JP4096422B2 - Inkjet recording apparatus and image forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an inkjet recording apparatus, an image forming method, and an ink composition capable of obtaining a high-quality image on a recording material, and more specifically, recording is performed on plain paper at high speed without bleeding. Inkjet recording apparatus capable ofAnd image forming methodAbout.
[0002]
[Prior art]
  Conventionally, among various printing methods, an ink jet recording method using water-based ink is widely used in small and low-cost printers because of its simple process. In particular, it is also known that when a so-called special coated paper having an ink receiving layer coated on the surface is used as a recording member, a particularly high-quality output can be obtained. On the other hand, when so-called plain paper is used as the recording material, there is a problem that the image permeates or becomes thin because the ink penetrates along the fiber of the paper. Furthermore, it is difficult to increase the speed due to the slow evaporation of water in the water-based ink, or a phenomenon called “show-through” in which the ink penetrates to the back side of the printing surface of plain paper, and outputs a high-quality image. Was difficult.
[0003]
  On the other hand, there is an ink jet system that uses ink which is not water-based ink but is called hot melt ink or solid ink, which is solid at normal temperature and suddenly decreases in viscosity when heated to 80 to 150 ° C. According to this method, the ink that is heated and discharged in a low-viscosity liquid state adheres to the surface of the recording member and is rapidly cooled and fixed. Even if the recording member is plain paper, the ink is solidified faster than the ink permeates along the fiber, so that the image does not bleed and the time required for fixing is short, so that a high-speed printer can be realized.
[0004]
[Problems to be solved by the invention]
  However, in the ink jet system using such hot melt ink, a heating mechanism for raising the temperature of the ink to near the melting point is essential, and therefore, it is difficult to downsize the apparatus as compared with the water-based ink jet system, and power consumption is reduced. There was a problem that there were many.
[0005]
  The present invention has been devised to solve the above problems, and can record high-definition and clear images even on plain paper that has not been specially processed, and the apparatus is small. Inkjet printer with low power consumptionAnd image forming methodIs to provide.
[0006]
[Means for Solving the Problems]
  The first aspect of the present invention is an ink jet recording apparatus that records an image on a recording member (1) by ejecting ink for forming an image. The first recording material includes a radical polymerizable substance and a photopolymerization initiator. A first discharge means (11-14) for discharging the ink composition (2) toward the recording member (1), and a first ink composition (2) discharged by the first discharge means (3) ) Containing at least one of an amine-based material and a mercaptan-based material that acts on the reaction between the radical polymerizable substance and the photopolymerization initiator to promote the polymerization reaction and improve the curing sensitivity. And a second ejecting means (15) for ejecting the second ink composition (4), and the first ink composition (2) and the second ink composition (2) on the recording member (1). 4) is mixed and cured Ri was such that at least a portion of the image is formed.
[0007]
  According to this invention, the reaction between the first ink composition (2) containing the radical polymerizable substance and the photopolymerization initiator on the recording member (1), and the radical polymerizable substance and the photopolymerization initiator is performed. The image is obtained by mixing and curing the second ink composition (4) containing at least one of an amine-based material and a mercaptan-based material to act to promote these polymerization reactions and improve curing sensitivity. Therefore, it is possible to record a high-definition and clear image even on plain paper that has not been subjected to special processing, and the size of the apparatus can be reduced and power consumption can be reduced.
[0008]
  The invention according to claim 2 is the ink jet recording apparatus according to claim 1, wherein the mixture (6) of the first ink composition (2) and the second ink composition (4) is cured by radical polymerization reaction. To do.
[0009]
  According to the present invention, since the radical polymerization reaction is used, the mixture (6) can be cured in a short time.
[0010]
  According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect, the first ink composition (2) and the second ink composition ( The light irradiation means (8) which irradiates light (7) toward the mixture (6) of 4), and hardens the mixture (6) is provided.
[0011]
  According to the present invention, the curing time and the curing start timing of the mixture (6) can be controlled. For example, the level of the mixture (6) and the degree of penetration into the recording member (1) are optimized. To improve the image quality.
