JP2009288794A - Fixer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixer of resin fine particles which does not disturb the fine particles including resin of toner or the like on a medium such as paper, which quickly fixes the resin fine particles to the medium after applying the fixer to the medium on which the resin fine particles are adhered, and which could be applied in small amounts to the degree in which the resin particles do not produce the feeling that the solution is still remaining on the medium. <P>SOLUTION: A foam-like fixer is generated, and attached onto resin fine particles on the medium to fix the resin fine particles to the medium. The fixer includes a softener which melts or swells at least one part of the resin fine particles and softens the resin fine particles; water; a foaming agent consists of a fatty acid salt; and a foam booster which increases the foaming stability of the foam-like fixer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  An image forming apparatus such as a printer, a facsimile, and a copying apparatus is an apparatus that forms an image including characters and symbols on a recording medium such as paper, cloth, and an OHP sheet 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. 17A, the application roller 1 is used as the contact applying means on the recording medium 2. In the configuration in which the fixing solution is applied to the unfixed toner layer 3, when the thickness of the fixing solution layer 4 on the application roller 1 is thinner than that of the unfixed toner layer 3, the application roller 1 is applied at a position where the application roller 1 is peeled from the recording medium 2. Unfixed toner particles are pulled by the surface tension generated by the liquid film of the fixing solution on the surface of the roller 1, and the toner particles are offset on the surface of the application roller 1, so that the image on the recording medium 2 is greatly disturbed. Conversely, as shown in FIG. 17B, when the thickness of the fixing liquid layer 4 on the coating roller 1 is sufficiently thicker than the unfixed toner layer 3, the coating roller 1 is separated from the recording medium 2 at a position where Since the amount of the liquid is large, the surface tension due to the liquid film on the surface of the coating roller 1 is less likely to act directly on the toner particles, and the toner is not offset on the roller side. However, an excessive amount of the fixing solution flows over the recording medium 2 to cause deterioration of image quality, or a longer drying time and a problem in fixing response. In addition, a noticeable residual liquid feeling (a wet feeling when the paper is touched by hand) occurs on the paper. In addition, when the fixing solution contains water, when the amount of application to a medium containing cellulose such as paper is large, the recording medium such as paper is significantly curled, and the recording medium such as paper in the apparatus in an image forming apparatus or the like There is a risk of paper jams during transport. Therefore, in such a configuration in which the roller is applied with the fixing liquid, the fixing responsiveness is improved, the residual liquid feeling is reduced, and a small amount of the fixing liquid is applied to the toner layer on the paper to prevent the curling and the toner offset to the fixing roller is simultaneously achieved. It is extremely difficult to do. Even when a die coating unit, a blade coating unit, or a wire bar coating unit is used as the contact coating unit, the toner is offset to the contact coating unit by surface tension when the amount of the fixing solution becomes small.

  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 after applying a fixing solution to a medium to which resin fine particles are adhered without disturbing fine particles containing resin such as toner on a medium such as paper. An object of the present invention is to provide a fixing solution of resin fine particles capable of being quickly fixed to a medium of resin fine particles and capable of being applied in a small amount to such an extent that no residual liquid feeling is generated on the medium.

  In order to solve the above problems, the fixing solution of the present invention is a fixing solution for fixing resin fine particles to a medium, and a softening agent that softens resin fine particles by dissolving or swelling at least part of the resin fine particles; It is characterized by containing water, a foaming agent comprising a fatty acid salt, and a foaming agent that enhances foam stability of the foam-like fixing solution. Therefore, it is possible to form a bubble layer that can make the bubbles of the foam-like fixing solution finer, has excellent foam stability, and can further suppress the penetration of the fixing solution into the paper, and can fix the fixing solution onto the paper as the recording medium. The coating amount can be reduced, curling of paper as a recording medium is suppressed, and fixing responsiveness is improved.

  In addition, the fixing solution contains a foaming agent composed of a fatty acid alkanolamide type nonionic surfactant to enhance foam stability, so that the foam coating is fixed on the surface where the contact coating means comes into contact with a recording medium such as paper. It is possible to suppress the bubble breakage of the liquid, and to prevent toner offset due to the liquefied bubble of the fixing solution.

  Furthermore, since the fatty acid salt is composed of a saturated fatty acid salt having 12, 14, 16, 18 carbon atoms alone or in a mixture, the foam plateau region can form a solid foam-like fixing solution, and foam stability can be improved. By increasing the height, it is possible to suppress foam breakage of the foam-like fixing liquid on the surface where the contact coating means contacts the recording medium such as paper, and to prevent toner offset due to liquefaction of the fixing liquid.

  Moreover, when the fatty acid salt contains an unsaturated fatty acid salt having 18 carbon atoms and 1 to 3 double bonds, either alone or in a mixture, the fatty acid salt has an environment with a low temperature of 20 ° C. or less relative to water. It has improved solubility in water, and has excellent foaming properties in a low temperature range from 5 ° C. to 15 ° C. to a high temperature range from 35 ° C. to 45 ° C., and stably performs fixing in a wide environmental temperature range. be able to.

  Furthermore, when the fatty acid salt is a sodium salt, potassium salt or amine salt, solubility in water can be maintained, and fixing can be stably performed in a wide environmental temperature range.

  In addition, it is possible to use a high-pressure sealed container by dissolving or dispersing a gas or an atmospheric component that becomes a gas at atmospheric pressure or lower in the fixing solution, and the fixing solution is in the form of a foam containing the finest and finest bubbles. Making possible.

