JP2009110029A - Fixing solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing solution for resin fine particles, which can quickly fix resin fine particles containing a resin such as toner to a recording medium such as paper after applying the fixing solution to the recording medium having the resin fine particles adhered thereon without disarranging the fine particles on the recording medium, and further can be applied in a minute amount such that a sense of residual oil is never caused on the recording medium. <P>SOLUTION: In a fixing device for applying a foam-like (bubble-like) fixing solution onto resin fine particles formed on a recording medium by electrostatic recording process to fix the resin fine particles to the recording medium, the foam-like fixing solution 20 contains a softener 21 which dissolves or swells at least a part of the resin fine particles to soften the resin fine particles, foaming agent, and a foam booster. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixing solution, and more particularly to a foam-like fixing solution for fixing resin-containing fine particles containing resin fine particles to a recording medium.

  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. In particular, electrophotographic image forming apparatuses are widely used in offices because they can form high-definition images on plain paper at high speed. In such an electrophotographic image forming apparatus, a heat fixing method is widely used in which toner on a recording medium is heated and melted, and the molten toner is pressurized to fix the toner on the recording medium. Yes. This thermal fixing method is preferably used because it can provide a high fixing speed and high fixed image quality.

  However, about half or more of the power consumption in such an electrophotographic image forming apparatus is consumed in heating the toner in the heat fixing method. On the other hand, a low power consumption (energy saving) fixing device is desired from the viewpoint of countermeasures for environmental problems in recent years. That is, there is a demand for a fixing method in which the temperature for heating the toner for fixing the toner is extremely lowered than before, or the toner does not need to be heated. In particular, the non-heat fixing method in which the toner is fixed to the recording medium without heating the toner at all is ideal in terms of low power consumption.

  As such a non-heat fixing method, for example, an oil-in-water type fixing agent in which a toner can be dissolved or swelled and an organic compound insoluble or hardly soluble in water is dispersed and mixed in water is used. Patent Document 1 proposes a toner wet fixing method in which a toner is dissolved or swollen by spraying or dripping from the surface of the fixing object disposed at the position, and then the fixing object is dried.

  However, in the wet fixing method disclosed in Patent Document 1, an oil-in-water type fixing agent in which an organic compound insoluble or hardly soluble in water is dispersed and mixed in water is used. When applied to the recording medium, the recording medium such as transfer paper (non-fixed material) absorbs moisture of the fixing agent, and the recording medium is wrinkled and curled. This significantly impairs the stable and high-speed conveyance of the recording medium required for the image forming apparatus. Therefore, if water is removed from the fixing agent applied to the recording medium by evaporating a large amount of water contained in the fixing agent using a drying device, the power consumption of the image forming apparatus using the thermal fixing method is reduced. 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, an aliphatic dibasic acid ester or the like containing a material that dissolves or swells a resin component constituting a toner as a diluent (solvent) is diluted with nonvolatile dimethyl silicone. Fixing solutions (dissolved) have been proposed. In Patent Document 3, toner is used as a fixing solution that can be used in a fixing method in which an unfixed image formed by an electrostatic method can be clearly and easily fixed on an image receiving sheet without disturbing the image. A solution for fixing an unfixed toner image in a compatible state, in which 8 to 120 parts by volume of a silicone oil is mixed with 100 volumes of a solvent that is dissolved and compatible with the silicone oil, has been proposed. 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-processed unfixed toner, The toner can be fixed on the recording medium.

  However, in any of the above-mentioned patent documents, the liquid is applied to the unfixed toner layer. However, as shown in FIG. 13A, the application roller 1 is used as the contact application means on the recording medium 2. In the configuration in which the fixing liquid is applied to the unfixed toner layer 3, when the thickness of the fixing liquid layer 4 on the application roller 1 is thinner than the unfixed toner layer 3, the application roller 1 is separated from the recording medium at the position where the application roller 1 is peeled off from the recording medium. The unfixed toner particles are pulled by the surface tension generated by the liquid film of the fixing liquid on the surface 1 and offset on the surface of the coating roller 1, and the image on the recording medium 2 is greatly disturbed. Conversely, as shown in FIG. 13B, when the thickness of the fixing liquid layer 4 on the application roller 1 is sufficiently thicker than the unfixed toner layer 3, the application roller 1 is separated from the recording medium 2. Since the amount of liquid is large, the surface tension due to the liquid film on the surface of the coating roller 1 does not directly act on the toner particles, and the toner is not offset on the roller side, but a large amount of fixing liquid is applied to the paper surface and the drying time is long. As a result, a problem occurs in the fixing response. In addition, a noticeable residual liquid feeling (a wet feeling when the paper is touched by hand) occurs on the paper. Therefore, in such a configuration in which the roller coating is performed with the fixing liquid, a small amount of the fixing liquid is applied to the toner layer on the paper and the toner offset is prevented from being applied to the fixing roller in order to improve the fixing response and reduce the residual liquid feeling. It is extremely difficult. Even when a die coating unit, a blade coating unit, or a wire bar coating unit is used as the contact coating unit, if the amount of the fixing solution is small, the toner is offset by the surface tension on the contact coating unit.

  As described above, in the conventional fixing solution formulation, the contact coating means can achieve both the application of a small amount of the fixing solution to the toner layer on the paper and the uniform application of the toner image without any disturbance in order to improve the fixing responsiveness. Is extremely difficult.

  The present invention is for solving these problems, and the fixing liquid is applied to the recording medium to which the resin fine particles are adhered without disturbing the fine particles containing resin such as toner on the recording medium such as paper. Thereafter, an object of the present invention is to provide a fixing solution of resin fine particles in which resin fine particles can be quickly fixed on a recording medium, and can be applied in a minute amount so as not to cause residual oil on the recording medium.

  In order to solve the above problems, the fixing solution of the present invention is a fixing solution in which a foam-like fixing solution is applied to resin fine particles formed on a recording medium by an electrostatic recording process to fix the resin fine particles on the recording medium. The apparatus is characterized in that the foam-like fixing solution contains a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin fine particles, and a foaming agent and a foaming agent. Therefore, a bubble layer having finer bubbles in the foam-like fixing solution and excellent particle size uniformity can be formed, and fixing reliability is improved.

  Further, since the fixing solution contains a diluting solvent for diluting the softening agent, excessive softening of the resin fine particles can be prevented, and the tackiness (adhesion feeling) of the resin fine particle layer after fixing can be suppressed.

  Furthermore, since the softener is dissolved in the diluting solvent, the storage stability of the liquid component is excellent.

  In addition, since the softener is dispersed in the diluent solvent, the softener type and diluent solvent type selectivity is higher than the dissolving configuration, so it is possible to optimize the softener and select low-cost materials. , Effective in improving performance and reducing costs.

  Furthermore, by dissolving or dispersing the liquefied gas or compressed gas in the fixer, it is possible to use a high-pressure sealed container, and it is possible to produce a fixer that is the most dense and contains fine bubbles in the form of a foam. .

