JP2010113078A - Fixing solution, fixing method, fixing device, image-forming method, and image-forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin microparticle-based fixing solution preventing the decomposition of a softener it contains, is changed into foam so that it is very low in density to perform quick fixation of resin microparticles to a medium, such as a paper sheet, to which the resin microparticles such as a toner adhere, after it is applied to the medium, without disturbing the resin microparticles on the medium; and further enables its very small amount of application to the medium, to such a degree that a person does not feel that it remains on the medium: and to provide a fixing method, a fixing device, an image-forming method, and an image-forming device which all use the fixing solution. <P>SOLUTION: The fixing solution contains a softener which dissolves and swells at least parts of a resin to soften resin microparticles which contain the resin; an anionic surfactant; an ascorbic acid compound; and a solvent. Preferably, the softener is an ester compound, and the anionic surfactant is a 12-18C fatty acid salt. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fixing solution for fixing resin fine particles such as toner on a medium, a fixing method and a fixing device, and an image forming method and an image forming device.

  Image forming apparatuses such as printers, facsimile machines, and copying machines are apparatuses that form images including characters and symbols on recording media such as paper, cloth, and OHP sheets based on image information. 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 an organic compound that can dissolve or swell toner and is insoluble or hardly soluble in water is dispersed and mixed in water is used. There has been proposed a toner wet fixing method in which a toner is dissolved or swollen by spraying or dripping from the surface of an object to be fixed disposed at a predetermined position, and then the object to be fixed is dried (see Patent Document 1).

However, in the wet fixing method of Patent Document 1, since 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, a large amount of fixing agent is not fixed. When applied to toner, a recording medium such as transfer paper (non-fixed material) absorbs moisture of the fixing agent, and wrinkles and curls are generated on the recording medium. 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 in an oil-based solvent has been proposed as a fixing solution that does not repel water-repellent unfixed toner.
For example, Patent Document 2 discloses that a material that dissolves or swells a resin component constituting a toner is diluted (dissolved) with non-volatile dimethyl silicone as a dilute solution (solvent) such as an aliphatic dibasic acid ester. ) Fixers 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 has been proposed in which 8 parts by volume to 120 parts by volume of silicone oil are mixed with 100 parts by volume of a solvent that is dissolved and compatible with silicone oil. Such an oil-based fixing solution contains an oil-based solvent having a high affinity with the water-repellent-treated unfixed toner, so that the toner is dissolved or swollen without repelling the water-repellent-treated unfixed toner, The toner can be fixed on the recording medium.

  However, in Patent Documents 1 to 3, the fixing liquid is applied to the unfixed toner layer. However, as shown in FIGS. 1A and 1B, a recording medium 82 using an application roller 81 as contact applying means. In the configuration in which the fixer is applied to the upper unfixed toner layer 83, when the fixer layer 84 on the application roller 81 is thinner than the unfixed toner layer 83 in order to apply a small amount of fixer to the recording medium 82, At the position where the application roller 81 is separated from the recording medium 82, unfixed toner particles are pulled by the surface tension generated by the liquid film of the fixing liquid on the surface of the application roller 81, and the toner particles are offset on the surface of the application roller 81. The image on the recording medium 82 is greatly disturbed.

Conversely, as shown in FIGS. 1A and 1B, when the thickness of the fixing liquid layer 84 on the application roller 81 is sufficiently thicker than the unfixed toner layer 83, the liquid at the position where the application roller 81 is separated from the recording medium 28. Since the amount is large, the surface tension due to the liquid film on the surface of the coating roller 81 is less likely to act directly on the toner particles, and the toner is not offset on the roller side, but since a large amount of fixing liquid is applied to the paper surface, Excess fixer causes the image to flow over the recording medium 2 and 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 medium such as paper curls remarkably, and the medium such as paper in the apparatus in the image forming apparatus is conveyed. There is a risk of paper jam.
Therefore, in such a configuration in which the roller application 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, reduce the residual liquid feeling, and prevent curling. 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, toner adheres to the contact coating unit due to surface tension, and image deterioration occurs.

  As described above, the conventional fixer formulation using the contact coating means can achieve both the application of a small amount of the fixer to the toner layer on the paper and the uniform application of the toner image without any disturbance in order to improve the fixing response. Extremely difficult. Further, the present invention is not limited to the toner on the recording medium, and is a problem that occurs in any case in which the liquid fixing liquid is applied to the resin fine particle layer on the medium.

  Therefore, in order to solve these problems, by adding a foam-like fixing solution to fine particles containing resin such as toner on a medium such as paper, the resin fine particle layer on the medium is not disturbed, and After applying the fixing solution to the medium to which the resin fine particles are adhered, the resin fine particles are quickly fixed to the medium, and furthermore, it is possible to apply a small amount so that no residual liquid feeling is generated on the medium (see Patent Documents 4 and 5). )

However, since the fatty acid ester as a softening agent used in the fixing solution of Patent Document 4 reacts with water contained in the fixing solution and gradually decomposes, the fixing performance gradually decreases, There is a problem that fixing failure occurs. In addition, the decomposition product of the softening agent may lower the foaming property and foam stability of the fixing solution, so that the foam density of the foamy fixing solution gradually increases, the amount of fixing solution applied increases, and the residual solution There is a problem of feeling and curling.
Further, the fatty acid ester as a softening agent used in the fixing solution of Patent Document 5 is accelerated in its reaction with water due to the presence of the fatty acid amine salt contained in the fixing solution, so that the fixing performance decreases with time. There is a problem that the foaming property and foam stability are remarkably lowered over time.

In addition, it is already known that ester compounds are gradually hydrolyzed by water, and attempts have been made in the pharmaceutical and cosmetic fields to suppress hydrolysis of esters in water compositions containing ester compounds. For example, Patent Document 6 discloses that in a cationic surfactant composition (softener composition) containing a cationic surfactant having an ester bond and water, at least one of a water-soluble alkali metal salt and a water-soluble alkaline earth metal salt. A method for suppressing hydrolysis of a cationic surfactant having an ester bond by adding a seed has been proposed.
Patent Document 7 proposes a method for suppressing hydrolysis of a polyhydric alcohol fatty acid ester by adding an alkyl polyglucoside to an aqueous cleaning composition containing the polyhydric alcohol fatty acid ester.
In addition, in Patent Document 8, an ophthalmic solution containing an ester-based nonionic surfactant, glycyrrhizic acid or a salt thereof, and an ester-based nonionic surfactant based on glycyrrhizic acid or a salt thereof by adding cyclodextrin or a derivative thereof. A method for suppressing the hydrolysis of the agent has been proposed.

  However, even if the hydrolysis inhibitors of ester compounds described in Patent Documents 6 to 8 are added to the fixing solutions of Patent Documents 4 and 5, the softening agent decomposition is suppressed and the foaming of the fixing solution is caused. Obviously, foam stability and foam stability cannot be achieved.

  Therefore, the fixing solution in which the progress of the decomposition of the softening agent is foamed to a very low density, and the fixing solution is applied to the medium to which the resin fine particles are adhered without disturbing the resin fine particles such as toner on the medium such as paper. After application, the resin fine particles are quickly fixed on the medium, and furthermore, a small amount of application can be applied so that no residual liquid sensation is generated on the medium. At present, it is desired to provide a fixing method and a fixing device, and an image forming method and an image forming apparatus.

Japanese Patent No. 3290513 JP 2004-109749 A JP 59-119364 A JP 2007-219105 A JP 2008-058550 A Japanese Patent Laid-Open No. 10-251972 JP-A-7-173490 Japanese Patent No. 3597239 Ishii Ikuo, “Engineering of Bubbles”, first edition, Techno System Co., Ltd., published on March 25, 2005, p. 489

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, according to the present invention, the fixing solution in which the progress of the decomposition of the softener is suppressed to a very low density, and the resin fine particles are adhered without disturbing the resin fine particles such as toner on a medium such as paper. After the fixing solution is applied to the medium, the resin fine particles are quickly fixed on the medium, and furthermore, a small amount of coating can be applied so that no residual liquid feeling is generated on the medium. It is an object of the present invention to provide a fixing method and a fixing device using a fixing liquid, and an image forming method and an image forming apparatus.

