JP2016016556A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet type image forming apparatus capable of providing an image having high picture quality by using a process liquid which suppresses bleeding around printed parts of characters and narrow lines, bleeding at color boundaries, and paper deformation due to moisture content in an aqueous ink, and is easy to be coated uniformly.SOLUTION: In an image forming apparatus 100 comprising heads 61Y, 61M, 61C, and 61BK which discharge aqueous recording liquids onto a recording medium 37, and a process liquid imparting means which imparts the process liquid onto the recording medium 37. The process liquid is formed as a W/O emulsion by means of a first surfactant. In the process liquid, a dispersion phase at least contains a hydrophilic polymer, and a continuous phase at least contains a nonpolar solvent which is incompatible with the dispersion phase, and a polar solvent which is incompatible with the dispersion phase.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ink jet image forming apparatus that forms an image by ejecting a recording liquid such as ink from a head.

  Ink jet recording ejects ink from a fine nozzle of several tens of μm, and therefore, a dye having high solubility has been used as a colorant for the ink because of problems such as ink clogging. Dye inks have excellent color developability, and can obtain image quality comparable to silver salt photographs in photographic prints, but on the other hand, they have inferior image storage stability such as water resistance, light resistance and gas resistance. Yes. In order to compensate for this problem, the use of pigments as an ink colorant has been promoted, and it is now installed in printers in the personal market and office market, from industrial large format printers.

  When printing images on plain paper using the inkjet recording method, bleeding around the printed part of characters and fine lines (feathering), bleeding at color boundaries such as two-color overlapping parts (bleeding), water-based ink moisture Paper deformation (curl, cockling) is likely to occur. Therefore, in order to suppress such bleeding and paper deformation, a technique using a liquid or fine particles has been proposed (see, for example, Patent Documents 1 to 3).

For example, there has been proposed a technique for forming an image by using a treatment liquid containing a polyvalent metal salt that reacts with a colorant in an ink to cause an aggregating action and ejects the ink to a portion to which the treatment liquid adheres (for example, , See Patent Document 1).
Further, a technique has been proposed in which a processing liquid containing a cationic polymer compound and a surfactant and / or a wettability promoter is used to form an image by ejecting ink to a portion where the processing liquid is adhered (for example, , See Patent Document 2).
A technology in which a water-absorbing resin fine particle layer such as polyacrylic acid is provided on the surface of the intermediate transfer member to absorb moisture in the ink applied to the intermediate transfer member, and then transferred to the recording medium together with the water-absorbing resin fine particles. Has been proposed (see, for example, Patent Document 3).

However, although the technique using the treatment liquid containing the above-described polyvalent metal salt is effective for suppressing bleeding, the treatment liquid must be applied in a relatively large amount, and a large amount of liquid containing moisture is covered. Since it is applied to the recording medium, there is a problem that it is not effective for paper deformation.
Similarly, a technique using a treatment liquid containing a cationic polymer compound and the like is effective for suppressing bleeding, but has a problem that it is not effective for paper deformation caused by moisture.
Further, the technique using the water-absorbing resin fine particles has a problem that, when trying to obtain an effect for suppressing bleeding and paper deformation, the water-absorbing resin fine particles become agglomerated due to moisture absorption during storage, making uniform application difficult.

  The present inventors have conducted research in view of the above-described problems in the prior art, and previously described "a head for discharging an aqueous recording liquid to a recording medium, water containing a water-soluble polymer, and water incompatible with this water. The low-polarity solvent is applied to the recording medium by a first surfactant and emulsified as a W / O emulsion in which the water becomes a dispersed phase and the low-polarity solvent becomes a continuous phase. An image forming apparatus having an applying unit that performs the above-mentioned "(for example, see Patent Document 4).

According to this, even when plain paper is used as the recording medium in the ink jet recording method, bleeding around the printed portion of characters and fine lines (feathering), bleeding at the color boundary such as a two-color overlapping portion (bleeding), water-based Paper deformation (curling and cockling) due to ink moisture is suppressed, uniform application is easy, and a high-quality image can be obtained using a processing solution that is relatively easy to store.
An object of the present invention is to improve the present invention to better suppress bleeding, curling and cockling, and to easily apply evenly and use a processing solution that is relatively easy to store, and can provide high-quality images. Is to provide an image forming apparatus capable of obtaining the above.

  In order to solve the above problems, the present invention provides an image forming apparatus including a head that discharges an aqueous recording liquid onto a recording medium, and a processing liquid applying unit that applies the processing liquid to the recording medium. 1 surfactant to form a W / O emulsion, the dispersed phase contains at least a hydrophilic polymer, and the continuous phase is at least a non-polar solvent incompatible with the dispersed phase and incompatible with the dispersed phase. And a polar solvent.

  The present invention suppresses feathering, bleeding, curling, and cockling even when plain paper is used as the recording medium, and is easy to apply uniformly and relatively easy to store. An image forming apparatus capable of obtaining an image can be provided.

1 is a schematic front view illustrating a configuration in an embodiment of an image forming apparatus according to the present invention. (A) is a schematic diagram of a W / O emulsion, (b) is a schematic diagram of the state in which both the water phase and the oil phase are continuous phases. (C) is a schematic diagram of an O / W emulsion. It is a schematic front view which shows the structure in other embodiment of the image forming apparatus which concerns on this invention.

An image forming apparatus according to the present invention includes a head that discharges an aqueous recording liquid onto a recording medium, and a processing liquid application unit that applies a processing liquid to the recording medium, and the processing liquid is a first surfactant. The dispersed phase contains at least a hydrophilic polymer, and the continuous phase contains at least an incompatible nonpolar solvent in the dispersed phase and an incompatible polar solvent in the dispersed phase. It is characterized by this.
The present invention will be described in further detail.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are applied, but the scope of the present invention is limited to the following description. Unless otherwise described, the present invention is not limited to these embodiments.

FIG. 1 shows an outline of an example of an image forming apparatus to which the present invention is applied.
The image forming apparatus 100 is a printer as an inkjet printer, and can perform full-color image formation. The image forming apparatus 100 performs an image forming process based on an image signal corresponding to image information received from the outside.
The image forming apparatus 100 can form an image on a sheet-like recording medium using not only plain paper generally used for copying, but also OHP sheets, cardboard, cardboard, cardboard, and envelopes. It is. The image forming apparatus 100 is a single-sided image forming apparatus capable of forming an image on one side of a transfer sheet S as a recording sheet as a recording medium, but may be a double-sided image forming apparatus capable of forming an image on both sides of the transfer sheet S. Good.

  The image forming apparatus 100 can form an image as an image corresponding to each color separated into yellow, magenta, cyan, and black, and can serve as a recording liquid ejector that ejects a recording liquid as ink of that color. The recording heads 61Y, 61M, 61C, and 61BK are the ink heads. The image forming apparatus 100 also includes a head 61T as a recording head that is an ink head as a recording liquid discharger that discharges recording liquid as colorless and transparent ink.

  Heads 61Y, 61M, 61C, 61BK and 61T as recording head means are outer peripheral surfaces of an intermediate transfer body 37 as an intermediate transfer roller which is an intermediate transfer drum disposed at a substantially central portion of the main body 99 of the image forming apparatus 100. It is arrange | positioned in the position facing. The heads 61Y, 61M, 61C, 61BK, and 61T are arranged in this order from the upstream side in the A1 direction, which is the moving direction of the intermediate transfer member 37 and is the clockwise direction in FIG. In the drawing, Y, M, C, BK, and T added after the numerals of the reference numerals indicate yellow, magenta, cyan, black, and colorless and transparent members.

  The heads 61Y, 61M, 61C, and 61BK are ink discharge devices that are recording liquid discharge devices as image forming units for forming yellow (Y), magenta (M), cyan (C), and black (BK) images, respectively. The devices 60Y, 60M, 60C, and 60BK are provided. The head 61T is provided in an ink discharge device 60T, which is a recording liquid discharge device as an image forming unit for forming a colorless and transparent (T) image. Each of the heads 61Y, 61M, 61C, 61BK, and 61T is a line provided in the ink ejection devices 60Y, 60M, 60C, 60BK, and 60T in a form in which a plurality of the heads 61Y, 61M, 61C, 61BK, and 61T are arranged in a direction perpendicular to the paper surface of FIG. Head.

  The intermediate transfer body 37 is rotated in the A1 direction and is recorded in yellow, magenta, cyan, and black from the heads 61Y, 61M, 61C, and 61BK in an area facing the heads 61Y, 61M, 61C, and 61BK. The liquid is discharged and applied in a manner in which the liquids are sequentially superimposed. The intermediate transfer member 37 is an area facing the head 61T while being rotated in the A1 direction. In the area where the colorless and transparent recording liquid is applied from the head 61T to the yellow, magenta, cyan, and black recording liquids. It is discharged and applied to a second region different from a certain first region. Thereby, the intermediate transfer body 37 functions as a recording medium on which an image as a primary image is formed on a primary image forming surface as a surface thereof. As described above, the image forming apparatus 100 has a tandem structure in which the heads 61Y, 61M, 61C, and 61BK are opposed to the intermediate transfer member 37 and are arranged in parallel in the A1 direction.

  The recording liquid is discharged or applied to the intermediate transfer member 37 by the heads 61Y, 61M, 61C, 61BK, and 61T at different timings from the upstream side toward the downstream side in the A1 direction. As a result, image areas of yellow, magenta, cyan, and black are overlapped at the same position on the intermediate transfer member 37 to form an image in the first area, and a colorless and transparent image area is changed to the second area. It is formed.

  The first area is an image portion constituting an image that the user desires to form among the image formable areas where the recording liquid can be applied by the heads 61Y, 61M, 61C, 61BK, 61T. The second area is a non-image portion that constitutes an inverted image of an image that the user desires to form in the image forming area.

  The composition of each recording liquid ejected by the heads 61Y, 61M, 61C, 61BK, 61T will be described later. Note that the recording liquid ejected by the head 61T is not colorless and transparent because it does not interfere with the image formed by the recording liquid ejected by the heads 61Y, 61M, 61C, 61BK. May be attached.

As shown in FIG. 1, the image forming apparatus 100 includes ink ejection devices 60Y, 60M, 60C, 60BK, and 60T each having heads 61Y, 61M, 61C, 61BK, and 61T.
The image forming apparatus 100 also includes a transport unit 10 as a paper transport unit that includes the intermediate transfer body 37 and transports the transfer paper S as the intermediate transfer body 37 rotates in the A1 direction. The image forming apparatus 100 also includes a paper feeding unit 20 that can stack a large number of transfer papers S and feeds only the uppermost transfer paper S among the stacked transfer papers S to the transport unit 10. .
The image forming apparatus 100 also includes a paper discharge tray 25 on which a large number of image-formed, in other words printed, transfer sheets S conveyed by the conveyance unit 10 can be stacked.