The softener preferably contains an aliphatic ester. The aliphatic ester preferably contains a saturated aliphatic ester. Further, the saturated aliphatic ester includes a compound represented by the general formula R1COOR2, wherein R1 is an alkyl group having 11 to 14 carbon atoms, and R2 is an alkyl group having 1 to 6 carbon atoms. . The aliphatic ester preferably contains an aliphatic dicarboxylic acid ester. Furthermore, the aliphatic dicarboxylic acid ester includes a compound represented by the general formula R3 (COOR4) ₂ , wherein R3 is an alkylene group having 3 to 8 carbon atoms, and R4 has 2 to 5 carbon atoms. It is an alkyl group. Moreover, it is preferable that aliphatic ester contains aliphatic dicarboxylic acid dialkoxyalkyl. Furthermore, the aliphatic dicarboxylic acid dialkoxyalkyl includes a compound represented by the general formula R5 (COOR6-O-R7) ₂ , wherein R5 is an alkylene group having 2 to 8 carbon atoms, and R6 is carbon. It is an alkylene group having 2 to 4 carbon atoms, and R7 is an alkyl group having 1 to 4 carbon atoms.

  Further, when the softening agent dilution solvent contains water and monohydric or polyhydric alcohols, the safest fixing solution can be prepared and the environment can be taken into consideration.

  In addition, since the diluting solvent for the softening agent is a non-aqueous non-volatile diluting solvent by containing an olefin compound, the occurrence of curling and paper wrinkles can be suppressed with respect to a medium such as paper.

  Furthermore, since the diluting solvent of the softening agent contains dimethyl silicone, it is a non-aqueous non-volatile diluting solvent, so that curling and wrinkling can be suppressed with respect to a medium such as paper.

  The fixing solution of the present invention is a foam-like fixing solution that is produced by the foam-like fixing solution producing means and the film thickness controlling means and whose film thickness is controlled, and formed on the recording medium by an electrostatic recording process. A softener that softens the resin fine particles by dissolving or swelling at least part of the resin fine particles, a foaming agent, and a foaming agent are contained. Therefore, it is possible to provide a fixing liquid capable of fixing in a small amount and having excellent fixing response without disturbing the resin fine particles on the medium by preventing the offset to the coating member in the contact coating.

FIG. 4 is an enlarged view of a portion where a roller application surface and an unfixed resin fine particle are in contact with each other when the pressure on the contact surface between the application roller and the recording medium is high in the roller application unit in the fixing device. FIG. 5 is an enlarged view of a portion where a roller coating surface and an unfixed resin fine particle are in contact with each other when the pressure on the contact surface between the coating roller and the recording medium is low in the roller coating unit in the fixing device. It is the schematic which shows the layer structural example of the foam-form fixing solution at the time of application | coating. FIG. 6 is a diagram illustrating a change in the fixing solution after the fixing solution is applied. FIG. 5 is a schematic view showing a state in which a foam-like fixing liquid is applied to an application roller by a fixing liquid application unit. It is the schematic which shows an example of a foam-form fixing liquid production | generation means and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of a foam-form fixing liquid production | generation means and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of a foam-form fixing liquid production | generation means and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of a foam-form fixing liquid production | generation means and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of a foam-form fixing liquid production | generation means and a foam-form fixing liquid layer film thickness control means. 1 is a schematic diagram illustrating a configuration of an image forming apparatus. It is the schematic which shows the mode of the bubble by the optical microscope observation in a foam-like fixing liquid layer. It is the schematic which shows the mode of the fixing by the conventional fixing device.

11, 32, 42, 55, 65; coating roller, 12, 20, 33; fixing solution;
13, 22; bubbles, 14; fixer layer, 15, 31; resin fine particles,
21; liquid, 41; fixing solution supply roller, 43; stirring roller,
44; Fixing liquid sealed container, 45; Liquid conveying pipe,
46, 54; liquid supply port, 51, 62; sealed container, 52; actuator,
53; nozzle, 56; blade, 61; stirring blade, 63; pressure cylinder,
64; fixing solution replenishment pad, 71; coating belt,
81; cylindrical stencil member, 82; press roller,
83; Application member, 84; Groove roller.

  First, the principle of the present invention will be described. The present invention focuses on the fact that a foam-like liquid containing a large amount of bubbles has a very low bulk density. As described above, in order to perform application that does not cause offset to the roller by roller application as a contact application unit, the fixing liquid layer on the application roller needs to be thick. This means that a certain amount of fixer volume is required on the surface of the coating roller for uniform coating with no resin fine particle offset. On the other hand, the smaller the amount of the fixing solution on the resin fine particle layer on the medium after coating, the better the fixing responsiveness and the residual liquid feeling, which means that it is desirable that the weight of the fixing solution is small. In order to satisfy the condition that the volume of the fixing solution is large and the weight of the fixing solution on the medium after coating is small, it is sufficient that the density of the fixing solution is low. The coating weight can be reduced. That is, the object of the present invention can be achieved by using a fixing solution having a low bulk density (a value obtained by dividing the weight of the fixing solution by its volume).

  Focusing on this principle, the present applicant has disclosed a technique for applying a foam-like fixing solution to an intermediate transfer belt in the above-mentioned Patent Document 4, and has proposed a small amount of application using a foam-like fixing solution. However, the technique in Patent Document 4 is mainly intended to reduce the amount of the fixing solution, and is not the prevention of offset and image flow, which is the purpose of the present invention. Japanese Patent Application Laid-Open No. H10-228707 only has a configuration in which a foam-like fixing solution is applied by flying to an unfixed toner layer on an intermediate transfer member, and is directly applied to unfixed toner on a medium such as paper by a contact coating means such as roller coating. There is no mention of coating and fixing configuration or film thickness control. In contact coating such as roller coating, it is possible to supply a foam-like fixer containing fine bubbles to an unfixed toner image uniformly in a thin layer, and uneven coating is less likely to occur. In addition, the roller coating with a fixing solution containing bubbles in the fixing solution was studied, and simply by applying the foam-like fixing solution, prevention of offset of resin fine particles to the roller surface in the roller coating. It has been found that is not always effective. Therefore, it has been found that in the roller application means, the bubble layer structure in the foam-like fixing solution on the coating roller surface and the film thickness control of the fixing solution layer containing the bubble layer are important for preventing offset.

  1 and 2 are enlarged views of a portion where the roller coating surface and the unfixed resin fine particles are in contact with each other in the roller coating unit of the fixing device. FIG. 1 shows a case where the pressure applied on the contact surface between the application roller 11 and the recording medium is high, and FIG. 2 shows a case where the pressure is low. As shown in FIG. 1A, the foam-like fixing liquid 12 has a single-layer structure of bubbles 13 on the application surface of the application roller 11, and the bubble diameters in FIGS. 1 and 2 are the same. The layer thickness of the foam-like fixing solution 12 is thinner than that in FIG. However, as shown in FIG. 1A, since the bubbles 13 are a single layer, the bubbles themselves are likely to adhere to the application surface of the application roller 11 due to surface tension, and the fixing liquid 12 is not uniform on the layer of the resin fine particles 15. The resin fine particles 15 are adsorbed by the bubbles 13 and offset to the application surface of the application roller 11. On the other hand, as shown in FIG. 1B, when the foam-like fixing liquid 12 has a multi-layered bubble layer structure on the application surface of the application roller 11, bubbles are formed on the surface of the unfixed toner 15 having irregularities. The foam-like fixing liquid 12 can be easily separated between the layers of the bubbles 13 and can be uniformly applied to the toner layer as shown in FIG. 1B, so that toner offset can be hardly caused. .

  Therefore, when the pressure on the contact surface between the coating roller 11 and the recording medium is high, the average size of bubbles generated in advance is measured in order to prevent the unfixed toner 15 from being offset to the coating roller 11. If the film thickness of the foam-like fixing liquid layer on the coating roller 11 is controlled to be the thickness of the plurality of bubble layers so that the bubble layer becomes a plurality of layers, A foam-like fixing liquid layer composed of a plurality of bubble layers is always formed, and toner offset can be prevented.