Means for solving the problems are as follows. That is,
<1> A softening agent that softens resin fine particles containing the resin by dissolving or swelling at least part of the resin, an anionic surfactant, an ascorbic acid compound, and a solvent. It is a fixing solution.
In the fixing solution described in <1>, by containing an ascorbic acid compound in the fixing solution, the decomposition of the softening agent is suppressed, and the storage stability of the fixing solution is increased. Further, even if an ascorbic acid compound is contained in the fixing solution, the foaming property by the anionic surfactant is not inhibited. Moreover, the foam stability of the produced | generated foam is not reduced. Therefore, it is possible to easily produce a foam-like fixing solution having a very short foaming time from the solution to a desired foam density and excellent foam stability.
<2> The fixing solution according to <1>, wherein the softening agent is an ester compound.
In the fixing solution described in <2>, since the ester compound as a softening agent has a high softening ability of resin fine particles, the resin fine particles can be quickly fixed to a medium.
<3> The fixing solution according to <2>, wherein the ester compound is an aliphatic ester.
In the fixing solution according to <3>, since the ester compound is an aliphatic ester, the foaming property by the anionic surfactant is not inhibited.
<4> The fixing solution according to <2>, wherein the ester compound is a carbonate ester.
In the fixing solution according to <4>, since the ester compound is a carbonate, the foaming property by the anionic surfactant is not inhibited even at a high concentration.
<5> The fixing solution according to any one of <1> to <4>, wherein the anionic surfactant is a fatty acid salt having 12 to 18 carbon atoms.
In the fixing solution according to <5>, since the fatty acid salt having 12 to 18 carbon atoms as the anionic surfactant is excellent in foaming property, a foamy fixing solution having a desired foam density can be obtained in a very short time. It can be produced.
<6> The fixing solution according to <5>, wherein the fatty acid salt is any one of a fatty acid sodium salt, a fatty acid potassium salt, and a fatty acid amine salt.
In the fixing solution according to <6>, when the fatty acid salt is a fatty acid sodium salt, a fatty acid potassium salt, or a fatty acid amine salt, the foam stability is excellent, and fixing with a stable minute coating amount is possible.
<7> Any one of <1> to <6>, wherein the ascorbic acid compound is any one selected from ascorbic acid, sodium ascorbate, trisodium ascorbate 2-phosphate, and 2-glucoside ascorbate The fixing solution described in 1.
In the fixing solution according to <7>, any one selected from ascorbic acid, sodium ascorbate, trisodium ascorbate 2-phosphate, and 2-glucoside ascorbate has an effect of inhibiting decomposition of the softener. Since it is high, the long-term stability of the fixing solution is dramatically increased.
<8> A foam-like fixing solution generating step for producing a foam-like fixing solution by foaming the fixing solution according to any one of <1> to <7>,
A film thickness control step for controlling the film thickness of the foam-like fixer film applied on the contact surface of the foam-like fixer application means to a desired thickness;
And a foaming fixing solution applying step of applying a foamy fixing solution film controlled to the desired thickness to the resin fine particle layer on the medium.
In the fixing method according to <8>, the fixing solution of the present invention is foamed, the foamed fixing solution is formed on the contact imparting surface with a desired thickness, and the foamed fixing solution film having a desired thickness is formed. Is applied to the resin fine particles on the medium to fix the resin fine particles on the medium, the rise time of the fixing device can be shortened, and the fixing can be stably performed with a small amount of coating.
<9> A foam-like fixing solution generating unit that foams the fixing solution according to any one of <1> to <7> to generate a foam-like fixing solution;
A foam-like fixing solution applying means for applying the foam-like fixing solution to a resin fine particle layer on a medium, and having a curved surface portion at least in part;
And a film thickness control means for controlling the film thickness of the foam-like fixing liquid film applied on the contact surface of the foam-like fixing liquid application means.
In the fixing device according to <9>, the foamed fixing solution is generated by the foamed fixing solution generating unit that generates the foamed fixing solution. A foam-like fixing liquid film is applied to the resin fine particle layer on the medium by the foam-like fixing liquid applying means. The film thickness control means controls the film thickness of the foam fixing liquid film on the contact surface of the foam fixing liquid applying means. As a result, the rise time can be shortened and the fixing can be stably performed with a small amount of coating.
<10> An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using a developer including resin fine particles containing a resin and a colorant. An image forming method comprising: a developing step for forming a visible image; a transfer step for transferring the visible image to a recording medium; and a fixing step for fixing the transferred image transferred to the recording medium. ,
The image forming method is characterized in that the fixing step is performed by the fixing method according to <8>.
In the image forming method according to <10>, since the fixing method of the present invention is used as a fixing step, the rise time can be shortened, and fixing can be stably performed with a small amount of coating. It is possible to form an image without fixing failure on the medium.
<11> An electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a resin containing a resin and a colorant. Developing means for developing with a developer containing fine particles to form a visible image; Transfer means for transferring the visible image to a recording medium; Fixing means for fixing the transferred image transferred to the recording medium; An image forming apparatus comprising:
An image forming apparatus using the fixing device according to <9> as the fixing unit.
In the image forming apparatus according to <11>, since the fixing device according to the present invention is used as a fixing unit, fixing failure and a tacky fixing are not caused, and fixing reliability is improved. Further, since the application of the extra fixing solution is reduced, the consumption of the fixing solution can be reduced, and extremely low power fixing can be performed without heating as compared with the conventional case.

According to the fixing solution of the present invention, the fixing solution that suppresses the progress of the decomposition of the softening agent is foamed so as to have a very low density, and the resin fine particles are dispersed without disturbing resin fine particles such as toner on a medium such as paper. After the fixing liquid is applied to the adhered medium, the resin fine particles are quickly fixed to the medium, and furthermore, it is possible to apply a minute amount to the extent that a residual liquid feeling does not occur on the medium.
According to the fixing method of the present invention, since the fixing solution of the present invention is used in the form of foam, the rise time of the fixing device can be shortened, and the fixing can be stably performed with a small amount of coating.
According to the fixing device of the present invention, by using the fixing solution of the present invention in the form of foam, the rise time of the fixing device can be shortened, and the fixing can be stably performed with a small amount of coating.
According to the image forming method of the present invention, since the fixing method of the present invention is included, the rise time can be shortened, the image can be stably fixed with a small amount of coating, and the image does not have poor fixing on a medium such as paper. Formation is possible.
According to the image forming apparatus of the present invention, by using the fixing device of the present invention, fixing with a poor fixing or tackiness is not caused, fixing reliability is improved, and extra fixing liquid is applied. Therefore, it is possible to reduce the consumption of the fixing solution, and it is possible to perform fixing at an extremely low power compared to the conventional case without heating.

(Fixing solution)
The fixing solution of the present invention contains a softener, an anionic surfactant, an ascorbic acid compound, and a solvent, and further contains other components as necessary.

In the present invention, as shown in FIG. 2, the fixing solution is made of a foam-like fixing solution 14 composed of foam by a foam-like fixing solution generating means to be described later. 11 can be thickened, and furthermore, the influence of the surface tension of the fixing solution can be suppressed, so that offset of resin fine particles to the coating roller 11 can be prevented.
Further, when the average particle size of the resin fine particles is about 5 μm to 10 μm, the foamy fixing solution 14 is used to apply the foamy fixing solution 14 to the resin fine particle layer 13 without disturbing the resin fine particle layer 13 on the recording medium 12. The bubble diameter range is preferably 5 μm to 50 μm. As shown in FIG. 3, the foam-like fixing solution 20 composed of bubbles 22 includes a liquid film boundary (hereinafter sometimes referred to as a plateau boundary) 21 that separates the bubbles 22.

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

The softening agent, from the viewpoint of safety for human bodies, it is preferable that the acute oral toxicity LD ₅₀ is greater than 3 g / kg, and more preferably 5 g / kg or more. The fatty acid ester has high safety to the human body, as is often used as a cosmetic raw material.

  Further, the fixing of the toner as the resin fine particles to the recording medium is performed by an apparatus frequently used in a sealed environment, and the softening agent remains in the toner even after the toner is fixed on the recording medium. It is preferable that the toner is not fixed with volatile organic compounds (VOC) and unpleasant odor. That is, it is preferable that the softener does not contain a volatile organic compound (VOC) and a substance that causes an unpleasant odor. The aliphatic ester has a high boiling point and low volatility and does not have an irritating odor as compared with 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 (substance odor is felt by 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.

  The aliphatic ester includes a saturated aliphatic ester. When the aliphatic ester contains a saturated aliphatic ester, the storage stability (resistance to oxidation, hydrolysis, etc.) of the softener can be improved. In addition, the saturated aliphatic ester is 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 presumably 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 includes a compound represented by R ¹ COOR ² , and R ¹ is an alkyl group having 11 to 14 carbon atoms. , R ² is a linear or branched alkyl group having 1 to 6 carbon atoms. If the number of carbon atoms of R ¹ and R ² is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability is lowered.

That is, the saturated aliphatic ester includes a compound represented by the general formula R ¹ COOR ² , R ¹ is an alkyl group having 11 to 14 carbon atoms, and R ² has 1 to 6 carbon atoms. In the case of the following linear or branched alkyl group, the solubility or swelling of the resin contained in the toner can be improved. Moreover, the odor index of the compound represented by the general formula R ¹ COOR ² is 10 or less, and the compound does not have an unpleasant odor or an irritating odor.

  Examples of the aliphatic monocarboxylic acid ester include ethyl laurate, hexyl laurate, ethyl tridecylate, isopropyl tridecylate, ethyl myristate, isopropyl myristate, and the like. Many of these aliphatic monocarboxylic acid esters are soluble in oily solvents but not in water. Therefore, for most of the aliphatic monocarboxylic acid esters, 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.

