JP4244451B2 - Kneading extrusion apparatus and toner production method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a kneading and extruding apparatus for melt-kneading a composition containing a binder resin, a colorant, and a charge control agent, and more specifically, uniformly kneading a composition such as a toner used for electrophotographic image formation. The present invention relates to a kneading and extruding apparatus for forming a composition, a toner production method using this apparatus, and a toner produced with this apparatus.
[0002]
[Prior art]
A developing unit incorporated in an electrophotographic image forming apparatus such as a copying machine, a facsimile, or a laser printer is equipped with a sealed toner-filled container for supplying toner (toner powder), and this is a smooth flow. A characteristic toner is filled. In such an image forming apparatus, a toner used for developing a latent image is usually a powder in which additives such as a colorant and a charge control agent are uniformly mixed and dispersed in a binder resin (binder).
This toner is conventionally produced by processing a composition comprising a binder resin, a colorant, a charge control agent, etc. in each step of mixing, melt-kneading, cooling, pulverizing, and classification. Used to fill.
[0003]
In the series of toner manufacturing processes, in order to uniformly disperse the additive in the binder resin, conventionally, a kneading and extruding apparatus that mixes and disperses the binder resin in a melted state under heating has been used.
[0004]
After the melt-kneading step for uniformly dispersing as described above, the melt-kneaded product from the kneading and extruding apparatus is cooled and solidified to obtain a powdery toner. Regarding this cooling step, it is known that reaggregation in a kneaded composition such as a colorant and a charge control agent dispersed by kneading can be effectively prevented by quickly cooling the melt kneaded product. . Specific examples thereof are described in JP-A-7-152205 and JP-A-9-34173.
[0005]
However, in the method described in the above patent publication, although it is possible to obtain the effect of preventing re-aggregation, in order to instantaneously supply a high-temperature kneaded material of 100 ° C. or higher discharged from the kneading extrusion apparatus to the cooler and cooling the rolling, The kneaded composition adheres to or adheres to the rolling roll or cooling belt that is filled or circulated with a cooling solvent, and as a result, the toner quality varies due to the cooling variation of the kneaded composition. There was a problem that made it easier to do.
[0006]
Moreover, in the said rolling cooling process, since it aims at cooling a high temperature kneaded material to the inside, this is cooled in the thin film state. For this reason, the rolling roll and the cooling belt are easily damaged, and there is a problem that their lifespan is shortened.
[0007]
Adhesion or adhesion of the kneaded composition to the rolling roll or cooling belt not only lowers the cooling efficiency of the melt-kneaded material by the rolling roll or cooling belt, but also causes damage to these members. Therefore, in order to stabilize the toner quality and reduce the damage of the rolling roll and the belt, regular maintenance is required.
[0008]
[Problems to be solved by the invention]
The present invention is intended to solve the above problems, and its purpose is to prevent re-aggregation of the colorant and the charge control agent dispersed in the binder resin by the kneading extruder, and to maximize the above problems. A kneading and extruding apparatus capable of preventing the kneading composition from adhering to and sticking to a rolling roll or cooling belt, a method for producing toner using this apparatus, and a toner produced by this apparatus There is to do.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 (first invention) is a kneading extrusion apparatus provided with a primary cooling mechanism at an outlet from which a melt-kneaded product of a composition containing a binder resin, a colorant and a charge control agent is discharged. The primary cooling mechanism is disposed on a flat inclined receiving surface that receives and cools the discharged molten kneaded material, and on the back side of the inclined receiving surface, and the refrigerant acts by gravity. A refrigerant flow path 1 formed by a plurality of sections flowing in the opposite direction to the direction, a tubular refrigerant flow path 2 disposed on both sides of the inclined receiving surface, and flowing in a direction opposite to the direction in which the gravity acts, It is a kneading extrusion apparatus provided with the dewproof part which is arrange | positioned in the back side of the refrigerant flow path 1, has a block structure, and is filled with the dewproof material .
[0010]
In invention of Claim 1, since the melt-kneaded material discharged | emitted from the kneading extrusion apparatus is cooled by the primary cooling mechanism, and is cooled by the secondary cooling (rolling roll and cooling belt) of the next process after that, In contrast, the kneaded material is effectively prevented from sticking to and sticking to the rolling roll or cooling belt, which is a secondary cooling mechanism.
