JP6295841B2 - Image forming method and image forming apparatus - Google Patents

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 feathering is likely to occur. When ink jet ink bleeding occurs, the image density decreases and the edge of the image is blurred, which causes image deterioration.

  As a method for suppressing image deterioration, there is known an oil-based inkjet printing method in which printing is performed by applying an oil-based ink containing at least a pigment and a solvent onto a print medium after applying a pretreatment liquid to the print medium. (For example, refer to Patent Document 1).

  However, in the conventional technique described above, when an image is formed on a non-permeable recording medium, the image is fixed on the recording medium by an excess solvent contained in a pretreatment liquid or oil-based ink applied to the recording medium. Sexuality may worsen. In addition, when a recording medium on which an image is formed is conveyed, ink may adhere to a paper discharge roller or the like.

  Accordingly, an object of the present invention is to improve the fixability of an image on a recording medium.

In one proposal, an inkjet ink comprising a coating step of applying a first solvent to a recording medium conveyed by a conveying means , a second solvent, and a resin and a colorant dissolved in the second solvent. And an absorption step of absorbing at least one of the first solvent and the second solvent on the recording medium, and a discharging step of adhering to the first solvent applied to the recording medium And a discharging step of discharging the recording medium by the conveying means after the absorption step, and the first solvent can deposit the resin when the inkjet ink is dropped, An image forming method is provided in which the second solvent is miscible with the first solvent.

  According to one aspect, it is possible to improve the fixability of an image on a recording medium.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to a first embodiment. FIG. 4 is a diagram illustrating a schematic configuration of an image forming apparatus according to a second embodiment. FIG. 9 is a diagram illustrating a schematic configuration of an image forming apparatus according to a third embodiment. FIG. 10 is a diagram illustrating a schematic configuration of an image forming apparatus according to a fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[First Embodiment]
First, an image forming apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the first embodiment.

  The image forming apparatus according to the first embodiment includes an application roller 11, a sponge 12, an inkjet head 13, an absorption roller 14, a conveyance roller 15, and a conveyance belt 16.

  For example, the application roller 11 rotates clockwise to apply the first solvent S supplied from the sponge 12 to the recording medium P. The recording medium P is not particularly limited. For example, a transparent film such as a PET film or a polypropylene film, a metal sheet such as an aluminum sheet or a stainless sheet, a plain paper such as a medium quality paper, a high quality paper, or a PPC paper may be used. it can.

  The sponge 12 is impregnated with the first solvent S. The sponge 12 is provided in contact with the application roller 11 and supplies the first solvent S to the application roller 11. The width of the sponge 12 is not particularly limited, but is designed to be substantially the same as the width of the recording medium P, for example.

  The ink jet head 13 is provided on the front side (left side in the drawing) of the recording medium P in the transport direction with respect to the application roller 11, and ejects ink jet ink I according to the image signal to the recording medium P. The inkjet ink I is attached to the applied first solvent S. The type of the inkjet head 13 is not particularly limited, but for example, a shuttle type head or a line type head can be used. An ink container (not shown) containing the inkjet ink I is connected to the inkjet head 13 via a tube (not shown) and a pump (not shown).

  The absorbing roller 14 is provided on the front side (left side in the figure) in the transport direction of the recording medium P with respect to the inkjet head 13. For example, the absorbing roller 14 rotates clockwise to absorb at least one of the first solvent S applied to the recording medium P and the second solvent discharged to the recording medium P. As a result, excess solvent on the recording medium P can be absorbed, so that the viscosity of the inkjet ink I on the recording medium P is increased and the fixability to the recording medium P is improved.

  The absorbing roller 14 is not particularly limited, but is determined according to the type of solvent to be absorbed, that is, the first solvent S and the second solvent.

  Specifically, when oil-based ink is used as the second solvent, it is preferable to use, as the absorbing roller 14, for example, a roller having at least part of the surface layer of oil-absorbing rubber. When a roller provided with oil-absorbing rubber in at least a part of its surface layer is used as the absorbing roller 14, the solvent contained in the oil-based ink can be efficiently absorbed from the recording medium P.

