JPS6018058B2 - Insulating magnetic toner for electrostatic charge development - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. This invention relates to a transferable one-component insulating magnetic toner for electrostatic charge development.

Methods for developing static charges can be roughly divided into liquid development methods, which use a developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, and liquid development methods, which use a developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, and two methods, which use a coloring agent such as carbon black in a natural or synthetic resin. The gascade method uses a developer in which a carrier consisting of iron powder, glass beads, etc. is mixed with a dispersed toner called electrostatic inspection powder, or the magnetic brush method uses a developer consisting only of the toner without mixing a carrier. There are dry developing methods such as the bristle brush method, impression method, powder cloud method, and open chamber method.

The present invention relates to the latter dry developing method, in particular to a developer using a developer consisting only of toner without mixing carrier. In general, in two-component developers, when toner and carrier are mechanically mixed, frictional electricity is generated between the toner and carrier, the carrier is charged with a specific polarity, and the toner is charged with a polarity opposite to that of the carrier. It is possible to develop an electrostatic latent image.

However, toner generally deteriorates after being developed several thousand times due to mechanical abrasion due to shearing and impact forces received during mechanical operations within a developing device. Additionally, high relative humidity adversely affects the triboelectric properties and flow properties of the developer; for example, the triboelectric value of some developers changes with relative humidity. This is not preferable for use in electrophotographic devices. In order to eliminate these drawbacks, a one-component developer containing only toner and containing no carrier has been proposed.

For example, US Pat. No. 3,639,245 describes a so-called conductive magnetic material that combines fine particles of ferromagnetic material such as triiron tetroxide, a thermoplastic resin such as epoxy resin, and conductive carbon black. Toner was disclosed. Although the magnetic toner could eliminate the above-mentioned drawbacks of two-component developers,
On the other hand, since the magnetic toner is conductive, when it is transferred onto plain paper using the most common and easily controllable corona discharge device, the powder image made of the magnetic toner is partially or completely disturbed. Therefore, a good transferred image cannot be obtained.
As a result of research to develop a transferable magnetic toner, the applicant found that the main components are resin and a ferromagnetic material, and the ferromagnetic material is fine particles that have triboelectric charging properties of opposite polarity to the resin. The toner is made up of toner particles that are uniformly dispersed in a resin and formed such that magnetic fine powder is substantially exposed on the surface of the toner particles, and that is electrically insulating as a whole. The developer was completed.

This toner-only developer does not have the disadvantages of conventional two-component developers consisting of toner and carrier, and since the toner as a whole is electrically insulating, it is difficult to print on plain paper, which was a disadvantage of conductive magnetic toner. made transcription possible. When magnetic toner prepared by a general pulverization and granulation method is used in a copying machine that repeatedly performs development and transfer, it has the disadvantage that it causes contamination of the photoreceptor and makes the photoreceptor unusable after a small number of copies. That is,
This causes a decrease in the sensitivity of the photoconductor, a decrease in transfer efficiency, an increase in fog, and the occurrence of transfer blur.

This is because fine particles smaller than 1r generated during pulverization are mixed in the magnetic toner and adhere to the photoreceptor during development. Fine particles of about 1 French or smaller attached to the photoreceptor cannot be removed by cleaning with a bristle brush, and fine particles of 1R or smaller mixed in the magnetic toner are so strong that they cannot be removed by classification operations. attached to the surface of particles. Furthermore, when the magnetic toner remains in a pulverized state, each particle has an irregular shape, and the magnetic powder on the surface of each toner particle protrudes from the resin. Mutual frictional electrification between the magnetic toner particles occurs partially strongly and partially weakly. As a result, the magnetic toner has poor fluidity as a developer, causing a lot of fogging and the like, resulting in only unclear copies. In addition, when the relative humidity is high, the electric charge generated by mutual friction tends to leak, and the fluidity becomes poor, so the image obtained after transfer is a blurred image with low image density and blurring overall. becomes. Another major drawback is that since the magnetic toner contains a filler (magnetic material) in the resin, the melt viscosity is relatively high and the fixability is poor.

In order to improve this fixing property, the purpose of using a resin with a low softening point as a binder can be achieved, but on the other hand, blocking occurs during storage, making it unusable, and the surface of the photoreceptor may be damaged. Problems such as toner filming occur. The present invention has been made to solve the drawbacks of two-component toners and one-component magnetic toners and the various problems mentioned above.

