JP4915866B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing device for fixing toner used for image formation or the like and other resin-containing fine particles to a medium using a fixing liquid, and in particular, a structure in which the fixing liquid is formed into a foam and contacted to resin-containing fine particles such as toner. The present invention relates to a fixing device and an image forming apparatus using the same.

  Image forming apparatuses such as printers, facsimiles, and copiers form images including characters and symbols on recording media such as paper, cloth, and OHP sheets based on image information. In particular, electrophotographic image forming apparatuses are widely used in offices because they can form high-definition images on plain paper at high speed.

  In an electrophotographic image forming apparatus, a heat fixing method is widely used in which toner on a recording medium is heated and melted, and the toner is fixed on the recording medium by pressurizing the melted toner. This thermal fixing method can realize a high fixing speed and a high fixed image quality. However, the heat fixing method consumes a large amount of power, and about half or more of the power consumption in the electrophotographic image forming apparatus is consumed for heating the toner for fixing.

  In recent years, a fixing device with low power consumption (energy saving) has been desired from the viewpoint of environmental measures. That is, a fixing method in which the temperature at which the toner is heated to fix the toner is extremely lowered than before, and a fixing method in which the toner is not heated are desired. In particular, the non-heat fixing method in which the toner is fixed to the recording medium without heating the toner at all is ideal in terms of low power consumption.

  As the non-heat fixing method, for example, an oil-in-water fixing agent in which an organic compound that can dissolve or swell toner and in which water is insoluble or hardly soluble is dispersed and mixed in water is used as an unfixed toner on a recording medium. Patent Document 1 discloses a wet fixing method in which a toner is dissolved or swollen by spraying or dripping and then dried.

  However, since this wet fixing method uses an oil-in-water type fixing agent in which an organic compound insoluble or hardly soluble in water is dispersed and mixed in water, a large amount of fixing agent is applied to unfixed toner. However, there is a problem that a recording medium (non-fixed material) such as transfer paper absorbs moisture of the fixing agent, and the recording medium is wrinkled and curled. Therefore, if water is removed from the fixing agent applied to the recording medium by evaporating a large amount of water contained in the fixing agent using a drying device, the power consumption of the image forming apparatus using the thermal fixing method is reduced. Comparable power is required and power saving cannot be achieved.

  Further, as a fixing solution that does not repel water-repellent unfixed toner, an oil-based fixing solution in which a material that dissolves or swells the toner in an oil-based solvent has been proposed. One of them is disclosed in Patent Document 2 related to the applicant's patent application. This fixing solution is obtained by diluting (dissolving) a material component for dissolving or swelling a resin component constituting the toner in water. Patent Document 2 discloses that in an electrophotographic image forming apparatus, such a fixing solution is applied to unfixed toner on an intermediate transfer belt subjected to a liquid repellent treatment, and almost no power is required for drying. A fixing device is disclosed.

  Patent Document 2 also discloses a fixing device having a configuration in which a fixing solution is ejected in the form of bubbles from a nozzle, and the foam-like fixing solution is directly applied to the toner on the intermediate transfer belt subjected to the liquid repellent treatment. It is disclosed. Such a configuration has an advantage that the amount of the fixing liquid adhered to the toner can be reduced.

Japanese Patent No. 3,290,513 JP 2004-109747 A

  In the method of applying the fixing liquid to the unfixed toner layer in the liquid state, for example, as shown in FIG. 25, the unfixed toner layer on the recording medium passing between the application roller and the pressure roller is attached to the application roller. When the fixer is applied, if the thickness of the fixer layer on the applicator roller is thinner than the unfixed toner layer, the surface tension generated by the fixer liquid film on the applicator roller surface when the applicator roller peels from the recording medium. As a result, unfixed toner particles are pulled, and the toner particles adhere to the surface of the application roller, and the image on the recording medium is greatly disturbed. FIG. 26 is an explanatory diagram of such toner adhesion.

  Conversely, if the thickness of the fixing liquid layer on the application roller is sufficiently thicker than that of the unfixed toner layer, the surface tension of the application roller surface due to the liquid film is large because of the large amount of liquid when the application roller peels from the recording medium. It becomes difficult to act on the toner particles, and the toner does not adhere to the roller side. However, since a large amount of the fixing solution is applied to the paper surface, the toner particles are caused to flow by the excessive fixing solution on the recording medium, resulting in deterioration of image quality, and the drying time becomes long, causing a problem in fixing responsiveness. In addition, a noticeable residual liquid feeling (a wet feeling when the paper is touched by hand) occurs on the paper. In addition, when the fixing solution contains water, a medium containing cellulose such as paper curls remarkably, and there is a risk of paper jam occurring during conveyance of the medium such as paper in the apparatus in an image forming apparatus.

  As described above, in the configuration in which the fixing liquid is applied with the roller, it is extremely difficult to simultaneously achieve the fixing responsiveness, the residual liquid feeling, the curling of the medium, and the toner adhesion to the fixing roller. Even when a die coating means other than a coating roller, a blade coating means, or a wire bar coating means is used as the contact coating means, if the amount of the fixer becomes very small, toner adheres to the contact coating means due to surface tension, resulting in image degradation. Occurs.

  As described above, the problem has been described with respect to fixing unfixed toner on a recording medium such as paper. However, there is a similar problem in the case where liquid fixing liquid is applied to resin-containing fine particles other than the toner to fix the toner.

  In order to improve the above-described problems, the present invention has a novel configuration in which a fixing solution is not used in a liquid state but is fixed by applying a foam-like fixing solution to resin-containing fine particles such as toner. It is an object to provide an apparatus and an image forming apparatus using the apparatus.

  The fixing device of the present invention includes a roller-shaped or belt-shaped coating member and a pressure member for pressing the medium against the coating member, and passes between the coating member and the pressure member. A foam-type fixing liquid film containing a softening agent that softens a resin containing fine particles such as toner formed on the coating member is pressed against fine particles such as unfixed toner on the medium. A fixing liquid applying unit is used, and the structure and operation are basically different from those of the fixing apparatus of Patent Document 2 that directly applies the foamy fixing liquid discharged from the nozzle to the toner.

Now, in the fixing liquid applying means as described above, as will be described in detail later, in order to efficiently penetrate the fixing liquid into the fine particle layer such as toner until reaching the medium, a coating member such as toner is also used. In order to prevent adhesion to the coating member, it is desirable that the thickness of the foam-like fixing liquid film formed on the coating member is equal to or greater than the thickness of the fine particle layer such as toner. Therefore, a part of the foam-like fixing liquid on the application member remains on the application member without adhering to the fine particle layer such as toner. Since the foam-like fixing solution has a large bulk (bulk), for example, even if a few percent remains, if the remaining foam-like fixing solution is left as it is, normal fixing operation may be hindered or surroundings may be contaminated.
Therefore, one of the specific problems to be solved by the present invention is to prevent the adverse effect of the foam-like fixing liquid remaining on such an application member.

  Other specific problems to be solved by the present invention will be described later.

The invention according to claim 1 provides a fixing device having a novel configuration for fixing fine particles containing unfixed resin on a medium to the medium, and the characteristics of the fixing device are as follows:
A roller-shaped or belt-shaped coating member; and a pressure member for pressing the medium against the coating member, the unfixed fine particles on the medium passing between the coating member and the pressure member On the other hand, a fixing solution applying means for pressing a film of a foam-like fixing solution formed on the coating member and containing a softening agent that softens the resin;
And defoaming means for defoaming and re-liquefying the foam-like fixing solution remaining without adhering to the fine particles on the coating member.

  According to a second aspect of the invention, in addition to the configuration of the fixing device according to the first aspect of the invention, there is provided a fixing solution collecting means for collecting the fixing solution reliquefied by the defoaming means.

  According to a third aspect of the present invention, in the configuration of the fixing device according to the first or second aspect, the defoaming means includes a roller-shaped defoaming member that rotates while being in contact with the application member. Defoaming is achieved by sandwiching and crushing the foam-like fixing liquid remaining on the coating member between the foam member and the coating member.

  According to a fourth aspect of the present invention, in the fixing device according to the third aspect, a spiral groove is formed on the surface of the defoaming member.

  According to a fifth aspect of the present invention, in the configuration of the fixing device according to the first or second aspect, the defoaming means comprises a blade-shaped defoaming member that contacts the application member, Defoaming is achieved by sandwiching and crushing the foam-like fixing liquid remaining on the coating member between the contact portion with the coating member and the coating member.

  According to a sixth aspect of the invention, in the configuration of the fixing device according to the fifth aspect of the invention, the defoaming member is arranged to be inclined from a horizontal position.

  According to a seventh aspect of the present invention, there is provided the fixing device according to any one of the third to sixth aspects, wherein the fixing liquid recovery means is provided near the end of the defoaming member. It is characterized by comprising a sponge member.

  According to an eighth aspect of the present invention, in addition to the configuration of the fixing device according to any one of the first to seventh aspects, a fine particle collecting unit that collects the fine particles attached to the pressure member is provided. Features.

  According to a ninth aspect of the present invention, in the configuration of the fixing device according to the eighth aspect of the invention, the fine particle collecting means is bonded to the fine particles as compared with the pressure member rotating while being in contact with the pressure member. It consists of a roller-like member having a strong surface.

  A tenth aspect of the present invention is the fixing device according to any one of the first to ninth aspects, wherein at least one of the coating member and the pressure member has elasticity. It is characterized by being.

  According to an eleventh aspect of the present invention, in the configuration of the fixing device according to any one of the first to ninth aspects, at least one of the application member and the pressure member is a belt-shaped member. It is characterized by.

