JP2007079472A - Toner supply conveyance device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner supply conveyance device by which a higher quality image is obtained by making cross section of a porous member larger in the downstream than in the upstream in order to prevent the flow rate in a conveyance path of toner from becoming uneven, transmitting the air to be transmitted to the inside of a toner storage part via the porous member in order to enhance fluidity of the toner, improving the fluidity of the toner in the toner storage part to convey the toner with high precision. <P>SOLUTION: A toner conveyance tube 100 is constituted by providing the porous member 21 comprised of a porous material, an air pump (air supply means) 24 for supplying the air via the porous member 21 and an air supply tube 26 which supplies the air of the air pump 24 to the porous member 21. A conveyance nozzle 22 and the porous member 21 are fitted by a nozzle fitting part 22a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner supply / conveyance device and an image forming apparatus, and more particularly to a toner supply / conveyance device used in an electrophotographic image forming apparatus such as a facsimile machine, a copying machine, or a complex machine thereof. is there.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a facsimile machine, or a printer, an image forming apparatus provided with a toner supply / conveyance device that conveys toner in a toner container to a conveyance tube provided with a movable member such as a screw auger. It has been known. In this toner supply and transfer device, the toner is vigorously rubbed between the movable member and the inner wall of the transfer tube to form a toner lump by softening. Therefore, the external additive on the surface is separated from the toner to change the dynamic physical properties of the toner. Sometimes adversely affected the image. In recent years, in order to keep the fixing temperature of a toner image by a fixing device as low as possible, a toner that softens at a lower temperature is used. Therefore, a toner lump, so-called secondary particles may be formed depending on the resin characteristics used for the toner. It tends to occur particularly easily.
In order to avoid such a problem, for example, in Patent Document 1 and Patent Document 2, as a means for conveying developer toner to a toner storage device such as a developing device or a toner replenishing tank attached thereto, a developing unit is used. A single-shaft eccentric screw (rotor) capable of transferring powder from toner storage means, toner supply means, and toner transfer means arranged at arbitrary positions without using a coil screw or the like as air-fuel mixture with air. ) Rotates in an elastic body (stator) having two spiral through-holes, thereby moving the air gap to generate pressure. Here, a technique for conveying toner using a pump or a screw pump that transfers a mixture of air and air by the generated pressure is disclosed.
According to this transport technology, in addition to the advantage that the transport interval can be extended during toner replenishment and the like, many advantages such as downsizing of the apparatus, simplification of the configuration, and improvement of operability during maintenance can be exhibited. it can. Specifically, as shown in FIG. 8, in the toner transfer means of the screw pump 211 using a Mono pump or the like capable of transferring powder by using toner as a mixture with air, the air used for toner transfer is the toner. It is positioned below the opening of the nozzle 213 for toner suction fitted in a sealed state to the lower part of the transport destination, that is, the toner containing container 212. The air flow is intermittently applied to the toner mass in the container from the opening 214 connected to the external air pump 218 to form a mixture of toner and air in the periphery of the nozzle 213, and the fluidity of the toner. In a state in which the toner is raised, a mixture of toner and air is guided to a toner discharge port to a toner conveyance path 215 provided in the vicinity of the nozzle. Further, the mixture of toner and air that has entered the toner conveyance path 215 is guided to the apparatus developing unit 216 by the suction function of the above-described Mono pump 211.
JP 2003-330218 A JP 2004-4394 A

