JP2012003115A - Defoaming, fixing and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a defoaming device being capable of making a liquid fixing solution by deforming a foamed fixing solution with smaller energy than those of heating, as well as a fixing and imaging device therewith.SOLUTION: A defoaming device 80 being provided with a fixing device 30 dissolves or swells at least a part of toner as a resin component, breaks foams of a foamed fixing solution Bu in which air bubbles are scattered in a fixing liquid F to be fixed on a transfer paper P as a record medium to make a liquid fixing solution TL. The defoaming device 80 breaks foams of the foamed fixing solution Bu with a defoaming solution BL including a defoaming agent.

Description

  The present invention is an erasing method in which at least part of a resin component such as toner is dissolved or swollen to break up a foamy fixing solution in which bubbles are dispersed in a fixing solution that is fixed on a recording medium, thereby forming a liquid fixing solution. The present invention relates to a foam device, and a fixing device and an image forming apparatus including the foam device.

  Image forming apparatuses such as printers, facsimile machines, and copying machines are apparatuses that form images including characters and symbols on recording media such as paper, cloth, and OHP sheets based on image information. There are various types of image forming apparatuses, and electrophotographic image forming apparatuses are widely used in offices because they can form high-definition images on plain paper at high speed. In this electrophotographic image forming apparatus, the toner on the recording medium is heated and softened or melted from the viewpoint of fixing speed, fixed image quality, etc., and the softened toner is pressed to apply the toner onto the recording medium. The heat fixing method for fixing to the surface is widely spread. This thermal fixing method is suitably used because it can provide a high fixing speed and high fixed image quality.

However, more than half of the power consumption in the electrophotographic image forming apparatus including the fixing device adopting such a heat fixing method is consumed for heating the toner in the fixing device. On the other hand, from the viewpoint of measures against environmental problems in recent years, an image forming apparatus with low power consumption (energy saving) is desired. Therefore, there is a demand for energy saving in the fixing device that consumes more than half of the power consumption in the conventional image forming apparatus. The conventional heat fixing type fixing device consumes a lot of electric power for the heat treatment, so the fixing method for heating the toner to fix the toner is extremely lower than before, or the toner is heated. A fixing method that does not require this is desired. In particular, a non-heat fixing method in which toner is fixed on a recording medium without heating the toner is ideal in terms of low power consumption.
In such a non-heat fixing method, a toner image is formed by applying a fixing solution containing a softening agent that softens the toner by dissolving or swelling at least a part of the resin component of the toner to the toner image on the surface of the recording medium. There is known a wet fixing method for fixing a toner (for example, a fixing method used in a fixing device described in Patent Documents 1 to 4). As described above, the wet fixing type fixing device does not need to perform heat treatment to soften the toner, so that energy saving can be realized as compared with the thermal fixing method.

  In any of the fixing devices described in Patent Documents 1 to 3, the fixing liquid is applied to the recording medium in a liquid state by using a coating roller that is a contact-type fixing liquid application unit. In this configuration, the toner image is applied to an unfixed toner image on the recording medium. In a configuration in which such a liquid fixing solution is applied to a toner image for fixing, it is extremely difficult to achieve both the application of a small amount of the fixing solution to the toner image on the recording medium and the prevention of toner offset to the application roller. was there. Hereinafter, this problem will be described.

  In the configuration in which the fixing liquid is applied to the unfixed toner image on the recording medium using the application roller, the thickness of the fixing liquid layer on the application roller is set to When it was made thinner than the layer, the following problem sometimes occurred. After the surface of the coating roller comes into contact with the recording medium, the surface of the coating roller peels from the recording medium, and the surface tension generated by the liquid film of the fixing liquid not applied to the recording medium and remaining on the surface of the coating roller The toner particles in the toner layer are pulled. As a result, offset toner particles adhere to the surface of the coating roller, and the toner image on the recording medium after peeling off from the coating roller is greatly disturbed.

  Conversely, if the thickness of the fixing liquid layer on the application roller is sufficiently thicker than the unfixed toner layer, the surface tension of the application roller surface due to the liquid film is large because the amount of liquid is large at the position where the application roller peels off the recording medium. Is less likely to act on the toner particles of the toner layer on the recording medium. This makes it difficult for toner to adhere to the application roller side. However, since a large amount of the fixing solution is applied to the surface of the recording medium, toner particles flow due to the diffusion of the fixing solution due to the excessive fixing solution on the recording medium, and the image quality deteriorates or the drying time of the fixing solution becomes long. A problem may occur in the fixing response. In addition, a remarkable residual liquid feeling (a wet feeling when touching paper) is generated on the recording medium. In addition, when the fixing solution contains water, when the amount of the fixing solution applied to the recording medium containing cellulose such as paper is large, the recording medium such as paper curls remarkably, and the image forming apparatus or the like There is a risk of paper jams when the recording medium is transported inside.

As described above, in the configuration in which the liquid fixing solution is applied using the application roller, if the amount of the fixing solution applied is too large, the image quality is deteriorated due to the flow of toner particles, and the fixing time is increased due to the longer drying time of the fixing solution. There arises a problem that the responsiveness is lowered and a paper jam is likely to occur depending on the recording medium. On the other hand, when a small amount of liquid fixer is applied in order to prevent these problems, the toner particles are offset on the surface of the application roller as described above.
Therefore, in the configuration in which the liquid fixing liquid is applied using the application roller, a small amount of the fixing liquid is applied to the toner layer on the recording medium in order to improve the fixing response, reduce the residual liquid feeling, and prevent curling, and the application roller. It is extremely difficult to achieve both the prevention of toner offset against the toner.

  As a fixing method capable of satisfying both the application of a small amount of fixing solution and the prevention of toner offset, Patent Document 4 discloses that the fixing solution is a foam-like fixing solution in which bubbles are dispersed in the solution, and this foam-like fixing solution is recorded. A configuration for applying to a toner image on a medium is described. In this way, since the bulk density of the fixing solution can be lowered by making the fixing solution foamy, the film thickness of the fixing solution on the surface of the application roller can be increased with a smaller amount of fixing solution than before, The influence of the surface tension of the liquid on the toner particles on the recording medium can be reduced. In addition, since the amount of the fixing solution is small, the residual liquid feeling on the recording medium can be suppressed, and the foamy fixing solution is less likely to flow than the liquid fixing solution. Deterioration can also be prevented. Therefore, by performing fixing using a foamy fixing solution as in Patent Document 4, it is possible to fix the toner image without disturbing the toner with a smaller amount of fixing solution applied than before.

In the case of a configuration in which a foam-like fixing solution is applied to a recording medium using an application member whose surface moves endlessly, such as a fixing roller described in Patent Document 4, the foam-like fixing solution is applied to the recording medium. It is desirable to provide a foam fixing solution collecting means for collecting the foam fixing solution from the surface of the subsequent coating member. This is because the remaining foamy fixing solution remaining on the surface of the coating member after the coating member has passed through the coating position where the foaming fixing solution is applied to the recording medium is not adhered to the recording medium. This is for recovering the residual foamy fixing solution.
Since the residual foam-fixing solution is supplied as a foam-fixing solution to the coating member, time has passed and a mechanical force is applied at the coating position, so a part of the foam is defoamed. For example, it is conceivable that the bulk density of the foam-like fixer is higher than when it is supplied to the application member. For this reason, when a new foam-like fixing solution is supplied to the coating member while the remaining foam-like fixing solution remains on the coating member, the foam-like fixing solutions having different bulk densities are mixed and the foam-like fixing solution is applied to the recording medium. There is a risk that it cannot be applied uniformly.
In addition, the residual foam-like fixer may contain a small amount of offset toner. For this reason, when the residual foamy fixing liquid remaining on the application member reaches the application position again, the offset toner may move to the recording medium, and the image quality may be deteriorated.
In order to prevent such problems caused by the residual foam fixing solution, it is desirable to recover the residual foam fixing solution from the surface of the coating member in a fixing device that performs fixing using the foam fixing solution.

  However, the foam-like fixer recovered as the residual foam-fixing solution has a higher bulk density than when it was supplied to the coating member, but compared with a liquid fixer (hereinafter referred to as a liquid fixer). Therefore, the bulk density is low and the bulk with respect to the mass is large. Since the fixing solution is foamy, the volume may swell several tens of times that of the liquid fixing solution that is not foamed. For this reason, a large container is required to contain the fixing solution in the form of foam. The foam-type fixing solution naturally defoams over time and the volume gradually decreases. However, since it takes time to defoam naturally, it is collected from the coating member and defoamed to support continuous printing. A large container is needed to store the previous foamy fixer. If a large container capable of accommodating such a foam-like fixing solution is arranged in the image forming apparatus, there is a problem that the apparatus is increased in size.

For this reason, it is required that the residual foamy fixing solution is liquefied and stored in a liquid fixing solution. As a configuration in which the foam-like fixing solution is a liquid fixing solution, an anti-foaming device that defoams the foam-like fixing solution by heating to break the bubbles can be considered.
However, the configuration in which a defoaming device that heats and breaks the foam fixing solution in the fixing device that performs fixing using the foam fixing solution requires energy for the heat treatment to break the bubbles, and wet fixing. Adopting this method reduces the advantage of saving energy compared to the thermal fixing method.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a defoaming apparatus capable of defoaming a foamy fixing solution with less energy than heating to obtain a liquid fixing solution. And a fixing device and an image forming apparatus.

In order to achieve the above object, the invention of claim 1 breaks down a foamy fixing solution in which bubbles are dispersed in a fixing solution that dissolves or swells at least a part of a resin component and fixes it on a recording medium. In the defoaming device that is used as a liquid fixer, the foamy fixer is defoamed by an antifoaming agent.
Further, the invention of claim 2 is the antifoaming device of claim 1, further comprising a fixing solution recovery container for recovering and storing the foamy fixing solution, wherein the antifoaming agent is contained in the fixing solution recovery container. The antifoaming liquid is contained, and the recovered foamy fixing liquid is brought into contact with the antifoaming liquid to break up the foamy fixing liquid and mixed with the antifoaming liquid as a liquid fixing liquid. The antifoaming agent is added stepwise to the antifoaming liquid according to the amount of the antifoaming liquid mixed with the liquid fixing liquid in the collection container.
According to a third aspect of the present invention, in the antifoaming device according to the second aspect, the antifoaming agent is attached to a part of the fixer recovery container.
According to a fourth aspect of the present invention, there is provided the antifoaming apparatus according to the third aspect, wherein an antifoaming agent containing member for containing the antifoaming agent is attached to an inner wall surface of the fixer recovery container, and the antifoaming agent containing member is The antifoaming liquid is made of a material that dissolves when contacted, and the antifoaming agent storage member is dissolved by the antifoaming liquid in the fixer collecting container so that the stored antifoaming agent is contained in the antifoaming liquid. It is characterized by being added.
According to a fifth aspect of the present invention, in the antifoaming device according to any one of the second to fourth aspects, the antifoaming agent is attached to a plurality of locations having different heights on the inner wall surface of the fixer recovery container. It is characterized by that.
The invention according to claim 6 is the antifoaming device according to any one of claims 2 to 5, wherein the antifoaming liquid is added to the defoaming liquid according to the amount of the antifoaming liquid in the fixer recovery container. The amount of the antifoaming agent added stepwise is increased as the amount of the antifoaming solution increases.
The invention of claim 7 is the antifoaming device according to any one of claims 2 to 6, further comprising a stirring means for stirring the antifoaming liquid in the fixer recovery container. Is.
Further, the invention of claim 8 relates to a fixer bubble in which a liquid fixer containing a softening agent that softens resin fine particles by dissolving or swelling at least part of a resin is used as a foamy fixer in which bubbles are dispersed in the solution. And a foam-like fixing solution applying means for applying the foam-like fixing solution to the surface of the fixing solution application target carrying the resin fine particle layer composed of the resin fine particles, and applying the foam-like fixing solution. In the fixing device for fixing the resin fine particles softened to the recording medium, the foam-like fixing solution is collected, and the foam-like fixing solution defoaming means is used for recovering the bubbles and breaking the bubbles to form the liquid fixing solution. As a liquid defoaming means, the defoaming apparatus according to any one of claims 1 to 7 is used.
Further, the invention of claim 9 is the fixing device according to claim 8, wherein the foamed fixing solution becomes the foamed fixing solution by the fixing solution foaming means and is not applied to the fixing solution application target but attached to the surface moving body. Foam fixer cleaning means for collecting and cleaning the foam fixer is provided, and the foam fixer recovered by the foam fixer cleaning means is combined with the liquid fixer by the foam fixer defoaming means. It is characterized by doing.
According to a tenth aspect of the present invention, there is provided a toner image forming means for forming a toner image on a recording medium using a toner containing resin fine particles containing a resin and a colorant, and a toner carrying a toner image transferred to the recording medium. An image forming apparatus comprising: a fixing unit that applies a fixing liquid to a surface of an image carrier or a surface of a recording medium that carries a toner image, and fixes the toner image on the recording medium. The fixing device according to claim 8 or 9 is used.

  According to the present invention, since the foam fixing solution is broken by the antifoaming agent, there is an excellent effect that the foam fixing solution can be defoamed with less energy than heating to obtain a liquid fixing solution. .

Explanatory drawing of the fixing device which shows the outline of a bubble collection | recovery apparatus. 1 is a schematic configuration diagram illustrating a main part of a printer according to an embodiment. FIG. 2 is an enlarged configuration diagram illustrating a process unit of the printer. 1 is a schematic configuration diagram of a fixing device according to an embodiment. FIG. 3 is a configuration diagram of a foamy fixing solution supply unit of the fixing device of the present embodiment. FIG. 3 is a configuration diagram of a foamy fixing solution application unit of the fixing device according to the embodiment. The perspective explanatory drawing of an application roller and a film thickness adjustment blade. FIG. 3 is an enlarged schematic diagram illustrating a film thickness adjusting blade and a coating roller in the fixing device. FIG. 9 is an enlarged schematic diagram illustrating a film thickness adjusting blade and a coating roller in a state where the film thickness adjusting gap is narrower than that in FIG. 8. The enlarged schematic diagram which expands and shows the coating roller surface and transfer paper in a coating nip. The enlarged schematic diagram which shows a foamy fixing solution. The top view of a foam collection belt. The perspective enlarged view of a defoaming apparatus. The expansion explanatory drawing of an antifoamer holder. 1 is a schematic configuration diagram of a fixing device including a pressure belt. An explanatory view when the film thickness of the fixing solution is thin in a fixing device using a liquid fixing solution, (a) is a schematic explanatory view of the fixing device, and (b) is an application roller that contacts the transfer paper and applies the fixing solution. Explanatory drawing of the application | coating position where a transfer paper contacts. FIG. 3 is an explanatory diagram when the film thickness of the fixing solution is sufficiently thick in the fixing device using the liquid fixing solution.

Hereinafter, an embodiment of an electrophotographic tandem color printer (hereinafter simply referred to as a printer 100) will be described as an image forming apparatus to which the present invention is applied. The image forming apparatus to which the present invention is applied is not limited to a printer, and any image forming apparatus having a fixing device such as a copying machine or a facsimile can be applied.
First, a basic configuration of the printer 100 according to the embodiment will be described. FIG. 2 is a schematic configuration diagram illustrating a main part of the printer 100. In the figure, a printer 100 includes four process units 3 (Y, M, C, K) that form yellow (Y), magenta (M), cyan (C), and black (K) toner images, and a transfer unit. 20, a paper transport unit 28, a registration roller pair 15, a fixing device 30, an optical writing device (not shown), and the like.
The transfer unit 20 includes an intermediate transfer belt 25 as a toner image carrier, and is an image forming unit for each color of black, yellow, magenta, and cyan along a stretched surface on the upper side of the intermediate transfer belt 25. Four process units 3 (Y, M, C, K) are arranged.

  An optical writing device (not shown) is arranged above the four process units 3 (Y, M, C, K). For example, when the printer 100 is a copying machine, image information of an original is read by a scanner, and a light source such as a laser diode or an LED of an optical writing device is driven according to the image information, thereby processing unit 3 ( The respective laser beams L1 to L4 are irradiated toward the drum-shaped photoconductor 4 (Y, M, C, K) in Y, M, C, K). By this irradiation, an electrostatic latent image is formed on the surface of the photoreceptor 4 (Y, M, C, K), and this latent image becomes a toner image through a predetermined development process. The subscripts Y, M, C, and K added after the reference numerals indicate the specifications for yellow, magenta, cyan, and black.