[0011]
During addition, the invention according to claim 1, in mixing kneading extrusion device, the primary cooling mechanism comprises an inclined receiving surface, the melt kneaded product to be discharged on the inclined receiving surface, falls while contacting therewith Primary cooling . Furthermore, in the first aspect of the invention, since the discharged melt-kneaded product is primarily cooled while falling on the inclined receiving surface while being in contact therewith, the melt-kneaded product is quickly cooled down by its own weight. Supplied to the secondary cooling mechanism.
[0012]
According to a second aspect of the present invention, in the kneading and extruding apparatus of the first aspect, the inclined receiving surface is controlled in a temperature range of −100 ° C. to 50 ° C. by the refrigerant supplied to the primary cooling mechanism.
[0013]
According to a third aspect of the present invention, in the kneading and extruding apparatus according to the first or second aspect, the refrigerant is a low-temperature refrigerant prepared by an ultra-low temperature air generator using a vortex tube principle.
[0014]
Invention of Claim 4 melt-kneads the composition containing binder resin, a coloring agent, and a charge control agent in the kneading-extrusion apparatus in any one of Claims 1-3, and this melt-kneaded material is A toner manufacturing method, wherein the toner for electrophotographic image formation is obtained by cooling with the primary cooling mechanism and then with the secondary cooling mechanism .
[0015]
According to a fifth aspect of the present invention, in the toner manufacturing method according to the fourth aspect, the secondary cooling mechanism is a rolling roll. This secondary cooling mechanism further includes a pulverization and classification process.
[0016]
According to a sixth aspect of the present invention, in the toner manufacturing method according to the fourth aspect, the secondary cooling mechanism is a cooling belt. This secondary cooling mechanism further includes a pulverization and classification process.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
First Embodiment FIG. 1 is a schematic explanatory view showing the configuration of a melt-kneading / cooling apparatus comprising a kneading and extruding apparatus equipped with a primary cooling mechanism and a secondary cooling mechanism provided in the subsequent stage. 2 is a front view of the primary cooling mechanism, and FIG. 3 is a right side view of FIG. 4 is a cross-sectional view taken along line AA of FIG. 2, that is, a cross-sectional view showing an internal structure of the primary cooling mechanism.
[0019]
The melt kneading / cooling apparatus shown in FIG. 1 includes a kneading extrusion apparatus 2 having a raw material charging hopper 1 at the front end and a primary cooling mechanism 3 at the rear end, and secondary cooling provided at the rear stage of the kneading extrusion apparatus. Mechanism 20. The secondary cooling mechanism 20 includes a rolling roll 5 and an endless cooling belt 6 that can circulate freely.
[0020]
As the primary cooling mechanism 3 that cools the high-temperature melt-kneaded material discharged from the kneading extruder 2, those shown in FIGS. 2 to 4 are preferable. Thereby, the melt-kneaded product from the kneading extruder 2 can be cooled smoothly and stably while naturally dropping.
[0021]
In the kneading and extruding apparatus of the present invention, the primary cooling mechanism has an upper block structure portion in which a large number of refrigerant flow paths through which refrigerant flows are formed on the back side of the inclined receiving surface, and a lower block structure filled with a dewproof material It is preferable to have a part. Further, it is preferable that the inclined receiving surface cools at least the lower surface and both side surfaces of the melt-kneaded product.
In addition, the inclination angle θ (FIG. 3) of the inclined receiving surface 4 of the primary cooling mechanism 3 is not particularly limited. However, the fluidity at the time of discharging the molten kneaded product and the melting on the inclined receiving surface 4 It can be set appropriately considering the cooling state of the kneaded product. In other words, the inclined receiving surface 4 is preferably installed at the discharge portion of the kneading extruder 2 so that the inclination angle θ can be appropriately adjusted.