  The invention according to claim 12 provides an image forming apparatus, wherein the image forming apparatus fixes a toner image formed on the medium onto the medium. A fixing device according to any one of claims 1 to 11 that performs processing is provided. The fixing solution used in the fixing device includes a softening agent that dissolves or swells at least a part of the resin contained in the toner, water, a foaming agent composed of a fatty acid salt, and a fatty acid alkanolamide (1: 1) What contains a mold is desirable.

The foam-like fixer having a small bulk (bulk) density remaining on the coating member is re-liquefied by the defoaming means and the volume is reduced from tens of times to one hundredth. It is possible to prevent adverse effects due to the residual foam-like fixing solution (claim 1).
By recovering the fixing liquid reliquefied by the defoaming means by the fixing liquid recovery means, it is possible to more reliably prevent the adverse effect due to the residual foam-like fixing liquid on the coating member (claim 2).
The defoaming means can have a simple structure made of a roller-shaped or blade-shaped defoaming member (claims 3 and 5). By forming a spiral groove on the surface of the roller-shaped defoaming member (Claim 4), or by arranging the blade-shaped defoaming member inclined from the horizontal position (Claim 6), the reliquefied fixing solution is It becomes easy to move to one end side of the defoaming member (in a direction orthogonal to the moving direction of the medium). As a result, the reliquefied fixing solution is less likely to stay in the region related to the fixing operation of the coating member, and the reliquefied fixing solution is efficiently guided to the liquid absorbing sponge member provided near the end of the defoaming member (Claim 7). Can be absorbed.
Fine particles such as toner adhering to the application member are likely to adhere to the pressure member side when the application member and the pressure member are in direct contact. If the amount of fine particles such as toner adhering to the pressure member increases, it may cause so-called back contamination of a medium such as recording paper, but there is a fine particle collecting means for collecting fine particles such as toner adhering to the pressure member. For this reason (claim 8), it is possible to prevent the backside contamination of a medium such as paper due to a large amount of fine particles adhering to the pressure member. Further, since the fine particles adhering to the application member are collected by the fine particle collecting means via the pressure member, the fine particles are not accumulated on the application member on the side in contact with the fine particles. In the case of a fixing device used in an image forming apparatus, if toner accumulates on the coating member, it causes stains on the fixed image, but such image stains can be prevented.
The fine particle collecting means can have a simple structure comprising a roller-like member.
By using at least one of the application member and the pressure member as a roller-like member or a belt-like member having elasticity (claims 10 and 11), it is easily long without excessively increasing the pressure applied to the medium. A nip width (described later) can be ensured, which is advantageous for increasing the conveyance speed and fixing speed of the medium.

[Foam-type fixing solution and its production means]
In the present invention, the fixer is not used as it is, but a foam-like fixer is used. As schematically shown in FIG. 1, the foam-like fixing solution contains a large number of bubbles, and the bubble wall or boundary (plateau boundary) of these bubbles is constituted by the fixing solution. First, a means for generating such a foam-like fixing liquid will be described. In the following description, the “bulk (bulk) density” of the foam-like fixing solution is a mass with respect to a certain volume of the foam-like fixing solution.

  In general, a large bubble of about 0.5 mm to 1 mm can be generated relatively easily by simply stirring the fixing solution, and the generation takes only 1 second or less (for example, 0.1 seconds). Does not take) The present inventors pay attention to the point that bubbles can be easily and quickly generated if they are larger than the desired bubble diameter (bubbles of a size that can be visually observed), and quickly from about 5 μm to 50 μm from large bubbles. The method of generating fine bubbles was studied. As a result, it was confirmed that the method for separating bubbles by applying shear force to the generated large bubbles can produce the desired fine bubbles very quickly compared to the method of directly generating fine bubbles from the liquid state. did.

  An example of means for generating a foam-like fixing solution by such a method is shown in FIG. In this example, the liquid fixing liquid in the fixing liquid container 1 is supplied to the gas / liquid mixing unit 4 through the liquid conveying pipe 3 by the conveying pump 2. The gas / liquid mixing unit 4 is provided with an air port 5 and a microporous sheet 6. In the gas / liquid mixing unit 4, a negative pressure is generated in the air port 5 together with the flow of the liquid supplied through the liquid transport pipe 3, air is introduced into the inside from the air port 5, and the liquid and the gas are mixed. By passing through the microporous sheet 6, large bubbles having a uniform bubble diameter are generated. The hole diameter of the microporous sheet 6 is desirably about 30 μm to 100 μm. The microporous sheet 6 may be a porous member having a continuous foam structure, and a sintered ceramic plate, a nonwoven fabric, a foamed resin sheet, or the like having a pore diameter of about 30 μm to 100 μm can be used.

  Note that the means for generating large bubbles of the fixing solution is not limited to this example. For example, the liquid fixing liquid supplied from the transport pump 2 and the air from the air port 5 are stirred with a blade-like stirrer, and a large bubble is generated while entraining bubbles in the liquid, or supplied from the transport pump 2. It is also possible to adopt a configuration in which large bubbles are generated by bubbling the liquid fixing solution with an air supply pump or the like.

  In order to divide a large bubble of the fixing solution into two or more bubbles, it is effective to apply a shearing force to the large bubble. In the example of FIG. 2, a closed double cylinder is used as a means for separating large bubbles. The outer cylinder 7 is fixed and the inner cylinder 8 is rotatable. The large foam-like fixing solution supplied from a part of the outer cylinder 7 receives a shearing force by the rotation of the inner cylinder 8 while passing through the gap between the inner cylinder 8 and the outer cylinder 7 (this is a flow path). Large bubbles change into fine bubbles, and a foam-like fixing liquid having a desired fine bubble diameter is discharged from an outlet provided in the outer cylinder 7.

The liquid conveyance speed in the double cylinder is determined by the rotational speed of the inner cylinder 8 and the length of the cylinder. When the inner diameter of the outer cylinder 7 is d1 (mm), the length of the outer cylinder 7 is L (mm), the outer diameter of the inner cylinder 8 is d2 (mm), and the rotational speed of the inner cylinder 8 is R (rpm), The liquid conveyance speed V (mm ³ / sec) for generating a simple bubble is
V = L × π × (d1 ² −d2 ² ) / 4 / (1000 / R)
I found out that

For example, when d1 = 10 mm, d2 = 8 mm, L = 50 mm, and rotation speed R = 1000 rpm, the liquid transport speed V is about 1400 mm ³ / sec (1.4 cc / sec). Assuming that 3 cc of the foam-type fixing solution necessary for fixing the toner on the A4 paper is 2 s, it takes only 2 seconds to generate the required amount of the foam-type fixing solution from the liquid fixing solution. A foam-like fixer having a diameter can be generated.

  Thus, as shown in the example of FIG. 2, by combining the mechanism for changing the liquid fixing liquid into a liquid having a large bubble diameter and the mechanism for applying a shearing force to the large bubbles, the liquid fixing liquid can be obtained in a very short time. From 5 μm to 50 μm, a foam-like fixer having a fine bubble diameter can be generated. In addition, in the example of FIG. 2, you may make it improve the liquid conveyance property in a cylinder by providing a helical groove | channel on the surface of the inner cylinder 8. FIG.

  Examples of the transport pump 2 include a gear pump and a bellows pump, and a tube pump is preferable. When there is a mechanism that vibrates or rotates in the fixing liquid, such as a gear pump, the liquid bubbles in the pump, and the liquid may be compressible to reduce the conveying ability. On the other hand, the tube pump is a mechanism that pushes out the liquid in the tube while deforming the tube. Therefore, the only member in contact with the fixing liquid is the tube, and a member that has liquid resistance to the fixing liquid is used. There is no liquid contamination or deterioration of pump system parts. In addition, since the tube is only deformed, the liquid does not foam, and the conveyance capacity can be prevented from being lowered.

As the bulk (bulk) density of the foam-like fixing ^{agent, 0.01g / cm 3 ~0.1g / cm} 3 in the range of about desirable. Further, the fixer is only required to be in the form of foam when it is applied to the layer of resin-containing fine particles such as toner on a recording medium such as paper, and need not be in the form of a foam in the storage container. In the storage container, it is a liquid that does not contain air bubbles, and it is desirable to provide a means for forming the foam in the liquid conveyance path until the liquid is supplied from the container or applied to the resin-containing fine particle layer. This is because the storage container is liquid, and the configuration in which the liquid is taken out from the container to form a foam has a great advantage that the container can be downsized.

[Fixing solution applying means]
In the present invention, the foam-like fixing liquid generated by the means illustrated in FIG. 2 is not directly applied to unfixed toner on paper, for example. The present invention includes a roller- or belt-shaped application member and a pressure member that presses a medium such as paper against the application member, and the film of the foam-like fixer formed on the application member is placed on the medium such as paper. A fixing solution applying means configured to contact and pressurize a resin-containing resin layer such as an unfixed toner is used.

  An example of such fixing solution applying means is schematically shown in FIG. In this example, the application roller 11 is used as the application member, and the pressure roller 13 is used as the pressure member. When the paper to which the unfixed toner is adhered passes between the application roller 11 and the pressure roller 13, the foam-like fixing liquid film on the application roller 11 is contacted and pressed against the unfixed toner layer, thereby unfixing. In this configuration, toner is fixed on paper. In this example, the foam-like fixer generated by the foam-like fixer generating unit shown in FIG. 2 is supplied between the application roller 11 and the film thickness control blade 14 from the supply port 9, and the application roller 11 rotates. As a result, the foam-like fixing liquid adhering to the coating roller 11 passes through the film thickness control blade 14, whereby a foam-shaped fixing liquid film having a desired film thickness is formed on the coating roller 11. It is desirable to optimize the film thickness in accordance with the size of bubbles in the foam-like fixing liquid, the pressure applied by the pressure roller 13, the thickness of the unfixed toner layer, the environmental temperature, and the like. FIG. 4 schematically shows how the foam-like fixing liquid on the application roller is applied to the toner layer.