The image forming apparatus 100 is also a cleaning unit that is disposed on the left side of the intermediate transfer body 37 in FIG. 1 so as to face the intermediate transfer body 37 as a cleaning unit for cleaning the intermediate transfer body 37. A device 40 is included.
The image forming apparatus 100 is also disposed above the intermediate transfer body 37 in the figure so as to face the intermediate transfer body 37, and a processing liquid having a predetermined composition and a predetermined state, which will be described later, is used as an intermediate recording medium. An application device 73 is provided as application means for applying to the transfer body 37.

The image forming apparatus 100 also includes a carriage 62 as a head support that integrally supports the heads 61Y, 61M, 61C, 61BK, and 61T.
The image forming apparatus 100 also includes a control unit 98 as a control unit that includes a CPU, a memory, and the like (not shown) that control the overall operation of the image forming apparatus 100.
The image forming apparatus 100 also includes an environment detection sensor 35 that detects an environmental temperature and an environmental humidity at which image formation is performed in the image forming apparatus 100 and inputs the detected environmental temperature and environmental humidity to the control unit 98. In addition, an application amount adjusting device 76 that controls the application amount of the treatment liquid according to a signal based on the environmental temperature and the environmental humidity from the control unit 98 is provided.
The image forming apparatus 100 also includes an image area detection sensor (not shown) that detects an image area where image formation is performed in the image forming apparatus 100 and inputs the detected image area to the control unit 98. Further, it has a processing liquid region control mechanism (not shown) that controls the processing liquid application region in accordance with a signal based on the image region from the control unit 98.

  What are the control substrates (not shown) of the heads 61Y, 61M, 61C, 61BK, 61T provided in the recording liquid ejection devices 60Y, 60M, 60C, 60BK, 60T, the transport unit 10, the cleaning device 40, and the control unit 98? Constitutes the printing unit.

  In addition to the intermediate transfer member 37, the transport unit 10 is disposed on the intermediate transfer member 37 when the transfer sheet S passes through the transfer portion 31 between the intermediate transfer member 37 and the intermediate transfer member 37. A transfer device 36 for transferring the primary image formed by the recording liquid onto the transfer paper S is provided.

The transport unit 10 also includes a transport roller 32 that transports the transfer paper S fed from the paper supply unit 20 toward the transfer unit 31.
The transport unit also includes a registration roller 34 that temporarily stops the transfer sheet S transported by the transport roller 32 and feeds the transfer sheet S temporarily stopped at a predetermined timing described later to the transfer unit 31. doing.

The transport unit 10 also has a guide plate 39 that guides the transfer paper S fed from the paper supply unit 20 to the transfer unit 31 and guides the transfer paper S that has passed through the transfer unit 31 to the paper discharge table 25. doing.
The transport unit 10 also has a motor or the like as driving means (not shown) that rotationally drives the intermediate transfer member 37 in the A1 direction.

  The registration roller 34 feeds the transfer sheet S to the transfer unit 31 at a timing when the image formed on the intermediate transfer member 37 reaches the transfer unit 31 as the intermediate transfer member 37 rotates in the A1 direction.

The transfer device 36 sandwiches the transfer sheet S with the intermediate transfer member 37, and transfers the image on the intermediate transfer member 37 to the transfer sheet S while being driven by the intermediate transfer member 37 while being rotated. A transfer roller 38 serving as a transfer member.
The transfer device 36 also has a contact / separation device 77 as contact / separation means for bringing the transfer roller 38 close to or away from the intermediate transfer member 37.
The transfer device 36 also has a cleaning device 78 that is a transfer cleaning device as a cleaning means for cleaning the transfer roller 38.

  The transfer roller 38 is preferably provided with a water-repellent member having a low surface energy on the surface from the viewpoint of preventing contamination by the recording liquid and the processing liquid. Therefore, the transfer roller 38 has a fluororesin such as tetrafluoroethylene resin, tetrafluoroethylene / perfluoroalkoxyethylene copolymer, fluorosilicone rubber, phenylsilicone rubber, fluororubber, chloroprene rubber, nitrile rubber on the surface. And rubber materials such as nitrile butadiene rubber and isoprene rubber. Further, a surface member such as resin, metal, ceramic, or rubber may be further subjected to fluorine treatment on the outermost surface.

  Regarding the physical properties of the transfer roller 38 as a surface member, the water receding contact angle is 60 ° or more, preferably 80 ° or more, and the hardness is 60 or more, preferably 80 or more, according to JIS-A. The thickness of the surface layer is preferably about 0.1 to 1 mm, and preferably 0.2 to 0.6 mm.

  The contact / separation device 77 is displaced so that the transfer roller 38 approaches the intermediate transfer body 37 when the leading edge of the transfer sheet S fed toward the transfer unit 31 by the registration roller 34 enters the transfer unit 31. Then, the transfer sheet S is sandwiched between the intermediate transfer member 37 and the transfer roller 38. The transfer roller 38 is pressed toward the intermediate transfer body 37 in a state where the transfer sheet S is held between the intermediate transfer body 37 and the transfer paper S is pressed against the intermediate transfer body 37. It functions as a pressure roller as a member.

  The contact / separation device 77 is also sandwiched between the intermediate transfer member 37 and the transfer roller 38 and is transferred at the timing when the trailing edge of the transfer sheet S conveyed through the transfer unit 31 by the rotation of the intermediate transfer member 37 passes through the transfer unit 31. The transfer roller 38 is displaced so as to be separated from the intermediate transfer member 37.

  The driving of the transfer roller 38 by the contact / separation device 77 at such timing is controlled by the control unit 98. In this respect, the control unit 98 functions as a transfer control unit. The control by the control unit 98 functioning as a transfer control unit prevents the transfer roller 38 from directly contacting the intermediate transfer body 37 and prevents the treatment liquid and recording liquid on the surface of the intermediate transfer body 37 from adhering. ing.

  The cleaning device 78 cleans the transfer roller 38 by removing, from the transfer roller 38, paper dust adhering to the transfer paper S and the processing liquid and recording liquid transferred from the intermediate transfer body 37 for some reason. Although the cleaning device 78 is fixed at a fixed position, it may be displaced together with the transfer roller 38 by the contact / separation device 77.

  The cleaning device 78 is used when paper dust, the processing liquid on the intermediate transfer body 37, and the adhesion of the recording liquid to the transfer roller 38 do not affect the image formation, the stain or curl of the transfer paper S, or the influence is ignored. If it is possible, it can be omitted. The contact / separation device 77 is used when the treatment liquid or the recording liquid adheres to the transfer roller 38 does not affect the image formation, the stain or curl of the transfer paper S, or when such influence is negligible. It can be omitted. However, if the contact / separation device 77 is omitted, the amount of treatment liquid and recording liquid on the intermediate transfer body 37 adhering to the transfer roller 38 may become large. In this case, the cleaning device 78 may be provided. desirable.

As described above, the transfer device 36 is provided in the image forming apparatus 100 and the transport unit 10 as a transfer unit that is a transfer recording unit that transfers and records the image on the intermediate transfer body 37 onto the transfer sheet S. The transfer device 36 may include a drive source such as a motor that drives the transfer roller 38 to rotate in the same direction as the A1 direction at a position facing the intermediate transfer body 37. The control unit 98 that functions as a transfer control unit controls a configuration in which driving is controlled in the transfer device 36, such as the drive source, in addition to the contact / separation device 77.
As is apparent from the above description, the image forming apparatus 100 is an indirect image forming apparatus that indirectly performs image formation on the transfer sheet S using the intermediate transfer body 37.

The intermediate transfer member 37 includes a support 37a made of aluminum and a surface layer 37b made of silicone rubber formed on the support 37a.
The material of the support 37a is not limited to aluminum, and may have mechanical strength, and is formed of a metal, an alloy, or the like. Specifically, the support 37a is not limited to aluminum, and may be formed of nickel, a nickel alloy, a thermosetting resin, ceramic, or the like.

The material of the surface layer 37b is not limited to silicone rubber, and an elastic material having low surface energy and high followability to the transfer paper S is preferable in that it is a material having high releasability of the recording liquid. The elasticity of the surface layer 37b is a function required at the time of transfer. When the surface layer 37b is deformed along the fibers of the transfer paper S, the contact area is improved and a high transfer rate is achieved. In order to transfer at a low pressure, a material that is somewhat soft must be selected as the material of the surface layer 37b. Specifically, the surface layer 37b is not limited to being made of silicone rubber, and may be formed of fluorosilicone rubber, phenyl silicone rubber, fluorine rubber, chloroprene rubber, nitrile rubber, nitrile butadiene rubber, isoprene rubber, or the like. Further, the thickness of the surface layer 37b is preferably about 0.1 to 1 mm, and preferably 0.2 to 0.6 mm.
Regarding the physical properties of the surface layer 37b, the water receding contact angle of water is 60 ° or more, preferably 80 ° or more, and the hardness is 60 or less, preferably 40 or less in JIS-A. The thickness of the surface layer is preferably about 0.1 to 1 mm, and preferably 0.2 to 0.6 mm.

The paper feed unit 20 feeds only the uppermost transfer paper S among the paper feed tray 21 on which a large number of transfer papers S can be stacked and the transfer paper S stacked on the paper feed tray 21 toward the transport unit 10. And a paper feed roller 22 as a feed roller.
The paper feed unit 20 also has a housing 23 that supports a paper feed tray 21 and a paper feed roller 22.
The sheet feeding unit 20 also rotates the sheet feeding roller 22 so as to match the recording liquid ejection timing in the heads 61Y, 61M, 61C, 61BK, 61T, and feeds the transfer sheet S. Etc.

  The cleaning device 40 is provided for removing and cleaning the recording liquid remaining on the intermediate transfer body 37, that is, on the primary image forming surface, from the intermediate transfer body 37 after the recording liquid is transferred to the transfer paper S. It has been. Therefore, the cleaning device 40 is on the downstream side of the transfer unit 31 in the A1 direction and on the upstream side of the position where the applying device 73 faces the intermediate transfer member 37 and applies the processing liquid to the intermediate transfer member 37. The intermediate transfer member 37 is cleaned.

The cleaning device 40 has a cleaning blade (not shown) as an insulating cleaning member that contacts the intermediate transfer member 37 and cleans the recording liquid on the intermediate transfer member 37. The cleaning blade scrapes away the recording liquid and the processing liquid on the surface of the intermediate transfer body 37, specifically, the recording liquid and the processing liquid remaining after the transfer, by contacting a part, that is, the tip of the cleaning blade. It is sufficient to have such a function, and it has wear resistance.
The cleaning device 40 can be omitted when there is no influence by the recording liquid and processing liquid remaining on the intermediate transfer body 37 or paper dust from the transfer paper S, or when such influence is negligible. It is.

