JP4448155B2 - Image fixing method, method for producing recorded matter using the method, and image recording apparatus - Google Patents

Description

  The present invention relates to an image fixing method, a method for producing a recorded matter using the method, and an image recording apparatus, and more particularly to a technique for obtaining a recorded matter having high fastness of a recorded image.

  The fixing method of the image recorded on the recording medium is largely divided into penetration, drying and curing.

  Penetration means that the solvent of the colorant (ink, paint, etc.) is absorbed by the recording medium. In this case, since only the flowability of the colorant changes, the fastness of the image is not basically improved. Of course, when the binder component and the crosslinking agent are contained in the colorant, the image fastness is improved with the passage of time, but it is difficult to obtain high fastness only by penetration immediately after the image formation.

  Drying means removing the solvent of the colorant from the recording medium. In this case as well, basically, only the solvent content in the colorant is removed, so that it is difficult to obtain high fastness immediately after image formation as in the case of penetration. However, when the most common heating is selected as the means used for drying, high fastness may be obtained by using the following curing together.

  Curing is a method of fixing by changing the binder component in the coloring material. Usually, the change is a polymerization by applying energy to the binder resin, and high fastness can be obtained even immediately after image formation. As energy to be given, heat, ultraviolet rays (UV), and electron beams (EB) are generally used, and each has advantages and disadvantages.

JP 2003-145714 A Japanese Patent Laid-Open No. 10-1000037

  Heating is the most representative means used for curing, and even for materials containing solvents, there are advantages such as being able to cause a curing reaction simultaneously or continuously with solvent removal, and being able to select a wide range of materials. is doing. On the other hand, there are also disadvantages such as limited usable recording media due to heat damage and poor dimensional stability of the recording media due to thermal expansion.

  Since the curing treatment by ultraviolet irradiation, which is a technique disclosed in Patent Document 1 and the like, does not involve heat, it is more advantageous than curing by heating in that respect. However, colorants are limited, such as using ultraviolet curable ink. In addition, when the ink layer on the recording medium is thick, or in the dark part where the light absorption efficiency is high, the ultraviolet rays do not reach the deep part, so the image surface is cured but the inside is uncured. End up.

  On the other hand, since the electron beam irradiation process, which is a technique disclosed in Patent Document 2 and the like, has good transparency, preferable curing is performed even when the ink layer on the recording medium is thick or dark. It is possible. However, since secondary X-rays are emitted, it is necessary to provide a strict shielding structure for work safety.

  The object of the present invention is to provide an image fixing method that can obtain high fastness immediately after image recording and that there are no inconveniences such as the influence of heat and poor curing, which are disadvantages of conventional fixing means, and that there is no problem in safety. It is an object to provide a method, a method for producing a recorded matter using the method, and an image recording apparatus.

  In the first embodiment of the present invention, the step of fixing the image to the recording medium by performing the plasma processing on the image recorded on the recording medium using a recording agent containing a component that is cured by the plasma processing. An image fixing method is provided.

In the second aspect of the present invention,
A recording step of recording an image on a recording medium using a recording agent containing a component that is cured by plasma treatment;
Performing the plasma treatment on the recorded image;
A method for producing a recorded matter is provided.

In the third aspect of the present invention,
A recording unit for recording an image on a recording medium by applying a recording agent containing a component that is cured by plasma treatment;
A plasma processing unit for performing the plasma processing on an image recorded on the recording medium;
An image recording apparatus is provided.

In the fourth embodiment of the present invention,
An image forming unit for forming an image on the intermediate transfer member by applying a recording agent containing a component that is cured by plasma treatment;
A transfer portion for transferring an image formed on the intermediate transfer member to the recording medium;
A plasma processing unit for performing the plasma processing on the image transferred to the recording medium;
An image recording apparatus is provided.

  According to the present invention, an image recorded by various recording processes or means can be fixed immediately. In particular, the fixing means applied to the present invention has a simple structure and high robustness immediately after image recording, compared to the conventional one, and has the disadvantages of the conventional fixing means such as the influence of heat and poor curing. There is no inconvenience and there is no problem in safety. For this reason, there is little damage to a recording medium, therefore there are few restrictions of a recording medium, and it is excellent also efficiently.

