JP3420304B2 - Two-component magnetic developer toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Related to spent two-component magnetic developer toner
In more detail, the charge control agent having a migration property in the toner particles.
, And there is no toner scattering during development,
In addition, transfer is performed efficiently, and a high-density image can be formed.
In addition, toner and carrier life have been extended
About. [0002] 2. Description of the Related Art An electrostatic image formed on an electrophotographic photosensitive member
So-called two-component magnetic development as a developer for developing
Agents are widely used. [0003] The two-component magnetic developer is composed of iron powder, ferrous powder.
Magnetic carrier comprising particles and colored resin composition
And a composition with a visible toner.
During development, the magnetic carrier and toner are mixed
As a result, the toner particles are charged to a certain polarity, and this
Convey the mixture to the photoreceptor in the form of a magnetic brush and
The surface of the photoconductor is rubbed with a magnetic brush, and the charged toner is applied to the surface of the photoconductor.
A visible image is formed by adsorbing and holding the surface charge image. [0004] A constant polarity due to frictional charging of toner particles
In order to control, it is necessary to include a charge control agent in the toner particles.
Is generally used, and for negatively chargeable toners,
Negative charge control agents such as salt dyes and metal complexes of oxycarboxylic acids
(For example, JP-A-3-67268).
For chargeable toners, oil-soluble dyes such as nigrosine and
Positive charge control agents such as amine type control agents (for example,
-106249). As a toner for a two-component magnetic developer, magnetic toner
The use of toner has long been known, for example,
JP-A-56-106249 and JP-A-59-1
Japanese Patent No. 62563 discloses that a magnetic powder is contained in a toner.
It is described that a toner containing magnetic powder is used.
Japanese Patent Application Laid-Open No. 3-67268 discloses that a silica powder is used as a toner base.
The magnetic toner externally added toner mixed with powder and magnetic powder is described.
Have been. [0006] The two-component magnetic developer comprises:
In the early stage of mixing and using the magnetic carrier and toner
In other words, even if it shows satisfactory charging performance,
Charging performance deteriorates due to the generation of toner (toner).
It is known that life is shortened. The spent (toner) is a magnetic carrier.
The toner component adheres and deposits on the surface of the
And the surface of the magnetic carrier is close to that of the toner
, The triboelectric train approaches,
Electric performance cannot be obtained. Thus, spent occurs
The magnetic carrier is discarded and a new magnetic carrier
Inconvenience of having to exchange
You. [0008] Accordingly, an object of the present invention is to improve the spent resistance.
Excellent durability and durability, and extended life of toner and carrier
To provide a two-component magnetic developer. It is another object of the present invention to provide
Contains no neutral charge control agent, toner scatters during development
CCA (Charge control) that can increase apparent development sensitivity without
) -Free (CCA-less) two-component magnetic developer
To provide toner. Still another object of the present invention is to provide a transferable charging system.
Despite not containing the agent, from the photoreceptor surface to paper
CCA-less two-component system for efficient transfer of DNA
Providing an imaging agent. [0011] According to the present invention, there are provided two components.
Resin medium for fixing in negatively charged toner for magnetic developer
Is a copolymer resin or resin composition having an anionic polar group
And the toner is a resin medium on the surface and inside of the toner.
Containing magnetic powder within 8 parts by weight per 100 parts by weight of
Of the magnetic powders, those having a dusting treatment applied to the toner surface have a particle diameter of 0.
3 to 1.5 parts by weight and added inside the toner
Is at least 0.3 parts by weight, and the toner is
The wavelength of the extracted solution extracted with
Absorbance at 280 to 350 nm
A two-component magnetic developer
Provided. [0012] The present inventors have prevented the occurrence of spent in toner.
The following interesting facts were discovered during the research
did. FIG. 1 of the accompanying drawings is used for developing a positively charged image.
Charge control agent among conventional two-component magnetic developer toners
A chromium complex dye (2: 1 type)
Wavelength 400-700n of extract extracted with methanol
FIG. 2 is an absorbance curve at m.
Wave of Methanol Extract of Toner Using Metal Tylate Complex
It is an absorbance curve in length 280-350 nm. [0014] According to these results, all the extracts were stripped.
The characteristic absorption peak based on the electric control agent is shown.
The surface of the toner particles contains a very high concentration of charge control agent.