  Further, as the absorbing roller 14, for example, it is preferable to use a roller provided with at least a part of the surface layer of silicone rubber. If a roller having silicone rubber at least part of the surface layer is used as the absorbing roller 14, the silicone rubber has a high releasability from the pigment, so that the solvent can be efficiently used without absorbing the pigment from the recording medium P. Can be absorbed.

  When water-based ink is used as the second solvent, it is preferable to use, as the absorbing roller 14, for example, a roller provided with a water-absorbing gel or the like in at least a part of the surface layer. If a roller provided with water-absorbing gel or the like at least in part of the surface layer is used as the absorbing roller 14, the solvent contained in the aqueous ink can be efficiently absorbed from the recording medium P.

  Further, the absorbing roller 14 may be a roller provided with a porous material such as a porous film in at least a part of the surface layer. In particular, when an alkane is used as the first solvent S and a fatty acid ester is used as the second solvent, a porous polypropylene film (pore diameter: 0.2 to 0.5 μm) should be used as the porous material. preferable. When a porous polypropylene film (pore size 0.2 to 0.5 μm) is used as the porous material, the solvent (liquid content) is absorbed at a high speed, and the solid content is highly releasable. The liquid component can be efficiently absorbed without doing so.

  The conveyance roller 15 rotates counterclockwise, for example, by rotating counterclockwise.

  The conveyance belt 16 conveys the recording medium P from the right side to the left side in the drawing by rotating, for example, counterclockwise according to the rotation of the conveyance roller 15.

  In the image forming apparatus according to the first embodiment, as described above, the mode in which the solvent on the recording medium P is absorbed by the absorption roller 14 has been described. However, the present invention is not limited in this respect. Any absorbing means that can absorb the solvent on the recording medium P may be used. As the absorbing means, for example, an absorbing blade can be used in addition to the absorbing roller 14 described above.

  In the image forming apparatus according to the first embodiment, the form in which the recording medium P is conveyed by the conveyance roller 15 and the conveyance belt 16 has been described. However, the present invention is not limited in this respect, and the recording medium is not limited thereto. Any conveying means capable of conveying P may be used. Examples of the conveying unit include the conveying roller 15 and the conveying belt 16 described above, and the conveying roller 15 that directly conveys the recording medium P without using the conveying belt 16. Further, when the transport roller 15 and the transport belt 16 are used as the transport means, a tension roller that applies tension to the transport belt 16 may be provided.

  Next, an image forming method in the image forming apparatus according to the first embodiment will be described with reference to FIG.

  First, the transport roller 15 and the transport belt 16 are rotated to transport the recording medium P onto the transport belt 16 (transport process).

  Subsequently, the application roller 11 is rotated to apply the first solvent S to the recording medium P conveyed on the conveyance belt 16 (application process).

  Subsequently, the inkjet ink I is ejected from the inkjet head 13, and the inkjet ink I is adhered to the first solvent S applied to the recording medium P (ejection process). At this time, the inkjet ink I includes a second solvent, and a resin and a coloring material dissolved in the second solvent. The first solvent S can precipitate the resin when the inkjet ink I is dropped. The second solvent can be miscible with the first solvent S.

  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. It becomes a solvent. At this 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. That is, the speed at which the second solvent diffuses into the first solvent S is larger than the speed at which the resin and the coloring material diffuse into the first solvent S.

  For this reason, before the resin and the color material diffuse into the first solvent S, the second solvent diffuses into the first solvent S, and the viscosity is in the vicinity of the contact surface between the inkjet ink I and the first solvent S. A region with increased is formed. And the area | region where the viscosity increased suppresses the spreading | diffusion to the 1st solvent S of resin and a coloring material.

Note that the greater the rate at which the second solvent diffuses into the first solvent S (hereinafter referred to as “diffusion rate” or “diffusion coefficient”), the more the resin and Diffusion of the color material into the first solvent S can be suppressed. For this reason, 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.