Furthermore, the softener preferably contains an aliphatic ester. The aliphatic ester preferably contains a saturated aliphatic ester. 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. . Furthermore, the aliphatic ester preferably contains an aliphatic dicarboxylic acid ester. 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 3 to 5 carbon atoms. It is an alkyl group. Further, the aliphatic ester preferably contains a dialkoxyalkyl aliphatic dicarboxylate. Further, 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, the fixing solution contains monovalent or polyhydric alcohols, so that curling of a recording medium such as paper containing cellulose can be suppressed.

  The fixing solution of the present invention has foam stability of a foam-like fixing solution, a softening agent that dissolves or swells at least part of the resin fine particles to soften the resin fine particles, water, a foaming agent composed of a fatty acid salt, and a foam-like fixing solution. Contains a foam enhancer. Therefore, it is possible to form a bubble layer that can make the bubbles of the foam-like fixing solution finer, has excellent foam stability, and can further suppress the penetration of the fixing solution into the paper, and can fix the fixing solution onto the paper as the recording medium. The coating amount can be reduced, curling of paper as a recording medium is suppressed, and fixing responsiveness is improved.

It is a conceptual diagram which shows the force which acts on the toner in the contact surface of an application roller and paper. It is a conceptual diagram which shows the mode of application | coating of the fixing solution of this invention. It is a conceptual diagram which shows the mode of application | coating of a foam-form fixing solution. It is a schematic sectional drawing which shows the mode of permeation | transmission in recording media, such as paper, using the fixing solution containing the fatty acid salt as water and a foaming agent. FIG. 4 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 pressure on a contact surface between a coating roller and a recording medium is low. FIG. 4 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 pressure on a contact surface between a coating roller and a recording medium is high. It is the schematic which shows the layer structural example of the foam-form fixing solution at the time of application | coating in this invention. FIG. 6 is a diagram illustrating a change in the fixing solution after the fixing solution is applied. It is the schematic which shows a mode that a foam-form fixing solution is apply | coated to an application roller by the fixing solution application means in this invention. FIG. 3 is a schematic view showing an example of a foam-like fixing liquid generating means and a foam-like fixing liquid layer film thickness controlling means in the present invention. It is the schematic which shows the other example of the foam-form fixing liquid production | generation means in this invention, and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of the foam-form fixing liquid production | generation means in this invention, and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of the foam-form fixing liquid production | generation means in this invention, and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the other example of the foam-form fixing liquid production | generation means in this invention, and a foam-form fixing liquid layer film thickness control means. It is the schematic which shows the structure of the image forming apparatus which concerns on one embodiment of another invention. 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.

  First, the principle of the present invention will be outlined. In the present invention, the surface tension of the liquid surface is a foam-like liquid containing a large amount of bubbles and has a very low bulk density and a property as a fluid by containing a large amount of bubbles. And the effect of the fluidity inside the liquid is extremely small.

  FIG. 1 is a conceptual diagram showing the force acting on the toner on the contact surface between the application roller and the paper. As shown in the figure, when the fixing liquid 12 is in a liquid form, a strong surface tension acts on the liquid surface of the fixing liquid 12 on the application roller 11 along the roller surface. Furthermore, an internal flow is generated in the fixing liquid layer on the application roller 11 in the roller moving direction. For this reason, when the thickness of the fixing liquid layer on the application roller 11 is a thin layer that is equal to or less than that of the toner layer, the surface tension works so as to pull the unfixed toner particles 13 to the surface of the application roller 11, Further, since the liquid internal flow also works to carry the toner along the roller surface, unfixed toner adheres to the application roller 11 and toner offset occurs. When the fixing liquid layer on the application roller 11 is more than twice as thick as the toner layer, the surface tension of the liquid and the influence of the internal flow are less likely to affect the toner. Reduces the toner offset. On the contrary, it means that the fixing liquid layer needs to be thickened to some extent on the surface of the application roller 11 for uniform application without causing the resin fine particles to be 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, the residual liquid feeling and the curling prevention, which means that it is desirable that the weight of the fixing solution is small. In order to satisfy the condition that the thickness of the fixing solution layer is thick and the layer volume 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. At most, the substantial coating weight can be reduced.

  FIG. 2 is a conceptual diagram showing how the fixing solution of the present invention is applied. In the figure, the same reference numerals as those in FIG. 1 denote the same components. As shown in the figure, the fixing solution 14 in the form of foam and containing sufficient air is a fixing solution having a low bulk density (a value obtained by dividing the weight of the fixing solution by its volume). If a fixing solution is used, even when the fixing solution layer on the application roller 11 is thick and has a large volume, the bulk density is low, so that the substantial mass of the fixing solution adhering to the paper can be reduced. In addition, a small amount of the fixer can be applied to a recording medium such as paper without toner offset, and the object of the present invention can be achieved.

  Further, as shown in FIG. 3 (a), the foam-like fixing liquid 14 formed on the coating roller is broken by contact with a recording medium such as paper, and the fixing liquid is liquefied on the roller. As a result, the effect of creating a form is lost. That is, as shown in FIG. 3B, it is desirable that the foam-like fixing liquid 14 has excellent foam stability on the contact surface between the coating roller 11 and a recording medium such as paper.

  Therefore, according to the present invention, a fatty acid salt known as a surfactant is used as a foaming agent, and the fatty acid salt and water are contained in the fixing solution, so that the contact surface between the coating roller and a recording medium such as paper breaks down. To provide a fixer that resists foam breakage to the extent that it does not liquefy.

