JP3364596B2 - Electrophotographic toner and process cartridge recycling method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner, in particular, an electrophotographic toner having a high image density and resolution, a low fog generation and a high transfer efficiency and a stable process cartridge regenerating method.

[0002]

2. Description of the Related Art In recent years, the trend of reusing resources in order to protect the natural environment and reduce costs is becoming common, and it is used in image forming apparatuses such as copying machines and printers that form images by electrophotography. Process cartridges are naturally being reused and are becoming popular. Image forming apparatuses such as copiers and printers, which are becoming digital and high-speed, are not limited to newly sold products, and even when recycled products or recycled parts are used, they are currently operating under severe operating environments of high temperature and high humidity. It is required to endure continuous operation for a long time and always display a stable and high-quality clear image.

For example, Japanese Laid-Open Patent Publication No. 7-121086 includes a first frame having a developing carrier and a second frame having a developing means and a developer accommodating means for accommodating the developer used in the developing means. The process cartridge is disassembled into the first frame and the second frame, and the developer is replenished into the developer accommodating section through the opening provided in the developer accommodating section, and then a seal is detachably attached to the opening of the developer accommodating section. This shows a method of remanufacturing a process cartridge in which the opening is closed to close the opening and then the first frame and the second frame are locked to reassemble the process cartridge. In this remanufacturing method, when the process cartridge is remanufactured, the first frame having the developing carrier, the developing means, and the second frame having the developer accommodating means for accommodating the developer used for the developing means are provided. Since the developer can be disassembled to replenish the developer and the seal can be attached, it is possible to prevent the development carrier from being damaged.

Japanese Patent Laid-Open No. 8-305258 discloses that
A step of separating a first frame body holding a developing member attached to the opening of the developer accommodating portion and a second frame body holding an electrophotographic photosensitive member, and developing from the separated first frame body The step of removing the member, the step of filling the developer from the opening of the first frame body from which the developing member is removed, the step of mounting the developing member in the opening after filling the developer, and the step of mounting the developing member. 7 shows a process cartridge remanufacturing method including a step of connecting a first frame body and a second frame body. In this process cartridge recycling method, since the used process cartridge is used as it is, the cartridge can be easily recycled due to the improved recycling efficiency.

[0005]

However, even if the consumable parts are replaced at the time of reproduction, the parts that have been used once and are exhausted are reused. Therefore, the performance of the image forming apparatus is insufficient if ordinary toner is used. is there. Therefore, according to the present invention, when the process cartridge to be reproduced is filled, the image density and the resolution are high, the fog is small, and the transfer efficiency is high.
It is an object of the present invention to provide an electrophotographic toner and a process cartridge recycling method that have a high charge amount and are stable.

[0006]

The electrophotographic toner according to the present invention comprises a salt of an organic compound having a metal ion represented by the general formula (I) and a carboxy ion, and a metal complex ion and a carboxy ion represented by the general formula (II). Average particle size 1.0 in which a charge control agent containing a salt of an organic compound having
It contains ferrite particles with a particle size of less than μm. n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [ _CM ] ^{n +} (II) (M is a metal, _CM is a metal complex, R is an aryl group, and n is 1).
Since the charge control agent-containing ferrite particles in which the charge control agent is uniformly dispersed are used, performances such as image density, resolution, fog and transfer efficiency of the electrophotographic toner can be improved. .

In the embodiment of the present invention, the metal serving as the metal ion and the metal complex ion is iron, chromium, nickel,
It is selected from one or more of cobalt, tin, manganese, cerium, silver, zinc, magnesium, zirconium, beryllium, copper, aluminum, barium, calcium, titanium, indium, lithium and cadmium. The metal complex ion is selected from one or more of basic chromium hydroxide ion, basic chromium chloride ion, basic zinc chloride ion and basic chromium sulfate ion. The organic compound having a carboxy ion is selected from one or more of salicylic acid, salicylic acid derivatives, naphthoic acid and naphthoic acid derivatives.