  FIG. 5 is an explanatory diagram of the film thickness control of the foam-like fixing liquid film on the application roller 11. When the film thickness is reduced, the gap between the film thickness control blade 14 and the application roller 11 is narrowed as shown in FIG. 5A, and when the film thickness is increased, the gap as shown in FIG. 5B. To widen. Such a gap control can be performed by changing the angle of the rotating shaft 15 to which one end of the film thickness control blade 14 is attached by a motor or the like (not shown).

  In the example of FIG. 3, the film thickness control blade is used to control the film thickness of the foam-like fixing liquid film on the application roller 11, but the present invention is not limited to this. For example, a wire bar is stretched close to the coating roller 11 in the axial direction of the roller, a foam-like fixing solution is dropped between the wire bar and the coating roller 11, and the foam bar is adjusted by adjusting the distance between the wire bar and the coating roller 11. The film thickness of the fixer film may be controlled. According to the configuration using such a wire bar, it is possible to improve the uniformity of the film thickness of the foam-like fixing liquid in the coating roller axial direction as compared with the configuration using a blade.

  Now, when the fixing solution applying means as described above is used, there is a problem that toner adheres to the coating roller side if the fixing speed is increased too much, and the present inventors have analyzed the mechanism. The following is an explanation based on the analysis result.

  FIG. 6 shows models with and without toner adhering to the application roller (application member). The application roller has liquid repellency and the paper has lyophilicity.

  FIG. 6A shows a case where the application roller is peeled at a timing after the liquid fixing solution on the application roller contacts the toner layer and penetrates the toner layer and reaches the paper. A coupling force is generated between the toner, between the toner and the paper, and between the toner and the coating roller due to the surface tension of the liquid, but the coating roller is liquid repellent and the paper is lyophilic. The binding force with the paper is excellent, and the toner does not adhere to the application roller when the application roller is peeled off.

  FIG. 6B shows a state where the liquid fixing liquid on the application roller contacts the toner layer and the application roller is peeled off at a timing at which the fixing liquid does not reach the paper through the toner layer (a timing at which the toner layer penetrates partway through the toner layer). Shows the case. Bonding force due to the surface tension of the liquid is generated between the toner infiltrated with the fixer and between the toner infiltrated with the fixer and the coating roller, but the bonding force between the dry toner is weak, so when the coating roller is peeled off The toner layer peels off at the dry portion, and the toner infiltrated with the fixing solution adheres to the application roller.

  From this model, it can be seen that in order to prevent significant toner adhesion to the application roller, the contact portion nip time of the application roller with the paper is determined so that the fixing solution that has contacted the toner layer penetrates the toner layer. It is necessary to make it longer than the time to reach the paper.

  The “nip” refers to a portion between the contact start point of the application roller (application member) with the paper (medium) and the start point of peeling. Therefore, the “nip time” is the time from the start of contact to the start of peeling. Further, the “nip width” indicates the length in the conveyance direction of the paper (medium) between the contact start point and the peeling start point. The “nip pressure” is a pressure applied to the nip portion, and indicates a value obtained by dividing the load on the nip portion by the area of the nip portion.

  By the way, the present inventors observed the state in which the foam-like fixing solution permeates the resin-containing fine particle layer in an optical microscope in a large scale model experiment using 300 μm zirconia beads. As a result, as shown in FIG. 7, the foam-like fixing solution penetrates through the gaps between the zirconia beads without breaking the bubbles, and the bubbles in contact with the zirconia beads pressurize the gaps between the beads while the bubbles on the upper side pressurize the bubbles. It was found that bubbles penetrated. In general, in the case of a liquid, the permeation force between fine particles is permeation utilizing capillary action due to the surface tension of the liquid. However, as a result of observation, in the case of bubbles, the bubbles behave like a flexible continuum, and the bubbles continuously fill the gaps between the fine particles while the upper bubbles push the bubbles that have penetrated between the fine particles. It was found for the first time that it was different from the conventional liquid permeation principle. Although it was not actually observed, even in a 6 μm sized fine particle layer such as toner, as in the case of the large scale model experiment, the bubble that penetrated between the fine particles was continuously pressed while the foam on the top pushed. It can be estimated that it penetrates. Further, in the large scale model experiment, when the thickness of the foam-like fixing liquid film is smaller than the thickness of the fine particle layer, as shown in FIG. It was also observed that it could not be reached quickly.

  From the above experiments, in the actual scale, the thickness of the foam-like fixing solution film on the application roller and the thickness of the toner (resin-containing fine particle) layer on the paper (medium) It was found that there was a close correlation with the penetration time of the (fine particle) layer.

  We have devised a unique method to measure the time (defined as penetration time) until the foam-like fixer penetrates the resin-containing fine particle layer such as toner and reaches a medium such as paper. Time was measured.

FIG. 9 is an explanatory diagram of an example of a measuring apparatus based on the devised penetration time measuring method. Toner was used as the resin-containing fine particles. Since the fixing solution contains an ionic material, for example, a foaming agent and a dispersing agent necessary for foaming, it exhibits a resistance value of 10 ⁷ Ω · cm or less and has conductivity. Therefore, the upper electrode is viewed as an application member and the lower electrode as a medium, a foam-like fixing liquid film is formed on the lower surface of the upper electrode, and a toner layer is formed on the upper surface of the lower electrode. Then, a load detection load cell is disposed under the lower electrode, and a voltage is applied between the upper and lower electrodes. When a weight is placed on the upper electrode and the upper electrode is brought into contact with the lower electrode, the load detection load cell detects the load on the upper electrode. Thereafter, when the foam-like fixing liquid passes through the toner layer and reaches the lower electrode, a current flows between the upper and lower electrodes, so that the voltage value between the upper and lower electrodes changes. Then, the time from when the load is detected by the load detection load cell to when the voltage change between the upper and lower electrodes is detected is measured as the toner layer penetration time. A measurement example is shown below.

(Measurement Example 1)
A foam-like fixing liquid film having an average bubble diameter of 20 μm and a bulk (bulk) density of 0.05 g / cm ³ is formed on the upper electrode, and a spherical toner layer having an average particle diameter of 6 μm is formed on the lower electrode with a thickness of 30 μm. It was measured by changing the thickness of the fixer film. SUS304 was used as the material for the upper and lower electrodes. The upper electrode was fixed to the linear stage, and was brought into contact with the lower electrode at a pressure of 0.03 kgf / cm ² (pressure during application). In order to prevent the electrolysis of the fixing solution between the upper and lower electrodes, the voltage applied between the upper and lower electrodes was set to 0.8V. The measurement results are shown in FIG. In FIG. 10, the horizontal axis represents the thickness (μm) of the foam-like fixing liquid film, and the vertical axis represents the toner layer penetration time (ms).
As shown in FIG. 10, when the thickness of the foam-like fixing liquid film is equal to or larger than the toner layer thickness, the penetration time is almost constant, but the thickness of the foam-like fixing liquid film is thinner than the toner layer thickness. In some cases, the thinner the film, the longer the penetration time. This confirms that the bubbles permeate the gaps in the toner layer while the bubbles in the upper part continuously pushes the bubbles in the gaps of the toner layer to the thickness of the bubbles, as described with reference to FIGS. Is.

(Measurement example 2)
A 50 μm thick film of a foam-like fixing solution having an average bubble diameter of 20 μm and a bulk density of 0.05 g / cm ³ was formed on the upper electrode, and a spherical toner layer having an average particle diameter of 6 μm was formed on the lower electrode. SUS304 was used as the material for the upper and lower electrodes. The upper electrode was fixed on a linear stage, and the lower electrode was brought into contact with the lower electrode at different pressures (application pressures), and the toner layer penetration time at each application pressure was measured. In order to prevent electrolysis of the fixing solution between the electrodes, the applied voltage between the upper and lower electrodes was set to 0.8V. The measurement results are shown in FIG. The horizontal axis represents the application pressure, and the vertical axis represents the toner layer penetration time. As can be seen from FIG. 11, the higher the application pressure, the shorter the toner layer permeation time. When bubbles penetrate into the gap between the toner layers and the upper bubbles are continuously pressed, the permeation speed increases as the pressing force increases. Supports faster and shorter penetration times.

(Measurement Example 3)
The difference in penetration time of the toner layer due to the difference in foam viscosity of the foam-like fixing solution was measured. A 50 μm thick film of a foam-like fixing solution having an average bubble diameter of 20 μm and a bulk density of 0.05 g / cm ³ was formed on the upper electrode, and a spherical toner layer having an average particle diameter of 6 μm was formed on the lower electrode. SUS304 was used as the material for the upper and lower electrodes. The upper electrode was fixed to the linear stage, and was brought into contact with the lower electrode at a pressure of 0.03 kgf / cm ² . In order to prevent electrolysis of the fixing solution between the electrodes, the applied voltage between the upper and lower electrodes was set to 0.8V.
The measurement results are shown in FIG. The horizontal axis represents the foam viscosity of the foam-like fixing solution, and the vertical axis represents the toner layer penetration time. For the foam viscosity, a cone plate type rotational viscometer is used, the outer diameter of the rotor is 60 mm, the cone angle is 1 degree, the gap between the cone part and the plate part is 3 mm, and the rotation speed is 10 (1 / s) (10 rotations). The measured value of rotational viscosity 10 seconds after the start of rotation at 25 ° C. was defined as the foam viscosity. As shown in FIG. 12, the smaller the bubble viscosity, the shorter the toner layer penetration time. This is because when the bubbles penetrate into the gap between the toner layers and the upper bubbles are continuously pressed, the penetration speed increases as the bubbles are softer. This confirms that time will be shortened.