Each of the process units 3 (Y, M, C, K) supports the photosensitive member 4 serving as a latent image carrier and various devices disposed around the photosensitive member 4 as a single unit on a common support. The printer body is detachable. The process unit 3 (Y, M, C, K) has the same configuration except that the color of the toner to be used is different, and FIG. 3 shows the structure of the four process units 3 (Y, M, C, K). 4 is an enlarged explanatory diagram of one process unit 3. FIG.
As shown in FIG. 3, each of the four process units 3 includes a developing device 6, a charging device 7, a static elimination lamp 8 of a static elimination device, a drum cleaning device 9, and the like in addition to the photoreceptor 4. In addition, a primary transfer roller 26 of a primary transfer device is provided at a position facing the photoconductor 4 with the intermediate transfer belt 25 interposed therebetween.
The primary transfer device according to the present embodiment includes a roller-shaped primary transfer roller 26 as a primary transfer member, and the primary transfer roller 26 contacts the photoconductor 4 with the intermediate transfer belt 25 interposed therebetween, so that the surface of the photoconductor 4 is exposed. A primary transfer nip for transferring the toner image formed on the intermediate transfer belt 25 is formed. As the primary transfer member, a conductive brush, a non-contact corona charger, or the like can be employed.

As the photoreceptor 4, a drum-shaped member is used in which a photosensitive layer is formed by applying a photosensitive organic photosensitive material to a base tube made of aluminum or the like. The photoreceptor is not limited to a drum shape, but may be an endless belt shape.
The charging device 7 of the present embodiment is a contact-type charging device in which a charging roller to which a charging bias is applied is brought into contact with the photosensitive member 4. The charging device 7 uniformly charges the surface of the photosensitive member 4 by applying a charging bias to the charging roller that is in contact with the photosensitive member 4. The charging device 7 is not limited to the contact-type charging method, and a non-contact charging method charging device that employs a scorotron charger that performs a non-contact charging process on the photoconductor 4 may be used.

The developing device 6 obtains a toner image by attaching toner to the electrostatic latent image on the photoreceptor 4 using a two-component developer containing a magnetic carrier (not shown) and a non-magnetic toner. This is a two-component phenomenon system that develops and visualizes. Instead of the two-component developer, a one-component phenomenon type developing with a one-component developer not containing a magnetic carrier may be used. The toner image developed on the surface of the photoreceptor 4 is primarily transferred to the intermediate transfer belt 25 at the primary transfer nip.
Here, the toner corresponding to each color is composed of resin fine particles colored in the respective colors, and these resin fine particles are dissolved or swollen by a fixing solution described later. The developing device 6 includes a stirring unit that contains and stirs the two-component developer, and a developing unit in which the developing roller is disposed. The developer that is supplied to the surface of the developing roller and is not used for development is a stirring unit. To be reused. The toner concentration of the two-component developer in the stirring unit is detected by a toner concentration sensor (not shown) and is controlled so that the toner concentration is constant.

Transfer residual toner adhering to the surface of the photoconductor 4 after passing through the primary transfer nip is removed from the surface of the photoconductor 4 by the drum cleaning device 9. The transfer residual toner removed from the surface of the photoreceptor 4 by the drum cleaning device 9 is transported to the developing device 6 by a not-shown recovery screw and toner recycling device and reused. In the present embodiment, as the drum cleaning device 9, a system that scrapes off the transfer residual toner with a polyurethane rubber cleaning blade is shown.
The neutralization lamp 8 neutralizes the surface of the photoreceptor 4 by light irradiation.

When the process unit 3 forms a toner image on the surface of the photoconductor 4, the surface of the photoconductor 4 that rotates counterclockwise in FIGS. 2 and 3 is uniformly charged by the charging device 7. The uniformly charged surface of the photoconductor 4 is irradiated with laser light L based on image information from an optical writing device (not shown), and an electrostatic latent image is formed on the surface of the photoconductor 4. Thereafter, the electrostatic latent image is developed on the surface of the photoconductor 4 by the developing device 6, and a toner image is formed on the surface of the photoconductor 4.
The surface of the photoreceptor 4 on which the toner image is formed is transferred onto the surface of the photoreceptor 4 after the toner image is transferred to the intermediate transfer belt 25 at a primary transfer nip that is a portion facing the primary transfer roller 26 and passed through the primary transfer nip. The remaining transfer residual toner is removed by the drum cleaning device 9. The surface of the photoreceptor 4 from which the transfer residual toner has been removed is neutralized by light irradiation of the neutralization lamp 8 and initialized, and is prepared for the next image formation starting from uniform charging by the charging device 7.

  In FIG. 2, Y, M, C, and K toner images are formed on the photoreceptors 4 (Y, M, C, and K) of the four process units 3 (Y, M, C, and K) by the above-described process. The A transfer unit 20 is disposed below the four process units 3 (Y, M, C, K). In the transfer unit 20, an intermediate transfer belt 25 stretched by a plurality of stretching rollers (21, 22, 23) is brought into contact with the photosensitive member 4 (Y, M, C, K) to thereby make Y, M , C, K primary transfer nips are formed. The intermediate transfer belt 25 is moved endlessly in the clockwise direction in the figure (in the direction of arrow A in the figure) by the rotational drive of the drive roller 21.

  In the vicinity of the primary transfer nip for Y, M, C, and K, the intermediate transfer belt 25 is moved to the photosensitive member by the primary transfer roller 26 (Y, M, C, and K) disposed inside the belt loop of the intermediate transfer belt 25. 4 (Y, M, C, K). A primary transfer bias is applied to these primary transfer rollers 26 (Y, M, C, K) by a power source (not shown). As a result, a primary transfer electric field for electrostatically moving the toner image on the photoreceptor 4 (Y, M, C, K) toward the intermediate transfer belt 25 is present in the primary transfer nips for Y, M, C, and K. Is formed. As shown in FIG. 2, each of the color transfer toners passes through the primary transfer nips for Y, M, C, and K in sequence with the endless movement in the clockwise direction. The images are sequentially superimposed and primarily transferred. By this primary transfer of superposition, a four-color superposed toner image (hereinafter referred to as a four-color toner image) is formed on the front surface of the intermediate transfer belt 25.

  A paper transport unit 28 that functions as a secondary transfer device is provided at a position facing the transfer backup roller 23 across the intermediate transfer belt 25 below the transfer unit 20 in the drawing. The paper transport unit 28 is configured to endlessly move an endless paper transport belt 29 between two support rollers of a driving roller 29b and a secondary transfer roller 29a. The paper transport unit 28 sandwiches the paper transport belt 29 between its secondary transfer roller 29 a and the intermediate transfer belt 25 of the transfer unit 20. With such a configuration, a secondary transfer nip is formed in which the front surface of the intermediate transfer belt 25 and the front surface of the paper transport belt 29 abut. The secondary transfer device is not limited to the configuration in which the belt-shaped member is opposed to the intermediate transfer belt 25, but may be configured to have the roller-shaped member be opposed to the intermediate transfer belt 25.

  A secondary transfer bias is applied to the secondary transfer roller 29a of the paper transport unit 28 by a power source (not shown). On the other hand, the transfer backup roller 23 around which the intermediate transfer belt 25 is wound in the loop of the intermediate transfer belt 25 of the transfer unit 20 is grounded. As a result, a secondary transfer electric field acting so that the four-color toner image on the intermediate transfer belt 25 is directed to the secondary transfer roller 29a is formed in the secondary transfer nip.

In the secondary transfer nip, the four-color toner image on the intermediate transfer belt 25 is transferred to a transfer paper P that is a recording medium supplied from a paper supply device (not shown).
A registration roller pair 15 is disposed on the right side of the secondary transfer nip in the drawing, and the secondary transfer nip 15 is synchronized with the four-color toner image on the intermediate transfer belt 25 at the timing when the transfer paper P sandwiched between the rollers is synchronized. Send to transfer nip. In the secondary transfer nip, the four-color toner images on the intermediate transfer belt 25 are collectively transferred to the transfer paper P due to the influence of the secondary transfer electric field and the nip pressure, and combined with the white color of the transfer paper P, a full color image is formed. The transfer paper P that has passed through the secondary transfer nip is separated from the intermediate transfer belt 25 and is conveyed to the fixing device 30 along with its endless movement while being held on the front surface of the paper conveyance belt 29.

  A belt cleaning device 24 is disposed at a position facing the cleaning counter roller 22 among the plurality of stretching rollers (21, 22, 23) of the intermediate transfer belt 25 with the intermediate transfer belt 25 interposed therebetween. The transfer residual toner that has not been transferred to the transfer paper P at the secondary transfer nip adheres to the surface of the intermediate transfer belt 25 that has passed through the secondary transfer nip, and this transfer residual toner is intermediated by the belt cleaning blade 24a. It is scraped off and removed by a belt cleaning device 24 in contact with the transfer belt 25.

Next, the fixing device 30 will be described. FIG. 4 is a schematic configuration diagram of the fixing device 30 according to the embodiment.
In the following, for the sake of convenience, a fixing solution in a normal liquid state without bubbles is referred to as “liquid fixing solution TL”, and a fixing solution that contains bubbles in the solution and becomes foamed is referred to as “foamed fixing solution Bu”. That's it. Further, among the foam-like fixing solution Bu, the foam-like fixing solution Bu that has been bubbled from the state of the liquid fixing solution TL and whose bubble diameter is larger than the desired bubble diameter is referred to as “initial foam-like fixing solution Bu1”. The foam-like fixer Bu that has been bubbled from the initial foam-like fixer Bu1 to have a desired bubble diameter is referred to as “small-diameter foam-fixer Bu2”. Further, the small-diameter foam-like fixer Bu2 that is regulated by the foam-like fixer film thickness control means on the surface of the application roller 41, which will be described later, is referred to as a foam-like fixer film Bu3. Further, the foamy fixing solution Bu remaining on the surface of the coating roller 41 after passing through the coating nip C described later in detail is referred to as a residual foamed fixing solution Bu4. A fixing solution that is not limited to any state is referred to as a fixing solution F.

The fixing device 30 shown in FIG. 4 includes a foam-like fixing liquid application unit 140 that is a fixing liquid application unit that applies the fixing solution F to the transfer paper P, and a foam-type fixing solution supply unit 130 that is a foam-like fixing solution generation unit. Is provided. Then, the foamy fixer Bu generated by the foamy fixer supply unit 130 is applied to the unfixed toner T on the transfer paper P by the foamy fixer application unit 140. The foam-like fixing liquid application unit 140 includes an application roller 41 and a pressure roller 43.
The foam-like fixing solution supply unit 130 includes a gas / liquid mixing unit 35 that generates the initial foam-like fixing solution Bu1, and a fine bubble that generates a small-diameter foam-like fixing solution Bu2 by applying shearing force to the initial foam-like fixing solution Bu1. And a conversion unit 38.

In the fixing device 30, as two fixing liquids constituting the liquid fixing liquid TL, a liquid containing a softener (hereinafter referred to as a softener liquid 310a) and a liquid containing a foaming agent (hereinafter referred to as a foaming agent liquid). 310b) is stored separately. The softening agent liquid 310a and the foaming agent liquid 310b are mixed in the liquid mixing unit 400 when the foamy fixing solution Bu is generated, and the liquid fixing solution TL obtained by this mixing is mixed with the foamy fixing solution supply unit 130. To generate a foamy fixing solution Bu.
As a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin, there are those that react with water and hydrolyze. For this reason, the foaming agent liquid 310b containing water and the softening agent liquid 310a are stored separately as in the fixing device 30 of this embodiment, and mixed immediately before generating the foamy fixing liquid Bu in use. It is desirable to use.

  FIG. 5 is an enlarged configuration diagram illustrating the foamy fixing solution supply unit 130 of the fixing device 30, and FIG. 6 is an enlarged configuration diagram illustrating the foamed fixing solution application unit 140 of the fixing device 30. FIG. 7 is a perspective explanatory view of the application roller 41 and the film thickness adjusting blade 42 provided in the fixing device 30 as viewed from the direction of arrow G in FIG.

The foam-like fixing liquid supply unit 130 is obtained by mixing the softener liquid 310a accommodated in the softener liquid container 31a and the foaming liquid 310b accommodated in the foaming liquid container 31b. The obtained liquid fixing solution TL is bubbled, and the obtained foamy fixing solution Bu is supplied onto the surface of the application roller 41.
The softener liquid 310a in the softener liquid container 31a is supplied to the liquid mixing unit 400 through the softener liquid transport pipe 34a by driving the softener liquid transport pump 33a. Further, the foaming agent liquid 310b in the foaming agent liquid container 31b is supplied to the liquid mixing unit 400 through the foaming agent liquid transporting pipe 34b by driving the foaming agent liquid transporting pump 33b.
At this time, the drive of the softener liquid transport pump 33a and the foaming liquid transport pump 33b is controlled to adjust the ratio between the transport amount of the softener liquid 310a and the transport amount of the foaming liquid 310b. Thus, by adjusting the ratio of the transport amounts of the two liquids, the mixing ratio of the softener liquid 310a and the foaming liquid 310b in the liquid fixing liquid TL formed by mixing the two liquids can be adjusted. . The softening agent liquid 310a and the foaming agent liquid 310b supplied at a predetermined mixing ratio are mixed in the liquid mixing unit 400, and the liquid fixing liquid TL obtained by the mixing is gasified via the liquid fixing liquid transport pipe 340. -It conveys to the liquid mixing part 35.

  As the liquid transport pump 33 (33a and 33b), a gear pump, a bellows pump, a tube pump, or the like can be used. Among these, it is desirable to use a tube pump. If there is a part that constitutes a vibration mechanism or a rotation mechanism in the path through which the fixing liquid passes, such as a gear pump, the liquid bubbles in the pump, the liquid becomes compressible, and the conveying capacity decreases. There is a fear. Also, if there is a part that constitutes a vibration mechanism or a rotation mechanism in the path of the fixing liquid, the material of the part melts and contaminates the fixing liquid, or conversely, the fixing liquid deteriorates the part. There is a fear.

On the other hand, the tube pump is a mechanism that pushes out the liquid in the tube while deforming the tube. There are no parts that make up the vibration mechanism or rotation mechanism in the path of the fixing liquid, and only the tube is in contact with the fixing liquid. It is. For this reason, by using a member having liquid resistance to the fixing liquid conveyed as a tube, it is possible to prevent contamination of the fixing liquid and deterioration of components constituting the liquid conveying pump 33. Further, since only the tube is deformed, the fixing liquid does not foam, and it is possible to prevent a decrease in conveying ability due to the foaming of the liquid.
The liquid transported by the liquid transport pump 33 is not limited to the softener liquid 310a and the foaming liquid 310b, but is transported when transported from a fixing liquid container that stores the liquid fixing liquid TL itself as a fixing liquid. It is desirable to use a tube pump as the pump 33 as well. In this case, by using a member having liquid resistance to the fixing liquid F as the tube, it is possible to prevent liquid contamination and deterioration of the components constituting the liquid transport pump 33.

  The gas / liquid mixing unit 35 is provided with an air port 36, and the liquid fixer TL that flows into the gas / liquid mixing unit 35 by driving the softener liquid transfer pump 33 a and the foaming agent liquid transfer pump 33 b. And a negative pressure is generated at the air port 36. As a result, air is introduced from the air port 36 into the gas / liquid mixing unit 35, the liquid fixer TL and air are mixed, and further pass through the microporous sheet 37, thereby forming large bubbles with uniform bubble diameters. An initial foam fixing solution Bu1 can be generated.