  Subsequently, the absorbing roller 14 is rotated to mix the solvent on the recording medium P, that is, at least one of the first solvent S applied to the recording medium P and the second solvent discharged to the recording medium P. Is absorbed (absorption process). Thereby, excess solvent can be removed from the recording medium P. As a result, the viscosity of the inkjet ink I on the recording medium P increases, and the fixability of the inkjet ink I to the recording medium P can be improved. Further, since a drying step for forcibly drying the solvent is not necessary, consumption of heat energy and the like for drying the solvent can be reduced.

  Subsequently, the recording medium P is further transported by the transport belt 16, and the recording medium P on which an image is formed is discharged from the image forming apparatus by a transport member (not shown) such as a paper discharge roller (discharge process). At this time, the ink on the recording medium P is sufficiently fixed in the absorption process, and therefore does not adhere to the conveyance member. That is, it is possible to prevent the inkjet ink I from adhering to a conveying member, such as a paper discharge roller, in the discharge step after image formation.

  Next, materials that can be suitably used for the image forming apparatus according to the first embodiment will be described.

  The ink-jet ink I only needs to contain a second solvent, a resin and a colorant that are soluble in the second solvent, and for example, an oil-based ink, a water-based ink, or the like can be used.

  Although it does not specifically limit as a viscosity of the inkjet ink I, For example, it adjusts so that it may become 1-20 mPa * s.

  Although it does not specifically limit as a weight average molecular weight of resin, For example, it is preferable to use the material of 2000-50000. When the weight average molecular weight of the resin is less than 2000, even if the content of the second solvent in the inkjet ink I is lowered, the viscosity may be difficult to increase. Moreover, when the weight average molecular weight of resin exceeds 50000, the viscosity of the inkjet ink I may become high too much.

  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, alkyd resin, and the like.

  The second solvent for the oil-based ink is not particularly limited as long as it can be mixed with the first solvent S. For example, dimethyl succinate, diethyl succinate, dibutyl adipate, isobutyl adipate, sebacic acid Examples thereof include dibasic acid esters such as dibutyl, and fatty acid esters such as ethyl laurate, isopropyl myristate, and butyl palmitate.

  The coloring material for the oil-based ink may be either an oil-soluble dye or a pigment, but is preferably a pigment because it is difficult to diffuse into the first solvent S.

  Examples of the pigment include, but are not limited to, carbon black, phthalocyanine blue, monoazo yellow, disazo yellow, benzimidazole yellow, anthraquinone yellow, polyazo yellow, monoazo red, brilliant carmine 6B, anthraquinone red, dimethylquinacridone, and the like. Is mentioned.

  When a pigment is used as the color material for the oil-based ink, 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 alkylammonium type polymer dispersants, block copolymer type polymer dispersants, and phosphate ester salt dispersants.

  The first solvent S for oil-based ink is not particularly limited as long as it does not dissolve the resin for oil-based ink and can be mixed with the second solvent for oil-based ink. For example, tridecane, tetradecane, High-boiling paraffinic hydrocarbons that are liquid at room temperature such as pentadecane, hexadecane, and heptadecane, high-boiling olefinic hydrocarbons such as pentadecene, hexadecene, and heptadecene, silicone oils such as dimethyl silicone oil, and fatty acid ester-modified silicone oil, etc. Two or more of these may be used in combination.

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

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

  As the coloring material and pigment dispersant for water-based ink, the same materials as the coloring material and pigment dispersant for oil-based ink can be used.

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

  As described above, according to the image forming method in the image forming apparatus according to the first embodiment, the coating step of applying the first solvent S to the recording medium P, the second solvent, and the second solvent. A discharge step of discharging an inkjet ink I containing a resin and a color material dissolved in the ink and adhering to the first solvent S applied to the recording medium P; and a first solvent S on the recording medium P and And an absorption step for absorbing at least one of the second solvents. The first solvent S can cause the resin to precipitate when the inkjet ink I is dropped, and the second solvent can be mixed with the first solvent S. For this reason, it is possible to improve the fixability of the image on the recording medium P.

[Second Embodiment]
Next, an image forming apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram illustrating a schematic configuration of an image forming apparatus according to the second embodiment.