  The aliphatic ester preferably contains an aliphatic dicarboxylic acid ester. When the aliphatic ester contains an aliphatic dicarboxylic acid ester, the resin contained in the toner can be dissolved or swollen in a shorter time. For example, in high-speed printing of about 60 ppm, it is preferable that the time until the 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 contains an aliphatic dicarboxylic acid ester, the time required for fixing the toner to the recording medium by applying a fixing solution to the unfixed toner or the like on the recording medium is within 0.1 seconds. It becomes possible to. Furthermore, since the resin contained in the toner can be dissolved or swollen by adding a smaller amount of the softening agent, the content of the softening agent contained in the fixing solution can be reduced.

Therefore, in the fixing solution of the present invention, preferably, the general formula of the aliphatic dicarboxylic acid ester includes a compound represented by R ³ (COOR ⁴ ) ₂ , and R ³ has 3 to 8 carbon atoms. An alkylene group, and R ⁴ is a linear or branched alkyl group having 3 to 5 carbon atoms. If the number of carbon atoms in R ³ and R ⁴ is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability decreases.

That is, the aliphatic dicarboxylic acid ester includes a compound represented by the general formula R ³ (COOR ⁴ ) ₂ , R ³ is an alkylene group having 3 to 8 carbon atoms, and R ⁴ is a carbon number. When is a straight chain or branched alkyl group having 3 or more and 5 or less, the solubility or swelling property with respect to the resin contained in the toner can be improved. In addition, the odor index of the compound represented by the general formula R ³ (COOR ⁴ ) ₂ is 10 or less, and the compound does not have an unpleasant odor or an irritating odor.

  Examples of the aliphatic dicarboxylic acid ester include 2-ethylhexyl succinate, dibutyl adipate, diisobutyl adipate, diisopropyl adipate, diisodecyl adipate, diethyl sebacate, and dibutyl sebacate. Many of these aliphatic dicarboxylic acid esters 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 of the present invention, it is preferable that the aliphatic ester contains a dialkoxyalkyl aliphatic dicarboxylate. When the aliphatic ester contains an aliphatic dicarboxylate dialkoxyalkyl, the fixability of the toner to the recording medium can be improved.

In the fixing solution of the present invention, preferably, the general formula of the aliphatic dicarboxylic acid dialkoxyalkyl includes a compound represented by R ⁵ (COOR ⁶ —O—R ⁷ ) ₂ , and R ⁵ has a carbon number. An alkylene group having 2 to 8 carbon atoms, R ⁶ is an alkylene group having 2 to 4 carbon atoms, and R ⁷ is an alkyl group having 1 to 4 carbon atoms. If the number of carbon atoms of R ⁵ , R ⁶ and R ⁷ is less than the desired range, odor is generated, and if it is greater than the desired range, the resin softening ability is lowered.

That is, the aliphatic dicarboxylic acid dialkoxyalkyl includes a compound represented by the general formula R ⁵ (COOR ⁶ —O—R ⁷ ) ₂ , and R ⁵ is an alkylene group having 2 to 8 carbon atoms. , R ⁶ is an alkylene group having 2 or more and 4 or less carbon atoms, and R ⁷ is an alkyl group having 1 or more and 4 or less carbon atoms. Can be improved. In addition, the odor index of the compound represented by the general formula R ⁵ (COOR ⁶ —O—R ⁷ ) ₂ is 10 or less, and the compound does not have an unpleasant odor or an irritating odor.

  Examples of the aliphatic dicarboxylate dialkoxyalkyl include diethoxyethyl succinate, dibutoxyethyl succinate, dicarbitol succinate, dimethoxyethyl adipate, diethoxyethyl adipate, dibutoxyethyl adipate, and diethoxyethyl sebacate. Etc. When these aliphatic dicarboxylic acid dialkoxyalkyls are used in an aqueous solvent, glycols are included in the fixing solution as a dissolution aid, if necessary, to form a solution or microemulsion.

  Examples of the carbonate ester include ethylene carbonate, propylene carbonate (propylene carbonate), glycerol 1,2-carbonate, 4-methoxymethyl-1,3-dioxolan-2-one, and the like.

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

  0.5 mass%-50 mass% are preferable, and, as for content of the said softener, 5 mass%-40 mass% are more preferable. When the content is less than 0.5% by mass, the effect of dissolving or swelling the resin contained in the toner may be insufficient. When the content exceeds 50% by mass, the resin is included in the toner for a long time. There is a possibility that the fluidity of the resin cannot be lowered and the fixing toner layer has adhesiveness.

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

-Ascorbic acid compound-
The fixing solution of the present invention contains an ascorbic acid compound (ascorbic acid or a derivative thereof) in order to suppress decomposition of the softener. Since the softener has an ester group, it gradually reacts with water and is hydrolyzed. However, if a fatty acid amine salt that is a foaming agent is present in the fixing solution, the fatty acid amine salt acts catalytically. The reaction between the softener and water is accelerated. On the other hand, ascorbic acid or a derivative thereof has a molecular structure that can be stabilized by delocalizing electrons between a C═C double bond and a carbonyl group. Intermolecular action on the water and inhibits the catalytic action of the hydrolysis reaction with fatty acid amine salts. Thereby, hydrolysis of a softener can be suppressed. In addition, since the ascorbic acid or its derivative and the fatty acid amine salt have an electrically stable structure, the foamability and foam stability of the fixing solution are not lowered.

  Examples of ascorbic acid or derivatives thereof that suppress the decomposition of the softener include ascorbic acid, sodium ascorbate, calcium ascorbate, trisodium ascorbate 2-phosphate ester, disodium ascorbate 2-sulfate ester, ascorbic acid 2 -Glucosides, ascorbic acid palmitate, ascorbyl dipalmitate, etc. are mentioned. Among these, ascorbic acid, sodium ascorbate, ascorbic acid 2-phosphate trisodium, and ascorbic acid 2-glucoside have a high effect of suppressing the decomposition of the softener, and do not lower the foamability and foam stability of the fixing solution. Therefore, it is particularly preferable.

  The content of the ascorbic acid compound is preferably 0.01% by mass to 10% by mass, and more preferably 0.05% by mass to 5% by mass. When the content is less than 0.01% by mass, decomposition of the softening agent may not be sufficiently suppressed. When the content exceeds 10% by mass, the foamability is rather deteriorated, which is not suitable.

-Anionic surfactant-
The anionic surfactant can realize excellent foamability and foam stability and is used as a foaming agent.
Among the anionic surfactants, fatty acid salts have the highest foam stability and are most suitable as a foaming agent for fixing solutions. On the other hand, the softening agent has a strong defoaming action, and as the concentration of the softening agent increases in the fixing solution, the foaming property and foam stability of the fixing solution deteriorates, so it is difficult to foam and the foam breaks immediately. It becomes impossible to obtain a foam-like fixing solution having a low foam density.

  Therefore, in order to solve the problem of foaming deterioration when the concentration of the softening agent in the fixing solution is increased, various prototypes were made using the type and concentration of the anionic surfactant as factors. In addition, “Ishii Ikuo,“ Engineering of Bubbles ”, first edition, Techno System Co., Ltd., published on March 25, 2005, p. 489 ”, a technique called“ super fat ”, that is, a trial production was conducted focusing on the free fatty acid contained in the solid detergent (soap). Here, to outline the technology called super fat, it is a method of adding a small amount of free fatty acids that are difficult to oxidize to increase the excess fat and oil, leaving a small amount of fat and oil that is not saponified, for example, to enhance the moisturizing action, etc. It is said to be effective. The above-mentioned “Iwao Ishio,“ Engineering of Bubbles ”, first edition, Techno System Co., Ltd., published on March 25, 2005, p. 489 ”describes that when a very small amount of fatty acid is added to a soap aqueous solution, the foaming performance is improved and the foam quality becomes more creamy, which is called super fat soap. ing. Similar to this super fat, an attempt was made to foam by adding a very small amount of fatty acid to a fixing solution having a softening agent, but both foamability and foam stability were poor.

However, as will be described later, by using a fatty acid salt having 12 to 18 carbon atoms as a foaming agent and further containing a fatty acid having 12 to 18 carbon atoms in the fixing solution, the concentration of the softening agent is increased. It is possible to provide a foamy fixing solution in which the foamability of the fixing solution does not deteriorate.
Here, in the fixing solution containing the softening agent, compared with a case where water is simply foamed, the number of carbon atoms of the fatty acid salt is excellent in foaming properties. Specifically, laurate (12 carbon atoms), myristate (14 carbon atoms), palmitate (16 carbon atoms), and stearate (18 carbon atoms) are suitable. Further, pentadecylic acid (carbon number 15), margaric acid (carbon number 17), and the like are also suitable. On the other hand, the action of the fatty acid and the softening agent will be described. The softening agent has an ester group in the chemical structure, and the fatty acid has a carbonyl group in the chemical structure. From this point, the ester group of the softener and the carbonyl group of the fatty acid show an electrical action in the fixing solution system, and this causes a binding action between molecules, and the fixing solution is characterized by foaming properties and Improves foam stability.