That means. This is because the charge control agent
Transfer to the surface of toner particles
The idea of controlling the charge due to triboelectric charging by
It matches well. FIG. 3 shows the toner used in the measurement of FIG.
-As a two-component magnetic developer
The same applies to methano
The wavelength of the extract is 400 to 700 nm
Is a measurement of the absorbance curve. According to the measurement results, the carrier surface
Also the charge control agent adheres and precipitates at a high concentration,
Charging failure due to toner resin
Charging, not just filming of the carrier surface
Surprising that the transfer of the control agent to the carrier surface
The facts became clear. This fact is described with reference to FIGS.
It becomes even more apparent. 4 and 5 show the charge control agent.
Mixture of charged toner and magnetic carrier and charging
Mixture of toner and magnetic carrier without control agent
When mixing, the relationship between mixing time and spent amount
Plots the relationship between mixing time and charge amount
is there. According to these results, the inclusion of the charge control agent
Toner has a higher spent amount than toner not containing
The fact that the decrease in charge amount is large is clear.
You. FIG. 6 shows a carrier to which spent is attached.
Between the spent amount of the toner and the charge control agent in the spent toner
The relationship was measured. In FIG. 6, the dotted line indicates the toner prescription.
Is a plot of predicted values calculated from. this
According to the results, the charge control agent was in the early stage of spent generation.
Fact that it selectively migrates and adheres to the carrier surface
Becomes clear. FIGS. 5 and 6 show no toner supply.
This is a result in a closed system, and replacement of toner in the copying machine is
In some cases, the difference due to the presence or absence of the charge control agent is further expanded
Can be expected. FIG. 7 is a graph showing the individual components in the toner.
And the mixing time when mixing the magnetic carrier
The relationship with the amount of spent is shown. According to this result,
The charge control agent is overwhelmingly of all components in the toner.
A component that migrates to the rear surface and tends to generate spent
It became clear. From the above, the conventional two-component magnetic development
Charging failure caused by spent in the agent is explained in FIG.
As shown in the figure, in the early stage of mixed use, the carrier is
+ And toner were negatively charged, but the carrier table
Spent to which the charge control agent is selectively transferred is formed on the surface
The spent layer was charged negatively and positively charged
It can be explained that the opposite polarity toner is formed. In the present invention, the charging of the magnetic carrier surface is performed.
To prevent the transfer of the control agent, the transfer zone to the toner particles
The internal addition or blending of the electric control agent was canceled. Accompanying this
Thus, the toner of the present invention has the following absorbance curve as shown in FIG.
When extracted with methanol, this methanol extract
Has an absorption peak at a wavelength of 400 to 700 nm.
Absence or, if present, virtually zero absorbance
is there. As shown in the absorbance curve of FIG.
And measure the absorbance at 280-350nm
Also, there is no absorption peak and the absorbance is substantially zero. This
This suppresses the transfer of the charge control agent to the carrier surface
The first feature of the present invention is that the spent resistance is improved.
It is a sign. By the way, as shown in FIG.
For toner not contained, a toner containing a charge control agent
In this case, the charge amount becomes insufficient. In the present invention,
To prevent this, an anion is used as the fixing resin medium.
Using a copolymerizable resin or resin composition having a polar group
You. By using this resin or resin composition, development
As a result, the minimum necessary charge controllability of frictional charging can be obtained. The anionic polar group has a charge control property on the toner.
Which is bound to the resin skeleton
As a result, there is no transfer to the toner particle surface,
Coulomb force between toner particles and carrier in brush
The weaker the connection, especially the faster the copying,
Toner scattering becomes remarkable, and this causes
Defects such as increased fog density of dye and copy
It is. In the present invention, in order to prevent this, the toner
8 parts by weight per 100 parts by weight of resin medium on the surface and inside
Including magnetic powder within. Inside and table of toner particles
As magnetic powder is added to the surface, toner-to-carrier
Magnetic force of toner to carrier in addition to the magnetic force
This prevents toner scattering. In the present invention, while preventing toner scattering,
Thus, the apparent sensitivity at the time of development can be increased is a remarkable feature of the present invention.
Is one of the major advantages. That is, charging per toner particle
The smaller the amount, the more toner particles adhere to the electrostatic latent image with a constant charge amount
As the number of children increases, the apparent development sensitivity increases. However, the addition amount of the magnetic powder is
If the total exceeds 8 parts by weight per 100 parts by weight, the electrostatic latent
The amount of toner adhering to the image decreases, and the image density decreases.