  The image forming apparatus according to the second embodiment includes a sponge 12, an inkjet head 13, an absorption roller 14, a transport roller 15, an intermediate transfer body 21, and an intermediate transfer roller 22.

  The sponge 12 is impregnated with the first solvent S. The sponge 12 is provided so as to be in contact with the intermediate transfer member 21 and supplies the first solvent S to the intermediate transfer member 21. The width of the sponge 12 is not particularly limited, but is designed to be substantially the same as the width of the recording medium P, for example.

  The inkjet head 13 discharges the inkjet ink I according to the image signal, and causes the inkjet ink I to adhere to the first solvent S applied to the intermediate transfer body 21. The type of the inkjet head 13 is not particularly limited, but for example, a shuttle type head or a line type head can be used. An ink container (not shown) containing the inkjet ink I is connected to the inkjet head 13 via a tube (not shown) and a pump (not shown).

  The absorbing roller 14 is provided on the front side (left side in the figure) in the conveyance direction of the recording medium P with respect to the intermediate transfer roller 22. As the absorption roller 14, the same thing as 1st Embodiment can be used.

  The conveyance roller 15 is provided below the intermediate transfer roller 22 and conveys the recording medium P from the right side to the left side in the figure by rotating, for example, counterclockwise.

  The intermediate transfer member 21 is formed on the surface of the intermediate transfer roller 22.

  The intermediate transfer roller 22 is provided on the transport roller 15 and rotates, for example, clockwise so as to pressurize the inkjet ink I discharged onto the intermediate transfer member 21 formed on the surface while recording medium P. Transcript to. As the recording medium P, the same one as in the first embodiment can be used.

  Next, an image forming method in the image forming apparatus according to the second embodiment will be described with reference to FIG.

  First, the transport roller 15 is rotated to transport the recording medium P onto the transport roller 15 (transport process).

  Subsequently, the intermediate transfer roller 22 is rotated, and the first solvent S is applied to the intermediate transfer body 21 by the sponge 12 (application process).

  Subsequently, the inkjet ink I is ejected from the inkjet head 13, and the inkjet ink I is adhered to the first solvent S applied to the intermediate transfer body 21 (ejection process). At this time, the inkjet ink I includes a second solvent, and a resin and a coloring material dissolved in the second solvent. Further, the first solvent S can cause the resin to precipitate when the inkjet ink I is dropped. The second solvent can be mixed with the first solvent S.

  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. It becomes a solvent. At this 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. That is, the speed at which the second solvent diffuses into the first solvent S is larger than the speed at which the resin and the coloring material diffuse into the first solvent S.

  For this reason, before the resin and the color material diffuse into the first solvent S, the second solvent diffuses into the first solvent S, and the viscosity is in the vicinity of the contact surface between the inkjet ink I and the first solvent S. A region with increased is formed. And the area | region where the viscosity increased suppresses the spreading | diffusion to the 1st solvent S of resin and a coloring material.

  Subsequently, the ink-jet ink I having increased viscosity attached to the first solvent S is transferred to the recording medium P (transfer process). At this time, the ink-jet ink I having increased viscosity is easily transferred to the recording medium P because the solvent mixed with the intermediate transfer body 21 serves as a shielding layer.

  In the second embodiment, after the ejection step, the ink-jet ink I is thickened on the intermediate transfer body 21, and then the ink-jet ink I thickened on the recording medium P is transferred. At this time, since the first solvent S functions as a release layer, the amount of excess solvent on the recording medium P is smaller than that in the image forming method according to the first embodiment. For this reason, the fixability of the image onto the recording medium P can be particularly improved.

  Subsequently, the absorbing roller 14 is rotated to mix the solvent on the recording medium P, that is, at least one of the first solvent S applied to the recording medium P and the second solvent discharged to the recording medium P. Is absorbed (absorption process). Thereby, excess solvent can be removed from the recording medium P. As a result, the viscosity of the ink-jet ink I on the recording medium P increases, and the fixability of the ink-jet ink I (image) on the recording medium P can be improved. Further, since a drying step for forcibly drying the solvent is not necessary, consumption of heat energy and the like for drying the solvent can be reduced.