According to the toner supply / conveying means described in Patent Documents 1 and 2, a mixture of toner and air is formed, and due to its fluidity, the load for supplying to the toner storage device is relatively low, and toner is contained. The problem that the amount of toner remaining in the container and ending in the unused state is solved. However, in the toner supply / conveying means, the gas supplied from the vicinity of the nozzles forms large bubbles in the toner mass. Due to the movement and rupture of the large bubbles in the toner mass, the toner mass in the vicinity of the nozzle is released and a mixture of toner and air is formed. Although the fluidity of this mixture is relatively high, it does not lead to the understanding of even the larger secondary particles formed by agglomeration of fine toner particles already present in the container. There is a problem that faithful image formation cannot be performed by being conveyed to a developing device) and used for developing an electrostatic latent image. This problem is particularly important in the case of high-definition image formation using a recent toner having a small particle diameter.
Further, there has been proposed a toner supply / conveying means for attaching a large toner-containing container to the outside of the image forming apparatus and supplying and conveying the toner in the toner-containing container to the developing mechanism of the image forming apparatus. However, also in this apparatus, the mechanism of the toner supply / conveyance means uses the same screw pump as in Patent Document 1 and Patent Document 2, and has the same problem as the toner supply / conveyance apparatus in Patent Document 1 and Patent Document 2. is there.
Further, in the method of sucking and transporting toner by the suction means, when the image forming apparatus is left unused for several days due to continuous holidays or the like, the toner is clogged in the transport hose so that the toner transport by the toner transport apparatus becomes impossible. There's a problem. This is because the staying toner is fixed in the transport pipe from the container to the developing unit and the subsequent toner transport is not executed smoothly when the period of time when the apparatus of the previous copy operation and the next copy operation is not operated becomes long. It is.

Further, in the image forming apparatus provided with the conventional toner supply / conveyance means, although the fluid made up of toner and air has appropriate fluidity, the path between the toner container and the toner storage device of the copying machine is too long, When the toner container is located at a lower position than the toner storage device of the copying machine, the toner conveyance response and the conveyance smoothness are lowered. For this reason, the layout of each unit in the copying machine may not be as desired, for example, the arrangement position of the toner container is limited.
Further, regarding the cause of clogging the conveyance hose, the bulk density of the toner flowing into the conveyance hose from the toner accommodating portion changes in the toner accommodating portion depending on the stirring state of the toner and the elapsed time after the stirring. The toner having a considerably high bulk density has a problem that it easily clogs in the transport hose.
For this reason, in the image forming apparatuses described in Patent Document 1 and Patent Document 2, a nozzle is provided in the toner container, and an air supply unit such as a blower that periodically supplies air to the nozzle is provided. ing. Then, the toner in the toner container is periodically agitated by blowing air from the nozzles, thereby preventing a situation in which the bulk density of the toner increases excessively.

However, even if the bulk density of the toner is decreased by blowing air, the bulk density of the toner in the toner storage unit may be immediately increased as the toner is sucked by the suction unit. This is because not only the toner particles existing around the toner suction port in the toner container and the air around the toner particles but also the air around the toner particles located relatively far from the toner suction port. This is because they also suck together. As a result of such suction, the air existing between the toner particles in the toner container is sucked preferentially over the toner, and as a result, the bulk density of the toner is immediately increased. Then, if the image forming apparatus main body is stopped with the toner having a high bulk density left in the transport hose and left for several days, adhesion between the toner particles increases and a large lump is formed, which is formed in the transport hose. There is a problem of clogging.
In addition, attempts have been made to increase the frequency of air blowing from the nozzles in order to suppress clogging of toner in the transport hose. However, even in this case, it is difficult to suppress clogging well. This is because the air blown out from the nozzles does not uniformly reach the inside of the toner accommodating portion, and there is a place where the air does not necessarily spread. As a result, the toner with increased bulk density flows into the transport hose, and if the image forming apparatus main body is left in the transport hose for several days, it becomes a large lump and clogs in the transport hose. There is.