  Here, FIG. 4 is a schematic sectional view showing a state of penetration in a recording medium such as paper using a fixing solution containing water and a fatty acid salt as a foaming agent. As shown in FIG. 4A, the liquid fixer 12 quickly penetrates into a recording medium such as paper. However, once in the form of a foam, it has been found that the foam-like fixing liquid 14 is extremely difficult to penetrate into a recording medium such as paper as shown in FIG. When the fixer penetration into a recording medium such as paper is high, the amount of fixer applied increases, but as shown in FIG. 4 (b), a foam containing water and a fatty acid salt as a foaming agent It has been found that the fixing solution in the form of a sheet is extremely effective in reducing the coating amount of the fixing solution because it has low permeability to paper or the like. When another surfactant such as a polyoxyethylene surfactant or sodium lauryl sulfate is used instead of the fatty acid salt as a foaming agent, as shown in FIG. It was found that bubbles were broken one after another on the surface in contact with the recording medium such as paper, and the fixer quickly penetrated into the recording medium such as paper. From these results, the fixing solution containing a surfactant tends to penetrate into a recording medium such as paper in the liquid state due to the low surface tension of the liquid. It has been found that the liquid (mainly water) is held on the bubble wall (plateau boundary), thereby inhibiting the penetration of the liquid into a recording medium such as paper. Furthermore, by using a fatty acid salt as a foaming agent, the foam stability of the foaming agent becomes extremely high, and even if the foam-like fixing solution comes into contact with a recording medium such as paper, it does not easily break, It was found that the penetration of the foam-like fixing solution can be remarkably suppressed.

  Further, paying attention to the fact that the bulk density is reduced by forming the foam in this way, the present applicant has disclosed a technique for applying a foam-like fixing solution to the intermediate transfer belt in the above-mentioned Patent Document 4, A small amount of coating solution was proposed. 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. There is no mention of direct 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.

  Further, as described above, when a fatty acid salt is used as a foaming agent, foam stability is increased, and the foam-like fixing solution is less likely to penetrate into a recording medium such as paper. This is an advantage, but there is a possibility that the foam-like fixing solution does not easily penetrate into the toner layer. If the fixing solution does not penetrate into the toner layer, the fixing solution does not cause the toners to stick to each other, resulting in poor fixing. Therefore, the thickness of the foam-like fixing solution layer on the coating roller and the pressure applied on the contact surface between the coating roller and the recording medium such as paper affect the permeability of the foam-like fixing solution to the toner layer, Furthermore, it has been found that the toner offset to the application roller is affected.

  5 and 6 are enlarged views of a portion where the roller coating surface is in contact with the unfixed resin fine particles in the roller coating means. In both figures, the same reference numerals as those in FIGS. 1 and 2 indicate the same components. 5 shows a case where the pressure applied on the contact surface between the application roller 11 and the recording medium is low, and FIG. 6 shows a case where the pressure is high. Moreover, the bubble diameter of FIG. 5 and FIG. 6 is a case where it is substantially the same, The bubble 15 shown in both figures is a main bubble, Although other bubbles exist, it shall be abbreviate | omitted in drawing. 5A shows an application surface of the application roller 11, and the foam-like fixing liquid 14 has a single-layer structure of bubbles 15. FIG. 5B shows an example in which the bubble layer has two layers. Therefore, the layer thickness of the foam-like fixing solution 14 is thinner in FIG. 5A than in FIG. 5B. As shown in FIG. 5A, when the bubble 15 is a single layer and the applied pressure is small, the bubble itself easily adheres to the application surface of the application roller 11 due to surface tension, and the fixing liquid 12 does not adhere to the resin fine particle layer. It is applied only uniformly, and a part of the resin fine particles are adsorbed by the bubbles 15 and offset to the application surface of the application roller 11. On the other hand, as shown in FIG. 5B, when the foam-like fixing liquid 14 has a multi-layered bubble layer structure on the application surface of the application roller 11, the bubbles 15 to the surface of the unfixed toner 16 having irregularities are formed. The foam-like fixing solution 14 can be easily separated between the layers of the bubbles 15 and can be uniformly applied to the resin fine particle layer as shown in FIG. can do.

  Therefore, for example, when the resin fine particles are toner particles and the medium is a recording medium such as paper, in order to prioritize the load reduction of the recording medium conveyance drive system, the pressure on the contact surface between the coating roller and the recording medium is applied. In order to prevent the unfixed toner from being offset on the application roller when the setting is low, the average size of the generated bubbles is measured in advance, and the number of bubble layers on the application roller is set so that there are multiple layers. If the film thickness of the foam-like fixing solution layer is controlled to be a thickness corresponding to a plurality of bubble layers, a foam-like fixing solution layer composed of a plurality of bubble layers is always formed on the coating roller, Toner offset can be prevented.

  On the other hand, in order to uniformly apply a fixing solution to a recording medium such as high-quality paper that is not necessarily smooth, the pressure on the contact surface between the coating roller 11 and the recording medium is set high (see FIG. As shown in a), the foam-like fixing liquid 14 on the application surface of the application roller 11 has a single-layer structure of bubbles 15. However, since the pressure is large, the bubbles 15 are easily pushed into the uneven resin particle layer. Thus, the bubble layer easily peels off from the application surface of the application roller 11, and the foam-like fixing liquid 14 is uniformly applied to the resin fine particle layer. On the other hand, as shown in FIG. 6B, when the pressure is large even when the foam-like fixing liquid 14 has a multi-layered bubble layer structure on the application surface of the application roller 11, the bubbles 15 are resin. Since the bubble layer is thick while being pressed into the fine particle layer, the fine particle diffusion from the fine particle layer to the bubble layer is likely to occur, the resin fine particle layer is disturbed, or some of the diffused fine particles adhere to the coating roller 11. An offset may occur.