[0012]
  According to a fourth aspect of the present invention, in the image forming method for forming an image on the recording member (1) by discharging ink, the first ink composition containing a radical polymerizable substance and a photopolymerization initiator. A first discharge step of discharging (2) toward the recording member (1), and the radical polymerizable substance toward the first ink composition (2) discharged in the first discharge step; A second ink composition (4) containing at least one of an amine-based material and a mercaptan-based material that acts on the reaction with the photopolymerization initiator to promote these polymerization reactions and improve curing sensitivity. A second discharge step for discharging, and the first ink composition (2) and the second ink composition (4) are mixed and cured on the recording member (1), thereby at least forming an image. A part was formed.
[0013]
  According to this invention, the reaction between the first ink composition (2) containing the radical polymerizable substance and the photopolymerization initiator on the recording member (1), and the radical polymerizable substance and the photopolymerization initiator is performed. The image is obtained by mixing and curing the second ink composition (4) containing at least one of an amine-based material and a mercaptan-based material to act to promote these polymerization reactions and improve curing sensitivity. Therefore, high-definition and clear images can be recorded even on plain paper that has not been specially processed, and the size of the device for forming images can be reduced and power consumption can be reduced. be able to.
[0014]
  The invention according to claim 5 is the image forming method according to claim 4, wherein the mixture (6) of the first ink composition (2) and the second ink composition (4) is cured by radical polymerization reaction. To do.
[0015]
  According to the present invention, since the radical polymerization reaction is used, the mixture (6) can be cured in a short time.
[0016]
  According to a sixth aspect of the present invention, in the image forming method according to the fourth or fifth aspect, the first ink composition ejected onto the recording member (1) by the first ejection step and the second ejection step. It is characterized by comprising a light irradiation step of irradiating light (7) toward the mixture (6) of the product (2) and the second ink composition (4) to cure the mixture (6).
[0017]
  According to the present invention, the curing time and the curing start timing of the mixture (6) can be controlled. For example, the level of the mixture (6) and the degree of penetration into the recording member (1) are optimized. To improve the image quality.
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present book will be described with reference to FIGS.EmbodimentInkjet recording apparatus, image forming method, and ink compositionTo thingsexplain about.
[0025]
  1 to 4 show an embodiment in which an ink jet recording apparatus according to the present invention is applied to a printer having four color ink jet heads. 1 is a perspective view showing the vicinity of the ink jet head, FIG. 2 is a view showing an arrangement inside the ink jet head viewed from above in FIG. 1, FIG. 3 is an enlarged view showing the vicinity of the ink jet head viewed from above in FIG. FIG. 2 is a cross-sectional view of the vicinity of an inkjet head.
[0026]
  As shown in FIGS. 1 to 3, the ink jet recording apparatus according to the present embodiment includes a black unit 11 that discharges black ink, a cyan unit 12 that discharges cyan ink, a magenta unit 13 that discharges magenta ink, and yellow ink. A print head 10 on which a yellow unit 14 for discharging and a processing liquid unit 15 for discharging a processing liquid are mounted is provided. As shown in FIG. 3, the black unit 11 has a black ink cartridge 11a and a black ink head 11b, the cyan unit 12 has a cyan ink cartridge 12a and a cyan ink head 12b, and the magenta unit 13 has a magenta ink cartridge 13a. The yellow unit 14 includes a yellow ink cartridge 14a and a yellow ink head 14b, and the processing liquid unit 15 includes a processing liquid cartridge 15a and a processing liquid head 15b.
[0027]
  As shown in FIGS. 1, 3 and 4, the print head 10 is slidably attached to the shuttle shaft 20. A print head feed wire 21 extending in the axial direction of the shuttle shaft 20 is attached to the print head 10, and the print head 10 can be reciprocated along the shuttle shaft 20 by driving the wire 21.