Therefore, the object of the present invention is to develop a static latent image using a one-component developer consisting only of toner that does not require a carrier and does not have the above-mentioned disadvantages, and to produce an image on plain paper without transfer bleed when using a corona discharger. The purpose of the present invention is to provide a one-component developer that can be produced in a number of ways. Another object of the present invention is to provide a one-component developer that does not cause photoreceptor contamination.

Another object of the present invention is to provide a one-component developer with good cleaning properties.

Another object of the present invention is to provide a one-component developer with excellent durability.

Another object of the present invention is to provide a one-component developer that does not cause blocking during storage.

Another object of the present invention is to provide a one-component developer with good fixing properties.

Another object of the present invention is to provide a one-component developer which has excellent image power and gradation, and which can produce clear copies without fogging.

Another object of the present invention is to provide a one-component developer with good green fastness.

Another object of the present invention is to provide a one-component developer with good fluidity.

Another object of the present invention is to provide a one-component developer that is excellent in preventing toner filming on a photoreceptor.

Another object of the present invention is to provide a one-component developer which always has stable triboelectric charging characteristics due to mutual friction during development.

Another object of the present invention is to have a constant and stable V-leak value (a value related to the charge retention property of the toner) in a defined manner, and the V-leak value in parentheses is a value of 50% or less. Our objective is to provide component-based developers.

Another object of the present invention is to provide a one-component developer with excellent pulverizability.

As a result of research aimed at achieving these objectives, it has been discovered that contamination of the photoreceptor of magnetic toner occurs when fine particles with a diameter of about one peak or less are mixed in one toner particle.

For example, if this magnetic toner is treated in a hot air stream at a temperature higher than the softening point of the constituent resin, it is possible to virtually eliminate fine particles with a particle diameter of one peak or less that are electrically or physically attached to the toner surface. I was able to find out. Furthermore, when the magnetic toner contains at least one selected from higher fatty acids, metal soaps, fatty acid amides, higher alcohols, ester lubricants, and hydrocarbon lubricants (hereinafter collectively referred to as additives), the heat treatment step At the same time, the additive contained in the magnetic toner is leached and coated on the surface of the magnetic toner resin.
The fine particles having the particle size lr or less easily fuse to the toner surface softened by heat, and are firmly fixed after cooling. This eliminates photoconductor contamination, resulting in a developer with excellent durability. Furthermore, toner filming on the photoreceptor can be extremely prevented, and the photoreceptor can be used repeatedly. In addition, since the resin surface of the magnetic toner particles is covered with additives, it is possible to use a thermoplastic resin with a low softening point as the binder.
It has been found that it is possible to provide a one-component magnetic toner with excellent fixing properties, and furthermore, due to the above facts, it is possible to prevent blocking at temperatures inside a storage container or a copying machine. Furthermore, since the additives used in the present invention have suitable charging characteristics during development, they can easily provide clear images with excellent gradation, capri, transfer, etc., and can be made spherical by heat treatment. It has been found that the toner particles have very excellent fluidity and cleaning properties. Thermoplastic resins used as binders include styrene resins,
Compared to other resins, epoxy resins and polyester resins (hereinafter referred to as resins used in the present invention) can provide clear copies with excellent image properties. The resin used in the present invention preferably has a softening point (JIS K2531) of 50 to 200 oo, particularly preferably 700 to 150 qo. The resin used in the present invention has excellent pulverizability, and also has the advantage of easily melting and adhering fine particles of one peak or less that are loose between toner particles even during heat treatment.

These resins generate very few particles of IA or less when crushed, and their melt viscosity is lower than other resins during the heat treatment process, so they can be melted sufficiently even with instantaneous heat treatment.
It has the excellent characteristics of melting and adhering the following fine particles and easily making it spherical. That is, the present invention
Magnetic Nato is mainly composed of at least one resin selected from styrene resin, epoxy resin, and polyester resin and ferromagnetic fine particles, and contains metal soap, higher fatty acids, fatty acid amides, and higher alcohols. ,
At least one selected from ester-based lubricants and hydrocarbon-based lubricants is contained in an amount of 0.1 to 65% by weight, preferably 0.2 to 2% by weight, based on the weight of the magnetic toner.
These additives are leached and coated onto the fine particle resin by heat treatment, and the ferromagnetic fine particles are substantially separated from the resin surface on the magnetic toner surface. The particles are exposed to each other, and the mutual friction between the particles generates an electric charge as a toner, and the particles as a whole have an electrical resistance value of 1 to 40 or more.Furthermore, the toner developed on the photoreceptor according to a specified measurement method. This is an insulating magnetic toner for electrostatic latent image development that has a potential attenuation rate (V-leakage) of less than 50%.