  Up to now, there has been no example of analyzing the permeation behavior of a foam-like liquid having fine bubbles into a fine particle layer, and the present inventors have revealed the behavior for the first time as in the above measurement example.

  From FIG. 6 and the series of analyzes described above, in order to prevent the resin-containing fine particles from adhering to a coating member such as a coating funnel for applying the foam-like fixing solution to the resin-containing fine particles such as toner, The nip time at the contact portion with the medium needs to be set to be equal to or longer than the resin-containing fine particle layer permeation passage time until the foam-like fixing solution reaches the medium. From the above measurement example, when the resin-containing fine particles are toner of about 5 μm, the permeation time is approximately in the range of 50 to 300 milliseconds under various foam-like fixing solutions and application conditions. Therefore, the contact nip time of the coating member with a recording medium such as paper must be at least in the range of 50 milliseconds to 300 milliseconds.

  There are two problems to be solved in the fixing device as schematically shown in FIG. One is processing (A) of the foam-like fixing liquid remaining on the application roller without being attached to the toner, and the other is processing (B) of toner adhering to the pressure roller side.

  Regarding the problem (A), since the foam-like fixing solution is bulky, even if a few percent of the foam-like fixing solution remains without being applied to the toner, the volume immediately becomes a large volume. It is necessary to remove it quickly from above the application roller. In the present invention, as shown in the following embodiments, the foam-like fixing liquid remaining on the coating roller is defoamed and reliquefied, thereby significantly reducing its volume and avoiding substantial problems.

  Regarding issue (B). Although the amount of toner adhering to each fixing process is very small, an electrophotographic process or the like that normally passes tens of thousands of sheets cannot be overlooked. In the present invention, as shown in the following embodiment, the problem is solved by fixing and holding the toner adhering to the pressure roller on the collecting member during the process.

  Hereinafter, some embodiments of the fixing device according to the present invention will be described in detail. In any of the embodiments, the resin-containing fine particles to be fixed are toner, and the medium on which the toner is fixed is paper (recording medium), but is not limited thereto. The nip time is in the range of 50 milliseconds to 300 milliseconds.

[First Embodiment of Fixing Device]
FIG. 13A is a schematic configuration diagram of the fixing device according to the first embodiment. The fixing liquid applying unit in the present embodiment includes an application roller 20 as an application member, a pressure roller 21 opposed thereto, and a film thickness control blade 22. The fixing device further includes a defoaming roller 23 serving as a defoaming unit and a cleaning roller 24 serving as a unit that collects toner adhering to the pressure roller 21.

  The paper 25 to which the unfixed toner 26 is attached is conveyed from the right side to the left side in the drawing, and the unfixed toner 26 is fixed to the paper 25 when passing between the application roller 20 and the pressure roller 21 while being pressurized. It is done. The means described with reference to FIG. 2 is used as the means for generating the foam-like fixing solution, but is not limited thereto. The foam-like fixing solution is dropped between the application roller 20 and the film thickness control blade 22 from the supply port 9, and a film of the foam-like fixing solution having a required thickness is formed on the application roller 20. Even after the foam-like fixing liquid film is contact-pressed to the unfixed toner 26, a small amount of the foam-like fixing liquid remains on the coating roller. This residual foam-like fixer is crushed between the defoaming roller 23 and the coating roller 20 to defoam and re-liquefy.

The nip time of the coating roller 20 is
Nip time = nip width / paper transport speed. The transport speed of the paper 25 can be obtained from design data of a paper transport drive mechanism (not shown). The nip width is obtained by thinly applying a non-drying colored paint on the entire surface of the application roller 20, pressing the paper between the application roller 20 and the pressure roller 21 (each roller is not rotated), and attaching the color paint to the paper. The length of the colored portion (usually colored in a rectangular shape) in the paper conveyance direction can be measured as the nip width.

  By adjusting the nip width according to the paper conveyance speed, it is necessary to make the nip time equal to or longer than the toner layer penetration time of the foam-like fixer. In the example of FIG. 13A, since the pressure roller 21 is an elastic porous body (hereinafter referred to as sponge) roller, the distance between the axes of the application roller 20 and the pressure roller 21 according to the paper conveyance speed. Can be easily changed to change the nip width. Elastic rubber is also suitable as the material of the pressure roller 21, but since the sponge can be deformed with a weaker force than the elastic rubber, the pressure applied to the application roller 20 can be increased by using the pressure roller 21 as a sponge roller. There is an advantage that a long nip width can be secured without being excessively high.

  The fixing solution contains a softener or swelling agent for the toner resin. If the fixing solution adheres to the sponge pressure roller 21, problems such as softening of the sponge material may occur. . In order to prevent this, it is desirable to use a material that does not soften or swell the softener or swelling agent as the resin material of the sponge material. Moreover, it is good also as a structure which covered the surface of the pressure roller 21 with the flexible film. Even if the sponge material is a material that deteriorates with the softener or swelling agent, the deterioration of the pressure roller 21 is prevented by covering with a flexible film that does not soften or swell with the softener or swelling agent. Can do. As the sponge material for the pressure roller 21, for example, a porous body of resin such as polyethylene, polypropylene, and polyamide is suitable. Examples of the flexible film that covers the surface of the pressure roller 21 include polyethylene terephthalate, polyethylene, polypropylene, ethylene tetrafluoride / fluoroalkyl vinyl ether copolymer (PFA), and perfluoroethylene propene copolymer (PFEP). Film is suitable.

  13A, when the application roller 20 and the pressure roller 21 are always in contact with each other, the foam-like fixing liquid on the application roller 20 adheres to the pressure roller 21 when the paper 25 is not conveyed. There is a risk of fouling. In order to prevent this, a means (not shown) for detecting the leading edge of the paper is provided at the right position of the application roller 20, and the fixing solution is applied only from the leading edge of the paper to the rear in accordance with a paper leading edge detection signal by this means. It is desirable to form a foam-like fixing liquid film on the application roller 20 at such timing.

  As can be seen from the measurement results in FIG. 11, the higher the nip pressure (= nip portion load / nip portion area) at the coating nip portion, the shorter the toner layer penetration time. Therefore, the higher the nip pressure at the coating nip portion, the higher the image. The nip time in a range where deterioration does not occur can be shortened, and if the nip width is the same, the paper conveyance speed can be increased, and higher-speed fixing is possible.

  Further, from the measurement results of FIG. 12, the permeation time varies depending on the foam viscosity of the foam-like fixing solution. However, if the nip time and the nip pressure are constant, for example, the fixing solution prescription is changed or the operating environment temperature is lowered. When the bubble viscosity is increased, the toner layer permeation time is longer than the nip time, which may cause image deterioration. In order to prevent this, it is possible to adjust the nip time to be the same as or longer than the toner layer penetration time according to the foam viscosity of the foam-like fixer by using the change in the toner layer penetration time due to the nip pressure. desirable.

  Here, since the foam viscosity of the foam-like fixing liquid is the rotational viscosity in the cone-plate type rotational viscometer as described above, the means for detecting the foam viscosity of the foam-like fixing liquid in the fixing device is a cone-plate type rotational viscometer. It is desirable to use means close to the measurement principle. For example, a rotor is provided in the flow path pipe in front of the foam-like fixing liquid supply port 9, a motor torque applied to the rotor is detected, and this is regarded as a foam viscosity as a substitute value of the rotational viscosity, A configuration in which a cantilever type vibrator is provided instead of the rotor, a change in its natural frequency is detected, and this is regarded as a bubble viscosity as a substitute value of the rotational viscosity is desirable.

  As the nip pressure adjusting means, a mechanism capable of changing the distance between the axes of the application roller 20 and the pressure roller 21 is provided, and the distance between the axes of the application roller 20 and the pressure roller 21 is adjusted according to the bubble viscosity detection signal. Is desirable.

  Next, in order to shorten the penetration time of the toner layer, the thickness of the foam-like fixing liquid film on the application roller 20 needs to be equal to or greater than the thickness of the toner layer (this is the case where the toner is other resin-containing fine particles). Is the same). When this fixing device is used in a color image forming apparatus, the thickness of the toner layer on the paper varies depending on the color or brightness of the image to be formed. Therefore, the film thickness of the foam-like fixing liquid film is set based on the maximum value of the thickness of the toner layer adhering to the paper. Since the maximum value of the thickness of the toner layer can be obtained from the image signal, for example, the gap of the film thickness control blade 22 is controlled according to the image signal (see FIG. 5), and the foam-like fixing liquid on the application roller 20 It is preferable to adjust the thickness of the film to be equal to or greater than the maximum thickness of the toner layer. In the image apparatus, the thickness of the toner layer adhering to the paper is fixedly determined by a value calculated based on a setting table in accordance with an image signal from a scanner or a PC. Therefore, based on the image signal, the film thickness of the foam-like fixing solution on the application roller can be adjusted to be equal to or larger than the maximum value of the set value of the thickness of the toner layer deposited on the paper.