The hole diameter of the microporous sheet 37 is, for example, about 30 to 100 [μm]. The configuration for foaming the liquid fixing solution TL is not limited to the configuration including the microporous sheet 37 as in the foam-like fixing solution supply unit 130 shown in FIG. . For example, a sintered ceramic plate, a nonwoven fabric, a foamed resin sheet, or the like having communication holes with a hole diameter of about 30 [μm] to 100 [μm] may be used.
As another generation method for generating the initial foam-like fixing solution Bu1 composed of large bubbles from the liquid fixing solution TL, there is a method of stirring the liquid fixing solution TL and air with a blade-like stirrer. In this method, the liquid fixer TL and air are fed into a stirring vessel in which a blade-like stirrer is arranged, and bubbles are entrained in the liquid fixer TL by stirring with the blade-like stirrer to generate an initial foam-like fixer Bu1. To do.
Alternatively, a method may be employed in which the liquid fixing solution TL is stored in the fixing solution storage container, and the stored liquid fixing solution is bubbled with an air supply pump or the like to generate the initial foamy fixing solution Bu1.

  Regardless of the configuration of the gas / liquid mixing unit 35, for example, the initial foam-like fixing liquid Bu1 made of bubbles having a relatively large bubble diameter of about 0.5 to 1 [mm] is generated in a very short time. Can do. However, it is preferable that the bubble diameter is smaller when the foam-like fixing liquid Bu is used for fixing. For this reason, in the fixing device 30, the initial foam-like fixing solution Bu 1 obtained in the gas / liquid mixing unit 35 is changed to a small-diameter foam-like fixing solution Bu 2 made of bubbles having a fine bubble diameter in the bubble refining unit 38. is there.

The initial foam-like fixer Bu1 generated in the gas / liquid mixing unit 35 is supplied to the bubble refining unit 38 through the bubble transport pipe 38c. The bubble refining section 38 divides one bubble having a large diameter into two or more by applying a shearing force to the initial foam-like fixing liquid Bu1, thereby performing the bubble refining.
The bubble refining section 38 has a double cylindrical structure in which the inner cylinder 38b is included in the outer cylinder 38a, and the inner cylinder 38b is rotatable with respect to the fixed outer cylinder 38a. The initial foam-like fixing solution Bu1 is supplied to the gap between the outer cylinder 38a and the inner cylinder 38b from the location where the foam conveyance pipe 38c of the outer cylinder 38a is connected, and the foamed state is caused by the rotation of the inner cylinder 38b by passing through this gap. A shearing force is applied to the fixing liquid Bu. By applying this shearing force, one large bubble is divided into two or more fine bubbles, and the desired fine bubbles are generated while the foam-like fixing liquid Bu is passed through the gap between the outer cylinder 38a and the inner cylinder 38b. A small-diameter foam fixing solution Bu2 having a diameter is generated. The foam-like fixing liquid Bu that has passed through the gap between the outer cylinder 38a and the inner cylinder 38b and becomes the small-diameter foam-like fixing liquid Bu2 passes from the outlet provided in the outer cylinder 38a to the foam supply pipe 38d and further to the foam supply pipe. It is discharged from the bubble supply nozzle 39 at the tip of 38d to the surface of the application roller 41.
As the bubble refining portion 38 having a double cylindrical structure, a spiral groove may be provided in the inner cylinder 38b to improve the transportability of the bubble-like fixing liquid Bu in the outer cylinder 38a.

In general, in the case of a foam-like fixing solution having a bubble diameter of about 0.5 [mm] to 1 [mm] and having a large bubble that can be visually observed like the initial foam-like fixing solution Bu1, a liquid fixing solution is used. Foam can be generated relatively easily by simply stirring or the like. The foam-like fixing solution composed of such large bubbles can be generated from the liquid fixing solution in a time of several seconds or less (not taking 0.1 [second]).
Accordingly, the present inventors can easily and quickly generate a foam-like fixing liquid that is larger than a desired bubble diameter and has a size that can be visually observed. Focused on the point. Then, from a state of the foam-like fixing solution composed of large bubbles, a method for quickly generating a foam-like fixing solution composed of fine bubbles having a foam diameter of about 5 [μm] to 50 [μm] was studied. As a result, by applying shear force to the foam-like fixing solution composed of large bubbles, the desired speed can be achieved very quickly compared to the method of generating foam-like fixing solution with a fine bubble diameter by generating bubbles from the state of the liquid fixing solution. It was found that a foam-like fixing solution having a fine bubble diameter can be produced. At this time, it is considered that by applying a shearing force to the foam-like fixing solution composed of large bubbles, the large bubbles are separated into small bubbles.

  The fixing device 30 is configured by combining a gas / liquid mixing unit 35 that is a large bubble generating unit and a bubble refining unit 38. In the gas / liquid mixing part 35, the liquid fixer TL is bubbled into an initial foam-like fixer Bu1 composed of bubbles with a large bubble diameter, and in the bubble refining part 38, shear force is applied to the initial foam-like fixer Bu1. Divide all large bubbles into fine bubbles. In this way, by combining the gas / liquid mixing unit 35 and the bubble refining unit 38, the liquid fixing solution TL is made into a small-diameter foam-like fixing solution Bu2 made of bubbles having a minute bubble diameter of about 5 to 50 [μm]. Can be changed in a very short time.

  As shown in FIGS. 4 and 6, the small-diameter foam fixer Bu2 discharged from the foam supply nozzle 39 of the foam refiner 38 is supplied to the surface of the application roller 41 of the foam fixer applicator 140. As shown in FIG. 6, the foam-like fixing liquid application unit 140 includes an application roller 41 that applies the small-diameter foam-like fixing liquid Bu2 to the unfixed toner T on the transfer paper P. In addition, the foam-like fixing liquid application unit 140 includes a film thickness adjusting blade 42 that constitutes a foam-like fixing liquid film thickness control unit that controls the film thickness of the small-diameter foam-like fixing liquid Bu2 supplied on the surface of the application roller 41. Prepare. Further, the foam-like fixing liquid application unit 140 is provided with a pressure roller at a position facing the application roller 41 on the downstream side of the surface movement direction of the application roller 41 with respect to the position where the application roller 41 and the film thickness adjusting blade 42 face each other. 43.

The bulk density of the foamy fixing solution Bu is preferably in the range of 0.01 to 0.1 [g / cm ³ ]. Furthermore, in order to prevent a residual liquid feeling from occurring on the surface of the transfer paper P after the fixing solution F is applied, the bulk density of the bubbles is 0.01 [g / cm ³ ] to 0.02 [g. / Cm ³ ] is preferable. In particular, it is desired that the bulk density is at least 0.02 [g / cm ³ ] or less.
This is due to the following reason.
That is, the film thickness of the foam-like fixing liquid film Bu3 in the coating nip C where the application roller 41 applies the foam-like fixing liquid Bu to the transfer paper P is the transfer paper in order to fill the gap between the toner layers with the foam-like fixing liquid Bu. It is an essential condition that the thickness is equal to or greater than the thickness of the toner layer of the unfixed toner T on P. For this reason, the film thickness of the foam-like fixing liquid film Bu3 is preferably approximately 50 [μm] to 80 [μm]. On the other hand, in order to suppress the residual liquid feeling (wet feel) after fixing due to the application of the fixing liquid F to the surface of the transfer paper P, the adhesion amount of the fixing liquid F per unit area of the transfer paper P 0.1 [mg / cm ² ] or less is preferable. Therefore, as the bulk density of the foamed fixer ^{Bu, 0.0125 [g / cm 3} ] ~0.02 is preferably in the range of [g / cm ^3], at least 0.02 [g / cm ^3] or less It is desirable to have a density of

  The fixing liquid F only needs to be foamed when applied to a layer of resin-containing fine particles such as toner on a recording medium such as transfer paper P, and the fixing liquid container 31 (31a and 31a and 31a and 31a) is used as a fixing liquid. It does not have to be foamy within 31b). For this reason, the fixing liquid container 31 is in a liquid state that does not contain air bubbles, and is foamed at the time when the fixing liquid is supplied from the container or the liquid transport path until it is applied to the resin-containing fine particle layer. It is desirable to do. This is a foaming configuration after the fixing solution is taken out from the fixing solution container as a fixing solution, thereby reducing the transportation volume and storage volume of the fixing solution and reducing the transportation cost and storage cost. This is because it can be done.

As shown in FIGS. 4 and 6, the small-sized foam fixing liquid Bu2 having a desired foam diameter generated by the foam fixing liquid supply unit 130 is applied from the foam supply nozzle 39 provided with the foam fixing liquid supply port to the application roller. It is dripped between 41 and the film thickness adjusting blade 42 and supplied to the surface of the application roller 41. The small-diameter foamy fixing solution Bu2 supplied to the surface of the application roller 41 reaches the facing portion between the film thickness adjusting blade 42 and the application roller 41.
The film thickness adjusting blade 42 is disposed so that the tip thereof faces the surface of the coating roller 41 with a predetermined gap. Then, the small-diameter foamy fixing solution Bu2 on the surface of the application roller 41 passes through the gap between the tip of the film thickness adjustment blade 42 and the surface of the application roller 41, so that the film thickness on the surface of the application roller 41 is adjusted. The Further, in the fixing device 30, the thickness of the toner layer of the unfixed toner T on the transfer paper P is adjusted by adjusting the gap between the film thickness adjusting blade 42 and the surface of the application roller 41. Accordingly, it is possible to obtain a foam-like fixing liquid film Bu3 that is controlled to have an optimum film thickness.
Here, as the film thickness of the foam-like fixing liquid film Bu3, the foam-like fixing liquid Bu is selected according to the bubble size, the foam viscosity and the applied pressure of the small-diameter foam-like fixing liquid Bu2, and the layer thickness of the unfixed toner T. The film thickness is required to be optimized with respect to the penetration time of the unfixed toner T into the toner layer.

As shown in FIGS. 8 and 9, the film thickness adjusting blade 42 is cantilevered and rotates about the blade rotation shaft 42 a on the fixed end side to apply its own tip and coating. The gap with the roller 41 can be changed. A control unit (not shown) controls the driving of a blade rotation shaft drive motor (not shown) and rotates the blade rotation shaft 42a, thereby rotating the film thickness adjustment blade 42 and adjusting the gap.
Here, when the film thickness of the foam-like fixing liquid film Bu3 is reduced, the gap between the film thickness adjusting blade 42 and the surface of the application roller 41 is narrowed as shown in FIG. On the other hand, when the film thickness of the foam-like fixing liquid film Bu3 is increased, the gap between the film thickness adjusting blade 42 and the surface of the application roller 41 is widened as shown in FIG. Thus, by adjusting the gap between the tip of the film thickness adjusting blade 42 and the surface of the application roller 41, the film thickness of the foam-like fixing liquid film Bu3 can be controlled.
Accordingly, the penetration of the fixing liquid F into the unfixed toner layer according to the toner layer thickness of the unfixed toner T, the environmental temperature, and the like, as well as the bubble size, foam viscosity, and applied pressure of the foam-like fixing liquid Bu. The foam-like fixing liquid film Bu3 can be controlled to an optimum film thickness for adjusting the time.

  Further, the fixing device 30 controls the rotation of the film thickness adjusting blade 42 based on image information used in an optical writing device (not shown) to adjust the film thickness of the foam-like fixing liquid film Bu3. That is, for the unfixed toner T that forms the toner image transferred to the transfer paper P, a foam-like fixing liquid is used based on image information (for example, a color image or a black solid image) used in an optical writing device (not shown). A foamy fixing solution Bu with the film Bu3 adjusted in thickness is applied. Thereby, it is possible to apply the foam-like fixing liquid Bu according to the thickness of the toner layer of the unfixed toner T that forms each toner image, and fix the toner image on the transfer paper P under appropriate fixing conditions. Can do.

  As a configuration for adjusting the film thickness, the film thickness may be adjusted by a wire bar instead of the film thickness adjusting blade 42. When the film thickness is adjusted by the wire bar, the small-sized foam fixing liquid Bu2 having a desired foam diameter generated by the foam fixing liquid supply unit 130 described above is supplied from the foam supply nozzle 39 provided with the foam fixing liquid supply port. It is dropped between the application roller 41 and the wire bar. As described above, when the wire bar is used as the foam fixing solution film thickness control means, the film thickness in the axial direction on the surface of the application roller 41 can be made more uniform than the film thickness adjusting blade 42.

  A pressure roller 43 having an elastic roller portion is in contact with the application roller 41 for applying the foamy fixing liquid Bu to the transfer paper P on which the toner image is formed, thereby forming an application nip C. The transfer paper P transported from the secondary transfer nip to the fixing device 30 by the paper transport belt 29 described above is sandwiched in the coating nip C with the image surface carrying the unfixed toner image facing the coating roller 41. It is. In the application nip C, the foamy fixing liquid Bu on the application roller 41 is applied to the image surface.

Next, the principle of fixing of the fixing device 30 will be outlined.
The fixing device 30 uses a foam-like fixing solution Bu containing a softening agent that softens fine particles containing a resin by dissolving or swelling at least a part of the resin as a resin on the surface of the fixing liquid application target such as a recording medium. Apply to fine particles. Thus, a fixing method is adopted in which the resin fine particles on the surface of the fixing liquid application target are softened and the resin fine particles are fixed on the recording medium.
The toner image on the transfer paper P to which the foamy fixing liquid Bu is applied at the application nip C of the fixing device 30 is softened by the action of the applied fixing liquid F and solidifies again, whereby the toner image is transferred to the transfer paper P. It is fixed. The transfer paper P on which the toner image is fixed is discharged to the outside of the printer 100.
Needless to say, the resin fine particles described here are not particularly limited as to what they are, but they refer to toner when applied to an image forming apparatus.

Here, a fixing device using a conventional wet fixing method for applying a liquid fixing solution will be described.
Patent Document 1 describes a fixing device of a wet fixing type using an oil-in-water fixing solution in which an organic compound that can dissolve or swell toner and is insoluble or hardly soluble in water is dispersed and mixed in water. ing. In this fixing device, unfixed toner is sprayed or dripped on the surface of the fixing object disposed at a predetermined position to dissolve or swell the toner, and then the fixing object is dried. is there.

  However, the fixing device of Patent Document 1 uses an oil-in-water fixing solution in which an organic compound that is insoluble or hardly soluble in water is dispersed and mixed in water. For this reason, when a large amount of fixing liquid is applied to the unfixed toner, a recording medium (fixed object) such as transfer paper absorbs moisture of the fixing liquid, and wrinkles and curls are generated on the recording medium. As a result, the transportability of the stable and high-speed recording medium required for the image forming apparatus is significantly impaired. Therefore, if water is removed from the fixing liquid applied to the recording medium by evaporating a large amount of water contained in the fixing liquid using a drying apparatus, the power consumption of the image forming apparatus using the thermal fixing method is reduced. You will need comparable power.

In addition, several oil-based fixing solutions in which a material that dissolves or swells toner is dissolved in an oil-based solvent have been proposed as fixing solutions that do not repel water-repellent unfixed toner. As one example, for example, in Patent Document 2 described above, an aliphatic dibasic acid ester or the like as a component that dissolves or swells the resin component constituting the toner is diluted with nonvolatile dimethyl silicone as a diluent (solvent). A fixed (dissolved) fixer has been proposed.
Patent Document 3 discloses a compatibility state in which 8 to 120 parts by volume of silicone oil is mixed with 100 volumes of a solvent that dissolves toner and is compatible with silicone oil. Fixers have been proposed. As a result, the toner particles forming the unfixed toner image formed by the electrostatic method can be clearly and easily fixed on the recording medium without disturbing the image. Such an oil-based fixing solution contains an oil-based solvent having a high affinity with the water-repellent-treated unfixed toner, so that the toner is dissolved or swollen without repelling the water-repellent-treated unfixed toner, The toner can be fixed on the recording medium.

  In such a conventional wet fixing system, the fixing solution is applied to the toner image on the recording medium as a normal liquid (liquid fixing solution). For this reason, when the fixing liquid is applied to the toner image on the recording medium using a coating roller, a small amount of the fixing liquid is applied to the toner image on the recording medium and applied to the coating roller. There is a problem that it is extremely difficult to achieve both toner offset prevention. This problem will be described with reference to FIGS.

  FIG. 16 is an explanatory diagram when the film thickness of the fixing solution is thin in the liquid application fixing device 60 that applies the liquid fixing solution TL in a conventional wet fixing type fixing device. FIG. 16A is a schematic explanatory diagram of the liquid coating fixing device 60. FIG. 16B is an enlarged explanatory view in the vicinity of the coating nip where the coating roller 41 and the transfer paper P are in contact with each other in the liquid coating fixing device 60.

