JPH01145662A - Toner - Google Patents

Abstract

PURPOSE:To obtain a toner having superior transferability on a sleeve, not causing scattering and also having superior fixability by using at least org. magnetic powder and a binding resin. CONSTITUTION:A toner is composed essentially of an org. magnetic body includ ing org. magnetic powder and a binding resin. The org. magnetic body has superior dispersibility in the binding resin, can provide weak magnetism to the toner and may be a known org. magnetic body such as iron (II, III)- polycarbene, preferably PPH.FeSO4. The binding resin may be acrylic resin having polar groups such as carboxyl, hydroxyl, glycidyl or amino groups. The toner has satisfactory fixability and does not cause scattering by which fogging, deterioration of image quality, unstableness of image density and con tamination in a copying machine are caused.

Description

[Detailed description of the invention] Industrial applications The present invention relates to toner used in electrophotographic reproduction.

In prior art electrophotographic reproduction methods, the electrostatic latent image is developed and made visible by a developer.

Currently, the mainstream development method is magnetic brush development, and the developer used in this method is a two-component developer that uses a combination of toner and a carrier containing magnetic powder, or a toner containing magnetic powder. One-component systems are known.

In the magnetic brush development method, the toner is charged by frictional charging, etc., and is carried to the development area using the magnetic force applied to the magnetic powder, where a copy image is formed through development of the electrostatic latent image, toner transfer, and fixation. be done.

One of the basic characteristics for evaluating toner is its scattering property. When the toner has a large scattering property, various problems occur such as fogging, poor image quality, instability of image density, and contamination inside the copying machine due to the scattered toner.

A possible cause of the toner scattering is that the toner has a wide charge distribution and low charge components are not restrained by electrostatic attraction with the carrier on the sleeve, so that the toner scatters.

As a means to prevent the toner from scattering, it is possible to use the magnetic field formed by the magnetic roller between the sleeve and the photoreceptor to restrain the toner by magnetic force. A toner containing an inorganic magnetic powder, for example a -component magnetic toner, is
It is considered that it is effective to use it as a toner for component-based developers.

However, it is difficult to uniformly disperse and contain inorganic magnetic powder in toner, and it is not possible to effectively prevent toner scattering, and copied images of toner containing inorganic magnetic powder have poor fixability. There is a problem that the image quality is poor and the image density is low. The problem becomes more serious as the amount of inorganic magnetic powder increases.

As magnetic materials, metals such as iron, cobalt, and nickel, alloys of these metals with other metals, and inorganic magnetic materials such as metal oxides are well known and used. These inorganic magnetic materials have the advantage of having excellent magnetic properties and being stable, but they also have the problem of being inherently heavy, hard, and poor in processability.

Problems to be Solved by the Invention The present invention improves the above-mentioned problems and eliminates toner scattering, which causes capri formation, poor image quality, instability of image density, and contamination in the copying machine due to scattered toner. , the purpose is to provide a toner with good fixing properties.

Means for solving the problem, namely, the present invention relates to a toner containing organic magnetic powder.

The toner of the present invention comprises at least organic magnetic powder and a binder resin.

In the present invention, organic magnetic materials include organic compounds (including organometallic complexes) and polymer compounds (including organometallic complexes) that are magnetized with a strength according to an external magnetic field due to a specific chemical structure and exhibit paramagnetic or ferromagnetic magnetization characteristics. (including polymer organometallic complexes).

Specifically, the organic magnetic material is iron (■, If)-poly(2
,6-pyridine dimedylidene nitrilohexamethylene nitrilomethylizonato (poly(2,6-pyridi
ned imethy I 1denen it r
i Iohexamethy 1enen it r
i lomeLhylidenaLo) I ron(
11, II [X hereinafter referred to as "PLL/FeSO4"]
, polycarbene, and the like can be used, and P P H ·FeSO4 is particularly preferred.