Therefore, it is essential to add within this limit. In the present invention, a part of the magnetic powder is externally added.
It is also essential. Magnetism externally added to toner particles
The powder is prepared by polishing the surface of the magnetic carrier and
Excellent durability of developer due to removal of rumming toner
To improve. Further, the toner particles can be added to each other by the externally added magnetic powder.
Reduces the adhesion between toner and photoreceptor, causing toner
The shooting efficiency can be significantly improved. In the present invention, the magnetic material added to the toner
Powder that has been spray-coated on the toner surface (external
Amount) is 0.3 to 1.5 parts by weight and the toner
At least 0.3 parts by weight added to
It is also important that If the amount of external magnetic powder is larger than the above range, the
Chargeability of photoreceptor due to reduction of image density or excessive shaving of photoreceptor
Is unfavorably caused. In addition,
When the added amount is below the above range, the above-described effect of the present invention is achieved.
Not done. [0031] BEST MODE FOR CARRYING OUT THE INVENTION [Resin Medium] The fixing resin medium used in the present invention is an anisotropic resin.
A copolymer resin or a resin composition having an on-polar group.
You. Carboxylic acid, sulfone
Any polar group such as an acid and a phosphonic acid may be mentioned.
Bonic acid types are particularly preferred. Anionic polar group
Is a monomer having an anionic polar group
By random copolymerization, block copolymerization, or grafting
It is incorporated into a resin by copolymerization or the like. Comonomeric
Suitable examples of the body are as follows. Examples of the carboxylic acid type include ethylene-based
Unsaturated carboxylic acids, such as acrylic acid, methacrylic acid,
Crotonic acid, maleic acid, maleic anhydride, fumaral
Acid, maleic acid or fumaric acid
Esters. As the sulfonic acid type, styrene
Sulfonic acid, 2-acrylamido-2-methylpropane
Sulfonic acid and the like. The phosphonic acid type includes 2-acid
Dophosphoxypropyl methacrylate, 2-acid
Sulfoxyethyl methacrylate, 3-chloro-2-acy
And phosphonic propyl methacrylate.
You. These anionic polar group-containing monomer units
Is a free acid, sodium, potassium, etc.
Alkali metals, such as calcium and magnesium
It may be neutralized with an earth metal, zinc or the like. Resin or other simple substance which is the main component of the resin composition
The body is the same as the fixing and electro-static properties required for the toner.
Having an ethylenically unsaturated bond
One or a combination of two or more monomers is used. A suitable example of such a monomer is acrylic
Monomer, monovinyl aromatic monomer, vinyl ester
Monomer, vinyl ether monomer, diolefin monomer
And monoolefin monomers. As the acrylic monomer, for example, Embedded image Where R₁ Is a hydrogen atom or a lower alkyl group, R_Two Is hydrogen
Atom, hydrocarbon group up to 12 carbon atoms, hydroxyalkyl group
Is, Acrylic monomers, especially methyl acrylate, acrylic
Ethyl acrylate, butyl acrylate, 2-ethyl acrylate
Hexyl, cyclohexyl acrylate, acrylate
Nil, methyl methacrylate, hexyl methacrylate,
2-ethylhexyl acrylate, β-hydroxyact
Ethyl acrylate, propyl γ-hydroxyacrylate, δ
-Butyl hydroxyacrylate, β-hydroxymethac
Ethyl lylate and the like. As the monovinyl aromatic monomer, for example, Embedded image Where R_Three Is a hydrogen atom, lower alkyl group or halogen atom
Child and R_FourIs hydrogen atom, lower alkyl group, halogen
Atom, alkoxy group, amino group, nitro group, etc.
Is a phenylene group, Monovinyl aromatic hydrocarbons, for example, styrene, α-meth
Styrene, vinyltoluene, α-chlorostyrene,
o-, m-, p-chlorostyrene, p-ethylstyrene
And the like, or a combination of two or more. The following are other monomers, respectively.
No. Embedded image CH = CH-OOCR_Five Where R_Five Is a hydrogen atom or a lower alkyl group, Vinyl esters such as vinyl formate, vinyl acetate,
Vinyl lopionate and the like. Embedded image CH４CH—OR₆ Where R₆ Is a monovalent hydrocarbon group having up to 12 carbon atoms.