  When the toner layer has a different thickness, the toner layer permeation time differs (the thicker the toner layer, the longer the permeation time). Therefore, depending on the thickness of the toner layer, the nip at the contact portion nip between the coating roller 20 and the paper 25 The time needs to be variable. As means for changing the nip time, means for changing the paper conveyance speed and means for changing the nip width are suitable. For example, the maximum value of the toner layer thickness on the paper is calculated from the image signal, this toner layer thickness is converted into the penetration time, and the nip width and paper transport speed are changed so that the nip time is equal to or greater than the penetration time. You can do it.

  In the present embodiment, a defoaming roller 23 that rotates while contacting the application roller 20 is provided. The foam-like fixing liquid remaining on the application roller 20 without being attached to the toner layer is crushed and defoamed by the defoaming roller 23 and the application roller 20, as shown in an enlarged view in FIG. Reliquefied. Since the volume (bulk) density of the foam-like fixing solution is small, the volume of the re-liquefied fixing solution is extremely small. Therefore, unlike the case where the remaining foam-like fixing solution is left as it is, other members are contaminated with the fixing solution. Such inconvenience is avoided.

  FIG. 14 is a view of the antifoam roller viewed from the direction of arrow A in FIG. In the present embodiment, as shown in FIG. 14, a very shallow spiral groove 27 is formed on the surface of the defoaming roller 23. Further, the defoaming roller 23 is subjected to fluororesin processing so as to repel the re-liquefied fixing solution. The re-liquefied fixing solution is guided to the spiral groove 27 as the defoaming roller 23 rotates, is guided to the end of the defoaming roller 23, and is applied to a circular liquid absorbing sponge 28 fixed to the end of the application roller 20. To be recovered. That is, the liquid absorbing sponge is a means for collecting the defoamed and reliquefied fixing solution. As the liquid absorbing sponge 28, a material made of nylon, cellulose or the like that is not affected by the fixing liquid is used. By providing the recovery means for the re-liquefied fixing solution in this way, contamination of other members by the foam-like fixing solution remaining on the coating roller can be prevented more reliably.

  In addition, when the linear speed of the defoaming roller 23 is high, the reliquefied fixing solution tends to wrap around the front side of the defoaming roller 23. In order to prevent such re-liquefied fixing solution from wrapping around, a cover 29 may be provided close to the defoaming roller 23 as shown in FIG.

  Further, in place of the defoaming roller, as shown in FIG. 16, an antifoaming blade 30 is provided, and the residual foam-like fixing liquid is sandwiched between the defoaming blade 30 and the coating roller 20 to defoam and re-liquefy. You may make it do. In this case, as shown in FIG. 17, it is preferable that the defoaming blade 30 is tilted from the horizontal to facilitate the flow of the reliquefied fixing liquid to the liquid absorbing sponge 28 by gravity. FIG. 17 is a view of the defoaming blade 30 viewed from the direction of arrow B in FIG. As the material of the defoaming blade 30, EPDM (ethylene-propylene-diene rubber), silicone-modified rubber or the like can be used.

  In the present embodiment, a cleaning roller 24 that rotates while being in contact with the pressure roller 21 is provided as means for collecting the toner adhering to the pressure roller 21. A small amount of toner may adhere to the surface of the application roller 20. In some cases, the toner adhering to the application roller 20 may adhere to the pressure roller 21 between the paper passes or during the preliminary rotation of the application roller 20. Since the toner adhering to the pressure roller 21 is not preferable because the amount of the toner increases as it causes stains on the back of the paper, the toner is adhered and fixed to the cleaning roller 24 side. The surface of the pressure roller 21 is covered with a film made of a material that does not easily adhere to toner, and at least the surface material of the cleaning roller 24 is made of metal, ceramics, or the like that has strong adhesiveness to the toner. The toner adhering to is trapped on the surface of the cleaning roller 24 (see FIG. 13C). Since the toner adheres to the surface of the cleaning roller 24 more easily when the toner adheres, the toner is fixed on the cleaning roller 24 and does not return to the pressure roller 21.

[Other Embodiments of Fixing Device]
18, the application roller and the pressure roller may be replaced with an endless application belt 31 and a pressure belt 24, respectively, or only the application roller may be replaced with an endless application belt 31 as shown in FIG. Further, as shown in FIG. 20, only the pressure roller may be replaced with an endless pressure belt 33. As the coating belt 31 in the configuration shown in FIG. 18 or 19, for example, a seamless nickel belt, a seamless PET file, or a belt member in which a base such as polyimide is coated with a releasable fluororesin such as PFA can be used.

  In the configuration shown in FIG. 18 or FIG. 19, the film thickness control blade 22 is disposed at a portion facing the roller 34 in the three rollers on which the coating belt is stretched, and the defoaming roller 23 is the roller 35. It arrange | positions so that an application | coating belt may be contacted in a site | part. The structure of the defoaming roller 23 may be the same as that of the first embodiment (see FIG. 14). A liquid absorbing sponge (see FIG. 14) for collecting the reliquefied fixing liquid guided to the end of the defoaming roller 23 is provided at the end of the roller 35. Note that a defoaming blade may be provided in place of the defoaming roller 23. In this case, the defoaming blade is preferably inclined from the horizontal as shown in FIG. In the case of the configuration shown in FIG. 18 or FIG. 20, the cleaning roller 24 is disposed so as to contact the pressure belt at a portion facing the roller 37 or 38 on which the pressure belt 32 or 33 is stretched. It is desirable that at least the surface of the pressure belt 32 or 33 be made of a material that is difficult for toner to adhere to.

  As shown in FIGS. 18 to 20, the configuration using a belt for at least one of the application member and the pressure member (1) can easily ensure a wide nip width. (2) The force applied to the paper can be suppressed, and the occurrence of paper wrinkles can be easily avoided. (3) If the nip time is the same, there is an advantage that it is possible to increase the paper conveyance speed and to enable high-speed fixing.

[Fixing solution for fixer]
Next, the liquid formulation of the fixing solution will be described. As described above, the foam-like fixing liquid has a configuration in which bubbles are contained in a liquid containing a softening agent. The liquid containing the softening agent preferably contains a foaming agent and a foam-increasing agent in order to stably contain bubbles and form a foam layer that has a bubble size that is as uniform as possible. In addition, it is desirable to contain a thickener since bubbles are more stably dispersed in the liquid when the viscosity is higher to some extent.

  As the foaming agent, an anionic surfactant, particularly a fatty acid salt is desirable. Since the fatty acid salt has surface activity, the surface tension of the fixer containing water is lowered to make the fixer easier to foam, and the fatty acid salt has a layered lamellar structure on the surface of the foam, so the foam wall (plateau boundary) is another It is stronger than the surfactants and the foam stability is extremely high. Further, in order to make the foaming property of the fatty acid salt effective, it is desirable that the fixing solution contains water. As the fatty acid, a saturated fatty acid resistant to oxidation is desirable from the viewpoint of long-term stability in the air. However, the presence of some unsaturated fatty acid salt in the fixing solution containing saturated fatty acid salt helps to dissolve and disperse the fatty acid salt in water and has excellent foaming properties at low temperatures from 5 ° C to 15 ° C. Can be stably fixed in a wide environmental temperature range, and can prevent separation of fatty acid salts when the fixing solution is left for a long period of time.

  As the fatty acid used in the saturated fatty acid salt, saturated fatty acids having 12, 14, 16, and 18 carbon atoms, specifically lauric acid, myristic acid, palmitic acid, and stearic acid are suitable. A saturated fatty acid salt having 11 or less carbon atoms has a large odor and is not suitable as a fixing solution for use in image forming equipment used in offices and homes. In addition, saturated fatty acid salts having 19 or more carbon atoms are less soluble in water and significantly lower the stability of the fixing solution. Saturated fatty acid salts with these saturated fatty acids are used alone or in combination as a foaming agent.

  Further, an unsaturated fatty acid salt may be used, and an unsaturated fatty acid having 18 carbon atoms and 1 to 3 double bonds is desirable. Specifically, oleic acid, linoleic acid, and linolenic acid are suitable. Since the reactivity is strong when the double bond is 4 or more, the stability of the fixing solution is poor. These unsaturated fatty acid salts with unsaturated saturated fatty acids are used alone or in combination as a foaming agent. Moreover, you may mix and use the said saturated fatty acid salt and unsaturated fatty acid salt as a foaming agent.

  Further, in the saturated fatty acid salt or unsaturated fatty acid salt, when used as a foaming agent for the fixing solution, a sodium salt, potassium salt or amine salt is desirable. In a fixing device, it is an important factor to make it possible to quickly fix after turning on the power. In order to be able to fix in the fixing device, it is essential that the fixing solution is in an appropriate foam shape. It is possible to create a fixable state. In particular, by using an amine salt, foaming can be generated in the shortest time when a shearing force is applied to the fixing solution, and a foam-like fixing solution can be easily generated. It can be made possible.

  The softening agent that is softened by dissolving or swelling the resin contains an aliphatic ester. This aliphatic ester is excellent in solubility or swelling property that dissolves or swells at least a part of the resin contained in the toner or the like. The softening agent has an acute oral toxicity LD50 of more than 3 g / kg, more preferably 5 g / kg, from the viewpoint of safety to the human body. As aliphatic esters are frequently used as cosmetic raw materials, they are highly safe for the human body.

  Further, the fixing of the toner to the recording medium such as paper is performed by an apparatus frequently used in a sealed environment, and the softening agent remains in the toner even after the fixing of the toner to the recording medium. It is preferable that the fixing of the toner is not accompanied by generation of a volatile organic compound (VOC) and an unpleasant odor. That is, the softener preferably does not contain volatile organic compounds (VOC) and substances that cause unpleasant odors. Aliphatic esters have a high boiling point and low volatility and have no irritating odor as compared to generally used organic solvents (toluene, xylene, methyl ethyl ketone, ethyl acetate, etc.).