  The applying device 73 functions as a processing liquid application unit that contacts the intermediate transfer body 37 and applies the processing liquid to the intermediate transfer body 37 in a coating mode. The applying device 73 is downstream of the position where the cleaning device 40 cleans the intermediate transfer body 37 in the A1 direction, and upstream of the position where the heads 61Y, 61M, 61C, 61BK, 61T discharge the recording liquid to the intermediate transfer body 37. On the side, it faces the intermediate transfer member 37. The applying device 73 applies the processing liquid to the intermediate transfer member 37 at this position.

The applying device 73 has a coating roller 74 that is a processing liquid coating roller as a processing liquid coating member that contacts the intermediate transfer member 37 at this position and applies the processing liquid.
The applying device 73 also includes a processing liquid tank 75 that is a processing liquid supply member serving as a processing liquid supply unit that stores the processing liquid and supplies the stored processing liquid to the application roller 74.
The applying device 73 is also a coating amount adjusting device as a processing liquid coating amount adjusting means for changing the position of the coating roller 74 with respect to the intermediate transfer body 37 in order to change the coating amount of the processing liquid with respect to the intermediate transfer body 37 by the coating roller 74. 76.

  The application roller 74 has at least a peripheral surface formed of an elastic member, and is provided in a state where a part thereof is immersed in the processing liquid stored in the processing liquid tank 75. The application roller 74 is in contact with the intermediate transfer body 37 with a width corresponding to the already described image formable region in the main scanning direction, ie, the direction perpendicular to the paper surface in FIG.

  The application amount adjusting device 76 changes the position of the application roller 74 with respect to the intermediate transfer body 37 while keeping the application roller 74 in contact with the intermediate transfer body 37, and thereby the application roller 74 with respect to the intermediate transfer body 37. Change the contact force. As a result, the amount of the processing liquid adhering to the surface of the application roller 74 that is transferred to the intermediate transfer body 37, that is, the application amount changes. Specifically, the closer the position of the application roller 74 to the intermediate transfer body 37 and the stronger the contact force of the application roller 74 to the intermediate transfer body 37, the greater the amount of treatment liquid applied.

  The position of the application roller 74 with respect to the intermediate transfer member 37, that is, the gap between the intermediate transfer member 37 and the application roller 74, in other words, the application amount adjustment device 76 for adjusting the application amount of the processing liquid to the intermediate transfer member 37. The driving is controlled by the control unit 98. In this regard, the control unit 98 functions as a processing liquid application control unit that controls the applying device 73. The control unit 98 functioning as a processing liquid amount control unit drives the coating amount adjusting device 76 based on the environmental temperature and the environmental humidity detected by the environment detection sensor 35, and the amount of the processing liquid applied to the intermediate transfer body 37. To control. Therefore, the control unit 98 functioning as the processing liquid amount control means stores a table corresponding to the environmental temperature and environmental humidity detected by the environment detection sensor 35 in advance, and drives the application amount adjusting device 76 according to this table. It is supposed to be.

  The coating amount adjusting device 76 can be omitted when the environmental temperature and the environmental humidity do not affect the processing liquid coating amount or when such effects are negligible. When the application amount adjusting device 76 is omitted, the environment detection sensor 35 can also be omitted.

  The application roller 74 is in contact with the intermediate transfer body 37 with a width corresponding to the image formable area in the main scanning direction, that is, the direction perpendicular to the paper surface in FIG. In addition, a cleaning blade (not shown) is provided as a processing liquid region control mechanism that controls the application region of the processing liquid by the image region detection sensor (not shown) already described. The application area in the main scanning direction is adjusted by changing the length of the cleaning blade in contact with the application roller 74, and the application area in the sub-scanning direction is adjusted by changing the timing of contact with the application roller 74.

  The applying device 73 may include a drive source such as a motor that drives the application roller 74 to rotate in the same direction as the A1 direction at a position facing the intermediate transfer body 37. The control unit 98 that functions as a treatment liquid application control unit controls the configuration in which the driving is controlled in the application device 73 such as the drive source in addition to the application amount adjusting device 76.

The treatment liquid application member is not limited to a member that forms a roller like the application roller 74 and applies the roller application as long as it contacts the intermediate transfer body 37 and applies the treatment liquid, but is not limited to a wire bar, a flade coater, or a treatment liquid. A foam or the like impregnated with may be used.
Further, regarding the supply of the processing liquid from the processing liquid tank 75 to the coating roller 74, the supply via a plurality of rollers such as a pumping roller for pumping up the processing liquid from the processing liquid tank 75 and a leveling roller for leveling coating unevenness. A mechanism may be provided.

Next, the processing liquid applied to the intermediate transfer member 37 by the applying device 73 and the hydrophilic polymer contained in a dispersed state in the processing liquid will be described.
The base of such treatment liquid is a nonpolar solvent that is incompatible with the aqueous phase, that is, phase-separated from the aqueous phase at room temperature. The treatment liquid is obtained by emulsifying a water phase containing a hydrophilic polymer and the non-polar solvent and polar solvent incompatible with the water phase using a surfactant. That is, the treatment liquid has a form in which a water phase containing a hydrophilic polymer is dispersed into a W / O emulsion using a surfactant with the nonpolar solvent and the polar solvent as a continuous phase. Yes. In addition, let this surfactant be a 1st surfactant.

In addition, the treatment liquid is prepared by combining a water phase (dispersed phase) containing a hydrophilic polymer and a continuous phase containing the non-polar solvent incompatible with the water phase with a first surfactant. After emulsification as / O emulsion, it is preferably prepared by adding a polar solvent incompatible with the dispersed phase.
According to this, by adding a polar solvent to the continuous phase of the W / O emulsion, the affinity between the continuous phase and water can be increased without affecting the emulsified state. / W emulsion is likely to cause phase inversion, ink absorption into the hydrophilic polymer is promoted, ink thickening is accelerated, and image bleeding is suppressed. For this reason, even when plain paper is used as the recording medium, feathering, bleeding, and curling are suppressed, uniform application is easy, and a high-quality image is obtained using a processing solution that is relatively easy to store. It is possible to provide an image forming apparatus capable of achieving the above.

As shown in FIG. 2 (a), in this embodiment, the treatment liquid is such that the aqueous phase containing the hydrophilic polymer becomes the aqueous dispersion phase 91, and the nonpolar solvent and the polar solvent become the oily continuous phase 92. Yes.
As shown in FIG. 2A, a state in which an aqueous phase containing an aqueous solvent and the like is emulsified and dispersed in an oil phase of a nonpolar solvent and a polar solvent is referred to as a W / O emulsion.
On the other hand, as shown in FIG. 2C, a state where the aqueous solvent is emulsified and dispersed as the aqueous continuous phase 93 and the nonpolar solvent and the polar solvent are emulsified and dispersed as the oily dispersed phase 94 is referred to as an O / W emulsion. FIG. 2 (b) shows the phase inversion from the W / O emulsion of FIG. 2 (a) to the O / W emulsion of FIG. 2 (c) in a state where both the aqueous phase and the oil phase are continuous phases. It goes through this state in the process.

  In the image forming apparatus 100, an aqueous recording liquid is used as the recording liquid, and the recording liquid is discharged from the heads 61Y, 61M, 61C, 61BK, 61T, and the discharged recording liquid and the processing liquid are brought into contact with each other. And by this contact, the W / O emulsion shown to Fig.2 (a) inverts to the O / W emulsion shown to FIG.2 (c). In the state of the W / O emulsion, the hydrophilic polymer is encapsulated and dispersed in the aqueous phase, so the viscosity as the processing liquid is low. However, when the phase is changed to the O / W emulsion by contact with the aqueous recording liquid, the viscosity increases. Demonstrates viscous action.

The hydrophilic polymer increases the viscosity of the aqueous continuous phase 93 in FIG. 2C, in other words, the aqueous component of the recording liquid, and causes bleeding on the intermediate transfer body 37 and bleeding on the transfer sheet S after transfer. It has a function to prevent or suppress.
In addition, when the hydrophilic polymer is a polymer electrolyte having a dissociable ionic group and is a water-absorbing polymer having a three-dimensionally crosslinked structure, the water-absorbing effect of the aqueous recording liquid is high. The thickening is promoted, the function of preventing or suppressing bleeding is enhanced, and the movement of the aqueous component of the aqueous recording liquid to the transfer paper S can be suppressed, so that curling and cockling are prevented or suppressed.

  The nonpolar solvent is not particularly limited as long as it is phase-separated from an aqueous solvent at room temperature. For example, the hydrocarbons are paraffinic hydrocarbons, naphthene hydrocarbons, olefin hydrocarbons, acetylene hydrocarbons. Examples thereof include hydrogen and silicones. These may be used singly or in combination of two or more.

  Examples of hydrocarbons include dodecane, isododecane, hexadecane, isohexadecane, liquid paraffin, squalane, squalene, polybutene, and polyisobutylene. Examples of silicones include dimethylpolysiloxane, cyclomethicone, diphenylpolysiloxane, and alkylpolysiloxane.

  The ratio of the nonpolar solvent in the treatment liquid is preferably 10% by weight or more, and more preferably 25% by weight or more from the viewpoint of coating leveling due to the treatment liquid viscosity and transferability from the intermediate transfer member 37 to the recording paper S. . Moreover, from a viewpoint of a bleeding prevention effect, 50 weight% or less is preferable and 35 weight% or less is more preferable.

  The hydrophilic polymer used in the treatment liquid is not particularly limited, but is preferably cationic or basic when an ionic colorant and / or ionic resin described later in the recording liquid is anionic. When the ionic colorant and / or ionic resin described later in the recording liquid is cationic, the hydrophilic polymer used in the treatment liquid is preferably anionic or acidic. The hydrophilic polymer used in the treatment liquid may be nonionic.

The cationic hydrophilic polymer is not particularly limited as long as it has a cationic group in the molecule.
Specific examples of the cationic hydrophilic polymer include polyallylamine and its salt, polyvinylamine and its salt, polyethyleneimine and its salt, cationic epoxy, allylamine-maleic acid copolymer and its salt, polydimethylmethylene chloride. Peridinium and salts thereof, dimethyldiallylammonium chloride-acrylamide copolymer and salts thereof, polyacryloyloxyethyltrimethylammonium salt, polymethacryloyloxyethyltrimethylammonium salt, polyacrylamidepropyltrimethylammonium salt, polymethacrylamidopropyltrimethylammonium salt, Polydiethylaminoethyl acrylate and its salt, Polydiethylaminoethyl methacrylate and its salt, Vinylpyrrolidone N, N-dimethylaminoethyl Tacrylic acid copolymer and salt thereof, N-vinylpyrrolidone N, N-dimethylaminoethyl methacrylate copolymer and salt thereof, specially modified polyacrylic acid ester and salt thereof, polydicyandiamide and salt thereof, polyamine condensate and salt thereof Etc. These may be used singly or in combination of two or more.

