 1st store
ff-G@s@ll*chaftU eyes (Ultra Seal) Marqwart (Führstof Gesellschaft Maltort) Maooall (7) 7-ru) Hardmaa
and Ho1den (Hartman and Holken) Hoescb (Herash) Cbemis
cbs Fabrlk Hse@claK-G Sil-8tone 8t*o
er Rubber Co.

(Stoner Lover) Nalco N5lce' Ch
ew, C.

(Narco Chemical) Qumo (shoes) Ph1ladelp
hia Quartz Co.

(Philadelphia Quartz) Smtocall (Santocell) Ms+5san
to, chemical Co.

(Monnanto Chemical) I+mail (Imsil) Iyama+u>Is M
inerals Co,' (Isonois Mineral) Calcinall 8i1ikmarot
Cbsa-Bu5clx Fabrlk Hoesc
b.

(Calcium silicate) K-G (Hiemische Faprik Herash) Calsil Fllllstof
f-Ges*IIscmamouth Marqwart (Fyuurst Sofugesellschaft Martaort) Fortafil (Fortafil) Impsr
ial ChemicalIndIIstries,
Ltd.

(Imperial Chemical Industries) Migrocsl (Microcal) Joaepb
Cresfield kSoaa.

Lt. (Jiecef Crossfield & Sons) Ma+noall Hardmsn
and Ho1dan (Hardman and Holken) Vulkmail ()゛Kazir) Fmarbe
afabrikeo Bryer.

h, -G, (Fuburupenfapriken Bhaya) Tufknit Durbam
C,chemicals, Ltd.

(Doulham Chemicals) Silmos Shiraishi Kosu Starex Kamishima Kagaku Furikosil Takihiki These are used after being adjusted to have an average primary particle size in the range of 0.001 to 2μ.

In the present invention, as mentioned above, a fine silicic acid powder synthesized by a wet method is used and exhibits an effect. Among such fine silicic acid powders synthesized by a wet method, the fine silicic acid powder is particularly effective when 85%
Those containing the above Sing are desirable.

The wet process silicic acid powder used in the present invention, which exhibits stable and strong positive chargeability, has the same warping force as the dry process used in conventional toners, and has minute pores in its internal structure. It contains many water molecules bound by van der Waals forces to the seven lanol lobes on the surface of its pores. The water content in the internal structure of such silicic acid fine powder is different from the water adsorbed on the surface of dry process silica, and exists relatively stably even when the environment changes. The reason why the toner containing the silicic acid fine powder synthesized by the wet method, which is a feature of the present invention, exhibits stable positive chargeability against the environment is thought to be due to the stable water content in the internal structure. It will be done. The moisture contained in the internal structure of the silicic acid fine powder is expressed as the weight loss rate (ignition loss t) of a round wire when heated at a temperature of, for example, 900'O for 2 hours. The acid fine powder has a loss on ignition of 0.1 to 10% (preferably 0.3 to 6%).
) is desirable for marks.

The silicic acid fine powder synthesized by the wet method stably and strongly charges the toner positively, but as a result of studying the silicic acid fine powder synthesized by the wet method, it was found that 4 parts by weight of the silicic acid fine powder was mixed in water. It is clear that it is preferable to use a silicic acid fine powder whose PIN value when dispersed is 6 to 11 (more preferably 7 to 9). This is thought to be influenced by the various elements contained in the raw materials used to synthesize the silicic acid fine powder or in the processing agents used during the synthesis process, and the inclusion of alkali metal elements has a favorable effect. It is thought that there are.

Among these, experiments have revealed that those mixed with an appropriate amount of sodium ions have an effective effect.

In order to positively and stably charge the toner, it is particularly good to use silicic acid that satisfies the above conditions of Pi (ft) and contains an appropriate amount of sodium ions, and the preferred sodium content that gives the above PH of 11M is N. It is 0.01 to IO% in terms of SO4c.This is KI% in the 8iQ1 lattice near the surface of the silicic acid fine powder added to the toner.
4. Sodium ions absorbed by the human body or sodium ions attached to the surface of the silica* body absorb adsorbed water inside or on the surface of the fine powder. This is thought to be because it is effective in forming stable positive charges through the interaction of .