  Subsequently, the recording medium P is further transported by the transport belt 16, and the recording medium P on which an image is formed is discharged from the image forming apparatus by a transport member (not shown) such as a paper discharge roller (discharge process). At this time, the ink-jet ink I on the recording medium P is sufficiently fixed in the absorption process, and therefore does not adhere to the conveyance member. That is, it is possible to prevent the inkjet ink I from adhering to a conveying member, such as a paper discharge roller, in the discharge step after image formation.

  Next, materials that can be suitably used for the image forming apparatus according to the second embodiment will be described.

  As materials for the inkjet ink I and the first solvent S, the same materials as in the first embodiment can be used.

  The material of the intermediate transfer member 21 is not particularly limited as long as the wettability with respect to the first solvent S is good. For example, an elastic material such as silicone rubber, NBR rubber, chloroprene rubber, urethane rubber, and fluorine rubber, polyethylene terephthalate Examples thereof include thermoplastic resins such as (PET), heat resistant resins such as polyimide, polyimide amide, and polyether ketone, and metal materials such as nickel, aluminum, iron, and stainless steel.

  In particular, when the material of the intermediate transfer member 21 is used as an endless belt, a thermoplastic resin sheet using a thermoplastic resin, a heat resistant resin sheet using a heat resistant resin, and a metal material using stainless steel is stainless steel. Examples thereof include a sheet and a nickel sheet using nickel.

  Moreover, when using as an endless belt, it is preferable to give a fixed tension with a tension roller or the like. The tension roller is not particularly limited as long as the belt can be fed with a certain tension, but may be formed of a core material and a surface material, for example. The material of the core member of the tension roller is preferably a metal such as aluminum, iron or stainless steel, an alloy of these metals, or a material such as ceramics.

  If necessary, a surface material may be provided on the intermediate transfer member 21 to improve the wettability with the first solvent S and the releasability of the inkjet ink I. The surface material is not particularly limited. For example, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer. (ETFE), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-hexafluoropropylene polymer (FEP), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), etc. Can be mentioned.

  As described above, according to the image forming method in the image forming apparatus according to the second embodiment, the application step of applying the first solvent S to the intermediate transfer member 21, the second solvent, and the second solvent An ejection step in which an inkjet ink I containing a resin and a color material dissolved in a solvent is ejected and adhered to the first solvent S applied to the intermediate transfer body 21; and an inkjet adhered to the first solvent S A transfer step of transferring the ink I to the recording medium P; and an absorption step of absorbing at least one of the first solvent S and the second solvent on the recording medium P. The first solvent S can cause the resin to precipitate when the inkjet ink I is dropped, and the second solvent can be mixed with the first solvent S. For this reason, it is possible to improve the fixability of the image on the recording medium P.

  In particular, according to the image forming method in the image forming apparatus according to the second embodiment, after the ink jet ink I is thickened on the intermediate transfer member 21, the thickened ink jet ink I is transferred to the recording medium P. At this time, since the first solvent S functions as a release layer, the amount of excess solvent on the recording medium P is smaller than that in the image forming method according to the first embodiment. Further, excess solvent on the recording medium P can be removed in the absorption process. For this reason, the fixability of the image onto the recording medium P can be particularly improved.

[Third Embodiment]
Next, an image forming apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram illustrating a schematic configuration of an image forming apparatus according to the third embodiment.

  The image forming apparatus according to the third embodiment is different from the image forming apparatus according to the first embodiment in that the application unit that applies the first solvent S is the application head 31.

  The image forming apparatus according to the third embodiment has the same configuration as that of the first embodiment except for the above differences. For this reason, in the following description, it demonstrates focusing on the point which is different from 1st Embodiment.