[0028]
  As shown in FIG. 1, a platen drum 25 whose axis is parallel to the shuttle shaft 20 is provided, and the recording paper 1 fed through the platen drum 25 faces the print head 10. As shown in FIG. 1, the print head 10 is connected to the control unit 23 via a connection line 24, and in response to a signal output from the control unit 23, ink or processing liquid is supplied from the heads 11b to 15b in a predetermined manner. It is discharged at the timing. The discharged ink or processing liquid adheres to the recording paper 1 on the platen drum 25. The ink ejection operation is the same as that of a normal ink jet printer, and detailed description thereof is omitted. For example, the pressure based on the air pump is applied to each unit 11 to 15 at a predetermined timing, thereby causing the internal ink to flow. Alternatively, a known technique for discharging the processing liquid can be used.
[0029]
  As shown in FIG. 4, an ink curing light irradiation device 8 including a lamp 81 and a reflector 82 is provided in the vicinity of the platen drum 25, and the ink is cured toward the recording paper 1 fed from the platen drum 25. The light 7 having a predetermined wavelength suitable for the above is irradiated.
[0030]
  5 shows a recording ink 2 that is one of black ink, cyan ink, magenta ink, or yellow ink on the recording paper 1 fed in the direction of the arrow P (in FIG. 5, yellow ink discharged from the yellow unit 14). The ink is illustrated) and the treatment liquid 4 is sequentially ejected to the same position of the recording paper 1 to be cured, and the cured ink 6A is composed of the recording ink 2 and the treatment liquid 4. The state after the mixture 6 is leveled and hardened is shown. In order to eject the recording ink 2 and the treatment liquid 4 to the same position on the recording paper 1, after the recording ink 2 is ejected, the print head 10 is shuttled by a predetermined amount while feeding of the recording paper 1 is stopped. The treatment liquid 4 may be discharged by moving along the axis 20.
[0031]
  The composition of the recording ink 2 and the treatment liquid 4 may be selected such that the chemical reaction proceeds and is cured only by mixing the two, and curing is performed by the light 7 from the light irradiation device 8. You may choose to start. As a matter of course, when the recording ink 2 and the treatment liquid 4 having the former composition are selected, the light irradiation device 8 can be omitted.
[0032]
  As described above, when the recording ink 2 and the treatment liquid 4 are mixed on the recording member 1 or when the light 7 is irradiated after the mixing, the curing reaction is started and the mixture 6 is cured, thereby the image. A part of is formed. Accordingly, the recording ink 2 and the treatment liquid 4 are sequentially ejected at a predetermined timing while the recording member 1 is fed, and the mixture 6 is cured, whereby a predetermined image having the cured ink 6A as a pixel can be formed. .
[0033]
  In the case where the light irradiation device 8 is provided, the curing time can be shortened by increasing the intensity of the light 7, so that an appropriate curing time according to the application can be obtained. Moreover, the timing of starting the curing of the mixture 6 can be freely adjusted by the timing of irradiating the light 7. Thus, by adjusting the curing time and the timing of starting curing, the level of the mixture 6 and the degree of the mixture 6 penetrating into the recording member 1 can be optimized to improve the image quality. Further, the hardness of the cured ink can be controlled by adjusting the amount of light irradiation.
[0034]
  Although FIG. 1 shows a case where the processing liquid 4 is discharged after the recording ink 2 is discharged, the recording ink may be discharged after discharging the processing liquid by reversing the discharge order. Although not shown in FIG. 1, a heating device may be provided for heating the mixture of the recording ink and the processing liquid to promote curing.
[0035]
  Next, the composition of the recording ink and the processing liquid will be described.
[0036]
  As the radically polymerizable substance of the recording ink, a substance containing an ethylenically unsaturated group is used, and in particular, a substance having an acryloyl group or a methacryloyl group is desirable from the viewpoint of polymerization rate. Acrylic acid and its salts, acrylic esters , Acrylamides, methacrylic acid and salts thereof, methacrylic acid esters, methacrylamides, and derivatives thereof. Of these, acrylic acid esters or methacrylic acid esters are particularly desirable.