  Therefore, when the pressure on the contact surface between the coating roller and the recording medium is high, the average size of the bubbles is measured in advance, and the bubble layer structure is as thin as possible on the coating roller surface. If the thickness of the liquid layer is controlled so that it becomes a foam-like fixing solution, a liquid film having a bubble layer structure close to a single layer is formed on the coating roller, and toner offset can be prevented under high pressure conditions. In addition, if the bubble layer on the coating roller is too thick, the bubble layer flows at the contact portion between the coating roller and the recording medium, and the resin particles move along the flow. In this case, a problem occurs in which the image flows. Therefore, the problem can be solved by controlling the film thickness of the foam-like fixing liquid layer in a range where the fluidity does not occur.

  As described above, it has been explained that the contact pressure between the application roller and the medium and the film thickness of the foam-like fixing liquid on the application roller are the major factors of toner offset to the application roller and image disturbance. When the thickness of the paper varies depending on the paper type, such as postcard paper or thin renewal paper, the contact pressure between the coating roller and the medium differs. In other words, the contact pressure is higher for cardboard, and the contact pressure is lower when the paper is thinner. For this reason, it is necessary to control the film thickness of the foam-like fixing solution on the coating roller so as to be in the optimum range in accordance with the paper type. In addition, the thickness of the toner layer on the paper varies depending on images such as monochrome, color, characters, and photographs. That is, the thicker the toner layer, the higher the contact pressure, and the thinner the toner layer, the lower the contact pressure. For this reason, it is necessary to control the film thickness of the foam-like fixing liquid on the application roller so as to be in the optimum range based on the image information in accordance with the thickness of the toner layer. In any case, it is not possible to perform good fixing simply by using a foam-like fixing solution, but the application of the foam-like fixing solution according to the contact pressure adjusted by the application conditions such as the paper type and the toner layer thickness. The film thickness control in the means is absolutely necessary.

  As described above, by controlling the film thickness of the foam-like fixing solution layer containing a softening agent, water, and a fatty acid salt as a foaming agent, toner offset and image flow to a contact application unit such as an application roller can be reduced. It is possible to prevent and fix by extremely minute application. That is, the present invention contains a softener that dissolves or swells at least a part of resin fine particles to soften the resin fine particles in the fixing solution, and further uses a fixing agent that contains water and a fatty acid salt as a foaming agent. The resin fine particles are fixed to the medium by applying a fixer to the resin fine particles on the medium by means, and fixed to the fine particles when the fixer is applied to the surface of the resin fine particles on the medium. In the application where the liquid comes into contact, the fixer is in a foam-like form containing bubbles, and the film thickness of the foam-like fixer layer is controlled according to the applied pressure, so that the contact like a coating roller The offset of the resin fine particles to the coating means and the flow of the resin fine particle layer can be prevented, and fixing by extremely fine coating can be achieved. In addition, toner fine particles used in electrophotographic technology are highly effective for the present invention as resin fine particles. By controlling the film thickness of the foam-like fixing liquid layer according to the layer thickness of the resin fine particles, toner offset and image flow can be controlled. Can be prevented.

  FIG. 7 is a schematic view showing an example of a layer structure of a foam-like fixing solution at the time of application in the present invention. The liquid 21 shown in the figure has a foam-like configuration containing a softening agent, water and a fatty acid salt as a foaming agent, and containing bubbles 22 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. 8, when the fixing solution is applied, even if it is applied in a large volume state, 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 in which a large amount of 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. 9 is a schematic view showing a state in which a foam-like fixing solution is applied by a coating roller as a 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. Bubbles are generated by submerging cavitation and air entrainment when shear force is applied. FIG. 10 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. Then, as shown in (a) and (b) of the figure, the roller surface of the coating roller 42 is further optimized from the bubble size and pressure of the foam-like fixing liquid by a blade 47 for controlling the liquid film thickness. The film thickness of the fixed fixing liquid layer is controlled.

  The surface of the agitation roller 43 in FIG. 10 may be flat, but it is desirable to form a groove or anilox on the surface to further agitate the liquid. The liquid film thickness control blade 47 may be in either the counter direction or the tailing direction. Further, a spacer for controlling the gap between the application roller 42 and the blade 47 for controlling the liquid film thickness may be provided.

  As a second method, as shown in FIG. 11, together with a liquid fixing solution containing a softening agent, alkanes which are gaseous components under atmospheric pressure or atmospheric pressure are dispersed in the fixing solution and sealed at atmospheric pressure or higher. A foam-like fixing liquid is prepared by containing a large amount of bubbles in the liquid by expanding the gas when it is put into the airtight container 51 and ejected from the actuator 52 and the nozzle 53 attached to the airtight container 51, and a liquid transport pipe Through the liquid supply port 54, the foam-like fixing liquid is supplied to the nip portion between the coating roller 55 and the blade 56. 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. 12, a stirring blade 61 is used as means for applying a shearing force, and a liquid fixing solution containing a softener and water and a fatty acid salt as a foaming agent is contained in a sealed container 62. A foam-like fixing solution is formed by stirring, high-pressure air is sent from a pressure cylinder 63 to discharge the foam-like fixing solution from the sealed container 62, and the foam-like fixing is applied to the application surface of the application roller 65 by the fixing solution supply pad 64. Supply liquid. Then, as shown in FIGS. 12A and 12B, the thickness of the foam-like fixing solution on the application roller 65 is controlled by the wire bar 66, and the size and pressure of the bubbles in the foam-like fixing solution 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.