The toner manufacturing method is characterized by kneading and pulverizing toner materials and then heat-treating the obtained toner fine particles. The attenuation rate of potential here refers to developing a certain area on zinc oxide photosensitive paper, instantaneously applying light irradiation to the extent that the latent image is almost erased, if not completely, and a toner potential is generated, and then blocked. After that, a translucent electrometer is mounted (point A in FIG. 1, time t) to record the dark decay within a short period of time (within 1 minute). Next, when the entire surface is irradiated at point B, the rock crab latent image is completely erased, so the potential rises to point C and continues to fall thereafter. So ABCD
Once the curve is obtained, draw a parallel curve along the AB curve from point C, and let E be the intersection with time t.The potential V at point E is the case when there is no submerged squadron and the potential attenuation due to light irradiation is almost negligible. This is the initial potential of the toner layer when no voltage is generated. If the potential at the time when 3 minutes have elapsed from L is V2, then V23 x 100% represents the attenuation rate of the potential. The magnetic material that can be used in the present invention is a material that is strongly magnetized in the direction of a magnetic field, is preferably black in color, is well dispersed in a resin, is chemically stable, and has a particle size of 1 MU. Magnetite (triiron tetroxide) is the most preferred because it is desirable that the following fine particles can be easily obtained.

Typical magnetic or magnetizable materials include cobalt,
Metals like iron, nickel; aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc,
Alloys and other mixtures of metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, aluminum oxide, iron oxide, steel oxide, nickel oxide, zinc oxide, titanium oxide, and oxide. Metal compounds including metal oxides such as magnesium; refractory nitrides such as vanadium nitride and chromium nitride; carbides such as tungsten carbide and silica carbide; ferrites and mixtures thereof, etc. can be used. These ferromagnetic materials have an average grain size of 0
．． It is desirable that the amount is about 1 to 1, and the amount contained in the toner is preferably about 50 to 16 parts by weight per 100 parts by weight of the resin component. Particularly preferably resin component 100
90 to 13 parts by weight. As the resin, styrene resin, epoxy resin, and polyester resin are used.

For example, the styrene resin may be a styrene homopolymer or a copolymer of a vinyl monomer and styrene.

Monomers for forming these copolymers include p-
Chlorstyrene, vinylnaphthalene, olefins such as ethylene, propylene, butylene, isobutylene, butadiene; for example, vinyl chloride, vinyl bromide, pinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc. Vinyl esters; for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-acrylate
Esters of Q-methylene aliphatic monocarboxylic acids such as phenyl chloroethyl acrylate, ethyl Q-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dialkylaminoalkyl methacrylate ester: acrylonitrile , methacrylonitrile, acrylamide; for example, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as pinyl methyl ketone, vinyl hexyl ketone, methyl isoprobenyl ketone; for example, N-vinyl N-vinyl compounds such as pyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidene are included, and one or more of these can be copolymerized with a styrene monomer. The resin has a weight average molecular weight of about 3000 or more. Further, a thermoplastic resin obtained by mixing a styrene resin with another resin can also be used as the resin component of the toner according to the present invention.
Other resins that can be mixed with styrenic resins include:
Vinylnaphthalene: For example, vinyl chloride, vinyl bromide,
Vinyl esters such as vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate; for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isoptyl acrylate, dodecyl acrylate, n-octyl acrylate, Emesters of methylene aliphatic monocarboxylic acids such as 2-chloroethyl acrylate, phenyl acrylate, Q-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate: acrylonitrile, methacrylonitrile, acrylamide : Vinyl ethers such as vinyl methyl ether, pinyl isoptynolether, vinyl/lethyl ether, etc. Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isobrobenyl ketone: For example, N-vinyl ether. A homopolymer obtained by polymerizing monomers such as N-vinyl compounds such as ole, N-vinylcal/azole, N-vinylindole, and N-vinylpyrrolidene, or a copolymer obtained by combining two or more of these monomers. Examples include polymerized copolymers and non-vinyl thermoplastic resins such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins, and polyether resins. In addition, as polyester resin,
The diols and dicarboxylic acids that make up the components include the following.