[0022]
The inclined receiving surface 4 preferably cools at least the lower surface and both side surfaces of the melt-kneaded product, whereby the entire melt-kneaded product can be uniformly cooled. Therefore, in the present embodiment, as shown in FIGS. 2 to 4, the refrigerant flow path 11 is formed on the back side of the inclined receiving surface 4, and the refrigerant pipes 12 are provided on both sides of the inclined receiving surface 4. 2 to 4, reference numeral 8 denotes a refrigerant inlet, which is formed in a lower part of the inclined receiving surface 4 and a lower part of the refrigerant pipe 12. Reference numeral 9 denotes a refrigerant outlet, which is formed above each of the inclined receiving surface 4 and the refrigerant pipe 12. The temperature of the refrigerant 13 is controlled by an unillustrated refrigerant unit, and the refrigerant flow path 11 and the refrigerant pipe 12 are directed upward. It is designed to flow in a flow.
[0023]
Further, in the present embodiment, from the viewpoint of the cooling efficiency by the refrigerant 13, as shown in FIG. 4, the refrigerant flow path 11 is formed in a number of sections, and the dewproof material 10 is placed directly under these refrigerant flow paths. It is preferable to provide a filled dewproof material filling portion 14. Since the inclined receiving surface 4 is cooled, there is a concern that moisture in the atmosphere may condense and condensation may occur on the inclined receiving surface 4, but this problem can be avoided by the dewproof material filling unit 14. . When the condensation on the inclined receiving surface 4 is left as it is, it accompanies the kneaded composition, which may cause deterioration in toner quality. For the same reason, it is preferable to cover the outer surface of the refrigerant pipe 12 with the dewproof material 10 as shown in FIG.
[0024]
The inclined receiving surface 4 is controlled by the refrigerant 13 in a temperature range of −100 ° C. to 50 ° C., preferably −60 ° C. to 40 ° C. By doing so, the high-temperature melt-kneaded product from the kneading and extruding device does not adhere to or adhere to the inclined receiving surface 4. When the temperature of the inclined receiving surface 4 is lower than −100 ° C., although it depends on the type of the binder resin, it may be completely cured (solidified) and may not be formed into a thin sheet by the next roll. . Further, if the temperature exceeds 50 ° C., the cooling effect is reduced and sticking / adhesion occurs on the inclined receiving surface 4, making it difficult to transfer the kneaded composition to the next step (rolling roll, cooling belt), and toner quality. Variations may occur.
[0025]
As a method for preparing the refrigerant 13, for example, an ultra-low temperature air generator manufactured by Cosmic Co., which applies the principle of a vortex tube can be used, whereby a low-temperature refrigerant can be easily obtained at low cost.
[0026]
As the secondary cooling mechanism 20 having the rolling roll 5, a known one, for example, a belt type, a drum type or the like can be adopted. Examples of the kneading machine constituting the kneading and extruding apparatus 2 include a single-screw extruder, a twin-screw extruder, a roll-type kneader, and a screw-type kneader, and those capable of heating the inside are suitable.
[0027]
In the melt-kneading / cooling apparatus, the melt-kneaded product is primarily cooled while naturally falling on the inclined receiving surface 4 of the primary cooling mechanism 3, and the surface thereof is in a semi-cured state (semi-solid state). The semi-molten kneaded composition is formed into a thin sheet by the rolling roll 5 of the secondary cooling mechanism 20 without causing adhesion or sticking on the roll surface unlike the conventional apparatus. The composition 7 is cooled by releasing heat to the cooling belt 6 while being conveyed by the cooling belt 6. Therefore, according to the present embodiment, when the melt-kneaded product is cooled, it does not stick to or adhere to the rolling roll or the cooling belt, and the roll surface or the cooling belt surface is damaged by the stuck material of the melt-kneaded product. The problem of receiving is lost.
[0028]
This also causes partial re-aggregation, etc., which has tended to occur conventionally when the melt-kneaded material is a mixture of a melted resin component and a non-melted component, such as toner used in electrophotographic image formation. It can be prevented through the primary cooling process and the secondary cooling process. Therefore, the melt-kneading / cooling apparatus shown in FIG. 1 is suitable as a component of a toner production apparatus for forming an electrophotographic image containing a binder resin, a colorant, and a charge control agent. A high-performance toner production apparatus can be configured by combining with a subsequent pulverization / classification apparatus.