  When the pressure on the contact surface between the application roller 11 and the recording medium is low, the foam-like fixing liquid 12 is a single layer of bubbles 13 on the application surface of the application roller 11 as shown in FIG. Due to the structure, bubbles easily adhere to the surface of the unfixed toner 15 having unevenness, the bubble layer is peeled off from the surface of the application roller 11, and the foam-like fixing liquid is applied to the unfixed toner 15. The On the other hand, as shown in FIG. 1B, when the foam-like fixing liquid 12 has a multi-layered bubble layer structure on the application surface of the application roller 11, the bubbles 13 are applied because the bonds between the bubbles 13 are strong. The unfixed toner 15 tends to remain on the roller 11 side, and conversely, the unfixed toner 15 adheres to the bubbles 13, and as a result, the unfixed toner 15 is offset on the surface of the application roller 11.

  Therefore, when the pressure on the contact surface between the coating roller 11 and the recording medium is low, the average size of the bubbles is measured in advance, and the foam-like fixing liquid having a single-layered bubble layer structure on the coating roller surface. If the thickness of the liquid layer is controlled so that a liquid film having a single-layer bubble layer structure is formed on the application roller, toner offset can be prevented under high pressure conditions. Further, in order to prevent the unfixed toner 15 from being offset to the coating roller 11, if the bubble layer on the coating roller 11 is too thick, the bubble layer flows at the contact portion between the coating roller and the recording medium, and the toner particles However, the problem of the flow of the image occurs, so that the problem can be solved by controlling the film thickness of the foam-like fixing liquid layer in such a range that the fluidity does not occur.

  As described above, by controlling the film thickness of the fixing liquid layer in accordance with the size and pressure of bubbles contained in the foam-like fixing liquid, the toner offset to the contact application means such as the application roller can be reduced. It is possible to prevent image flow and to fix by extremely minute application. The present invention is based on this principle.

  That is, the present invention uses a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin fine particles, and applying the fixer to the resin fine particles on the medium by contact coating means, When the fixing solution is applied to the surface of the resin fine particles on the medium, the fixing solution is in a foam-like form containing bubbles by applying the fixing solution to the fine particles. In addition, by controlling the film thickness of the foam-like fixer layer according to the applied pressure, toner offset to the contact application means such as the application roller and image flow can be prevented, and fixing by extremely minute application is possible. It can be. In addition, toner fine particles used in electrophotographic technology are highly effective for the present invention as resin fine particles, and offset and image flow are prevented by controlling the film thickness of the foam-like fixing liquid layer according to the layer thickness of the resin fine particles. it can.

  FIG. 3 is a schematic diagram showing a layer configuration example of a foam-like fixing solution at the time of application. The liquid 21 shown in the figure contains a softener and has a foam-like configuration in which bubbles 22 are contained in the liquid. Thus, the bulk density of the fixing solution 20 can be made extremely low by containing a large amount of the bubbles 22. With this configuration, as shown in FIG. 4, even when the fixing solution is applied, even if it is applied in a large volume, the bulk density is low and the application weight is small. For example, the substantial coating amount can be extremely reduced. In addition, the foam form in the present invention indicates a state where bubbles are dispersed in the liquid and the liquid is compressible.

  Next, the fixing solution applying unit will be described. The fixing solution applying means is a contact applying means. FIG. 5 is a schematic view showing a state in which a foam-like fixing solution is applied to the application roller by the fixing solution applying means. In the figure, resin fine particles 31 are toner particles. A layer of foam-like fixing liquid 33 is formed on the application roller 32, and the fixing liquid optimized according to the size and pressure of the foam-like fixing liquid 33 and the layer thickness of the unfixed toner. It is the thickness of the layer, and the resin fine particles 31 are not offset on the coating roller 32. Even if the foam-like fixing liquid 33 is thickly applied to the layer of the resin fine particles 31 and the recording medium, the bulk density of the foam-like fixing liquid 33 is extremely low, and thus is contained after a predetermined foam time has elapsed. When the bubbles break, a small amount can be applied to the liquid resin fine particle 31 layer containing the softening agent.

Incidentally, the bubble content in the foamed fixer varies according to the thickness of the bulk density and the coating layer, generally, as the bulk ^{density, 0.01g / cm 3 ~0.1g / cm} 3 approximately ranges desirable. Further, the foam-like fixing solution composed of a cellular layer means a foam-shaped fixing solution composed of a single layer or a plurality of cellular layers, and does not necessarily have a clear layer surface. Furthermore, the fixer is only required to be in the form of foam when applied to a layer of resin fine particles such as toner on a recording medium such as paper, and need not be in the form of a foam in the storage container. In the storage container, it is a liquid that does not contain bubbles, and it is desirable to provide a means for forming the foam in the liquid supply path until the liquid is supplied from the container or until it is applied to the resin fine particle layer. This is because the storage container is liquid, and the configuration in which the liquid is taken out from the container to form a foam has a great advantage that the container can be downsized.

Here, a method of forming a foam-like fixing solution containing bubbles after taking out the liquid fixing solution from the sealed container will be described.
As a first method, in a sealed container, after a liquid fixing solution containing a softening agent is taken out from the container, a large amount of bubbles are generated by a bubble generating means that generates a bubble by applying a shearing force to the liquid fixing solution. It is a method of containing. FIG. 6 shown as a specific example shows an example in which a stirring roller is used as means for applying a shearing force. In FIG. 5A, the fixing liquid hermetically sealed container that stores the fixing liquid in the nip portion between the fixing liquid supply roller 41 and the stirring roller 43 with the foam-shaped fixing liquid supply roller 41 once detached from the application roller 42. The liquid fixing liquid from the liquid supply port 46 is accumulated from 44 through the liquid conveying pipe 45, and the stirring roller 43 is rotationally stirred to form a foam-like fixing liquid, and then the fixing liquid supply roller 41 is applied to the coating roller 42. The foam-like fixing liquid is supplied to the coating roller 42 in contact therewith. Further, as shown in FIGS. 5A and 5B, the film of the fixing liquid layer optimized from the size and pressure of the foam-like fixing liquid bubbles on the roller surface of the coating roller 42 by the blade 47. The thickness is controlled.

  As a second method, as shown in FIG. 7, a liquefied gas or a compressed gas is put into a sealed container 51 together with a liquid fixing solution containing a softening agent, and an actuator 52 and a nozzle 53 attached to the sealed container 51 are used. A large amount of bubbles are contained in the liquid by the expansion of the liquefied gas or the compressed gas at the time of ejection, and a foam-like fixing liquid is prepared. From the liquid supply port 54 through the liquid transport pipe, the blade 56 is in contact with the coating roller 55. A foam-like fixing solution is supplied to the nip portion. The gap between the blade 56 and the coating roller 55 is adjusted, the film thickness of the foam-like fixing liquid layer on the coating roller 55 is controlled, and the fixing liquid optimized from the bubble size and pressure of the foam-like fixing liquid The film thickness of the layer is controlled.

  As a third method, as shown in FIG. 8, a stirring blade 61 is used as means for applying a shearing force, and a liquid fixing solution containing a softening agent is stirred in a sealed container 62 to form a foam-like fixing solution. Then, high-pressure air is sent from the pressure cylinder 63 to discharge the foam-like fixing liquid from the sealed container 62, and the foam-like fixing liquid is supplied to the application surface of the application roller 65 by the fixing liquid supply pad 64. Then, as shown in FIGS. 8A and 8B, the thickness of the foam-like fixing liquid on the application roller 65 is controlled by the wire bar 66, and the size and pressure of the foam-like fixing liquid bubbles are controlled. Thus, the film thickness of the fixer layer optimized is controlled. In addition, even if it is a liquid in an airtight container during long-term storage, it is configured to form a foam-like fixing liquid by stirring immediately before use.