[0037]
  Specific examples of acrylic esters include phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, methoxy polyethylene glycol acrylate, lauryl acrylate, butyl acrylate, cyclohexyl acrylate, ethyl hexyl acrylate, benzyl acrylate, furfuryl acrylate, ethoxyethyl acrylate , Tricyclodecanyloxy acrylate, nonylphenyloxyethyl acrylate, hexanediol acrylate, 1,3-dioxolane acrylate, polyethylene glycol diacrylate, hexanediol diacrylate, butanediol diacrylate, neopentyl glycol diacrylate, tricyclode Dimethylol diacrylate, tripropylene glycol diacrylate, bisphenol A diacrylate, trimethylol propane triacrylate, tetramethylol methane triacrylate, pentaerythritol triacrylate, tetramethylol methane tetraacrylate, dipentaerythritol hexaacrylate, caprolactone of dipentaerythritol Examples include adduct hexaacrylate, trimethylolpropane propylene oxide adduct triacrylate, polyoxyethylenated bisphenol A diacrylate, polyester acrylate, polyurethane acrylate, and the like.
[0038]
  Specific examples of methacrylic acid esters include butyl methacrylate, cyclohexyl methacrylate, ethyl hexyl methacrylate, methoxypolyethylene glycol methacrylate, methoxydiethylene glycol methacrylate, benzyl methacrylate, furfuryl methacrylate, ethoxyethyl methacrylate, hexanediol methacrylate, stearyl methacrylate, hexanediol dimethacrylate. 1,3-dioxolane methacrylate, butanediol dimethacrylate, neopentyl glycol dimethacrylate, bisphenol A dimethacrylate, pentaerythritol trimethacrylate, trimethylolpropane trimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythris Hexa methacrylate caprolactone adduct of tall, trimethylolpropane trimethacrylate, trimethacrylate propylene oxide adduct of trimethylolpropane, dimethacrylate of polyoxyethylenated bisphenol A, polyester methacrylate, polyurethane methacrylate. These unsaturated group-containing substances may be used alone or in combination of two or more. Further, in some cases, a cyclic organic compound may be contained in addition to the unsaturated group-containing substance.
[0039]
  As a color image forming substance of a recording ink, a pigment or a dye which is colored itself is used. In addition to commercially available materials, various documents (for example, “Dye Handbook” edited by Organic Synthetic Chemistry Association, published in 1970, “Latest” Known materials described in “Handbook of Pigments” edited by Japan Pigment Technical Association, published in 1977 can be used.
[0040]
  The color image forming substance is selected in consideration of compatibility with the polymerizable substance and dispersibility, and it is desirable to use a pigment when importance is attached to the light resistance of the image. Various solvents may be used to help dissolve the dye, and a pigment dispersant or the like may be used in combination to improve the dispersibility of the pigment.
[0041]
  In addition to the radical polymerizable substance and the color image forming substance, the recording ink may contain a photopolymerization initiator that initiates the polymerization of the radical polymerizable substance by light energy. By containing a photopolymerization initiator, the curability can be controlled by light irradiation, so it can be adjusted to any hardness by changing the amount of light, etc. It is also possible.
[0042]
  Specific examples of the photopolymerization initiator include aromatic carbonyl compounds, acetophenones, organic peroxides, diphenylhalonium salts, organic halides, 2,4,6-substituted-S-triazines, 2,4,5 -Triarylimidazole dimer, azo compound, dye borate complex, metal arene complex, titanocene compound and the like. Desirably, benzophenone, benzyl, xanthone, thioxanthone, anthraquinone, acetophenone, 2,2-dimethyl-2-morpholino-4'-methylthioacetophenone, benzoyl peroxide, 3,3 ', 4,4'-tetra (tertiarybutyl Benzophenone), diphenyliodonium bromide, diphenyliodonium chloride, carbon tetrachloride, carbon tetrabromide, 2,4,6-tristrichloromethyl-S-triazine, [(η5-2,4-cyclopentadien-1-yl) [ (1,2,3,4,5,6-η)-(1-methylethyl) benzene] iron (1+) hexafluorophosphate (1-)] and the like. Moreover, these photoinitiators may be individual or may mix 2 or more types.