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

  The content of the anionic surfactant is preferably 0.1% by mass to 20% by mass, and more preferably 0.5% by mass to 10% by mass. When the content is less than 0.1% by mass, the foamability may be insufficient. When the content is more than 20% by mass, the viscosity of the fixing solution may be increased and the foamability may be reduced. There is.

By containing a fatty acid having the same number of carbon atoms as the foaming agent fatty acid salt in the fixing solution, foamability and foam stability can be maintained even when the concentration of the softening agent is increased. If the concentration of the softening agent is less than 10% by mass, there is no problem in foaming properties even if no fatty acid is contained. However, when the concentration of the softening agent is 10% by mass or more, and particularly when the concentration of the softening agent is 30% by mass or more, the foaming property is hardly generated with the fatty acid salt alone and the foaming property is deteriorated. When the content of such a softening agent is 30% by mass, a foaming property can be maintained by containing a fatty acid having the same carbon number as that of the fatty acid salt.
However, if the content of the fatty acid is too large, the ratio of the fatty acid salt that is a foaming agent is lowered, and the foamability is deteriorated again. Therefore, as can be seen from the specific examples described later, it is better to make the number of moles of the fatty acid salt the same as or larger than the number of moles of the fatty acid. Or when the ratio of a fatty acid and a fatty acid salt is in the range of 5: 5 to 1: 9, the foamability is excellent.

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

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

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

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

  In the foam-like fixing solution, if the foam breaks when the foam-like fixing solution is permeated while being pushed into the fine particle layer such as toner at the coating contact nip portion, the penetration is inhibited. Therefore, a foam excellent in foam stability is required. For this reason, it is preferable to contain a fatty acid alkanolamide (1: 1) type in the fixing solution. Fatty acid alkanolamides include (1: 1) type and (1: 2) type, but (1: 1) type is suitable for foam stability in the present invention.

-Medium-
The medium is not limited to recording paper, and may be any of metal, resin, ceramics and the like. However, the medium is preferably permeable to the fixing solution, and when the medium substrate does not have the liquid permeability, a medium having a liquid permeable layer on the substrate is preferable.
The form of the medium is not limited to a sheet shape, and may be a three-dimensional object having a flat surface and a curved surface. For example, the present invention can also be applied to applications in which transparent resin fine particles are uniformly fixed on a medium such as paper to protect the paper surface (so-called varnish coating).
Among the above-mentioned media, the recording medium is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include paper, cloth, and a plastic film such as an OHP sheet having a liquid permeable layer. .

-Solvent-
As the solvent, water, an aqueous solvent obtained by adding alcohol or the like to water, and the like are preferable.
As water, for example, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used.
When the aqueous solvent is used, it is preferable that the surface tension be 20 mN / m to 30 mN / m by adding a surfactant. Examples of the alcohols include unitary alcohols such as cetanol; ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol, and the like because of the advantage of enhancing the stability of bubbles in the foam-like fixing solution and making it difficult to break bubbles. Polyhydric alcohols such as propylene glycol, tripropylene glycol, 1,3-butylene glycol and glycerin are preferred. Further, containing these unit price or polyhydric alcohols has an effect of preventing curling of a medium such as paper.

  Also preferred is a constitution in which an O / W emulsion or a W / O emulsion is formed by containing an oily component in the fixing solution in order to improve permeability and prevent curling of a medium such as paper. In this case, as a specific dispersant, sorbitan fatty acid esters such as sorbitan monooleate, sorbitan monosterate and sorbitan sesquioleate, and sucrose esters such as sucrose laurate and sucrose stearate are preferable.

  In addition, as a method for dissolving the softening agent or fixing the microemulsion during fixing, 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 Is mentioned. In any case, a strong shear stress is added to the softener in the fixing solution to dissolve or disperse the microemulsion.

-Resin fine particles-
The resin fine particles containing a resin to be fixed are not limited to toner, and any fine particles containing a resin may be used, and resin fine particles containing a conductive member may be used.

  Among the resin fine particles, the toner used in the electrophotographic process has the highest fixing effect in combination with the fixing solution of the present invention.

<Toner>
The toner contains a colorant, a charge control agent, a binder resin, and a release agent, and further contains other components as necessary.

There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polystyrene resin, a styrene-acryl copolymer, a polyester resin etc. are mentioned.
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably, For example, wax components, such as a carbanau wax and polyethylene, etc. are mentioned.
There is no restriction | limiting in particular as said coloring agent, According to the objective, it can select suitably from well-known dyes and pigments.
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary Examples thereof include ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine-based activators, metal salts of salicylic acid, and metal salts of salicylic acid derivatives. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, an external additive, a fluid improvement agent, a cleaning property improvement agent, a magnetic material, metal soap, etc. are mentioned.

  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.

  Also, the foamed fixing solution preferably has sufficient affinity for 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 foamed 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. Actually, 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 approximately 20 mN / m to 30 mN / m. Guessed. Therefore, in order to have affinity for the water-repellent toner (having sufficient wettability), the surface tension of the foamed fixing solution is preferably 20 mN / m to 30 mN / m.

(Fixing method and fixing device)
The fixing method of the present invention includes a foamy fixing solution generation step, a film thickness control step, and a foamy fixing solution application step, and further includes other steps as necessary.
The fixing device of the present invention has a foamy fixing solution generating means, a foamy fixing solution applying means, and a film thickness controlling means, and further has other means as required.

  The fixing method of the present invention can be preferably carried out by the fixing device of the present invention, the foamy fixer generating step can be performed by the foamy fixer generating means, and the film thickness controlling step is performed by the film. Thickness control means can be used, the foamy fixer application step can be performed by the foamy fixer application means, and the other steps can be performed by the other means.

-Foam fixer generating step and foam fixer generating means-
The foamy fixing solution generating step is a step of generating a foamy fixing solution by foaming the fixing solution of the present invention, and is carried out by a foaming fixing solution generating means.

  Here, the film thickness of the foam-like fixing liquid film on the surface of the fixing liquid application unit is controlled as described later according to the thickness of the resin fine particle layer over the entire medium surface for foaming the fixing liquid of the present invention. Yes. However, for example, when the resin fine particles are toner and color images and black and white characters are mixed on the medium, if the entire surface of the medium is applied with a foam-like fixing liquid layer having the same thickness, a thick toner layer such as a color photographic image may cause poor fixing. There may be a partial defect in which an image is lost or a printed material sticks due to a sticky feeling in a black and white character portion. The cause of the problem will be described in detail below.

  In general, in the case of large bubbles of about 0.5 mm to 1 mm, bubbles can be generated relatively easily by simple stirring, etc., and the generation of large bubbles takes less than a few seconds (not longer than 0.1 seconds). can do. Therefore, paying attention to the fact that bubbles that are larger than the desired bubble diameter and that can be easily observed and can be quickly obtained can be obtained quickly, and from about 5 μm to 50 μm quickly from the large bubbles. As a result of diligently studying the method of generating microbubbles, dividing the large foam by applying shear force to the large foam is extremely quick compared to the method of generating microbubbles from the liquid state as described above. Microbubbles of a desired size can be generated.

And as shown in FIG. 4, as a big foam production | generation part in the foam-like fixing liquid production | generation means 30 which separates a big foam and produces | generates the foam of a fine prescription after producing | generating a big foam, as shown in FIG. The liquid fixing liquid 92 of the present invention described above is supplied to the gas / liquid mixing unit 35 using liquid transport means such as the transport pump 33 and the liquid transport pipe 34.
The gas / liquid mixing unit 35 is provided with an air port 36, and a negative pressure is generated in the air port 36 along with the flow of the liquid, and the gas is introduced from the air port 36 into the gas / liquid mixing unit 35. Are mixed and further passed through the microporous sheet 37, whereby large bubbles with uniform bubble diameters can be generated. The pore diameter is preferably 30 μm to 100 μm. The porous member is not limited to the microporous sheet 37 in FIG. 4, and may be a porous member having an open cell structure, and may be a sintered ceramic plate, a nonwoven fabric, or a foamed resin sheet having a pore diameter of 30 μm to 100 μm. As another method for generating large bubbles, the liquid fixer supplied from the above-described transport pump and the air from the air port are stirred with a blade-like stirrer, and large bubbles are generated while bubbles are involved in the liquid. A configuration in which a large bubble is generated by bubbling the liquid fixing solution supplied from the above-described transport pump with an air supply pump or the like is also preferable.

  Next, in order to divide a large bubble into two or more bubbles, a small bubble generation unit 38 in the foam-like fixer generating unit 30 as shown in FIG. 4 is used to apply a shearing force to the large bubble. As a closed double cylinder, the inner cylinder can be rotated, and a large foam-like fixing solution is supplied from a part of the outer cylinder, and the gap between the inner rotating cylinder and the outer cylinder (this is the flow path) And a shearing force is received by the rotating cylinder. Due to this shearing force, the large bubbles are changed into minute bubbles, and a foam-like fixing liquid having a desired minute bubble diameter can be obtained from the outlet of the bubbles provided in the outer cylinder. In addition, a spiral groove may be provided in the inner cylinder to increase the liquid transport capability in the cylinder.