  In the configuration in which the liquid fixing solution TL is applied to the unfixed toner T on the transfer paper P using the application roller 41, the liquid fixing solution TL on the application roller 41 can be applied in a small amount to the transfer paper P. It is necessary to reduce the film thickness. Here, as shown in FIG. 16A, when the film thickness of the liquid fixing solution TL on the application roller 41 is made smaller than the thickness of the unfixed toner T, the result is as shown in FIG. That is, the liquid fixer TL on the application roller 41 has passed through the application position as indicated by the arrow F1 in FIG. 16B in addition to what is applied to the transfer paper P from the application roller 41 at the application nip. Some remain on the surface of the application roller 41 later. Then, at the position where the surface of the application roller 41 is separated from the transfer paper P, the surface tension generated by the liquid film of the liquid fixing liquid TL remaining on the surface of the application roller 41 (force acting in the direction of arrow F2 in FIG. 16B). ), The toner particles of the unfixed toner T on the transfer paper P are pulled. As a result, the offset toner Ta adheres to the surface of the application roller 41, and the image formed by the fixing toner layer Tb on the transfer paper P after peeling off from the application roller 41 is greatly disturbed.

Conversely, when the film thickness of the liquid fixing liquid TL on the application roller 41 is made sufficiently thicker than that of the unfixed toner T, the result is as shown in FIG. FIG. 17 is an explanatory diagram when the film thickness of the fixing solution is sufficiently thick in the liquid coating fixing device 60.
As shown in FIG. 17, at the position where the surface of the application roller 41 is separated from the transfer paper P, the liquid fixer TL has a large amount of liquid, so the surface tension due to the liquid film on the surface of the application roller 41 is the toner particles of the unfixed toner T. It becomes difficult to act on. This makes it difficult for the offset toner to adhere to the application roller 41 side. However, since a large amount of the liquid fixing solution TL is applied to the surface of the transfer paper P, the toner particles on the transfer paper P are caused to flow by the excessive liquid fixing solution TL, and the image quality is deteriorated or applied to the transfer paper P. The drying time of the liquid fixing solution TL becomes long, and a problem arises in fixing response. In addition, a sticky feeling (also referred to as tackiness) is generated on the fixed image on the transfer paper P, and therefore, when another medium such as another transfer paper P overlaps the image surface side of the transfer paper P after fixing. This causes a problem (blocking) that the toner image on the image surface sticks to the medium. When the transfer medium P is peeled off after the attachment, the toner and the medium forming the fixed image are not completely peeled off, and the fixed image may be disturbed.

Furthermore, when the liquid fixing solution TL contains water, when the amount of the liquid fixing solution TL applied to the transfer paper P containing cellulose such as paper as a recording medium is large, the transfer paper P such as paper is remarkably used. The paper curls, and there is a risk that a paper jam occurs when the recording medium is transported in an apparatus such as an image forming apparatus.
As described above, in the configuration in which the liquid fixing solution TL is applied using the application roller 41, if the amount of application of the liquid fixing solution TL is excessive, the image quality deteriorates due to the flow of toner particles, and the drying time of the liquid fixing solution TL. There is a problem that fixing responsiveness is lowered due to the increase in length. Further, depending on the material of the recording medium, there is a problem that paper jam is likely to occur. On the other hand, when a small amount of the liquid fixer TL is applied to prevent these problems, the toner particles are offset on the surface of the application roller 41 as described above. Therefore, it is possible to achieve both the application of a small amount of the fixing liquid to the toner layer on the transfer paper P and the prevention of the toner offset to the application roller 41 in order to improve the fixing response, reduce the residual liquid feeling, and prevent the curling. Extremely difficult. Even when a die coating unit, a blade coating unit, or a wire bar coating unit is used as a contact coating unit for applying a fixing solution in contact with a recording medium, when a small amount of the fixing solution is used, the toner is applied to the contact coating unit by surface tension. It adheres and image degradation occurs.

  As described above, in the configuration in which the liquid fixing liquid TL is applied by the contact application means, both a small amount of the fixing liquid applied to the toner layer on the paper and the uniform application of the toner image are not disturbed in order to improve the fixing responsiveness. It is extremely difficult to do. In addition, the problem that it is extremely difficult to achieve both the application of a small amount of the fixing solution when applying the liquid fixing solution and the uniform application without disturbing the resin fine particle layer is not limited to the toner on the recording medium. This is a problem that occurs in any case where the liquid fixer is applied to the upper fine resin particle layer.

As a fixing method capable of satisfying both the application of a small amount of fixing solution and the prevention of toner offset, Patent Document 4 discloses that the fixing solution is a foamed fixing solution in which bubbles are dispersed in the solution. A configuration in which a toner image on a recording medium is applied using an application roller is described. In this way, since the bulk density of the fixing solution can be lowered by making the fixing solution foamy, the film thickness of the fixing solution on the surface of the application roller can be increased with a smaller amount of fixing solution than before, The influence of the surface tension of the liquid on the toner particles on the recording medium can be reduced. Also, since the amount of the fixing solution is small, the residual liquid feeling on the recording medium can be suppressed, and the foam-like fixing solution is less likely to flow than the normal liquid fixing solution. It is also possible to prevent image deterioration due to the occurrence of image deterioration. Therefore, by performing fixing using a foamy fixing solution as in Patent Document 4, it is possible to fix the toner image without disturbing with a smaller amount of fixing solution applied than in the past.
The fixing device 30 of the present embodiment is also configured to apply a fixer in the form of foam to the toner layer on the recording medium, as in Patent Document 4 above.

  Further, the fixing device described in Patent Document 4 includes a foam-like fixing liquid film thickness control unit that controls the film thickness of the foam-like fixing liquid on the coating roller that is a coating member. Then, the time during which the coating roller is in contact with the recording medium and applying the foamy fixing solution to the resin fine particles on the recording medium penetrates the resin fine particle layer on the recording medium. Thus, the film thickness is controlled to be the same or longer than the permeation time to reach the recording medium. As a result, offset adhesion of resin fine particles to the application roller can be prevented, and the resin fine particles can be quickly fixed to the recording medium after the fixing liquid is applied to the recording medium carrying the resin fine particles without disturbing the resin fine particles. It becomes. Therefore, it is possible to perform fixing with excellent fixing response.

FIG. 10 is an enlarged explanatory view of a portion (application nip C) where the application roller 41 contacts the transfer paper P in the fixing device 30 of the present embodiment.
The fixing device 30 applies the fixing solution F to the transfer paper P in the form of a foam-like fixing solution Bu having a low bulk density, so that the layer of the fixing solution F is more than the toner layer on the transfer paper P even in a small amount. Can be thickened. Furthermore, by making it foam, it is possible to prevent the toner from being pulled in due to the surface tension of the fixing liquid F on the surface of the application roller 41. As a result, the toner offset to the application roller 41 can be effectively suppressed, and the occurrence of white spots due to the offset can be eliminated.

  When the average particle size of the toner particles of the unfixed toner T is about 5 to 10 [μm], in order to apply the foamy fixing liquid Bu to the unfixed toner T without disturbing the toner layer of the unfixed toner T, It is desirable that the bubble diameter range of the foam-like fixing solution Bu be about 5 to 50 [μm]. In the fixing device 30, bubbles having such a fine diameter are generated by the bubble refining in the bubble refining unit 38.

  Further, as shown in FIG. 11, the bubbles refined by the bubble refinement unit 38 are, as shown in FIG. 11, a bubble Bu-A and a liquid film boundary Bu-B that divides each bubble Bu-A (hereinafter referred to as a plateau boundary). Is).

The pressure roller 43 of the fixing device 30 uses a sponge material as an elastic layer. Here, in the application nip C, the application of the transfer paper P is performed so that the application roller 41 and the toner layer are separated after the fixing liquid F penetrates the toner layer of the unfixed toner T and reaches the transfer paper P. It is necessary to set the timing of the nip passage time.
In the fixing device 30, the passage time of the transfer paper P through the coating nip (for example, the time from when the leading edge enters the inlet of the coating nip C to when the leading edge is discharged from the outlet of the coating nip C) is set to 50 [ms] ( Msec) to 300 [ms]. Thereby, the application nip passage time of the transfer paper P is set to be equal to or longer than the permeation time of the foam-like fixing liquid Bu. In order to secure the application nip passage time of the transfer paper P in this range, a pressure roller 43 having an elastic layer made of a sponge material that can be deformed relatively large by a small change in pressure is used. The pressure roller 43 may be any material that bends (deforms along the application roller 41) when pressed by the application roller 41. For example, a material made of rubber, synthetic resin, or the like can be used, and the pressure roller 43 is not particularly limited.

The coating nip passage time (hereinafter referred to as nip time) can be calculated by a calculation formula of “nip time = (nip width) / (paper conveyance speed)”. The transfer speed of the transfer paper P can be obtained from design data of the paper transport drive mechanism.
On the other hand, the nip width can be obtained by the following method. First, a colored paint that does not dry is applied thinly on the entire surface of the application roller, and the transfer paper P is sandwiched between the application roller 41 and the pressure roller 43 facing the application roller 41 (without the roller being rotated). To attach. Then, the nip width can be obtained by measuring the length of the colored portion (usually colored in a rectangular shape) on the transfer paper P in the paper conveyance direction.
The nip time needs to be equal to or longer than the toner layer penetration time of the fixing liquid F by adjusting the nip width according to the transfer speed of the transfer paper P.

  In the fixing device 30 shown in FIG. 4, the pressure roller 43 is an elastic porous body (hereinafter referred to as a sponge), so that the application roller 41 and the pressure roller 43 of the sponge correspond to the transfer speed of the transfer paper P. It becomes easy to change the nip width by changing the inter-axis distance. An elastic rubber is also suitable instead of the sponge of the pressure roller 43, but the sponge can be deformed with a weaker force than the elastic rubber, and has a long nip width without excessively increasing the pressure applied to the application roller 41. Can be secured.

  The fixing solution F contains a softening agent that softens the resin or a swelling agent that swells. If the fixing solution F should adhere to the pressure roller 43 formed of a sponge material, the sponge material softens. There is a risk of malfunction. For this reason, the resin material of the sponge material is desirably a material that does not soften or swell against the softening agent or swelling agent. Further, the pressure roller 43 whose roller portion is made of a sponge material may have a configuration in which the roller surface is covered with a flexible film. With this configuration, even if the sponge material is a material that deteriorates with a softening agent or a swelling agent, the sponge roller is deteriorated by covering with a flexible film that does not soften or swell with the softening agent or the swelling agent. Can be prevented. As the sponge material, for example, a porous body of resin such as polyethylene, polypropylene, and polyamide is suitable. As the flexible film covering the sponge, polyethylene terephthalate, polyethylene, polypropylene, ethylene tetrafluoride / fluoroalkyl vinyl ether copolymer (PFA), metal material, and the like are suitable.

  In the fixing device 30 shown in FIG. 4, when the application roller 41 and the pressure roller 43 whose roller portion is made of sponge are always in contact, the foamy fixing solution on the application roller 41 when the transfer paper P is not being conveyed. There is a risk that Bu adheres to the pressure roller 43 of the sponge and gets dirty. For the purpose of preventing this adhesion, a paper leading edge detecting means (not shown) is provided in front of the transfer paper P being conveyed to the coating nip C, and only from the leading edge of the transfer paper P to the rear according to the paper leading edge detection signal. It is desirable to supply the foam-like fixer Bu to the application roller 41 at a timing such that the foam-like fixer Bu is applied.

  Further, in the fixing device 30, the application roller 41 and the pressure roller 43 are separated from each other during standby by a contact / separation mechanism (not shown), and the application roller 41 and the pressure roller 43 are brought into contact with each other only during application. Is desirable. In such a configuration, the contact / separation mechanism is driven from the standby state in which the application roller 41 and the pressure roller 43 are separated from each other based on the detection result of the leading edge detection of the transfer paper P by the paper leading edge detection means. The application roller 41 and the pressure roller 43 are brought into contact with each other. And based on the detection result of the trailing edge detection of the transfer paper P by the paper leading edge detection means or the detection of the trailing edge of the transfer paper P by the paper trailing edge detection means (not shown) provided separately, the contact / separation mechanism is driven, The application roller 41 and the pressure roller 43 are separated.

  As shown in FIGS. 4 and 6, the fixing device 30 includes a foam recovery device 70 that cleans the surface of the application roller 41 after passing through the application nip C. The foam recovery device 70 transfers from the transfer paper P and the residual residual foam fixer Bu4, which is the foamy fixer Bu that has not been transferred from the application roller 41 to the transfer paper P at the application nip C by the foam recovery blade 71. A small amount of offset toner Ta is removed.

FIG. 1 is an explanatory diagram of the fixing device 30 showing an outline of the foam recovery device 70.
The foam recovery device 70 includes a foam recovery blade 71, a foam recovery belt 77 that moves in the direction of arrow I in FIG. 1, a foam scraping blade 83, and a defoaming device 80.

In the coating nip C, the transfer paper P is applied to the toner image on the surface with the foamy fixing liquid Bu on the surface of the coating roller 41, pressed by the pressure roller 43, and passed through the coating nip C. Is discharged to the outside of the printer 100. Here, the foam-like fixing liquid Bu (residual foam-like fixing liquid Bu4) that has not been transferred from the application roller 41 to the transfer paper P at the application nip C remains on the surface of the application roller 41. The residual foam-like fixing liquid Bu4 contains a small amount of offset toner Ta transferred from the transfer paper P. The residual foam-like fixing liquid Bu4 and a small amount of offset toner Ta are scraped off by the foam recovery blade 71 of the foam recovery device 70 and removed from the surface of the application roller 41.
The residual foam-like fixing solution Bu4 scraped off by the foam recovery blade 71 falls on the upper surface of the foam recovery belt 77 and moves by the surface movement of the foam recovery belt 77. Thereafter, the residual foam-like fixing solution Bu4 is scraped off from the surface of the foam recovery belt 77 by the foam scraping blade 83 that comes close to or in contact with the foam recovery belt 77, and falls into the recovery container 81 of the defoaming device 80.

  In the foam recovery device 70 shown in FIG. 1, the foam scraping blade 83 is in contact with the surface movement direction of the foam recovery belt 77 in the counter direction. However, since the foam scraping blade 83 simply peels off the residual foam-like fixer Bu4 from the foam recovery belt 77, in order to reduce the load caused by the frictional resistance between the foam scraping blade 83 and the foam recovery belt 77. The foam scraping blade 83 may be brought into contact with the surface movement direction of the foam recovery belt 77 in the trailing direction.

FIG. 12 is a top view of the foam recovery belt 77 shown in FIG.
As shown in FIG. 12, on the upper surface of the foam collection belt 77, two foam guide members 73 (first foam guide members 73a for regulating the movement of the foam in the direction orthogonal to the surface movement direction of the foam collection belt 77 are provided. The second foam guide member 73b) is arranged.
The residual foam-like fixer Bu4 scraped from the application roller 41 by the foam scraping blade 83 falls on the upper surface of the foam recovery belt 77, and moves in the direction of arrow I in FIG. Moving. At this time, the movement of the residual foam-like fixing solution Bu4 in the direction (width direction) perpendicular to the surface movement direction of the foam recovery belt 77 is restricted by the first foam guide member 73a and the second foam guide member 73b, It is brought to one end. By disposing the collection container 81 below the foam collection belt 77 on the side to which the residual foam-like fixing liquid Bu4 is approached in this way, the transfer paper P that passes through the coating nip C and goes to the outside of the printer 100 is conveyed. It is possible to perform the bubble-breaking treatment of the foam-like fixing solution Bu at a position where it does not affect.