  In addition, if the process or means for generating plasma at normal pressure is used, the rise time is instantaneous, no warm-up time is required, energy saving is excellent, and the entire recording apparatus can be downsized.

1. Basic Component Requirements of the Present Invention The basic component requirement of the image fixing method of the present invention is a step of fixing an image recorded on a recording medium using a recording agent containing a component that is cured by plasma processing, by plasma processing. is there. In addition, the basic structural requirements for carrying out the recorded matter manufacturing method or image recording apparatus of the present invention include a step or means for recording an image using a recording agent containing a component that is cured by plasma treatment, and the recorded image. A step or means for fixing by plasma treatment.

  Here, the recording agent is selected in relation to the image recording means to be used, and any recording agent may be used as long as it contains a component that is cured by plasma treatment. If ink is used as a recording agent, the condition is to have a curable resin component as a binder. If this condition is satisfied, the ink can be used regardless of whether it is aqueous or non-aqueous. Moreover, there is no restriction | limiting about a color, a viscosity, etc., Various inks can be used.

  There are no restrictions on the ink image recording means or process. Various forms using various recording agents are used as appropriate, from offset printing, which is the mainstream of current printing, to gravure printing, flexographic printing, screen printing, photolithography, inkjet systems, and electrophotography. be able to.

  There are no technical restrictions on the means or process for performing the plasma treatment, and it can be selected according to the required productivity. In addition, the plasma said here refers to the gas containing the charged particle produced by ionization, and defines "the state where the number of ion and electron is the same number, and space is electrically neutral." In this specification, plasma irradiation refers to imparting energy generated by plasma processing to an image recorded on a recording medium, and a plasma irradiation apparatus refers to an apparatus capable of generating such plasma. Shall.

  Further, the present invention is not limited to the case where the recorded material is directly irradiated with plasma, but also includes the case where the plasma gas generated by the plasma apparatus indirectly acts on the recorded material.

2. First Embodiment of Image Recording Apparatus An image recording apparatus according to an embodiment of the present invention will be described with reference to FIGS. However, this embodiment is merely an example, and it goes without saying that various inks, ink image recording means or processes, and plasma irradiation means or processes that satisfy the requirements of the present invention can be used.

  FIG. 1 is a schematic diagram showing an outline of an embodiment of an image recording apparatus to which the fixing method of the present invention is applied. The image recording apparatus according to this embodiment includes a process for forming an ink image on a transfer body (also referred to as an intermediate transfer body) and a process for transferring the ink image formed on the transfer body to a desired recording medium. The recording process which basically includes is performed.

  In FIG. 1, reference numeral 1 denotes a cylindrical intermediate transfer member that is rotationally driven in the direction of arrow F around an axis 1 </ b> A, and has a surface layer 2. On the outer periphery of the intermediate transfer body 1, that is, on the portion facing the surface layer 2, a coating device 4 that imparts a wettability improving component, a coating device 5 that imparts an image fixing component, and an ink image formed by dots 7 by ejecting ink. An ink jet head 6 is formed. That is, the intermediate transfer body 1 rotates in the direction of the arrow in the figure, and the wettability improving component is first applied to the surface by the coating device 4, and then the image fixing component is applied by the coating device 5. Further, after these components are applied, ink is ejected as, for example, droplets from the inkjet head 6 serving as an image forming unit, and an ink image (mirror inverted image) is formed on the surface layer 2 of the intermediate transfer body 1. . Then, the recording surface of the recording medium 10 is brought into contact with the image formed on the intermediate transfer body 1, and the image is transferred onto the recording medium 10 by applying pressure from the back surface side by the pressure roller 11 as a transfer portion. The

  A device 3 that performs plasma irradiation under normal pressure is provided as a plasma processing unit at a portion of the image recording apparatus where the recording medium after image transfer is detached from the intermediate transfer member surface layer 2. In the present embodiment, the plasma irradiation device 3 is disposed at a position where energy generated by plasma processing can be applied to the recording surface of the recording medium 10 after image transfer and the intermediate transfer member surface layer 2. .