The anionic hydrophilic polymer is not particularly limited as long as it has an anionic group in the molecule.
Specific examples of the anionic hydrophilic polymer include polyacrylate, polystyrene sulfonate, polyacrylamide methylpropane sulfonate, alginate, starch glycolate and the like. These may be used singly or in combination of two or more.

The nonionic hydrophilic polymer is not particularly limited.
Specific examples of the nonionic hydrophilic polymer include polyacrylamide, polyethylene oxide, polyvinyl alcohol, polyvinyl pyrrolidone, polyisopropylacrylamide, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and the like. These may be used singly or in combination of two or more.

  The ratio of these hydrophilic polymers in the treatment liquid is preferably 30% by weight or more, and more preferably 40% by weight or more from the viewpoint of the effect of preventing bleeding. Moreover, from a viewpoint of the coating leveling property by a process liquid viscosity, 70 weight% or less is preferable and 60 weight% or less is more preferable.

In order to emulsify an aqueous phase containing a hydrophilic polymer in a nonpolar solvent, a highly lipophilic surfactant is preferably used. The term “surfactant having high lipophilicity” as used herein means a surfactant having an HLB value (Hydrophile-Lipophile Balance) of 7 or less.
Examples of such surfactants include glyceryl fatty acid esters such as glyceryl monostearate, glyceryl monooleate, diglyceryl monostearate and diglyceryl monoisostearate, glycol fatty acid esters such as propylene glycol monostearate, and sorbitan monostearate. Sorbitan fatty acid esters such as sorbitan monooleate, and sucrose stearate. These may be used singly or in combination of two or more.

  The polar solvent is not particularly limited as long as it is phase-separated from an aqueous solvent at room temperature and is compatible with the continuous phase composed of the nonpolar solvent. For example, higher fatty acids include isostearic acid, oleic acid, Palmitic acid, lauric acid, myristic acid, behenic acid, linoleic acid, linolenic acid and the like, particularly those in a liquid state such as oleic acid are preferred. Higher alcohols include isostearyl alcohol, oleyl alcohol, octyldodecanol, cholesterol, stearyl alcohol, cetyl alcohol, decyltetradecanol, hexyldecanol, behenyl alcohol, lauryl alcohol, lanolin alcohol, myristyl alcohol, batyl alcohol, etc. Those in a liquid state at room temperature such as alcohol are preferred. Ester oils include isopropyl myristate, isopropyl palmitate, cetyl octanoate, octyldodecyl myristate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyl decyl dimethyloctanoate, cetyl lactate, lanolin acetate , Isocetyl stearate, isocetyl isostearate, di-2-ethylhexyl sebacate, di-2-hexyldecyl myristate, di-2-hexyldecyl palmitate, di-2-hexyldecyl adipate, diisopropyl sebacate, myristyl lactate Cholesteryl 12-hydroxystearate, dipentaerythritol fatty acid ester, monoisostearic acid-N-alkyl glycol, neopentyl glycol dicaprate, apple Diisostearyl, di-2-ethylhexyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, dibutyl sebacate, diisobutyl adipate, isotridecyl stearate, butyl myristate, ethyl myristate , Ethyl hexanoate, methyl myristate, methyl laurate, 2-ethylhexyl stearate, ethyl octanoate, isobutyl octoate, isopropyl octoate, methyl octoate, amyl laurate, butyl laurate, ethyl laurate, isoamyl laurate , Isobutyl laurate, dibutyl adipate, diethyl adipate, diisodecyl adipate, dimethyl adipate, dipropyl adipate, hexyldecyl isostearate, myristine Isocetyl, ethylhexyl palmitate, isopropyl isostearate, isostearyl palmitate, ethylhexyl stearate, ethyl linoleate, isopropyl linoleate, and salicylic butyl octyl and the like, particularly preferably those of the liquid state at room temperature such as diisobutyl adipate. Further, it may be vegetable oil such as olive oil, palm oil, rapeseed oil, sesame oil or linseed oil, or animal oil such as beef tallow. In particular, ester oils having an excellent balance between the emulsion stability and the effect of promoting phase inversion are preferred.

  By using ester oil that shows a liquid state at room temperature, it becomes easier to cause phase inversion to the O / W emulsion while stably forming the W / O emulsion, and ink absorption into the hydrophilic polymer is promoted to increase the ink. Viscosity increases and image blurring is suppressed. For this reason, even when plain paper is used as the recording medium, feathering, bleeding, and curling are suppressed, uniform application is easy, and a high-quality image is obtained using a processing solution that is relatively easy to store. It is possible to provide an image forming apparatus capable of achieving the above.

  The said polar solvent may be used independently and may be used in mixture of 2 or more types. The ratio of these polar solvents in the treatment liquid is preferably 10% by weight or more, and more preferably 20% by weight or more from the viewpoint of the effect of promoting phase inversion. Moreover, from a viewpoint of the emulsification state stability of W / O emulsion, 40 weight% or less is preferable and 30 weight% or less is more preferable.

Further, it is preferable to add a highly hydrophilic surfactant (addition of a second surfactant) in order to further promote phase inversion when the recording liquid and the processing liquid come into contact with each other. The addition of the highly hydrophilic surfactant may be performed on at least one of the recording liquid and the processing liquid, but is preferably performed on the processing liquid.
By adding this second surfactant, the dispersion state changes efficiently when the recording liquid and the processing liquid are mixed, that is, the phase inversion from W / O to O / W is more likely to occur. Even when plain paper is used as the recording medium, feathering, bleeding and curling are suppressed, uniform coating is easy, and a high-quality image can be obtained using a processing solution that is relatively easy to store. An image forming apparatus can be provided.

  As the second surfactant, it is desirable to use a surfactant having an HLB value of 8 or more. However, when the HLB value is too high, bubbles tend to be generated in the recording liquid in the head. The HLB value is most preferably 8-15.

  As such surfactants, POE (4.2) lauryl ether, POE (40) hydrogenated castor oil, POE (10) cetyl ether, POE (9) lauryl ether, POE (10) oleyl ether, monooleic acid POE (20 ) Sorbitan, monolauric acid POE (6) sorbit, POE (15) cetyl ether, monopalmitic acid POE (20) sorbitan, POE (15) oleyl ether, POE (100) hydrogenated castor oil, POE (20) POP (4) Cetyl ether, POE (20) cetyl ether, POE (20) oleyl ether, POE (20) stearyl ether, POE (50) oleyl ether, POE (25) cetyl ether, POE (25) lauryl ether, POE (30) cetyl Ether, POE (40) Chirueteru, and the like. These may be used singly or in combination of two or more.

The aqueous solvent is not particularly limited as long as it is phase-separated from a nonpolar solvent at room temperature.
Specific examples of the aqueous solvent include water, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4 -Butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, 1,2,4-butanetriol Polyhydric alcohols such as 1,2,3-butanetriol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl Polyethers such as ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, N- Nitrogen-containing heterocyclic compounds such as methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, formamide, N-methylformamide, N, N- Amides such as dimethylformamide, amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine, dimethyls And sulfur-containing compounds such as sulfoxide, sulfolane and thiodiethanol, propylene carbonate, ethylene carbonate, and γ-butyrolactone. These may be used singly or in combination of two or more.

  The carriage 62 is integral with the heads 61Y, 61M, 61C, 61BK, 61T and is detachable from the main body 99. This is because when the heads 61Y, 61M, 61C, 61BK, 61T are deteriorated or the like, these can be replaced with new ones, and maintenance is facilitated. Each of the heads 61Y, 61M, 61C, 61BK, 61T can be independently attached to and detached from the main body 99 so that it can be replaced with a new one when deterioration or the like occurs, and for easy maintenance. It has become. This facilitates replacement work and maintenance work.

  The ink discharge devices 60Y, 60M, 60C, 60BK, and 60T have substantially the same configuration with respect to the other points although the colors and compositions of the recording liquids used are different. Each of the ink ejection devices 60Y, 60M, 60C, 60BK, and 60T has a plurality of heads 61Y, 61M, 61C, 61BK, and 61T arranged in parallel in the main scanning direction. Therefore, the ink ejection devices 60Y, 60M, 60C, 60BK, 60T and the image forming apparatus 100 are of a full line type.

The ink ejection devices 60Y, 60M, 60C, 60BK, and 60T are provided with ink cartridges 81Y, 81M, 81C, 81BK, and 81T containing recording liquids of the corresponding colors supplied to the plurality of heads 61Y, 61M, 61C, 61BK, and 61T. Have.
The ink ejection devices 60Y, 60M, 60C, 60BK, and 60T also have a pump (not shown) as a supply pump for pumping and feeding the recording liquid toward the heads 61Y, 61M, 61C, 61BK, and 61T. Yes.

The ink discharge devices 60Y, 60M, 60C, 60BK, and 60T also have a distributor tank (not shown) that distributes and supplies the recording liquid supplied by the pump to the heads 61Y, 61M, 61C, 61BK, and 61T. Yes.
The ink ejection devices 60Y, 60M, 60C, 60BK, and 60T also serve as ink amount detection means that are recording liquid amount detection means for detecting the recording liquid amount in order to detect the shortage of the recording liquid amount in the distributor tank. An ink amount detection sensor (not shown) is included.

The ink ejection devices 60Y, 60M, 60C, 60BK, and 60T also have pipes (not shown) that form a recording liquid feeding path between the ink cartridges 81Y, 81M, 81C, 81BK, and 81T and the distributor tank together with a pump. Have.
The ink ejection devices 60Y, 60M, 60C, 60BK, and 60T also have pipes (not shown) that form recording liquid feeding paths between the distributor tank and the heads 61Y, 61M, 61C, 61BK, and 61T. ing.

  Ink cartridges 81Y, 81M, 81C, 81BK, 81T can be replaced with new ones when the internal recording liquid is consumed and the remaining amount is low or no longer, and for easy maintenance. The main body 99 is detachable. The ink cartridges 81Y, 81M, 81C, 81BK, 81T function as recording liquid cartridges as main tanks.

  The operation of the pump is controlled by the control unit 98, and the recording liquid stored in the ink cartridges 81Y, 81M, 81C, 81BK, and 81T is supplied to each head 61Y, 61M, 61C, 61BK, and 61T. Specifically, the pump stops the discharge of the recording liquid by the heads 61Y, 61M, 61C, 61BK, 61T on the condition that the ink amount detection sensor detects the shortage of the recording liquid amount in the distributor tank. Driven when you are. By this driving, the recording liquid in the ink cartridges 81Y, 81M, 81C, 81BK, 81T is supplied to a distributor tank as a distributor as an ink supply section which is a recording liquid supply section. This driving continues until such a deficiency is no longer detected.