  In addition, as a practical odor measurement scale that can measure odors in office environments with high accuracy, the odor index (10 × log) by the three-point comparison odor bag method that is sensory measurement The dilution factor of the substance until it disappears)) can be used as an indicator of odor. The odor index of the aliphatic ester contained in the softener is preferably 10 or less. In this case, an unpleasant odor is not felt in a normal office environment. Furthermore, it is preferable that not only the softening agent but also other liquid agents contained in the fixing solution have no unpleasant odor and irritating odor.

  In the fixing solution according to the present invention, preferably, the aliphatic ester includes a saturated aliphatic ester. When the above aliphatic ester contains a saturated aliphatic ester, the storage stability (resistance to oxidation, hydrolysis, etc.) of the softener can be improved. Further, saturated aliphatic esters are highly safe for the human body, and many saturated aliphatic esters can dissolve or swell the resin contained in the toner within 1 second. Furthermore, saturated aliphatic esters can reduce the tackiness of the toner provided on the recording medium. This is considered to be because an oil film is formed on the surface of the toner in which the saturated aliphatic ester is dissolved or swollen.

Therefore, in the fixing solution according to the present invention, preferably, the saturated aliphatic ester has the general formula R1COOR2
The compound represented by these is included. Here, R1 is an alkyl group having 11 to 14 carbon atoms, and R2 is a linear or branched alkyl group having 1 to 6 carbon atoms. If the number of carbon atoms in R1 and R2 is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability is lowered.

  That is, the saturated aliphatic ester includes a compound represented by the general formula R1COOR2, wherein R1 is an alkyl group having 11 to 14 carbon atoms, and R2 is a linear type having 1 to 6 carbon atoms or When the branched alkyl group is used, the solubility or swelling property with respect to the resin contained in the toner can be improved. Moreover, the odor index of said compound is 10 or less, and said compound does not have an unpleasant odor and an irritating odor.

  Examples of the aliphatic monocarboxylic acid ester that is the above compound include ethyl laurate, hexyl laurate, ethyl tridecylate, isopropyl tridecylate, ethyl myristate, isopropyl myristate, and the like. Many of these aliphatic monocarboxylic acid esters, which are the above compounds, are soluble in oily solvents, but not in water. Therefore, for many of the aliphatic monocarboxylic acid esters which are the above-mentioned compounds, in an aqueous solvent, glycols are contained in the fixing solution as a solubilizing agent and are in the form of a solution or a microemulsion.

  In the fixing solution of the present invention, preferably, the aliphatic ester includes an aliphatic dicarboxylic acid ester. When the aliphatic ester includes an aliphatic dicarboxylic acid ester, the resin contained in the toner can be dissolved or swollen in a shorter time. For example, in high-speed printing of about 60 ppm, it is desirable that the time from applying the fixing solution to the unfixed toner on the recording medium to fixing the toner on the recording medium is within 1 second. When the aliphatic ester includes an aliphatic dicarboxylic acid ester, the time from when the fixing solution is applied to the unfixed toner or the like on the recording medium to when the toner is fixed is within 0.1 seconds. It becomes possible. Furthermore, since the resin contained in the toner can be dissolved or swollen by adding a smaller amount of the softening agent, the content of the softening agent contained in the fixing liquid can be reduced.

Therefore, in the fixing solution of the present invention, preferably, the aliphatic dicarboxylic acid ester is represented by the general formula R3 (COOR4) _2.
R3 is an alkylene group having 3 to 8 carbon atoms, and R4 is a linear or branched alkyl group having 3 to 5 carbon atoms. If the number of carbon atoms in R1 and R2 is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability is lowered.

That is, the aliphatic dicarboxylic acid ester includes a compound represented by the general formula R3 (COOR4) ₂ , R3 is an alkylene group having 3 to 8 carbon atoms, and R4 has 3 to 5 carbon atoms. In the case of the linear or branched alkyl group, the solubility or swelling property with respect to the resin contained in the toner can be improved. Moreover, the odor index of said compound is 10 or less, and said compound does not have an unpleasant odor and an irritating odor.

  Examples of the aliphatic dicarboxylic acid ester that is the above compound include diethylhexyl succinate, dibutyl adipate, diisobutyl adipate, diisopropyl adipate, diisodecyl adipate, diethyl sebacate, and dibutyl sebacate. Many of these aliphatic dicarboxylic acid esters, which are the above compounds, are soluble in oily solvents, but not in water. Therefore, in an aqueous solvent, glycols are contained in the fixing solution as a dissolution aid and are in the form of a solution or microemulsion.

  Furthermore, in the fixing solution according to the present invention, the aliphatic ester preferably contains a dialkoxyalkyl aliphatic dicarboxylate. When the above aliphatic ester contains an aliphatic dicarboxylic acid dialkoxyalkyl, the fixing property of the toner to the recording medium can be improved.

In the fixing solution of the present invention, preferably, the above-mentioned aliphatic dicarboxylic acid dialkoxyalkyl is represented by the general formula R5 (COOR6-O-R7) _2.
R5 is an alkylene group having 2 to 8 carbon atoms, R6 is an alkylene group having 2 to 4 carbon atoms, and R7 is an alkyl group having 1 to 4 carbon atoms. It is. If the number of carbon atoms in R1 and R2 is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability is lowered.

That is, the above-mentioned aliphatic dicarboxylic acid dialkoxyalkyl includes a compound represented by the general formula R5 (COOR6-O-R7) ₂ , wherein R5 is an alkylene group having 2 to 8 carbon atoms, and R6 is carbon. When R7 is an alkylene group having 2 or more and 4 or less and R7 is an alkyl group having 1 or more and 4 or less carbon atoms, the solubility or swelling property with respect to the resin contained in the toner can be improved. Moreover, the odor index of said compound is 10 or less, and said compound does not have an unpleasant odor and an irritating odor.

  Examples of the aliphatic dicarboxylate dialkoxyalkyl which is the above compound include diethoxyethyl succinate, dibutoxyethyl succinate, diethoxyethyl adipate, dibutoxyethyl adipate, diethoxyethyl sebacate and the like. . In an aqueous solvent, these aliphatic dicarboxylic acid dialkoxyalkyls are contained in the fixing solution as a solubilizing agent, and dissolved or microemulsified.

  Further, although not fatty acid esters, citrate esters, ethylene carbonate, and propylene carbonate are also suitable as softeners or swelling agents.

  Now, when the foam-like fixer is allowed to permeate into the fine particle layer such as toner and the bubbles break, the penetration is inhibited. Therefore, a foam excellent in foam stability is required. For this reason, it is desirable to contain a fatty acid alkanolamide (1: 1) type in the fixing solution. Fatty acid alkanolamides include (1: 1) type and (1: 2) type, but it was found that (1: 1) type is suitable for foam stability in the present invention.

  The fixing device of the present invention can fix not only toner but also fine particles containing a resin. For example, the present invention can be applied to fixing resin-containing fine particles containing a conductive member. The medium to be fixed is not limited to paper, but may be a medium made of metal, resin, ceramics, or the like. However, it is desirable that the medium has permeability to the fixing solution. When the medium substrate does not have liquid permeability, it is desirable to provide a liquid-permeable layer on the substrate. The form of the medium is not limited to a sheet shape, and may be a three-dimensional medium having a flat surface and a curved surface. For example, the fixing device of the present invention can also be applied to uses such as transparently fixing fine resin particles uniformly on a medium such as paper to protect the paper surface (so-called varnish coating).

  Among the fine particles containing the resin, the toner used in the electrophotographic process has the highest fixing effect in combination with the fixing solution of the present invention. The toner contains a colorant, a charge control agent, and a resin such as a binder resin and a release agent. Although the resin contained in the toner is not particularly limited, examples of suitable binder resins include polystyrene resins, styrene-acrylic copolymer resins, and polyester resins. Moreover, as a mold release agent, wax components, such as a carbanau wax and polyethylene, etc. are mentioned, for example. The toner may contain a known colorant, charge control agent, fluidity-imparting agent, external additive and the like in addition to the binder resin. Further, the toner is preferably subjected to a water repellency treatment by fixing hydrophobic fine particles such as hydrophobic silica having a methyl group and hydrophobic titanium oxide to the surface of the toner particles. Examples of the medium include paper, cloth, and a plastic film such as an OHP sheet having a liquid permeable layer. The oiliness in the present invention means the property that the solubility in water at room temperature (20 ° C.) is 0.1% by weight or less.

  The foam-like fixing solution preferably has sufficient affinity for the water-repellent treated toner particles. Here, affinity means the degree of extended wetting of the liquid with respect to the surface of the solid when the liquid comes into contact with the solid. That is, it is preferable that the foam-like fixing solution exhibits sufficient wettability with respect to the water-repellent treated toner. The surface of the toner subjected to water repellency treatment with hydrophobic fine particles such as hydrophobic silica and hydrophobic titanium oxide is covered with methyl groups present on the surfaces of hydrophobic silica and hydrophobic titanium oxide, and is approximately 20 mN / m. Has a surface energy of a degree. In reality, since the entire surface of the water-repellent treated toner is not completely covered with hydrophobic fine particles, the surface energy of the water-repellent treated toner is estimated to be approximately 20 to 30 mN / m. . Therefore, in order to have affinity for the water-repellent toner (having sufficient wettability), the surface tension of the foam-like fixing liquid is preferably 20 to 30 mN / m.