  In the apparatus illustrated in FIG. 1, a moisture removal promoting device in the form of a blower is used to evaporate and remove the liquid component of the recording agent, that is, the moisture or solvent component in the ink constituting the image on the intermediate transfer body 1. 8 is arranged. In addition, in the illustrated apparatus, a heating roller 9 that performs heating by contacting the back side of the hollow intermediate transfer member 1 is used. However, any of these may be used.

  Further, in the apparatus illustrated in FIG. 1, the intermediate transfer member after the ink image is transferred to the recording medium 10 is washed by the next-stage cleaning unit 13 in preparation for receiving the next image for repeated use multiple times. Is done.

FIG. 2 is a block diagram showing an outline of a control system of an image recording apparatus to which the present invention can be applied.
In the image recording apparatus denoted as a whole by reference numeral 100, reference numeral 101 denotes a CPU which forms a main control unit of the entire system, and controls each unit. A memory 103 includes a ROM that stores a basic program of the CPU 101 and a RAM that is used for temporary storage of various data, processing of image data, and other work. Reference numeral 105 denotes an interface for exchanging information such as data and commands with the image data supply apparatus 110 which is an image data supply source that allows a host computer or other forms.

  Reference numeral 107 denotes a drive unit for rotationally driving the intermediate transfer member 1 in steps (a) to (c) described later. Reference numeral 109 denotes a conveyance system for the recording medium 10, which includes a driving unit for the pressure roller 11 and the conveyance roller 12. Reference numeral 120 denotes a bus line, which, in addition to the above components, connects the coating device 4, the coating device 5, the inkjet head 6, the moisture removal promoting device 8, the heating roller 9, the atmospheric pressure plasma irradiation device 3, and the cleaning unit 13, and the CPU 101 The control signal is transmitted. In addition, a state detection sensor is provided in each part to be controlled, and the detection signal can be transmitted to the CPU 101 via the bus line 120. If the image data sent from the image supply device 110 is not data that has been mirror-inverted in advance, the inversion processing is performed by the control system described above to create mirror image data.

  The reason why the exemplified image recording apparatus can effectively utilize the fixing method of the present invention will be described below.

  First, the reason why an ink jet recording method is used as the image recording means is that water-based ink is preferably used in this method. Of course, there is an ink jet recording apparatus using non-aqueous ink, and the present invention can also be applied to non-aqueous ink. However, water-based inks are suitable from the viewpoint of ink handling safety and working environment, and are expected to become more mainstream in the market in the future.

  However, water-based inks are particularly difficult to penetrate into recording media such as plastic films and other inks that are inferior in ink absorptivity. In addition, the inkjet recording method is often used for on-demand printing because different images can be output one by one. In this case, particularly, scratch resistance immediately after printing is emphasized. In recent years, a method using an ultraviolet (UV) curable recording liquid has been tried, but a material having a UV curable property is generally poorly soluble in water and difficult to be made aqueous. Furthermore, the UV curable material is likely to leave unreacted components after the curing process, and the use is greatly restricted in terms of safety.

  For this reason, the present invention can realize a fixing process that is very effective particularly in the case of performing ink jet recording using water-based ink.

  In on-demand printing, it is often required to shorten the time until the printing of the first recording medium is completed. However, a heater for fixing by general heating and an ultraviolet irradiation lamp require a relatively long standby time until it becomes stable after the power is turned on. On the other hand, since the fixing method of the present invention requires little rise time, this is also preferable.

  Furthermore, the fixing method of the present invention is particularly effective for a transfer type image recording apparatus to which an ink jet recording system is applied. The apparatus as shown in FIG. 1 that forms an ink image on an intermediate transfer member and transfers it onto a recording medium after reducing the solvent content in the ink image is particularly inferior in ink absorbability. Even on a recording medium, an image can be recorded favorably and at high speed. However, since the solvent content on the intermediate transfer member is reduced, the permeability to the recording medium is reduced, so that it is difficult to obtain high fastness, particularly scratch resistance. Therefore, the application of the fixing method of the present invention is effective because the curing tends to occur more easily because the solvent content is reduced on the intermediate transfer member.

  In addition, the image recording apparatus shown in FIG. 1 is equipped with a coating apparatus 5 for applying an image fixing component (a reaction liquid for aggregating ink). As a result, an image can be formed at high speed and without ink flow on an intermediate transfer member having no ink absorbability. However, in the case of an ink system using an agglomeration reaction, desired scratch resistance may not be obtained due to inhibition of polymerization or cross-linking of the curable component in the ink. The image fixing method of the present invention can promote crosslinking or polymerization even in such an aggregated state.