  As shown in FIG. 13, the fourth method is a method of applying unfixed toner on a recording medium using an 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 due to the expansion of gas or atmospheric components under atmospheric pressure, and foam-like fixing liquid is contained in the liquid. The foam-like fixing liquid is prepared and supplied from the liquid supply port 54 through the liquid conveyance pipe to the nip portion between the coating belt 71 and the blade 56. 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.

  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 for controlling the liquid film thickness as shown in FIG. 11 or scraping with the wire bar 66 as shown in FIG. 12 is desirable. In the structure of scraping with the blade 47 for controlling the liquid film thickness in FIG. 11, the roller surface of the coating roller 42 and the blade 47 for controlling the liquid film thickness are arranged with a gap close to the appropriate film thickness range. In the configuration of scraping with the wire bar 66 in FIG. 12, the wire diameter is determined so as to be within the 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. 14A, the foam-like fixing liquid is held inside the cylindrical stencil member 81, and the foam-like fixing liquid 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. 14B is an example of supply by the groove roller 84, and 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 will be described. As described above, the foam-like fixing liquid 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.

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

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

  The fatty acid used in the unsaturated fatty acid salt is preferably an unsaturated fatty acid having 18 carbon atoms and 1 to 3 double bonds. 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 fatty acids are used alone or in combination as a foaming agent. Moreover, you may mix and use the said saturated fatty acid salt and unsaturated fatty acid salt as a foaming agent.

  Further, in the saturated fatty acid salt or unsaturated fatty acid salt, when used as a foaming agent for the fixing solution, a sodium salt, potassium salt or amine salt is desirable. It is an important factor as a commercial value of the fixing device that the fixing device can be quickly fixed after the power is turned on. In order to be able to fix in the fixing device, it is essential that the fixing solution is in an appropriate foam form, but the above fatty acid salt is quickly foamed so that it can be fixed after turning on the power. Can be made in a short time. In particular, by using an amine salt, foaming occurs in the shortest time when a shearing force is applied to the fixing solution, and it is possible to easily produce a foam-like fixing solution. It is possible to create a fixable state in the shortest time.

  Furthermore, in order to prevent offset, it is desirable that the thickness of the foam-like fixing liquid layer at the application part 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 5 to 30 μm.

  The dilution solvent is desirably 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 It does not matter. In particular, a structure in which a softening agent is dissolved in a diluting solvent is preferable because of excellent stability during long-term storage.

  Further, in the configuration in which the fixing solution is stored in the high-pressure sealed container, a configuration in which a gas or atmospheric component that becomes a gas under atmospheric pressure is dissolved or dispersed in a liquid containing a softening agent is desirable. As the gas that becomes a gas under atmospheric pressure, aliphatic hydrocarbons such as propane, butane, pentane, hexane, and dimethyl ether are suitable. Nitrogen gas, argon gas, etc. are suitable as the atmospheric component gas. In such a configuration, since a high-pressure gas is used, there is no need to simplify or need a means for supplying the foamed fixing solution to the coating member, and mechanical means for applying a shearing force to the fixing solution or foam. Since it is possible to simplify the means for supplying the fixing solution to the application member, it is easy to reduce the size of the fixing device.

  Moreover, 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.

  Further, 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.

  In addition, 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.).

  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 which are the above-mentioned compounds, in an aqueous solvent, glycols are contained in the fixing solution as a solubilizing agent and are in the form of a solution or a microemulsion.

  In the fixing solution of the present invention, preferably, the aliphatic ester includes an aliphatic dicarboxylic acid ester. When the aliphatic ester includes an aliphatic dicarboxylic acid ester, the resin contained in the toner can be dissolved or swollen in a shorter time. For example, in high-speed printing of about 60 ppm, it is desirable that the time 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 3 to 5 carbon atoms.

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 3 to 5 carbon atoms. In the case of the linear or branched alkyl group, the solubility or swelling property with respect to the resin contained in the toner can be improved. Moreover, the odor index of said compound is 10 or less, and said compound does not have an unpleasant odor and an irritating odor.

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

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

In the fixing solution of the present invention, preferably, the 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. . In an aqueous solvent, these aliphatic dicarboxylic acid dialkoxyalkyls are contained in the fixing solution as a solubilizing agent, and dissolved or microemulsified.

  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. However, it is desirable that the recording medium has permeability to the fixing liquid. If the medium substrate does not have liquid permeability, a medium having a liquid-permeable layer on the substrate is desirable. Further, 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. Examples of suitable binder resins include polystyrene resins, styrene-acrylic copolymer resins, polyester resins, and the like, and examples of the release agent include carbanau wax and polyethylene. And wax components. 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 foam-like fixing solution preferably has a sufficient affinity for the water-repellent treated toner particles. Here, affinity means the degree of extended wetting of the liquid with respect to the surface of the solid when the liquid comes into contact with the solid. That is, it is preferable that the foam-like fixing solution exhibits sufficient wettability with respect to the water-repellent treated toner. The surface of the toner subjected to water repellency treatment with hydrophobic fine particles such as hydrophobic silica and hydrophobic titanium oxide is covered with methyl groups present on the surfaces of hydrophobic silica and hydrophobic titanium oxide, and is approximately 20 mN / m. Has a surface energy of a degree. In reality, since the entire surface of the water-repellent treated toner is not completely covered with hydrophobic fine particles, the surface energy of the water-repellent treated toner is estimated to be approximately 20 to 30 mN / m. The Therefore, in order to have affinity for the water-repellent toner (having sufficient wettability), the surface tension of the foam-like fixing liquid is preferably 20 to 30 mN / m.