  The fourth method is a method of applying to the unfixed toner on the recording medium using the application belt 71 instead of the application roller shown in FIG. When ejected from the actuator 52 and the nozzle 53 attached to the sealed container 51, a large amount of bubbles are contained in the liquid by the expansion of the liquefied gas or the compressed gas, and a foam-like fixing liquid is prepared, and the liquid is supplied through the liquid transport pipe. From the opening 54, a foam-like fixing liquid is supplied to the nip portion between the coating belt 71 and the blade 56 in contact therewith. Then, the gap between the blade 56 and the coating belt 71 is adjusted, the film thickness of the foam-like fixing solution layer on the coating belt 71 is controlled, and the fixing is optimized from the size and pressure of the foam-like fixing solution. The film thickness of the liquid layer is controlled. In addition, as the application belt 71, for example, a member such as a seamless nickel belt or a seamless PET file coated with a releasable fluororesin such as PFA is used. In the application means using these rollers or belts, it is desirable that the moving direction of the roller or belt is the same as the moving direction of the resin fine particle layer on the contact surface with the resin fine particles.

  Next, a method and means for controlling the thickness of the foam-like fixing liquid on the contact member surface will be described. The optimum film thickness to be controlled is determined by the average particle diameter of the bubbles formed by the means for forming the foam-like fixing liquid, the pressure applied at the contact portion between the coating means and the medium, and the viscosity of the liquid. As a method of controlling to the determined appropriate liquid film range, a method of scraping off the foam-like fixing liquid by providing a gap with the surface of the coating unit is suitable for the coating unit using a roller-shaped rotating member. For example, scraping with the blade 47 as shown in FIG. 6 or scraping with the wire bar 66 as shown in FIG. 8 is desirable. In the configuration of scraping with the blade 47 in FIG. 6, the roller surface of the application roller 42 and the blade 47 are arranged with a gap close to the appropriate film thickness range. In the configuration of scraping with the wire bar 66 in FIG. 8, the wire diameter is determined so as to be within an appropriate film thickness range. As another thickness control method and means, there is a method of supplying a foam-like fixing liquid so that an appropriate film thickness is obtained on the application surface of the roller-like rotating member. In FIG. 10A, the foam-like fixing solution is held inside the cylindrical stencil member 81, and the foam-like fixing solution is supplied to the surface of the coating member 83 while being pushed out by the press roller 82. At this time, the mesh opening diameter of the cylindrical stencil member 81 is determined so that an appropriate liquid film is formed. FIG. 10B shows an example of supply by the groove roller 84. The groove depth of the groove roller 84 is determined so that an appropriate liquid film is formed. The contact application means for the foam-like fixing solution may be direct stencil application, gravure roller application, rotating wire bar application, etc., in addition to the roller application means. In any of these means, the coating means itself has a mesh, streaks, or uneven shape on the surface, and the amount of the foam-like fixing liquid on the contact surface between the coating surface and the medium can be controlled by controlling the coating amount. The liquid film can be controlled.

  Next, the liquid formulation of the fixing solution of the present invention will be described. As described above, the foam-like fixing solution of the present invention has a structure in which bubbles are contained in a liquid containing a softening agent. The liquid containing the softening agent preferably contains a foaming agent and a foam-increasing agent in order to stably form bubbles and form a foam layer having a uniform bubble size. Moreover, it is desirable to contain a thickener since the bubbles are more stably dispersed in the liquid when the viscosity is higher to some extent. The foaming agent is preferably a surfactant, and higher fatty acid alkali soaps such as Na stearate, Na palmitate and Na myristate are suitable. As the foam increasing agent, a fatty acid alkanolamide type nonionic surfactant is desirable. For example, coconut fatty acid diethanolamide, coconut fatty acid monoethanolamide, lauric acid isopropanolamide and the like are desirable.

  Further, in order to prevent offset, it is desirable that the thickness of the foam-like fixing liquid layer at the application portion is thicker than the thickness of the resin fine particle layer. Further, it is desirable that the bubbles be larger than the resin fine particles in order to make the bubbles easily adhere to the resin fine particles. When the resin fine particles are toner particles, in the dry electrophotographic system, the toner particles are about 4 to 10 μm in size, and the unfixed toner layer on the paper medium is about 10 to 30 μm. The size of the bubbles contained in the liquid is preferably about 20 μm to 100 μm.

  Furthermore, most of the liquid in the fixing solution may be only the softener except for additives such as a foaming agent and a foaming agent. However, if the content of the softening agent in the fixing solution is too large, the resin may be too soft and the adhesive feeling may become strong. Therefore, the fixing solution preferably contains a diluting solvent for diluting the softening agent. The dilution solvent may be oily or aqueous. As a diluting structure, a structure in which a softener is dissolved in a diluting solvent, a structure in which the softening agent is oily and the diluting solvent is aqueous and an O / W emulsion, or a softening agent is oily and the diluting solvent is aqueous and a W / O emulsion is configured. Or, the softening agent may be oily and the diluent solvent may be an oily O / O emulsion.

  Further, in the configuration in which the fixing solution is stored in the high-pressure sealed container, a configuration in which the liquefied gas or the compressed gas is dissolved or dispersed in the liquid containing the softening agent is desirable. As the liquefied gas, aliphatic hydrocarbons such as propane, butane, pentane, hexane and dimethyl ether are suitable. As the compressible gas, nitrogen gas, argon gas, or the like is suitable.

  First, the softening agent softened by dissolving or swelling the resin contains an aliphatic ester. This aliphatic ester is excellent in solubility or swelling property that dissolves or swells at least a part of the resin contained in the toner or the like.

  The softening agent has an acute oral toxicity LD50 of more than 3 g / kg, more preferably 5 g / kg, from the viewpoint of safety to the human body. As aliphatic esters are frequently used as cosmetic raw materials, they are highly safe for the human body.

  Further, the toner is fixed to the recording medium in a device that is frequently used in a sealed environment, and the softener remains in the toner even after the toner is fixed to the recording medium. Preferably does not involve the generation of volatile organic compounds (VOC) and 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.). Aliphatic esters also have the advantage of not causing water contamination.

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

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

Therefore, in the fixing solution of the present invention, preferably, the general formula of the saturated aliphatic ester is
R1COOR2
Wherein R1 is an alkyl group having 11 to 14 carbon atoms, and R2 is a linear or branched alkyl group having 1 to 6 carbon atoms.

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

  Examples of the aliphatic monocarboxylic acid ester that is the above compound include ethyl laurate, hexyl laurate, ethyl tridecylate, isopropyl tridecylate, ethyl myristate, isopropyl myristate, and the like. Many of these aliphatic monocarboxylic acid esters, which are the above compounds, are soluble in oily solvents, but not in water. Therefore, for many of the aliphatic monocarboxylic acid esters that are the above-mentioned compounds, the oil-based solvent has a structure in which the aliphatic monocarboxylic acid ester that is the above-mentioned compound is dissolved, and in the aqueous solvent, for example, the fatty acid that is the above-mentioned compound. A fixing liquid can be obtained by preparing an aqueous phase mainly composed of water and a W / O emulsion or an O / W emulsion using an aromatic monocarboxylic acid ester as an oil phase.