That is, among the fine silicic acid powders synthesized by the wet method used in the present invention, the pH of the aqueous dispersion is in the range of 6 to 11.
0.01 to 104) (converted to 0.01 to 104) (P of the water dispersion system preferred for ox) The sodium content required to maintain I is 0.
, 1 to 2.0%) is particularly preferred.

Next, examples of particularly preferred silicic acid fine powders synthesized by the wet method used in the present invention will be given. Of course, this example does not limit the scope of the claims of the present invention.

Table 1 Furthermore, the surface of the silicic acid fine powder synthesized by these wet methods may be treated with an organic substance before use.

When a magnetic toner contains silicic acid fine powder synthesized by such a wet method, a toner that is uniformly and strongly positively charged can be obtained. This effect becomes even more remarkable when combined with a magnetic material synthesized by a wet method. The method of manufacturing the magnetic material using the all-wet method used in the present invention can be modified from the conventionally known method. For example, by neutralizing an aqueous solution of iron sulfate with an alkali, iron is precipitated as a hydroxide or an aqueous solution. At this time, by appropriately combining reaction conditions, black magnetite particles can be obtained. Furthermore, ferrite particles can be obtained by heat treatment of the obtained magnetite. During the process, Z is used for the purpose of adjusting the magnetic percent land.
Metal oxides such as O 2 , Nl 2 , Co 2 , Mg 2 , Cta or Cd may be co-precipitated.

The particle size is preferably within the range of 0.01 to 4s as an average primary particle size. Further, the amount of these magnetic substances applied varies depending on the use of the toner, but it is preferably within the range of 15 to 70% by weight relative to the developer lid.

By incorporating the magnetic material synthesized by such a wet method into a toner together with the silicon 111 ridge powder synthesized by the wet method described in 1 above, a toner that is uniformly charged and positively charged can be obtained. Compared to the case where the silicic acid starch powder synthesized by the wet method is used alone, the silicic acid fine powder synthesized by the wet method is not only stable under high humidity conditions, but also has excellent stability at 4vζ low temperature and low humidity VC. It also exhibits stable appearance and transferability, and provides a clear, high-quality image under any environment. Since the magnetic material synthesized by the wet method is crystallized in a solution, its surface activity is uniform, and the wettability with the resin is good in the field between the resin and the magnetic material when the toner contains 8. , there is little heterogeneity in affinity. For this reason, toner containing a magnetic material synthesized by such a wet method and silicic acid fine powder synthesized by a wet method may cause friction between the toners or between the toner and the sleeve at low temperature and low humidity. Its youthfulness is stable and there is no reduction in image density, fogging, durability deterioration, scattering, etc. caused by toner O charge-up. This phenomenon is caused by the fact that excessive charge is difficult to generate inside the toner, or even if it occurs, it is difficult to form a space charge layer at the interface between the resin and the magnetic material, and direct movement toward the surface occurs quickly. It is considered that the electric charge is adjusted due to the stable volumetric water content of the wet method 7 lyka on the surface.

As the binder resin of the toner of the present invention, styrene such as polystyrene, polyvinyltoluene, p-chlorostyrene, polyvinyltoluene, etc., and monopolymers thereof: styrene-P-chlorostyrene/copolymer, styrene-propylene copolymer, Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, nutyrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene- Styrene/based copolymers such as maleic acid copolymers and styrene-maleic acid ester copolymers: polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyacetate vinyl, polyethylene, polypropylene, polyester, polyurethane, polyamide, Epoxy throat, polyvinyl butyral, polyamide, polyacrylic acid'
@fat, rosin, modified rosin, terpene resin, phenol@fat, shiiphaliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination.