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

  In addition, it is also desirable to form an O / W emulsion or a W / O emulsion containing an oil component in order to improve permeability and prevent curling of a medium such as paper, in which case, as a specific dispersant Are preferably sorbitan fatty acid esters such as sorbitan monooleate, sorbitan monosterate and sorbitan sesquioleate, and sucrose esters such as sucrose laurate and sucrose stearate.

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

  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.

  Next, in the image forming apparatus, a toner image including a resin is formed on a recording medium using the image forming method described above. Therefore, it is possible to provide an image forming method and an image forming apparatus capable of fixing toner on a recording medium more efficiently.

  FIG. 15 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. 15A is a schematic view of the entire color electrophotographic tandem type image forming apparatus, and FIG. 15B is a configuration of one image forming unit of the image forming apparatus of FIG. FIG. An image forming apparatus 90 shown in FIGS. 15A and 15B 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 to which the toner image has been transferred is conveyed by the secondary transfer belt 102, and the unfixed toner image transferred to the recording paper 104 is in the form of a foam based on image information from an exposure device (not shown). The toner is fixed by the toner fixing device of the present invention which controls the film thickness of the fixing solution. 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. 15B, 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 and fixing in the present invention will be described.
[Specific Example 1]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 70wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
10 wt%
Thickener: Glycerin 5wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: sodium palmitate 5 wt%
Sodium myristate 3wt%
Sodium stearate 2wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
The dispersant was used to promote the solubility of the softener in the diluent solvent.
First, at the above component ratio, a softening agent was removed at a liquid temperature of 90 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved. The dispersant is an additive for enhancing the solubility of a softener and the like.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Gas that becomes gas under atmospheric pressure (LPG)
5 wt%
The mixture was mixed in a sealed container having an actuator part for opening to the atmosphere and a nozzle part at the above component ratio, and an O / W emulsion liquid in which a gas that became a gas under atmospheric pressure was dispersed by stirring was prepared (the softening agent is Dissolved in fixer).

<Coating device>
As shown in FIG. 11, a foam-like fixing solution was prepared from a sealed container and supplied to the blade. The gap between the blade and the coating roller was implemented in two ways of 25 μm and 40 μm.
Pressure roller: Aluminum roller (φ30)
Application roller: SUS roller (φ30) baked and coated with PFA resin
Blade: SUS sheet transport speed: 200 mm / s
Load between the pressure roller and application roller: 10N and 200N on one side

<Results>
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 0.07 g / cm ³ .

  In FIG. 11, when the gap between the coating roller and the blade is 25 μm and 40 μm, the liquid film thickness and the average cell diameter of the foam-like fixing solution on the coating roller are as shown in Table 1 below. The liquid film thickness was measured with a Doppler laser displacement meter, and the average bubble diameter was measured with an optical microscope enlarged photograph of the liquid film on the application roller, as shown in FIG.

  In addition, during the observation with an optical microscope on the surface of the coating roller, the foam-like fixing solution was hardly broken in a short time (about 1 minute).

  Using an IpsioColor CX8800 (manufactured by Ricoh) as a printer, a PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. The surface was rubbed with a waste cloth, and the degree of toner fixing on the PPC paper was determined based on the presence or absence of toner adhesion to the waste cloth. In addition, the mending tape was brought into close contact with the coating roller after coating, and the presence or absence of toner offset on the coating roller was determined based on the presence or absence of toner adhesion to the mending tape. Further, a four-color gradation pattern was used as an image pattern, and the presence / absence of image disturbance such as image flow or image loss was visually determined. The curl property of the paper was judged as defective when the height from the horizontal surface of the edge of the paper was 20 mm or more.

In addition, the determination criteria of the implementation results were as follows (the same applies to other specific examples and comparative examples).
Fixability (optical density of waste stain): ○: Optical density 0.3 or less Δ: Optical density 0.3 to 0.5 ×: Optical density 0.5 or more Offset property (state of toner adhering to tape visually); ○: Almost no toner adhered △: Thinly adhered toner ×: Excessive toner adhered ○: Almost no image turbulence; ○: Almost no good △: Disturbed on part of image ×: Disturbed on entire surface of curl; ○: 20 mm or less Δ: 20 mm to 30 mm ×: 30 mm or more

  Table 2 below shows the results of evaluating the fixing property, the offset property, the presence / absence of image disturbance, and the curling property of the paper under the foam-like fixing solution conditions shown in Table 1 when the weight on one side of the coating roller is 10N and 200N.

  As can be seen from Table 2, extremely good fixing is possible by appropriately controlling the film thickness of the foam-like fixing liquid on the coating roller according to the pressure applied to the contact surface between the recording medium and the coating roller. .

[Specific Example 2]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 70wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
10 wt%
Thickener: Glycerin 5wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: potassium palmitate 5 wt%
Potassium myristate 3wt%
Potassium stearate 2wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
First, at the above component ratio, a softening agent was removed at a liquid temperature of 90 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Gas that becomes gas under atmospheric pressure (LPG)
5 wt%
The mixture was mixed in a sealed container having an actuator part for opening to the atmosphere and a nozzle part at the above component ratio, and an O / W emulsion liquid in which a gas that became a gas under atmospheric pressure was dispersed by stirring was prepared (the softening agent is Dissolved in fixer).

<Coating device>
As in the first specific example, as shown in FIG. 11, a foam-like fixing solution was prepared from a sealed container and supplied to the blade.

<Results>
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 0.09 g / cm ³ .