Vinyl ethers, such as vinyl methyl ether, vinyl
Ethyl ether, vinyl-n-butyl ether, vinyl
Phenyl ether, vinylcyclohexyl ether and the like. Embedded image Where R₇ , R₈ , R₉ Each is a hydrogen atom, lower alkyl
Or a halogen atom, Diolefins, especially butadiene, isoprene,
Loprene and the like. Embedded image Where R_TenAnd R₁₁Is a hydrogen atom or lower alkyl
Is the base, Monoolefins, especially ethylene, propylene, iso-
Butylene, butene-1, pentene-1, 4-methylpen
Ten-1 and the like. Having an anionic polar group used in the present invention
In the case of a free acid, the copolymer resin is represented by an acid value of 2 to 3
0, especially 5 to 15
It is desirable to have a degree. Anion of copolymer resin
When some or all of the polar polar groups are neutralized,
It should have an anionic polar group concentration corresponding to the acid value.
No. The concentration of the anionic polar group in the copolymer resin is high.
If less than the above range, the toner chargeability is unsatisfactory
On the other hand, if it is more than the above range, the toner
Sensitive and undesired. Preferred copolymer resins include anionic polar groups.
A monomer and one of the acrylic monomers of Chemical Formula 1 or
Contains two or more types as essential components, and
2) to (6) as optional components.
It is a polymer resin. In the present invention, an anionic polar group-containing copolymer is used.
The polymer resin can be used alone as described above,
A composition containing two or more kinds of on-polar group-containing copolymer resins,
Alternatively, an anionic polar group-containing copolymer resin and an anionic polar resin
Fixing resin even in the form of a composition with a copolymer resin having no functional group
Can be used as a fat medium. When the fixing resin medium is composed of a resin composition,
The concentration of the anionic polar group in the resin composition as a whole
Is preferably in the range described above for the copolymer resin.
No. [Magnetic Powder] Conventional magnetic toners
Magnetic powders, such as triiron tetroxide (Fe
_Three O_Four ), Iron sesquioxide (γ-Fe_Two O_Three ), Zinc iron oxide
(ZnFe_Two O _Four ), Yttrium iron oxide (Y_Three Fe_Five
O₁₂), Cadmium iron oxide (CdFe_TwoO_Four ),iron oxide
Gadolinium (Gd_Three Fe_Two O₁₂), Copper iron oxide (CuFe
_Two O_Four ), Lead iron oxide (PbFe₁₂O₁₉), Iron oxide nickel
(NiFe_Two O_Four ), Neodymium iron oxide (NdFeO)
_Three ), Barium iron oxide (BaFe)₁₂O₁₉), Iron oxide mug
Nesium (MgFe_Two O_Four ), Iron manganese oxide (MnF)
e_Two O_Four ), Iron oxide lanthanum (LaFeO)_Three ), Iron powder
(Fe), cobalt powder (Co), nickel powder (Ni), etc.
Can be used. The magnetic powder particularly suitable for the purpose of the present invention is fine particles
Is ferric oxide (magnetite). A suitable magnet
The site is octahedral with a particle size of 0.05 to 1.0 μm
belongs to. Preferred magnetite is regular octahedral and particle size
Is 0.05 to 1.0 μm. This magneta
The silica particles are composed of a silane coupling agent and a titanium-based coupling agent.
Surface treatment with a coating agent or the like. [Toner composition] Toner composition of the present invention
Is the above-mentioned fixing resin medium and magnetic powder as essential components.