  In the case of using an aqueous solvent, it is preferable that the surface tension is 20 to 30 mN / m by adding a surfactant. In the case of an aqueous solvent, it is desirable to contain a unit price or a polyhydric alcohol. These materials have the advantage of increasing the stability of the bubbles in the foam-like fixing solution and making it difficult to break the bubbles. For example, monohydric alcohols such as cetanol, and polyhydric alcohols such as glycerin, propylene glycol, and 1,3 butylene glycol are desirable. Further, by containing these unit price or polyhydric alcohols, it is effective in preventing curling of a medium such as paper.

  It is also desirable that the fixing solution contains an oily component to improve permeability and prevent curling of a medium such as paper and form an O / W emulsion or a W / O emulsion. In this case, as a specific dispersant, sorbitan fatty acid esters such as sorbitan monooleate, sorbitan monosterate and sorbitan sesquioleate, and sucrose esters such as sucrose laurate and sucrose stearate are desirable.

  As a method for dissolving the softener or dispersing the microemulsion in the fixing solution, for example, mechanical stirring means such as a homomixer or a homogenizer using a rotary blade, or vibration such as an ultrasonic homogenizer is applied. Means are mentioned. In any means, a strong shear stress is added to the softener in the fixing solution to dissolve or disperse the microemulsion.

  The fixing device supplies a fixing liquid according to the present invention to the toner, and then pressurizes the dissolved or swollen toner with a component (softener) that dissolves or swells at least a part of the resin contained in the toner. You may have a smoothing roller (hard roller). By pressurizing the dissolved or swollen toner with a pair of smoothing rollers (hard rollers), the surface of the layer of the dissolved or swollen toner can be smoothed to give gloss to the toner. Furthermore, by fixing the dissolved or swollen toner into the recording medium, the fixability of the toner to the recording medium can be improved. It goes without saying that the fixing device having such a configuration is also included in the present invention.

[Embodiment of Image Forming Apparatus]
The fixing device of the present invention described above is suitable for an application for fixing a toner image formed on a medium in an image forming apparatus.

  FIG. 21 is a schematic configuration diagram of an embodiment of an image forming apparatus using the fixing device of the present invention. In FIG. 21, reference numeral 200 denotes a fixing device of the present invention. The fixing device 200 has a configuration as shown in FIGS. The image forming apparatus is, for example, a single printer or a printer unit of a copying machine.

  This image forming apparatus is of a so-called tandem type in which image forming units 95 to 98 of black, yellow, magenta, and cyan are arranged in series along an intermediate transfer belt 91 as a toner image carrier. The configuration of each image forming unit is shown in FIG.

  The intermediate transfer belt 91 is stretched around three support rollers 92, 93, 94, and rotates in the direction of arrow A in the figure. An exposure device is disposed above each of the image forming units 95 to 98, but is not shown. For example, when the image forming apparatus is a copying machine, image information of an original is read by a scanner, and electrostatic latent images are formed on the photosensitive drums 106 of the image forming units 95 to 98 according to the image information. Exposures L1 to L4 for writing are irradiated by the exposure apparatus. A secondary transfer device 99 is provided at a position facing the support roller 94 of the intermediate transfer belt 91 with the intermediate transfer belt 91 interposed therebetween. The secondary transfer device 99 includes a secondary transfer belt 102 stretched between two support rollers 100 and 101. As the secondary transfer device 99, a transfer roller may be used in addition to the transfer belt. A belt cleaning device 103 is arranged at a position facing the support roller 92 of the intermediate transfer belt 91 with the intermediate transfer belt 91 interposed therebetween. The belt cleaning device 103 is provided to remove toner remaining on the intermediate transfer belt 91.

  A recording sheet 104 as a recording medium is guided to a secondary transfer unit by a pair of paper feed rollers 105. By pressing the secondary transfer belt 102 against the intermediate transfer belt 91, the toner image on the intermediate transfer belt 91 is transferred to the recording paper 104. The recording paper 104 onto which the toner image has been transferred is conveyed by the secondary transfer belt 102 and sent to the fixing device 200, where the unfixed toner image is fixed on the recording paper. In the fixing device 200, as described above, the film thickness of the foam-like fixing liquid on the coating roller or the coating belt is controlled based on the image information recorded by the exposure device.

  Next, the image forming unit will be described. As shown in FIG. 22, in each of the image forming units 95 to 98, a charging device 107, a developing device 108, a cleaning device 109, and a charge removal device 110 are disposed around the photosensitive drum 106. A primary transfer device 111 is provided at a position facing the photosensitive drum 106 with the intermediate transfer belt 91 interposed therebetween. The charging device 107 is a contact charging type charging device employing a charging roller. The charging device 107 uniformly charges the surface of the photosensitive drum 106 by bringing a charging roller into contact with the photosensitive drum 106 and applying a voltage to the photosensitive drum 106. As the charging device 107, a non-contact charging type charging device using a non-contact scorotron or the like may be employed. The photosensitive drum 106 uniformly charged by the charging device 107 is exposed by a laser beam L from an exposure device (not shown), and an electrostatic latent image is recorded. The developing device 108 causes the toner in the developer to adhere to the electrostatic latent image on the photosensitive drum 106 to visualize the electrostatic latent image. Here, the toners corresponding to the respective colors are made of resin materials colored in the respective colors, and these resin materials are dissolved or swollen by the fixing liquid used in the fixing device. The developing device 108 has a stirring unit and a developing unit (not shown), and the developer that has not been used for development is returned to the stirring unit and reused. The toner concentration in the stirring unit is detected by a toner concentration sensor, and is controlled so that the toner concentration becomes constant. Further, the primary transfer device 111 transfers the toner image visualized on the photosensitive drum 106 to the intermediate transfer belt 91. Here, a transfer roller is employed as the primary transfer device 111, and this transfer roller is pressed against the photosensitive drum 106 with the intermediate transfer belt 91 interposed therebetween. As the primary transfer device 111, a conductive brush, a non-contact corona charger, or the like can be employed. Further, the cleaning device 109 removes the toner remaining on the photosensitive drum 106. As the cleaning device 109, a blade whose tip is pressed against the photosensitive drum 106 can be used. Here, the toner recovered by the cleaning device 109 is recovered and reused by the developing device 108 by a recovery screw and a toner recycling device (not shown). Further, the static elimination device 110 is constituted by a lamp, and initializes the surface potential of the photosensitive drum 106 by irradiating light.

[Fixing device confirmation test]
The results of the fixing performance confirmation experiment conducted on the fixing device of the present invention will be described below.

<Experiment 1>
(Fixing solution prescription)
Diluting solvent: 53% by weight of ion exchange water
Softener: Diethoxyethyl succinate (Croda Croda DES) 10wt%
Propylene carbonate 20wt%
Thickener: Propylene glycol 10wt%
Foam enhancer: Palm fatty acid diethanolamide (1: 1) type (Matsumoto Yushi, Marpon MM)
0.5wt%
Foaming agent: amine palmitate 2.5 wt%
Amristyl myristate 1.5wt%
Amine stearate 0.5wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V)
1wt%
Polyethylene glycol monostearate (Kao Emanon 3199)
1wt%
The dispersant was used to promote the solubility of the softener in the diluent solvent. The fatty acid amine was synthesized from fatty acid and triethanolamine.
First, at the above component ratio, the softening agent was removed at a liquid temperature of 120 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed, and a fixing solution (stock solution before foaming) in which the softener was dissolved was prepared using an ultrasonic homogenizer.

(Large bubble generation means)
The configuration is as shown in FIG. 2. A bottle made of PET resin is used as the liquid fixing solution storage container 1, a tube pump (tube inner diameter: 2 mm, tube material: silicone rubber) is used as the liquid transport pump 2, and the liquid transport pipe 3 is used. A silicone rubber tube having an inner diameter of 2 mm was used. A # 400 stainless steel mesh sheet (opening: about 40 μm) was used as the microporous sheet 6 of the gas / liquid mixing section 4.

(Means for generating fine bubbles from large bubbles)
A double cylinder as shown in FIG. 2 was used. The material of the double cylinder was PET resin. The outer cylinder 7 had an inner diameter of 10 mm and a length of 120 mm, and the inner cylinder 8 had an outer shape of 8 mm and a length of 100 mm. The rotational speed of the inner cylinder 8 was variable in the range of 1000 rpm to 2000 rpm.

(Device configuration)
This is the configuration shown in FIG. The fixing operation was confirmed when the gap between the film thickness control blade 22 and the application roller 20 was set to 25 μm and to 40 μm. As the pressure roller 21, a sponge made of an aluminum alloy roller (φ10 mm) with a core metal and a polyurethane foam material (Inoac product name “Color Foam EMO”) having an outer diameter of Φ50 mm and covered with a heat-shrinkable PFEP shrinkable tube A roller was used. As the application roller 20, a SUS roller (φ30 mm) coated with a PFA resin by baking was used. As the film thickness control blade 22, an aluminum alloy support plate bonded with 1 mm thick parallel glass is used, the glass surface is directed to the coating roller side, and the gap between the coating roller 20 and the glass surface is within a range of 10 μm to 100 μm. I was able to control it. As the defoaming roller 23, a φ7 mm roller obtained by subjecting an aluminum roller having a 0.1 mm groove formed on the surface to a spiral process to a PFA baking process was used. As the cleaning roller 24, an SUS roller (φ10 mm) was used. The paper conveyance speed was set to 150 mm / s.