  The application head 31 applies the first solvent S to the recording medium P by discharging the first solvent S in accordance with the image signal. Specifically, the application head 31 causes the first solvent S to be ejected in accordance with the image signal so that the region where the first solvent S is applied is substantially the same as the region where the inkjet ink I is adhered, The first solvent S is applied to the recording medium P. For this reason, the area | region which apply | coats the 1st solvent S can be made small, and the quantity of the excess solvent supplied on the recording medium P can be reduced.

  As described above, according to the image forming method in the image forming apparatus according to the third embodiment, the fixability of the image onto the recording medium P is the same as the image forming method in the image forming apparatus according to the first embodiment. Can be improved.

  In particular, according to the image forming method in the image forming apparatus according to the third embodiment, the first solvent S is ejected so that the region where the first solvent S is applied is substantially the same as the region where the inkjet ink I is adhered. Therefore, the area where the first solvent S is applied can be reduced. For this reason, the amount of excess solvent supplied onto the recording medium P can be reduced. As a result, the fixability of the image on the recording medium P can be particularly improved.

[Fourth Embodiment]
Next, an image forming apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram illustrating a schematic configuration of an image forming apparatus according to the fourth embodiment.

  The image forming apparatus according to the fourth embodiment is different from the image forming apparatus according to the second embodiment in that the application unit that applies the first solvent S is the application head 31.

  The image forming apparatus according to the fourth embodiment has the same configuration as that of the second embodiment except for the above differences. For this reason, in the following description, it demonstrates focusing on the point which is different from 2nd Embodiment.

  The coating head 31 discharges the first solvent S according to the image signal, and applies the first solvent S to the intermediate transfer body 21. Specifically, the application head 31 causes the first solvent S to be ejected in accordance with the image signal so that the region where the first solvent S is applied is substantially the same as the region where the inkjet ink I is adhered, The first solvent S is applied to the intermediate transfer member 21. For this reason, the area | region which apply | coats the 1st solvent S can be made small, and the quantity of the excess solvent supplied to the intermediate transfer body 21 can be reduced.

  As described above, according to the image forming method in the image forming apparatus according to the fourth embodiment, the fixability of the image to the recording medium P is the same as the image forming method in the image forming apparatus according to the second embodiment. Can be improved.

  In particular, according to the image forming method in the image forming apparatus according to the fourth embodiment, the first solvent S is discharged so that the region where the first solvent S is applied is substantially the same as the region where the inkjet ink I is adhered. Therefore, the area where the first solvent S is applied can be reduced. For this reason, the amount of excess solvent supplied to the intermediate transfer member 21 can be reduced. As a result, the fixability of the image on the recording medium P can be particularly improved.

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

[Example 1]
While stirring with a stirrer, 10 parts of low molecular weight polyester Byron 220 (manufactured by Toyobo Co., Ltd.) was dissolved in 80 parts of vinylizer 40 (diisobutyl adipate) (manufactured by Kao Corporation), and then the pigment dispersant DISPERBYK-2155 ( 5 parts) (manufactured by Big Chemie Japan) was dissolved. Next, the obtained solution, 5 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 3 hours 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.

  Next, an image was formed using the image forming apparatus according to the first embodiment.

  At this time, a pulse injector PIJ-15NSET (manufactured by Cluster Technology) was used as the inkjet head 13. As the first solvent S, Exepearl iPM (isopropyl myristate) (manufactured by Kao Corporation) was used. Further, as the sponge 12, a sponge (made by Toyo Polymer Co., Ltd.) containing the first solvent S was used. As the recording medium P, coated paper OK Super Art (manufactured by Oji Paper Co., Ltd.) was used.

In addition, the inkjet head 13 was arranged so that the time from application of the first solvent S to the recording medium P until adhesion of the inkjet ink I to the first solvent S was 0.5 seconds. Further, after applying the first solvent S so that the coating amount on the recording medium P was 0.16 mg / cm ² , about 8 pL of the inkjet ink I was adhered so as to be 0.16 mg / cm ² . .

  Moreover, the speed | rate which forms an inkjet image was 500 mm / s.

  Further, a silicone rubber roller as the absorbing roller 14 was arranged so that the time from when the inkjet ink I adhered to the first solvent S until the recording medium P was brought into contact with the absorbing roller 14 was 1.0 second.