As the coloring material used in the toner of the present invention, conventionally known carbon black, iron black, etc. are used, and all of the conventionally known dyes as positive charge control agents are silicic acid synthesized by the wet method used in the present invention. It can be used in combination with an experiment.

Various dyes such as hapendyldimethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, nigrosine base, nigron hydrochloride, safranin γ and crystalline violet F.

The toner of the present invention can be applied to various conventionally known developing methods. For example, magnetic brush development method, U.S. Patent No. 3,90
No. 9,258: A method using the conductive magnetic toner described in the specification, % A method using the high resistance magnetic toner described in JP-A-53-31136, JP-A-54-421
Publication No. 41, Publication No. 55-18656, Publication No. 54-43
Examples include the method described in Japanese Patent Publication No. 027, a fur brush development method, and an impression development method.

The first characteristic of the positively charged toner constructed in this way is that the silicic acid fine powder synthesized by a wet method is used as a charge 'dt control agent, and a magnetic material synthesized by a wet method is used. In particular, when used as a developing agent for electrophotography, there is no variation in the amount of friction between toner particles.
Moreover, due to the large T-AT, there is no development fog, toner scattering, or toner aggregation that could not be prevented in the past, and based on these, there is no deterioration due to long-term use of the toner, resulting in high quality! (IT can be used for a long period of time.It also has several properties that are of practical importance.One of them is warm violet,
There is almost no decrease in the amount of charge due to environmental changes such as humidity,
It has the surprising characteristic that the transfer efficiency at high humidity is almost the same as that at permanent storage, and there is no drop in temperature due to toner charge build-up at low humidity.

Another feature is that conventional pigments and dyes that control positive charge have selectivity between them and the binding resin used due to their poor dispersibility, and it is not possible to combine them with any resin. However, there is no selectivity between the silicic acid fine powder used in the present invention and the resin, and it can be combined with any resin, allowing a wide range of applicable toner compositions to be selected. For example, in addition to heat fixing toners, the toner can be used in upper chamber landing toner capsule toners.

The basic configuration and features of the present invention have been described above, and the method of the present invention will be specifically explained below based on Examples. However, this K does not limit the embodiment of the present invention in any way. The number of parts in the examples is by weight.

Production Example 1 A magnetic material was produced in the following manner. First, sulfur #1
Iron heptahydrate was dissolved in 1# pure water and placed in an airtight constant temperature reaction tank. At this time, the air in the reaction tank was replaced with N and gas to prevent □P oxidation. The water temperature was heated to 8°°0, and the addition ratio of N5OH (20f□e) was 1.
A sodium hydroxide aqueous solution was added to neutralize the solution.

Heating was continued for 10 hours while passing air through this neutralized aqueous solution. Thereafter, the magnetic particles were obtained by washing with PA1 water and drying at 60"C.The average particle size of the magnetic particles obtained by this process was 0.
．． The BET specific surface area was 9ra"7g at 2μ, and the particle size distribution was sharp. Also, the particle shape was relatively spherical and well-aligned. Under an external magnetic field of 10000e, the particle size was 1500e and σ3 was 84 etsu/ g, (It
was l etma/g.

<Production Example 2> The magnetic material produced in Production Example 1 was heat-treated at 200° C. to obtain a magnetic material B. The BOBET magnetic material thus obtained had a specific surface area of 8 -/-, and the particle size and shape were similar to those of the magnetic particles. Ha under an external magnetic field of 10006@ is 100δ
At e, σl is 4 Q @ttsu/g.

σr was lQemu/g.

<1! ! Example 3> After heating the magnetic material produced in W road side 1 at 500'O for 5 hours, it was reduced through a hydrogen stream to obtain magnetic material C.

The particle size and shape of the magnetic material C did not change to that of the magnetic material. 1
k under the external magnetic field of 0006e (c is 1806@ and σ-
was 86 e+nu/g, and σr was 15 eara/g.