[0029]
Second Embodiment FIG. 5 is a schematic explanatory view showing the structure of a melt-kneading / cooling apparatus comprising a kneading and extruding apparatus 2 provided with a primary cooling mechanism 3 and a secondary cooling mechanism 20 provided at the subsequent stage. In this melt-kneading / cooling device, the belt driving roll for circulating the cooling belt 6 also serves as a rolling roll. Other configurations are the same as those in FIG.
[0030]
In the toner and the production method thereof according to the present invention, conventionally known binder resins or releasable resins, for example, styrene such as polystyrene, poly-p-styrene, and polyvinyltoluene, and polymers of substituted products thereof;
Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer Polymer, Styrene-acrylonitrile copolymer, Styrene-acrylonitrile copolymer, Styrene-vinyl methyl ether copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene- Styrenic copolymers such as maleic acid copolymer, styrene-maleic acid ester copolymer;
Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, epoxy resin, polyacrylic acid resin, rosin, modified rosin, chlorinated paraffin, paraffin wax, etc. alone or in combination Can be used.
[0031]
As the colorant, those known for toners are appropriately used. Examples of the black colorant include carbon black, aniline black, and furnace black.
Examples of cyan colorants include phthalocyanine blue, methylene blue, Victoria blue, methyl violet, aniline blue, and ultramarine blue.
Examples of the magenta colorant include rhodamine 6G lake, dimethylquinacridone, watching red, rose bengal, rhodamine B, alizarin lake and the like.
Furthermore, examples of the yellow colorant include chrome yellow, benzidine yellow, hansa yellow, naphthol yellow, molybdenum orange, quinoline yellow, and tartrazine.
These colorants are usually blended in the range of 5 to 15 parts by weight per 100 parts by weight of the binder resin.
[0032]
Furthermore, for example, a charge control agent is appropriately used in order to impart chargeability to the toner of the present invention more effectively. Examples of the charge control agent include metal complex salts of monoazo dyes, nitrohumic acid and salts thereof, metal complex salts such as salicylic acid, naphthoic acid, and dicarboxylic acid such as Co, Cr, and Fe, organic dyes, and quaternary ammonium salts. The charge control agent is blended in the range of 0.2 to 5 parts by weight, preferably 0.5 to 3 parts by weight per 100 parts by weight of the binder resin.
[0033]
If necessary, as additives for imparting smooth fluidity to the toner, for example, colloidal silica, metal oxide powders such as titanium oxide and aluminum oxide, lubricants such as fatty acid metal salts, and the like are blended. Is preferred. These additives may be supplied directly to the kneader together with the toner main components such as a binder resin, a colorant, and a charge control agent, or may be premixed as necessary, and pulverized by a conventionally known method. Can be mixed. For this purpose, for example, a super mixer, a Henschel mixer, a spindle kneader, a jet mill, a fine mill, a roll mill, an atomizer and the like can be appropriately selected and used.
[0034]
In the present invention, for example, a jet mill is preferably used to pulverize and classify the kneaded composition after cooling and solidification to obtain toner powder.
[0035]
【The invention's effect】
According to the present invention, the following effects can be obtained.
(1) Effect of the kneading and extruding device of claim 1 A primary cooling mechanism is provided at the outlet of the melt kneaded product, and the hot melt kneaded material discharged from the kneading and extruding device is changed directly into a rolling roll and a cooling belt. Instead of forming into a thin film (or thin sheet) after cooling in step 1, the primary cooling mechanism is used to cool the melted and kneaded product (in a semi-solid state), so it is deployed after the kneading extruder. It is possible to effectively prevent the kneaded composition from sticking to and sticking to the rolled roll and the cooling belt.
[0036]
Further, due to such an effect, damage to the rolling roll surface and the cooling belt surface caused by the sticking residue is remarkably reduced, and the maintenance complexity and the maintenance cost are reduced. Further, when the melt-kneaded product contains several kinds of components as in the toner composition, partial re-aggregation that tends to occur in the past is effectively prevented, and variation in toner quality is reduced. This has the effect of improving productivity .
In addition, since the melt-kneaded material is configured to be primarily cooled while falling on the inclined receiving surface of the primary cooling mechanism while in contact with the surface, the melt-kneaded material can be cooled quickly and more reliably. Can do. Moreover, the kneaded composition after the primary cooling can be supplied to the next step by its own weight. Furthermore, since at least the lower surface and both side surfaces of the melt-kneaded product are cooled by the effect inclined receiving surface by the kneading extruder, the entire melt-kneaded material on the inclined receiving surface can be cooled uniformly.