  In this way, liquid fixing is achieved by combining a large bubble generating unit that changes the liquid fixing liquid into a liquid having a large bubble diameter and a fine bubble generating unit that generates a small bubble by applying shear force to the large bubble. It is possible to produce a foam-like fixing solution having a fine bubble diameter of 5 μm to 50 μm in a very short time.

-Film thickness control process and film thickness control means-
The film thickness control step is a step of controlling the film thickness of the foam-like fixing liquid film applied on the contact surface of the foam-like fixing liquid application means to a desired thickness, and is performed by the film thickness control means.
The film thickness control means is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a film thickness control blade and a combination of a blade and a coating roller.

-Foamed fixing solution applying step and foamed fixing solution applying means-
The foamy fixing solution applying step is a step of applying a foamed fixing solution film controlled to a desired thickness to the resin fine particle layer on the medium, and is performed by the foamed fixing solution applying unit.

  Here, FIG. 5A and FIG. 5B are schematic configuration diagrams illustrating an example of a fixing solution applying unit in the fixing device of the present invention. Here, the resin fine particles are toner particles. The fixing device 40 of the present invention shown in FIG. 5A is a coating for applying the desired fine bubble foam fixing solution generated by the above-described foam fixing solution generating means 30 to the resin fine particle layer (toner particle layer). The film thickness of the desired fine foam foam fixing solution on the roller 41 and the application roller surface is controlled according to the thickness of the unfixed toner layer on the recording medium, and the optimum film thickness of the foam fixing solution is controlled. And a pressure roller 43 at a position facing the coating roller 41. As shown in FIG. 5B, on the coating roller 41, a foam-type fixing solution layer 42 is a film thickness control blade 42 of the foam-type fixing solution thickness control means according to the thickness of the unfixed toner layer on the recording medium. A bubble corresponding to the bubble size, bubble viscosity, coating pressure, and unfixed toner layer thickness of the foam-like fixing solution by the film thickness control blade 42 of the foam-like fixing solution film thickness control means. The film thickness of the fixing solution layer is optimized with respect to the permeation time of the unfixed toner layer in the state of the fixing solution. As described above, the desired fine foam foam fixing solution is composed of a large foam generating section that generates large foam and a small foam generating section that separates large foam with a shearing force to generate micro foam. It is generated by the foamed fixing liquid generating means 30 configured to be dripped between the application roller 41 and the film thickness controlling blade 42 of the foamed fixing liquid film thickness controlling means from the liquid supply port.

As the bulk density of the foamy fixing ^{solution, 0.01g / cm 3 ~0.1g / cm} 3 in the range of about preferably. Furthermore, in order to prevent the occurrence of residual liquid feeling on the medium surface when the fixing solution applied is, as the density of the foam ^is preferably ^{0.01g / cm 3 ~0.02g / cm 3} , 0.02g / cm 3 or less Is more preferable. This is because, like the coating roller 41 in FIGS. 5A and 5B, the foam film of the fixing solution on the surface of the contact imparting unit is required to be equal to or greater than the thickness of the resin fine particle layer on the medium (the gap between the fine particle layers is reduced). In general, the thickness of the foam film is preferably 50 μm to 80 μm. On the other hand, in order not to have a feeling of residual liquid (wet feeling) when the fixing solution adheres to the medium surface, the amount of fixing solution attached is preferably 0.1 mg / cm ² or less. Therefore, as the density of the ^foam, preferably in the range of ^{0.0125g / cm 3 ~0.02g / cm 3} , a density of 0.02 g / cm ³ or less of the foam is more preferable.

  Further, the fixing solution is not required to be foamed in the storage container as long as it is foamed when a resin fine particle layer such as toner is applied on a recording medium such as paper. In the storage container, it is a liquid that does not contain bubbles, and it is preferable to provide a means for forming a bubble in the liquid transport path until the liquid is supplied from the container or the resin fine particle layer. This is because the storage container is liquid, and the foamed configuration after the liquid is taken out from the container has a great advantage that the container can be downsized.

  Further, as shown in FIG. 6A, the film thickness control of the foam-like fixing liquid on the application roller is performed using a liquid film thickness control blade 42 provided with a gap as shown in FIGS. 6A and 6B. When the film thickness is reduced, the gap is narrowed. When the film thickness is increased as shown in FIG. 6B, the gap is widened. The gap is controlled using a rotating shaft having a drive at the end of the liquid film thickness control blade 42, and the thickness of the toner layer, the environmental temperature, etc., as well as the bubble size, bubble viscosity and coating pressure of the foam-like fixer. In addition, the optimum film thickness for adjusting the permeation time of the foamy fixing solution in the unfixed toner layer according to the layer thickness of the unfixed toner is controlled.

  Next, as a means for transporting the liquid fixer from the fixer container to the foaming mechanism, a transport pump is used in FIG. Examples of the transfer pump include a gear pump and a bellows pump, and a tube pump is preferable. If there is a vibration mechanism or a rotation mechanism in the fixing liquid, such as a gear pump, the liquid foams in the pump, and the liquid may be compressible, resulting in a decrease in conveying ability. In addition, the above-mentioned mechanical parts or the like may contaminate the fixer or conversely deteriorate the mechanical parts. On the other hand, since the tube pump is a mechanism that pushes out the liquid in the tube while deforming the tube, the only member in contact with the fixing liquid is the tube. By using a member that has liquid resistance to the fixing liquid, No contamination or deterioration of pump system parts. In addition, since the tube is only deformed, the liquid does not foam, and the conveyance capacity can be prevented from being lowered.

  In addition to the film thickness control blades shown in FIGS. 6A and 6B, the thickness of the foam-like fixing solution on the application roller is controlled by a wire bar, and the foam-like fixing solution generates large bubbles as described above. It is generated by a foam-like fixing liquid generating means having a large foam generating part and a fine foam generating part that separates the large foam with a shearing force, and is dropped between the film control wire bar and the application roller from the liquid supply port. By using the wire bar as the film control means, the uniformity of the foam-like fixing liquid film in the axial direction of the coating roller surface is improved as compared with the blade.

  FIG. 7 is a schematic configuration diagram showing a configuration of a fixing device according to an embodiment of the present invention. According to the fixing device 40 of the embodiment shown in FIG. 7, the pressure roller 43 is configured using a sponge material as an elastic layer. Here, it is necessary to take a timing of the nip time so that the coating roller and the resin fine particle layer are peeled after the foamy fixing solution penetrates the resin fine particle layer such as toner and reaches the medium such as paper. For this reason, in order to secure a range of 50 milliseconds to 300 milliseconds as the nip time, a sponge member that can be deformed greatly with a weak pressure is used.

  The nip time is calculated by nip time = nip width / paper conveyance speed. The paper transport speed can be obtained from design data of the paper transport drive mechanism. The nip width is such that a colored paint that does not dry is thinly applied to the entire surface of the application roller, and the recording medium is sandwiched between the application roller 41 and the pressure roller 43 facing the pressure roller (in a state where the roller is not rotated). Can be obtained by measuring the length of the colored portion (usually colored in a rectangular shape) in the paper conveyance direction as the nip width.

  It is necessary to adjust the nip width in accordance with the conveyance speed of the recording medium so that the nip time is equal to or longer than the toner layer penetration time of the foamy fixing solution. In the example shown in FIG. 7, the application roller 41 and the pressure roller are used in accordance with the conveyance speed of the recording medium by using the pressure roller 43 as an elastic layer and an elastic porous body (hereinafter sometimes referred to as a sponge). It becomes easy to change the nip width by changing the distance between the axes 43. An elastic rubber is suitable for the pressure roller 43 instead of the sponge, but the sponge can be deformed with a weaker force than the elastic rubber, and a long nip width is secured without excessively increasing the pressure applied to the application roller 41. can do.

  Note that the fixer contains a softening or swelling agent, and if the fixer should adhere to the pressure roller formed of a sponge material, there is a risk that problems such as softening of the sponge material may occur. The resin material of the sponge material is preferably a material that does not soften or swell against the softening or swelling agent. Further, the pressure roller using a sponge material may be configured to be covered with a flexible film. Even if the sponge material is a material that is softened or deteriorated by a swelling agent, the sponge roller can be prevented from being deteriorated by covering it with a flexible film that does not show softening or swelling by the softening or swelling agent. As the sponge material, for example, a porous body of resin such as polyethylene, polypropylene, and polyamide is suitable. As the flexible film covering the sponge, polyethylene terephthalate, polyethylene, polypropylene, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), or the like is suitable.

  In FIG. 7, when the application roller 41 and the pressure roller 43 using a sponge material are always in contact with each other, the foamy fixing liquid on the application roller 41 is applied to the pressure roller 43 when the recording medium is not conveyed. In order to prevent adhesion and contamination, a paper leading edge detection means (not shown) is provided before the recording medium is transported to the coating roller 41, and only from the leading edge of the recording medium to the rear according to the leading edge detection signal. It is preferable to form the foam-like fixing solution on the application roller 41 at a timing such that the foam-like fixing solution is applied.