Further, the toner replenishment by the uniaxial eccentric pump described above is proportional to the rotational speed of the rotor and the weight of the conveyed toner, but in the region where the replenishment time (replenishment amount) is small, the linearity is lost as shown in FIG. growing. This phenomenon is due to an increase in the variation in the amount of toner that is supplied by the rotor once, and the effect increases as the bulk density of the toner decreases. Details are described below. The rotor directly receives ON / OFF of the output of the motor through only the gear, or starts / stops rotation by receiving ON / OFF of the clutch through the clutch. The amount of rotation is expected to be proportional to the time of the control signal for controlling ON / OFF of the motor or clutch. However, because of the structure of the motor and clutch, it is necessary to allow for non-rotation time such as rotation delay due to sliding load. In addition, the non-rotation time varies depending on the sliding load of each motor and clutch, and varies depending on the sliding load over time. It is difficult to control the same uniformly, and the expected amount is also large. It must be a rough one with variations.
If the bulk density of the toner is high under such a premise, even if there is a variation due to the non-rotation time with respect to the total rotation amount corresponding to one replenishment, the influence is small because the entire replenishment amount is large. However, when the bulk density of the toner is low, if the rotation speed (rotation time) of the rotor is reduced, the ratio of the non-rotation time variation to the total rotation amount becomes large, and the replenishment variation becomes remarkable. Therefore, it can be said that a very small amount of replenishment control is a difficult task even with a screw pump.
In view of the above problems, the present invention is to increase the cross-sectional area of the porous member downstream from the upstream side and to increase the fluidity of the toner in order to prevent the flow velocity in the toner conveyance path from becoming non-uniform. Provides a toner supply / conveying device that sends air into the toner container through a porous member, improves the fluidity of the toner in the toner container, conveys the toner with high accuracy, and obtains a higher quality image. The purpose is to do.

In order to solve the above-described problems, the present invention includes a toner storage portion that stores toner and a toner introduction port for discharging the toner in the toner storage portion, and the toner is discharged from the toner introduction port. A toner supply / conveying device that supplies toner from the toner containing portion to the developing means of the image forming apparatus, and is provided as a part of a conveying path by the conveying tube. A porous member made of a material, and an air feeding means for sending air toward the inside of the transport pipe, and by sending air into the transport pipe through the porous member by the air feeding means, It is characterized in that the toner transported in the transport tube is fluidized to reduce the bulk density.
A feature of the present invention is that a porous member is disposed as a part of the path of the toner transport pipe, and air is supplied to the porous member by an air supply means so that the inflowed air is finely foamed from the porous member. It erupts as an air layer. As a result, the toner is finely separated to increase the fluidity, and sent to the developing device.
According to a second aspect of the present invention, the air feeding means feeds air through the porous member so as to be substantially orthogonal to the transport direction of the toner transported in the transport pipe.
A path made of a porous member is provided in the vicinity of the exit of the transport path, and air is sent in by a separately provided air pump. At this time, the air flow direction is configured to be substantially orthogonal to the toner conveyance direction. The toner is fluidized by the supplied air and the bulk density is lowered. Furthermore, let the air that has been sent escape from the opposite side.

According to a third aspect of the present invention, the cross-sectional area on the outflow side of the porous member is made larger than that on the inflow side of the toner.
The toner fluidized by the air that has been sent in has a reduced bulk density and therefore an increased volume. Therefore, if the amount of toner passing is constant, the volume of the toner increases due to fluidization, so that the flow velocity in the transport path increases. However, it has been found from experiments that toner clogging is likely to occur in the path when the flow velocity is uneven in the transport path. Therefore, in order to make the flow velocity in the transport pipe close to uniform, the cross-sectional area of the porous member is made larger in the downstream section than in the upstream section, which has a great effect on the stability of transport and prevention of toner clogging in the transport pipe. give.
According to a fourth aspect of the present invention, a suction pump is used as the means for conveying the toner.
It is conceivable to use a suction type pump as a toner conveying means. As a result, the relationship between the developing device and the toner replenishing device in the image forming apparatus can be freely arranged, and the degree of freedom in layout is greatly improved, so that the space of the apparatus can be saved.
According to a fifth aspect of the present invention, the suction pump is a uniaxial eccentric screw pump.
As a suction type pump, a single-shaft eccentric screw pump comprising a rotor having a single cylindrical convex portion in a cylindrical shape and a stator having two helical grooves in a cylindrical shape has high replenishment resolution. Functionally suitable because the minimum supply time can be shortened.
According to a sixth aspect of the present invention, a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port.
Furthermore, in the toner storage container, a replenishing device has been put into practical use for the purpose of enhancing the toner fluidity by sending air and using the toner in the container to the end.

