JP2015100927A - Image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method by which, in an embodiment thereof, blurring and inducing a feeling for a residual liquid can be suppressed, and an image forming apparatus.SOLUTION: The image forming method includes the steps of: applying a first solvent S to an elastic member E1; discharging an inkjet ink I to deposit on the first solvent S applied to the elastic member E1; transferring the inkjet ink I depositing on the first solvent S onto an elastic member E2; and transferring the inkjet ink I depositing on the first solvent S, which has been transferred to the elastic member E2, onto paper P. The inkjet ink I comprises a second solvent, and a resin and a coloring material dissolved in the second solvent. The first solvent S can crystallize the resin when the inkjet ink I is dropped thereon and is miscible with the second solvent. A wettability of the surface of the elastic member E2 where the inkjet ink I depositing on the first solvent S is transferred, with respect to the first solvent S is equal to or lower than a wettability of the surface of the elastic member E1 where the first solvent S is applied, with respect to the first solvent S.

Description

  The present invention relates to an image forming method and an image forming apparatus.

  Ink jet ink generally tends to bleed when attached to a recording medium. For example, when ink-jet ink adheres to plain paper, the ink-jet ink diffuses along the fiber lines of pulp, and bleeding tends to occur. When ink jet ink bleeding occurs, the image density decreases and the edge of the image is blurred, which causes image deterioration.

Patent Document 1 discloses an oil-based inkjet printing method in which printing is performed by applying a pretreatment liquid to a print medium and then discharging an oil-based ink containing at least a pigment and a solvent onto the print medium. At this time, the pretreatment liquid includes at least inorganic particles having an average particle diameter of 1 μm or more and 20 μm or less and a solvent, and the solubility parameter (SP value) of the solvent of the pretreatment liquid and the solubility parameter (SP value) of the solvent of the oil-based ink. ) Is 1.0 (cal / cm ³ ) ^1/2 or more.

  However, there is a problem that a feeling of residual liquid occurs.

  An object of one embodiment of the present invention is to provide an image forming method and an image forming apparatus capable of suppressing the occurrence of bleeding and a feeling of residual liquid in view of the problems of the related art.

  In one embodiment of the present invention, in the image forming method, a step of applying a first solvent to the first intermediate transfer member, and a first solvent applied to the first intermediate transfer member by discharging an inkjet ink A step of attaching to the solvent, a step of transferring the inkjet ink attached to the first solvent to the second intermediate transfer member, and an inkjet ink attached to the first solvent transferred to the second intermediate transfer member. The inkjet ink includes a second solvent, a resin dissolved in the second solvent, and a coloring material, and the first solvent removes the inkjet ink. When dropped, the resin can be precipitated and mixed with the second solvent, and the ink jet ink attached to the first solvent of the second intermediate transfer member is transferred. Side The first solvent wettability is the first intermediate transfer member to said first solvent surface is less than the wettability to the first solvent of the surface of the side to be coated.

  In one embodiment of the present invention, in the image forming method, an inkjet ink is ejected onto the first intermediate transfer member, and a step of ejecting the inkjet ink onto the first intermediate transfer member is applied in a non-contact manner. A step of transferring the inkjet ink to which the first solvent is adhered to a second intermediate transfer member, and an inkjet ink to which the first solvent transferred to the second intermediate transfer member is adhered. A step of transferring to a recording medium, wherein the inkjet ink includes a second solvent, a resin and a colorant dissolved in the second solvent, and the first solvent drops the inkjet ink. Then, it is possible to deposit the resin, to be mixed with the second solvent, and for the inkjet ink to which the first solvent of the second intermediate transfer member is attached. Wettability to the first solvent of the surface of the side to be photographed is below wettability to the first solvent of the first of the ink-jet ink for ejecting side surface of the intermediate transfer member.

  According to one aspect of the present invention, in an image forming apparatus, a first intermediate transfer member, a second intermediate transfer member, a coating unit that applies a first solvent to the first intermediate transfer member, and an inkjet ink Discharging means for discharging and adhering to the first solvent applied to the first intermediate transfer member; and first ink for transferring the ink-jet ink attached to the first solvent to the second intermediate transfer member Transfer means, and second transfer means for transferring the inkjet ink attached to the first solvent transferred to the second intermediate transfer body to a recording medium, the inkjet ink comprising a second solvent, A resin and a colorant dissolved in a second solvent are included, and the first solvent can precipitate the resin when the inkjet ink is dropped, and is mixed with the second solvent. Is possible The surface of the intermediate transfer member to which the ink jet ink attached to the first solvent is transferred has wettability with respect to the first solvent on the side of the first intermediate transfer member to which the first solvent is applied. The wettability to the first solvent on the surface of

  According to one aspect of the present invention, in the image forming apparatus, the first intermediate transfer member, the second intermediate transfer member, the first discharge unit that discharges the inkjet ink to the first intermediate transfer member, A non-contact coating of the solvent, and a second ejection means for adhering to the inkjet ink ejected to the first intermediate transfer body, and an inkjet ink to which the first solvent is adhered to the second intermediate transfer body A first transfer means for transferring, and a second transfer means for transferring the inkjet ink, to which the first solvent transferred to the second intermediate transfer body is adhered, to a recording medium. A second solvent, a resin dissolved in the second solvent, and a coloring material, wherein the first solvent is capable of precipitating the resin when the inkjet ink is dropped. Miscible with other solvents And the wettability of the surface of the second intermediate transfer body to which the ink-jet ink attached with the first solvent is transferred to the first solvent is higher than that of the first intermediate transfer body. It is below the wettability with respect to the said 1st solvent of the surface at the side which discharges an inkjet ink.