In the process cartridge recycling method according to the present invention, the process cartridge mounted on the electronic copying machine is removed to form the process cartridge.
A step of separating the (14) and the second frame (15), and the developing roller (1), the seal member (2), the developer accommodating portion (3) and the separated first frame (14). The developing blade (6) is removed, the photosensitive drum (7), the charging roller (8), and the cleaning blade (9) are removed from the separated second frame body (15), and the seal member (2) and the photosensitive drum are removed. (7) and cleaning blade (9)
While discarding the developing roller (1), developer storage (3),
A step of cleaning the developing blade (6), the charging roller (8) and the second frame body (15), and attaching a new seal member (2) having a hot melt film to the first frame body (14),
The developing roller (1) and the developing blade (6) filled with the electrophotographic toner in the developer accommodating portion (3) and cleaned are the first frame body.
Attached to (14), new photoconductor drum (7), cleaned charging roller (8) and new cleaning blade
Step of attaching (9) to the second frame (15) and developing roller
(1), a seal member (2), a developer accommodating portion (3), a first frame (14) to which a developing blade (6) is attached, and a photosensitive drum
(7), connecting the charging roller (8) and the second frame (15) to which the cleaning blade (9) is attached. When the first frame body (14) and the second frame body (15) connected to each other are attached to the electronic copying machine and the electronic copying machine is operated, the image density is 1.
40 or more, resolution 4.0 or more, fog 0.05 or less,
The transfer efficiency is 85.00% or more.

In the embodiment of the present invention, the first frame body (14)
It may include a step of setting a process cartridge in which the second frame body (15) and the second frame body (15) are combined in a laser beam printer and performing a copy test.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an electrophotographic toner and a process cartridge recycling method according to the present invention will be described below with reference to FIGS.

When reproducing the process cartridge, first, the process cartridge shown in FIG. 1 mounted in the electronic copying machine is removed, and as shown in FIG. 2, the first frame body (14) constituting the process cartridge. And the second frame (15) are separated. Next, as shown in FIG. 3, from the separated first frame body (14) to the developing roller (1), the ring (1a), and the seal member.
(2), the developer accommodating portion (3) having the seal portion (3a) and the developing blade (6) are removed, and as shown in FIG. 4, the drum gear (7a) is separated from the separated second frame body (15). , Protruding gear (7b)
And the photoconductor drum (7) having the contact member (7c), the charging roller (8), the contact cap (8a), the cleaning blade (9) and the squishy sheet (10) are removed, and the hopper cap is removed from the developer storage section (3). Remove (3c). After that, the sealing member (2) to which the hot melt film or the adhesive is attached, the photosensitive drum (7) and the cleaning blade (9) are discarded, and the developing roller (1), the developer accommodating portion (3), and the hopper cap are also disposed. (3c), developing blade (6), charging roller (8), contact cap (8a), squeeze sheet (10) and second frame (15), especially waste developer reservoir (11) is cleaned to remove toner. Remove. To clean each part, blow air to each part to remove the residue attached to each part, and then wipe the surface of each part with a cloth containing a detergent such as a surfactant or alcohol. Completely remove the residue and dry.

Next, the contact member (1c) of the developing roller (1),
Attach the fixing plate (1d), gear (1e), gear cover (1f), developer (toner) leak prevention seal (5), and antenna wire (4) to the first frame (1
Remove from 4) and clean these parts as above. After that, a new seal member (2) having a hot melt film is attached to the first frame body (14) with a seal-dedicated attaching device, and the antenna wire (4) is attached to the first frame body (14), and a new electronic device is attached. Fill the developer storage (3) with photographic toner, attach the hopper cap (3c), and clean the developing roller (1), ring (1a), developer leak prevention seal (5),
Fixed plate (1d) of developing roller (1), gear (1d) of developing roller (1)
e), gear cover (1f), contact member (1c) and developing blade
(6) is attached to the first frame body (14), and the first frame body (14) is reproduced. At the same time, put a scrap sheet (1
0), a new photoconductor drum (7), a new cleaning blade (9), the cleaned charging roller (8) and contact cap (8a) are attached to the second frame (15), and the second frame Body (1
5) Play.