According to a seventh aspect of the present invention, a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, and the air injected from the path is sent to the toner accommodating portion through the porous member. Features.
A method of using a porous member when air is fed into the toner storage device is conceivable. By this means, air can be sent to the toner in the entire storage device, and the entire toner can be fluidized.
According to an eighth aspect of the present invention, an image forming apparatus includes the toner supply / conveyance device according to any one of the first to seventh aspects.
By providing the toner supply / conveyance device according to any one of claims 1 to 7 in the image forming apparatus, toner deterioration in a high-temperature / high-humidity environment can be prevented, and the fluidity of the toner in the toner storage portion can be prevented. As a result, the toner can be conveyed with high accuracy and a higher quality image can be obtained.
According to a ninth aspect of the present invention, in the toner container, a toner composition comprising at least a prepolymer, a colorant, and a release agent is dispersed in an aqueous medium in the presence of resin fine particles, and the toner composition is subjected to a polyaddition reaction. The toner thus obtained is contained.
As an advantage of the polymerized toner, there is no pulverization step, and resources can be saved. The diameter distribution is sharp. The charge distribution is sharp. Shape control that changes the circularity is easy. Etc. As a result, a high-quality image can be obtained, and the output can be stabilized by the combination with the porous member described above.

According to the first aspect of the present invention, the dispersibility of the toner in the developing device is improved by mixing air with the toner and supplying the toner to the developing device with a low bulk density near the end of the toner conveyance path, It is possible to reduce density unevenness by stabilizing the toner density in the developing machine. At the same time, the charging characteristics can be improved by improving the dispersibility, and problems such as toner scattering and background smearing can be solved by uniformly charging the toner.
Further, in the present invention, the air supply means is configured so that the direction of the air flowing through the porous member is substantially orthogonal to the transfer direction of the toner transferred in the transfer tube. Fluidized to reduce bulk density.
Further, in claim 3, by making the cross-sectional area of the porous member larger than the upstream side of the conveyance path, the flow rate in the conveyance path is made close to a constant value corresponding to the increase in the volume of the fluidized toner. It is possible to prevent toner clogging in the conveyance path.
According to the fourth aspect of the present invention, since the suction pump is used as the means for conveying the toner, the degree of freedom in the layout of the entire apparatus can be increased, and the apparatus can be downsized.
According to the fifth aspect of the present invention, since the suction pump is a uniaxial eccentric screw pump, it is possible to achieve highly accurate toner replenishment, and a stable output can be obtained by using the fluidized toner using a porous member. An image can be obtained.
According to the sixth aspect of the present invention, since a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, it is possible to minimize the supply of air in the transport path, and clog the toner in the transport path. Can be prevented.
According to a seventh aspect of the present invention, a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, and the air injected from the path is sent to the toner accommodating portion through the porous member. Since the entire toner can be fluidized, the effect of minimizing the supply of air in the conveyance path can be further enhanced.
According to an eighth aspect of the present invention, since the image forming apparatus includes the toner supply / conveyance device according to any one of the first to seventh aspects, it is possible to obtain a stable image output with high image quality.
According to the ninth aspect of the present invention, in the toner container, a toner composition comprising at least a prepolymer, a colorant, and a release agent is dispersed in an aqueous medium in the presence of resin fine particles, and the toner composition is subjected to a polyaddition reaction. Since the obtained toner is accommodated, a high-quality image can be obtained, and the output can be stabilized by the combination with the porous member described above.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus (printer) according to the present invention.
The image forming apparatus 90 includes four toner image recording units 1Y, 1M, 1C, and 1K for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K). The optical writing unit 2, the paper feed cassettes 3 and 4, the registration roller pair 5, the transfer unit 6, the belt fixing type fixing unit 8, the paper discharge tray, and the like. Further, a manual feed tray, a toner supply container, a waste toner bottle, a power supply unit and the like (not shown) are also provided. Hereinafter, the subscripts Y, M, C, and K of the respective symbols indicate members for yellow, magenta, cyan, and black, respectively.
The toner image recording units 1Y, 1M, 1C, and 1K include drum-shaped photoreceptors 11Y, 11M, 11C, and 11K that are electrostatic latent image carriers that carry latent images. These photoreceptors 11Y, 11M, 11C, and 11K are rotationally driven clockwise in FIG. 1 by driving means (not shown), respectively, to move their surfaces endlessly. Then, it is optically scanned in the dark by an optical writing unit 2 that emits a laser beam L modulated based on image information sent from a personal computer (not shown) or the like, and electrostatic latent images for Y, M, C, and K are obtained. Carry an image.