[0037]
(2) Effect of the kneading extrusion apparatus of claim 2
Since the inclined receiving surface is controlled in the temperature range of −100 ° C. to 50 ° C., the melt-kneaded product can be made into an appropriate semi-solid state, and thus the adhesion and adhesion of the melt-kneaded product can be prevented. In addition, it can be surely formed into a sheet by the rolling roll.
[0038]
(3) Effect of the kneading extrusion apparatus of claim 3
A low-temperature refrigerant can be obtained inexpensively and easily by using a low-temperature refrigerant prepared by an ultra-low temperature air generator using the vortex tube principle.
[0039]
(4) Effect of the toner manufacturing method of claim 4
A composition containing a binder resin, a colorant and a charge control agent is melt-kneaded in the kneading and extruding apparatus according to any one of claims 1 to 5, cooled by a primary cooling mechanism, and then kneaded from the kneading and extruding apparatus. Since the toner for forming an electrophotographic image is obtained by cooling the composition with a secondary cooling mechanism, it is possible to stably produce a toner with good quality.
[0040]
(5) Effect of the toner manufacturing method according to claim 5
Since the secondary cooling mechanism is a rolling roll, the melt-kneaded product can be reliably formed into a sheet.
[0041]
(6) Effect of the toner manufacturing method of claim 6
Since the secondary cooling mechanism is a cooling belt, the molten kneaded material can be reliably formed into a sheet shape.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing the configuration of a melt-kneading / cooling apparatus comprising a kneading-extruding apparatus according to a first embodiment of the present invention and a secondary cooling mechanism provided at the subsequent stage.
FIG. 2 is a front view of a primary cooling mechanism provided in the kneading and extruding apparatus of FIG.
FIG. 3 is a right side view of FIG. 2;
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is a schematic explanatory diagram showing a configuration of a melt-kneading / cooling device according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hopper 2 Kneading extrusion apparatus 3 Primary cooling mechanism 4 Inclined receiving surface 5 Roll roll 6 Cooling belt 7 Sheet-like kneading composition 8 Refrigerant inlet 9 Refrigerant outlet 10 Dew prevention material 11 Refrigerant flow path 12 Refrigerant piping 13 Refrigerant 14 Dew prevention Material filling unit 20 Secondary cooling mechanism

Claims (6)

A kneading and extruding apparatus provided with a primary cooling mechanism at an outlet from which a melt-kneaded product of a composition containing a binder resin, a colorant and a charge control agent is discharged,
The primary cooling mechanism is
A flat inclined receiving surface that receives and cools the discharged melt-kneaded product;
A first refrigerant flow path which is disposed on the back side of the inclined receiving surface and is formed of a plurality of sections in which the refrigerant flows in a direction opposite to the direction in which gravity acts;
A tubular second refrigerant flow path disposed on both sides of the inclined receiving surface and flowing in a direction opposite to the direction in which the gravity acts.
A dew proof portion disposed on the back side of the first refrigerant flow path, having a block structure and filled with a dew proof material;
A kneading and extruding apparatus comprising:   The kneading and extruding apparatus according to claim 1, wherein the inclined receiving surface is controlled in a temperature range of -100 ° C to 50 ° C by a refrigerant supplied to the primary cooling mechanism.   The kneading and extruding apparatus according to claim 1 or 2, wherein the refrigerant is a low-temperature refrigerant prepared by an ultra-low temperature air generator using a vortex tube principle.   A composition containing a binder resin, a colorant and a charge control agent is melt-kneaded in the kneading extrusion apparatus according to any one of claims 1 to 3, and the melt-kneaded material is cooled by the primary cooling mechanism. A toner production method comprising obtaining a toner for forming an electrophotographic image by cooling with a secondary cooling mechanism.   The toner manufacturing method according to claim 4, wherein the secondary cooling mechanism is a rolling roll.   The toner manufacturing method according to claim 4, wherein the secondary cooling mechanism is a cooling belt.

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