Includes, but is also a compounding agent conventionally compounded in toner
Can be blended. For example, colorants and release agents
This is an example. Suitable examples of colorants (pigments) are as follows:
You. Black pigment Carbon black, acetylene black, lamb black
Aniline black. Yellow pigment Yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral
Ralfast Yellow, Nickel Titanium Yellow, Nay
Bruss Yellow, Naphthol Yellow S, Hanzayello
-G, Hansa Yellow 10G, Benzidine Yellow G,
Benzidine Yellow GR, Quinoline Yellow Lake, PA
-Mannent Yellow NCG, Tartrazine Lake. Orange pigment Red mouth yellow lead, molybdenum orange, permanent orange
GTR, pyrazolone orange, Vulcan orange, Inn
Daslen Brilliant Orange RK, Benzidine Oren
Di G, Indus Ren Brilliant Orange GK. Red pigment Bengala, cadmium red, lead red, mercury sulfide cadmium
, Permanent red 4R, risol red, pyrazo
Ron Red, Watching Red Calcium Salt, Lake
Red D, Brilliant Carmin 6B, Eosin Le
Ki, Rhodamine lake B, Alizarin lake, Brillia
Nto Carmin 3B. Purple pigment Manganese purple, fast violet B, methyl violet
Trake. Blue pigment Navy blue, cobalt blue, alkaline blue lake, victo
Rear blue lake, phthalocyanine blue, metal-free lid
Russian nin blue, phthalocyanine blue partially chlorinated
Object, first sky blue, induslen blue B
C. Green pigment Chrome green, chromium oxide, pigment green B,
Malachite Green Lake, Fanal Yellow Green
G. White pigment Zinc white, titanium oxide, antimony white, zinc sulfide. Extender pigment Barite powder, barium carbonate, clay, silica, white
Carbon, talc, alumina white. The pigment is 100 parts by weight of a fixing resin medium.
2 to 20 parts by weight, especially 5 to 15 parts by weight
use. Various waxes are used as the releasing agent for heat fixing.
And low molecular weight olefin resins. Orefi
Polypropylene resin, polyethylene,
A propylene-ethylene copolymer is used.
Pyrene is particularly preferred. [Production Method of Toner] The toner of the present invention is pulverized.
Classification method, melt granulation method, spray granulation method, polymerization method, etc.
Although it can be produced by a method known per se, a pulverization classification method is generally used.
is there. Each of these toner components can be
After pre-mixing with a mixer, the kneading device such as a twin screw extruder
Kneading using, after cooling the kneaded composition, pulverized,
Classify the toner. Generally, the particle size of toner
The median diameter of the counter is 5 to 15 μm.
It is better to be within the range of 7 to 12 μm. A magnetic powder is externally added to the toner particles. External attachment
As the magnetic powder for use, the above-mentioned magnetic powder, particularly the finely divided
Iron fossil (magnetite) is used. Magnetic powder with toner particles
To externally add the toner particles and the magnetic powder in a mixer,
What is necessary is just to throw in and dry-mix sufficiently. The magnetic powder alone can be added externally.
Generally combined with flow improvers such as hydrophobic fumed silica
The fluidity improver is preferably added to the toner resin medium.
Used in an amount of 0.05 to 5 parts by weight per 100 parts by weight of material
Is good. External addition of fluidity improver and magnetic powder to toner
Before grinding, the fluidity improver and the magnetic powder should be ground beforehand.
Mix well below and add this mixture to the toner
It is good to crush. [Use] The toner according to the present invention is a magnetic toner.
Mix with the rear to use as a two-component developer. Magnetic key
Preferably, the carrier is a ferrite-based magnetic carrier.
, Especially the group consisting of Cu, Zn, Mg, Mn and Ni
At least one, preferably two, of the metal components selected from
Soft ferrite containing above, for example, copper-zinc-ma
Sintered ferrite particles of gnesium ferrite, especially spherical
Particles are used. The surface of the magnetic carrier is uncoated
May be used, but in general, silicone resin, fluorine
Resin, epoxy resin, amino resin, urethane resin, etc.
It is good to be coated with. The saturation magnetization of the carrier is
30 to 70 emu / g, especially in the range of 40 to 60 emu / g
It is desirable to have. The particle size of the magnetic carrier is 20 to 1
40 μm, especially in the range of 50 to 100 μm.
Good. The mixing ratio between the magnetic carrier and the toner is
Generally a weight ratio of 98: 2 to 90:10, especially 97: 3
It is preferred that the weight ratio be from 94: 6. In the electrostatographic copying method using the toner of the present invention,
The formation of the electrostatic latent image is performed by any method known per se.
Can be performed, for example, uniform photoconductive layer on conductive substrate
And then image exposure to form an electrostatic latent image
Can be. The development of an electrostatic image is based on the magnetic properties of a two-component magnetic developer.
This is easily done by bringing the brush into contact with the substrate.
The toner image formed by development is transferred onto copy paper,
This toner image is fixed by contacting it with a heating roll.
Is performed. [0060] The present invention is further described by the following examples. Example 1 (Toner composition) (parts by weight) Fixing resin 100 Styrene acrylic copolymer having carboxyl group Colorant carbon black 8.5 Magnetic powder magnetite 2.0 The above composition is melt-kneaded with a twin-screw extruder.