FIG. 2 is a cross-sectional view showing a part of the toner conveying tube according to the first embodiment of the present invention. The toner conveying tube 100 includes a porous member 21 made of a porous material, an air pump (air supply means) 24 for sending air through the porous member 21, and air from the air pump 24 to the porous member 21. And an air supply pipe 26 to be sent to. And the conveyance nozzle 22 and the porous member 21 are fitted by the nozzle fitting part 22a.
Here, as shown in FIG. 2, a path made of the porous member 21 is provided in the vicinity of the exit of the transport path, and the air 20 is sent by the air pump 24 provided separately. The toner 20 is fluidized by the fed air 20 and the bulk density is lowered. Further, as shown in FIG. 2, the air 20 that has been sent escapes from the opposite side of the path formed by the porous member 21. Moreover, the porous member 21 used here is a fine porous member through which air can pass, and the aperture ratio of the porous member is preferably 5 to 40%, more preferably 10 to 20%. Further, since the toner generally has a volume average particle diameter of 3 to 15 μm, the average opening diameter of the porous member is preferably 0.3 to 20 μm, more preferably 5 to 15 μm. Further, the average pore diameter of the pores of the porous member is preferably 0.1 to 5 times, more preferably 0.5 to 3 times the volume average particle diameter of the toner to be supplied and conveyed.
Moreover, there is no restriction | limiting in particular as a material of a porous member, According to the objective, it can select suitably. For example, porous resin materials such as glass, resin particle sintered body, photo-etched resin, thermally perforated resin, etc .; metal sintered body, perforated metal plate-like material, net laminate By heating a copper plate prepared by depositing metallic copper around an easily fusible metal yarn bundle by an electrochemical method and through which the easily fusible metal yarn bundle is embedded, the easily fusible metal yarn Examples thereof include a metal material having a selective melt trace hole having a trace hole part from which a part has been selectively removed.

FIG. 3 is a cross-sectional view showing a part of a toner conveying tube according to the second embodiment of the present invention. The same components will be described with the same reference numerals as in FIG. The toner transport tube 110 includes a porous member 28 made of a porous material, a transport nozzle 22 having a small diameter, and a transport nozzle 27 having a large diameter. And the porous member 28 is fitted by the nozzle fitting parts 22a and 27a. In this figure, an air pump (air supply means) 24 and an air supply pipe 26 for sending air from the air pump 24 to the porous member 28 are not shown.
As described above, since the toner fluidized by the air fed in has a reduced bulk density, its volume increases. Therefore, if the amount of toner passing is constant, the volume of the toner increases due to fluidization, so that the flow velocity in the transport path increases. However, it has been found from experiments that toner clogging is likely to occur in the path when the flow velocity is uneven in the transport path. Therefore, in order to make the flow velocity in the transport pipe close to uniform, making the cross-sectional area of the porous member 28 larger than the upstream portion has a great effect on the stability of transport and preventing toner clogging in the transport pipe. . As a specific shape, the cross-sectional area is increased from the middle of the path as shown in FIG. 3, or the porous member 29 is tapered as shown in FIG.
FIG. 5 is a cross-sectional view of the suction pump. This suction pump 130 is a uniaxial eccentric screw pump, a so-called MONO pump, comprising a rotor 42 provided with one spiral convex portion in a cylindrical shape and a stator 41 provided with two spiral grooves in a cylindrical shape. Because it has a high replenishment resolution, it can be functionally suitable because the minimum replenishment time can be shortened. In the case of this pump, as described above, in the case of toner having a high bulk density and a small degree of fluidization, the replenishment resolution is low and the variation is large. Therefore, high resolution and stable toner replenishment can be performed by combining the use of a porous member near the end of the toner replenishment path and fluidizing the toner. Further, as shown in FIG. 1, by using a suction type pump as a toner conveying means, the relationship between the developing device and the toner replenishing device in the image forming apparatus can be freely arranged, and the degree of freedom in layout is great. By improving, it becomes possible to save the space of the apparatus.