In the present embodiment, the electrophotographic toner is
A specific toner containing a ferrite particle powder in which a charge control agent is uniformly dispersed is used. This charge control agent contains a salt of an organic compound having a metal ion and a carboxy ion represented by the general formula (I) and a salt of an organic compound having a metal complex ion and a carboxy ion represented by the general formula (II). n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [ _CM ] ^{n +} (II) (M is a metal, _CM is a metal complex, R is an aryl group, and n is 1).
Metals consisting of metal ions and metal complex ions are iron (Fe), chromium (Cr), nickel (N
i), cobalt (Co), tin (Sn), manganese (Mn), cerium (Ce), silver (Ag), zinc (Zn), magnesium
(Mg), zirconium (Zr), beryllium (Be), copper
(Cu), aluminum (Al), barium (Ba), calcium (Ca), titanium (Ti), indium (In), lithium (Li) and cadmium (Cd) are selected from one kind or two or more kinds. The metal complex ion is a basic metal complex ion selected from one or more of basic chromium hydroxide ion, basic chromium chloride ion, basic zinc chloride ion and basic chromium sulfate ion. The organic compound having a carboxy ion is one or two of salicylic acid, a salicylic acid derivative, naphthoic acid and a naphthoic acid derivative.
It is selected from more than one species.

As shown in FIG. 5, in the ferrite particles containing the charge control agent, the ferrite (16) and the charge control agent (17) are uniformly mixed, and the ferrite (16) and the charge control agent (17) are mixed. The ferrite particles (18) containing a charge control agent and having an average particle diameter of 1.0 μm or less are integrally attached. Since the ferrite particles (18) containing the charge control agent, in which the ferrite (16) and the charge control agent (17) are uniformly mixed and the ferrite (16) and the charge control agent (17) are integrally attached, are used. Charge control agent (1
7) is uniformly dispersed, the charge control agents (17) do not aggregate with each other, and the toner does not have uneven charging. As a result, the toner is always charged with a stable charge amount. Since the ferrite particles that function as a magnetic material are also uniformly dispersed in the toner, other toner particles such as a binder resin are evenly attached to the ferrite particles, and the toner particles are well conveyed to the magnetic roll together with the ferrite particles, At the time of development, a sufficient amount of toner can be supplied to the photoconductor to prevent a decrease in image density. It is also possible to prevent toner particles from scattering from the sleeve due to a decrease in magnetic force. Therefore, the toner using the ferrite particles uniformly containing the charge control agent can prevent the image density and the resolution from decreasing and the fog from occurring, and improve the transfer efficiency. When the average particle size of the ferrite particles exceeds 1.0 μm, the dispersibility in the toner is poor and the charge amount of the toner becomes non-uniform, so that the image density during transfer is lowered.

Since the charge control agent contains a mixture of metal ions and metal complex ions, it has good compatibility with the binder resin and has the effect of stabilizing the potential on the toner surface. Further, since it is excellent in charging stability with respect to a carrier for two-component developer, and is excellent in frictional electrification and stability between toner particles and between a one-component toner and a toner carrier such as a sleeve,
The image density after transfer is high, and background stains and fixing defects do not occur.

The metal to be a metal ion and the metal to be a metal complex ion are iron, chromium, nickel, cobalt, tin,
It is selected from the group consisting of manganese, cerium, silver, zinc, magnesium, zirconium, beryllium, copper, aluminum, barium, calcium, titanium, indium, lithium and cadmium.

Subsequently, the developing roller (1), the seal member (2),
The first frame (14) with the developing blade (6) and the developer storage (3) attached, and the second frame with the photosensitive drum (7), the charging roller (8) and the cleaning blade (9) attached. After forming a unitized process cartridge by connecting it to the frame body (15), the process cartridge is set in a laser beam printer and a copy test is conducted. At that time, the image density is 1.40 or more and the resolution is 4.40. 0 or more, fog is 0.05 or less, and transfer efficiency is 85.00% or more.