Crushed with a jet mill, classified with an air classifier,
Thus, toner particles having an average particle size of 10.0 μm were obtained. This toner
The particles have a mean particle size of 0.2 μm as spacer particles.
Magnetite was added in an amount of 0.8 to 100 parts by weight of toner
Parts by weight and a 0.015 μm hydrophobic
0.4 parts by weight of fine particles per 100 parts by weight of toner particles
Parts and mix for 2 minutes with a Henschel mixer.
Thus, the toner of the present invention was obtained. Embodiment 2 The internal addition amount of magnetite was 5.0 parts by weight, and
The external addition amount of magnetite as sir particles is 0.5 parts by weight.
A toner of the present invention was obtained in the same manner as in Example 1 except that
Was. Embodiment 3 Except that the internal addition amount of magnetite was 0.5 parts by weight
In the same manner as in Example 1, a toner of the present invention was obtained. Comparative Example 1 In Example 1, carboxy resin was used as a fixing resin in the resin.
After using a styrene acrylic copolymer without a sil group,
Except for this, a toner was produced in the same manner as in Example 1. Comparative Example 2 Conducted except that the internal addition amount of magnetite was 0.2 parts by weight
A toner was produced in the same manner as in Example 1. Comparative Example 3 The magnetite content was 8.0 parts by weight,
The external addition amount of magnetite is 1.2 parts by weight
A toner was produced in the same manner as in Example 1 except for the above. Comparative Example 4 Conducted except that the internal addition amount of magnetite was 0.1 parts by weight
A toner was produced in the same manner as in Example 1. Comparative Example 5 Azo dyes (trade name “S-34”
Ent. Chemical Co., Ltd.)
A toner was obtained. Comparative Example 6 A salicylic acid derivative (trade name “E-8”)
4 "manufactured by Orient Chemical Co.)
Thus, a toner was obtained. [Evaluation of Toner] (1) Measurement of absorbance 100mg of toner is precisely weighed and put into a sample bottle.
Add 50 ml of methanol and stir for 10 minutes with a ball mill
And leave for 15 hours. Take 20 ml of the supernatant
Measure the absorbance of the sample after centrifugation.
You. Absorbance measurement was performed using a spectrophotometer "U-3"
210 "manufactured by Hitachi, Ltd. was used. Table 1 shows the evaluation results.
Show. (2) Evaluation test Each toner obtained in each of the examples and comparative examples has an average particle size.
100μm diameter ferrite carrier is blended and mixed
Thus, a two-component developer having a toner concentration of 3.5% was prepared.
Then, an electronic copying machine manufactured by Mita Kogyo Co., Ltd. (trade name "DC-7
085 "), 100,000 copies were made.
The original used for copying is a text original and the area ratio of the black part is 8%.
Originals sampled at predetermined intervals
A black portion having an area ratio of 15% was used. Each test method is as follows. (A) Image density (ID) For every predetermined number of copies, up to 100,000 copies
Use a reflection densitometer (Model “TC-6D” manufactured by Tokyo Denshoku Co., Ltd.)
It measured using. (B) Fog density (FD) The density of the non-image area is measured using a reflection densitometer (Model “TC-6D” Tokyo
Measured with Denshoku Co., Ltd.) and base paper (paper density before copying)
And the difference. Table 1 shows the evaluation results. (C) Resolution Make a copy using the specified chart document, and copy the copied image
When the peak value in the Rodensitometer is 0.8 or more,
The base value is 0.4 or more, and the difference between the peak value and the base value is
The number with the difference of 0.6 or more was counted. Table 1 shows the evaluation results.
Show. (D) Transfer efficiency The amount of toner in the toner hopper before copying starts
Measure the amount in the toner hopper after copying and calculate the difference.
The toner consumption was calculated. On the other hand, during the predetermined number of copies,
Measure the amount of toner collected in the cleaning process,
The amount of collected toner was obtained. From these values, the toner
Was calculated after copying 100,000 sheets. Evaluation results
Are shown in Table 1. (E) Toner scattering Visual observation of toner scattering in the copier at the end of 100,000 sheet copying
It was observed and evaluated according to the following criteria. Table 2 shows the evaluation results.