Next, after the recording medium P comes into contact with the silicone rubber roller, the PPC paper Mypaper (manufactured by Ricoh) (hereinafter referred to as “PPC paper”) is pressed against the image forming area of the recording medium P, and the inkjet ink adhered to the PPC paper. The amount of I was evaluated according to the following criteria. Hereinafter, this evaluation is referred to as fixability evaluation.
Evaluation criteria:
(Double-circle): It is the adhesion amount which cannot be recognized with the naked eye.
○: Almost no adhesion
(Triangle | delta): There exists some adhesion.
X: Significant adhesion

[Comparative Example 1]
After the image formation, an image was formed and the fixability was evaluated in the same manner as in Example 1 except that the recording medium P was not brought into contact with the silicone rubber roller.

[Example 2]
An image was formed in the same manner as in Example 1 except that the image forming apparatus according to the second embodiment was used.

  At this time, a pulse injector PIJ-15NSET (manufactured by Cluster Technology) was used as the inkjet head 13. As the first solvent S, Exepearl iPM (isopropyl myristate) (manufactured by Kao Corporation) was used. Further, as the sponge 12, a sponge (made by Toyo Polymer Co., Ltd.) containing the first solvent S was used. Further, as the intermediate transfer member 21, a roller formed by forming a silicone rubber layer as the intermediate transfer member 21 on the surface of the intermediate transfer roller 22 made of SUS material, which can be rotated at a predetermined speed by an actuator, was used. As the recording medium P, coated paper OK Super Art (manufactured by Oji Paper Co., Ltd.) was used.

Further, the inkjet head 13 was arranged so that the time from application of the first solvent S to the intermediate transfer member 21 until adhesion of the inkjet ink I to the first solvent S was 0.5 seconds. In addition, after applying the first solvent S so that the application amount to the intermediate transfer member 21 is 0.16 mg / cm ² , about 8 pL of the inkjet ink I is adhered so as to be 0.16 mg / cm ^2. It was.

  Moreover, the speed | rate which forms an inkjet image was 500 mm / s.

  Further, a silicone rubber roller as the absorbing roller 14 was disposed so that the absorbing roller 14 would come into contact with the recording medium P 1.0 seconds after the inkjet ink I adhered to the first solvent S.

  Next, in the same manner as in Example 1, the fixability of the formed image was evaluated.

[Comparative Example 2]
After the image formation, an image was formed and the fixability was evaluated in the same manner as in Example 2 except that the recording medium P was not brought into contact with the silicone rubber roller.

[Example 3]
Except for using the image forming apparatus according to the third embodiment, an image was formed and the fixability was evaluated in the same manner as in Example 1.

  That is, as a means for applying the first solvent S to the recording medium P, the area where the first solvent S is applied is substantially the same as the area where the ink-jet ink I is adhered using the application head 31. Except for this point, an image was formed and the fixability was evaluated in the same manner as in Example 1.

[Comparative Example 3]
An image was formed and the fixability was evaluated in the same manner as in Example 3 except that the recording medium P was not brought into contact with the silicone rubber roller after the image formation.

[Example 4]
An image was formed and the fixability was evaluated in the same manner as in Example 2 except that the image forming apparatus according to the fourth embodiment was used.

  That is, as a means for applying the first solvent S to the intermediate transfer member 21, the area where the first solvent S is applied using the application head 31 is substantially the same as the area where the inkjet ink I is adhered. Except for these points, an image was formed and the fixability was evaluated in the same manner as in Example 2.

[Comparative Example 4]
After the image formation, an image was formed in the same manner as in Example 4 except that the recording medium P was not brought into contact with the silicone rubber roller, and the fixability was evaluated.

  Table 1 shows the results of evaluation of fixability of the images formed in Examples 1 to 4 and Comparative Examples 1 to 4 described above.

  From the results in Table 1, the following can be understood.

  In Examples 1 and 3 in which the recording medium P is brought into contact with the silicone rubber roller as the absorbing roller 14, the inkjet ink I is almost adhered to the PPC paper when the PPC paper is pressed against the image forming area of the recording medium P. It wasn't.