Since the charge control agent-containing ferrite particles in which the charge control agent is uniformly dispersed are used, performances such as image density, resolution, fog and transfer efficiency of the electrophotographic toner can be improved.

In producing the ferrite particles containing the charge control agent, first, a carboxy compound, water and a hydroxide of an alkali metal are mixed to obtain an ion-containing aqueous solution of the carboxy compound, and a metal salt and water. An alkali metal hydroxide is mixed to obtain a metal salt-containing aqueous solution. Next, after the obtained ion-containing aqueous solution and the metal salt-containing aqueous solution are mixed and neutralized to obtain a charge control agent, a charge control agent and an iron-containing salt,
Water and an alkali metal hydroxide are mixed and oxidized to obtain a mixed liquid of ferrite and a charge control agent, and the obtained mixed liquid is filtered, washed, dried and pulverized.

To prepare ferrite particles containing a charge control agent by another method, first, a carboxy compound, water and
An alkali metal hydroxide is mixed to obtain an ion-containing aqueous solution of a carboxy compound, and an iron-containing metal salt, water, and an alkali metal hydroxide are mixed to obtain an iron-containing metal salt-containing aqueous solution. Next, after the obtained ion-containing aqueous solution and the metal salt-containing aqueous solution are mixed and neutralized to obtain a charge control agent, the aqueous solution containing the charge control agent is oxidized by aeration to oxidize the ferrite and the charge control agent. A mixture is obtained and the mixture obtained is filtered, washed, dried and ground.

In the above-mentioned manufacturing method, the binder resin, the colorant, the charge control agent, the wax and the like are not put into the mixer at one time and reacted, and the raw material of the ferrite particles and the charge control agent are first put in an alkaline aqueous solution. By oxidizing, filtering, washing, drying and pulverizing, ferrite particles uniformly containing the charge control agent can be obtained. When the obtained ferrite particles containing a charge control agent are kneaded with a binder resin, a wax and the like, a high-performance toner can be produced which prevents a decrease in image density and resolution and prevents fogging, and enhances transfer efficiency.

[0022]

Examples [Production of ferrite particle powder for electrophotographic toner] When preparing electrophotographic toner, chromium sulfate 1
Chromium sulfate was dissolved in water by adding 10 parts to 1690 parts of water. Further, 10 parts of sodium hydroxide was added to 1690 parts of water to dissolve the sodium hydroxide in water. A sodium hydroxide aqueous solution was added to the chromium sulfate aqueous solution, and the mixed aqueous solution was maintained at a temperature of 90 ° C. while stirring. 70 parts of 3,5-ditertiarybutylsalicylic acid was added to an aqueous solution prepared by dissolving 10 parts of sodium hydroxide in 1330 parts of water and stirred, and the obtained solution was added to the mixed aqueous solution and reacted at 90 ° C. for 1 hour. It was

Next, 3000 parts of ferrous sulfate was added to 4400 water.
1000 parts of sodium hydroxide was added to 1500 parts of water and dissolved, and the resulting solution was added to the mixed aqueous solution and stirred. Next, while blowing air into the mixed aqueous solution, an oxidation reaction is performed at 90 ° C. for 5 hours. After completion of the reaction, the mixture was filtered and washed with water and then dried at 120 ° C. for 6 hours
After pulverization, 0.8% of a charge control agent, which is a mixture of chromium 3,5-ditertiarybutylsalicylate having an average particle diameter of 0.5 μm and a salt of 3,5-ditertiarybutylsalicylic acid and a basic chromium sulfate complex, is crushed. Ferrite uniformly contained (Fe
840 parts of O.Fe ₂ O ₃ ) particle powder was obtained. in this way,
A ferrite particle powder for a toner for electrophotography containing a charge control agent uniformly was obtained.