P P H・FeS O4 is a combination of 2,6-pyridinecarparaldehyde and 1. It can be easily obtained by dehydrating and condensing f3-hexanediamine and reacting with FeSO4.78IO, and F, L ons a
ndK, V, MarLine: J, Aa+, CI-
Iem,Soc,,79. 2 733 (1957)
Or T, Sugano, M, KinoshiLa,
1.5hirotani and K, Ohno:
5solid 5tateComm,,45.99
(1983), etc. can be referred to. The magnetic properties of the organic magnetic material P P H FeSO4 are such that the magnetic flux density Bm in an applied magnetic field of 10000 e is approximately 4201
The amount of magnetization σ is approximately 3°5 emu/g, and the residual magnetization is approximately 7. I.G.
Hit the degree.

Since the organic magnetic material has excellent dispersibility with the binder resin and can impart weak magnetism to the toner, it is possible to obtain a toner that is free from scattering and has excellent fixing performance.

In the present invention, it is effective to contain the organic magnetic powder so that it is present in a large amount in the surface layer of the toner.

When the toner of the present invention is used as a one-component magnetic toner, an inorganic magnetic material may be blended together with an organic magnetic material.

Inorganic magnetic materials include metals such as iron, nickel, and cobalt;
These metals and zinc, antimony, aluminum, lead,
Alloys or mixtures with metals such as tin, bismuth, beryllium, manganese, selenium, tungsten, zirconium, and vanadium, metal oxides such as iron oxide, titanium oxide, and magnesium oxide, nitrides such as chromium nitride and vanadium nitride, and silicon carbide. , mixtures with carbides such as tungsten carbide, ferromagnetic ferrite, and mixtures thereof.

The amount used is 50 parts by weight per 100 parts by weight of the seam binder resin.
Parts by weight. This is because if the amount exceeds 50 parts by weight, toner fixing properties will be poor, and the binding force to the magnetic roll will be strong, resulting in poor developability.

The binder resin used in the present invention includes acrylic resins having polar groups such as carboxyl groups, hydroxyl groups, glycidyl groups, and amino groups, and acrylic acid resins such as methacrylic acid, acrylic acid, maleic acid, and itaconic acid. Monomers; Monomers with hydroxyl groups such as hydroxy polypropylene monomethacrylate and polyethylene glycol monomethacrylate; Monomers with amino groups such as dimedylaminoedyl methacrylate; Copolymerization of glycidyl methacrylate, etc. with lower alkyl acrylate and/or styrene. I can name codfish.

It is also obtained by condensing a polyester resin, such as a polyol such as ethylene glycol, triethylene glycol, 1,2-propylene glycol, or 1,4-butanediol, with a dicarboxylic acid, such as maleic acid, itaconic acid, malonic acid, etc. Examples include polyester resins and thermoplastic resins such as epoxy resins.

These resins may be three-dimensionally crosslinked to adjust their viscosity.

Furthermore, in addition to the above-mentioned resins, vinyl resins, rosin-modified phenol-formalin resins, cellulose resins, polyether resins, silicone resins, fluororesins, etc. can be mentioned.

The toner of the present invention is colored by adding a black pigment such as carbon black, aniline black, lamp black, or aniline black. The appropriate amount of these pigments to be used is 1 to 20% by weight, more preferably 3 to 7% by weight, based on the total amount of the toner.

The toner of the present invention may further contain other additives, such as a charge control agent and an anti-offset agent.

Typical charge control agents that impart positive chargeability to the toner include basic dyes such as nigrosine-based ura-soluble dyes and crystal violet, and typical charge control agents that impart negative chargeability to the toner include: Examples include metal complex dyes such as baratin dyes and orazole dyes.

Such dyes can be used alone, making use of their function as a coloring agent in addition to their ability to control charge. Of course, it may be used in combination with the above pigments.

The amount of charge control agent used is 1 to 20% by weight of the total amount of toner.
More preferably, 3 to 7% by weight is appropriate.

The toner of the present invention may contain an anti-offset agent in order to improve fixing properties. Examples of the anti-offset agent include wax, low molecular weight polypropylene, polyethylene, and oxidized polypropylene and polyethylene.

A fluidizing agent may be added and mixed (externally added) to the toner of the present invention in order to improve fluidity. Silica as a fluidizing agent,
Examples include aluminum oxide, titanium oxide, silica/aluminum oxide mixture, and silica/titanium oxide mixture.