Next, the characteristic part of the defoaming apparatus 80 of this embodiment is demonstrated.
FIG. 13 is an enlarged perspective view of the defoaming device 80. As shown in FIGS. 1 and 13, the antifoaming device 80 has an antifoaming agent block 90 disposed on the inner wall surface of the collection container 81. Further, in the recovery container 81, an antifoaming liquid BL as a start liquid adjusted so that the mass of the antifoaming agent with respect to water is within 1 [%] is stored in advance.
A recovery liquid stirrer 82 is disposed in the recovery container 81. By driving the recovery liquid stirrer 82, the remaining foam-like fixing liquid Bu4 and the defoaming liquid BL that have fallen are stirred. As a result, a component as an antifoaming agent contained in the antifoaming liquid BL acts on the residual foamy fixing liquid Bu4, and the foam of the residual foamy fixing liquid Bu4 breaks up and immediately defoams. As a result, the recovered residual foam-like fixer Bu4 can be stored in the recovery container 81 in the state of the liquid fixer TL.
In the defoaming device 80, the liquid fixer TL from which the residual foamy fixer Bu4 has broken is stored in the recovery container 81 in a state of being mixed with the defoamer BL.
In addition, the amount of the antifoaming liquid BL is increased by mixing the liquid fixing liquid TL, but the antifoaming agent that forms the antifoaming agent block 90 is added to the antifoaming liquid BL as the liquid level increases due to the increase of the antifoaming liquid BL. Since it dissolves in, the concentration of the antifoaming agent in the antifoaming liquid BL can be within a certain range.

The liquid fixer TL has a volume of about 1/10 to 1/50 compared with the foam fixer Bu having the same mass. Further, since the fixing solution F used in the fixing device 30 of the present embodiment has a material composition with improved foam stability in the state of the foam-like fixing solution Bu, it is completely liquefied only by leaving the foam-like fixing solution Bu. If it takes a long time to store it in the form of bubbles, the space for storing the recovered fixing solution becomes large.
On the other hand, in the fixing device 30 of the present embodiment, the recovered fixing solution is accommodated by actively liquefying the foamy fixing solution Bu with the defoaming device 80 and storing it in the state of the liquid fixing solution TL. The space (the recovery container 81 in the fixing device 30) can be reduced in size, and the entire fixing device 30 can be reduced in size.
Further, in the defoaming device 80, since the residual foam-like fixing solution Bu4 is broken by the antifoaming agent, the foam-like fixing solution Bu can be defoamed with less energy than heating to obtain the liquid fixing solution TL. .

The defoaming liquid BL in the collection container 81 is stirred by rotating the collection liquid stirring element 82 by a magnetic stirrer. Further, the residual foam-like fixing liquid Bu4 conveyed by the foam recovery belt 77 falls into the recovery container 81, is stirred by the recovery liquid stirrer 82, and is defoamed by coming into contact with the defoaming liquid BL.
Here, as the image forming operation and the fixing operation with time, the residual foam-like fixer Bu4 continues to be sent to the recovery container 81, and as the residual foam-like fixer Bu4 is defoamed, the liquid recovered in the recovery container 81 is recovered. The integrated amount of the fixing liquid TL increases. When the integrated amount of the liquid fixing solution TL increases, the concentration of the antifoaming agent in the antifoaming solution BL decreases only with the antifoaming agent contained in the starting solution, and the defoaming effect decreases. On the other hand, in order to prevent a decrease in the concentration of the antifoaming agent, even if a high concentration antifoaming solution BL containing a large amount of antifoaming agent is used as the starting solution, the defoaming agent is not added to the offset toner or the aggregate. Adsorption reduces the defoaming effect.

  With respect to such a problem, the antifoaming device 80 according to the present embodiment attaches the antifoaming agent blocks 90 to the inner wall surface of the collection container 81 at a plurality of different heights by the antifoaming agent holder 91. Moreover, the antifoamer block 90 is a member which accommodates an antifoamer in the antifoamer accommodating member which consists of a thin layer of polyvinyl alcohol (henceforth, PVA). FIG. 14 is an enlarged explanatory diagram of the antifoaming agent holder 91.

  In the defoaming device 80, the accumulated amount of the liquid fixing solution TL collected in the collection container 81 increases with the image forming operation and the fixing operation over time. Therefore, the liquid of the defoaming solution BL containing the liquid fixing solution TL is increased. The amount increases, and the position of the liquid level of the defoaming liquid BL rises. At this time, every time the antifoaming liquid BL reaches the position of each antifoaming agent block 90, the antifoaming agent containing member of the PVA containing the antifoaming agent dissolves and the antifoaming agent is in the antifoaming liquid BL. To be added. Thereby, according to the liquid volume of the antifoam liquid BL in the collection container 81, an antifoamer can be added to an antifoam liquid in steps. The antifoaming liquid BL to which the antifoaming agent has been added is stirred by the recovery liquid stirrer 82, so that the antifoaming effect has been reduced due to a decrease in the concentration of the antifoaming agent or adsorption of the antifoaming agent to the aggregates before addition The defoaming effect of the foam liquid BL can be restored.

Like the antifoaming device 80, the antifoaming agent block 90 is attached to the inner wall surface of the collection container 81 at a plurality of locations having different heights, so that electrical control and supply for adding the antifoaming agent in stages are performed. The defoaming effect could be maintained without requiring power. As a result, it was possible to realize a defoaming apparatus that is inexpensive and compact, yet highly reliable.
The material of the defoamer-containing member is not limited to PVA, and any material that dissolves when exposed to water may be used. Furthermore, it is not limited to a material that dissolves in water, and any material that dissolves by contact with a material contained in the defoaming liquid BL may be used.

Moreover, as shown in FIG.13 and FIG.14, the defoaming apparatus 80 has five antifoamer blocks 90 from the 1st antifoamer block 90a to the 5th antifoamer block 90e in order from the downward direction of the collection container 81. FIG. It is arranged.
As these five antifoaming agent blocks 90, it is preferable to increase the amount of antifoaming agent accommodated in an antifoaming agent accommodation member as the antifoaming agent block 90 arrange | positioned upwards. This is because the amount of the antifoaming liquid BL when the antifoaming agent is added increases as the antifoaming agent block 90 arranged at the upper side, and in order to maintain the concentration of the antifoaming agent, more antifoaming agent Is necessary.

Further, the fixing solution F used in the fixing device 30 of the present embodiment includes constituent materials such as a softening agent, a solubilizing agent, a foaming agent, a foaming agent, a water-soluble resin, and a diluent, and these have excellent safety. Material. In addition, offset toner is mixed, but the content is small. For this reason, there is no safety problem even if the liquid fixing solution TL obtained by collecting and breaking the bubbles in the state of the foamy fixing solution Bu is discarded as it is.
However, considering the environmental load, it is desirable to separate and collect about 92% moisture and the above-mentioned constituent materials. It has been found that it is effective to use aluminum sulfate, which is generally used as an aggregating agent, as an antifoaming agent for breaking the foamed fixing solution Bu against such problems.
By using aluminum sulfate having such a function as an aggregating agent as an antifoaming agent, when the liquid fixing solution TL and the antifoaming solution BL are mixed, the constituent material contained in the liquid fixing solution TL forms a salt. And separated from moisture.
The environmental load can be reduced by discarding the antifoaming liquid BL containing the liquid fixing liquid TL after the salt separated from the water is recovered by filtration or the like.

Further, when an antifoaming agent having an action as an aggregating agent is used, the foam is erased in a short time, but the antifoaming liquid BL containing the fixing liquid accumulated in the collection container 81 becomes cloudy and the toner is mixed. It was a grayish white cloudy state.
The problem caused by them is that the antifoaming agent is adsorbed on the mixed toner, white turbid particles, etc. and the concentration of the antifoaming agent is lowered. With respect to such a problem, the antifoaming device 80 adds the antifoaming agent step by step, so even if the concentration of the antifoaming agent decreases with time, the antifoaming performance is improved by the newly added antifoaming agent. Can be restored.

Moreover, as a structure which adds an antifoamer regularly, the structure provided with the concentration sensor and the dripping apparatus which supplies a proper density | concentration can be considered. However, the configuration including the concentration sensor and the dropping device leads to an increase in size and complexity of the defoaming device, and causes many problems such as cost and reliability.
On the other hand, in the defoaming device 80, the defoamer blocks 90 are attached to the inner wall surface of the collection container 81 at a plurality of different heights, and the defoaming liquid BL in the collection container 81 is added to each defoamer block 90. When it reaches the height, the antifoaming agent is added to the antifoaming liquid BL. Thereby, the antifoaming agent can be gradually added to the antifoaming liquid BL as the liquid level of the antifoaming liquid BL in the collection container 81 increases with the image forming operation and the fixing operation with time. Thereby, the defoaming effect by an antifoamer can be maintained, without adding a concentration sensor and a dripping apparatus newly. In addition, the antifoaming agent block 90 provided in the antifoaming device 80 includes an appropriate amount of antifoaming agent such as PVA in a thin layer, and the antifoaming agent containing member is contained by water contained in the liquid in the collection container 81. The antifoaming effect is restored by dissolving and mixing.

  In the fixing device 30 of the present embodiment, the transfer paper P that has passed through the coating nip C is discharged out of the printer 100, but the transfer paper P is transferred to the transfer path of the transfer paper P from the coating nip C toward the outside of the printer 100. A pair of smooth rollers (hard rollers) for holding and conveying the paper P may be provided. The transfer paper P carrying the softened toner layer coated with the fixing liquid when passing through the coating nip C is held and pressed by a pair of smoothing rollers, thereby smoothing the surface of the toner layer and glossing the toner image. Can be granted. Furthermore, the soft toner layer can be pushed into the transfer paper P by being held by the smooth roller, and the fixability of the toner layer to the transfer paper P can be improved.

FIG. 15 is a schematic configuration diagram of another example of the fixing device 30 to which the present invention is applied.
A fixing device 30 shown in FIG. 15 includes a pressure belt 430 instead of the pressure roller 43 provided in the fixing device 30 shown in FIG. As the pressure belt 430, for example, a member such as a seamless nickel belt, a seamless PET file, or the like coated with a releasable fluororesin such as PFA is used.

  Similar to the fixing device 30 described with reference to FIG. 4, the foamy fixing solution supply unit 130 of the fixing device 30 illustrated in FIG. 15 includes a gas / liquid mixing unit 35 that generates the initial foaming fixing solution Bu1, and an initial bubble. And a bubble refining section 38 for generating a small-diameter foam-like fixer Bu2 by separating the fixer Bu1 with a shearing force. Then, the foam-like fixing liquid Bu generated by the foam-like fixing liquid supply unit 130 is supplied from the foam supply nozzle 39 to the surface of the application roller 41. On the other hand, a control unit (not shown) adjusts the gap between the film thickness adjustment blade 42 and the surface of the application roller 41 by controlling the driving of a blade rotation shaft drive motor (not shown). As a result, the foam-like fixing liquid Bu supplied to the surface of the application roller 41 passes through this gap and is supplied to the application nip C as a foam-like fixing liquid film Bu3 having an optimum film thickness.

In a configuration in which a belt is used as a member for forming the coating nip C as in the fixing device 30 shown in FIG. 15, the nip width can be easily increased. Therefore, the configuration using the belt as the member forming the application nip C is not limited to the configuration using the belt member as the pressure member as shown in FIG. 15, and a belt-shaped application member is used instead of the application roller 41. The pressure member may be a roller-shaped member.
Thus, by using at least one of the application member and the pressure member as a belt-like member, it becomes possible to easily widen the nip width and apply an excessive force that causes wrinkles on the paper. If the nip time is the same, the paper conveyance speed can be increased, and high-speed fixing is possible.

  In the fixing device 30 of the present embodiment, the softening agent liquid 310a and the foaming agent liquid 310b constituting the liquid fixing liquid TL are stored independently, but the present invention is not limited to this. The liquid fixing solution TL containing the softening agent and the foaming agent may be stored in the fixing solution container 31 and the foamed fixing solution Bu may be generated from the liquid fixing solution TL by the foamed fixing solution generating means. Good. In the configuration in which the liquid fixer TL is stored, a fixer preparation means for preparing a fixer by mixing a plurality of fixer component liquids is not necessary, so that the configuration of the apparatus can be simplified.

  Next, the composition of the fixing solution F will be described. The fixing solution F used in the fixing device 30 contains at least a softening agent and a foaming agent.

First, the softener will be described.
The softening agent has a function of softening the resin fine particles by dissolving or swelling at least a part of the resin contained in the toner.
The softener is preferably an ester compound. The ester compound is excellent in solubility or swelling property that dissolves or swells at least a part of the resin contained in resin fine particles such as toner. Among the ester compounds, aliphatic esters and carbonates are particularly preferable because of their excellent resin softening ability. Moreover, it is preferable also from the point which does not inhibit the foaming property by the anionic surfactant as a foaming agent mentioned later.

  Further, the fixing of the toner as the resin fine particles to the recording medium is performed by an apparatus frequently used in a sealed environment, and the softening agent remains in the toner even after the toner is fixed on the recording medium. It is preferable that the toner is not fixed with volatile organic compounds (VOC) and unpleasant odor. That is, the softener preferably does not contain volatile organic compounds (VOC) and substances that cause unpleasant odors. 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.).

  As a practical odor measurement scale that can measure odors in office environments with high accuracy, the odor index [10 × log (until the substance odor is no longer felt) by the three-point comparison odor bag method, which is a sensory measurement The dilution ratio of the substance)] can be used. 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.

  The aliphatic ester includes a saturated aliphatic ester. When the aliphatic ester contains a saturated aliphatic ester, the storage stability (resistance to oxidation, hydrolysis, etc.) of the softener can be improved. Further, many saturated aliphatic esters can dissolve or swell the resin contained in the toner within 1 [second]. Furthermore, the saturated aliphatic ester can reduce the stickiness of the toner provided on the recording medium. This is considered to be because the saturated aliphatic ester forms an oil film on the surface of the dissolved or swollen toner.

  Therefore, as the fixing solution, it is desirable to use a solution in which the saturated aliphatic ester contains a compound represented by the general formula “R1COOR2”. R1 in the general formula of this compound represents an alkyl group having 11 to 14 carbon atoms, and R2 represents 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, an odor is generated. As the fixing solution, the saturated aliphatic ester containing a compound represented by the general formula “R1COOR2” can improve the solubility or swelling property with respect to the resin contained in the toner. Further, the odor index of the compound represented by the general formula “R1COOR2” is 10 or less, and does not have an unpleasant odor or an irritating odor.

Examples of the aliphatic monocarboxylic acid ester including the compound represented by the general formula “R1COOR2” include ethyl laurate, hexyl laurate, ethyl tridecylate, isopropyl tridecylate, ethyl myristate, isopropyl myristate, and the like. It is done. Many of these aliphatic monocarboxylic esters containing the above compounds are soluble in oily solvents but not in water. Therefore, for many of the aliphatic monocarboxylic acid esters containing the above compounds, in an aqueous solvent, glycols are contained in the fixing solution as a dissolution aid, and are in the form of dissolution or microemulsion.
Oiliness in this embodiment means the property that the solubility with respect to water in room temperature (20 [degreeC]) is 0.1 [w%] or less.

  In order to suppress hydrolysis when the saturated aliphatic ester is used, at least one of “R1COOH” and “R2OH” which are hydrolysates of the compound represented by the general formula “R1COOR2” described above. By containing in the fixing solution, the decomposition of the softening agent can be suppressed. Examples of the hydrolyzate include lauric acid, dodecylic acid, myristic acid, myristic acid, methanol, ethanol, and isopropyl alcohol. The content is not particularly limited, but the content of the carboxylic acid compound is such that the pH of the fixing solution does not become 7 or less, and the content of the alcohol compound ranges from 1 [wt%] to 30 [wt%]. Is appropriate. Exceeding these contents is not suitable because the foaming property of the fixing solution deteriorates.

  Further, as the fixing solution, it is desirable to use a solution in which the aliphatic ester contains an aliphatic dicarboxylic acid ester. When the aliphatic ester contains 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 preferable that the time until the toner is fixed on the recording medium after applying the fixing liquid to the unfixed toner on the recording medium is within 1 [second]. When the aliphatic ester contains an aliphatic dicarboxylic acid ester, a time required for fixing the toner on the recording medium by applying a fixing solution to the unfixed toner or the like on the recording medium is 0.1 [second. ] Within. 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 solution can be reduced.

Therefore, as the fixing solution, it is desirable to use a fixing liquid containing the compound represented by the general formula “R3 (COOR4) ₂ ”. R3 in the general formula of this compound represents an alkylene group having 3 to 8 carbon atoms, and R4 represents a linear or branched alkyl group having 3 to 5 carbon atoms. If the number of carbon atoms in R3 and R4 is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability decreases. As the fixing solution, the aliphatic dicarboxylic acid ester containing a compound represented by the general formula “R3 (COOR4) ₂ ” is used to improve the solubility or swellability of the resin contained in the toner. Can do. In addition, the odor index of the compound represented by the general formula of “R3 (COOR4) ₂ ” is 10 or less, and does not have an unpleasant odor or an irritating odor.