  In this respect, the control unit 98 functions as an ink supply control unit that is a recording liquid supply control unit. In addition, the control unit 98 controls the driving of the image forming apparatus 100 even when not specifically described.

Although not shown, each head 61Y, 61M, 61C, 61BK, 61T has a nozzle plate and minute nozzles formed on the nozzle plate on the recording liquid discharge side facing the intermediate transfer body 37. .
The heads 61Y, 61M, 61C, 61BK, and 61T are not shown in the figure, but are actuators driven based on image signals for discharging the recording liquid from the nozzles to be discharged and landed on the intermediate transfer body 37. As a piezo-type movable actuator.
This movable actuator applies pressure to the recording liquid in the liquid chamber by the displacement of the piezo element, and discharges the recording liquid from the nozzle. However, the movable actuator may be another type of movable actuator.

In addition, each of the heads 61Y, 61M, 61C, 61BK, and 61T uses a heating film boiling method such as a thermal method in which a recording liquid is discharged from a nozzle by applying pressure to the recording liquid in a liquid chamber by bubbles generated by heater heating. Also good.
In any case, each of the heads 61Y, 61M, 61C, 61BK, 61T is driven in accordance with an image signal, and forms an image by applying a recording liquid to the transfer paper S via the intermediate transfer body 37.

A number of nozzles are provided in each of the heads 61Y, 61M, 61C, 61BK, and 61T.
The recording liquid ejected from the heads 61Y, 61M, 61C, 61BK, 61T will be described. All of the recording liquids ejected from the heads 61Y, 61M, 61C, 61BK, and 61T are aqueous recording liquids in which the main component of the solvent is water.
However, the recording liquid ejected from the heads 61Y, 61M, 61C, and 61BK contains a colorant, and the recording liquid ejected from the head 61T does not contain a colorant. In this respect, the heads 61Y, 61M, 61C, and 61BK function as a first head that discharges an aqueous recording liquid containing a colorant, and the head 61T discharges an aqueous recording liquid that does not contain a colorant. It functions as a head.

  As the colorant, that is, the colorant of the recording liquid corresponding to yellow, magenta, cyan, and black, an anionic dye, a cationic dye, a pigment dispersed with an anionic dispersant or a cationic dispersant, and other colored emulsions Is mentioned.

Specific examples of the anionic dye include, for example, dyes classified into acid dyes, food dyes, direct dyes and reactive dyes in the color index. More specifically, examples of acid dyes and food dyes include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142 C.I. I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254, 289 C.I. I. Acid Blue 9, 29, 45, 92, 249 C.I. I. Acid Black 1, 2, 7, 24, 26, 94 C.I. I. Food Yellow 3, 4 C.I. I. Food Red 7, 9, 14 C.I. I. Food black 1, 2 etc. are mentioned.

  In addition, as a direct dye, C.I. I. Direct Yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144 C.I. I. Direct Red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227 C.I. I. Direct Orange 26, 29, 62, 102 C.I. I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202 C.I. I. Direct black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171 etc. are mentioned.

  Further, as reactive dyes, C.I. I. Reactive. Black 3, 4, 7, 11, 12, 17, C.I. I. Reactive. Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47, 51, 55, 65, 67, C.I. I. Reactive. Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55, 60, 66, 74, 79, 96, 97, C.I. I. Reactive. Blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95 etc. are mentioned.

Examples of the cationic dye include basic dyes and cationic dyes.
More specifically, as a basic dye, C.I. I. Basic Blue 9, 12, 26, C.I. I. Basic Red 2, 5, 9, C.I. I. Basic black 2 etc. are mentioned. Further, as a cationic dye, G.I. Yellow GL 200, Red BL 200 R-46, Blue GRL-NB41, etc. are mentioned.

Examples of the pigment used as the colorant for the recording liquid include inorganic pigments and organic pigments.
Examples of inorganic pigments include white pigments such as titanium oxide, zinc oxide, and barium sulfate, and black pigments such as iron oxide.
Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, Thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelates, acidic dye chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like.
Further, a colorant such as carbon black produced by a known method such as a contact method, a furnace method, or a thermal method may be used as a pigment.

  More specifically, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 81, 83 (Disazo Yellow HR) ), 95, 97, 98, 100, 101, 104, 408, 109, 110, 117, 120, 138, 153, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48: 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63 : 1, 63: 2, 64: 1, 81 (Rhodamine 6G rake), 83, 88, 101 (Bengara), 104, 105, 106, 108 (Cadmium red), 112, 114, 122 (Quinacridone magenta), 123 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, CI. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

In the case of using a recording liquid containing a pigment as a colorant, for example, carbon black having a carboxyl group introduced by an oxidation reaction, a radical generated from a diazonium salt containing a carboxyl group or a sulfonic acid group, and carbon black, phthalocyanine, quinacridone Self-dispersing pigments made by reacting pigments such as, self-dispersing pigments made by reacting carbon black, phthalocyanine, quinacridone and other radical initiators containing carboxyl groups and sulfonic acid groups, and functional groups of pigments A pigment in which an ionic group, particularly a carboxyl group is bonded by a covalent bond, such as a self-dispersing pigment obtained by reacting a carboxylic acid anhydride with a carboxylic acid, is preferably used.
These pigments maintain an extremely stable dispersion state in a liquid medium mainly composed of water, and are excellent in storage stability and clogging resistance of the recording liquid.

  When a pigment is used as the colorant, an anionic polymer dispersant or a pigment dispersed with a cationic polymer dispersant can be used instead of the above self-dispersing pigment.

  Examples of the polymeric dispersant having an anionic group include polyacrylic acid and its salt, polymethacrylic acid and its salt, acrylic acid-acrylonitrile copolymer and its salt, acrylic acid-acrylic acid alkyl ester copolymer and its Salt, styrene-acrylic acid copolymer and salt thereof, styrene-methacrylic acid copolymer and salt thereof, styrene-acrylic acid-alkyl acrylate copolymer and salt thereof, styrene-methacrylic acid-alkyl acrylate copolymer Polymer and salt thereof, styrene-α methylstyrene-acrylic acid copolymer and salt thereof, styrene-α methylstyrene-acrylic acid copolymer-acrylic acid alkyl ester copolymer and salt thereof, styrene-maleic acid copolymer Copolymers and salts thereof, vinylnaphthalene-maleic acid copolymers and salts thereof, acetic acid Examples thereof include vinyl-ethylene copolymers and salts thereof, vinyl acetate-crotonic acid copolymers and salts thereof, vinyl acetate-acrylic acid copolymers and salts thereof, and β-naphthalenesulfonic acid formalin condensate.

Examples of the polymer dispersant having a cationic group include aliphatic amine salts.
An anionic surfactant is also preferably used as a pigment dispersant.
Specifically, oleic acid and its salt, lauric acid and its salt, behenic acid and its salt, stearic acid and its salt, such fatty acid and its salt, dodecylsulfonic acid and its salt, decylsulfonic acid and its Salts, alkyl sulfonic acids and salts thereof, alkyl sulfates such as lauryl sulfate and oleyl sulfate, dodecylbenzene sulfonic acid and salts thereof, lauryl benzene sulfonic acid and salts thereof, and alkyl benzene sulfonic acids and the like And salts thereof, dioctylsulfosuccinic acid and salts thereof, dihexylsulfosuccinic acid and salts thereof, dialkylsulfosuccinic acid and salts thereof, naphthylsulfonic acid and salts thereof, naphthylcarboxylic acid and salts thereof, and the like. Aromatic anionic surfactant, polyoxyethylene alkyl ether acetate, polio Dispersion in which pigments are dispersed with fluorine-based anionic surfactants such as silethylene alkyl ether phosphates, polyoxyethylene alkyl ether sulfonates, fluorinated alkyl carboxylic acids and salts thereof, and fluorinated alkyl sulfonic acids and salts thereof As an agent.

  In the case of using a recording liquid in which a pigment is dispersed, the particle diameter of the pigment is not particularly limited, but it is preferable to use a pigment having a particle diameter having a maximum frequency of 20 to 150 nm in terms of the maximum number. When the particle diameter exceeds 150 nm, not only the dispersion stability of the pigment as the recording liquid is lowered, but also the ejection stability of the recording liquid is lowered, and the image quality such as the image density is lowered, which is not preferable. On the other hand, when the particle diameter is less than 20 nm, the storage stability of the recording liquid and the ejection characteristics from the head are stable, and high image quality can be obtained when the processing liquid is used. However, it is not preferable to disperse to such a fine particle size because the dispersion operation and classification operation become complicated and it is difficult to reduce the cost of the recording liquid.

Other preferable examples of the colorant used for the recording liquid include colored resin fine particles such as fine particles obtained by coating a pigment with a resin and fine particles of a dyed resin.
Colored resin fine particles are acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, acrylic-silicone resin, butadiene resin, styrene resin, polyester resin, polyurethane. The resin is colored with an oily dye, a disperse dye or a pigment.

These colored resin fine particles have an advantage that the transfer rate from the intermediate transfer body 37 to the transfer paper S in the transfer process is improved, although it depends on the minimum film forming temperature. If the film is heated to a temperature equal to or higher than the minimum film-forming temperature in the transfer step, a printed matter having a high transfer rate and good gloss, light resistance, water resistance, and scratch resistance can be obtained.
It is preferable to add these colorant components in the recording liquid so as to be 1 to 20% by weight of the recording liquid, and more preferably in the range of 2 to 10% by weight.

Further, resin fine particles not containing a colorant may be used in combination with the recording liquid. A colorant discharged from the head 61T is preferably used for a recording liquid containing no colorant.
Resin components include acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, acrylic-silicone resin, butadiene resin, styrene resin, polyester resin, polyurethane Based resins and the like. The particle diameter of these non-colored resin fine particles is preferably about 150 nm or less, more preferably about 5 to 100 nm.

  Examples of commercially available non-colored resin fine particles include Microgel E-1002, E-5002 (styrene-acrylic resin fine particles, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin fine particles, manufactured by Dainippon Ink & Chemicals, Inc.). Boncoat 5454 (styrene-acrylic resin fine particles, manufactured by Dainippon Ink & Chemicals, Inc.), SAE-1014 (styrene-acrylic resin fine particles, manufactured by Nippon Zeon), Cybinol SK-200 (acrylic resin fine particles, Seiden Chemical Co., Ltd.) Manufactured) and the like.

The non-colored resin fine particles in the recording liquid are preferably added so that the resin component is 0.1 to 20% by weight of the recording liquid, and more preferably in the range of 1 to 10% by weight.
These non-colored resin fine particles are effective in transferability, image gloss and scratch resistance, similarly to the color resin fine particles described above.