  According to one embodiment of the present invention, it is possible to provide an image forming method and an image forming apparatus capable of suppressing the occurrence of bleeding and residual liquid feeling.

It is a schematic diagram showing a first embodiment of the image forming method of the present invention. It is a schematic diagram which shows 2nd embodiment of the image forming method of this invention. 1 is a schematic diagram showing a first embodiment of an image forming apparatus of the present invention. It is a schematic diagram which shows 2nd embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows 3rd embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows 4th embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows 5th embodiment of the image forming apparatus of this invention. It is a schematic diagram showing an image forming apparatus of Comparative Example 1-1. It is a schematic diagram showing an image forming apparatus of Comparative Example 1-2. It is a schematic diagram which shows the image forming apparatus of Comparative Example 1-3. It is a schematic diagram which shows the image forming apparatus of Comparative Example 1-4.

  Next, the form for implementing this invention is demonstrated with drawing.

  FIG. 1 shows a first embodiment of the image forming method of the present invention.

  First, the application member 12 in which the sponge 12b impregnated with the first solvent S is fixed to the support plate 12a is moved in contact with the elastic member E1 as the first intermediate transfer member, and the elastic member E1 is moved. The 1st solvent S is apply | coated to the whole surface (refer Fig.1 (a)).

  Next, the inkjet solvent I containing the second solvent, the resin dissolved in the second solvent, and the coloring material is discharged and adhered to the first solvent S applied to the elastic member E1 (FIG. 1). (See (b)). At this time, when the inkjet solvent I is dropped, the first solvent S can precipitate the resin and can be mixed with the second solvent.

  As soon as the inkjet ink I adheres to the first solvent S, the second solvent in the inkjet ink I diffuses into the first solvent S, and the first solvent S and the second solvent are mixed. The solvent S ′ becomes an ink-jet ink I ′ having increased viscosity (see FIG. 1C). At that time, since the resin in the inkjet ink I is not dissolved in the first solvent S, the resin and the coloring material are difficult to diffuse into the first solvent S. As a result, the resin and color material in the inkjet ink I ′ having increased viscosity are less likely to diffuse, and the occurrence of bleeding can be suppressed.

  Further, the ink-jet ink I ′ having increased viscosity is transferred to the elastic member E2 as the second intermediate transfer member (see FIG. 1D). At this time, the wettability with respect to the first solvent S of the surface to which the ink-jet ink I ′ having the increased viscosity of the elastic member E2 is transferred is the first of the surface of the elastic member E1 on the side to which the first solvent S is applied. It is below the wettability with respect to one solvent S. As a result, the mixed solvent S ′ is hardly transferred to the elastic member E2, and the occurrence of a residual liquid feeling can be suppressed. Further, the ink-jet ink I ′ having an increased viscosity is easy to transfer because the mixed solvent S ′ with the elastic member E2 serves as a shielding layer. At this time, the ink jet ink I ′ having increased viscosity transferred to the elastic member E2 can further suppress the occurrence of bleeding because the resin and the coloring material are difficult to diffuse.

  Next, the ink-jet ink I ′ having increased viscosity transferred to the elastic member E2 is transferred to the paper P as a recording medium (see FIG. 1E). Thereafter, the mixed solvent S ′ remaining in the inkjet ink I ′ having increased viscosity transferred to the paper P evaporates or diffuses into the interior of the paper P, so that the resin and coloring material in the inkjet ink I ′ having increased viscosity are obtained. Since the ink remains on the surface of the paper P, the ink-jet ink I ′ having increased viscosity is solidified and fixed on the paper P. As a result, it is possible to form a sharp image with high image density.

  The viscosity at 25 ° C. of the inkjet ink I, the first solvent S, and the second solvent is usually 30 mPa · s or less. Thereby, even if the moving speed of the application member 12 is 500 mm / s or more, the first solvent S is applied so that the unevenness of the thickness of the first solvent S becomes uniform with an average thickness of ± 30% or less. can do. Ink jet ink can be discharged using an ink jet head. Furthermore, the diffusion rate at which the second solvent diffuses into the first solvent S is sufficiently higher than the diffusion rate at which the resin and the coloring material diffuse into the first solvent S. As a result, the second solvent diffuses into the first solvent S before the resin and the color material diffuse into the first solvent S in the state of FIG. A region with increased viscosity is formed in the vicinity of the contact surface with the solvent S, and diffusion of the resin and the coloring material into the first solvent S can be suppressed.