Examples of the aliphatic dicarboxylic acid ester containing a compound represented by the general formula “R3 (COOR4) ₂ ” include, for example, 2-ethylhexyl succinate, dibutyl adipate, diisobutyl adipate, diisopropyl adipate, diisodecyl adipate, sebacic acid Examples include diethyl and dibutyl sebacate. Many of these aliphatic dicarboxylic acid esters containing 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 dissolved or in the form of a microemulsion.

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

As the fixing solution, it is preferable to use a fixing solution containing a compound represented by the general formula “R5 (COOR 6 —O—R 7) ₂ ” as described above. R5 in the general formula of this compound represents an alkylene group having 2 to 8 carbon atoms, R6 represents an alkylene group having 2 to 4 carbon atoms, and R7 represents 1 to 4 carbon atoms. The alkyl group is shown. If the number of carbon atoms in R5, R6, and R7 is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability decreases. As the fixing solution, a solution in which the aliphatic dicarboxylate dialkoxyalkyl contains a compound represented by the general formula “R5 (COOR6-O-R7) ₂ ” is used. Swellability can be improved. Moreover, the odor index of the compound represented by the general formula “R5 (COOR6-O-R7) ₂ ” is 10 or less, and does not have an unpleasant odor or an irritating odor.

  Examples of the aliphatic dicarboxylate dialkoxyalkyl containing the above compound include diethoxyethyl succinate, dibutoxyethyl succinate, dicarbitol succinate, dimethoxyethyl adipate, diethoxyethyl adipate, dibutoxyethyl adipate, sebacin Examples include diethoxyethyl acid. When these aliphatic dicarboxylic acid dialkoxyalkyls containing the above compounds are used in an aqueous solvent, glycols are included in the fixing solution as a solubilizing agent, if necessary, to form a solution or microemulsion.

  Although not the fatty acid ester, examples of the carbonate ester include ethylene carbonate, propylene carbonate (propylene carbonate), glycerol 1,2-carbonate, 4-methoxymethyl-1,3-dioxolan-2-one and the like as a softening agent. Can be used.

  Examples of ester compounds other than the above include citric acid esters such as triethyl citrate, acetyl triethyl citrate, tributyl citrate and tributyl acetyl citrate; ethylene glycol diacetate, diethylene glycol diacetate, triethylene glycol diacetate And compounds obtained by esterifying glycols such as monoacetin; compounds obtained by esterifying glycerol such as monoacetin, diacetin, and triacetin.

  The content of the softening agent in the liquid fixing solution TL is preferably 0.5 [wt%] to 50 [wt%], and more preferably 5 [wt%] to 40 [wt%]. When the content of the softening agent is less than 0.5 [wt%], the effect of dissolving or swelling the resin contained in the toner may be insufficient, and when it exceeds 50 [wt%] There is a possibility that the fluidity of the resin contained in the toner cannot be lowered over time, and the fixing toner layer has adhesiveness.

Next, the dissolution aid contained in the liquid fixing solution TL will be described.
When the concentration of the softening agent in the fixing liquid F increases, the softening agent may be difficult to dissolve in water as a dilution solvent. Therefore, polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butylene glycol, glycerin and the like are used as dissolution aids. It was found that the inclusion in the fixing solution F dissolves the softener even at a high concentration and does not deteriorate the foaming property due to the fatty acid salt, but rather the foaming property is improved. The content of the polyhydric alcohol in the fixing solution F is preferably in the range of 1 [wt%] to 30 [wt%]. When the content of the polyhydric alcohol exceeds 30 [wt%], the foamability is rather deteriorated, which is not suitable.

Next, the foaming agent will be described.
Anionic surfactants can realize excellent foaming properties and foam stability, and are excellent as foaming agents. Among these anionic surfactants, fatty acid salts are most excellent in foam stability and are most suitable as a foaming agent for fixing solutions. On the other hand, softeners generally have a strong antifoaming effect. For this reason, when the liquid fixing solution TL is used as the foamy fixing solution Bu as in the fixing device 30 of the present embodiment, the higher the concentration of the softening agent in the fixing solution F, the higher the foamability and foam of the fixing solution F. There is a possibility that the foam stability of the foam-like fixing solution Bu is deteriorated and it is difficult to foam, or the foam-like fixing solution Bu is likely to break. If the foam fixing solution Bu having a low bulk density cannot be obtained if foaming is difficult and the foam fixing solution Bu having a desired bulk density is obtained, it is applied if the foam fixing solution Bu easily breaks. The bubbles are completely broken at the nip C, and the same problem as in the configuration in which the liquid fixer TL is applied occurs.

  Here, foam stability refers to the property that the fixing solution in the form of foam is difficult to become liquid. The foam-like fixing liquid Bu to be applied to the unfixed toner by the fixing device 30 of the present embodiment has foam stability that does not defoam even if left in a foam state for 1 minute and can maintain the foam state. Is desirable.

  In order to solve the problem of foaming deterioration when the concentration of the softening agent in the fixing solution is increased, the present inventors have made various prototypes based on the type and concentration of the anionic surfactant. Further, a prototype was made by paying attention to a technique called “super fat” described in Non-Patent Document 1, that is, a free fatty acid contained in a solid detergent (soap). Here, to outline the technology called super fat, it is a method of adding a small amount of free fatty acids that are difficult to oxidize to increase the excess fat and oil, leaving a small amount of fat and oil that is not saponified, for example, to enhance the moisturizing action, etc. It is said to be effective. In Non-Patent Document 1, it is known that when a very small amount of fatty acid is added to a soap water-based system, the foaming performance is improved and the foam quality becomes more creamy, which is called super fat soap. It is described. Similar to this super fat, an attempt was made to foam by adding a very small amount of fatty acid to a fixing solution having a softening agent, but both foamability and foam stability were poor.

On the other hand, the present inventors use a fatty acid salt having 12 to 18 carbon atoms as a foaming agent, and further contain a fatty acid having 12 to 18 carbon atoms in the fixing solution, thereby increasing the concentration of the softening agent. The present inventors have found that it is possible to provide a foamy fixing solution that does not deteriorate the foamability of the fixing solution.
Here, in the fixing solution containing a softening agent, a solution containing an anionic surfactant and a fatty acid salt (12 to 18 carbon atoms) is more foamable than when foaming water. Is excellent. Specifically, laurate (12 carbon atoms), myristate (14 carbon atoms), palmitate (16 carbon atoms), and stearate (18 carbon atoms) are suitable.
Further, pentadecylic acid (carbon number 15), margaric acid (carbon number 17), and the like are also suitable.

  Here, the action of the fatty acid and the softening agent will be described. The softening agent has an ester group in the chemical structure, and the fatty acid has a carbonyl group in the chemical structure. From this point, the ester group of the softener and the carbonyl group of the fatty acid show an electrical action in the fixing solution system, and this causes a binding action between molecules, and the fixing solution has foaming properties. And foam stability is improved.

  Even in the range of 12 to 18 carbon atoms of the fatty acid salt, the smaller the number of carbons, the better the foaming property, but the foam stability is poor, and the higher the number of carbons, the less foamable, the foam stability. It is extremely excellent. Therefore, the fatty acid salt in the fixing solution may be a single fatty acid salt, but a more excellent fixing solution is obtained by mixing a fatty acid salt having 12 to 18 carbon atoms. As a mixing ratio, it is desirable to contain the most myristic acid salt (14 carbon atoms) and to lower the ratio of lauric acid salt (12 carbon atoms) and stearic acid salt. More specific fatty acid salt ratios are 0: 6: 3: 1, 1: 5: 3: 1, or 1 in terms of mass ratio of laurate: myristate: palmitate: stearate : 4: 4: 1 is suitable.

  The content of the anionic surfactant in the liquid fixing solution TL is preferably 0.1 [wt%] to 20 [wt%], and more preferably 0.5 [wt%] to 10 [wt%]. If the content of the anionic surfactant in the liquid fixing solution TL is less than 0.1 [wt%], foaming may be insufficient, and the liquid fixing of the anionic surfactant may be performed. When the content in the liquid TL exceeds 20 [wt%], the viscosity of the fixing liquid increases and the foamability may be reduced.

By containing a fatty acid having the same number of carbon atoms as the foaming agent fatty acid salt in the fixing solution, foamability and foam stability can be maintained even when the concentration of the softening agent is increased. If the concentration of the softening agent in the fixing solution is less than 10 [wt%], there is no problem in foaming properties even if no fatty acid is contained. However, when the concentration of the softening agent in the fixing solution is 10 [wt%] or more, particularly 30 [wt%] or more, the fatty acid salt alone hardly causes foaming and the foaming properties deteriorate. In the case where the content of the softening agent in the fixing solution is 30 [wt%], the foamability can be maintained by containing a fatty acid having the same carbon number as the fatty acid salt.
However, if the content of fatty acid in the fixing solution is too large, the ratio of the fatty acid salt that is a foaming agent is lowered, and the foamability is deteriorated again. Therefore, it is better to make the number of moles of fatty acid salt the same as or larger than the number of moles of fatty acid. Or when the ratio of a fatty acid and a fatty acid salt is in the range of 5: 5 to 1: 9, the foamability is excellent.

  In addition to the combination of fatty acid and fatty acid salt of the same carbon number, for example, the fatty acid salt is a combination of amine myristate and fatty acid is stearic acid, the fatty acid salt is potassium palmitate and the fatty acid is a combination of stearic acid, Combinations different in the range of 12 to 18 carbon atoms may be used. In short, by containing a fatty acid having a carbon number of 12 to 18 in the fixing solution, even if a high concentration softener is contained, the foamability is not deteriorated, the foam stability is excellent, and the bulk density is extremely high. Allows low foaming.

  In addition, even if the fixing solution contains a fatty acid having 12 to 18 carbon atoms using another anionic surfactant, for example, alkyl ether sulfate (AES) as a foaming agent, the foaming property due to an increase in the softener concentration. It has been found that there is an effect of preventing the deterioration. However, the best combination is a combination with a fatty acid salt.

  Furthermore, fatty acid sodium salts, fatty acid potassium salts, and fatty acid amine salts are suitable as the fatty acid salts. Furthermore, the most suitable fatty acid amine is specifically prepared by heating water, adding a fatty acid, then adding triethanolamine, and heating to saponify for a certain period of time. Can do. At this time, by increasing the molar ratio of fatty acid to triethanolamine in the range of 1: 0.5 to 1: 0.9 and the fatty acid ratio, unreacted fatty acid remains after saponification reaction, and fixing Fatty acid and fatty acid amine salt can be mixed in the liquid. The same is possible with sodium and potassium salts.

  In the fixing solution, 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. Further, the above-described saturated fatty acid salt and unsaturated fatty acid salt may be mixed and used as a foaming agent.

  In the foam-like fixing liquid Bu, if the foam-like fixing liquid Bu breaks before reaching the coating nip C, a problem similar to the configuration in which the liquid fixing liquid TL is applied occurs. Accordingly, there is a demand for a foam having excellent foam stability such that the generated foam-like fixing solution Bu can reach the coating nip C in a foam state. 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.

Next, the solvent contained in the liquid fixing solution TL will be described.
As the solvent, water, an aqueous solvent obtained by adding alcohol or the like to water, and the like are preferable.
As water, for example, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used.
When the aqueous solvent is used, it is preferable that the surface tension is 20 [mN / m] to 30 [mN / m] by adding a surfactant. As the above alcohols, for example, monohydric alcohols such as cetanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol, and the like from the advantage of improving the stability of bubbles in the foamed fixing solution Bu and making it difficult to break the bubbles. Polyhydric alcohols such as propylene glycol, tripropylene glycol, 1,3-butylene glycol and glycerin are preferred. Further, containing these unit price or polyhydric alcohols has an effect of preventing curling of a medium such as paper.

  In addition, a configuration in which an O / W emulsion or a W / O emulsion is formed by containing an oily component in the fixing solution to improve permeability and prevent curling of a medium such as paper is also desirable. In that case, as specific dispersants, 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. .

  In addition, as a method for dissolving or dispersing the microemulsifier in the fixing solution, for example, a mechanical stirring means such as a homomixer or a homogenizer using a rotary blade, or a means for applying vibration such as an ultrasonic homogenizer Is mentioned. In any case, the softener is dissolved or dispersed in the microemulsion by applying a strong shear stress to the liquid fixing solution TL.

The resin fine particles used in the present embodiment are toners, but the resin fine particles containing a resin to be fixed are not limited to toner, and any fine particles containing a resin may be used. For example, a conductive member Resin fine particles containing may be used. Of the resin fine particles, 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, a binder resin, and a release agent, and further contains other components as necessary. There is no restriction | limiting in particular as said binder resin which the said toner contains, According to the objective, it can select suitably, For example, a polystyrene resin, a styrene-acryl copolymer, a polyester resin etc. are mentioned. The releasing agent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include wax components such as carbanau wax and polyethylene. Moreover, there is no restriction | limiting in particular as said coloring agent, According to the objective, it can select suitably from well-known dyes and pigments.

The charge control agent contained in the toner is not particularly limited and may be appropriately selected from known ones according to the purpose. Examples thereof include triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes. , Alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine activators, metal salts of salicylic acid, salicylic acid derivatives Examples thereof include metal salts. These may be used individually by 1 type and may use 2 or more types together.
The other components contained in the toner are not particularly limited and may be appropriately selected depending on the intended purpose. For example, external additives, fluidity improvers, cleaning improvers, magnetic materials, metals Soap and the like.
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.

  Further, it is desirable that the foamy fixing solution Bu 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 desirable that the foam-like fixer Bu in which the fixer becomes foamy 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 surface of hydrophobic silica and hydrophobic titanium oxide, and is approximately 20 [mN / M] surface energy. Actually, since the entire surface of the water-repellent treated toner is not completely covered with the hydrophobic fine particles, the surface energy of the water-repellent treated toner is approximately 20 [mN / m] to 30 [mN]. / M]. Therefore, the surface tension of the foam-like fixing liquid Bu is 20 [mN / m] to 30 [mN / m] in order to have an affinity for the water-repellent toner (having sufficient wettability). Is preferred.

In the present embodiment, the transfer paper P is used as a recording medium to which the fixing liquid is applied. However, the recording medium is not limited to paper, and any of metal, resin, ceramics, and the like may be used. However, the fixer application target is preferably permeable to the fixer, and if the substrate to which the fixer is to be applied is not liquid permeable, it is a fixer application target having a liquid permeable layer on the substrate. It is preferable.
The form of the medium is not limited to a sheet shape, and may be a three-dimensional object having a flat surface or a curved surface.
Further, the present invention can also be applied to applications in which transparent resin fine particles are uniformly fixed on a medium such as paper to protect the medium surface (so-called varnish coating).
Among the above media, the recording medium is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include paper, cloth, and a plastic film such as an OHP sheet having a liquid permeable layer. .

[Experimental example]
Next, an experimental example in which the fixing property of the fixing device 30 to which the present invention is applied has been confirmed will be described.
Hereinafter, a method for adjusting the fixing solution used in this experimental example will be described.

<Preparation of fatty acid triethanolamine salt>
First, the manufacturing method of the fatty acid triethanolamine salt which a foaming agent liquid contains is demonstrated.
When the weight percent of the total fatty acid triethanolamine salt is 100 [wt%], 35.1 [wt%] of myristic acid (Kanto Chemical Reagent), which is a fatty acid, and 26.3 of palmitic acid (Kanto Chemical Reagent). [Wt%], stearic acid (Kanto Chemical Reagent) is measured to 8.8 [wt%], and triethanolamine as a neutralizing agent is measured to 29.8 [wt%]. These are stirred in ion-exchanged water at a liquid temperature of 80 [° C.] for 30 minutes with a stirrer (100 [rpm]), and then naturally cooled to room temperature to obtain a fatty acid triethanolamine salt. This is used for the foaming agent liquid described below.