[0043]
  When a photopolymerization initiator is contained, an appropriate amount of a stabilizer may be added to the recording ink in consideration of long-term storage.
[0044]
  The treatment liquid contains at least an amine-based substance, a mercaptan-based (thiol-based), or both. Of the amine-based materials, aromatic amines are desirable, and N, N-dialkylaniline-based materials are particularly desirable. Specific examples thereof include 4-cyano-N, N-dimethylaniline, 4-acetyl-N, N-dimethylaniline, 4-bromo-N, N-dimethylaniline, 4-methyl-N, N-dimethylaniline, 4-ethoxy-N, N-dimethylaniline, 4-amino-N, N-dimethylaniline, 3-hydroxy-N, N-dimethylaniline, N, N, N ′, N′-tetramethyl-1,4- Dianiline, 4-acetamido-N, N-dimethylaniline, 2.6-diethyl-N, N-dimethylaniline, 2,6-diisopropyl-N, N-dimethylaniline, N, N, 2,4,6-penta Examples thereof include methylaniline, pt-butyl-N, N-dimethylaniline and the like.
[0045]
  As the mercaptan-based substance, thioglycolic acid derivatives and mercaptopropionic acid derivatives are desirable. Specific examples thereof include thioglycolic acid, ammonium thioglycolate, monoethanolamine thioglycolate, sodium thioglycolate, methyl thioglycolate, octyl thioglycolate, methoxybutyl thioglycolate, butanediol bisthioglycolate, Ethylene glycol bisthioglycolate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthioglycolate, 3-mercaptopropionic acid, methyl mercaptopropionate, octyl mercaptopropionate, methoxybutyl mercaptopropionate, tridecyl mercaptopropionate, butane Diol bisthiopropionate, ethylene glycol bisthiopropionate, trimethylolpropane tristhiopropionate DOO, pentaerythritol tetrakis thiopropionate and the like.
[0046]
  The radically polymerizable substance starts to be polymerized by mixing the recording ink and the processing liquid or by irradiating light after mixing. In general, since radical polymerization has a very high polymerization rate, the viscosity can be sufficiently increased (cured) within 1 second after mixing. The polymerization rate can be freely adjusted by the composition of the polymerizable substance, the photoinitiator, the treatment liquid and the ratio thereof.
[0047]
  When it contains a photopolymerization initiator, the polymerization reaction does not proceed at all until the light is irradiated, and the polymerization proceeds quickly at the same time as the light irradiation, or the polymerization proceeds slowly after mixing. It can also be said that the polymerization rate is rapidly increased by light irradiation.
[0048]
  Thus, by changing the composition of the recording ink and the treatment liquid, the polymerization rate can be freely selected according to the recording environment or application.
[0049]
  As the components of the recording ink and the treatment liquid, a photocurable composition as shown below can also be used. In this case, it is necessary to use the photopolymerization initiator and the dye or sensitivity sensitizer separately in the recording ink and the processing liquid. Furthermore, since the viscosity of the discharge liquid needs to be low to some extent in order to discharge the liquid from a small nozzle, it is necessary to adjust the viscosity of the photocurable composition.
[0050]
  Conventional photocurable compositions include ultraviolet curable compositions used in photoresists and compositions that are sensitive to visible light.
[0051]
  Polyamides described in Japanese Patent Publication No. 35-14719, Japanese Patent Publication No. 35-15513, Japanese Patent Publication No. 45-7330, Japanese Patent Publication No. 54-22229, etc. are used as photoresists. In addition, those having an azido group, a cinnamoyl group, and the like are known.