For example, dicarboxylic acids include succinic acid, phthalic acid,
Isophthalic acid, terephthalic acid, maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, trans-hexahydroterephthalic acid, diphenyl-p, p' dicarboxylic acid, benzophenone-4,4-dicarboxylic acid, naphthalene-2,7 -dicarboxylic acid, naphthalene-2/6
Dicarboxylic acid, 1,2-diphenoxychetane-p●p'
-dicarboxylic acid, 1,3-diphenoxypropane-p.
p'-dicarboxylic acid, 1,4 diphenoxybutane-p.
p' dicarboxylic acids and the like.

Examples of diols include ethylene glycol, 1,3-propylene diol, trimethylene glycol, tetramethylene glycol, 1,4-butylene diol, -1,5-
Bentilene glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol,
Nonamethylene glycol, decamethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, p-di(hydroxymethyl)-benzene, cis and transquinitol, hydraquinone di(8-hydroxyethyl)able, 4,4-dihydroxybis Examples include phenyl, pisu(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(hydroxyphenyl)ether, bis(hydroxyphenyl)sulfone, and the like.

Preferred polyhydric alcohols that can be used as branching agents in the polyesters are polyhydric compositions containing about 3 to 15 carbon atoms and about 3 to 8 hydroxyl groups. Typical polyhydric alcohols include bran alcohol, such as glucose,
Fructose, ribose, maltose, and lactose: sugar alcohol anhydrides, monosaccharides and dicarboxylates, and their alkylene oxide derivatives. Preferred examples of these polyhydric alcohols include sorbitol, 1, 2, and
3.6 hexanetetrol, 1,4-sorbitan, bentaerythritol, tribentaerythritol, 1,2
・4-butanetriol, 1,2,5-bentatriol, glycerol, 2-methylpropanetriol, 2
-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, and mixtures thereof. Suitable polycarboxylic acids or esters thereof that can be used as branching agents in the polyester include
It has 6 solid carbon atoms and about 3 to 8 carboxyl groups.

Typical polycarboxylic acids or their esters include 1, 2,
4-benzenetricarboxylic acid, 1.2.5 benzenetricarboxylic acid, 1.2.4-cyclohexanetricarboxylic acid, 2.5.7 naphthalenetricarboxylic acid, 1.2.
4-naphthalene tricamponic acid, 1,2,4-butanetricarponic acid, 1,2,5-hexanetrica'1-bonic acid, 1,3-dicarboxy-2-methylenecarboxylpropane, 1,3-dicarboxyl-2-methyl- 2
-methylenecarboxylpropane, tetra(methylenecarboxyl)methane, 1, 2, 7, 8 octane tetracarboxylic acid, and mixtures thereof. Examples of epoxy resins that can be used in the present invention include the following commercially available representative examples.
Epicote 1002, 10041007, DX-55 (
(manufactured by Shell Chemical Co., Ltd.), Araldite 6084, 707
2, 7097, 6097 (manufactured by CmA), Epotherm CE-80 (manufactured by Mitsubishi Kasei), EPX axis (manufactured by Asahi Denka), AER664667 (manufactured by Asahi Kasei), etc.

The following are representative examples of the higher fatty acids added in the present invention. Mention may be made of lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, ceracoleic acid, etc., and mixtures thereof.

In addition, as commercially available higher fatty acids, the following can be mentioned, for example. F-3, V Yamaichi 2
00 (manufactured by Kawaken Fine Chemicals), cherry blossom, pine, bamboo,
Tsubaki powder stearic acid, beef tallow, NAA222
, 221, (manufactured by NOF), L plate ac S-40
S-90, S-30 8-55, 8-95 10-95
MY-85, MY-95, p-85, p-95 S-
10 S-20 T-S-4, T-S-2, T-D-2
, T-D-4, Power-O-Wax M-80, 8F-Udder, 1-SS (manufactured by Kao Soap Co., Ltd.), etc.

Representative examples of metal soaps that can be used in the present invention include the following. Stearic acid and metal salts such as zinc, cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc.;
Dibasic lead stearate (gabo・Pb(St)2):
Zinc, magnesium, iron, cobalt, copper, oleic acid
Metal salts such as lead and calcium; metal salts such as palmitic acid and aluminum, calcium, lead caprylate, bell caproate, zinc linoleate, cobalt linoleate, calcium ricinoleate, metal salts such as ricinoleic acid and zinc, and cadmium; Mixtures of these and the like can be mentioned.