<Adjustment of foaming agent liquid and softener liquid (1)>
Hereinafter, the first combination of the foaming agent liquid and the softening agent liquid used in this experimental example will be described.
As the liquid containing foaming agent (foaming agent liquid 310b), when the weight percentage of the entire foaming agent liquid 310b is 100 [wt%], the fatty acid triethanolamine salt (fatty acid TEA salt) is 6 0.7 [wt%], 0.8 [wt%] palm fatty acid diethanolamide (1: 1) type (Matsumoto Yushi, Marpon MM), which is a foam enhancer, and 92.5 [wt%] ion-exchanged water, These are liquids obtained by mixing with an ultrasonic homogenizer for 3 minutes in advance. The obtained foaming agent liquid 310b is a bottle container (foaming agent liquid container 31b) made of PET (polyethylene terephthalate) resin when 60 [wt%] of the entire liquid fixing solution TL is 100 [wt%]. ).
Further, as the liquid containing the softener (softener liquid 310a), propylene carbonate (manufactured by Kanto Chemical Reagents Co., Ltd .: hereinafter also referred to as PC) is used, and the entire liquid fixing liquid TL is 100 [wt%]. 40 [wt%] was put in a bottle container (softener liquid container 31a) made of PET resin.

<Adjustment of foaming agent liquid and softener liquid (2)>
Next, the second combination of the foaming agent liquid and the softening agent liquid used in this experimental example will be described.
As a liquid (foaming agent liquid 310b) containing a foaming agent, fatty acid triethanolamine salt (fatty acid TEA salt) is used when the weight percentage of the entire foaming agent liquid 310b is 100 [wt%]. 5 [wt%], 0.6 [wt%] of coconut fatty acid diethanolamide (1: 1) type (Matsumoto Yushi, Marpon MM), which is a foam increasing agent, and 94.9 [wt%] of ion-exchanged water Is a liquid obtained by previously stirring and mixing for 3 minutes with an ultrasonic homogenizer. The obtained foaming agent liquid 310b is a bottle container (foaming agent liquid container 31b) made of PET (polyethylene terephthalate) resin when 90 [wt%] of the entire liquid fixing solution TL is 100 [wt%]. ).
Further, as the liquid containing the softening agent (softening agent liquid 310a), diethoxyethyl succinate (Croda Corporation, Claude DES: hereinafter also referred to as DES) is used, and the entire liquid fixer TL is 100 wt%. As 10 [wt%] was put in a bottle container (softener liquid container 31a) made of PET resin.

The above-described softening agent liquid 310a and the foaming agent liquid 310b are mixed to form a liquid fixing liquid TL, and the foaming fixing liquid supply unit 130 that further uses the foaming fixing liquid Bu has the structure shown in FIG. It was.
The foam-like fixing liquid supply unit 130 used in this experimental example includes two bottles (softener liquid container 31a and foaming liquid container 31b) made of PET resin, and liquid transport pumps 33 (33a, 33b). As a tube pump (tube inner diameter 2 [mm], tube material: silicone rubber). In addition, the liquid conveyance flow path (softener liquid conveyance pipe 34a, foaming agent liquid conveyance pipe 34b, liquid fixer liquid conveyance pipe 340 and foam conveyance pipe 38c) connecting each member is a silicone rubber tube having an inner diameter of 2 [mm]. It is. The microporous sheet 37 for generating the initial foam-like fixing liquid Bu1 in a state larger than the desired foam diameter disposed in the gas / liquid mixing unit 35 is a stainless mesh sheet (opening of about 40 [μm]). It is the composition. The foam-like fixing liquid supply unit 130 constitutes a large bubble generation unit by the two bottles, the tube pump, the liquid transport channel, and the gas / liquid mixing unit 35 described above.

  In addition, the bubble refining unit 38 of the foam-like fixing solution supply unit 130 generates a small-sized foam-like fixing solution Bu2 having a desired bubble diameter from the initial foam-like fixing solution Bu1 generated by the large bubble generating unit described above. In the bubble refining unit 38, an inner cylinder 38b fixed to a fixed shaft is rotated by a rotation drive motor (not shown). The material of the outer cylinder 38a and the inner cylinder 38b constituting the double cylinder structure was PET resin. The inner diameter d1 of the outer cylinder 38a is 10 [mm], the inner length L1 of the outer cylinder 38a is 120 [mm], the outer diameter d2 of the inner cylinder 38b is 8 [mm], and the length L2 of the inner cylinder 38b is 100 [mm]. mm]. The rotation speed of the inner cylinder 38b was 300 [rpm], and the rotation time was 10 seconds.

As the foam-like fixer application unit 140 for applying the foam-like fixer Bu generated by the foam-like fixer supply unit 130 to the transfer paper P, the one having the configuration shown in FIGS. 1, 6 and 7 was used.
A configuration in which the foam-like fixing liquid Bu generated by the above-described foam-like fixing liquid supply unit 130 is supplied to the surface on the upstream side in the surface movement direction of the coating roller 41 with respect to the gap between the tip of the film thickness adjusting blade 42 and the coating roller 41. It is. The gap between the tip of the film thickness adjusting blade 42 and the surface of the coating roller 41 was set to 40 [μm].
The pressure roller 43 is a sponge roller formed of a polyurethane foam material (product name “Color Foam EMO”, manufactured by INOAC) having an aluminum alloy roller (φ10 [mm]) as a core and an outer diameter of φ50 [mm].
The application roller 41 is a SUS (stainless steel) roller (φ30 [mm]) that is baked and coated with PFA (tetrafluoroethylene / fluoroalkyl vinyl ether copolymer) resin.
The film thickness adjusting blade 42 is obtained by adhering a flat glass having a thickness of 1 [mm] to an aluminum alloy support plate. The gap between the coating roller 41 and the glass surface can be controlled.
The paper conveyance speed is 150 [mm / s].

In the application nip C of the fixing device 30, the transfer paper P is conveyed by the surface movement of the application roller 41 and the pressure roller 43. At that time, on the surface of the application roller 41 that has passed through the application nip C, there is a residual foam-like fixer Bu4 that has not moved to the transfer paper P, and a small amount of offset toner Ta is mixed. is there.
As shown in FIG. 1, the fixing device 30 used in this experimental example includes a foam recovery device 70 that recovers the residual foam fixing solution Bu4 from the coating roller 41, and the residual foam fixing solution recovered by the foam recovery device 70. Bu4 is collected in the collection container 81 of the defoaming device 80. In the foam recovery device 70 shown in FIG. 1, the foam scraping blade 83 is in contact with the foam recovery belt 77 in the counter direction, but in this experimental example, it is arranged in contact with the trailing direction. When the driving of the fixing device 30 is stopped, the foam recovery belt 77 recovers from the application roller 41 and conveys the residual foam-like fixing liquid Bu4 remaining around the foam recovery blade 71 and the foam recovery belt 77 to the recovery container 81. Continue driving until stop.

  Details of the conditions of Examples 1 to 4 and Comparative Examples 1 and 2 of this experimental example will be described later, and the experimental results are shown in Table 1.

  Next, conditions of each embodiment of the apparatus to which the present invention is applied and comparative examples of apparatuses different from those to which the present invention is applied will be described.

[Example 1]
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 30 [μm].
In the foam-like fixing solution supply unit 130, a PC-based fixing solution is prepared based on the above “adjustment of the foaming agent solution and the softening agent solution (1)”, and the gas / liquid mixing unit 35 and the bubble refining unit 38 A foamy fixer Bu was produced. Transfer foam on which unfixed toner T is formed in the coating nip C is formed by using the foam-like fixer Bu as a foam-like fixer film Bu3 having a thickness of about 100 [μm] on the application roller 41 of the foam-type fixer application unit 140. It was applied on P.

  In Example 1, aluminum sulfate (sulfate band) generally used as a flocculant was used as the antifoaming agent. A defoaming liquid BL made of a 0.8 [%] aqueous solution of aluminum sulfate as a start liquid is previously stored in a collection container 81 having a capacity of 1.5 [L], and the antifoaming liquid 82 is collected by a recovery liquid stirrer 82. Stir BL. Furthermore, an antifoaming agent block 90 formed by encapsulating aluminum sulfate as an antifoaming agent with a thin layer of PVA is disposed on the inner wall surface in the collection container 81 using an antifoaming agent holder 91. In the first embodiment, when 300 [mL] of the start liquid is put in the recovery container 81 having a capacity of 1.5 [L], the height from the bottom of the recovery container 81 to the liquid level of the start liquid is 35 [mm]. ]Met. With such a configuration, three antifoaming agent blocks 90 are arranged at intervals of 30 [mm] in the height direction upward from the liquid surface of the start liquid. As the liquid amount of the antifoaming liquid BL mixed with the liquid fixing liquid TL increases with time and the liquid level rises, the viscosity of the antifoaming liquid BL also increases, so the rotational speed of the recovery liquid stirrer 82 is also a little. Control to raise each step. In the foam recovery apparatus 70 of Example 1 as described above, the residual foam fixing solution Bu4 is recovered until the defoaming liquid BL whose amount is increased to 1.3 [L] by the liquid fixing liquid TL from which the foam is removed. I was able to.

[Example 2]
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 35 [μm].
In the foam-like fixing solution supply unit 130, a DES-based fixing solution is prepared based on the above-mentioned “adjustment of the foaming agent solution and the softening agent solution (2)”, and the gas / liquid mixing unit 35 and the bubble refining unit 38 A foamy fixer Bu was produced. The foam-like fixing solution Bu is formed on the transfer paper P on which the unfixed toner T is formed as a foam-like fixing solution film Bu3 having a thickness of about 80 [μm] on the application roller 41 of the foam-like fixing solution application unit 140. Applied.

  In Example 2, a silicone-based antifoaming agent (powder type KM-88P: manufactured by Shin-Etsu Chemical Co., Ltd.) was used as an antifoaming agent. A defoaming liquid BL made of an aqueous solution containing 1.0 [%] of powder type KM-88P as a start liquid is previously stored in a recovery container 81 having a capacity of 1.5 [L], and the recovery liquid The defoaming liquid BL is stirred with the stirrer 82. Further, an antifoam block 90 formed by encapsulating a powder type KM-88P as a defoamer with a thin layer of PVA is disposed on the inner wall surface in the collection container 81 using an antifoam holder 91. did. Similarly to Example 1, in Example 2, when 300 [mL] of the start liquid was put into the recovery container 81 having a capacity of 1.5 [L], the bottom of the recovery container 81 to the liquid surface of the start liquid was used. The height was 35 [mm]. With such a configuration, three antifoaming agent blocks 90 are arranged at intervals of 30 [mm] in the height direction upward from the liquid surface of the start liquid. As the liquid amount of the antifoaming liquid BL mixed with the liquid fixing liquid TL increases with time and the liquid level rises, the viscosity of the antifoaming liquid BL also increases, so the rotational speed of the recovery liquid stirrer 82 is also a little. Control to raise each step. In such a foam recovery apparatus 70 of Example 2, the remaining foam-like fixing liquid Bu4 is recovered until the defoaming liquid BL whose liquid amount is increased to 1.3 [L] by the liquid fixing liquid TL from which the foam is removed. I was able to.

Example 3
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 30 [μm].
In the foam-like fixing solution supply unit 130, a DES-based fixing solution is prepared based on the above-mentioned “adjustment of the foaming agent solution and the softening agent solution (2)”, and the gas / liquid mixing unit 35 and the bubble refining unit 38 A foamy fixer Bu was produced. The foam-like fixing solution Bu is formed on the application roller 41 of the foam-like fixing solution application unit 140 as a foam-like fixing solution film Bu3 having a thickness of about 95 [μm] on the transfer paper P on which the unfixed toner T is formed. Applied.

  In Example 3, polyacrylamide was used as an antifoaming agent. A defoaming liquid BL made of an aqueous solution containing 1.0 [%] of a powdered polyacrylic acid amide as a starting liquid is previously stored in a collecting container 81 having a capacity of 1.5 [L] and collected. The defoaming liquid BL is stirred with the liquid stirring element 82. Further, an antifoaming agent block 90 formed by encapsulating a powdered polyacrylic acid amide as an antifoaming agent with a thin layer of PVA is used on the inner wall surface in the recovery container 81 by using an antifoaming agent holder 91. Arranged. Similarly to Example 1, in Example 3, when 300 [mL] of the start liquid was put into the recovery container 81 having a capacity of 1.5 [L], the bottom of the recovery container 81 to the liquid surface of the start liquid was used. The height was 35 [mm]. With such a configuration, three antifoaming agent blocks 90 are arranged at intervals of 30 [mm] in the height direction upward from the liquid surface of the start liquid. As the liquid amount of the antifoaming liquid BL mixed with the liquid fixing liquid TL increases with time and the liquid level rises, the viscosity of the antifoaming liquid BL also increases, so the rotational speed of the recovery liquid stirrer 82 is also a little. Control to raise each step. In such a foam recovery device 70 of Example 3, the remaining foam-like fixing liquid Bu4 is recovered until the defoaming liquid BL whose liquid volume is increased to 1.3 [L] by the liquid fixing liquid TL from which the foam is removed. I was able to.

Example 4
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 30 [μm].
In the foam-like fixing solution supply unit 130, a PC-based fixing solution is prepared based on the above “adjustment of the foaming agent solution and the softening agent solution (1)”, and the gas / liquid mixing unit 35 and the bubble refining unit 38 A foamy fixer Bu was produced. The foam-like fixing solution Bu is formed on the transfer sheet P on which the unfixed toner T is formed as a foam-like fixing solution film Bu3 having a thickness of about 90 [μm] on the application roller 41 of the foam-like fixing solution application unit 140. Applied.

  In Example 4, polyacrylamide was used as an antifoaming agent. A defoaming liquid BL made of an aqueous solution containing 1.0 [%] of a powdered polyacrylic acid amide as a starting liquid is previously stored in a collecting container 81 having a capacity of 1.5 [L] and collected. The defoaming liquid BL is stirred with the liquid stirring element 82. Further, an antifoaming agent block 90 formed by encapsulating a powdered polyacrylic acid amide as an antifoaming agent with a thin layer of PVA is used on the inner wall surface in the recovery container 81 by using an antifoaming agent holder 91. Arranged. Similarly to Example 1, in Example 4, when 300 [mL] of the start liquid was put into the recovery container 81 having a capacity of 1.5 [L], the bottom of the recovery container 81 to the liquid level of the start liquid was used. The height was 35 [mm]. With such a configuration, three antifoaming agent blocks 90 are arranged at intervals of 30 [mm] in the height direction upward from the liquid surface of the start liquid. As the liquid amount of the antifoaming liquid BL mixed with the liquid fixing liquid TL increases with time and the liquid level rises, the viscosity of the antifoaming liquid BL also increases, so the rotational speed of the recovery liquid stirrer 82 is also a little. Control to raise each step. In the foam recovery apparatus 70 of Example 4 as described above, the residual foam-like fixer Bu4 is recovered until the antifoaming liquid BL whose amount is increased to 1.3 [L] by the liquid fixer TL from which the foam is removed. I was able to.

  In the configurations of Examples 1 to 4, the same defoaming effect was maintained when the same experiment was performed in the range of the concentration of the antifoaming agent in the range of 0.8 [%] to 3.0 [%].

[Comparative Example 1]
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 30 [μm].
In the foam-like fixing solution supply unit 130, a PC-based fixing solution is prepared based on the above “adjustment of the foaming agent solution and the softening agent solution (1)”, and the gas / liquid mixing unit 35 and the bubble refining unit 38 A foamy fixer Bu was produced. The foam-like fixing solution Bu is formed on the application roller 41 of the foam-like fixing solution application unit 140 as a foam-like fixing solution film Bu3 having a thickness of about 95 [μm] on the transfer paper P on which the unfixed toner T is formed. Applied.

  In Comparative Example 1, an antifoaming agent is not used, and a defoaming liquid BL consisting only of pure water as a start liquid is previously stored in a collection container 81 having a capacity of 1.5 [L], and the collected liquid is stirred. The defoaming liquid BL is stirred by the child 82. Similarly to Example 1, in Comparative Example 1, when 300 [mL] of the start liquid was placed in the recovery container 81 having a capacity of 1.5 [L], the bottom of the recovery container 81 to the liquid surface of the start liquid was used. The height was 35 [mm]. In addition, it controlled so that the rotation speed of the collection liquid stirring element 82 may be raised little by little like Examples 1-4, and the defoaming performance was confirmed.