  In the fixing solution of the present invention, preferably, the aliphatic ester includes an aliphatic dicarboxylic acid ester. When the aliphatic ester includes an aliphatic dicarboxylic acid ester, the resin contained in the toner can be dissolved or swollen in a shorter time. For example, in high-speed printing of about 60 ppm, it is desirable that the time until the fixing liquid is applied to the unfixed toner on the recording medium and the toner is fixed on the recording medium is within 1 second. When the aliphatic ester includes an aliphatic dicarboxylic acid ester, the 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. It is possible to be 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 liquid can be reduced.

Therefore, in the fixing solution of the present invention, preferably, the general formula of the aliphatic dicarboxylic acid ester is
R3 _{(COOR4) 2}
R3 is an alkylene group having 3 to 8 carbon atoms, and R4 is a linear or branched alkyl group having 2 to 5 carbon atoms.

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

  Examples of the aliphatic dicarboxylic acid ester which is the above compound include ethylhexyl succinate, dibutyl adipate, diisobutyl adipate, diisopropyl adipate, diisodecyl adipate, diethyl sebacate, dibutyl sebacate and the like. Many of these aliphatic dicarboxylic acid esters, which are the above compounds, are soluble in oily solvents, but not in water. Therefore, for many of the aliphatic dicarboxylic acid esters that are the above-described compounds, the oil-based solvent has a structure in which the aliphatic dicarboxylic acid ester that is the above-mentioned compound is dissolved. In the aqueous solvent, for example, the aliphatic compounds that are the above-mentioned compounds are aliphatic. A fixing solution is obtained by preparing a water phase mainly composed of water and a W / O emulsion or an O / W emulsion using a dicarboxylic acid ester as an oil phase.

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

In the fixing solution of the present invention, preferably, the general formula of the above aliphatic dicarboxylic acid dialkoxyalkyl is:
R5 (COOR6-O-R7) ₂
R5 is an alkylene group having 2 to 8 carbon atoms, R6 is an alkylene group having 2 to 4 carbon atoms, and R7 is 1 to 4 carbon atoms. It is an alkyl group.

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

  Examples of the aliphatic dicarboxylate dialkoxyalkyl which is the above compound include diethoxyethyl succinate, dibutoxyethyl succinate, diethoxyethyl adipate, dibutoxyethyl adipate, diethoxyethyl sebacate and the like. . These aliphatic dicarboxylic acid dialkoxyalkyls are dissolved or dispersed in an oily solvent to form an oil phase, and an aqueous phase mainly composed of water and a W / O emulsion or O / W emulsion are prepared to obtain a fixing solution. Moreover, the structure melt | dissolved in the water phase which has water as a main component may be sufficient.

  The fine particles containing the resin to be fixed are not limited to toner, and any fine particles containing resin may be used. For example, resin fine particles containing a conductive member may be used. Further, the recording medium is not limited to recording paper, and any of metal, resin, ceramics and the like may be used. The form of the recording medium is not limited to a sheet shape, and may be a three-dimensional object having a flat surface and a curved surface.

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

  The oil-based solvent and softening agent preferably have sufficient affinity for the water-repellent treated toner particles. Here, affinity means the degree of extended wetting of the liquid with respect to the surface of the solid when the liquid comes into contact with the solid. That is, it is preferable that the oil-based solvent and the softening agent exhibit sufficient wettability with respect to the water-repellent treated toner. The surface of the toner subjected to water repellency treatment with hydrophobic fine particles such as hydrophobic silica and hydrophobic titanium oxide is covered with methyl groups present on the surfaces of hydrophobic silica and hydrophobic titanium oxide, and is approximately 20 mN / m. Has a surface energy of a degree. In reality, since the entire surface of the water-repellent treated toner is not completely covered with hydrophobic fine particles, the surface energy of the water-repellent treated toner is estimated to be approximately 20 to 30 mN / m. The Therefore, in order to have affinity for the water-repellent toner (having sufficient wettability), the surface tension of the diluting solvent and the softening agent is preferably 20 to 30 mN / m. When such a diluent solvent is oily, for example, fluorine oil, paraffin solvent, olefin solvent, silicone solvent and the like can be mentioned. Among these, a solvent composed of an olefin compound is particularly excellent in that the viscosity can be adjusted by adding a thickener because it is non-volatile even if it has a low viscosity. Of the silicone solvents, dimethyl silicone has an extremely low surface tension and the best affinity with the toner. The oily solvent and softening agent in the present invention are desirably non-volatile. Nonvolatile in the present invention means a state having a boiling point of 260 ° C. or higher under atmospheric pressure. If the boiling point is 260 ° C. or higher, even if the fixing solution is stored in a simple and inexpensive container, the volatilization that causes a reduction in fixing ability and contamination in the image forming apparatus having the fixing device does not occur. When the boiling point is less than 260 ° C., it is necessary to ensure the sealing property of the storage container and the sealing property of the liquid replenishment path to the fixing device, which increases the cost of the device.

  Furthermore, an aqueous solvent as a diluent solvent is highly safe, and an environment-friendly fixing solution can be produced. In the case of using an aqueous solvent, it is preferable that the surface tension is 20 to 30 mN / m by adding a surfactant. In the case of an aqueous solvent, it is desirable to contain a unit price or a polyhydric alcohol. These materials have the advantage of increasing the stability of the bubbles in the foam-like fixing solution and making it difficult to break the bubbles. For example, monohydric alcohols such as cetanol, and polyhydric alcohols such as glycerin, propylene glycol, and 1,3 butylene glycol are desirable.

  When an O / W emulsion or a W / O emulsion is formed with a softener and a diluting solvent, specific dispersants include sorbitan fatty acid esters such as sorbitan monooleate, sorbitan monosterate and sorbitan sesquiolate, Sucrose esters such as sucrose laurate and sucrose stearate are desirable.

  Here, as a method for dispersing the softener in the diluting solvent, for example, a mechanical stirring means such as a homomixer or a homogenizer using a rotary blade, and a means for applying vibration such as an ultrasonic homogenizer can be cited. It is done. In any case, a strong shear stress is added to the diluting solvent softener to disperse.

  In the fixing solution of the present invention, the oily solvent that forms the oil phase in the W / O emulsion, the O / W emulsion, or the O / O emulsion fixing solution preferably contains dimethyl silicone. When the above oil-based solvent contains dimethyl silicone, it has a high affinity particularly for the water-repellent treated toner, and the water-repellent treated toner can be wetted significantly. In other words, dimethyl silicone, which is a silicone solvent, has a low surface tension of about 20 mN / m and has a high affinity for water-repellent treated toner. As a result, when the fixing liquid of the present invention is applied to the water-repellent treated toner on the recording medium, it is possible to reduce the disturbance of the image formed by the water-repellent treated toner. Further, dimethyl silicone is odorless and has high safety for the human body. For this reason, a fixing solution containing dimethyl silicone as an oily solvent can be made into a fixing solution that is safe and odorless to the human body. For example, dimethyl silicone having a viscosity of 20 mPa · sec or more has low volatility, and when a fixer droplet containing dimethyl silicone as an oily solvent is applied to a water-repellent treated toner layer, the toner layer There is almost no disturbance. As a dispersant for an O / O emulsion or W / O emulsion fixing solution using dimethyl silicone as a diluent solvent, polyether-modified silicone or polyol-modified silicone is desirable.