The fatty acid amide added to the toner of the present invention includes 60
``Fatty acid amide and bis fatty acid amide compounds having a melting point of 0 or more are preferred.

For example, the following can be cited as representative examples. Examples of fatty acid amides include lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, arachic acid amide, behenic acid amide, oleic acid amide, linoleic acid amide, linolenic acid amide, gadolenic acid amide, and erucic acid amide. , ceracoleic acid amide, etc.: Bis fatty acid amides include bislauric acid amide, bismyristic acid amide, bispalmitic acid amide,
Bisstearic acid amide etc.; alkylene pis fatty acid amide, IC, Niji 2, CO-NH-(CH2)5
One NH one.

C.C.I. Day 212 C,. 23CO-NH-(CH2
)4-NH-.

CCIIH233 C, 3 days 27CO-NH-(CH2
)21NH1.

CC18 day 374 C, pan 2, CO-NH-(CH2)
2-NH-.

CC14th 295 C, Phantom 3, CO-NH-(CH2)
2-NH-1.

CC15 days 316 C, 7 days 35CO-NH-CH2-NH-.

CC17 days 357 C, 7 days 35CO-NH-(CH2
)21NH-OCC15 days 318 C23 days 47CO-
NH-CH2-NH-.

CC15th 319. ・〇- 11- 12C2, day 4, CO-NH-CH2-NH-.

CCaH4113. 14C. 7 days 35CO River NH-(CH2)3-NH-.

CC17th 3115. In addition, examples of commercially available fatty acid amide and bis fatty acid amide compounds include the following.

Diamid 200, o-2008, o-200, 0,
Y, W, KN, 日, WN, L-200, 200-bis,
Aamide AP-1, GP-1, Bisamide, Suri/Gutsukusu KN, Lefron F, Kuro/Z-Ace KN, (manufactured by Nippon Hydrogen Co., Ltd.), Aamide S', T, P, C, ○, 0
-3, E, B, methylolamide, bisamide, Blast Flow (manufactured by Nitto Kagaku Co., Ltd.), Aramide HT, 0,
C, Armothrip CP-Paladder, Armothrip-E, Armowax (manufactured by Lion Armor),
Luprole R-C○ (manufactured by ICI), Alflow P-1
H-5 building', V-60 (manufactured by NOF Corporation), Ricaflow-ME-22 (manufactured by Shin Nihon Rikagaku Co., Ltd.), LX-15 (
Kyodo Yakuhin Co., Ltd.), Vyn-Ez6 (Fine Chemical Co., Ltd.), SlipEzeGTVA (Fine Organic Co., Ltd.), Amide 60, Muscle', &, 78, 7L, Bait (all manufactured by Kawaken Fine Chemical Co., Ltd.), Hoechstwax-C
(manufactured by Hoechst Japan), Kemetron Wax-10
0 (manufactured by Nissan Ferrochemical Co.), Varicine 285 (manufactured by Parker Castoil Co.), Noprowax 2-S' (manufactured by Nopko Chemical Co.), Advax 280 (manufactured by Advance Co., Ltd.), Kaohwaxu EB (Kao Soap), and the like.

The higher alcohols added to the present invention may be monohydric alcohols or polyhydric alcohols, and typical examples include lauryl alcohol, myristyl alcohol, /grumyl alcohol, stearyl alcohol, arachyl alcohol/behenyl alcohol. There are many things that can be mentioned.

Incidentally, examples of commercially available higher alcohols include the following. power le call.

&10・20・24 40・42・60・68・80,
80 468 524 624 (manufactured by Kao Soap Co., Ltd.),
Recaflow AS85, 95 Konol 30r, 40N,
10, 1 Blood, 10W, 20, 1 KaD, 201, 2 Hawk,
20, 20r, 2 value, 2 India, 20P, 20PP, 3
0, 3 aids, Ricaflow AC, Ricaflow-AB, (manufactured by New Japan Chemical Co., Ltd.), NAA46 Vinasole, 48 Vinasole, Nitsusan Nu-Loop A (manufactured by NOF Corporation), Stenolu PC (manufactured by DEHYDAG), Gleitmittel L-OH (made in West Germany) etc. As fatty acid esters that can be used in the present invention, esters of fatty acids and monohydric alcohols, esters of fatty acids and polyhydric alcohols, partial esters of fatty acids and polyhydric alcohols, etc. can be used.