The diffusion coefficient in the diffusion between liquids is usually about 1 × 10 ⁻⁹ m ² / s. If the diffusion coefficient in the diffusion of the second solvent into the first solvent S is also equivalent, the viscosity after the ink-jet ink I adheres to the first solvent S is calculated based on the diffusion equation. It can be seen that the concentration of the first solvent S in the ink-jet ink I ′ having increased is about ten to several tens of milliseconds for the concentration of the first solvent S in the ink-jet ink I to be about half of the concentration of the first solvent S. . Thereby, the viscosity of the inkjet ink I can be increased in a short time.

  The time from when the ink jet ink I adheres to the first solvent S applied to the elastic member E1 to when the ink jet ink I ′ having increased viscosity is transferred to the elastic member E2 is usually the time when the ink jet ink I is the first solvent It is more than the time when the concentration of the second solvent in the inkjet ink I ′ having increased viscosity after adhering to the solvent S is about half of the concentration of the second solvent in the inkjet ink I. Thereby, the occurrence of bleeding can be further suppressed.

The greater the diffusion rate at which the second solvent diffuses into the first solvent S, the more the resin and coloring material diffuse into the first solvent S when the ink-jet ink I adheres to the first solvent S. can do. That is, the diffusion coefficient in the diffusion of the second solvent into the first solvent S is 1 × 10 ⁻⁹ to 1 × 10 ⁻¹¹ m ² / s under the conditions for actually forming an image in the image forming apparatus. It is preferable that At this time, the diffusion coefficient depends on the temperature and the viscosity, and the viscosity depends on the temperature.

The amount of the first solvent S applied to the elastic member E1 is usually 0.02 to 0.3 mg / cm ² and preferably 0.03 to 0.2 mg / cm ² . When the coating amount of the first solvent S on the elastic member E1 is less than 0.02 mg / cm ² , the viscosity of the inkjet ink I attached to the first solvent S may not increase sufficiently, and 0.3 mg / If it exceeds cm ² , a residual liquid feeling may occur on the paper P.

  It is preferable to apply the first solvent S to a region that is substantially the same as the region to which the inkjet ink I of the elastic member E1 is attached. Thereby, the mixed solvent S ′ is further hardly transferred to the elastic member E2, and the occurrence of a residual liquid feeling can be further suppressed. Moreover, the usage-amount of the 1st solvent S can be reduced.

  FIG. 2 shows a second embodiment of the image forming method of the present invention.

  First, an inkjet ink I containing a second solvent, a resin dissolved in the second solvent, and a coloring material is discharged onto the elastic member E1 (see FIG. 2A).

  Next, the first solvent S is applied in a non-contact manner and adhered to the inkjet ink I discharged onto the elastic member E1 (see FIG. 2B).

  As soon as the first solvent S adheres to the inkjet ink I, the second solvent in the inkjet ink I diffuses into the first solvent S, and the first solvent S and the second solvent are mixed. The solvent S ′ becomes an ink jet ink I ′ having an increased viscosity (see FIG. 2C). At that time, since the resin in the inkjet ink I is not dissolved in the first solvent S, the resin and the coloring material are difficult to diffuse into the first solvent S. As a result, the resin and color material in the inkjet ink I ′ having increased viscosity are less likely to diffuse, and the occurrence of bleeding can be suppressed.

  Further, the ink-jet ink I ′ having increased viscosity is transferred to the elastic member E2 (see FIG. 2D). At this time, the wettability with respect to the first solvent S of the surface to which the ink-jet ink I ′ having the increased viscosity of the elastic member E2 is transferred is the first of the surface of the elastic member E1 on the side to which the first solvent S is applied. It is below the wettability with respect to one solvent S. As a result, the mixed solvent S ′ is hardly transferred to the elastic member E2, and the occurrence of a residual liquid feeling can be suppressed. Further, the ink-jet ink I ′ having an increased viscosity is easy to transfer because the mixed solvent S ′ with the elastic member E2 serves as a shielding layer. At this time, the ink jet ink I ′ having increased viscosity transferred to the elastic member E2 can further suppress the occurrence of bleeding because the resin and the coloring material are difficult to diffuse.

  Next, the ink-jet ink I ′ having increased viscosity is transferred to the paper P (see FIG. 2E). Thereafter, the mixed solvent S ′ remaining in the ink-jet ink I ′ having increased viscosity transferred to the paper P evaporates or diffuses into the paper P, so that the ink-jet ink I ′ having increased viscosity is solidified to form the paper P. To settle. As a result, it is possible to form a sharp image with high image density.

  It is preferable that the first solvent S is applied in a non-contact manner in a region that is substantially the same as the region where the inkjet ink I of the elastic member E1 is ejected. Thereby, the mixed solvent S ′ is further hardly transferred to the elastic member E2, and the occurrence of a residual liquid feeling can be further suppressed. Moreover, the usage-amount of the 1st solvent S can be reduced.

  The paper P is not particularly limited, and examples thereof include special paper such as art paper, super art paper, dull art paper, super dull art paper, and coated paper, medium paper, high quality paper, plain paper such as PPC paper, and the like.

  Instead of the paper P, a recording medium such as a PET film, a transparent film such as a polypropylene film, a metal sheet such as an aluminum sheet or a stainless sheet may be used.

  The shape of the elastic member E1 is not particularly limited, and examples thereof include a sheet shape, a roller shape, and a belt shape.