  The recording liquid uses water as the main liquid solvent, but is moistened to make the recording liquid have the desired physical properties or to prevent clogging of the nozzles of the heads 61Y, 61M, 61C, 61BK, 61T due to the drying of the recording liquid. It is preferable to use a water-soluble organic solvent as the agent.

  Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4 -Butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, 1,2,4-butanetriol Polyhydric alcohols such as 1,2,3-butanetriol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono Polyhydric alcohol alkyl ethers such as chill ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, N- Nitrogen-containing heterocyclic compounds such as methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, formamide, N-methylformamide, N, N- Amides such as dimethylformamide, amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine, dimethyl Examples thereof include sulfur-containing compounds such as sulfoxide, sulfolane and thiodiethanol, propylene carbonate, ethylene carbonate, and γ-butyrolactone.

  These solvents are used alone or in combination with water. Although there is no restriction | limiting in particular about content of these water-soluble organic solvents, Preferably it uses 1 to 60 weight% of the whole recording liquid, More preferably, it uses in the range of 10 to 40 weight%.

In addition, the recording liquid may contain additives such as a pH adjusting agent, a viscosity adjusting agent, a preservative, and an antioxidant.
Examples of the pH adjuster include hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, lithium carbonate, Examples thereof include alkali metal carbonates such as sodium carbonate and potassium carbonate, amines such as diethanolamine and triethanolamine, boric acid, nitric acid, sulfuric acid and acetic acid.

The preferred range of physical properties of the recording liquid is a pH of 6 to 12 and a surface tension of 10 to 60 mN / m at around 25 degrees. In order to accelerate the absorption of the aqueous component of the recording liquid into the dispersed phase 91 and prevent bleeding, the viscosity is preferably as low as possible, 20 mPa · s or less, and more preferably 5 mPa · s or less.
The recording liquid used in the head 61T is a recording liquid that does not contain a colorant in the recording liquid having the above-described composition.

  In the image forming apparatus 100 having such a configuration, the intermediate transfer body 37 starts to rotate in the A1 direction while facing the heads 61Y, 61M, 61C, 61BK in response to the input of a predetermined signal indicating the start of image formation. . The application roller 74 is driven to rotate by this rotation, and the application roller 74 that is rotated by the rotation rotates the image forming area on the surface of the intermediate transfer body 37 or the area corresponding to the image area detected by the image area detection sensor. Treatment liquid is applied.

  The surface of the intermediate transfer body 37 coated with the processing liquid moves in the A1 direction and reaches a region facing the heads 61Y, 61M, 61C, 61BK. Then, yellow, magenta, cyan, and black recording liquids are ejected from the heads 61Y, 61M, 61C, and 61BK that function as the first head while the intermediate transfer member 37 rotates in the A1 direction, and the intermediate transfer is performed. An image is temporarily carried on the body 37.

At this time, the discharge of the recording liquid is sequentially superposed at different timings from the upstream side to the downstream side in the A1 direction so that the image areas of yellow, magenta, cyan, and black are superimposed on the same position of the intermediate transfer body 37. In a manner. An image area formed by superimposing the recording liquids of the respective colors becomes an image portion which is a first area.
Further, the recording liquid containing no colorant is ejected from the head 61T functioning as the second head to the second region which is the non-image portion which is the reversal region of the image portion. The inversion area of the image portion does not necessarily need to be the entire image formable area, but is an image area examined by the image area detection sensor, that is, a treatment liquid application area.

  The contact between the recording liquid and the processing liquid increases the viscosity of the mixture of the recording liquid and the processing liquid. The processing liquid is an intermediate transfer member in a state of a relatively low viscosity W / O emulsion before such thickening occurs. Therefore, the coating amount is adjusted well by the coating amount adjusting device 76, and the coating state on the surface of the intermediate transfer member 37 is uniform. Further, since the state of the W / O emulsion is relatively stable, there is little change in quality until it is applied to the intermediate transfer body 37 and thickening occurs, and the storage state in the processing liquid tank 75 or on the application roller 74 is good. A reaction such as thickening is obtained by the landing of the recording liquid. Therefore, such a reaction occurs uniformly, there is little unevenness, image disturbance is prevented or suppressed, image density and color reproducibility are ensured, and high-definition and high-quality image formation is performed.

  Whether or not the processing liquid layer remains after the reaction due to the landing of the recording liquid depends on the layer thickness of the processing liquid applied to the intermediate transfer member 37 before the recording liquid is landed, in other words, the coating amount of the processing liquid and the total discharge of the recording liquid. By quantity. In this respect, in this embodiment, the coating thickness adjusting device 76 controls the layer thickness of the processing liquid formed on the surface of the intermediate transfer body 37, that is, the thickness of the processing liquid layer, so that the processing liquid layer remains after the reaction.

  One transfer sheet S fed from the sheet feeding unit 20 is supplied to the transfer unit 31 by the registration roller 34 in accordance with the timing when the leading edge of the image carried on the intermediate transfer body 37 reaches the transfer unit 31. The At the timing when the leading edge of the transfer sheet S enters the transfer unit 31, the transfer roller 38 that has been separated from the intermediate transfer body 37 moves toward the intermediate transfer body 37, and the transfer sheet is placed between the transfer sheet 37 and the intermediate transfer body 37. S is sandwiched. In this state, while the transfer roller 38 rotates with the intermediate transfer member 37, the transfer sheet S passing through the transfer unit 31 is pressed against the intermediate transfer member 37 and is carried on the intermediate transfer member 37. The image on the transfer paper S is transferred.

An image is formed on the transfer paper S by this transfer process. This transfer step is performed by the above-described reaction layer having an image being peeled off from the base processing liquid layer by the low polar solvent, separated from the processing liquid layer, and attached to the transfer paper S. Therefore, the transfer roller 38 transfers the recording liquid whose viscosity has been increased by the phase inversion reaction from the intermediate transfer body 37 to the transfer paper S.
Therefore, not only plain paper but also offset coated paper or film is used as the transfer paper S, image transfer does not occur in the transfer process, and feathering, bleeding, curling, and cockling can be prevented. It is suppressed.

  Furthermore, since the reaction layer whose viscosity is increased by the phase inversion reaction is peeled off from the low-viscosity treatment liquid layer based on the nonpolar solvent, the transfer rate of the recording liquid from the intermediate transfer body 37 to the transfer paper S is high. Therefore, the cleaning of the intermediate transfer member 37 by the cleaning device 40 may not always be performed. In this case, the durability of the cleaning member and the intermediate transfer body 37 can be improved by configuring the cleaning member to contact and separate from the intermediate transfer body 37 in a timely manner. Further, according to this configuration, the removal amount of the processing liquid by cleaning is reduced, and accordingly, the supply amount of the processing liquid to the intermediate transfer body 37 by the applying device 73 may be reduced, so that the consumption amount of the processing liquid is reduced. Saved.

Note that the cleaning device 40 may be omitted when the transfer rate of the recording liquid from the intermediate transfer member 37 to the transfer sheet S is so high that the cleaning of the intermediate transfer member 37 by the cleaning device 40 is not required.
These advantages are that, as described above, the thickness of the processing liquid layer formed on the surface of the intermediate transfer body 37 by the coating amount adjusting device 76, that is, the thickness of the processing liquid layer is controlled to the extent that the processing liquid layer remains after the phase inversion reaction. However, the thickness is not limited to this.

The transfer sheet S on which an image is formed by transfer is fed by the rotation of the intermediate transfer body 37 and the transfer roller 38, guided to the paper discharge table 25, and stacked on the paper discharge table 25. At this time, curling and cockling are prevented or suppressed, and the stacked state of the transfer paper S on the paper discharge tray 25 is good, and the subsequent handling is facilitated.
On the other hand, the intermediate transfer member 37 has a consumption amount of processing liquid due to the transfer of the reaction layer to the transfer sheet S as it rotates in the A1 direction, and a removal amount of the processing liquid when the cleaning device 40 performs cleaning. Accordingly, the processing liquid is applied and supplied by the application roller 74.

  In addition, the image forming apparatus 100 also provides the following advantages. That is, in order to perform high-speed image formation, it is necessary to increase the penetration speed of the recording liquid into the transfer paper S. In this case, the recording liquid penetrates deep into the transfer paper S. For this reason, the back side is unsuitable for double-sided image formation, and also causes curling and cockling. Although it is conceivable to increase the penetrating power of the transfer paper S, the paper type compatibility of the transfer paper S is impaired. In that respect, the penetration of the recording liquid into the transfer paper S is reduced due to the thickening due to the phase inversion reaction of the processing liquid, so that settling, curling and cockling are prevented or suppressed, and the paper type compatibility is impaired. It will never happen. The image forming method according to the present invention is also suitable for double-sided image formation.

The image forming apparatus 100 may be provided with a heating and drying means as necessary.
The heat drying means are installed at a position downstream of the head 61T and upstream of the transfer unit 31, inside the intermediate transfer member 37, inside the transfer roller 38, downstream of the transfer unit 31 and upstream of the paper discharge table 25. You may provide in any position or several places.

  The image forming apparatus 100 described above is an indirect type image forming apparatus using the intermediate transfer member 37 as a recording medium. The recording medium is finally an image such as plain paper as described below. It may be a medium to be formed.

FIG. 3 shows an outline of an example of an image forming apparatus to which the present invention is applied and using a sheet S that is a recording sheet such as plain paper as a recording medium.
In this image forming apparatus 100, the same components as those provided in the image forming apparatus 100 shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted as appropriate, and the image forming apparatus 100 shown in FIG. Differences will be mainly described.

  The image forming apparatus 100 illustrated in FIG. 3 does not include the intermediate transfer member 37 and the transfer roller 38 included in the image forming apparatus 100 illustrated in FIG. In addition, the image forming apparatus 100 shown in FIG. 3 directly forms an image on the sheet S in the recording liquid ejection section 53 where the heads 61Y, 61M, 61C, 61BK, 61T and the guide plate 39 face each other. As described above, the image forming apparatus 100 shown in FIG. 3 is a direct image forming apparatus.

  The image forming apparatus 100 shown in FIG. 3 does not include the intermediate transfer body 37 and the transfer roller 38 provided in the image forming apparatus 100 shown in FIG. I have. However, the pressure application unit 70 can be omitted. The image forming apparatus 100 illustrated in FIG. 1 may include a pressure applying unit 70 on the downstream side of the transfer unit 31 and on the upstream side of the paper discharge tray 25 in the transport direction of the paper S.