The toner of the present invention is produced by thoroughly mixing a composition obtained by mixing the above-mentioned main components, and then kneading the mixture until it becomes sufficiently uniform, cooling it, and pulverizing it with a pulverizer such as a jet pulverizer. , coarse powder and fine powder are removed by classification, and the average particle size is 5.
Obtain ~20 μm toner. If it is smaller than 5 μm, even the toner of the present invention may be scattered, and if it is larger than 20 μm, the image quality will be poor.

When the toner of the present invention is used as a two-component developer by blending it with an appropriate magnetic carrier, the magnetic carrier may include metals such as iron, nickel, and cobalt, these metals and zinc,
Alloys or mixtures with metals such as antimony, alumina, lead, tin, bismuth, beryllium, manganese, selenium, tungsten, zirconium, vanadium, metal oxides such as iron oxide, titanium oxide, magnesium oxide, chromium nitride, vanadium nitride Examples include nitrides such as silicon carbide, mixtures with carbides such as tungsten carbide, ferromagnetic ferrite, and mixtures thereof. These carriers include binder type (micro) carriers, magnetic particle coated carriers, resins, etc. It may be used in various embodiments such as particle coated carriers.

The average particle size of the carrier is 20 to 100 μm, preferably 3
A thickness of 0 to 80 μm is desirable. If the average particle size is less than 20 μm, carrier adhesion to the electrostatic latent image carrier tends to occur, and control of the amount of charge becomes difficult.

Moreover, if the average particle diameter exceeds 100 μm, clear images cannot be obtained due to generation of carrier streaks, and image quality deteriorates.

The composition ratio of the developer is 5 to 25% by weight of toner. If it is more than 25% by weight, the amount of charge per toner may decrease and fog may occur, and if it is less than 5% by weight, the amount of charge per toner will increase, leading to a decrease in image density. be.

Synthesis example of organic magnetic material P P I-1 FeSO4 Equimolar amounts of 2.6-pyricine dicarbaldehyde and 1.6-
Hexanediamine was dehydrated and condensed in hot ethanol, and the ligand [Cl31117N3]n (white powder, 'rm~I
40° C., hereinafter abbreviated as P P II). Next, this P P H was reacted with FeSO4.7 tl, O in hot water at 80-90° C. under a nitrogen stream to obtain a dark red solid. The obtained substance was dried in a vacuum desiccator for 72 hours to obtain the desired organic magnetic material.

Identification was based on elemental analysis, infrared absorption spectrum, and far-infrared absorption spectrum.

Elemental analysis value calculation value (%): C, 45, 21; N, 12, 17; Fe
, 8.09 Actual value (%): C, 43,95; N, 12.
05; re, 7.98 Toner production example 1 [(-) Chargeable toner (toner A)] Components Parts by weight Polyester resin 262 (Softening point, 1
30°C; Glass transition point, 60''C) Carbon black 5 (manufactured by Mitsubishi Chemical Corporation, MA#8
) - Organic magnetic material P P HFeS 04 10 The above materials were thoroughly mixed in a ball mill, and then kneaded on three rolls heated to 140°C. After the kneaded mixture was left to cool, it was coarsely pulverized using a feather mill, and further finely pulverized using a die''/tomill.Next, it was air classified to obtain a fine powder with an average particle size of 13 μm (toner A).

Toner Production Example 2 [(+) Chargeable Toner (Toner I3)] Toner B was produced using the same method as Production Example I with the following composition.

Ingredients: 1 part -・
Styrene-n-butyl summer 00 methacrylate resin (softening point, 132°C; glass transition point, 60”C)・Carbon black 5 (manufactured by Mitsubishi Kasei Corporation, MA#8) ・Nigrosine dye 3 (manufactured by Orient Chemical Co., Ltd., Bontron N -01)・Organic magnetic material P
P I-I FeS Oa l O polyester resin! 00 (softening point, 1
23°C Nigaras transition point, 65°C AV23.011V40
)・Inorganic magnetic powder 500 (manufactured by Toda Kogyo Co., Ltd., EPT-1000)・Carbon black 2 (manufactured by Mitsubishi Kasei Co., Ltd., MA#8) The above materials were thoroughly mixed and pulverized using a Henschel mixer, and then the cylinder part was heated to 180°C and the cylinder head Part 170
The mixture was melted and kneaded using an extrusion kneader set at ℃. After cooling, the kneaded material was finely pulverized using a jet mill and then classified using a classifier to obtain a magnetic carrier with an average particle size of 55 μm.