  The shape of the elastic member E2 is not particularly limited, and examples thereof include a sheet shape, a roller shape, and a belt shape.

  The viscosity of the inkjet ink I at 25 ° C. is usually about 1 to 20 mPa · s.

  The weight average molecular weight of the resin is usually 2000 to 50000. If the weight average molecular weight of the resin is less than 2000, the viscosity may be difficult to increase even if the content of the second solvent in the inkjet ink I is decreased. May be higher.

  The inkjet ink I may be either oil-based ink or water-based ink.

  The resin for the oil-based ink is not particularly limited, and examples thereof include polystyrene, polyester, epoxy resin, acrylic resin, a copolymer containing these in the skeleton, rosin-modified phenol resin, and alkyd resin.

  The second solvent for the oil-based ink is not particularly limited as long as the resin for the oil-based ink can be dissolved, but dimethyl succinate, diethyl succinate, dibutyl adipate, isobutyl adipate, dibutyl sebacate And fatty acid esters such as ethyl laurate, isopropyl myristate, butyl palmitate and the like.

  The first solvent S for oil-based ink is not particularly limited as long as the resin for oil-based ink does not dissolve and can be mixed with the second solvent for oil-based ink. However, tridecane, tetradecane, pentadecane are not limited. High-boiling paraffinic hydrocarbons such as hexadecane and heptadecane that are liquid at room temperature, high-boiling olefinic hydrocarbons such as pentadecene, hexadecene, and heptadecene, dimethyl silicone oil, and fatty acid ester-modified silicone oil. May be.

  Although it does not specifically limit as resin for water-based ink, Polyvinyl alcohol, polyvinylpyrrolidone, etc. are mentioned.

  The second solvent for the water-based ink is not particularly limited as long as the resin for the water-based ink can be dissolved, and examples thereof include glycols such as glycerin and butylene glycol.

  The first solvent S for water-based ink is not particularly limited as long as the resin for water-based ink does not dissolve and can be mixed with the second solvent for water-based ink, but ethanol, isopropyl alcohol, etc. Alcohols and the like.

  The coloring material may be either a dye or a pigment, but is preferably a pigment because it is difficult to diffuse into the first solvent S.

  The pigment is not particularly limited, but carbon black, phthalocyanine blue, monoazo yellow, disazo yellow, benzimidazole yellow, anthraquinone yellow, polyazo yellow, monoazo red, brilliant carmine 6B, anthraquinone red, dimethylquinacridone, etc. Can be mentioned.

  When a pigment is used as the color material, it is preferable to use a pigment dispersant in order to uniformly disperse it in the second solvent.

  The pigment dispersant is not particularly limited, and examples thereof include an alkyl ammonium type polymer dispersant, a block copolymer type polymer dispersant, and a phosphate ester salt dispersant.

  FIG. 3 shows a first embodiment of the image forming apparatus. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  The image forming apparatus 10 ejects inkjet ink in accordance with an image signal, an intermediate transfer belt 11 as a first intermediate transfer member, an application member 12 that applies a first solvent to the entire surface of the intermediate transfer belt 11, and an image signal. In addition, an inkjet head 13 that attaches the inkjet ink I to the first solvent applied to the intermediate transfer belt 11 is provided. Further, the image forming apparatus 10 includes a pressure roller 15 that transfers the ink-jet ink whose viscosity is increased by the ink-jet ink I adhering to the first solvent to the intermediate transfer roller 14 as a second intermediate transfer member, and the viscosity. A cleaning pad 16 is provided for removing ink jet ink, mixed solvent, paper dust, and the like remaining on the intermediate transfer belt 11 to which the ink jet ink having increased ink is transferred. At this time, the intermediate transfer belt 11 is supported by the pressure roller 15 and the tension rollers 17A and 17B. Further, the image forming apparatus 10 remains on the pressure roller 18 that transfers the inkjet ink having increased viscosity transferred to the intermediate transfer roller 14 to the paper P, and the intermediate transfer roller 14 to which inkjet ink having increased viscosity is transferred. The cleaning pad 19 is used to remove the inkjet ink, the mixed solvent, the paper dust, and the like.

  The intermediate transfer belt 11 has an elastic layer (not shown) formed on a support (not shown).

  The material constituting the support is not particularly limited, but thermoplastic resins such as polyethylene terephthalate, heat resistant resins such as polyimide, polyamideimide, and polyetherketone, and metal materials such as stainless steel, nickel, aluminum, and iron, etc. Can be mentioned.

  The material constituting the elastic layer is not particularly limited as long as the wettability with respect to the inkjet ink I is good, and examples thereof include silicone rubber, NBR rubber, chloroprene rubber, urethane rubber, and fluorine rubber.

  The intermediate transfer roller 14 has an elastic layer 14b formed on a support 14a.

  The material constituting the support 14a is not particularly limited, but is a thermoplastic resin such as polyethylene terephthalate, a heat-resistant resin such as polyimide, polyamideimide, or polyetherketone, or a metal material such as stainless steel, nickel, aluminum, or iron. Is mentioned.