  In addition, in the embodiment of FIG. 1, a plasma irradiation device 3 as a fixing unit is also arranged facing the intermediate transfer member 1. Thereby, it is possible to make the plasma irradiation apparatus 3 function as a surface hydrophilizing apparatus of the intermediate transfer body 1.

  In order to improve the transfer rate of an ink image, it is effective to use a material having a low surface energy (generally having a characteristic of easily repelling water) as an intermediate transfer member. However, such a surface repels ink in an image forming process prior to transfer, and it becomes difficult to form a good ink image and hold it until the transfer process. However, by introducing hydrophilic groups on the surface by plasma irradiation, the surface of a material having a high transfer rate can be made hydrophilic. That is, by making the surface of the intermediate transfer member suitable for forming and holding an ink image while maintaining the original high ink transfer efficiency, it is possible to form a high-quality image without ink repelling.

  For this purpose, it is possible to arrange a separate plasma irradiation apparatus. However, in the configuration of FIG. 1, the plasma irradiation apparatus is not only used as a fixing means for an image on a recording medium, but also the surface modification of the intermediate transfer member. It also functions as a means. For this reason, both the cost and the apparatus size are very efficient.

  The surface containing a fluorine compound or a silicone compound basically employed in the present embodiment is generally a water-repellent surface, and if no treatment is performed, it will repel ink and other liquids, so Formation is difficult. In the present invention or embodiment, the reason for performing surface modification by plasma irradiation and wettability improving component application treatment (surfactant application treatment) is just to eliminate this problem, that is, ink on a surface with high ink transfer efficiency. This is because the image can be held and formed. As described above, in this embodiment, an intermediate transfer body having a surface containing a fluorine compound or a silicone compound with high ink transfer efficiency is subjected to a surface modification process by plasma irradiation and a surfactant application process. As a result, the surface of the intermediate transfer member can be made suitable for ink holding while maintaining the original high ink transfer efficiency.

  As described above, according to the image recording apparatus having the above configuration using the fixing method of the present invention, there are few restrictions on the recording medium, and it is possible to output different images for each sheet with high quality. In other words, without sacrificing the on-demand printing characteristics that are the advantages of the inkjet recording method, and without sacrificing the high speed of transfer and the versatility of the recording medium, good image robustness using safe aqueous ink A printed matter having (abrasion resistance) can be obtained.

  Note that the mechanism of image fixing by plasma irradiation has not been completely elucidated, but is thought to be as follows. That is, the curing component in the ink is cured by receiving energy. The curing reaction varies depending on the material, but it is presumed that this is a radical polymerization reaction in which a gas exposed to a high-energy plasma excited by glow discharge becomes a highly active radical and this acts. Is done.

  In the apparatus shown in FIG. 1, the intermediate transfer member after the ink image has been transferred is further washed by the cleaning unit 13 arranged in the next stage in preparation for receiving the next image. As the means for performing the cleaning, use a means for performing water cleaning or wiping while applying water in the form of a shower, direct cleaning such as contact with the water surface, or wiping such as bringing a wet Molton roller into contact with the surface. Is desirable. Of course, it is also effective to use these in combination.

  Further, if necessary, it is also effective to dry the surface of the intermediate transfer member by bringing a dry Molton roller into contact with it after washing or by blowing air. Depending on the ink used, it is also effective to perform cleaning using components that are blended for the purpose of improving wettability. In this case, the coating device 4 for applying the wettability improving component described above is also used as a cleaning unit.

  FIG. 3 is a flowchart for explaining the image recording operation performed by the configuration shown in FIGS. 1 and 2, and summarizes the above-described operations.

  In this operation, first, image processing including creation of mirror image data as required is performed (step S1), and rotation of the intermediate transfer member 1 is started (step S3). Next, it is determined whether or not the surface transfer treatment of the intermediate transfer member 1 is necessary (step S5). If necessary, the plasma irradiation device 3 is operated at this time to perform the plasma treatment on the intermediate transfer member 1 (step S6). ).