In the present invention, these fatty acid esters or partially saponified products thereof may be used alone, or a mixture consisting of a mixture of various fatty acid esters, or fatty acid esters and partially saponified products thereof may be used. It can also be used as a mixture consisting of a mixture of the following. In the present invention, commercially available fatty acid esters or partially saponified products thereof can be effectively used, and many of these commercially available products have the composition of a mixture as described above. Typical commercially available products include, for example, the following. Nitsusan Caster Wax A, Sparm Acetimonogly M (manufactured by Nihon Yushi Co., Ltd.), Diamond Wax (manufactured by Shin Nippon Rika Co., Ltd.), Castor hardness, VLTN-4 (manufactured by 0II Ken Fine Chemical Co., Ltd.), TB121-123 (manufactured by Matsumoto Yushi Co., Ltd.) ), Lytol (manufactured by Sanwa Yushi Co., Ltd.), GIeitmittel (manufactured by West Germany), IxioLG (manufactured by Henkel Japan), Rikemar S-20 Ri S-10F R-20 ○-105 0
LIO B-100, S-300, PS-100, 0
1100 S-900 (manufactured by Riken Vitamin Co., Ltd.), Atmul, Atmos, Homotex, Span (manufactured by Kao Atlas Co., Ltd.), etc. Hydrocarbon thickeners that can be used in the present invention include natural paraffin, microwax, synthetic paraffin, and chlorinated hydrocarbons.

Examples of typical commercially available products include the following. 1350 paraffin, No. 1 paraffin, 1500 micro paraffin (manufactured by Nippon Oil Co., Ltd.), Shell 1350 paraffin wax (manufactured by Shell Sekiyu Co., Ltd.), Santaito A, B, C (manufactured by Oko Chemical Co., Ltd.), Microcrystalline wax (Mobil) GIeitmittel-KO (manufactured by West Germany), ampoule wax (manufactured by Hodogaya Chemical), etc.

The mixing ratio of these additives that can be used in the present invention is 0.1 to 65% by weight, particularly preferably 0.2 to 20% by weight, based on the total weight of the toner. If it is too large, it will be difficult to obtain a good image and suitable conditions for development, and if it is too small, it will be difficult to achieve the initial purpose. Any suitable pigment or dye can be used as a colorant and charge control agent in the one-component toner of the present invention. For example, carbon black, nigrosine dye, aniline blue, calcoal blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue, chloride phthalocyanine blue, mikite green oxalate, lamp black, rose bengal and mixtures thereof. are used, and these are contained in the magnetic toner in such an amount that a clear visible image can be formed by development.The toner is made by heating and kneading a mixture of the magnetic material, resin, additives, and beam pigment using two rolls, etc. This pulverization and granulation method has the following advantages: it is inexpensive to produce, it is very easy to process the powder, and it is also very advantageous in terms of pollution. It has very excellent advantages. It can also be produced by the drying method disclosed in, for example, US Patent No. 991. The surface of the insulating magnetic toner of the present invention is made of Since it is necessary that the resin be exposed from the resin surface, it is necessary to keep this in mind when manufacturing it.

The conditions depend on the types of magnetic material and resin used and the content of the magnetic material, but are also influenced by the manufacturing conditions. In the false mist drying method, the better the dispersion, the better the coating of the magnetic particles with the resin, and the higher the solution concentration, the higher the disk rotation speed, and the lower the blowing temperature, the better the coating of the magnetic particles with the resin. .

If the degree of surface exposure of the magnetic particles becomes excessive, the V leak value will increase, making it impossible to obtain a good transferred image, and the amount of triboelectric charge of each toner particle will also become inappropriate, so care must be taken. The magnetic toner thus obtained does not use a carrier and is one-component, so it does not have the drawbacks of conventional two-component developers, and the magnetic toner particles as a whole are electrically insulating. Clear copies can be obtained on transfer paper, and there is no blocking during toner storage, no contamination of the photoreceptor, no fogging, and a stable developing action simply by replenishing toner. This is an insulating magnetic toner for electrostatic charge development with excellent durability that can be guaranteed.

Next, Examples and Comparative Examples of the present invention will be given, and their effects will be explained.

Parts in Examples and Comparative Examples are by weight unless otherwise specified. Comparative example 1 Himer SBM-73 (styrenic resin manufactured by Sanyo Chemical Co., Ltd.) 5 Foundation part and Mapico Black BL
50 parts of -500 (triiron tetroxide manufactured by Titan Kogyo Co., Ltd.) and Peerless-155 (co.).