Production Example 4> Addition ratio of NaOH (20V'F P) in Production Example 1
A magnetic material was prepared in the same manner as in Production Example 1, except that sodium hydroxide was added so that the magnetic flux was 1.4.

The average particle size of the nine magnetic materials produced by this AV straining is 0.
At 4x, the value of B1cT specific surface area was found to be 3.0 m2/g. The particle size distribution was sharp, and the shape was similar to that of a sphere. Under an external magnetic field of 1000jje, Ha is 1206e, σ- is 80em+x/g, and σr is 15el
I rarely got llu/g.

Production Example 5> In Production Example 1, add sodium hydroxide so that 20ψe becomes 0.9, and heat at 24 °C while passing air.
Magnetic material E was produced in the same manner as in Production Example 1 except that heating was performed for a certain period of time. The average particle size of the obtained magnetic material E was as fine as 0.1 μm, and the particle size distribution was also ./Yap. BIT specific surface area is 1
Ha under the external magnetic field of @ 1ooOjje at 0m"7g is 2000e and σ1 is 85 emu/g,
σr was 18@mu/g.

・Negative side 6 〉 In TsuJ example 1, make 20■71=2,
The procedure was the same as in Production Example 1 except that the heating temperature of the solution was 85° C. and the air oxidation time was 24 hours, and the magnetic material F was used as a companion. The average particle size of the obtained magnetic material r was 15μ, and the BET specific surface area was 'l-1m'/l.The particle shape was cubic, and the particle size distribution was /yarb.too6e
Kc under external di field was 110ij, σ3 was 75eau+/g, and σf was 20e mu/g.

Production example 7> A dry method magnetic material G was produced in the following manner.

First, ferrous acid heptahydrate was dehydrated with heat to obtain ferrous acid monohydrate. This was fired at 800°C for 1 hour, and this was further fired at 1000°C for 3 hours.9.

At this time, the oxygen partial pressure 1 inside the reaction tube is l o, s volume t
%. Then, the heating was stopped and the mixture was cooled at a cooling rate of 300°C/hr. This fired body was pulverized to a medium size of 200 mesh using an atomizer, and then finely pulverized using a wet attritor. In this case, the slurry was set at 30. As a result, a magnetic material having an average fi2 diameter of 0.6 μm was obtained. Dry at a temperature of 80℃ to adjust the moisture content.
Magnetic material G storehouse. BET of magnetic material obtained in this way
The specific surface area was l 5 m"/g, the particle size distribution was broad, and the particle shape was irregular. Ha under the outer di lift field of 10006e was 150'6*, and σS was 65 e I
n07g, 6 (Vil 0 emu/g).

Production Example 8> The magnetic body Gt obtained in Production Example 7 was treated in the following manner to produce a magnetic body H. First, as a cutting treatment, heating was performed at 500° C. for 1 hour in an air atmosphere. Then H1
The surface was reduced by heating at 300"O in an atmosphere for 2 hours to obtain a magnetic material (2). The average particle size and particle size of the magnetic material thus obtained were 1, and the shape of the degree distribution was that of the magnetic material G. It is about the same level as Bg Ding #:,
The surface area was l g m2/g. 1 o o o 6
Iic under external magnetic field of e is 1656@, σS is 80
em++/g, grFi15eugly-7g and nine.

[Example 1] 1 part of zinc oxide, 20 parts of suderene-ptadiene copolymer, 40 parts by weight of n-butyl methacrylate, 120 parts by weight of toluene, 4 parts by weight of 1 part rose bengal methanol solution The mixture consisting of the following was dispersed and mixed in a ball mill for 6 hours.

This was placed on a 0.05°C thick aluminum plate with a dry cloth thickness of 4
It was coated with a wire bar so that it had a thickness of 0 μm, and the solvent was evaporated with hot air to produce a zinc oxide binder-based photoreceptor, which was then made into a drum. A corona discharge of 15 KV was applied to this photoreceptor to cause a band to spread out over the entire surface, and then an original image was irradiated to form a static i4a image. .