  In the course of rotation of the intermediate transfer body 1, a wettability improving component and an image fixing component are applied to the surface by the coating devices 4 and 5, respectively (step S7), and then ink is applied from the inkjet head 6 to form an ink image. Is formed (step S9). Then, along with the further rotation of the intermediate transfer body 1, moisture or solvent components in the ink constituting the image on the intermediate transfer body 1 are removed by the water removal promoting device 8 and the heating roller 9 (step S11).

  Thereafter, the recording surface of the recording medium 10 comes into contact with the ink image, and pressure is applied from the back surface side by the pressure roller 11, whereby the image is transferred onto the recording medium 10 (step S <b> 13). Then, the image transferred onto the recording medium 10 is subjected to plasma processing, thereby fixing the image onto the recording medium (step S15). After transferring the ink image, the intermediate transfer body 1 is further cleaned by a cleaning unit 13 arranged at the next stage in preparation for receiving the next image.

3. Steps and Applicable Elements According to the Method and Embodiment of the Present Invention Next, the steps according to the image fixing method and recorded product manufacturing method of the present invention and elements applicable thereto will be described in detail. Further, this description is made while appropriately relating to the configuration of the apparatus of FIG.

3-1. Recording means and process In the present invention, there is no restriction on the recording means. Analog printing means such as lithographic offset printing, letterpress printing, gravure printing, screen printing, pad printing, etc. may be used, or an electrophotographic method or a digital printing method such as the ink jet recording method described above may be employed. Further, an image may be recorded directly on a recording medium as in general letterpress printing, screen printing, or ink jet recording method, and an image created with a plate such as planographic offset printing or pad printing may be used as a blanket or You may transfer to a recording medium indirectly via a pad.

  Among these, the apparatus shown in FIG. 1 employs an intermediate transfer system to which ink jet recording is applied. That is, in the configuration of FIG. 1, the recording unit or process includes a process of forming an ink image on the intermediate transfer member and a process of transferring the image to a recording medium.

  The shape of the intermediate transfer member used in such a method may be a roller shape as described above, or may be a belt shape. In addition, those that perform continuous processing using a sheet-like intermediate transfer member or those that perform batch processing using a pad-like intermediate transfer member can be used. In the example shown in FIG. 1, a drum-shaped intermediate transfer body made of a lightweight metal such as an aluminum alloy is selected from the required characteristics such as rigidity and dimensional accuracy that can withstand the pressure during transfer and reduction of rotational inertia. ing.

  The surface layer 2 may be ink-permeable if it is not premised on repeated use of the intermediate transfer member, but if it is used repeatedly, it is made of a non-permeable material. Any material that is permeable but can be cleaned by cleaning can be used repeatedly. However, the permeable material has a poor ink transfer rate, and more ink must be applied onto the intermediate transfer body. For this reason, it is preferable from the viewpoints of material use efficiency, image quality due to dot gain (a phenomenon in which dots are largely crushed by the pressure at the time of transfer, and the diameter expands to reduce resolution), and the cleaning property of the intermediate transfer member. I can't say that.

  Therefore, from these viewpoints, the surface layer of the intermediate transfer member is preferably formed of an ink non-permeable material, and more preferably a releasable material. The releasability refers to the property that the constituent materials such as ink, image fixing component and wettability improving component are difficult to adhere to the surface. The standard as a suitable material is a state specific to the material, and the critical surface tension is 30 mN / m or less, or a surface having a contact angle with water of 75 ° or more.

  Specifically, the surface layer 2 can also be formed by subjecting the surface of the intermediate transfer member 1 to a surface treatment such as applying fluorine processing or applying silicone oil. However, it is preferable to use the surface layer 2 formed of an elastic material having releasability because higher transfer efficiency can be achieved. The rubber hardness of the surface layer material made of the elastic body is affected by the thickness and hardness of the recording medium 10 brought into contact therewith, so it is desirable to optimize the rubber hardness. However, when measured with a type A durometer (according to JIS K 6253), an effect can be obtained if the hardness is in the range of 10 to 100 °, and most of the recording is in the range of 40 to 80 °. Can handle paper. Specifically, NBR, urethane rubber, chloroprene rubber, those subjected to surface treatment thereof, or fluorine rubber, silicone rubber or fluorosilicone rubber whose material itself has ink repellent properties can be suitably used.