FIG. 6 is a cross-sectional view of a toner conveying tube according to the third embodiment of the present invention. The toner transport tube 140 includes an air inlet 33 for injecting air 37, an air supply path 32 for sending air to the toner storage unit 30, a toner discharge port 31, and a toner transport port 35. Then, by injecting air 37 from the air injection port 33, the air 37 is sent into the toner container 30 via the air supply path 32. As a result, the fluidity of the toner is enhanced, and the toner passes through the toner transport pipe 140 from the toner discharge port 31 and is sent from the toner transport port 35 to a developing device not shown.
Thus, the toner fluidized once in the toner storage unit 30 is easily fluidized in the porous member described with reference to FIGS. As a result, it is possible to reduce the amount of air sent to the porous member by using both the device for feeding the air 37 to the toner storage unit 30 and the toner fluidization by the porous member in the conveying path. It is possible to prevent toner clogging in the conveyance path due to excessive supply.
FIG. 7 is a cross-sectional view of a toner conveying tube according to the fourth embodiment of the present invention. The same components will be described with the same reference numerals as in FIG. The toner transport pipe 150 includes an air inlet 33 for injecting air 37, an air supply path 32 for sending air to the toner storage unit 30, a porous member 38, a toner discharge port 31, and a toner transport port 35. Configured. Then, by injecting air 37 from the air injection port 33, the air 37 is sent into the toner containing portion 30 through the air supply path 32 and the porous member 38. As a result, air can be sent to the toner in the entire toner storage unit 30 and the entire toner can be fluidized.

A high-quality image can be obtained by stable toner replenishment by using any of the toner transport pipes shown in FIGS. 2 to 7 in the image forming apparatus.
Further, a so-called polymerized toner manufactured as described below is used as the toner. However, the toner manufacturing method is not limited to the following. Generally, the toner replenishment amount of the polymerized toner is increased by about 10 to 40% as compared with the pulverized toner having the same particle diameter. This is because the toner shape is close to a sphere, and the toner tends to become dense, and the stability of the replenishment amount is lower than that of the pulverized toner. However, with respect to the image, since the particle size distribution is sharp and the charging characteristics are good, an image with higher image quality than the pulverized toner can be obtained.
Therefore, it is possible to stably obtain a high-quality image by using a porous member for the polymerized toner and supplying the developing device in a fluidized state by the above-described means.
Hereinafter, a toner manufacturing method will be described.
(1. Preparation of toner composition) A toner raw material composed of a resin, a colorant, a wax, a charge control agent, and a polyester resin having an isocyanate group (prepolymer) is dissolved in an organic solvent such as ethyl acetate, and the toner composition is prepared. It is a thing. (Prepolymer refers to a polymer having two or more reactive groups in one molecule of the base polymer.)
(2. Emulsification) The toner composition and amines are added to an aqueous medium containing a surfactant, a viscosity modifier, and resin fine particles, and dispersed by shearing force to form an emulsified state.
(3. Aging) In order to promote the elongation and / or crosslinking reaction due to the reaction between the isocyanate group and the amine, the reaction system is heated.
(4. Desolvation) As an example, a method of gradually raising the temperature of the entire system and evaporating and removing the organic solvent in the droplets can be employed.
(5. Alkaline washing, water washing) This is a process for removing foreign matters (surfactant, viscosity modifier, etc.) remaining on the surface of the obtained toner particles.
(6. Drying) The obtained toner particles are collected by filtration and dried.
(7. External additive treatment) If necessary, external additive fine particles (silica, titania, alumina, etc.) are externally added by a 0.1 to 5.0 parts by weight mixer.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Below, a part represents a weight part.
<Example of toner production>
(Production example of polyester) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 690 parts of bisphenol A ethylene oxide 2-mol adduct and 256 parts of terephthalic acid were polycondensed at 230 ° C. for 8 hours under normal pressure. Next, the mixture was reacted at a reduced pressure of 10 to 15 mmHg for 5 hours and then cooled to 160 ° C., and 18 parts of phthalic anhydride was added thereto and reacted for 2 hours to obtain unmodified polyester (a).
(Prepolymer production example) 800 parts of bisphenol A ethylene oxide 2-mole adduct, 180 parts of isophthalic acid, 60 parts of terephthalic acid, and 2 parts of dibutyltin oxide in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe The reaction was carried out for 8 hours at 230 ° C. under normal pressure, and further for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, then cooled to 160 ° C., and 32 parts of phthalic anhydride was added thereto for 2 hours. did. Next, the mixture was cooled to 80 ° C. and reacted with 170 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate group-containing prepolymer (1).
(Production Example of Ketimine Compound) 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirrer and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (2).