  In FIG. 7, the application roller 41 and the pressure roller 43 using sponge material are separated from each other during standby, and the application is performed according to the leading edge detection means of the recording medium only during application by a drive mechanism (not shown). A configuration in which the roller 41 and the pressure roller 43 using a sponge material are in contact with each other is also preferable. Furthermore, it is preferable to detect the trailing edge of the recording medium and to separate the application roller 41 and the pressure roller 43 using a sponge material in accordance with the trailing edge detection signal of the recording medium.

  FIG. 8 is a schematic configuration diagram showing another configuration of the fixing device according to the embodiment of the present invention. The fixing device 40 of the embodiment shown in FIG. 8 uses a pressure belt 44 instead of the pressure roller 43 of FIG. It is generated by a foam-like fixing liquid generating means 30 configured to include a large bubble generating unit that generates large bubbles and a minute bubble generating unit that separates large bubbles with a shearing force to generate minute bubbles, A foam fixing solution having a desired bubble diameter is supplied from the liquid supply port to the supply port of the film thickness control blade 42 of the foam fixing solution film thickness control means using a tube or the like. Then, by adjusting the gap between the film thickness control blade 42 of the foam fixing solution film thickness control means and the coating roller 41, the layer thickness of the foam fixing solution on the coating roller 41 is controlled, The optimum film thickness is controlled. As the pressurizing belt 44, for example, a member such as a seamless nickel belt, a seamless PET file, or the like coated with a releasable fluororesin such as PFA is used.

  Thus, in the configuration using the belt, the nip width can be easily widened. Therefore, the configuration using the belt is not limited to that shown in FIG. 8, and a configuration in which the application roller is a belt and the pressurizing unit is not a belt but a roller is also preferable. In addition, it is possible to easily widen the nip width by using at least one of the application side and the pressure side as a belt, and without applying an excessive force that generates wrinkles on the paper, the nip time can be reduced. If it is the same, it becomes possible to increase the paper conveyance speed, and high-speed fixing is possible.

  Also, the toner fixing device is a pair of smoothing units that supply the fixing liquid according to the present invention to the toner and then pressurize the dissolved or swollen toner with a softening agent that dissolves or swells at least a part of the resin contained in the toner. You may have a roller (hard roller). By pressurizing the dissolved or swollen toner with a pair of smoothing rollers (hard rollers), the surface of the dissolved or swollen toner layer can be smoothed to give the toner gloss. Further, the toner fixability to the recording medium can be improved by pushing the dissolved or swollen toner into the recording medium.

(Image forming method and image forming apparatus)
The image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and other steps appropriately selected as necessary, for example, a static elimination step, a cleaning step. , Including recycling process, control process, etc.
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and further appropriately selected as necessary. It has other means, for example, static elimination means, cleaning means, recycling means, control means and the like.

  The image forming method of the present invention can be preferably carried out by the image forming apparatus of the present invention, the electrostatic latent image forming step can be performed by the electrostatic latent image forming means, and the developing step is the developing The transfer step can be performed by the transfer unit, the fixing step can be performed by the fixing unit, the recharging step can be performed by the recharging unit, and the others. This step can be performed by the other means.

The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier (hereinafter, also referred to as “electrophotographic photoreceptor”, “photoreceptor”, “image carrier”) is particularly limited in terms of material, shape, structure, size, and the like. However, it can be suitably selected from known ones, and the shape thereof is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, polysilane, phthalopolymethine and the like. Organic photoreceptors, and the like. Among these, amorphous silicon or the like is preferable in terms of long life.

  The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by the electrostatic latent image forming unit. be able to. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise. Prepare.

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image with the toner to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using the toner, for example, and can be appropriately selected from known ones. For example, the toner is accommodated and the electrostatic latent image is formed on the electrostatic latent image. Suitable examples include those having at least a developing unit capable of applying the toner in a contact or non-contact manner, and a developing unit including the toner-containing container is more preferable.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner by frictional stirring and a rotatable magnet roller is preferable.

  In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

The fixing step is a step of fixing the transferred image transferred to the recording medium, and is performed by the fixing method of the present invention.
The fixing means is means for fixing the transferred image transferred to the recording medium, and is performed using the fixing device of the present invention.

The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Suitable examples include brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Using the image forming method according to the present invention, a toner image made of resin fine particles is formed on a recording medium. Therefore, according to the image forming apparatus of the embodiment of the present invention, as described above, an image forming method and an image forming apparatus capable of fixing toner onto a recording medium more efficiently are provided. can do.

  Here, FIG. 9A and FIG. 9B are schematic views showing the configuration of the image forming apparatus of the present invention. The image forming apparatus shown in FIGS. 9A and 9B may be a copying machine or a printer. FIG. 9A is a schematic diagram of the entire color electrophotographic tandem type image forming apparatus, and FIG. 9B is a diagram showing a configuration of one image forming unit of the image forming apparatus of FIG. 9A.

  The image forming apparatus 50 shown in FIGS. 9A and 9B includes an intermediate transfer belt 51 as a toner image carrier. The intermediate transfer belt 51 is stretched around three support rollers 52 to 54 and rotates in the direction of arrow A in the figure. On the intermediate transfer belt 51, black, yellow, magenta and cyan image forming units 55 to 58 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 59 is provided at a position facing the support roller 54 of the intermediate transfer belt 51 with the intermediate transfer belt 51 interposed therebetween. The secondary transfer device 59 includes a secondary transfer belt 62 stretched between two support rollers 60 and 61. As the secondary transfer device 59, a transfer roller may be used in addition to the transfer belt. A belt cleaning device 63 is disposed at a position facing the support roller 52 of the intermediate transfer belt 51 with the intermediate transfer belt 51 interposed therebetween. The belt cleaning device 63 is arranged to remove toner remaining on the intermediate transfer belt 51.

  A recording sheet 64 as a recording medium is guided to a secondary transfer unit by a pair of paper feed rollers 65, and the secondary transfer belt 62 is pressed against the intermediate transfer belt 51 when the toner image is transferred to the recording sheet 64. Thus, the toner image is transferred. The recording paper 64 to which the toner image has been transferred is conveyed by the secondary transfer belt 62, and the unfixed toner image transferred to the recording paper 64 is foamed based on image information from an exposure device (not shown). Fixing is performed by the fixing device of the present invention that controls the film thickness of the fixing solution. That is, for the unfixed toner image transferred to the recording paper 64, the film thickness of the foam-like fixing liquid layer is controlled based on image information from an exposure device (not shown) such as 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. Thus, an unfixed toner image is fixed on the recording paper 64.

  Next, the image forming unit will be described. As shown in FIG. 9B, in the image forming units 55 to 58, a charging device 67, a developing device 68, a cleaning device 69, and a charge removal device 70 are disposed around the photosensitive drum 66. Further, a primary transfer device 71 is provided at a position facing the photosensitive drum 66 with the intermediate transfer belt 51 interposed therebetween. The charging device 67 is a contact charging type charging device employing a charging roller. The charging device 67 uniformly charges the surface of the photosensitive drum 66 by bringing a charging roller into contact with the photosensitive drum 66 and applying a voltage to the photosensitive drum 66. As the charging device 67, a non-contact charging type charging device using a non-contact scorotron or the like may be employed. Further, the developing device 68 causes the toner in the developer to adhere to the electrostatic latent image on the photosensitive drum 66 to visualize the electrostatic latent image.

  Here, the toner corresponding to each color consists of resin fine particles colored in the respective colors, and these resin fine particles are dissolved or swollen by the fixing solution in the present invention. The developing device 68 has a stirring unit and a developing unit (not shown), and the developer not 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 71 transfers the toner visualized on the photosensitive drum 66 to the intermediate transfer belt 51. Here, a transfer roller is employed as the primary transfer device 71, and the transfer roller is pressed against the photosensitive drum 66 with the intermediate transfer belt 51 interposed therebetween. As the primary transfer device 71, a conductive brush, a non-contact corona charger, or the like can be employed. The cleaning device 69 removes unnecessary toner on the photosensitive drum 66. As the cleaning device 69, a blade having a tip pressed against the photosensitive drum 66 can be used. Here, the toner recovered by the cleaning device 69 is recovered by the developing device 68 and reused by a recovery screw and a toner recycling device (not shown). Further, the static eliminator 70 is constituted by a lamp, and initializes the surface potential of the photosensitive drum 66 by irradiating light.

  Since the image forming method and the image forming apparatus of the present invention use the fixing solution, the fixing method, and the fixing apparatus of the present invention, the fixing property is good, and a recording medium such as paper is not curled, and a high-quality image is obtained. Can be formed.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Production Example 1)
-Preparation of foaming agent (anionic surfactant) 1-
Fatty acid with a mass ratio of 4: 3: 1 of myristic acid (manufactured by Kanto Chemical Co., Ltd., reagent), palmitic acid (manufactured by Kanto Chemical Co., Ltd., reagent), stearic acid (manufactured by Kanto Chemical Co., Ltd., reagent), Weighed so that the molar ratio of triethanolamine (Kanto Chemical Co., Ltd., reagent), which is a solubilizing agent, was 1: 0.7, stirred in ion-exchanged water at a liquid temperature of 80 ° C. for 30 minutes, The mixture was allowed to cool until it became a fatty acid triethanolamine salt.