  In addition, the toner fixing device pressurizes the dissolved or swollen toner with a component (softener) that dissolves or swells at least a part of the resin contained in the toner after supplying the fixing liquid in the present invention to the toner. You may have a pair of smoothing roller (hard roller). By pressurizing the dissolved or swollen toner with a pair of smoothing rollers (hard rollers), the surface of the layer of the dissolved or swollen toner can be smoothed to give gloss to the toner. Furthermore, by fixing the dissolved or swollen toner into the recording medium, the fixability of the toner to the recording medium can be improved.

  In the image forming apparatus, a toner image including a resin is formed on a recording medium using the above-described image forming method. Therefore, according to this image forming apparatus, as described above, an image forming method and an image forming method that can more efficiently fix toner onto a recording medium using the foam-like fixing liquid of the present invention, respectively. An apparatus can be provided.

  FIG. 11 is a schematic diagram showing the configuration of the image forming apparatus. The image forming apparatus shown in the figure may be a copying machine or a printer. FIG. 11A is a schematic view of the entire color electrophotographic tandem type image forming apparatus, and FIG. 11B is a configuration of one image forming unit of the image forming apparatus of FIG. FIG. An image forming apparatus 90 shown in FIGS. 11A and 11B has an intermediate transfer belt 91 as a toner image carrier. The intermediate transfer belt 91 is stretched around three support rollers 92 to 94 and rotates in the direction of arrow A in the figure. On the intermediate transfer belt 91, black, yellow, magenta and cyan image forming units 95 to 98 are arranged. Above these image forming units, an exposure device (not shown) is arranged. For example, when the image forming apparatus is a copying machine, each exposure L1 to L4 for reading image information of an original with a scanner and writing an electrostatic latent image on each photosensitive drum according to the image information is performed. Irradiated by an exposure apparatus. A secondary transfer device 99 is provided at a position facing the support roller 94 of the intermediate transfer belt 91 with the intermediate transfer belt 91 interposed therebetween. The secondary transfer device 99 includes a secondary transfer belt 102 that is stretched between two support rollers 100 and 101. As the secondary transfer device 99, a transfer roller may be used in addition to the transfer belt. A belt cleaning device 103 is arranged at a position facing the support roller 92 of the intermediate transfer belt 91 with the intermediate transfer belt 91 interposed therebetween. The belt cleaning device 103 is arranged to remove toner remaining on the intermediate transfer belt 91.

  A recording sheet 104 as a recording medium is guided to a secondary transfer unit by a pair of paper feed rollers 105, and the secondary transfer belt 102 is pressed against the intermediate transfer belt 91 when the toner image is transferred to the recording sheet 104. Thus, the toner image is transferred. The recording paper 104 onto which the toner image has been transferred is conveyed by the secondary transfer belt 102, and the unfixed toner image transferred onto the recording paper 104 is based on image information from an exposure device (not shown). Fixing is performed by a toner fixing device that controls the film thickness of the foam-like fixing liquid. That is, for the unfixed toner image transferred to the recording paper 104, the film thickness of the foam-like fixing liquid layer is controlled based on image information from an exposure device (not shown), for example, a color image or a black solid image. A part (softener) which is provided with the foam-like fixing solution supplied from the toner fixing device and dissolves or swells at least a part of the resin contained in the toner contained in the foam-like fixing solution. As a result, the unfixed toner image is fixed on the recording paper 104.

  Next, the image forming unit will be described. As shown in FIG. 11B, in the image forming units 95 to 98, a charging device 107, a developing device 108, a cleaning device 109, and a charge eliminating device 110 are disposed around the photosensitive drum 106. A primary transfer device 111 is provided at a position facing the photosensitive drum 106 with the intermediate transfer belt 91 interposed therebetween. The charging device 107 is a contact charging type charging device employing a charging roller. The charging device 107 uniformly charges the surface of the photosensitive drum 106 by bringing a charging roller into contact with the photosensitive drum 106 and applying a voltage to the photosensitive drum 106. As the charging device 107, a non-contact charging type charging device using a non-contact scorotron or the like may be used. Further, the developing device 108 causes the toner in the developer to adhere to the electrostatic latent image on the photosensitive drum 106 to visualize the electrostatic latent image. Here, the toners corresponding to the respective colors are made of resin materials colored in the respective colors, and these resin materials are dissolved or swollen by the fixing solution in the present invention. The developing device 108 has a stirring unit and a developing unit (not shown), and the developer that has not been used for development is returned to the stirring unit and reused. The toner concentration in the agitation unit is detected by a toner concentration sensor, and is controlled so that the toner concentration is constant. Further, the primary transfer device 111 transfers the toner visualized on the photosensitive drum 106 to the intermediate transfer belt 91. Here, a transfer roller is employed as the primary transfer device 111, and the transfer roller is pressed against the photosensitive drum 106 with the intermediate transfer belt 91 interposed therebetween. As the primary transfer device 111, a conductive brush, a non-contact corona charger, or the like can be employed. In addition, the cleaning device 109 removes unnecessary toner on the photosensitive drum 106. As the cleaning device 109, a blade having a tip pressed against the photosensitive drum 106 can be used. Here, the toner recovered by the cleaning device 109 is recovered by the developing device 108 and reused by a recovery screw and a toner recycling device (not shown). Further, the static elimination device 110 is constituted by a lamp, and initializes the surface potential of the photosensitive drum 106 by irradiating light.

Next, specific examples of the fixing solution in the present invention will be described.
[Specific Example 1]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 59wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
5 wt%
Penetration agent: Polyether-modified silicone (Toray Dow Corning Silicone SS2802) 1wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Sodium alkyl sulfate 2wt%
pH adjuster: Triethanolamine 1wt%
A solution was prepared by mixing and stirring at the above component ratio.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Liquefied gas (LPG) 5wt%
An O / W emulsion liquid was prepared by mixing in a sealed container having an actuator part for opening to the atmosphere and a nozzle part at the above component ratio and stirring.

<Coating device>
As shown in FIG. 7, a foam-like fixing solution was prepared from a sealed container and supplied to the blade. The gap between the blade and the application roller was set in two ways: 75 μm and 150 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Blade: SUS sheet transport speed: 150 mm / s
Load between pressure roller and application roller: 196N on one side

Then, the fixing solution sprayed from the high-pressure sealed container to form a foam was supplied to the gap between the blade and the coating roller through the tube. The bulk density of the foam-like fixing solution was 0.06 g / cm ³ .

  Here, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating roller to 75 μm, a foam-like fixing solution layer of about 100 μm was formed on the coating roller. As shown in FIG. 12A, from the observation with an optical microscope, the bubbles in the fixing solution are distributed in the range of 30 μm to 100 μm, and the number of bubbles in the vicinity of 70 μm is the largest. It was a layer. On the other hand, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating roller to 150 μm, a foam-like fixing solution layer of about 200 μm was formed on the coating roller. As shown in FIG. 12 (b), from observation with an optical microscope, bubbles in the fixing solution are distributed in a range of 30 μm to 100 μm, and the number of bubbles in the vicinity of 70 μm is the largest. It was a bubble layer.

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 7, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the gap between the blade and the coating roller is 75 μm and the film thickness of the foam-like fixing solution is controlled to 100 μm, that is, in the case of a foam-like fixing solution having a single cell layer, 10 seconds after applying the fixing solution. The toner did not adhere to the waste due to rubbing with the waste. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the gap between the blade and the coating roller is 150 μm and the film thickness of the foam-shaped fixing solution is controlled to 200 μm, that is, in the case of a foam-shaped fixing solution having a plurality of bubble layers, Offset and significant image degradation occurred. As described above, it was confirmed that by fixing the film thickness of the foam-like fixing liquid layer on the application roller within an appropriate range, it is possible to perform fixing with excellent fixing response without occurrence of offset.