Carrier production example 2 Bisphenol type polyester resin (softening point: 123°C, glass transition point: 65°C; AV, 21) was added to a toluene solution for 2 hours.
%, and then the core material ferrite F'-
250111 (average particle size 5 (lczm; electrical resistance 3.5
0XIO'Ωcm; [manufactured by E1 Hon Tetsuko Co., Ltd.] 3,000 parts by weight was sprayed using Spiller Coater 5P-40 (manufactured by Kaida Seiko Co., Ltd.) at a pressure of 3.5 ky/cm and a spray amount of 40 g/min.
The particles were treated at a temperature of 50° C. for 120 minutes, and aggregates were removed using a sieve (sieve opening: 105 μm) to obtain a coated carrier (a).

City Iki coat carrier (a) 400 parts by weight and Fe-Zn
Ferrite fine particles MFP-2 (electrical resistance 5.2I
4 parts by weight of [0''ΩciH'rDK Co., Ltd.] was heated at 110 rotations using Ongmill ΔM-20F (Hosoka Micron Co., Ltd.).
Aggregates were removed from the carrier particles obtained by treatment at 0 Orp+ for 40 minutes using a sieve (sieve opening: 105 μl 11) to obtain a carrier.

Carrier production example 3 Bisphenol type polyester resin (softening point: 123°C, glass transition point: 65°C: AV21, Otl V 43, M
Nia, 600, Mw: I88.400) was finely pulverized with a jet pulverizer, and then classified with an air classifier to obtain an average particle size of 2.
．． Polymer particles of 8 μm were obtained.

Next, iron powder TEFV 250/400 (manufactured by Nippon Tetsuko Co., Ltd.,
Average particle size 50Bm, electrical resistance 3.2x I OLIΩ・
cl, true specific gravity 7.6) I, 000 parts by weight, and 3 parts by weight of the above polymer particles were mixed at 10.00 Orpm for 5 minutes using a multi-blender mill (manufactured by Nippon Seiki Seisakusho Co., Ltd.), and then placed in an autoclave TAS equipped with a stirrer. -1 (manufactured by Pressure Glass Industry Co., Ltd.). This was carried out under nitrogen pressure (30
kg/ax, stirring at 200°C for 3 hours (700r
pm) L, the obtained particles were sieved (opening 105 μm)
A coated carrier was obtained by removing aggregates using
).

Example 1 The toner obtained in Toner Production Example 1 and the carrier obtained in Carrier Production Example 1 were combined to obtain a developer with a toner mixing ratio of 10 wt %.

When the mixing time of this developer is 3.1O130 minutes, the toner band 7tfIft is -14.2 and -1, respectively.
It was 4.1, -14.1 μC/g. It can be seen that the charging rise is fast and stable.

In addition, this developer was stored at 35°C and 85% Rti under high humidity for 24 hours.
Toner charge amount after storage for a time is -14.3μC/g
Met. It can be seen that the environmental resistance of this toner is f2.

Next, using this developer, a (+) chargeable Sc photoreceptor,
Using a copying machine equipped with a heated qualitative roll coated with Teflon, a (+) polar electrostatic charge image was developed by a magnetic brush development method, and 60,000 copies were made continuously. As a result, high-quality images with excellent initial image quality and no density unevenness, toner fog, or toner scattering were obtained, and this was maintained even after 60,000 copies were made. When the carrier in the developer was investigated, so-called spent toner was not observed. Further investigation of the photoreceptor revealed that no filming had occurred.

The above results are summarized in Table 1.

In addition, in Table 1, ◎, ○, △, × described as image evaluation
◎ represents a comprehensive evaluation of the image, respectively: ◎: Appropriate image density, good fine line reproducibility, no fog, and gradation reproduction of 10 steps or more.