[0052]
  Examples of photocurable compositions that are sensitive to visible light include dye-amine complex systems (Japanese Patent Publication No. 44-20189), hexaarylbiimidazoles, radical generators and dye systems (Japanese Patent Publication No. 44-20189). Systems of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528, Japanese Patent Laid-Open No. 54-155292), systems of 3-keto-substituted coumarin compounds and active halogen compounds (Japanese Patent Laid-Open No. 58) No.-15503) and substituted triazine and merocyanine dye systems (Japanese Patent Laid-Open No. 54-15102).
[0053]
  Furthermore, a compound that uses silver halide as a trigger and accelerates the curing reaction by heat can also be used. In this case, it goes without saying that heating is required for the curing reaction (Japanese Patent Publication No. 550739).
[0054]
  A compound used as a two-component curable adhesive can also be used. However, in general, the adhesive has a very high viscosity, so that it is necessary to use a diluent to reduce the viscosity.
[0055]
  Examples of the diluent include water, an organic solvent such as alcohol, or a low-viscosity polymerizable substance that can be copolymerized with an adhesive. It is desirable to use a low-viscosity polymerizable substance because water has a drying problem and an organic solvent has a danger or toxicity problem. Furthermore, two-component curable adhesives often require at least several tens of minutes to cure, and therefore are difficult to use when it is necessary to cure the recording material immediately after ejecting ink (several seconds or less). It is.
[0056]
【Example】
  Example 1
  In Example 1, an example of a system in which the recording ink contains a photopolymerization initiator, the sensitivity is remarkably improved by mixing with a treatment liquid, and the viscosity is instantaneously increased (cured) by light irradiation will be described.
[0057]
  First, a yellow recording ink containing a yellow pigment was prepared.
[0058]
  3 parts by weight of an azo yellow pigment is dispersed in 100 parts by weight of a mixture of methoxydiethylene glycol methacrylate and trimethylolpropane trimethacrylate in a ratio of 3: 1 using a polymer polyurethane as a dispersant. To this, a photopolymerization initiator [(η 5 -2,4-cyclopentadien-1-yl) [(1,2,3,4,5,6-η)-(1-methylethyl) benzene] iron (1+) 2 parts by weight of hexafluorophosphate (1-)] and 0.1 part by weight of hydroquinone as a stabilizer were added and dissolved by heating at 100 ° C. for 10 minutes, followed by cooling to obtain a yellow recording ink.
[0059]
  The magenta, cyan and black recording inks were produced in the same manner as the yellow recording ink except that the pigments were different.
[0060]
  Next, a treatment liquid was prepared.
[0061]
  A treatment liquid was obtained by mixing 50 parts by weight of propylene carbonate, 20 parts by weight of N, N, 2,4,6-pentamethylaniline and 30 parts by weight of pentaerythritol tetrakisthiopropionate.
[0062]
  The ink jet recording apparatus using the recording ink and the treatment liquid thus produced is provided with an ultraviolet lamp corresponding to the light irradiation apparatus 8 of FIG. Using such an apparatus, after the yellow recording ink is ejected onto the paper, the processing liquid is ejected to the same location as the yellow recording ink. Then, the recording ink and the processing liquid are mixed on the paper. In Example 1, the polymerization reaction does not proceed only by mixing the recording ink and the treatment liquid, and the polymerization is started only when light energy is applied. By irradiating the ultraviolet lamp after mixing the recording ink and the treatment liquid, the polymerization reaction proceeds rapidly, the ink viscosity increases, and the ink is fixed on the paper. In this case, a significant improvement in sensitivity can be obtained by mixing the recording ink and the treatment liquid, so that it can be cured by short-time exposure. An image could be formed in the same manner when recording inks of other colors were used.
[0063]
[0064]
[0065]
[0066]
[0067]
[0068]
[0069]
【The invention's effect】
  According to the first aspect of the present invention, the first ink composition containing the radical polymerizable substance and the photopolymerization initiator on the recording member acts on the reaction between the radical polymerizable substance and the photopolymerization initiator. Since an image is formed by mixing and curing the second ink composition containing at least one of an amine-based material and a mercaptan-based material for promoting the polymerization reaction and improving the curing sensitivity. Further, it is possible to record a high-definition and clear image even on plain paper that has not been subjected to special processing, and the apparatus can be reduced in size and power consumption can be reduced.