[Specific Example 2]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 59wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
5 wt%
Penetration agent: Polyether-modified silicone (Toray Dow Corning Silicone SS2802) 1wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Sodium alkyl sulfate 2wt%
pH adjuster: Triethanolamine 1wt%
A solution was prepared by mixing and stirring at the above component ratio.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Liquefied gas (LPG) 5wt%
The mixture was mixed in a sealed container at the above component ratio, and an O / W emulsion liquid was prepared by stirring.

<Coating device>
As shown in FIG. 7, a foam-like fixing solution was prepared from a sealed container and supplied to the blade. The gap between the blade and the application roller was set to 100 μm and 250 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Blade: SUS sheet transport speed: 150 mm / s
Load between pressure roller and application roller: 196N on one side

Then, the fixing solution was supplied from the sealed container to the stirring roller through the tube and sufficiently stirred to prepare a foam-like fixing solution, which was applied to the coating roller. The bulk density of the foam-like fixing solution was 0.1 g / cm ³ . Moreover, the average size of the bubbles was about 80 μm. When the liquid film was controlled by setting the gap between the blade and the coating roller to 100 μm, a foam-like fixing liquid layer having a thickness of about 130 μm was formed. On the other hand, when the liquid film was controlled by setting the gap between the blade and the coating roller to 250 μm, a foam-like fixing liquid layer of about 300 μm was formed.

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 7, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the gap between the blade and the coating roller was 100 μm and the film thickness of the foam-like fixing solution was controlled to 130 μm, the toner was not rubbed by rubbing with the waste 10 seconds after coating. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the gap between the blade and the coating roller was 250 μm and the film thickness of the foam-like fixer was controlled to 300 μm, an image due to the toner flowed and significant image deterioration occurred.

[Specific Example 3]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 59wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
5 wt%
Penetration agent: Polyether-modified silicone (Toray Dow Corning Silicone SS2802) 1wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Sodium alkyl sulfate 2wt%
pH adjuster: Triethanolamine 1wt%
A solution was prepared by mixing and stirring at the above component ratio.

<Coating device>
As shown in FIG. 6, the fixing solution was taken out from the sealed container, prepared, and stirred with a liquid stirring roller to form a foam-like fixing solution. The gap between the blade and the application roller was set to 50 μm and 100 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Foam-type fixing liquid supply roller and stirring roller: an aluminum roller (φ20) coated with propylene resin
Paper transport speed: 150 mm / s
Load between pressure roller and application roller: 490N on one side

Then, the fixing solution was supplied from the sealed container to the stirring roller through the tube and sufficiently stirred to prepare a foam-like fixing solution, which was applied to the coating roller. The bulk density of the foam-like fixing solution was 0.1 g / cm ³ . Moreover, the average size of the bubbles was about 100 μm. When the film thickness of the foam-like fixing liquid layer was controlled by setting the gap between the blade and the coating roller to 100 μm, a foam-like fixing liquid layer of about 130 μm was formed. On the other hand, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating roller to 50 μm, a foam-like fixing solution layer of about 70 μm was formed.

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 6, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the gap between the blade and the coating roller was 100 μm and the film thickness of the foam-like fixing solution was controlled to 130 μm, the toner was not rubbed by rubbing with the waste 10 seconds after coating. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the gap between the blade and the application roller was 50 μm and the film thickness of the foam-like fixing solution was controlled to 70 μm, toner was offset on the roller surface, resulting in significant image degradation.

[Specific Example 4]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 59wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
5 wt%
Penetration agent: Polyether-modified silicone (Toray Dow Corning Silicone SS2802) 1wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Sodium alkyl sulfate 2wt%
pH adjuster: Triethanolamine 1wt%
A solution was prepared by mixing and stirring at the above component ratio.

<Coating device>
As shown in FIG. 8, a stirring blade was provided in a sealed container, and stirring was performed so as to apply a shearing force to the fixing solution, thereby preparing a foam-like fixing solution. The liquid was supplied with compressed air from a pressure cylinder and supplied to the fixing liquid supply pad via a supply pipe. The wire diameter of the wire bar was set to 0.2 mm and 0.3 mm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Load between pressure roller and application roller: 490N on one side
Paper transport speed: 150 mm / s
Rotation speed of stirring blade: 3000rpm

The bulk density of the foam-like fixing solution was 0.03 g / cm ³ . The size of the bubbles was about 60 μm. A wire bar having a wire diameter of 0.2 mm was brought into contact with the coating roller to scrape off the fixing solution to form a foam-like fixing solution layer of about 100 μm. On the other hand, a configuration was also used in which a wire bar having a wire diameter of 0.3 mm was scraped and a foam-like fixing liquid layer having a thickness of about 300 μm was formed.

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 8, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the film thickness of the foam-like fixing solution was controlled to 100 μm, the toner was not adhered to the waste by rubbing with the waste 10 seconds after application. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the film thickness of the foam-like fixing solution was controlled to 300 μm, an image due to the toner flow flowed and significant image deterioration occurred.

[Specific Example 5]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 59wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
5 wt%
Penetration agent: Polyether-modified silicone (Toray Dow Corning Silicone SS2802) 1wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Sodium alkyl sulfate 2wt%
pH adjuster: Triethanolamine 1wt%
A solution was prepared by mixing and stirring at the above component ratio.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Liquefied gas (LPG) 5wt%
The mixture was mixed in a sealed container at the above component ratio, and an O / O emulsion liquid was prepared by stirring.

<Coating device>
A foam-like fixing solution was applied to the unfixed toner layer by an application belt as shown in FIG. The gap between the blade and the coating belt was set in two ways: 75 μm and 150 μm.
Pressure roller: Aluminum roller (φ30)
Coating belt: 100 μm thick nickel seamless film pressure roller baked with PFA resin and applied roller and coating roller: 196N on one side
Belt nip width of application belt: 10mm
Paper transport speed: 300mm / s

  When the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating belt to 75 μm, a foam-like fixing solution layer of about 100 μm was formed on the coating belt. The size of the bubbles in the foam-like fixing solution was distributed in a range of 30 to 100 μm, the number of bubbles in the vicinity of 70 μm was the largest, and the bubble layer was a single layer. On the other hand, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating belt to 150 μm, a foam-like fixing solution layer of about 200 μm was formed on the coating belt. The size of the bubbles in the foam-like fixing solution was distributed in a range of 30 to 100 μm, the number of bubbles in the vicinity of 70 μm was the largest, and the bubble layer was a plurality of layers.

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, belt application was performed on PPC paper on which a color image of unfixed toner was formed using the fixing device shown in FIG. 9, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the film thickness of the foam-like fixing solution was controlled to 100 μm, the toner was not adhered to the waste by rubbing with a waste 10 seconds after the fixing solution was applied. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the film thickness of the foam-like fixing solution was controlled to 200 μm, most of the toner layer was offset from the coating belt, and significant image deterioration occurred. As described above, it was confirmed that by fixing the film thickness of the foam-like fixing liquid layer on the coating belt to an appropriate range, it is possible to perform fixing with excellent fixing response without occurrence of offset. Furthermore, the fixing member can be applied without offset at a speed twice as high as that of roller application by forming the application member in a belt shape and widening the nip width of the application surface.

