JP3993273B2 - Cleaning method for toner production apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for cleaning a toner manufacturing apparatus used in electrophotography, electrostatic recording, and the like.
[0002]
[Prior art]
Conventionally, a method for producing a toner for developing an electrostatic charge image is obtained by mixing and kneading raw materials such as a resin and a colorant, passing through a cooling step, finely pulverizing with a jet mill or the like, and adding additives as necessary. Then, after sieving, the container is filled into a product.
Here, since the toner raw material prescription varies depending on the copying machine to be used, it is often necessary to clean the apparatus in order to produce a plurality of types on the same production line. In particular, complete cleaning is required for cleaning between different types of toner with different chargeability and mono-color and full-color toner colors. Normally, after disassembling the device, the deposits on the device wall are removed by air blow or a vacuum cleaner. A general method is to remove deposits by suction, washing with water or an organic solvent, or a combination thereof.
[0003]
[Problems to be solved by the invention]
However, it is difficult to completely remove deposits by air blow or suction, and cleaning can be performed only at a simple level. Washing with a solution is effective for complete washing, but in the case of washing with water, much labor is required, such as drying after washing and wastewater treatment being necessary.
Cleaning with an organic solvent also has a safety problem because of its high ignitability, and there are many unfavorable points for the health of users. In addition, the operator itself is a complicated manual operation, requiring time and manpower for cleaning, and the cleaning cost and the loss due to the stoppage of the line operation are great.
[0004]
[Means for Solving the Problems]
Accordingly, an object of the present invention is to clean a toner manufacturing apparatus characterized in that a sublimable solid pellet collides with a wall surface of a toner manufacturing apparatus at high speed to remove deposits made of styrene resin on the wall surface. This is achieved by adopting the method.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The cleaning method of the toner manufacturing apparatus of the present invention can be employed in a normal toner manufacturing process. As a normal production method, first, toner raw materials are mixed, kneaded with a melt extruder, etc., extruded into a plate shape, cooled and solidified, pulverized and classified, and additives are added to obtain a toner material.
As the toner raw material, a resin and a colorant are used as essential components. For example, a charge control agent and other toner property imparting agents can be used as necessary.
[0006]
As the binder resin, for example, various known resins suitable for toner can be used. For example, styrene resin, vinyl chloride resin, rosin modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate resin, xylene Resin, polyvinyl butyral resin, polycarbonate resin, etc. are mentioned. Two or more of these resins can be used in combination. In particular, it is preferable to use a styrene resin, a saturated or unsaturated polyester resin, and an epoxy resin as the main resin.
As the colorant for toner, various known colorants can be used. For example, carbon black, nigrosine, benzidine yellow, quinacridone, rhodamine B, phthalocyanine blue and the like are preferably used. The colorant is generally used in a proportion of 0.1 to 30 parts by weight, preferably 3 to 15 parts by weight per 100 parts by weight of the resin.
[0007]
As the charge control agent, various known charge control agents can be used. Examples include positive charge control agents such as quaternary ammonium salts, nigrosine dyes, triphenylmethane dyes, styrene-aminoacrylate copolymers, polyamine resins, and negative charge control agents such as monoazo metal complex salts and metal alkylsalicylate compounds. It is done. The charge control agent is usually used at a ratio of 0.1 to 10 parts by weight per 100 parts by weight of the resin.
[0008]
As various toner property imparting agents, for example, polyalkylene waxes such as polyethylene wax and polypropylene wax can be used to prevent offset. In addition, inorganic fine particles such as titania, alumina, and silica can be used to improve fluidity and aggregation resistance. These toner property-imparting agents are usually used at a ratio of 0.1 to 10 parts by weight per 100 parts by weight of the resin.
Further, when the toner is a magnetic toner, it can contain magnetic particles such as ferrite and magnetite, and alloys or compounds containing ferromagnetic elements such as iron, cobalt and nickel. The magnetic particles are usually used at a ratio of 20 to 70 parts by weight per 100 parts by weight of the binder resin.
[0009]
Next, the cooled and solidified pellet-like toner is coarsely pulverized by a coarse pulverizer such as a hammer type pulverizer so that the weight average particle size is about 100 to 3000 μm, preferably about 300 μm. Here, the weight average particle size is a median value particle size of particle size-weight distribution, and can be measured by, for example, a Coulter Counter manufactured by Coulter Electronics.
[0010]
The mixing device has a rotating part such as a blade or a screw in the machine, such as a Henschel mixer manufactured by Mitsui Mining Co., Ltd., a Ladige mixer manufactured by Matsubo, a Nauta mixer manufactured by Hosokawa Micron, a super mixer manufactured by Kawata, or the container itself. Can be used for general V-type mixers that rotate.
As the kneading apparatus, continuous extruders such as a ZSK type extruder manufactured by W & P, a Kneader manufactured by BUSS, a TEM type extruder manufactured by Toshiba Machine Co., Ltd., a PCM type extruder manufactured by Ikekai Co., Ltd., and a Nedex manufactured by Mitsui Mining Co., Ltd. It can also be used for batch type kneaders.