(result)
Using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh), the liquid transport pump is driven at the timing when the PPC paper (Ricoh T-6200) on which a color unfixed toner image is formed is inserted into the fixing device, and the fixing liquid When the liquid fixer is pumped up from the container and passed through the liquid flow path, the fixer is passed through the part that generates large bubbles and the part that makes the bubbles finer, and the bubble diameter is 5 μm to 30 μm after 1 second from the liquid discharge port. A foam-like fixing solution having fine bubbles could be supplied to the coating roller. The bulk (bulk) density of the foam-like fixing solution was approximately 0.05 g / cm ³ .
The coating test was conducted by changing the distance between the pressure roller and the coating roller to a nip width of 1 mm (nip time 6 ms), 15 mm (nip time 100 ms), and 21 mm (nip time 140 ms). The thickness of the toner layer was 30 to 40 μm.
The toner layer penetration time by the foam-like fixing solution was 80 ms to 100 ms. The coating and fixing results are shown in FIG. At a coating amount of 0.15 g / A4, the film thickness of the foam-like fixer on the coating roller was about 50 μm. The film thickness of the foam-like fixer on the coating roller was about 35 μm at a coating amount of 0.1 g / A4, and the film thickness of the foam-like fixing solution on the coating roller was about 70 μm at a coating amount of 0.15 g / A4. .
As shown in FIG. 23, in the region where the film thickness of the foam-like fixing solution on the coating roller is thicker than the toner layer thickness (the region where the coating amount is 0.15 g / A4 or more), the density of the fixed image is larger at the nip time longer than the toner layer penetration time. The density was such that there was no image loss, and good fixability could be confirmed.
Further, in the region of the foam-like fixer film thickness that is thinner than the toner layer thickness (region where the coating amount is 0.15 g / A4 or more), image omission occurs even when the nip time is 100 ms or more, but as shown in FIG. It is considered that the nip time is shorter than the toner layer permeation time because the toner layer permeation time is extremely long in the region of the foam-like fixing liquid film thickness that is thinner than the toner layer thickness.
Continuous paper feeding was performed in an area where the coating amount was 0.15 g / A4 or more where good fixability was obtained. In the case of using the defoaming roller, no overflow occurred in the foam-like fixing liquid even when 1000 sheets were passed. As a comparison, the same continuous paper passing was performed using a defoaming blade instead of the defoaming roller. In this case, after several tens of sheets were passed, bubbles dropped on the paper, affecting the image. Further, when the cleaning roller was pressed, there was no problem even after 100 sheets were passed. For comparison, in the case where no cleaning roller was provided, it was confirmed that toner particles adhered to the back surface of the paper after several tens of sheets were passed.
As described above, when the film thickness of the foam-like fixing solution on the coating roller was made hotter than the thickness of the toner layer, it was confirmed that good fixing was possible when the nip time was longer than the toner layer penetration time.

<Experiment 2>
(Fixing solution formulation and equipment configuration)
The fixer formulation and the coating device configuration are the same as in Experiment 1, but the fixing test was performed at 15 ° C, 25 ° C, and 35 ° C. FIG. 24 shows the foam viscosity of the foam-like fixing solution at each temperature (according to the measurement of cone plate rotational viscosity, rotor diameter φ60 mm, cone angle 1 degree, rotor gap 3 mm, rotation speed 10 (1 / s). Measurement results at It was found that the foam viscosity changes with temperature (lowering the viscosity at high temperature). As shown in FIG. 10, the toner layer penetration time varies depending on the foam viscosity. Therefore, the data shown in FIG. 24 is used as table data, and a temperature detecting means is provided in the fixing device, and the distance between the application roller and the pressure roller is set so that the nip time becomes equal to or longer than the toner layer penetration time according to the detected temperature signal. A mechanism for adjusting the angle is provided.
(result)
Using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh Co., Ltd.), the environmental temperature was changed between 15 ° C. and 35 ° C., but good fixing without image omission was possible in any use environment. There was no problem even with 1000 continuous sheets.

<Experiment 3>
(Fixing solution prescription)
In order to confirm the effect of the fatty acid alkanolamide (1: 1) type, the same formulation as in Experiment 1 above, the formulation excluding the fatty acid alkanolamide, and the fatty acid alkanolamide instead of the (1: 1) type fatty acid alkanolamide Three types of fixing solutions having the same amount of (1: 2) type (coconut fatty acid diethanolamide (1: 2) type (Matsumoto Yushi Marpon LS)) were used.
(Device configuration)
This is the same as in Experiment 1.
(result)
Using an electrophotographic printer (IpsioColor CX8800, manufactured by Ricoh), a color image of unfixed toner was prepared and a fixing test was performed.
As a result, as shown in Table 1, when a fixer containing a fatty acid alkanolamide (1: 1) type was used, no pinholes occurred in the foam-like fixer film on the coating roller, and good fixing was achieved. Could be done. On the other hand, when a fixer containing no fatty acid alkanolamide or containing (1: 2) type is used, fine pinholes (about φ0.5 mm) are generated in the foam-like fixer film on the coating roller. Innumerable pinhole-like fixing defects occurred in the toner image after fixing. Moreover, when the foam-like fixing solution containing the fatty acid alkanolamide (1: 1) type was used, there was no problem even with 1000 continuous sheets of paper, and the effect of containing the fatty acid alkanolamide (1: 1) type could be confirmed. .

It is a schematic diagram of a foam-like fixing solution. It is a block diagram of a means for generating a foam-like fixing solution from a liquid fixing solution. FIG. 2 is a schematic configuration diagram of a fixing device using a foam-like fixing liquid. FIG. 4 is a schematic diagram illustrating a state in which a foam-like fixing liquid is applied to a toner layer. It is explanatory drawing of film thickness adjustment of the foam-form fixing liquid film | membrane by a film thickness control blade. It is explanatory drawing regarding toner adhesion to a coating roller. It is a schematic diagram for demonstrating the penetration | infiltration state to the fine particle layer of foam-form fixing solution. It is a schematic diagram for demonstrating the penetration | infiltration state to the fine particle layer of foam-form fixing solution. It is a schematic diagram of an osmosis time measuring device. It is a graph which shows the relationship between foam-like fixing liquid film thickness and osmosis | permeation time. It is a graph which shows the relationship between the pressure at the time of application | coating, and osmosis | permeation time. It is a graph which shows the relationship between foam viscosity and osmosis | permeation time. 1 is a schematic configuration diagram showing an embodiment of a fixing device according to the present invention. It is a figure which shows the defoaming roller etc. which were seen from A direction of FIG. It is a figure which shows the example which installs the fixing liquid sneaking prevention cover in the defoaming roller. It is a figure which shows a defoaming blade. It is a figure which shows the defoaming blade etc. which were seen from the B direction of FIG. It is a schematic block diagram which shows other embodiment of the fixing device which concerns on this invention. It is a schematic block diagram which shows other embodiment of the fixing device which concerns on this invention. It is a schematic block diagram which shows other embodiment of the fixing device which concerns on this invention. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus according to the present invention. It is a schematic block diagram of each image forming unit in FIG. 6 is a graph illustrating the results of a fixing performance confirmation experiment. 6 is a graph illustrating the results of a fixing performance confirmation experiment. FIG. 2 is a schematic diagram of a fixing device using a liquid fixing solution. FIG. 6 is an explanatory diagram of toner adhesion to a coating roller of a fixing device using a liquid fixing liquid.

Explanation of symbols

20 Application roller 21 Pressure roller 22 Film thickness control blade 23 Defoaming roller 24 Cleaning roller 28 Absorbing sponge 30 Defoaming blade 31 Application belts 32, 33 Pressure belt 200 Fixing device

Claims (12)

A fixing device for fixing fine particles containing unfixed resin on a medium to the medium,
A roller-shaped or belt-shaped coating member; and a pressure member for pressing the medium against the coating member, the unfixed fine particles on the medium passing between the coating member and the pressure member On the other hand, a fixing solution applying means for pressing a film of a foam-like fixing solution formed on the coating member and containing a softening agent that softens the resin;
And a defoaming means for defoaming and re-liquefying the foam-like fixing solution remaining without adhering to the fine particles on the coating member.   The fixing device according to claim 1, further comprising a fixing solution collecting unit that collects the fixing solution reliquefied by the defoaming unit.   The defoaming means comprises a roller-shaped defoaming member that rotates while in contact with the application member, and sandwiches the foam-like fixing liquid remaining on the application member between the defoaming member and the application member. The fixing device according to claim 1, wherein the defoaming is performed by using the fixing device.   The fixing device according to claim 3, wherein a spiral groove is formed on a surface of the defoaming member.   The defoaming means comprises a blade-shaped defoaming member that comes into contact with the application member, and a foam-like shape remaining on the application member between the contact portion of the defoaming member and the application member. The fixing device according to claim 1, wherein the fixing device performs defoaming by squeezing the fixing solution.   The fixing device according to claim 5, wherein the defoaming member is disposed to be inclined from a horizontal position.   The fixing device according to claim 3, wherein the fixing liquid recovery unit includes a liquid absorbing sponge member provided near an end of the defoaming member.   The fixing device according to claim 1, further comprising a particulate collection unit that collects the particulate attached to the pressure member.   The said fine particle collection | recovery means consists of a roller-shaped member with the surface which has strong adhesiveness with the said fine particle compared with the said pressurization member rotated while contacting the said pressurization member. Fixing device.   The fixing device according to claim 1, wherein at least one of the application member and the pressure member is a roller-like member having elasticity.   The fixing device according to claim 1, wherein at least one of the application member and the pressure member is a belt-shaped member. Means for forming an unfixed toner image on the medium;
An image forming apparatus comprising: the fixing device according to claim 1, which performs a process of fixing an unfixed toner image formed on the medium to the medium.

Images