O: Appropriate image density, lack of stability in fine line reproduction, no fog, and gradation reproduction of 8 steps or more.

△: Image density is not stable, fine line reproducibility is poor, fogging often occurs, and the image quality is poor. 4 reproduction 6 steps or less.

X: Large fluctuations in image density, lack of fine line reproducibility, fogging, and gradation reproduction of 4 levels or less.

means.

The initial image is an evaluation of the image quality obtained at the beginning of the printing durability test, and "good" indicates that a high-quality image without density unevenness, toner fog, toner scattering, etc. is obtained.

Image quality is an evaluation of the image quality after printing, and "stable" means
This shows that the image density after 60,000 sheets of printing remains unchanged as it was at the initial stage.

Example 2 A developer was prepared in the same manner as in Example 1, except that the toner produced in Toner Production Example 2 was used and a (-) chargeable multilayer organic photoreceptor was used as the photoreceptor. was evaluated.

The results are summarized in Table 1.

Example 3 A toner was produced in the same manner as in Toner Production Example 2, except that the blending ratio of the organic magnetic powder was 100 parts by weight.

The toner was evaluated in the same manner as in Example 1, using only the obtained toner without using the carrier.

The results are summarized in Table I.

Example 4 A toner was prepared and evaluated in the same manner as in Example 3, except that the blending ratio of the organic magnetic powder was 300 parts by weight.

The results are summarized in Table 1.

In Example 3, the inorganic magnetic material EPT-1000
Example 3 except that 2 parts by weight of (manufactured by Toda Kogyo Co., Ltd.) was added.
A toner was prepared and evaluated in the same manner.

The results are summarized in Table 1.

Example 6 In Example 1, the blending ratio of the organic magnetic material was 2 parts by weight,
Toner and developer were prepared and evaluated in the same manner as in Example 1, except that the magnetic particle coated carrier obtained in Carrier Production Example 2 was used.

Example 7 Toner and developer were prepared in the same manner as in Example 1, except that in Example 2, the blending ratio of the organic magnetic material was 0.5 parts by weight, and the resin particle coated carrier obtained in Carrier Production Example 3 was used. prepared and evaluated.

The results are shown in Table 1.

Comparative Example 1 A developer with a toner mixing ratio of 10 wt % was obtained in the same manner as in Example 1. However, the toner used here does not contain any organic magnetic material in the toner manufacturing example, the carrier is the one obtained in carrier manufacturing example 1, and the mixing time of this developer is 3, 10130 The toner charge amount in minutes is -14, 2, -14, 3, -14, 2μ, respectively.
C/g.

Further, after this developer was stored for 24 hours at 35° C. and 85% RH under high humidity, the toner charge amount was 13°8 μC/y.

Next, using this developer, a (+) chargeable Se photoreceptor,
Using a copying machine equipped with a Teflon-coated heating fixing roll, an attempt was made to develop a (+) polar electrostatic charge image by a magnetic brush development method and to make continuous copies of 60,000 sheets.

As a result, some toner fog was observed in the background area from the beginning. When I took out the developer stock and looked at it, I found that the toner mixture was scattered around the sleeve. Furthermore, the inside of the copier was also dirty with scattered toner.

The results are shown in Table 1.

Comparative Example 2 Inorganic magnetic material EP was used instead of organic magnetic material in Example 1.
Toner and developer were prepared and evaluated in the same manner as in Example 1, except that T-1000 (manufactured by Toda Kogyo Co., Ltd.) was blended in an amount of 0 parts by weight.

Example 3 In Comparative Example 2, a toner was prepared using 50 parts by weight of EPT-1000, and the toner was evaluated without using a carrier.

The results are summarized in Table 1.

Comparative Example 4 In Comparative Example 2, inorganic magnetic material MFP-2 (manufactured by TDK)
A toner was prepared by using 10 parts by weight of the following, and the toner was evaluated without using a carrier.

The results are summarized in Table 1.

Effects of the Invention The toner containing the organic magnetic powder of the present invention has excellent transportability on a sleeve, is free from toner scattering, and has excellent regularity.

Patent applicant: Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. Toner containing organic magnetic powder.