  Moreover, there is no restriction | limiting in particular in the surface shape of the surface layer 2, It can select in consideration of a recording medium surface shape and a printing effect. For example, if an image such as a general offset print is desired, a smooth surface shape may be selected corresponding to a smooth printing paper. On the other hand, when a rough surface or a surface such as a gravure cell is used for a smooth recording medium, a printing effect corresponding to the application can be obtained. In the following description, “intermediate transfer member surface” means “surface of the surface layer on the intermediate transfer member” unless otherwise specified.

  Moreover, there is no restriction | limiting about an ejection system also when employ | adopting an inkjet system. As energy used for ejecting ink, one using thermal energy (thermal jet method) or one using mechanical energy (piezo method) can be used. Further, not only the on-demand type but also a continuous type ink jet recording method can be appropriately selected and used. Further, as the form of the ink jet head, for example, with respect to the configuration of FIG. 1, an ink jet head in the form of a line head in which ink discharge ports are arranged in the axial direction of the intermediate transfer body 1 (direction orthogonal to the drawing) is used. It can be. Further, a head in which ejection openings are arranged in a predetermined range in the tangent or circumferential direction of the intermediate transfer body 1 may be used, and recording may be performed while scanning the head in the axial direction. In addition, the number of heads corresponding to the color of the ink used for image formation can be used.

  Also, there are no restrictions on the image to be recorded, and it can be used for all kinds of characters, illustrations, natural images, industrial patterns such as simple patterns and electronic circuits. When forming an image, ink may be ejected to form a mirror image in consideration of reversal of the image by transfer.

  The ink used in the above embodiment is an ink containing a curable component. The curing component refers to a component that accepts energy imparted by plasma treatment and becomes polymerized by a crosslinking reaction or a polymerization reaction. Since the energy applied by the plasma irradiation device is presumed that the substance is excited as described above and the highly active radicals generated thereby act on curing, the preferred material is an unsaturated group of radical polymerization. It is a material having a prepolymer and a monomer. Specifically, unsaturated polyester, unsaturated acrylic, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, polyene / polythiol, and the like. However, in experiments, it has been confirmed that even a material not corresponding to this can be cured or cured, and the present invention is not limited thereto. Accordingly, a wide range of inks including aqueous and non-aqueous, oil-based, solvent-based and the like can be used. In general, if the ink used in the present invention contains a curing component, the other components can be adjusted according to the image forming means used. The image recording apparatus illustrated in FIG. 1 uses a colored pigment ink in which a pigment is dispersed with a water-soluble acrylic resin. Water-based inks are preferable because they are less harmful to the working environment.

  As an example of the ink that can be used in the embodiment, a water-based ink having a general dye or pigment and an aqueous liquid medium for dissolving and / or dispersing the dye is suitable for the colorant. In particular, the pigment ink can obtain a recorded image with good fastness, and can obtain a particularly good image when an image fixing component described later is used. Of course, when only the printing effect is desired, colorless ink may be used.

  Examples of the dye include C.I. I Direct Blue 6, 8, 22, 34, 70, 71, 76, 78, 86, 142, 199, C.I. I Acid Blue 9, 22, 40, 59, 93, 102, 104, 117, 120, 167, 229, C.I. I Direct Red 1, 4, 17, 28, 83, 227, C.I. I Acid Red 1, 4, 8, 13, 14, 15, 18, 21, 26, 35, 37, 249, 257, 289, C.I. I Direct Yellow 12, 24, 26, 86, 98, 132, 142, C.I. I Acid Yellow 1, 3, 4, 7, 11, 12, 13, 14, 19, 23, 25, 34, 44, 71, C.I. I Food Black 1, 2, C.I. I acid black 2, 7, 24, 26, 31, 52, 112, 118 and the like.

  Examples of the pigment include C.I. Pigment Blue 1, 2, 3, 15: 3, 16, 22, C.I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 112, 122, C.I. I pigment yellow 1, 2, 3, 13, 16, 83, carbon black No 2300, 900, 33, 40, 52, MA7, 8, MCF88 (manufactured by Mitsubishi Kasei), RAVEN 1255 (manufactured by Colombia), REGAL 330R, 660R, MOGUL ( Cabot), Color Black FW1, FW18, S170, S150, Printex35 (Degussa), and the like.