  The material constituting the elastic layer 14b is not particularly limited as long as the wettability with respect to the first solvent is equal to or less than the wettability with respect to the first solvent of the elastic layer formed on the intermediate transfer belt 11, silicone rubber, NBR rubber, chloroprene rubber, urethane rubber, fluororubber and the like can be mentioned.

  The intermediate transfer belt 11 and the intermediate transfer roller 14 may further include a release layer on the elastic layer.

  The material constituting the release layer is not particularly limited, but tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), tetrafluoroethylene- Fluorine such as ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-hexafluoropropylene polymer (FEP), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV) Based resins and the like.

  Further, the intermediate transfer belt 11 and the intermediate transfer roller 14 do not have to be formed with an elastic layer.

  The pressure rollers 15 and 18 have an elastic layer (not shown) formed on a support (not shown).

  The widths of the cleaning pads 16 and 19 are substantially the same as the width of the paper P.

  The inkjet head 13 may be either a shuttle type head that mechanically scans in the sub-scanning direction or a line type head in which all nozzles are arranged in the width direction of the paper P.

  An ink container (not shown) in which inkjet ink is stored is connected to the inkjet head 13 via a tube (not shown) and a pump (not shown).

  Instead of the intermediate transfer roller 14, an intermediate transfer belt supported by a pressure roller and a tension roller may be used.

  Further, instead of the inkjet head 13, an inkjet head that discharges yellow ink, magenta ink, cyan ink, and black ink may be sequentially installed in the scanning direction.

  FIG. 4 shows a second embodiment of the image forming apparatus of the present invention.

  The image forming apparatus 20 has the same configuration as the image forming apparatus 10 except that an ink jet head 21 that discharges the first solvent S to the intermediate transfer belt 11 according to an image signal is used instead of the application member 12. .

  FIG. 5 shows a third embodiment of the image forming apparatus of the present invention.

  The image forming apparatus 30 has the same configuration as the image forming apparatus 10 except that the application member 12 is brought into contact with the application roller 31. At this time, the application roller 31 applies the first solvent to the entire surface of the intermediate transfer belt 11 in a non-contact manner, and adheres the ink to the inkjet ink I discharged onto the intermediate transfer belt 11.

  FIG. 6 shows a fourth embodiment of the image forming apparatus of the present invention.

  The image forming apparatus 40 has the same configuration as the image forming apparatus 20 except that the arrangement of the inkjet head 13 and the inkjet head 21 is reversed. At this time, the inkjet head 21 causes the first solvent to be ejected according to the image signal and adheres to the inkjet ink I ejected onto the intermediate transfer belt 11.

  FIG. 7 shows a fifth embodiment of the image forming apparatus of the present invention.

  The image forming apparatus 50 has the same configuration as the image forming apparatus 10 except that an intermediate transfer roller 51 is used instead of the intermediate transfer belt 11 supported by the pressure roller 15 and the tension rollers 17A and 17B. At this time, the intermediate transfer roller 51 has an elastic layer 51b formed on the support 51a.

  The materials constituting the support 51a and the elastic layer 51b are the same as the materials constituting the support 14a and the elastic layer 14b, respectively.

  In the image forming apparatuses 20, 30, and 40, similarly to the image forming apparatus 50, an intermediate transfer roller 51 is used in place of the pressure roller 15 and the intermediate transfer belt 11 supported by the tension rollers 17A and 17B. May be.

  In the present embodiment, “part” means “part by mass”.

(Example 1-1)
While stirring using a stirrer, 9 parts of low molecular weight polyester Byron 220 (manufactured by Toyobo Co., Ltd.) was dissolved in 82 parts of vinylizer 40 (diisobutyl adipate) (manufactured by Kao Corporation), and then the pigment dispersant DISPERBYK-2155 ( 2 parts (by Big Chemie Japan) were dissolved. Next, the obtained solution, 4 parts of carbon black # 2350 (manufactured by Mitsubishi Chemical Corporation) and zirconia beads having a diameter of 0.3 mm were placed in a container, and then dispersed for 1 hour while being vibrated and stirred using a ball mill. Furthermore, it filtered using the filter with a hole diameter of 0.45 micrometer, and obtained the inkjet ink I. FIG.

  An image was formed using the image forming apparatus 10.

As an inkjet head, a pulse injector PIJ-15NSET (manufactured by Cluster Technology) was used. In addition, Exepar iPM (isopropyl myristate) (manufactured by Kao Corporation) was used as the first solvent, and sponge (manufactured by Toyo Polymer Co., Ltd.) was used as the sponge 12b. Further, as the intermediate transfer belt 11, an elastic made of 0.3 mm thick silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) on a support made of polyimide Kapton 500H (manufactured by DuPont) having a thickness of 0.125 mm. An endless belt having a layer formed thereon was used. Further, as the intermediate transfer roller 14, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3 mm is formed on a columnar support 14a made of aluminum alloy having an outer diameter of 100 mm. Used rollers. Furthermore, as the pressure roller 15, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3 mm is formed on a cylindrical support made of SUS having an outer diameter of 50 mm. A roller was used. In addition, as the pressure roller 18, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3 mm is formed on a cylindrical support made of SUS having an outer diameter of 100 mm. A roller was used. Further, as the paper P, A4 PPC paper Mypaper (manufactured by Ricoh) was used. Further, after applying the first solvent so that the coating amount on the entire surface of the intermediate transfer belt 11 is 0.16 mg / cm ² , the discharge amount of about 8 pL of the inkjet ink I is 0.16 mg / cm ^2. And was attached to the first solvent. Furthermore, the inkjet head 13 and the pressure roller 15 were arranged so that the time from when the inkjet ink I adhered to the first solvent to the transfer of the inkjet ink with increased viscosity was 0.5 seconds. Further, the linear speed of the intermediate transfer belt 11 was set to 500 mm / s.