[Production of toner for electrophotography and performance confirmation]
A toner was manufactured in the following blending ratio. Styrene-acrylic acid ester copolymer 49 parts Low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Co., Ltd.) 3 parts Ferrite particle powder for toner for electrophotography containing charge control agent 48 parts Drying with a mixer (Henschel mixer) After mixing, they were kneaded with a twin-screw kneader set at a temperature of 130 ° C. The obtained kneaded product was cooled, coarsely pulverized to about 2 mm or less with a hammer mill, and then finely pulverized with a jet pulverizer having a coarse powder classification function. The obtained fine powder was classified by an airflow classifier to obtain a raw toner having an average particle size of 9 μm. To 100 parts of the obtained raw toner, 0.3 part of hydrophobic colloidal silica and 1.0 part of calcium titanate are added and mixed (Henschel mixer).
After mixing with, the aggregate was removed with a vibrating screen to obtain a toner. Next, a regenerated process cartridge is filled with this toner, and a commercially available Canon copying machine model “LBP-
The continuous copying test of 6000 sheets was performed by "A304GII". As shown in Table 1, the transfer efficiency was high with no deterioration in image density and resolution and generation of fog.

[Toner Production / Performance Confirmation Comparison] Toners were produced in the following mixing ratios. Styrene - parts of acrylic acid ester copolymer 49 low molecular weight polypropylene NP-505 (manufactured by Mitsui Petrochemical Industries, Ltd.) 3 parts Ferrite (FeO · Fe ₂ O ₃₎ particles 44 parts Charge controlling agent (3,5-ditertiary butyl salicylate Chromium) 4 parts After dry-mixing the above materials with a mixer (Henschel mixer), they were kneaded with a twin-screw kneader whose temperature was set to 130 ° C. The obtained kneaded product was cooled, coarsely pulverized to about 2 mm or less with a hammer mill, and then finely pulverized with a jet pulverizer having a coarse powder classification function. The obtained fine powder was classified by an airflow classifier to obtain a raw toner having an average particle size of 9.1 μm. To 100 parts of the obtained raw toner, 0.3 parts of hydrophobic colloidal silica and 1.0 part of calcium titanate were added and mixed with a mixer (Henschel mixer), and then aggregates were removed by a vibrating screen to obtain a toner.

Next, a regenerated process cartridge was filled with this toner, and a continuous copying test of 6000 sheets was carried out by a commercially available Canon copying machine model "LBP-A304GII". Table 1 shows the results of evaluating the copied image at the start of the continuous copying test and the copied image at the end of the continuous copying test for each item for each of the examples and comparative examples. The Electrophotographic Society Test Chart No. 1-R was used as a copy sample. As the image density, the density of the black solid portion of the copied image was measured with a Macbeth densitometer. The resolution was evaluated by visually observing the copied image with a magnifying glass and counting the number of individual thin lines. For fog, the density of the non-image portion of the copied image was measured with a Macbeth densitometer. The transfer efficiency is a value obtained by dividing the waste toner amount (increase in the waste toner portion) by the amount of used toner (increase in the developing portion), and multiplying this by 100 to subtract 100. As shown in Table 1, the image density and resolution were low, fog was often generated, and the transfer efficiency was low.

[0027]

[Table 1]

[0028]

As described above, according to the present invention, the electrophotographic toner according to the present invention is used in the regenerated process cartridge to prevent the image density and resolution of the electrophotographic toner from being lowered and the fog to be prevented from being transferred. The efficiency can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view of a process cartridge.

FIG. 2 is a perspective view showing a state in which a first frame body and a second frame body of the process cartridge are opened.

FIG. 3 is an exploded perspective view showing a first frame of the process cartridge.

FIG. 4 is an exploded perspective view showing a second frame of the process cartridge.

FIG. 5 is an enlarged view of ferrite particles containing a charge control agent.