  These pigments are not limited in form, and for example, any of self-dispersion type (type without dispersant), resin dispersion type, microcapsule type and the like can be used. As the pigment dispersant used in this case, a water-soluble dispersion resin having a weight average molecular weight of about 1,000 to 15,000 can be preferably used. Specifically, for example, vinyl water-soluble resins, styrene and derivatives thereof, vinyl naphthalene and derivatives thereof, aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, acrylic acid and derivatives thereof, maleic acid and derivatives thereof Derivatives, itaconic acid and its derivatives, block copolymers or random copolymers composed of fumaric acid and its derivatives, salts thereof, and the like can be mentioned.

  In order to improve the fastness of the finally recorded image, a water-soluble resin or a water-soluble crosslinking agent can be added. The material used is not limited as long as it can coexist with the ink component. As the water-soluble resin, it is preferable to further add the above-described dispersion resin or the like. As the water-soluble crosslinking agent, slow-reactive oxazoline or carbodiimide is preferably used in terms of ink stability.

  An organic solvent can be contained in the aqueous liquid medium constituting the ink together with the above-described color material. As the organic solvent to be used, the following water-soluble solvents are preferably used.

  Examples include polyethylene glycol, polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, thiodiglycol, hexylene glycol, diethylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, glycerin, and the like. Two or more kinds selected from among them can be mixed and used. Further, alcohols such as ethyl alcohol and isopropyl alcohol and surfactants can be added to the ink as components for adjusting viscosity, surface tension, and the like. Examples of the surfactant that can be used include a cationic surfactant, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, a fluorosurfactant, and a silicone surfactant. .

  The blending ratio of the components constituting the ink is not limited, and can be appropriately prepared within a dischargeable range from the selected inkjet recording method, the discharge force of the head, the nozzle diameter, and the like. Generally, on a mass basis, the color material is 0.1 to 10%, the resin component is 0.1 to 20%, the solvent is 5 to 40%, the surfactant is 0.01 to 5% or less, and the rest is pure water. The adjusted ink can be used.

  Further, in the image recording apparatus of FIG. 1, an image fixing component for aggregating the components in the recording agent can be applied onto the intermediate transfer body 1 using the coating device 5 prior to ink image formation. The reason is to control the fluidity of the ink. When the surface of the intermediate transfer member does not have ink absorbability, the ink tends to flow and the ink flows, which may cause defects such as bleeding and beading. An image fixing component is a material that reacts with or physically adsorbs a color material or resin that is part of the composition of the ink when it comes into contact with the ink, thereby reducing the flow characteristics of the entire ink. It is an effective component. Moreover, it is a component that can suppress the flow characteristics locally by agglomeration of the solid content of the ink composition, as well as when such a decrease in flow characteristics is observed.

  The image fixing component needs to be appropriately selected depending on the type of ink used for image formation. For example, it is effective to use a polymer flocculant for dye inks, and it is effective to use metal ions for pigment inks in which fine particles are dispersed. Further, when a metal ion is used in combination with a polymer flocculant as an image fixing component for the dye ink, a pigment having the same color as the dye is mixed in the ink, or the white or It is preferable to mix transparent fine particles.

Examples of the polymer flocculant used as the image fixing component include a cationic polymer flocculant, an anionic polymer flocculant, a nonionic polymer flocculant, and an amphoteric polymer flocculant. Examples of metal ions include divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ and Zn ^2+, and trivalent metals such as Fe ³⁺ and Al ^3+. Ions. And when apply | coating the liquid containing these metal ions, applying as a metal salt aqueous solution is desirable. Examples of the anion of the metal salt include Cl ⁻ , NO ³⁻ , SO ₄ ²⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ , RCOO ⁻ (R is an alkyl group) and the like. In addition, a material having a reversal to the ink used can be used as an image fixing component. For example, if the ink is anionic or alkaline, the inverse cationic or acidic material can be the image fixing component.