  Further, in Examples 2 and 4 in which the recording medium P is brought into contact with the silicone rubber roller as the absorbing roller 14, the inkjet ink I attached to the PPC paper when the PPC paper is pressed against the image forming area of the recording medium P is: The amount of adhesion was invisible to the naked eye.

  On the other hand, in Comparative Examples 1 and 3 in which the recording medium P was not brought into contact with the silicone rubber roller as the absorbing roller 14, the PPC paper when the PPC paper was pressed against the image forming area of the recording medium P was inkjet. Ink I was remarkably adhered.

  In Comparative Examples 2 and 4 in which the recording medium P was not brought into contact with the silicone rubber roller as the absorbing roller 14, the inkjet ink I was applied to the PPC paper when the PPC paper was pressed against the image forming area of the recording medium P. A little adhered.

  As described above, it was confirmed that good fixability was exhibited by bringing the recording medium P into contact with the absorbing roller 14.

  The image forming apparatus and the image forming method have been described above by the embodiments and examples. However, the present invention is not limited to the above embodiments and examples, and various modifications and improvements can be made within the scope of the present invention. It is.

11 Application roller 12 Sponge 13 Ink jet head 14 Absorption roller 21 Intermediate transfer body 22 Intermediate transfer roller 31 Application head I Ink jet ink P Recording medium S First solvent

JP 2011-143705 A

Claims (7)

An application step of applying the first solvent to the recording medium conveyed by the conveying means ;
A discharge step of discharging an ink-jet ink containing a second solvent and a resin and a colorant dissolved in the second solvent, and attaching the ink-jet ink to the first solvent applied to the recording medium;
An absorption step for absorbing at least one solvent of the first solvent and the second solvent on the recording medium,
A discharge step of discharging the recording medium by the conveying means after the absorption step ;
The first solvent can deposit the resin when the inkjet ink is dropped.
The second solvent is miscible with the first solvent;
Image forming method. An application step of applying a first solvent to the intermediate transfer member;
A discharge step of discharging an ink-jet ink containing a second solvent and a resin and a colorant dissolved in the second solvent, and attaching the ink-jet ink to the first solvent applied to the intermediate transfer body;
A transfer step of transferring the inkjet ink attached to the first solvent to a recording medium;
An absorption step for absorbing at least one of the first solvent and the second solvent on the recording medium,
The first solvent can deposit the resin when the inkjet ink is dropped.
The second solvent is miscible with the first solvent;
Image forming method. The absorbing step absorbs at least one of the first solvent and the second solvent on the recording medium by an absorbing means including a roller.
The image forming method according to claim 1. The roller includes silicone rubber in at least a part of its surface layer.
The image forming method according to claim 3. The region to which the first solvent is applied is substantially the same as the region to which the inkjet ink is attached.
The image forming method according to claim 1. Application means for applying a first solvent to the recording medium;
A discharge means for discharging an ink-jet ink containing a second solvent and a resin and a colorant dissolved in the second solvent, and attaching the ink-jet ink to the first solvent applied to the recording medium;
And absorbing means for absorbing at least one solvent of the first solvent and the second solvent on the recording medium,
Conveying means for discharging the recording medium in which the solvent is absorbed by the absorbing means ;
The first solvent can deposit the resin when the inkjet ink is dropped.
The second solvent is miscible with the first solvent;
Image forming apparatus. An intermediate transfer member;
Application means for applying a first solvent to the intermediate transfer member;
A discharge means for discharging an ink-jet ink containing a second solvent and a resin and a colorant dissolved in the second solvent, and attaching the ink-jet ink to the first solvent applied to the intermediate transfer body;
Transfer means for transferring the inkjet ink attached to the first solvent to a recording medium;
Absorbing means for absorbing at least one of the first solvent and the second solvent on the recording medium,
The first solvent can deposit the resin when the inkjet ink is dropped.
The second solvent is miscible with the first solvent;
Image forming apparatus.

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