[Explanation of symbols]

(1) ・ ・ Developing roller, (1a) ・ ・ Ring, (1c) ・ ・ Contact member, (1d) ・ ・ Fixing plate, (1e) ・ ・ Gear, (1f) ・
・ Gear cover, (2) ・ ・ Seal member, (2a) ・ ・ Tab, (3) ・ ・ Developer container, (3a) ・ ・ Seal member,
(3b) ・ ・ Opening part, (3c) ・ ・ Hopper cap, (4)
..Antenna wire, (5) .. developer (toner) leakage prevention seal, (6) .. Developing blade, (7) .. photosensitive drum, (7a) .. drum gear, (7b) .. projection gear , (7
c) ・ ・ Contact member, (8) ・ ・ Charging roller, (8a) ・ ・ Contact cap, (9) ・ ・ Cleaning blade, (10)
..Squi sheet, (11) .. Waste developer (toner) reservoir, (14) .. First frame, (15) ,. Second frame, (1)
6) ・ ・ Ferrite, (17) ・ ・ Charge control agent, (18) ・ ・
Ferrite particles containing charge control agent,

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-295298 (JP, A) JP-A-8-6298 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/097

Claims (6)

(57) [Claims] 1. A charge control agent containing a salt of an organic compound having a metal ion and a carboxy ion represented by the general formula (I) and a salt of an organic compound having a metal complex ion and a carboxy ion represented by the general formula (II) is uniform. An electrophotographic toner comprising a ferrite particle powder having an average particle size of 1.0 μm or less dispersed in a toner. n [R-COO] ^-. [M] ^{n +} (I) n [R-COO] ^-. [ _CM ] ^{n +} (II) (M is a metal, _CM is a metal complex, R is an aryl group, and n is 1).
~ Indicates an integer of 8) 2. Metals that become metal ions and metal complex ions include iron, chromium, nickel, cobalt, tin, manganese, cerium, silver, zinc, magnesium, zirconium, beryllium, copper, aluminum, barium, calcium, titanium, The toner for electrophotography according to claim 1, which is selected from one kind or two or more kinds of indium, lithium and cadmium. 3. The metal complex ion is selected from one or more of basic chromium hydroxide ion, basic chromium chloride ion, basic zinc chloride ion and basic chromium sulfate ion. The toner for electrophotography according to item 1. 4. The electron according to claim 1, wherein the organic compound having a carboxy ion is selected from one or more of salicylic acid, salicylic acid derivatives, naphthoic acid and naphthoic acid derivatives. Photographic toner. 5. A process of removing a process cartridge mounted on an electronic copying machine to separate a first frame body and a second frame body which form the process cartridge, and developing from the separated first frame body. While removing the roller, the seal member, the developer accommodating portion, and the developing blade, the photosensitive drum, the charging roller, and the cleaning blade are removed from the separated second frame, and the seal member, the photosensitive drum, and the cleaning blade are discarded, Developing roller,
The process of cleaning the developer accommodating portion, the developing blade, the charging roller, and the second frame, and the new seal member having the hot melt film
Attached to the frame body of claim 1 and any one of claims 1 to 4.
The electrophotographic toner according to the item 1 is filled in the developer storage portion,
Attaching the cleaned developing roller and developing blade to the first frame, and attaching a new photosensitive drum, cleaned charging roller and new cleaning blade to the second frame, developing roller, seal member, and developer storage And a developing blade attached to the first frame body, and a step of connecting the second frame body to which the photosensitive drum, the charging roller, and the cleaning blade are attached, the first frame body and the second frame body being connected. The image density when the electronic copier is operated by attaching the frame body and the frame body to the electronic copier is 1.40.
As described above, the process cartridge reproducing method is characterized in that the resolution is 4.0 or more, the fog is 0.05 or less, and the transfer efficiency is 85.00% or more. 6. The process cartridge recycling method according to claim 5, further comprising the step of setting a process cartridge having the first frame body and the second frame body coupled to each other in a laser beam printer and performing a copy test.