  At this time, the silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) had a static contact angle with respect to the first solvent of 28 °.

  In addition, one drop of inkjet ink I was dropped with a dropper on a slide glass coated with Exepal iPM (isopropyl myristate) (manufactured by Kao Corporation) in an environment of 25 ° C. and 1 bar. The resin was deposited in the encapsulated state.

  After dropping 1 drop of Vinicizer 40 (diisobutyl adipate) (made by Kao) onto a glass slide coated with Exepal iPM (isopropyl myristate) (made by Kao) under an environment of 25 ° C. and 1 bar. When observed with an optical microscope, Vinicizer 40 (diisobutyl adipate) (manufactured by Kao Corporation) was mixed with Exepal iPM (isopropyl myristate) (manufactured by Kao Corporation).

(Example 1-2)
An image was formed in the same manner as in Example 1-1 except that the image forming apparatus 20 was used instead of the image forming apparatus 10. At this time, about 8 pL of the first solvent was discharged.

(Example 1-3)
An image was formed in the same manner as in Example 1-1 except that the image forming apparatus 30 was used instead of the image forming apparatus 10. At this time, as the application roller 31, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3 mm is formed on a cylindrical support made of SUS having an outer diameter of 50 mm. A roller was used. Further, the first solvent was applied so that the coating amount on the entire surface of the coating roller 31 was 0.32 mg / cm ² . Further, the application roller 31 and the pressure roller 15 are arranged so that the time from when the first solvent adheres to the inkjet ink I to when the inkjet ink with increased viscosity is transferred is 0.5 seconds.

(Example 1-4)
An image was formed in the same manner as in Example 1-1 except that the image forming apparatus 40 was used instead of the image forming apparatus 10. At this time, about 8 pL of the first solvent was discharged. Further, the inkjet head 21 and the pressure roller 15 were arranged so that the time from when the first solvent adhered to the inkjet ink I until the inkjet ink with increased viscosity was transferred was 0.5 seconds.

(Example 1-5)
An image was formed in the same manner as in Example 1-1 except that the image forming apparatus 50 was used instead of the image forming apparatus 10. At this time, as the intermediate transfer roller 51, an elastic layer 51b made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3 mm is formed on a cylindrical support 51a made of aluminum alloy having an outer diameter of 100 mm. Used roller. Further, the linear speed of the intermediate transfer roller 51 was set to 250 mm / s. Furthermore, the inkjet head 13 and the intermediate transfer roller 51 are arranged so that the time from when the inkjet ink I adheres to the first solvent to when the inkjet ink with increased viscosity is transferred is 0.5 seconds.

(Comparative Example 1-1)
An image was formed in the same manner as in Example 1-2 except that the image forming apparatus 60 (see FIG. 8) was used instead of the image forming apparatus 20. At this time, the image forming apparatus 60 includes the inkjet heads 13 and 21 and the conveyance belt 61 that conveys the paper P. Further, the conveyance belt 61 is supported by tension rollers 62A and 62B.

(Comparative Example 1-2)
An image was formed in the same manner as Comparative Example 1-1 except that the image forming apparatus 70 (see FIG. 9) was used instead of the image forming apparatus 60. At this time, the image forming apparatus 70 has the same configuration as the image forming apparatus 60 except that the arrangement of the inkjet head 13 and the inkjet head 21 is reversed.

(Comparative Example 1-3)
An image was formed in the same manner as in Example 1-1 except that the image forming apparatus 80 (see FIG. 10) was used instead of the image forming apparatus 10. At this time, the image forming apparatus 80 has the same configuration as the image forming apparatus 10 except that the intermediate transfer roller 14 is omitted.

(Comparative Example 1-4)
An image was formed in the same manner as in Example 1-3 except that the image forming apparatus 90 (see FIG. 11) was used instead of the image forming apparatus 30. At this time, the image forming apparatus 90 has the same configuration as the image forming apparatus 30 except that the intermediate transfer roller 14 is omitted.

(Static contact angle to the first solvent (wetting))
A state where 10 μL of the first solvent was dropped on the plate-like sample using a micropipette was photographed using a high-speed camera VW-6000 (manufactured by Keyence Corporation). At this time, an image 0.3 seconds after the first solvent contacted the sample was captured, and the static contact angle was calculated by the θ / 2 method.

  Next, bleeding and residual liquid feeling were evaluated.

(Bleed)
The bleeding of the image formed on the paper P was evaluated using an optical microscope. In addition, the case where there was no blur was evaluated as ◯, the case where there was a slight blur as Δ, and the case where there was a significant blur as X.