(Production Example 2)
-Preparation of foaming agent (anionic surfactant) 2-
In Production Example 1, a fatty acid diethanolamine salt was prepared in the same manner as in Production Example 1 except that the neutralizing agent was diethanolamine (manufactured by Kanto Chemical Co., Ltd., reagent).

(Production Example 3)
-Preparation of foaming agent (anionic surfactant) 3-
In Production Example 1, a fatty acid sodium salt was prepared in the same manner as in Production Example 1 except that the neutralizing agent was sodium hydroxide (manufactured by Kanto Chemical Co., Ltd., reagent).

(Production Example 4)
-Preparation of foaming agent (anionic surfactant) 4-
In Production Example 1, a fatty acid potassium salt was prepared in the same manner as in Production Example 1 except that the neutralizing agent was potassium hydroxide (manufactured by Kanto Chemical Co., Ltd., reagent).

Example 1
-Preparation of Fixer 1-
40% by mass of propylene carbonate (manufactured by Kanto Chemical Co., Ltd., reagent) as a softening agent, 10% by mass of propylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent) as a solubilizer, fatty acid triethanolamine salt (raising agent) as a foaming agent Foaming agent 1) 4.0% by mass, coconut oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass as a foam-increasing agent A certain ascorbic acid (manufactured by Kanto Chemical Co., Ltd., 3.0% by mass) and 42.5% by mass of ion-exchanged water as a diluent are stirred for 10 minutes with an ultrasonic homogenizer, and a fixing solution (stock solution before forming into a foam) 1) was prepared.

(Example 2)
-Preparation of Fixer 2-
40% by mass of propylene carbonate (manufactured by Kanto Chemical Co., Ltd., reagent) as a softening agent, 10% by mass of dipropylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent) as a solubilizer, and fatty acid sodium salt (raising agent) as a foaming agent Foaming agent 3) 4.0% by mass, coconut oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass as a foam-increasing agent A sodium ascorbate (manufactured by Kanto Chemical Co., Ltd., 3.0% by mass) and ion-exchanged water (42.5% by mass) as a diluent are stirred for 10 minutes with an ultrasonic homogenizer, and a fixing solution (before foaming) Stock solution) 2 was prepared.

(Example 3)
-Preparation of Fixer 3-
Softening agent bis (2-methoxyethyl) adipate (manufactured by Tokyo Chemical Industry Co., Ltd., 25% by mass), solubilizing agent dipropylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent) 14% by mass, foaming agent Fatty acid diethanolamine salt (foaming agent 2) 4.0% by mass, palm oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass, An ultrasonic homogenizer containing 5.0% by mass of ascorbic acid 2-phosphate trisodium (reagent) as a softening agent decomposition inhibitor and 51.5% by mass of ion-exchanged water as a diluent. The mixture was stirred for 10 minutes to prepare a fixing solution (stock solution before forming) 3.

Example 4
-Preparation of Fixer 4-
30% by mass of dicarbitol succinate as a softening agent (manufactured by Higher Alcohol Industry Co., Ltd., reagent), 4.0% by mass of fatty acid diethanolamine salt (foaming agent 2) as a foaming agent, and palm oil fatty acid diethanolamine as a foaming agent Dos (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5 mass%, ascorbic acid 2-glucoside (reagent) 5.0 6% by mass of ion exchange water as a diluent and 60.5% by mass of a diluent were stirred for 10 minutes with an ultrasonic homogenizer to prepare a fixing solution (stock solution before forming) 4.

(Example 5)
-Preparation of Fixer 5-
30% by mass of dicarbitol succinate as a softener (manufactured by Higher Alcohol Industry Co., Ltd., reagent), 4.0% by mass of a fatty acid potassium salt (foaming agent 4) as a foaming agent, and coconut oil fatty acid diethanolamine as a foaming agent 4. (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5 mass%, ascorbyl palmitate ester (reagent) manufactured by Wako Pure Chemical Industries, Ltd., which is a softening agent decomposition inhibitor 0% by mass and 60.5% by mass of ion-exchanged water as a diluent were stirred with an ultrasonic homogenizer for 10 minutes to prepare a fixing solution (stock solution before forming) 5.

(Example 6)
-Preparation of Fixer 6-
30% by mass of triethylene glycol diacetate (reagent), a softening agent, 4.0% by mass of fatty acid diethanolamine salt (foaming agent 2) as a foaming agent, and coconut oil as a foaming agent Fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass, softening agent decomposition inhibitor ascorbic acid (Kanto Chemical Co., Ltd., reagent) 3.0% by mass Then, 62.5% by mass of ion-exchanged water as a diluent was stirred with an ultrasonic homogenizer for 10 minutes to prepare a fixing solution (stock solution before forming) 6.

(Example 7)
-Preparation of Fixer 7-
30% by mass of triethylene glycol diacetate (reagent), a softening agent, 4.0% by mass of sodium n-dodecyl sulfate (reagent, manufactured by Kanto Chemical Co., Ltd.), a foaming agent, foam increase Coconut oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass, ascorbic acid 2-glucoside as a softener degradation inhibitor (Hayashibara Biochemical Research Institute) Manufactured, reagent) 5.0% by mass and 60.5% by mass of ion-exchanged water as a diluent were stirred with an ultrasonic homogenizer for 10 minutes to prepare a fixing solution (stock solution before forming) 7.

(Comparative Example 1)
-Preparation of Fixer 8-
40% by mass of propylene carbonate (manufactured by Kanto Chemical Co., Ltd., reagent) as a softening agent, 10% by mass of propylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent) as a solubilizer, fatty acid triethanolamine salt as a foaming agent ( Foaming agent 1) 4.0% by mass, coconut oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass as a foaming agent, ion exchange as a diluent 45.5% by mass of water was stirred with an ultrasonic homogenizer for 10 minutes to prepare a fixing solution (stock solution before forming) 8.

(Comparative Example 2)
-Preparation of Fixer 9-
Softening agent bis (2-methoxyethyl) adipate (manufactured by Tokyo Chemical Industry Co., Ltd., 25% by mass), solubilizing agent dipropylene glycol (manufactured by Kanto Chemical Co., Ltd., reagent) 14% by mass, foaming agent Fatty acid diethanolamine salt (foaming agent 2) 4.0% by mass, palm oil fatty acid diethanolamide (1: 1) type (Matsumoto Yushi Seiyaku Co., Ltd., Marpon MM) 0.5% by mass, A fixer (stock solution before forming) 9 was prepared by stirring 56.5% by mass of ion-exchanged water as a diluent with an ultrasonic homogenizer for 10 minutes.

  Next, with respect to the obtained fixing solutions 1 to 9, the remaining ratio of the softener was measured as follows. The results are shown in Table 1.

<Measurement of residual ratio of softener>
In order to measure the residual ratio of the softener in the fixing solution, each fixing solution was put in a polypropylene container with a lid and stored at 40 ° C. for one month, and gas chromatography measurement was performed on the fixing solution before and after storage. Regarding gas chromatography measurement conditions, the apparatus was HEWLETT PACKARD 5890 SERIESII, the column used was HEWLETT PACKARD HP-1 (30 m × 0.25 mm × 0.25 μm), the column temperature was 50 ° C. to 250 ° C., the injection temperature was 200 ° C., The detector temperature was 200 ° C. and the sample volume was 1 μL. In addition, the gas chromatography measurement detects only what is gasified in the apparatus.
From the peak area of the softener before and after storage, the remaining ratio of the softener was determined by the following formula.
Residual rate of softener (%) = (peak area of softener after storage / peak area of softener before storage) × 100

From the results of Table 1, the fixing liquid containing the ascorbic acid compound (Examples 1 to 7) had a higher softener remaining rate than the fixing liquid not containing the ascorbic acid compound (Comparative Examples 1 and 2). Therefore, it was shown that the ascorbic acid compound suppresses the decomposition of the softener.

(Examples 8 to 14 and Comparative Examples 3 to 4)
<Preparation of foamy fixing solution>
-Large bubble generation part-
A large-foamed fixing solution was prepared from the liquid fixing solution based on the foamy fixing solution generating means shown in FIG. The large foam generation part in FIG. 4 is a storage container for a liquid fixing solution: a bottle made of polyethylene terephthalate (PET) resin, a liquid transport pump: a tube pump (tube inner diameter 2 mm, tube material: silicone rubber), a transport flow path: an inner diameter 2 mm. Silicone rubber tube, microporous sheet for producing large bubbles: # 400 stainless steel mesh sheet (opening: about 40 μm).