[0070]
  According to invention of Claim 2, since a radical polymerization reaction is utilized, a mixture can be hardened in a short time.
[0071]
  According to the third aspect of the present invention, the curing time of the mixture and the timing of the curing start can be controlled. For example, the level of the mixture and the degree of penetration into the recording member are optimized to improve the image quality. Can be improved.
[0072]
  According to the fourth aspect of the present invention, the first ink composition containing the radical polymerizable substance and the photopolymerization initiator on the recording member acts on the reaction between the radical polymerizable substance and the photopolymerization initiator. Since an image is formed by mixing and curing the second ink composition containing at least one of an amine-based material and a mercaptan-based material for promoting the polymerization reaction and improving the curing sensitivity. Further, it is possible to record a high-definition and clear image even on plain paper that has not been subjected to special processing, and it is possible to reduce the size of an apparatus for forming an image and to reduce power consumption.
[0073]
  According to the fifth aspect of the invention, since the radical polymerization reaction is used, the mixture can be cured in a short time.
[0074]
  According to the invention described in claim 6, since the curing time of the mixture and the timing of the curing start can be controlled, for example, the image quality can be improved by optimizing the level of the mixture and the degree of penetration into the recording member. Can be improved.
[0075]
[0076]
[0077]
[Brief description of the drawings]
FIG. 1 is a perspective view showing the vicinity of an ink jet head in an ink jet recording apparatus according to an embodiment.
FIG. 2 is a diagram illustrating an arrangement inside the inkjet head as viewed from above in FIG.
FIG. 3 is an enlarged view showing the vicinity of the inkjet head viewed from above in FIG. 1;
FIG. 4 is a cross-sectional view of the vicinity of an inkjet head.
FIG. 5 is a diagram schematically illustrating how ink is fixed.
[Explanation of symbols]
  1 Recording member
  2 Recording ink
  3 Recording ink ejection part
  4 Treatment liquid
  5 Treatment liquid discharge part
  6 Mixture
  7 Light
  8 Light irradiation device

Claims (6)

In an ink jet recording apparatus that records an image on a recording member by discharging ink for image formation,
First discharge means for discharging a first ink composition containing a radical polymerizable substance and a photopolymerization initiator toward the recording member;
The first ink composition ejected by the first ejection means acts on the reaction between the radical polymerizable substance and the photopolymerization initiator to promote the polymerization reaction, thereby increasing the curing sensitivity. A second ejection means for ejecting a second ink composition containing at least one of an amine-based material and a mercaptan-based material for improvement,
Inkjet recording characterized in that at least part of the image is formed by mixing and curing the first ink composition and the second ink composition on the recording member. apparatus.   The inkjet recording apparatus according to claim 1, wherein the mixture of the first ink composition and the second ink composition is cured by a radical polymerization reaction.   And a light irradiation means for irradiating light toward the mixture of the first ink composition and the second ink composition discharged onto the recording member to cure the mixture. The ink jet recording apparatus according to claim 1. In an image forming method of forming an image on a recording member by discharging ink,
A first discharge step of discharging a first ink composition containing a radical polymerizable substance and a photopolymerization initiator toward the recording member;
The first ink composition ejected in the first ejection step acts on the reaction between the radical polymerizable substance and the photopolymerization initiator to promote the polymerization reaction, thereby improving the curing sensitivity. A second ejection step of ejecting a second ink composition containing at least one of an amine-based material and a mercaptan-based material for improvement,
Image formation characterized in that at least a part of the image is formed by mixing and curing the first ink composition and the second ink composition on the recording member. Method.   The image forming method according to claim 4, wherein the mixture of the first ink composition and the second ink composition is cured by a radical polymerization reaction.   Irradiating light toward the mixture of the first ink composition and the second ink composition ejected onto the recording member in the first ejection step and the second ejection step, The image forming method according to claim 4, further comprising a light irradiation step of curing the mixture.

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