[Specific Example 6]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: ion exchange water 53wt%
Softener: Diisobutyl adipate (Higher Alcohol Industry KEK-DiBA) 5 wt%
Penetration agent: polyether modified silicone (Toray Dow Corning Silicone SS2802) 2wt%
Dispersant: POE sorbitan monostearate (Kao Rheodor TW-S120V) 5 wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Isostearyl octyldodecanate 2wt%
pH adjuster: Triethanolamine 1wt%
The components were mixed at the above component ratios and stirred with an ultrasonic homogenizer to prepare an O / W emulsion dispersion.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Liquefied gas (LPG) 5wt%
The mixture was mixed in a sealed container at the above component ratio, and an O / W emulsion liquid was prepared by vibration stirring.

<Coating device>
As shown in FIG. 7, a foam-like fixing solution was prepared from a sealed container and supplied to the blade. The gap between the blade and the application roller was set in two ways: 75 μm and 150 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Blade: SUS sheet transport speed: 150 mm / s
Load between pressure roller and application roller: 196N on one side

Then, the fixing solution sprayed from the high-pressure sealed container to form a foam was supplied to the gap between the blade and the coating roller through the tube. The bulk density of the foam-like fixing solution was 0.06 g / cm ³ .

  Here, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating roller to 75 μm, a foam-like fixing solution layer of about 100 μm was formed on the coating roller. As shown in FIG. 12A, from the observation with an optical microscope, the bubbles in the fixing solution are distributed in the range of 30 μm to 100 μm, and the number of bubbles in the vicinity of 70 μm is the largest. It was a layer. On the other hand, when the film thickness of the foam-like fixing solution layer was controlled by setting the gap between the blade and the coating roller to 150 μm, a foam-like fixing solution layer of about 200 μm was formed on the coating roller. As shown in FIG. 12 (b), from observation with an optical microscope, bubbles in the fixing solution are distributed in a range of 30 μm to 100 μm, and the number of bubbles in the vicinity of 70 μm is the largest. It was a bubble layer.

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 7, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the gap between the blade and the coating roller is 75 μm and the film thickness of the foam-like fixing solution is controlled to 100 μm, that is, in the case of a foam-like fixing solution having a single cell layer, 10 seconds after applying the fixing solution. The toner did not adhere to the waste due to rubbing with the waste. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the gap between the blade and the coating roller is 150 μm and the film thickness of the foam-shaped fixing solution is controlled to 200 μm, that is, in the case of a foam-shaped fixing solution having a plurality of bubble layers, Offset and significant image degradation occurred. As described above, it was confirmed that by fixing the film thickness of the foam-like fixing liquid layer on the application roller within an appropriate range, it is possible to perform fixing with excellent fixing response without occurrence of offset.

[Specific Example 7]
<Prescription of fixer>
◇ Liquid containing softener <Prescription of fixer>
◇ Liquid diluent solvent containing softener: ion exchange water 53wt%
Softener: Diisobutyl adipate (Higher Alcohol Industry KEK-DiBA) 5 wt%
Penetration agent: polyether modified silicone (Toray Dow Corning Silicone SS2802) 2wt%
Dispersant: POE sorbitan monostearate (Kao Rheodor TW-S120V) 5 wt%
Thickener: Propylene glycol 30wt%
Foam enhancer: palm fatty acid diethanolamide 2wt%
Foaming agent: Isostearyl octyldodecanate 2wt%
pH adjuster: Triethanolamine 1wt%
The components were mixed at the above component ratios and stirred with an ultrasonic homogenizer to prepare an O / W emulsion dispersion.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Liquefied gas (LPG) 5wt%
The mixture was mixed in a sealed container at the above component ratio, and an O / W emulsion liquid was prepared by vibration stirring.

<Coating device>
As shown in FIG. 7, a foam-like fixing solution was prepared from a sealed container and supplied to the blade. The gap between the blade and the application roller was set to 100 μm and 250 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Blade: SUS sheet transport speed: 150 mm / s
Load between pressure roller and application roller: 196N on one side

Then, the fixing solution was supplied from the sealed container to the stirring roller through the tube and sufficiently stirred to prepare a foam-like fixing solution, which was applied to the coating roller. The bulk density of the foam-like fixing solution was 0.1 g / cm ³ . Moreover, the average size of the bubbles was about 80 μm. When the liquid film was controlled by setting the gap between the blade and the coating roller to 100 μm, a foam-like fixing liquid layer having a thickness of about 130 μm was formed. On the other hand, when the liquid film was controlled by setting the gap between the blade and the coating roller to 250 μm, a foam-like fixing liquid layer of about 300 μm was formed.

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, the PPC paper on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. 7, and after 10 seconds, the surface of the image was rubbed with a waste cloth. The degree of toner fixing on the PPC paper was determined based on whether toner adhered to the waste.

  As a result, when the gap between the blade and the coating roller was 100 μm and the film thickness of the foam-like fixing solution was controlled to 130 μm, the toner was not rubbed by rubbing with the waste 10 seconds after coating. Further, there was almost no residual liquid feeling on the PPC paper, and almost no curling of the paper occurred. Furthermore, almost no toner offset on the coating roller was observed. On the other hand, when the gap between the blade and the coating roller was 250 μm and the film thickness of the foam-like fixer was controlled to 300 μm, an image due to the toner flowed and significant image deterioration occurred.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and substitutions are possible as long as they are described within the scope of the claims.

Japanese Patent No. 3,290,513 JP 2004-109749 A JP 59-119364 A JP 2004-109747 A

Claims (15)

A fixing device that applies a foam-like fixing liquid to resin fine particles formed on a recording medium by an electrostatic recording process and fixes the resin fine particles to the recording medium,
The foam-like fixing solution contains a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin fine particles, and a foaming agent and a foaming agent.   The fixing solution according to claim 1, wherein the fixing solution contains a diluent solvent for diluting the softener.   The fixing solution according to claim 2, wherein the softening agent is dissolved in the dilution solvent.   The fixing solution according to claim 2, wherein the softening agent is dispersed in the dilution solvent.   The fixing solution according to claim 1, wherein a liquefied gas or a compressed gas is dissolved or dispersed in the fixing solution.   The fixing solution according to claim 1, wherein the softening agent includes an aliphatic ester.   The fixing solution according to claim 6, wherein the aliphatic ester includes a saturated aliphatic ester. The saturated aliphatic ester has the general formula R1COOR2
Including a compound represented by
R1 is an alkyl group having 11 to 14 carbon atoms,
The fixing solution according to claim 7, wherein R 2 is an alkyl group having 1 to 6 carbon atoms.   The fixing solution according to claim 6, wherein the aliphatic ester includes an aliphatic dicarboxylic acid ester. The aliphatic dicarboxylic acid ester has the general formula R3 (COOR4) ₂
Including a compound represented by
R3 is an alkylene group having 3 to 8 carbon atoms,
The fixing solution according to claim 9, wherein R 4 is an alkyl group having 2 to 5 carbon atoms.   The fixing solution according to claim 6, wherein the aliphatic ester contains a dialkoxyalkyl aliphatic dicarboxylate. The dialkoxyalkyl aliphatic dicarboxylate has the general formula R5 (COOR6-O-R7) ₂
Including a compound represented by
R5 is an alkylene group having 2 to 8 carbon atoms,
R6 is an alkylene group having 2 to 4 carbon atoms,
The fixing solution according to claim 11, wherein R 7 is an alkyl group having 1 to 4 carbon atoms.   The fixing solution according to claim 1, wherein the softening agent dilution solvent contains water and a monovalent or polyhydric alcohol.   The fixing solution according to claim 1, wherein the softening agent dilution solvent contains an olefinic compound.   The fixing solution according to claim 1, wherein the diluting solvent for the softening agent includes dimethyl silicone.

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