  The pressure application unit 70 is disposed on the downstream side of the discharge unit 53 and on the upstream side of the paper discharge tray 25 in the transport direction of the paper S. The pressure application unit 70 includes pressure rollers 71 and 72 that are in pressure contact with each other, and a motor (not shown) that rotationally drives the pressure roller 71 and causes the pressure roller 72 to be driven to rotate by the pressure roller 71. The pressure application unit 70 is configured to pass the sheet S to which the recording liquid is applied in the discharge unit 53 between the pressure rollers 71 and 72. The pressure between the pressure rollers 71 and 72 is the same as the pressure between the transfer roller 38 and the intermediate transfer body 37 in a state where they are in pressure contact with each other.

  In the image forming apparatus 100 having such a configuration, the sheet S fed from the sheet feeding unit 20 is fed toward the applying device 73 in response to the input of a predetermined signal indicating the start of image formation. . After the sheet S passes through the transport roller 32, the application liquid is applied by the applying device 73 to the image formable area on the side to which the recording liquid is applied in the discharge unit 53. Next, the sheet S is supplied to the discharge unit 53 at a timing by the registration roller 34. Then, as the sheet S passes through the ejection unit 53, the heads 61Y, 61M, 61C, and 61BK are applied to the image formable area where the processing liquid is applied, as in the image forming apparatus 100 illustrated in FIG. , 61T, the recording liquid is discharged.

  When the recording liquid lands on the processing liquid, the above-described phase inversion reaction occurs, and a reaction layer having an image is formed on the paper S. The applying device 73 applies a sufficient amount of processing liquid necessary to cause a phase inversion reaction to the paper S by the coating amount adjusting device 76, but when this is difficult to control, the phase inversion reaction is surely generated. Therefore, a larger amount of processing liquid than that amount of processing liquid is applied to the paper S.

Other advantages similar to those of the image forming apparatus shown in FIG. 1 are obtained as follows, for example. That is, since the penetration of the recording liquid into the transfer paper S is reduced by the increase in the viscosity of the recording liquid, such a set-off is prevented or suppressed, which is suitable for double-sided image formation. Further, there is an advantage that deformation such as cockling and curling of the paper S is suppressed or prevented. In addition, this advantage is advantageous in that handling of the transfer sheet S is facilitated, such as improved transportability of the transfer sheet S carrying an image and prevention or suppression of jamming.
In addition, when the sheet S on which an image is formed in the ejection unit 53 passes through the pressure applying unit 70, pressure is applied together with the recording liquid, thereby improving the fixing property of the recording liquid on the sheet S and recording. It is possible to improve the smoothness of the liquid dots and to improve the glossiness of the image.

  In each of the image forming apparatuses 100 described above, the processing liquid is applied to the intermediate transfer body 37 or the paper S that is a recording medium by the applying device 73, and then the recording liquid is supplied by the heads 61Y, 61M, 61C, 61BK, and 61T. It uses a pre-painted configuration that allows it to discharge and land.

This pre-coating configuration is a post-coating configuration in which the recording liquid is ejected and landed on the intermediate transfer body 37 or the paper S by the heads 61Y, 61M, 61C, 61BK, 61T, and then applied with the processing liquid by the applying device 73. Compared to this, there is an advantage that the image is hardly disturbed and the image quality is improved.
In other words, when post-coating is performed in the indirect method, the recording liquid may be disturbed when the recording liquid is landed on the intermediate transfer body 37 that is a recording medium, and then, when the processing liquid is applied. Also, the image may be disturbed. Further, when post-coating is performed in the direct method, the image may be disturbed due to bleeding of the recording liquid when the recording liquid is landed on the recording sheet S, and the image is also applied when the processing liquid is applied thereafter. Disturbance can occur.
However, if, for example, the application device 73 employs a configuration in which the processing liquid is ejected by the head, the image is not contacted, so that image disturbance during application of the processing liquid can be suppressed. Even when the recording medium is the sheet S, there is no problem even in the post-coating configuration when the recording medium is a dedicated sheet or the like that hardly causes the recording liquid to bleed.

Employing a configuration in which the processing liquid is discharged by the head also provides the following advantages.
That is, it is possible to apply the treatment liquid only to the first region and to strictly control the application amount of the treatment liquid, thereby obtaining an advantage that the consumption amount of the treatment liquid is reduced.
Further, by applying the treatment liquid only to the first area, the second head for landing the recording liquid not containing the colorant on the treatment liquid in the second area becomes unnecessary, and the second head is omitted. Advantages of downsizing the device, facilitating control, and reducing the cost are obtained. Further, since the recording liquid for the second head is not necessary, an advantage that the running cost is reduced can be obtained.

  Even when the configuration in which the processing liquid is discharged by the head is not employed, the second head can be omitted. In this case, the reaction layer is formed only in the image portion, that is, the first region, and the treatment liquid layer exists in the non-image portion. In this case, the processing liquid adheres to the transfer paper S and the paper S, but since the processing liquid is based on a nonpolar solvent, curling and cockling are prevented or suppressed.

Using the processing liquid and the recording liquid in consideration of the above conditions, how the image formation is performed by the following experiment,
Each item of (1) character quality (2) bleeding (3) dot reproducibility (4) curl (5) transferability was examined.

<Criteria>
The criteria for the items (1) to (5) are as follows.
(1) Character quality Black characters were evaluated. Visually, the case where the feathering was not conspicuous was marked with ◎, the case where the feathering was not so conspicuous was marked with ○, and the one less than that was marked with ×.
(2) Bleeding An image in which each color of black, yellow, magenta, and cyan was solidly adjacent was evaluated. Visually, the inconspicuous bleeding at the boundary part of each color was marked with 、, the inconspicuous one with ◯, and the lower one with x.
(3) Dot reproducibility Dots of each color of black, yellow, magenta, and cyan were evaluated. Under microscopic observation (magnification 500 times), the dot shape was a perfect circle and clean, and 少 し was slightly broken.
(4) Curled black A4 solid was evaluated. After printing, the height of the edge of the paper was evaluated after 10 seconds with the printing surface facing down. A paper having a height of 10 mm or less from the paper installation surface was marked with ◎, a paper that was rounded into a cylindrical shape was marked with ×, and a paper in between was marked with ◯.
(5) Transferability When the black solid image used in item (4) is transferred from the intermediate transfer sheet to the transfer paper S, the image remaining on the intermediate transfer sheet is peeled off with Printac C (manufactured by Nitto Denko). And pasted on my paper. This image density was measured with a reflection densitometer (X-rite 939, manufactured by X-rite). The case of 0.2 or less was marked with ◎, and the case of more than that was marked with ×.

Image forming conditions relating to Examples 1 to 9 and Comparative Examples 1 to 3 are shown below.
<Image formation conditions (direct printing method)>
A predetermined amount of processing liquid sample is applied in advance from an ink jet head (made by Ricoh) 61BK, 61C, 61M, 61Y in which recording liquids (black, cyan, magenta, yellow, made by Ricoh) are arranged at 1200 dpi in the main scanning direction. The paper was discharged onto the paper S (made by Ricoh, My Paper). The moving speed of the paper S was 850 mm / s. The discharge of the recording liquid containing no colorant was omitted.
The evaluations (1) to (4) were performed from the evaluation image on the paper S (the evaluation of (5) was not performed because of the direct printing method).

Image forming conditions relating to Examples 10 to 18 and Comparative Examples 4 to 6 are shown below.
<Image formation conditions (indirect printing method)>
Inkjet heads (manufactured by Ricoh) 61BK, 61C, 61M in which recording liquids (black, cyan, magenta, yellow, manufactured by Ricoh), whose composition and weight ratio are adjusted as described below, are arranged at 1200 dpi in the main scanning direction. 61Y was discharged onto an intermediate transfer sheet on which a predetermined amount of the treatment liquid sample had been applied in advance, and transferred onto transfer paper S (Ricor, My Paper) fixed to the transfer roller 38. As the intermediate transfer member (intermediate transfer sheet), a PFA-coated rubber sheet having a thickness of 5 mm was used, and the moving speed was set to 850 mm / s. The discharge of the recording liquid containing no colorant was omitted.
The evaluations (1) to (4) were evaluated from the evaluation image on the transfer paper S, and the evaluation (5) was performed from the remaining image on the intermediate transfer sheet.

[Example 1]
The treatment liquid is as follows.
<Processing liquid>
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pharmaceutical Co., Ltd.), 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods Co., Ltd., HLB 2), 80 parts by weight of isostearic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) Emulsification was performed with a homodisper and an ultrasonic homogenizer to obtain a W / O emulsion. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours in an argon atmosphere, and this was treated as treatment liquid 1 and applied onto a sheet S with a roller so that the coating amount was 100 mg / A4. Then, an evaluation image was formed.

The recording liquid is as follows.
<Black recording liquid>
-Sulfonic acid group-bonded carbon black pigment dispersion (CAB-O-JET-200, solid content 20% by weight, manufactured by Cabot Specialty Chemicals, Inc.): 35.0% by weight
2-pyrrolidone: 10.0% by weight
・ Glycerin: 14.0% by weight
Propylene glycol monobutyl ether: 0.9% by weight
・ Sodium dehydroacetate: 0.1% by weight
Distilled water: remaining amount Subsequently, the pH was adjusted to 9.1 with a 5 wt% aqueous solution of lithium hydroxide, and pressure filtration was performed with a membrane filter having an average pore diameter of 0.8 µm.

<Yellow recording liquid>
Sulfonic acid group-bonded yellow pigment dispersion (CAB-O-JET-270Y, solid content 10% by weight, manufactured by Cabot Specialty Chemicals Inc.): 40.0% by weight
Triethylene glycol: 15.0% by weight
・ Glycerin: 25.0% by weight
Propylene glycol monobutyl ether: 6.0% by weight
-Dehydroacetic acid soda: 0.1 wt%
Distilled water: remaining amount Subsequently, the pH was adjusted to 9.1 with a 5 wt% aqueous solution of lithium hydroxide, and pressure filtration was performed with a membrane filter having an average pore diameter of 0.8 µm.

<Magenta recording liquid>
-Sulfonic acid group-bonded magenta pigment dispersion (CAB-O-JET-260M, solid content 10% by weight, manufactured by Cabot Specialty Chemicals, Inc.): 40.0% by weight
Diethylene glycol: 20.0% by weight
Propylene glycol monobutyl ether: 3.0% by weight
・ Sodium dehydroacetate: 0.1% by weight
Distilled water: remaining amount Subsequently, the pH was adjusted to 9.1 with a 5 wt% aqueous solution of lithium hydroxide, and pressure filtration was performed with a membrane filter having an average pore diameter of 0.8 µm.