(Remaining liquid feeling)
The increase in paper weight immediately after the image was formed was measured to evaluate the residual liquid feeling. In addition, the case where the increase in weight was less than 80 mg was evaluated as ◯, the case where it was 80 mg or more and less than 120 mg as Δ, and the case where it was 120 mg or more as ×.

  Table 1 shows the evaluation results of bleeding and residual liquid feeling.

表１から、実施例１−１〜１−５は、滲み及び残液感の発生を抑制できることがわかる。

From Table 1, it can be seen that Examples 1-1 to 1-5 can suppress the occurrence of bleeding and residual liquid feeling.

  On the other hand, in Comparative Examples 1-1 and 1-2, the first intermediate transfer member and the second intermediate transfer member are not used, and thus a residual liquid feeling is generated.

  In Comparative Examples 1-3 and 1-4, the second intermediate transfer member is not used, and thus a residual liquid feeling is generated.

(Example 2-1)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, a polyimide Kapton 500H (manufactured by DuPont) having a thickness of 0.125 mm and an aluminum alloy columnar support 14a having an outer diameter of 100 mm are provided. Using a roller on which an elastic layer 14b made of urethane rubber UTSL-1 (manufactured by MISUMI) having a thickness of 0.3 mm is formed, the coating amount on the entire surface of the intermediate transfer belt 11 is 0.32 mg / cm ^2. Example 1-1, except that after applying the first solvent as described above, about 24 pL of the inkjet ink I was discharged so that the discharge amount was 0.96 mg / cm ² and adhered to the first solvent. In the same manner, an image was formed.

  At this time, polyimide Kapton 500H (manufactured by DuPont) and urethane rubber UTSL-1 (manufactured by Misumi) had static contact angles of 6 ° and 12 ° with respect to the first solvent, respectively.

(Example 2-2)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, a urethane rubber UTSL-1 (Misumi Corp.) having a thickness of 0.3 mm on a support made of polyimide Kapton 500H (DuPont) having a thickness of 0.125 mm, respectively. An image was formed in the same manner as in Example 2-1, except that an endless belt formed with an elastic layer made of SUS304H and a cylindrical support 14a made of SUS304H having an outer diameter of 100 mm were used.

  At this time, SUS304H had a static contact angle with respect to the first solvent of 19 °.

(Example 2-3)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, a thickness of SUS304H STHBLT (made by Misumi) having a thickness of 0.15 mm and a columnar support 14a made of an aluminum alloy having an outer diameter of 100 mm are provided. An image was formed in the same manner as in Example 2-1, except that a roller having an elastic layer 14b made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) with a thickness of 0.3 mm was used.

(Example 2-4)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3mm is formed on a polyimide support having a thickness of 0.125mm. An elastic layer 14b made of Viton EA423PA-4 (manufactured by DuPont) made of fluororubber having a thickness of 0.3 mm is formed on the endless belt and the cylindrical support 14a made of aluminum alloy having an outer diameter of 100 mm. An image was formed in the same manner as in Example 2-1, except that the above roller was used.

  At this time, the fluororubber Viton EA423PA-4 (manufactured by DuPont) had a static contact angle of 81 ° with respect to the first solvent.

(Comparative Example 2-1)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, a urethane rubber UTSL-1 (Misumi Corp.) having a thickness of 0.3 mm on a support made of polyimide Kapton 500H (DuPont) having a thickness of 0.125 mm, respectively. Made of Kapton 500H (manufactured by DuPont) of polyimide having a thickness of 0.125 mm on an endless belt on which an elastic layer made of aluminum is formed and a cylindrical support 14a made of aluminum alloy having an outer diameter of 100 mm. An image was formed in the same manner as in Example 2-1, except that the roller on which the layer was formed was used.

(Comparative Example 2-2)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, a thickness of SUS304H STHBLT (made by Misumi) having a thickness of 0.15 mm and a columnar support 14a made of an aluminum alloy having an outer diameter of 100 mm are provided. An image was formed in the same manner as in Example 2-1, except that a roller having an elastic layer 14b made of urethane rubber UTSL-1 (manufactured by MISUMI) having a thickness of 0.3 mm was used.

(Comparative Example 2-3)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, an elastic layer made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone) having a thickness of 0.3mm is formed on a polyimide support having a thickness of 0.125mm. An image was formed in the same manner as in Example 2-1, except that the endless belt and the cylindrical support 14a made of SUS304H having an outer diameter of 100 mm were used.

(Comparative Example 2-4)
As the intermediate transfer belt 11 and the intermediate transfer roller 14, an elastic layer made of Viton EA423PA-4 (manufactured by DuPont) made of fluororubber having a thickness of 0.3 mm on a polyimide support having a thickness of 0.125 mm. An elastic layer 14b made of silicone rubber KE1353 (manufactured by Shin-Etsu Silicone Co., Ltd.) having a thickness of 0.3 mm is formed on the endless belt on which is formed and the cylindrical support 14a made of aluminum alloy having an outer diameter of 100 mm. An image was formed in the same manner as in Example 2-1, except that the above roller was used.

  Next, bleeding and residual liquid feeling were evaluated.

  Table 2 shows the evaluation results of bleeding and residual liquid feeling.