  In FIG. 11, when the gap between the coating roller and the blade is set to 25 μm and 40 μm by the same measurement method as in Example 1, the liquid film thickness and average bubble diameter of the foam-like fixing solution on the coating roller are shown in Table 3 below. It became like this.

  In addition, during the observation with an optical microscope on the surface of the coating roller, the foam-like fixing solution was hardly broken in a short time (about 1 minute).

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, the PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. Table 4 below shows the results of evaluating the fixing property, the offset property, the presence / absence of image disturbance, and the curling property of paper under the fixing solution conditions.

  As can be seen from Table 4, extremely good fixing is possible by appropriately controlling the film thickness of the foam-like fixing liquid on the coating roller according to the pressure applied to the contact surface between the recording medium and the coating roller. .

[Specific Example 3]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 66wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
10 wt%
Thickener: Glycerin 5wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: fatty acid amine (palmitic acid raw material 5 wt%, myristic acid raw material 3 wt%, stearic acid raw material 2 wt%, triethanolamine 4 wt%)
14 wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
In the above component ratio, firstly, ion-exchanged water in which triethanolamine is dissolved in advance is heated to a liquid temperature of 90 ° C., and a palmitic acid raw material, a myristic acid raw material, and a stearic acid raw material are added to the fatty acid amine as a foaming agent. Was made. Thereafter, the remaining components excluding the softener were mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Gas that becomes gas under atmospheric pressure (LPG)
5 wt%
The mixture was mixed in a sealed container having an actuator part for opening to the atmosphere and a nozzle part at the above component ratio, and an O / W emulsion liquid in which a gas that became a gas under atmospheric pressure was dispersed by stirring was prepared (the softening agent is Dissolved in fixer).

<Coating device>
As in the first specific example, as shown in FIG. 11, a foam-like fixing solution was prepared from a sealed container and supplied to the blade.

<Results>
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 0.07 g / cm ³ .

  In FIG. 11, when the gap between the coating roller and the blade is set to 25 μm and 40 μm by the same measurement method as in Example 1, the liquid film thickness and average bubble diameter of the foam-like fixing liquid on the coating roller are shown in Table 5 below. It became like this.

  During observation of the coating roller surface with an optical microscope, foam-like fixing solution was hardly broken in a short time (about 1 minute).

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, the PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was coated with a roller using the fixing device shown in FIG. Table 6 shows the results of evaluating the fixing property, the offset property, the presence / absence of image disturbance, and the curling property of paper under the fixing solution conditions.

  As can be seen from Table 6, extremely good fixing is possible by appropriately controlling the film thickness of the foam-like fixing liquid on the coating roller according to the pressure applied to the contact surface between the recording medium and the coating roller. .

[Comparative example]
<Prescription of fixer>
Instead of the fatty acid salt, a polyoxyethylene surfactant which is a nonionic surfactant was used as a foaming agent.
◇ Liquid diluent solvent containing softener: Ion exchange water 79wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
10 wt%
Thickener: Glycerin 5wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: Polyoxyethylene surfactant (Nippon Yushi)
1wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
First, at the above component ratio, a softening agent was removed at a liquid temperature of 25 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved.

◇ 95% by weight of liquid containing softening agent sealed in high-pressure sealed container
Gas (LPG) that becomes gas under atmospheric pressure 5wt%
The mixture was mixed in a sealed container having an actuator part for opening to the atmosphere and a nozzle part at the above component ratio, and an O / W emulsion liquid in which a gas that became a gas under atmospheric pressure was dispersed by stirring was prepared (the softening agent is Dissolved in fixer).

<Coating device>
As in Specific Examples 1 to 3, a foam-like fixing solution was prepared from a sealed container and supplied to the blade as shown in FIG.

<Results>
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 0.20 g / cm ³ .

  In FIG. 11, when the gap between the coating roller and the blade is 25 μm and 40 μm, the liquid film thickness and average bubble diameter of the foam-like fixing solution on the coating roller are as shown in Table 3. Note that the measurement of the liquid film thickness and the average bubble diameter was the same as in Example 1.

  During microscopic observation, bubbles were broken one after another in a short time (about 1 minute), and the foam stability was not good.

  As in Example 1, IpsioColorCX8800 (manufactured by Ricoh) was used as the printer, and the PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. The fixing property, the offset property, the presence / absence of image disturbance, and the curling property of the paper were evaluated under the foam-like fixing solution conditions shown in Table 7 above. The results are shown in Table 8 below.

  As can be seen from Table 8, in the foam-like fixing solution using a foaming agent other than the fatty acid salt, the film thickness of the foam-like fixing solution on the coating roller according to the pressure applied to the contact surface between the recording medium and the coating roller. Even if it is changed, significant offset, image distortion and paper curl occur.

[Specific Example 4]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: Ion exchange water 70wt%
Softener: Diethoxyethyl succinate (Croda Croda DES)
10 wt%
Thickener: Glycerin 5wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: potassium palmitate 5 wt%
Potassium myristate 3wt%
Potassium oleate 2wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
First, at the above component ratio, a softening agent was removed at a liquid temperature of 90 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved.

<Coating device>
After sufficiently stirring with a stirring blade in a sealed container as shown in FIG. 12 to obtain a foam-like fixing solution, the foam-like fixing solution was supplied from the replenishment pad to the coating roller while applying pressure. A wire bar was provided on the coating roller to control the liquid film. As the wire diameter, 0.1 mm and 0.2 mm were used. As the stirring blade, a blade in which wires were bundled like a whipper was used.

<Results>
The stirring rotation speed was 3000 rpm, and the stirring time was 1 minute. At this time, the bulk density of the foam-like fixing solution was 0.10 g / cm ³ .