-Microbubble generator-
Based on the foamy fixer generating means shown in FIG. 4, a fine foamy fixer was prepared from the fixer in a large foam state. The inner cylinder of the double cylinder in FIG. 4 is fixed to a rotation shaft and is rotated by a rotation drive motor (not shown). The material of the double cylinder was PET resin. Outer cylinder inner diameter: 10 mm, length 120 mm, inner cylinder outer shape: 8 mm, length 100 mm. The rotation speed was 300 rpm. The rotation time was 10 seconds.

<Evaluation of foamability>
In order to evaluate the foaming property of the fixing solution, a fine foamy fixing solution was prepared for the fixing solution before and after the storage test, and the bubble density was measured.
Here, it is an indispensable condition that the foam film of the fixing solution on the surface of the contact applying means as in the case of the application roller is not less than the thickness of the fine particle layer on the medium (in order to fill the gap between the fine particle layers with the foam fixing solution). In general, the thickness of the foam film is desirably 50 μm to 80 μm. On the other hand, in order not to have a residual liquid feeling (wet feeling) due to the fixing liquid adhering to the medium surface, the fixing liquid adhesion amount is preferably 0.1 mg / cm ² or less. From this, the density of the foam is preferably 0.0200 g / cm ³ or less, more preferably 0.0125 g / cm ^{3 to} 0.0200 g / cm ³ .
Therefore, the foamability was evaluated according to the following criteria from the value of the foam density of the fine foam-like fixing solution. The results are shown in Table 2. The foam density was calculated by filling a container with a known volume with foam without any gap and measuring the weight.
〔Evaluation criteria〕
0.0125 to 0.0200 g / cm ³ : ○ (good foaming property)
0.0201-0.0300 g / cm < ³ > :( triangle | delta)
0.0301 to 0.0500 g / cm ³ : ×
0.0501 g / cm ³ or more: xx (poor foaming property)

<Evaluation of foam stability>
The above minute bubbles were allowed to stand for 1 minute, the state of the bubbles was visually observed, and the foam stability was evaluated according to the following criteria. The results are shown in Table 2.
〔Evaluation criteria〕
If the foam state does not change after standing for 1 minute: ○ (Foam stability is good)
If the foam disappears after standing for 1 minute: x (poor foam stability)

From the results shown in Table 2, the fixers containing the ascorbic acid compound (Examples 8 to 14) showed good foaming properties and foam stability immediately after preparation. In addition, foamability and foam stability remained good even after storage at 40 ° C. for 1 month. On the other hand, the fixers containing no ascorbic acid compound (Comparative Examples 3 and 4) were stored at 40 ° C. for 1 month, and the foamability and foam stability were reduced. Therefore, it was shown that the ascorbic acid compound does not lower the foamability and foam stability of the fixing solution over a long period of time.

(Examples 15 to 21 and Comparative Examples 5 to 6)
<Application of foamy fixing solution>
-Fixer application means-
Based on FIGS. 5A and 5B, a foamy fixing solution was prepared and supplied to the blade. The gap between the blade and the application roller was 40 μm.
Pressure roller: Sponge roller with aluminum alloy roller (diameter 10 mm) as the core and polyurethane foam material (product name “Color Foam EMO” manufactured by INOAC) with an outer diameter of 50 mm, coating roller: PFA resin is baked Painted SUS roller (diameter 30 mm), linear speed 300 mm / s, film thickness control blade: 1 mm thick parallel glass bonded to an aluminum alloy support plate, with the glass surface facing the application roller, the range of 10 μm to 100 μm In this configuration, the gap between the coating roller and the glass surface can be controlled, and the paper conveyance speed is 300 mm / s.

<Evaluation of fixability>
In order to evaluate the fixability, the fine foamy fixing solution was applied onto the paper on which the unfixed toner was formed by the method described above. In other words, an unfixed toner color image was formed on PPC paper (Ricoh Co., Ltd., T-6200) using an electrophotographic printer (Ricoh Co., Ltd., imagio MPC2500). . At this time, the thickness of the toner layer was 30 μm to 40 μm, and the thickness of the foamy fixing solution on the coating roller was about 70 μm.
Each fixer is put in a polypropylene container with a lid and stored at 40 ° C. for 1 month. For the fixer before and after storage, the amount of foam fixer applied is calculated from the weight of the paper before and after application, and the fixability is as follows. Evaluated by criteria. The results are shown in Table 3.
〔Evaluation criteria〕
When toner is fixed on paper and paper is not curled: ○ (Good fixability)
If the toner is fixed on the paper but the paper is curled: △
When toner is not fixed on paper and paper is not curled: ×
When the toner is not fixed on the paper and the paper is curled: XX (Fixing failure)

From the results shown in Table 3, the fixing solutions containing the ascorbic acid compound (Examples 15 to 21) had a stable coating amount and good fixability even after being stored at 40 ° C. for 1 month. Was not curled. On the other hand, in the fixing solution containing no ascorbic acid compound (Comparative Examples 5 and 6), the toner was not fixed on the paper. This is considered to be because the softening agent in the fixing solution was decomposed and the fixing performance was lowered.

  The fixing solution, the fixing method, and the image forming method and image forming apparatus using the fixing device of the present invention are, for example, a laser printer, a direct digital plate making machine, a full-color copying machine using a direct or indirect electrophotographic multicolor image developing system. It can be used widely for full-color laser printers and full-color plain paper fax machines.

FIG. 1A is a schematic cross-sectional view showing a state of an offset generated in a conventional fixing device. FIG. 1B is a schematic cross-sectional view illustrating an offset state generated in a conventional fixing device. FIG. 2 is a schematic cross-sectional view showing how the resin fine particles are fixed after the fixing solution is applied according to the principle of the present invention. FIG. 3 is a schematic cross-sectional view showing the configuration of the foamy fixing solution. FIG. 4 is a schematic diagram showing the configuration of the foamy fixing solution generating means in the fixing device of the present invention. FIG. 5A is a schematic configuration diagram illustrating an example of a fixing solution applying unit in the fixing device of the present invention. FIG. 5B is a schematic configuration diagram illustrating an example of a fixing solution applying unit in the fixing device of the present invention. FIG. 6A is a schematic view showing a state of film thickness control on a coating roller of a foam-like fixing liquid using a liquid film thickness control blade. FIG. 6B is a schematic diagram showing a state of film thickness control on the application roller of the foam-like fixing liquid using a liquid film thickness control blade. FIG. 7 is a schematic configuration diagram showing a configuration of a fixing device according to an embodiment of the present invention. FIG. 8 is a schematic configuration diagram showing another configuration of the fixing device according to the embodiment of the present invention. FIG. 9A is a schematic diagram showing an example of the configuration of the image forming apparatus of the present invention. FIG. 9B is a schematic diagram illustrating an example of the configuration of the image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Application roller 12 Recording medium 13 Resin fine particle layer 14 Foamed fixing liquid 30 Foamed fixing liquid production | generation means 40 Fixing apparatus 50 Image forming apparatus

Claims (11)

  A fixing solution comprising a softening agent that softens resin fine particles containing the resin by dissolving or swelling at least a part of the resin, an anionic surfactant, an ascorbic acid compound, and a solvent. .   The fixing solution according to claim 1, wherein the softening agent is an ester compound.   The fixing solution according to claim 2, wherein the ester compound is an aliphatic ester.   The fixing solution according to claim 2, wherein the ester compound is a carbonate ester.   The fixing solution according to claim 1, wherein the anionic surfactant is a fatty acid salt having 12 to 18 carbon atoms.   The fixing solution according to claim 5, wherein the fatty acid salt is any one of a fatty acid sodium salt, a fatty acid potassium salt, and a fatty acid amine salt.   The fixing solution according to claim 1, wherein the ascorbic acid compound is any one selected from ascorbic acid, sodium ascorbate, trisodium ascorbate 2-phosphate, and 2-glucoside ascorbate. A foam-like fixing solution generating step for producing a foam-like fixing solution by foaming the fixing solution according to claim 1;
A film thickness control step for controlling the film thickness of the foam-like fixer film applied on the contact surface of the foam-like fixer application means to a desired thickness;
A fixing method comprising a step of applying a foam-like fixing liquid film to a resin fine particle layer on a medium with a foam-like fixing liquid film controlled to have a desired thickness. A foam-like fixing solution generating means for forming a foam-like fixing solution by foaming the fixing solution according to claim 1;
A foam-like fixing solution applying means for applying the foam-like fixing solution to a resin fine particle layer on a medium, and having a curved surface portion at least in part;
And a film thickness control means for controlling the film thickness of the foam-like fixing liquid film applied on the contact surface of the foam-like fixing liquid application means. An electrostatic latent image forming step for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image can be developed using a developer containing resin fine particles containing a resin and a colorant. An image forming method comprising: a development step for forming a visual image; a transfer step for transferring the visible image to a recording medium; and a fixing step for fixing the transfer image transferred to the recording medium.
The image forming method according to claim 8, wherein the fixing step is performed by the fixing method according to claim 8. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image includes resin fine particles containing a resin and a colorant. A developing unit that develops a visible image by developing with a developer; a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transferred image transferred to the recording medium. An image forming apparatus,
An image forming apparatus using the fixing device according to claim 9 as the fixing unit.