表２から、実施例２−１〜２−４は、滲み及び残液感の発生を抑制できることがわかる。

From Table 2, it can be seen that Examples 2-1 to 2-4 can suppress the occurrence of bleeding and residual liquid feeling.

  On the other hand, in Comparative Examples 2-1 to 2-4, the material constituting the surface on the side to which the inkjet ink attached to the first solvent of the second intermediate transfer member is transferred is fixed to the first solvent. Since the static contact angle is less than the static contact angle with respect to the first solvent of the material constituting the surface of the first intermediate transfer member to which the first solvent is applied, a residual liquid feeling is generated.

E1, E2 Elastic member I Inkjet ink I ′ Inkjet ink with increased viscosity P Paper S First solvent S ′ Mixed solvent 10, 20, 30, 40, 50 Image forming apparatus 11 Intermediate transfer belt 12 Coating member 12a Support plate 12b Sponge 13, 21 Inkjet head 14, 51 Intermediate transfer roller 14a, 51a Support 14b, 51b Elastic layer 15, 18 Pressure roller 16, 19 Cleaning pad 17A, 17B Tension roller 31 Application roller

JP 2011-143705 A

Claims (8)

Applying a first solvent to the first intermediate transfer member;
Discharging ink jet ink to adhere to the first solvent applied to the first intermediate transfer member;
Transferring the inkjet ink attached to the first solvent to a second intermediate transfer member;
Transferring the inkjet ink attached to the first solvent transferred to the second intermediate transfer member to a recording medium;
The inkjet ink includes a second solvent, a resin and a colorant dissolved in the second solvent,
The first solvent can deposit the resin when the inkjet ink is dropped, and can be mixed with the second solvent.
The wettability with respect to the first solvent of the surface of the second intermediate transfer member to which the ink-jet ink attached to the first solvent is transferred is applied by the first solvent of the first intermediate transfer member. An image forming method, wherein the wettability of the surface on the side to be processed is less than the first solvent.   The image forming method according to claim 1, wherein a region to which the first solvent is applied is substantially the same as a region to which the inkjet ink is attached. Discharging the inkjet ink to the first intermediate transfer member;
Applying the first solvent in a non-contact manner and adhering it to the inkjet ink discharged to the first intermediate transfer member;
Transferring the inkjet ink to which the first solvent is adhered to a second intermediate transfer member;
A step of transferring the inkjet ink to which the first solvent transferred to the second intermediate transfer body is attached to a recording medium;
The inkjet ink includes a second solvent, a resin and a colorant dissolved in the second solvent,
The first solvent can deposit the resin when the inkjet ink is dropped, and can be mixed with the second solvent.
The wettability of the surface of the second intermediate transfer body to which the ink-jet ink to which the first solvent has adhered is transferred to the first solvent is the side of the first intermediate transfer body on which the ink-jet ink is discharged An image forming method, wherein the surface has a wettability with respect to the first solvent.   The image forming method according to claim 3, wherein a region where the first solvent is applied in a non-contact manner is substantially the same as a region where the inkjet ink is ejected. A first intermediate transfer member;
A second intermediate transfer member;
Application means for applying a first solvent to the first intermediate transfer member;
Discharging means for discharging ink-jet ink to adhere to the first solvent applied to the first intermediate transfer member;
First transfer means for transferring the ink-jet ink attached to the first solvent to the second intermediate transfer member;
A second transfer means for transferring the ink-jet ink attached to the first solvent transferred to the second intermediate transfer member to a recording medium;
The inkjet ink includes a second solvent, a resin and a colorant dissolved in the second solvent,
The first solvent can deposit the resin when the inkjet ink is dropped, and can be mixed with the second solvent.
The wettability with respect to the first solvent of the surface of the second intermediate transfer member to which the ink-jet ink attached to the first solvent is transferred is applied by the first solvent of the first intermediate transfer member. An image forming apparatus having a wettability with respect to the first solvent on the surface to be processed is lower than the first solvent.   6. The image forming apparatus according to claim 5, wherein a region to which the first solvent is applied is substantially the same as a region to which the inkjet ink is attached. A first intermediate transfer member;
A second intermediate transfer member;
First ejection means for ejecting inkjet ink onto the first intermediate transfer member;
A second ejection means for applying the first solvent in a non-contact manner and adhering to the inkjet ink ejected to the first intermediate transfer member;
A first transfer means for transferring the ink-jet ink to which the first solvent is adhered to the second intermediate transfer member;
Having a second transfer means for transferring the inkjet ink, to which the first solvent transferred to the second intermediate transfer body is adhered, to a recording medium;
The inkjet ink includes a second solvent, a resin and a colorant dissolved in the second solvent,
The first solvent can deposit the resin when the inkjet ink is dropped, and can be mixed with the second solvent.
The wettability of the surface of the second intermediate transfer body to which the ink-jet ink to which the first solvent has adhered is transferred to the first solvent is the side of the first intermediate transfer body on which the ink-jet ink is discharged An image forming apparatus having a wettability with respect to the first solvent on the surface of the image forming apparatus.   The image forming apparatus according to claim 7, wherein a region where the first solvent is applied in a non-contact manner is substantially the same as a region where the inkjet ink is ejected.

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