  In FIG. 12, when the wire diameter of the wire bar is 0.1 mm and 0.2 mm, the liquid film thickness and the average cell diameter of the foam-like fixing solution on the coating roller are as shown in Table 9 below.

  During observation of the coating roller surface with an optical microscope, foam-like fixing solution was hardly broken in a short time (about 1 minute).

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, the PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was applied with a roller using the fixing device shown in FIG. Table 10 below shows the results of evaluating the fixing property, the offset property, the presence / absence of image disturbance, and the curling property of paper under the fixing solution conditions.

  As can be seen from Table 10, extremely good fixing is possible by appropriately controlling the film thickness of the foam-like fixing liquid on the application roller according to the pressure applied to the contact surface between the recording medium and the application roller. .

[Specific Example 5]
<Prescription of fixer>
◇ Liquid diluent solvent containing softener: ion exchange water 58wt%
Softener: Diisobutyl adipate (High Alcohol Industry KAK-DiBA) 7wt%
Thickener: Glycerin 20wt%
Foam enhancer: palm fatty acid diethanolamide (comicado DEA)
2wt%
Foaming agent: potassium palmitate 5 wt%
Potassium myristate 3wt%
Potassium oleate 2wt%
Dispersant: POE (20) lauryl sorbitan (Kao Leodol TW-S120V) 2 wt%
Polyethylene glycol monostearate (Kao Emanon 3199) 1wt%
First, at the above component ratio, a softening agent was removed at a liquid temperature of 90 ° C. and mixed and stirred to prepare a solution. Next, a softener was mixed to prepare a fixer solution (stock solution before forming) in which the softener was dissolved.

<Coating device>
After sufficiently stirring with a stirring blade in a sealed container as shown in FIG. 12 to obtain a foam-like fixing solution, the foam-like fixing solution was supplied from the replenishment pad to the coating roller while applying pressure. A wire bar was provided on the coating roller to control the liquid film. As the wire diameter, 0.1 mm and 0.2 mm were used. As the stirring blade, a blade in which wires were bundled like a whipper was used.

<Results>
The stirring rotation speed was 3000 rpm, and the stirring time was 1 minute. At this time, the bulk density of the foam-like fixing solution was 0.12 g / cm ³ .

  In FIG. 12, when the wire diameter of the wire bar was 0.1 mm and 0.2 mm, the liquid film thickness and the average cell diameter of the foam-like fixing solution on the coating roller were as shown in Table 11 below.

  During observation of the coating roller surface with an optical microscope, foam-like fixing solution was hardly broken in a short time (about 1 minute).

  Using IpsioColorCX8800 (manufactured by Ricoh) as a printer, the PPC paper (Ricoh T-6200) on which a color image of unfixed toner was formed was coated with a roller using the fixing device shown in FIG. Table 12 below shows the results of evaluating the fixing property, the offset property, the presence / absence of image disturbance, and the curling property of paper under the fixing solution conditions.

  As can be seen from Table 12, extremely good fixing is possible by appropriately controlling the film thickness of the foam-like fixing liquid on the application roller according to the pressure applied to the contact surface between the recording medium and the application roller. .

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

11, 32, 42, 55, 65; coating roller, 12, 20; fixing solution,
13; unfixed toner particles; 14, 33; foam-like fixing liquid;
15, 22; bubbles, 16; unfixed toner, 21; liquid,
31; resin fine particles, 41; fixing solution supply roller, 43; stirring roller,
44; Fixing liquid sealed container, 45; Liquid conveying pipe, 46, 54; Liquid supply port,
47, 56; blade, 51, 62; sealed container, 52; actuator,
53; nozzle, 61; stirring blade, 63; pressure cylinder,
64; fixer replenishment pad; 66; wire bar; 71; coating belt;
81; cylindrical stencil member, 82; press roller, 83; coating member,
84; Groove roller, 90; Image forming apparatus.

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

Claims (14)

A fixer that generates a fixer in a foam form, applies the generated fixer to the resin fine particles on the medium, and fixes the resin fine particles to the medium,
The fixing solution comprises a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin fine particles, a foaming agent composed of water and a fatty acid salt, and foam stability of the foam-like fixing solution. A fixing solution comprising a foam-enhancing agent for enhancing the viscosity.   The fixing solution according to claim 1, wherein the foam increasing agent contains a fatty acid alkanolamide type nonionic surfactant.   The fixing solution according to claim 1, wherein the fatty acid salt is a single or mixture of saturated fatty acid salts having 12, 14, 16, and 18 carbon atoms.   2. The fixing solution according to claim 1, wherein the fatty acid salt contains a single or mixture of unsaturated fatty acid salts having 18 carbon atoms and 1 to 3 double bonds.   The fixing solution according to claim 1, wherein the fatty acid salt is a sodium salt, a potassium salt, or an amine salt.   6. The fixing solution according to claim 1, wherein the fixing solution contains alkanes that are gaseous under atmospheric components or atmospheric pressure in a sealed state at atmospheric pressure or higher. Fixer.   The fixing solution according to claim 1, wherein the softening agent includes an aliphatic ester.   The fixing liquid according to claim 7, 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,
9. The fixing solution according to claim 8, wherein R2 is an alkyl group having 1 to 6 carbon atoms.   The fixing solution according to claim 7, 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 10, wherein R 4 is an alkyl group having 3 to 5 carbon atoms.   The fixing solution according to claim 7, 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 12, wherein R 7 is an alkyl group having 1 to 4 carbon atoms.   The fixing solution according to claim 1, wherein the fixing solution contains monohydric or polyhydric alcohols.

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