(Toner Production Example) 15.4 parts of the above prepolymer (1), 60 parts of polyester (a) and 78.6 parts of ethyl acetate were placed in a beaker and dissolved by stirring. Next, 10 parts of rice WAX (melting point 83 ° C.) as a release agent and 4 parts of copper phthalocyanine blue pigment (cyan pigment) were added and stirred at 12,000 rpm using a TK homomixer at 60 ° C., and dissolved uniformly. Dispersed. Finally, 2.7 parts of ketimine compound (2) was added and dissolved. This is designated as toner material solution (3). In a beaker, 306 parts of ion-exchanged water, 265 parts of a 10% calcium phosphate suspension, 0.2 part of sodium dodecylbenzenesulfonate, and styrene / acrylic resin fine particles having an average particle diameter of 0.20 μm were uniformly dissolved. Next, the temperature was raised to 60 ° C., and the toner material solution (3) was added while stirring at 12000 rpm with a TK homomixer and stirred for 10 minutes. Next, 500 g of this mixed solution was weighed and transferred to a Kolben equipped with a stirrer and a thermometer in the same manner as in Example 1, and the temperature was raised to 45 ° C., and the solvent was removed over 0.5 hours while performing a urea reaction under reduced pressure. After filtering, washing and drying, air classification was performed to obtain base particles.
100 parts of base particles and 0.25 part of charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) are charged into a Q-type mixer (manufactured by Mitsui Mining Co., Ltd.), and the peripheral speed of the turbine blade is set to 50 m / sec. A 5-minute operation and a 1-minute pause were performed for a total treatment time of 10 minutes. Further, 0.5 part of hydrophobic silica (H2000, manufactured by Clariant Japan Co., Ltd.) was added, the peripheral speed was 15 m / sec, mixing was performed for 30 seconds and suspended for 1 minute for 5 cycles to obtain a cyan toner. Subsequently, 100 parts of toner particles were mixed with 0.5 part of hydrophobic silica and 0.5 part of hydrophobic titanium oxide using a Henschel mixer to obtain the toner of the present invention.
* Change only the "copper phthalocyanine blue pigment (cyan pigment) 4 parts" to make other color toners.
For making yellow toner, 6 parts for benzidine yellow pigment, for magenta toner, 6 parts for rhodamine lake pigment, for black toner, 10 parts for carbon black

As described above, according to the present invention, near the end of the toner conveyance path, air is mixed into the toner and the toner is supplied to the developing device in a low bulk density state, thereby improving the dispersibility of the toner in the developing device, It is possible to reduce density unevenness by stabilizing the toner density in the developing machine. At the same time, the charging characteristics can be improved by improving the dispersibility, and problems such as toner scattering and background smearing can be solved by uniformly charging the toner.
In addition, since the air supply means is configured so that the direction of the air flowing through the porous member is substantially perpendicular to the direction of the toner transported in the transport pipe, the toner is fluidized and bulked by the air fed in. Density can be reduced.
In addition, by making the cross-sectional area of the porous member larger than the upstream side of the conveyance path, the flow rate in the conveyance path is made constant by making it correspond to the increase in the volume of the fluidized toner, and in the conveyance path. It becomes possible to prevent toner clogging.
Further, since the suction pump is used as the means for conveying the toner, the degree of freedom in the layout of the entire apparatus can be increased, and the apparatus can be downsized.