[0011]
As a cooling device, it can be used for a drum cooler manufactured by Mitsui Mining Co., Ltd., Mitsubishi Chemical Engineering, or a belt cooler manufactured by NBC.
As pulverizers, NPK type I / IDS jet mill, Hosokawa Micron AFG / TJM, etc., Hosokawa Micron Hammer Mill, Fitzmill, Feather Mill, Inomizer, ACM Pulverizer, Turbo Industries Turbo Mill, Kawasaki It can be used for impact type pulverizers such as KTM manufactured by Heavy Industries Co., Ltd., Super Rotor manufactured by Nissin Engineering Co., Ltd., and Fine Mill manufactured by NPK.
As a classifier, it can be used in an airflow classifier such as a DS / DSX classifier manufactured by NPK, an elbow jet classifier manufactured by Nittetsu Mining Co., or a micron separator / ATP manufactured by Hosokawa Micron.
[0012]
After disassembling these toner manufacturing devices to some extent, sublimable solid pellets such as dry ice are accelerated with compressed air or high-pressure gas such as nitrogen or carbon gas, and the toner raw material or toner powder adhering to the machine wall, temperature It collides at high speed with toner deposits that are melted and fused by friction when they collide with the machine wall during transportation, and destroys and removes the deposits. Since the pellets sublimate and disappear after the deposits are removed, no in-machine contamination occurs due to the pellets themselves. Waste is also minimal because it is only adhering.
[0013]
The solid pellet that can be used at this time may be anything as long as it sublimes at room temperature. However, sufficient kinetic energy cannot be obtained without a certain density, so that effective cleaning cannot be performed. The density at −79 ° C. is preferably 1.3 g / cm ³ or more, particularly 1.5 g / cm ³ or more.
In addition, if the size of the solid pellet is too small, the inertial force is small, and if it is too large, the number of contact points with respect to the deposit is reduced, the pellet is destroyed during acceleration, and the energy required for acceleration is enormous. The effective size is about 0.5 to 5 mm in diameter, preferably 1.5 to 3.5 mm. The shape may be anything such as a cylindrical shape, a rectangular parallelepiped, or a spherical shape.
The higher the speed of accelerating the pellet, the more effective is the removal of deposits, and it is desirable that the speed at the impact surface be 200 m / s or higher, particularly 300 m / s or higher.
[0014]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited at all by the following examples, unless the summary is exceeded.
(Example)
100 parts by weight of styrene acrylate copolymer (softening point 145 ° C., glass transition point 64 ° C.)
Colorant Carbon Black MA100 6 parts by weight (Mitsubishi Chemical Corporation)
1 part by weight of low molecular polypropylene TP32 (manufactured by Sanyo Chemical Co., Ltd.)
Charge control agent Quaternary ammonium salt Bontron P-51 2 parts by weight (manufactured by Orient Chemical Co., Ltd.)
The flakes (average particle size around 300 μm) obtained by mixing, kneading and coarsely pulverizing were mixed with a jet type pulverizer (I-10 manufactured by Nippon Pneumatic Co., Ltd.) and a DS separator (DS-manufactured by Nippon Pneumatic Co., Ltd.). 10UR), a product group having an average particle size of 9.0 μm was obtained after pulverization and classification.
After that, the jet type pulverizer and DS separator are disassembled to some extent, and dry ice (solid carbon dioxide) with a diameter of 2.5 mm and a length of 3 mm is accelerated with compressed air at a pressure of 6.0 kgf / cm ² to collide with deposits in the machine. The cleaning work was carried out by removing them. The cleaning work time at this time was 1 hour, and the number of workers was one.
[0015]
(Comparative example)
For the above-described example, the cleaning operation was performed by a conventional operation in which suction by a vacuum cleaner and cleaning by a solvent were combined without using dry ice. The time required for the cleaning at this time was 4 hours, and the number of workers was 3, which required 10 times or more labor compared to the examples.
[0016]
【The invention's effect】
According to the present invention described above, it is possible to greatly reduce the labor required for cleaning the toner manufacturing apparatus, and since the organic solvent is not used, the safety is high and the industrial value of the present invention is remarkable.

Claims (4)

A cleaning method for a toner manufacturing apparatus, wherein a sublimable solid pellet collides with a wall surface of a toner manufacturing apparatus at a high speed to remove deposits made of a styrene resin on the wall surface. The density of the sublimable solid pellet at −79 ° C. is 1.3 g / cm. ³ Claims as described above 1 4. A method for cleaning the toner production apparatus according to 1. The size of the sublimable solid pellet is 0.5 to 5 mm in diameter. 1 Or a method for cleaning a toner production apparatus according to 2; The sublimable solid pellet is caused to collide with a collision surface at a speed of 200 m / s or more. 1 Any of ~ 3 1 The method for cleaning a toner production apparatus according to the item.