You. ○: No toner scattering ×: toner scattering (F) Spent amount 400 mesh of developer sampled every predetermined number
And place it on the screen of
And the carrier. Carriers left on the screen
5 g is put into a beaker, and toluene is further added thereto,
Spent to dissolve toner adhered to carrier surface
You. Then pull the carrier with a magnet from under the beaker
Drain the toluene solution with the solution. This is without toluene
Repeat several times until color is obtained, then remove toluene in oven
Dry and weigh. Weight in beaker and dry
The difference in weight after drying is the spent amount. The spent amount is
Expressed in mg of spent toner adhering per gram of rear
did. Table 1 shows the evaluation results. (G) Toner charge amount 200mg of developer is used for "Blow-off powder charge measuring device"
(Manufactured by Toshiba Chemical Co., Ltd.) and measure
It was expressed in terms of the charge amount per gram. Table 1 shows the evaluation results.
You. [0073] [Table 1][0074] According to the present invention, a two-component magnetic developer
In toner, an anionic polar resin is used as a fixing resin medium.
Using a copolymer resin having a functional group or a resin composition, and
The wavelength of the extract obtained by extracting the toner with methanol is from
The absorption peaks at 700 nm and 280 to 350 nm
Absorbance is virtually zero, which is necessary
The minimum triboelectric charge controllability is obtained,
Transfer of control agent to carrier surface and this spent
Electrification failure is eliminated and the charging performance of the toner is
Can stabilize the life of toner and carrier
Can be extended. The resin medium 1 is provided on the surface and inside of the toner.
When magnetic powder is contained within 8 parts by weight per 00 parts by weight
In both cases, the internal addition amount and the external addition amount are selected within a certain range.
Effectively prevents toner scattering and fog,
More completely prevents the development of images, increases development sensitivity,
It is possible to improve the rate and achieve high durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a wavelength 4 of an extract obtained by extracting a toner containing a chromium complex dye (2: 1) as a charge control agent with methanol.
It is an absorbance curve in the range of 00 to 700 nm. FIG. 2 shows a wavelength of 280 to 350 nm of a methanol extract of a toner using a salicylic acid metal complex as a charge control agent.
FIG. FIG. 3 Using the toner used for the measurement in FIG. 1 as a two-component magnetic developer, a carrier in which poor charging due to spent is generated is similarly extracted with methanol, and the absorbance of the extracted solution at a wavelength of 400 to 700 nm. It is the graph which measured the curve. FIG. 4 is a graph plotting the relationship between mixing time and spent amount when a mixture of a toner containing a charge control agent and a magnetic carrier and a mixture of a toner containing no charge control agent and a magnetic carrier are mixed. is there. FIG. 5 is a graph plotting the relationship between the mixing time and the charge amount when a mixture of a toner containing a charge control agent and a magnetic carrier and a mixture of a toner containing no charge control agent and a magnetic carrier are mixed. It is. FIG. 6 is a graph showing a relationship between a spent amount of a carrier to which spent is attached and a charge control agent in spent toner. FIG. 7 is a graph showing a relationship between a mixing time and a spent amount in a case where each component alone in a toner is mixed with a magnetic carrier. FIG. 8 is an explanatory diagram illustrating the occurrence of charging failure due to the occurrence of spent in a conventional two-component magnetic developer. FIG. 9 is an absorbance curve of an extract obtained by extracting the toner of the present invention with methanol.

Continuation of the front page (72) Inventor Kazuhiko Fujii 1-2-28 Tamazo, Chuo-ku, Osaka-shi Mita Kogyo Co., Ltd. (72) Inventor Kazuya Nagao 1-2-28 Tamatsuzo, Chuo-ku, Osaka Mita Kogyo (56) References JP-A-3-257462 (JP, A) JP-A-4-313759 (JP, A) JP-A-4-359260 (JP, A) JP-A-4-9866 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 9/08 G03G 9/10

Claims (1)

(57) [Claim 1] In a two-component magnetic developer toner,
The fixing resin medium is a copolymer resin or a resin composition having an anionic polar group, and the toner contains a magnetic powder within 8 parts by weight per 100 parts by weight of the resin medium on the surface and inside of the toner. Of these, 0.3 to 1.5 parts by weight of the liquid sprayed on the surface of the toner and at least 0.3 part by weight of the liquid added to the inside of the toner, and the extracted liquid obtained by extracting the toner with methanol. A two-component magnetic developer toner, wherein the absorbance at the absorption peaks at wavelengths of 400 to 700 nm and 280 to 350 nm is substantially zero.