Further, since the suction pump is a uniaxial eccentric screw pump, it is possible to achieve highly accurate toner replenishment, and a stable output image can be obtained by using in combination with toner fluidized using a porous member. Is possible.
In addition, since a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, it is possible to minimize the supply of air in the transport path and prevent clogging of the toner in the transport path. It becomes possible.
Further, a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, and the air injected from this path is configured to be sent to the toner accommodating portion through the porous member, so that the entire toner inside the container is Since the fluid can be fluidized, the effect of minimizing the supply of air in the conveyance path can be further enhanced.
In addition, since the image forming apparatus includes the toner supply / conveyance device according to any one of claims 1 to 7, it is possible to obtain a stable image output with high image quality.
In the toner container, a toner composition obtained by dispersing a toner composition comprising at least a prepolymer, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles, and subjecting the toner composition to a polyaddition reaction. Therefore, it becomes possible to obtain a high-quality image, and the output can be stabilized by the combination with the porous member described above.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus (printer). FIG. 3 is a cross-sectional view illustrating a part of the toner conveyance tube according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view (part 1) illustrating a part of a toner conveyance tube according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view (part 2) illustrating a part of a toner conveyance tube according to a second embodiment of the present invention. It is sectional drawing of a suction type pump. FIG. 6 is a cross-sectional view of a toner transport tube according to a third embodiment of the present invention. FIG. 6 is a cross-sectional view of a toner transport tube according to a fourth embodiment of the present invention. It is a figure which shows the toner transfer means of the screw pump which uses the conventional Mono pump etc. FIG. 6 is a diagram illustrating a relationship between a toner replenishment amount and a replenishment time.

Explanation of symbols

  21 Porous member, 22 Conveying nozzle, 22a Nozzle fitting part, 24 Air pump (air supply means), 26 Air supply pipe, 30 Toner storage part, 31 Toner discharge port, 32 Air supply path, 33 Air injection port, 35 Toner Conveying port, 37 air, 100 toner conveying tube

Claims (9)

A toner container that contains toner, and a transport pipe that includes a toner inlet for discharging the toner in the toner container and that transports the toner discharged from the toner inlet. A toner supply / conveying device that supplies toner to developing means of an image forming apparatus,
A porous member that is arranged as a part of a transport path by the transport pipe and is made of a porous material, and an air feeding means that sends air toward the inside of the transport pipe,
A toner supply / conveyance device, wherein the air density is lowered by flowing air into the conveyance pipe through the porous member by the air feeding means to fluidize the toner conveyed in the conveyance pipe.   The toner supply / conveyance device according to claim 1, wherein the air supply unit sends air through the porous member so as to be substantially orthogonal to a conveyance direction of the toner conveyed in the conveyance tube.   3. The toner supply / conveyance device according to claim 1, wherein a cross-sectional area of the porous member on the outflow side is larger than that on the inflow side of the toner.   The toner supply / conveyance apparatus according to claim 1, wherein a suction pump is used as the means for conveying the toner.   The toner supply / conveyance device according to claim 4, wherein the suction pump is a uniaxial eccentric screw pump.   The toner supply / conveyance device according to claim 1, wherein a path for injecting air from the air supply unit is formed in the vicinity of the toner discharge port.   A structure is provided in which a path for injecting air from the air supply means is formed in the vicinity of the toner discharge port, and the air injected from the path is sent to the toner accommodating portion through the porous member. The toner supply / conveyance device according to any one of 1 to 5.   An image forming apparatus comprising the toner supply / conveyance device according to claim 1.   A toner obtained by dispersing a toner composition comprising at least a prepolymer, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles and subjecting the toner composition to a polyaddition reaction in the toner container. The image forming apparatus according to claim 8, further comprising:

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