[Comparative Example 2]
An unfixed toner color image was formed on PPC paper (Ricoh T-6200, A4 paper) as transfer paper P using an electrophotographic printer (IpsioColor CX8800 manufactured by Ricoh). The thickness of the toner layer was 20 to 30 [μm].
In the foam-like fixing solution supply unit 130, a DES fixing solution is prepared based on the above-mentioned “adjustment of the foaming agent solution and the softening agent solution (2)”, and bubbles are generated by the gas / liquid mixing unit 35 and the bubble refining unit 38. A fixing solution Bu was produced. The foam-like fixing solution Bu is formed on the application roller 41 of the foam-like fixing solution application unit 140 as a foam-like fixing solution film Bu3 having a thickness of about 100 [μm] on the transfer paper P on which the unfixed toner T is formed. Applied.

  In Comparative Example 2, an antifoaming agent BL was used in advance, and the defoaming solution BL consisting only of pure water as a starting solution was accommodated in a collection container 81 having a capacity of 1.5 [L] without using an antifoaming agent, The defoaming liquid BL is stirred by the child 82. Similarly to Example 1, in Comparative Example 1, when 300 [mL] of the start liquid was placed in the recovery container 81 having a capacity of 1.5 [L], the bottom of the recovery container 81 to the liquid surface of the start liquid was used. The height was 35 [mm]. In addition, it controlled so that the rotation speed of the collection liquid stirring element 82 may be raised little by little like Examples 1-4, and the defoaming performance was confirmed.

  In the fixing device 30 of Comparative Example 1 and Comparative Example 2, when the foam-like fixing solution Bu was continuously supplied to the recovery container 81 at 100 [mg / sec] for 1 [hour], bubbles overflowed from the recovery container 81. . This means that when 360 [g] of the foam-like fixing solution Bu is collected, the foam overflows. Since the specific gravity of the liquid fixing solution TL is about 1 [g / mL], the liquid fixing solution TL overflows when the foamy fixing solution Bu that is about 360 [mL] is recovered. Bubbles overflowed in a state in which a liquid of 660 [mL] obtained by adding 300 [mL] of the start liquid to this was in the collection container 81. This was confirmed that the recovery ability was insufficient as compared with Examples 1 to 4 in which the liquid of 1.3 [L] was recovered, and the antifoaming property and the antifoaming durability were insufficient. .

In the first to fourth embodiments, the antifoaming liquid BL containing antifoaming agent is added to the recovery container 81 of the antifoaming apparatus 80, and the antifoaming agent added to the inner wall surface of the recovery container 81 is accommodated. Antifoam block 90 is arranged in stages. In such a configuration, at the beginning of the recovery of the residual foam fixing liquid Bu4, the residual foam fixing liquid Bu4 is defoamed by the defoaming action of the antifoaming agent contained in the start liquid to become a liquid fixing liquid TL. Further, when the liquid amount of the antifoaming liquid BL mixed with the liquid fixing liquid TL is increased over time, the antifoaming composed of a thin layer of PVA of the antifoaming agent block 90 that is in contact with the antifoaming liquid BL due to the rise of the liquid level. The agent storage member is dissolved by moisture in the antifoaming liquid BL. Thereby, the antifoaming agent contained in the antifoaming agent containing member is dissolved in the antifoaming liquid BL, and stirred and separated, so that the antifoaming effect of the antifoaming liquid BL whose antifoaming effect is reduced over time is restored. I can do it. For this reason, the defoaming performance in the defoaming liquid BL can be maintained, and the collected foam is accommodated in the collection container 81 without overflowing.
On the other hand, in Comparative Example 1 and Comparative Example 2, the antifoaming agent is not contained in the start liquid, and no antifoaming agent is added, so that the recovery container 81 is immediately filled with the foamed fixing liquid Bu. As a result, the recovery container 81 becomes full in a short time.

  As described above, the defoaming device 80 included in the fixing device 30 of the present embodiment is in the solution of the fixing solution F that dissolves or swells at least a part of the toner as the resin component and fixes the toner on the transfer paper P as the recording medium. This is a defoaming device that breaks the bubble-shaped fixing solution Bu in which bubbles are dispersed to form a liquid fixing solution TL. Since the defoaming device 80 breaks the foam fixing solution Bu with the defoaming agent, the foam fixing solution Bu can be defoamed with less energy than the heating to form the liquid fixing solution TL.

  The antifoaming device 80 includes a recovery container 81 that is a fixing liquid recovery container that recovers and stores the foamy fixing liquid Bu, and stores the antifoaming liquid BL containing the antifoaming agent in the recovery container 81. By contacting the recovered foam fixing solution Bu with the defoaming solution BL, the foam fixing solution Bu is broken to be mixed with the antifoaming solution BL as a liquid fixing solution TL, and the liquid fixing solution TL in the recovery container 81 is mixed. The antifoaming agent is added stepwise to the defoaming liquid BL in accordance with the liquid volume of the antifoaming liquid BL mixed. The antifoaming liquid BL containing the antifoaming agent increases the accumulated amount of the recovered liquid fixing liquid TL, and the antifoaming agent contained in the antifoaming liquid BL over time with only the antifoaming agent contained in the starter liquid. As a result, the defoaming effect decreases. However, in order to prevent the concentration of the antifoaming agent from decreasing, even if a high concentration antifoaming solution BL containing a large amount of the antifoaming agent is used as the starting solution, the antifoaming agent is not added to the offset toner or the aggregate. Adsorption reduces the defoaming effect. On the other hand, by adding the antifoaming agent stepwise to the antifoaming solution BL, the antifoaming effect has been reduced by the defoaming agent concentration reduction or adsorption of the antifoaming agent to the aggregates before the addition. The defoaming effect of the liquid BL can be restored.

  In the defoaming device 80, the defoaming agent is attached to a part of the collection container 81 as the defoaming agent block 90. Thereby, the structure which adds an antifoamer to the antifoam liquid BL in the collection container 81 with a simple structure is realizable.

  Further, the antifoaming device 80 includes an antifoaming agent block 90 formed by accommodating the antifoaming agent in the antifoaming agent containing member on the inner wall surface of the collection container 81, and the antifoaming agent containing member is the antifoaming liquid BL. It is made of polyvinyl alcohol (PVA), which is a material that dissolves when the moisture contained in it comes into contact. And the antifoamer accommodation member melt | dissolves with the antifoam liquid BL in the collection container 81, and the accommodated antifoamer is added to the antifoam liquid BL. With such a configuration, an antifoaming agent can be added stepwise to the antifoaming liquid BL according to the amount of the antifoaming liquid BL in the collection container 81.

  Further, in the antifoaming device 80, the antifoaming agent blocks 90 are arranged at five locations on the inner wall surface of the collection container 81 at different heights by the antifoaming agent holder 91. By arranging the antifoaming agent block 90 at a plurality of places having different heights as described above, the antifoaming liquid BL arrives when the liquid level of the antifoaming liquid BL rises due to an increase in the antifoaming liquid BL over time. The antifoaming agent in the antifoaming block 90 at a height is sequentially added to the antifoaming solution BL. Thereby, the structure which adds an antifoamer to the antifoam liquid BL in steps according to the liquid quantity of the antifoam liquid BL in the collection container 81 is realizable.

  Moreover, in the defoaming apparatus 80, as shown in FIG.13 and FIG.14, the defoaming apparatus 80 is five from the lower direction of the collection | recovery container 81 to the 1st antifoamer block 90a-the 5th antifoamer block 90e. An antifoaming agent block 90 is arranged, and as these five antifoaming agent blocks 90, the amount of antifoaming agent accommodated in the antifoaming agent accommodating member may be increased as the antifoaming agent block 90 arranged above. . Thereby, according to the liquid quantity of the antifoam liquid BL in the collection container 81, it increases the addition amount of the antifoamer added in steps to the antifoam liquid BL as the liquid quantity of the antifoam liquid BL increases. Can be made. By increasing the amount of the antifoaming agent as the amount of the antifoaming solution BL increases, the concentration of the antifoaming agent can be maintained even if the amount of the antifoaming solution BL is increased.

  Further, the defoaming device 80 includes a recovery liquid stirrer 82 that is a stirring means for stirring the antifoam liquid BL in the recovery container 81 and a magnetic stirrer (not shown). Thereby, the density | concentration of the defoaming liquid BL to which an antifoamer is added in steps can be made uniform. Furthermore, by stirring the antifoaming liquid BL, the chance that the residual foam-like fixing liquid Bu4 recovered above and the antifoaming liquid BL come into contact can be increased, and the defoaming can be performed more efficiently.

  Further, the fixing device 30 of the present embodiment is a foam-like liquid in which bubbles are dispersed in a liquid fixing solution TL containing a softening agent that softens toner, which is resin fine particles, by dissolving or swelling at least part of the resin. A foam-like fixing liquid Bu is formed on the surface of the transfer paper P, which is a fixing liquid application target carrying the unfixed toner T made of resin fine particles, and a foam-like fixing liquid supply unit 130 which is a fixing liquid foaming means to be the fixing liquid Bu. It has a foam fixing solution application unit 140 that is a foam fixing solution applying means for applying, and the toner softened by applying the foam fixing solution Bu is fixed to the transfer paper P. In such a fixing device 30, by using the defoaming device 80 as a foam fixing solution defoaming means that collects the foam fixing solution Bu and breaks it to obtain a liquid fixing solution TL, the foam fixing solution Bu is used. Thus, the liquid fixing solution TL can be efficiently and reliably obtained, so that the space for storing the recovered fixing solution can be reduced, and the fixing device 30 as a whole can be reduced in size. Furthermore, since the foamy fixing solution Bu can be defoamed into the liquid fixing solution TL with less energy than heating, energy saving of the fixing device 30 can be achieved.

Further, the fixing device 30 becomes the foamy fixing solution Bu by the foamy fixing solution supply unit 130 and is not applied to the transfer paper P, but remains on the application roller 41 which is a surface moving body, and the residual foamed fixing solution Bu4. The foam recovery device 70 is a foam fixer cleaning means for recovering and cleaning the foam, and the residual foam fixer Bu4 recovered by the foam recovery device 70 is used as the liquid fixer TL by the defoamer 80. Since the foam-like fixing liquid Bu is large (bulk density is small), for example, even if several percent of the foam-like fixing liquid Bu that has entered the application nip C remains on the application roller 41, it remains on the surface of the application roller 41. If the foamed fixing solution Bu is left as it is, there is a risk that normal fixing operation may be hindered or surroundings may be contaminated. On the other hand, in the fixing device 30, the residual foam fixing solution Bu4 on the surface of the application roller 41 is recovered by the foam recovery device 70 and liquefied and stored by the defoaming device 80. It is possible to prevent the occurrence of problems caused by leaving it as it is.
Further, the defoaming device 80 provided with the features of the present invention is limited to a configuration that defoams the foam-like fixing liquid Bu collected from the surface of the application roller 41 as in the fixing device 30 of the above-described embodiment. It is not a thing. For example, as described in Patent Document 5, the configuration is such that a foamy fixing solution is applied to the intermediate transfer belt, and the foaming fixing solution remaining on the intermediate transfer belt and removed by the removing means is also applied to the configuration. It's ok.

  In addition, the printer 100 according to this embodiment includes an image forming unit (each color) that is a toner image forming unit that forms a toner image on the transfer paper P that is a recording medium using toner including resin fine particles containing a resin and a colorant. Process unit 3, intermediate transfer belt 25, etc.). Further, the printer 100 includes a fixing unit that applies a fixing liquid to the surface of the transfer paper P carrying the toner image and fixes the toner image on the transfer paper P. The printer 100 can reduce the size of the entire printer 100 by using the fixing device 30 including the defoaming device 80 as a fixing unit, and can save energy of the fixing device 30, thereby reducing the entire printer 100. Energy saving.

4 Photoconductor 25 Intermediate transfer belt 29 Paper transport belt 30 Fixing device 41 Coating roller 42 Film thickness adjusting blade 43 Pressure roller 70 Foam recovery device 71 Foam recovery blade 73 Foam guide member 77 Foam recovery belt 80 Defoaming device 81 Recovery container 82 Recovery liquid stirrer 83 Foam scraping blade 90 Antifoam block 91 Antifoam holder 100 Printer 130 Foam fixing liquid supply section 140 Foam fixing liquid application section 340 Liquid fixing liquid transport pipe 400 Liquid mixing section BL Antifoam liquid Bu Foam Fixer Bu4 Residual Foam Fixer C Coating Nip TL Liquid Fixer

Japanese Patent No. 3290513 Japanese Patent No. 4185742 JP 59-119364 A JP 2007-219105 A JP 2002-91260 A

"Foam Engineering" first edition (written by Ishii Ikuo, Techno System, Inc., published on March 25, 2005, P.489)

Claims (10)

In the defoaming apparatus, a foamed fixing solution in which bubbles are dispersed in a solution of a fixing solution that dissolves or swells at least a part of the resin component and is fixed on a recording medium is used as a liquid fixing solution.
An antifoaming device, wherein the foamy fixing solution is broken by an antifoaming agent. The defoaming device of claim 1,
A fixing solution collecting container for collecting and storing the foamy fixing solution;
An antifoaming solution containing the antifoaming agent is accommodated in the fixing solution recovery container, and the recovered foamy fixing solution is brought into contact with the antifoaming solution to break up the foamy fixing solution to be liquid. Mixed with the antifoaming solution as a fixer,
An antifoaming apparatus, wherein the antifoaming agent is added stepwise to the antifoaming liquid according to the amount of the antifoaming liquid mixed with the liquid fixing liquid in the fixing liquid recovery container. The defoaming device of claim 2,
The antifoaming apparatus, wherein the antifoaming agent is attached to a part of the fixer recovery container. The defoaming device of claim 3,
An antifoaming agent containing member for containing the antifoaming agent is attached to the inner wall surface of the fixing solution recovery container, and the antifoaming agent containing member is made of a material that dissolves when the antifoaming solution comes in contact with it,
An antifoaming apparatus, wherein the antifoaming agent containing member is added to the antifoaming liquid when the antifoaming agent containing member is dissolved by the antifoaming liquid in the fixing liquid recovery container. In the defoaming device according to any one of claims 2 to 4,
The antifoaming apparatus is characterized in that the antifoaming agent is attached to a plurality of locations having different heights on the inner wall surface of the fixer recovery container. In the defoaming device according to any one of claims 2 to 5,
In accordance with the amount of the antifoaming liquid in the fixing solution recovery container, the amount of the antifoaming agent added stepwise to the antifoaming liquid is increased as the amount of the antifoaming liquid increases. An antifoaming device characterized by causing In the defoaming device according to any one of claims 2 to 6,
A defoaming apparatus comprising stirring means for stirring the defoaming liquid in the fixing liquid recovery container. A fixing liquid foaming means for forming a liquid fixing liquid containing a softening agent that softens resin fine particles by dissolving or swelling at least a part of the resin into a foamy fixing liquid in which bubbles are dispersed in the liquid;
A foam-like fixing solution applying means for applying the foam-like fixing solution to the surface of the fixing solution application target carrying the resin particle layer composed of the resin particles;
In a fixing device for fixing the resin fine particles softened by applying the foamy fixing solution to a recording medium,
The foamy fixing solution is collected, and is equipped with a foamy fixing solution defoaming means that breaks the foam into the liquid fixing solution.
A fixing device using the defoaming device according to any one of claims 1 to 7 as the foam-like fixing solution defoaming means. The fixing device according to claim 8.
Foam fixer cleaning means for recovering and cleaning the foam fixer in the state that it becomes the foam fixer by the fixer foaming means and is not applied to the fixer application target but attached to the surface moving body. With
A fixing device characterized in that the foam-like fixing solution recovered by the foam-like fixing solution cleaning means is converted into the liquid fixing solution by the foam-like fixing solution defoaming means. A toner image forming means for forming a toner image on a recording medium using a toner containing resin fine particles containing a resin and a colorant;
Fixing means for applying a fixing liquid to the surface of the toner image carrier that carries the toner image to be transferred to the recording medium or the surface of the recording medium that carries the toner image and fixing the toner image on the recording medium; An image forming apparatus comprising:
An image forming apparatus using the fixing device according to claim 8 or 9 as the fixing unit.

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