<Cyan recording liquid>
-Sulfonic acid group-bonded cyan pigment dispersion (CAB-O-JET-250C, solid content 10% by weight, manufactured by Cabot Specialty Chemicals, Inc.): 40.0% by weight
・ Ethylene glycol: 4.0% by weight
Triethylene glycol: 14.0% by weight
Propylene glycol monobutyl ether: 6.0% by weight
・ Sodium dehydroacetate: 0.1% by weight
Distilled water: remaining amount Subsequently, the pH was adjusted to 9.1 with a 5 wt% aqueous solution of lithium hydroxide, and pressure filtration was performed with a membrane filter having an average pore diameter of 0.8 µm.

[Example 2]
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere. 40 parts by weight of the W / O emulsion after the polymerization reaction and 10 parts by weight of isostearic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) are mixed, and this is treated liquid 2 so that the coating amount on the paper S is 100 mg / A4. An image for evaluation was formed after coating with a roller.

Example 3
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pharmaceutical Co., Ltd.), 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB 2), 80 parts by weight of dibutyl sebacate (manufactured by Tokyo Chemical Industry Co., Ltd.) The emulsion was emulsified with a homodisper and an ultrasonic homogenizer to obtain a W / O emulsion. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours in an argon atmosphere, and this was treated as treatment liquid 3 and applied onto a sheet S with a roller so that the coating amount was 100 mg / A4. Then, an evaluation image was formed.

Example 4
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pharmaceutical Co., Ltd., 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB approx. 2), 80 parts by weight of diisobutyl adipate (manufactured by Tokyo Chemical Industry Co., Ltd.) The emulsion was emulsified with a homodisper and an ultrasonic homogenizer to obtain a W / O emulsion. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours in an argon atmosphere, and this was treated as treatment liquid 4 and applied onto a sheet S with a roller so that the coating amount was 100 mg / A4. Then, an evaluation image was formed.

Example 5
40 parts by weight of Senka Act Gel CM100 (polymethacrylate-based cationic polymer-containing W / O emulsion, solid content of about 35%, manufactured by Senka) and 10 parts by weight of dibutyl sebacate (Tokyo Chemical Industry) are mixed. Then, using this as the treatment liquid 5, an evaluation image was formed on the paper S by applying it with a roller so that the coating amount was 100 mg / A4.

Example 6
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere.
40 parts by weight of the W / O emulsion after the polymerization reaction and 10 parts by weight of dibutyl sebacate (manufactured by Tokyo Chemical Industry Co., Ltd.) are mixed, and this is treated liquid 6 so that the coating amount on paper S is 100 mg / A4. An image for evaluation was formed after coating with a roller.

Example 7
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere.
40 parts by weight of the W / O emulsion after the polymerization reaction and 10 parts by weight of diisobutyl adipate (manufactured by Tokyo Chemical Industry Co., Ltd.) are mixed, and this is treated liquid 7 so that the coating amount is 100 mg / A4 on the paper S. An image for evaluation was formed after coating with a roller.

Example 8
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere. 40 parts by weight of the W / O emulsion after the polymerization reaction, 10 parts by weight of dibutyl sebacate (manufactured by Tokyo Chemical Industry Co., Ltd.), 2 parts by weight of hydrophilic surfactant BT-12 (manufactured by Nikko Chemicals, HLB14,5) are mixed. Then, using this as the treatment liquid 8, an evaluation image was formed on the paper S by applying the roller so that the coating amount was 100 mg / A4.

Example 9
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere. 40 parts by weight of the W / O emulsion after the polymerization reaction, 10 parts by weight of diisobutyl adipate (manufactured by Tokyo Chemical Industry Co., Ltd.), 2 parts by weight of hydrophilic surfactant BT-12 (manufactured by Nikko Chemicals, HLB 14, 5) are mixed. Then, using this as the treatment liquid 9, an evaluation image was formed on the paper S by applying a roller so that the coating amount was 100 mg / A4.

[Comparative Example 1]
An image for evaluation was formed on the paper S without applying the treatment liquid on the paper S.

[Comparative Example 2]
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere.
This W / O emulsion was used as the treatment liquid A, and an image for evaluation was formed on a paper S so as to have a coating amount of 100 mg / A4.

[Comparative Example 3]
Dissolve 120 parts by weight of 3-methacrylamidopropyltrimethylammonium chloride in 50 parts by weight of water, 10 parts by weight of 1% by weight methylenebisacrylamide aqueous solution, polymerization initiator VA-046B (manufactured by Wako Pure Chemical Industries, Ltd.), liquid paraffin (Japanese 120 parts by weight of Kojun Pure Chemical Industries, Ltd.) and 9 parts by weight of lipophilic surfactant ER-290 (manufactured by Mitsubishi Chemical Foods, HLB of about 2) are added, emulsified with a homodisper and an ultrasonic homogenizer, and W / An O emulsion was obtained. After purging with argon for 30 minutes, polymerization was performed at 60 ° C. for 3 hours under an argon atmosphere. 40 parts by weight of the W / O emulsion after the polymerization reaction, 10 parts by weight of liquid paraffin (manufactured by Wako Pure Chemical Industries), and 2 parts by weight of a hydrophilic surfactant BT-12 (manufactured by Nikko Chemicals, HLB14,5) were mixed. . Using this as the processing liquid B, an image for evaluation was formed on the paper S by applying a roller so that the coating amount was 100 mg / A4.

Example 10
The treatment liquid 1 was applied on a roller so that the coating amount was 100 mg / A4 on an intermediate transfer sheet, and an image for evaluation was formed.

Example 11
The treatment liquid 2 was applied on a roller so that the coating amount was 100 mg / A4 on the intermediate transfer sheet, and an evaluation image was formed.

Example 12
The treatment liquid 3 was applied onto the intermediate transfer sheet with a roller so that the coating amount was 100 mg / A4, and then an evaluation image was formed.

Example 13
The treatment liquid 4 was applied onto the intermediate transfer sheet with a roller so that the coating amount was 100 mg / A4, and an evaluation image was formed.

Example 14
The treatment liquid 5 was applied on a roller so that the coating amount was 100 mg / A4 on an intermediate transfer sheet, and an image for evaluation was formed.

Example 15
The treatment liquid 6 was applied onto the intermediate transfer sheet with a roller so that the coating amount was 100 mg / A4, and an evaluation image was formed.

Example 16
The treatment liquid 7 was applied onto the intermediate transfer sheet with a roller so that the coating amount was 100 mg / A4, and an evaluation image was formed.

Example 17
The treatment liquid 8 was applied onto the intermediate transfer sheet with a roller so that the coating amount was 100 mg / A4, and an evaluation image was formed.

Example 18
The treatment liquid 9 was applied onto the intermediate transfer sheet by a roller so that the coating amount was 100 mg / A4, and an evaluation image was formed.

[Comparative Example 4]
An image for evaluation was formed without applying the treatment liquid on the intermediate transfer sheet.

[Comparative Example 5]
The treatment liquid A was applied on a roller so that the coating amount was 100 mg / A4 on the intermediate transfer sheet, and an image for evaluation was formed.

[Comparative Example 6]
The treatment liquid B was applied on a roller so that the coating amount was 100 mg / A4 on the intermediate transfer sheet, and an image for evaluation was formed.

<Evaluation results>
The evaluation results of these examples and comparative examples are summarized in Table 1.

  From the above results, by including a polar solvent incompatible with the dispersed phase in the continuous phase of the W / O emulsion, a good image in which image bleeding such as feathering and bleeding is further suppressed is obtained. It was confirmed to be obtained by an image forming apparatus.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.
For example, the image forming apparatus to which the present invention is applied is not limited to the type of image forming apparatus described above, but may be another type of image forming apparatus. In other words, the image forming apparatus may be a copying machine, a single facsimile, or a multifunction machine such as these, a multifunction machine such as a monochrome machine related thereto, or other image forming apparatus used for forming an electric circuit. Further, it may be an image forming apparatus used for forming a predetermined image in the biotechnology field.

The intermediate transfer member may not be a roller but may be an endless belt.
In the direct image forming apparatus, the recording medium may be conveyed by an endless belt-like member.

  The number of heads is increased or decreased according to the application of the image forming apparatus, and may be plural or one. When the number of heads is plural, the head is not limited to four as in the above-described configuration example, and a head that discharges more kinds of recording liquids, for example, light-colored recording liquids such as light cyan and light magenta may be provided. It is sufficient that at least one of the first head and the second head is provided according to the function of the image forming apparatus.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

DESCRIPTION OF SYMBOLS 10 Conveyance unit 20 Paper feed unit 21 Paper feed tray 22 Paper feed roller 23 Case 25 Discharge stand 31 Transfer part 32 Transfer roller 34 Registration roller 35 Environment detection sensor 36 Transfer device 37 Recorded body, intermediate transfer body 37a Support body 37b Surface layer 38 Transfer roller 39 Guide plate 40 Cleaning device 53 Ejection section 60Y, 60M, 60C, 60BK, 60T Ink ejection device 61Y, 61M, 61C, 61BK, 61T Head 61Y, 61M, 61C, 61BK First head 62 Carriage 70 Pressure application unit 71, 72 Pressure roller 73 Application means 74 Application roller 75 Treatment liquid tank 76 Application amount adjustment device 77 Contact / separation device 78 Cleaning device 81Y, 81M, 81C, 81BK, 81T Ink cartridge 91 Water-soluble polymer 92 Water 93 Low polarity solvent 94 first interface Activator 98 Treatment liquid amount control means 99 Main body 100 Image forming apparatus S Recording medium, recording paper

JP 2003-82265 A JP 2003-246135 A JP 2000-343808 A JP 2014-073675 A

Claims (5)

In an image forming apparatus comprising: a head that discharges an aqueous recording liquid onto a recording medium; and a processing liquid applying unit that applies a processing liquid to the recording medium.
The treatment liquid is made into a W / O emulsion by the first surfactant, the dispersed phase contains at least a hydrophilic polymer, the continuous phase is at least a nonpolar solvent incompatible with the dispersed phase, and the dispersed phase. And an incompatible polar solvent.   The treatment liquid emulsifies a dispersed phase containing at least a hydrophilic polymer and a continuous phase containing a nonpolar solvent incompatible with the dispersed phase as a W / O emulsion with a first surfactant. The image forming apparatus according to claim 1, wherein an incompatible polar solvent is added to the dispersed phase after the dispersion.   The image forming apparatus according to claim 1, wherein the polar solvent is an ester oil that exhibits a liquid state at room temperature.   The said processing liquid further contains the water-soluble 2nd surfactant which accelerates | stimulates the phase inversion of the emulsification state of this processing liquid from the said W / O emulsion to O / W emulsion. The image forming apparatus according to any one of the above.   5. The recording medium according to claim 1, further comprising a transfer unit that transfers the aqueous recording liquid and the processing liquid on the intermediate transfer body to a recording medium. The image forming apparatus described