After mixing 2.5 parts of carbon black (manufactured by Ambia Carbon Co., Ltd.) and 1 part of Oil Black Shigeru (pigment manufactured by Orient Chemical Co., Ltd.) and applying it to a ball mill for about 2 hours, the mixture was mixed using a heated roll, and after cooling. A toner having an average particle size of about 15 mm was prepared by pulverization, and 0.2% by weight of silica powder (R-972 manufactured by Nippon Aerosil Co., Ltd.) was added as a flow agent to the obtained toner to prepare a sample. Mochiseki Sho 51-26046
The developing device described in the specification was installed in a U-BIX 80 type electrophotographic copying machine manufactured by Roku Konishi Photo Industry Co., Ltd., and the sample was filled with the sample and development and transfer was repeatedly performed on a zinc oxide photoreceptor. As a result, high-density fogging occurred, and after about 10 copies, no image appeared and significant staining occurred on the master. This toner had a V leak value of 16.3% and a specific resistance of 4.5×1 and 40 plows. Similar results were also obtained when the above toner was kneaded and pulverized with the addition of 5% by weight of zinc stearate. Also, the V leak value of this toner is 1
The specific resistance was 7.6×1 and 50%. Comparative example 2 Hymer SBM-7 with 5 foundations and Mapico Black BC-
50,050 parts of Peerless 1,552.5 parts and 1 part of Oil Black were mixed, passed through a pole mill for about 2 hours, thickened using hot rolls, cooled, and pulverized.

Next, the powdered toner was blown into a commercially available experimental spread dryer (Mobil Miner manufactured by Niro Corporation) using an air jet nozzle and instantaneously heat-treated with hot air at 250° C. to prepare a toner. The toner is classified using a classifier to obtain a toner with an average particle height of 15 degrees. % by weight of silica powder was added as a flow agent to prepare a sample. When this toner was filled into the developing device described in Comparative Example 1 and development and transfer was performed repeatedly,
Although a clear image with no transfer bleeding was obtained as an initial image, some fogging occurred after the actual photographing of 200 women, and the sharpness was lower than that of the initial image. Moreover, the surface of the zinc oxide photoreceptor was also slightly stained. The V leak value of this toner was 36%, and the specific resistance was 5.7×1 and 40. Comparative Example 3 35 parts of Epicort 1004 (an epoxy resin manufactured by Shell Chemical Company) and 65 parts of Mapico Black (triiron tetroxide manufactured by Columbia Carbon Company) were dissolved in a mixed solvent of 7 parts of toluene and 3 parts of acetone. After dispersing in a porcelain ball mill for 3 hours to make the solid content 60%, the above-mentioned straining solvent was further added to make the solid content 20%, and the mixture was granulated by a rotating disk spray drying method.

When the thus obtained black toner particles having an average grain height of about 10 ships were developed and transferred using the apparatus described in Comparative Example 1, the image developed on the photosensitive plate was an extremely good gradation image. A large blurring occurred in the transferred image of the object. In addition, the zinc oxide photoreceptor was significantly contaminated. The V leak value of this toner was 75.6%, and the specific resistance was 2.6×1 and 40%. Example 1 Hymer-SBM-73 (styrene resin manufactured by Sanyo Chemical Co., Ltd.) 250 anchor and Mapico Black B
L-500 (triiron tetroxide manufactured by Titanium Kogyo Co., Ltd.) 250 foundation and Peerless 155 (manufactured by Columbia Carbon Co., Ltd.) 125
1 part, 5 parts of zinc stearate, and 5 parts of behenyl alcohol were thoroughly kneaded using a pressure kneader.

After cooling, this was coarsely ground and further finely ground using a jet mill. Next, the pulverized toner was blown into a spray dryer experimental machine using an air jet nozzle and heated to 250 qC.
An insulating magnetic toner was created by instantaneous heat treatment with hot air. The produced toner was processed with an average particle size of 1 using a classifier.
The toner was classified so as to obtain a toner of 5 degrees, and 0.2% by weight of silica powder (R manufactured by Nippon Aerosil Co., Ltd.) was added to the obtained toner.
-972) was added as a flow agent to prepare a sample. When the developing device was attached to a U-BIX200 dish-type electrophotographic copying machine manufactured by Roku Konishi Photo Industry Co., Ltd., and the sample was filled with the sample, development and transfer were performed repeatedly on a zinc oxide photoreceptor. A clear image with no blemishes was obtained. The V leak value was measured and found to be 11.5%, and the specific resistance was 9.7 x 1 and 60 skin. Also, when I printed 50,000 copies using this toner only by replenishing the toner, I was able to obtain clear copies that were no different from the first copy. Even after 50,000 copies, it was expected that hundreds of thousands of copies would be covered.