The developer carrier was a stainless steel cylindrical sleeve with external F 5-0 and +. The magnetic flux density on the sleeve surface is 700 gauss, and the distance between the surfaces of the reblade sleeve is 02.

This sleeve rotation magnet fixed (sleeve circumferential speed is the same as that of the drum, rotation direction is opposite) type developing device is connected to the distance f between the photosensitive drum surface and the sleeve surface. ! o, set to 25su, and the sleeve has an AC of 1000H to 1ooov and -
, 150V DC bias was applied.

The above mixed proboscis was kneaded at 150"C using a roll mill, and coarsely pulverized using a cooling bag speed mill. Thereafter, it was finely pulverized using a pulverizer using a jet stream, and 5 to 20 μm using a wind classifier.
I got the toner. In addition, silica synthesized by wet method and Tsubu Seal ER (Japan Silica) are added to the developer with Q, 5w.
+% and mixed with a Henschel mixer to obtain a developer.

An electrostatic latent image was developed using this developer using the above-mentioned developing device, and then the powder image was transferred while irradiating a direct current corona of 17 KV from the back side of the transfer paper to obtain a copied image.

For fixing, use a commercially available plain paper copier (product name, NP-4t) OR
E.

The experiment was carried out using the Gyanon family. The resulting image was clear, had an image density of 1.30, had high resolution, and had no fog at all. Even under the environmental conditions of 30°0185% R)I, the degree of a is as high as 1.25, and the transfer efficiency is excellent.
The repellency against I-wei was also good. Also, 10℃, 1
Even under low humidity conditions of 0% RH, the image density was 1.30, the same as at room temperature and humidity, and no fogging occurred. Regarding durability, normal temperature and humidity, 30″C985%RH, 10″0°1
Image density, sharpness,
However, there was no change at all until 30,000 sheets, and it was in good condition, which I had hoped for.

[Comparative Example 1] A developer was prepared in the same manner as in Example 1, except that the Nigg7-ER fully attached knife was not used, and development, transfer, and fixing were performed in the same manner as in Oi &amp; the density was 0.75. All I could get was a low and unclear image with a lot of fogging. 30℃, 85
Under the environmental conditions of %R1i, the concentration was extremely low at 0.53, making it impossible to put it to practical use.

[Comparative Example 2] A developer was prepared as in Example 9-1 and +IIIj except that the magnetic material G of Production Example 7 was used, and development, transfer, and fixing were performed using the same device. was 0.9. Under the environmental conditions of 30°C and 85% RH, the concentration is 0.85.
, the deterioration was less compared to normal humidity, but at 10℃, 10%
i [! When I got the II image, the image 11 degrees was O, SO
This resulted in low fog and increased fog, making it impractical.

[Example 2] A toner was obtained using the above mixing method according to the method of Example 1.

In addition, silica synthesized by a wet method (Carglenox Hana 1120 Shionogi Pharmaceutical Co., Ltd.) was added at Q, 4wt% to the developer.
In addition, the mixture was mixed using a Henschel mixer to obtain a developer. When this developer was developed, transferred, and fixed using the method of Example 1, the image density was as high as 1.25, and a clear image with no fog was obtained. After being left in a 30"C985%RHC) environment for 1 t month, an i!Il image was obtained, but the S degree was 1.18, a light minute, and there was little scattering in the image.

At 10°C and 10% R1i, it was left for 1 t month and press-fitted! The ii image was 1.30^, and no fogging occurred. ,Durability: normal temperature and humidity, 30'0.85%RH,
10" (3, 1, and 0% RE all performed well up to 30,000 sheets.

[Examples 3-6. Comparative Examples 3 and 4] Table 2 shows the results of evaluation conducted in the same manner as in Example 1, except that the toner materials were changed as shown in Table 2.

Claims (1)

[Claims] 'Magnetic toner containing silicon #l fine powder synthesized by a wet method and a magnetic material synthesized by a wet method.