Example 2: 50 parts of Immer ST-95 (manufactured by Sanyo Chemical Co., Ltd.), 50 parts of Mapico Black BL-500, and Peerless 1552.
When a toner with a formulation of 5 parts stearyl alcohol, 1 part stearyl alcohol, and 2 parts 1500 microparaffin (manufactured by Nippon Oil Co., Ltd.) was processed in the same manner as in Example 1 and development and transfer was repeated, the image remained unchanged from the initial image even after 20,000 copies had been made. A clear copy was obtained.

The V leak value of this toner was 8.9%, and the specific resistance was 4.9 x 1 and 90. Example 3 5 parts of Chemitylene PEB-4 (polyester resin manufactured by Sanyo Chemical Co., Ltd.), 50 parts of Mapico Black BL-100, and Peerless-1552. 1.5 parts of Ikarito and stearic acid amide (manufactured by Ken Fine Chemical Co., Ltd.) and 1 part of Lytolu (manufactured by Sanwa Yushi Co., Ltd.) were treated in the same manner as in Example 1, and a selenium photoreceptor was used instead of the zinc oxide photoreceptor. When it was installed in a U-BIX 200 plate-type copying machine and developed and transferred, copies were obtained that were as clear as the initial images even after copying 50,000 copies.

The V leak value of this toner is 6.7%, and the specific resistance is 1.
．． It was 5 x 1 and 60 pieces. Example 4 25 parts of Himer UP-110 (polyester resin manufactured by Sanyo Chemical Co., Ltd.), 25 parts of Picolastic E-100 (manufactured by Esso Standard Co., Ltd.), and Mapico Black BL-50050
A toner containing 2 parts of Peerless-1552.5 parts, 2 parts of NAAm222 (manufactured by NOF Corporation), and 1 part of Oil Black BS (manufactured by Orient Chemical Co., Ltd.) was treated in the same manner as in Example 1, and development and transfer were repeated. Even after copying 20,000 copies, clear copies that were as good as the initial images were obtained.

Further, the V leak value of this toner was 151%, and the comparable resistance was 2.1×1 and 50%. Example 5 45 parts of Epicort 1004 (epoxy resin manufactured by Shelley B Gakusha), 55 parts of Mapico Platsk BL-50005, 2.5 parts of Peerless 1552.5 parts, and 3 parts of Bisamide (manufactured by Nippon Hydrogen Industry Co., Ltd.) were combined with Kemal B-100 (Riken Vitamin). oil) 1
When the same process as in Example 1 was carried out on the toner with the same formulation as in Example 1 and development and transfer was repeated, 50,000 sheets were printed. The specific resistance is 4.3×
There were 1 and 50 enemies.

Example 6 Epicoat 1004 (manufactured by Shell Chemical Co., Ltd.) 4 anchors, Mapico Black BL-1006 base, 2 parts of Oil Black BS, 6 parts of zinc stearate, and 2 parts of stearic acid were treated in the same manner as in Example 1, When development and transfer were repeated, no change in the image was observed even after 10,000 copies.

Further, the V leak value of this toner was 43.3%, and the specific resistance was 1.7×1 and 40.

[Brief explanation of the drawing]

The drawing shows the relationship between time and toner layer potential when measuring the decay rate of potential. , t2 is time, and V, , V2 is the toner layer potential. Figure 1

Claims (1)

[Claims] 1. A magnetic toner mainly composed of at least one resin selected from styrene resins, epoxy resins, and polyester resins and ferromagnetic fine powder, which contains metal soap, higher fatty acids, fatty acid amides, and higher alcohols. , a hydrocarbon lubricant, and an ester lubricant, and by heat-treating the toner fine particles at a temperature higher than the softening point of the resin, the toner surface is coated with the compound. 1. A one-component insulating toner for electrostatic charge development, characterized in that the toner is coated and spherical with substantially no fine particles of 1 μm or less, and the fine particles as a whole are electrically insulating.