  As the coating device 5, a roll coater-type coating device is illustrated in FIG. 1, but the coating device 5 is not limited to this, and a known technique can be used. Specific examples include a spray coater and a slit coater. In addition, a recording head or the like that discharges a liquid having a high viscosity component by an ink jet method can be used, which is suitable when the application area is changed according to the output image.

  In the case of applying the image fixing component, it is possible to mix and apply a surfactant, a solvent, a resin component, a crosslinking agent, and the like, as in the case of the ink.

  Furthermore, the wettability of the surface of the intermediate transfer member can be increased prior to the application of the image fixing component. In the image recording apparatus of FIG. 1, the wettability improving component can be applied by using the coating apparatus 4. By applying the wettability improving component, the image fixing component can be uniformly applied onto the intermediate transfer member. As the wettability improving component, a surfactant can be suitably used. The surfactant that can be used is not limited. For example, the surface used from general cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, fluorosurfactants, silicone surfactants, etc. It can be selected depending on the layer. Among these, fluorine-based or silicone-based surfactants are highly effective and are preferable materials. As with the coating device 5, there is no limitation on the applying means, and a known technique can be used. That is, a roll coater, a spray coater, a slit coater, etc. can be used. In addition, the application area can be changed according to the output image using an inkjet head or the like.

  Further, the surfactant to be applied can be used even if it is not liquid. For example, a wettability improving component can be imparted by bringing a solid or waxy surfactant into contact or sliding contact with the surface of the intermediate transfer member.

  Note that some of the above components applied prior to ink image formation may be preferably ejected after being dried. For this purpose, the ink is applied from the application of the component to the ink. An appropriate delay time may be set before ejection. In the case of the apparatus of FIG. 1, it is possible to appropriately reduce or stop the rotation of the intermediate transfer member 1.

  The recording apparatus of FIG. 1 includes a process of transferring an ink image formed on the intermediate transfer body 1 to a recording medium. That is, the ink image formed on the intermediate transfer body 1 is transferred by being brought into contact with the recording surface of the recording medium 9 by the pressure roller 10. According to the apparatus configuration of FIG. 1, since the ink is sufficiently high in viscosity on the intermediate transfer body 1 by this stage, the recording medium paper having a small ink absorption amount or the plastic having no ink absorption amount is used. Good image recording can be performed on a recording medium such as a film.

  However, if the increase in viscosity is still insufficient, it is effective to promote this with the water removal promoting device 8 and / or the heating roller 9 in the form of a blower arranged between ink image formation and transfer. On the other hand, it is possible to add a means for suppressing the volatilization of the solvent in the ink or to adjust the volatility of the ink solvent to be used in preparation for excessive increase in viscosity.

3-2. Fixing the image By applying the above energy to the ink image transferred onto the recording medium by plasma treatment, which is the main feature of the present invention, the cured component in the ink is polymerized, and sufficient image fastness is obtained. Prints can be completed. In the apparatus of FIG. 1, the apparatus 3 that performs plasma irradiation at normal pressure fulfills its function, which is disposed at a portion of the image recording apparatus where the recording medium after image transfer is detached from the intermediate transfer member surface layer 2. The plasma irradiation device 3 is disposed at a position where energy can be applied to the recording surface of the recording medium 10 after image transfer and the surface layer 2 of the intermediate transfer member. It is possible to increase the surface energy of the body surface.

4). Examples Next, more specific examples and comparative examples of the present invention will be described. In the following description, “parts” and “%” are based on mass unless otherwise specified.

(4.1) Example 1
Recording Step In this example, a printed matter was prepared by supplying offset ink having the following formulation to a roller and transferring the ink on the roller to printing paper via a blanket.
(Offset ink)
Carbon black: 20 parts Alkali blue toner: 4 parts Phthalocyanine blue: 2 parts Rosin modified phenolic resin: 30 parts Linseed oil: 10 parts High-boiling petroleum solvent (boiling point: about 260 ° C): 30 parts Dryer (cobalt, manganese-based): 2 copies Compound: 2 copies (printing paper)
Art paper (62.5 g (JIS P 0001))

Fixing Step Next, the printed material was cut in half, and one of the printed materials was subjected to plasma irradiation under the following conditions to fix the image to obtain Sample 1A.
(Plasma irradiation conditions)
Processing pressure: Normal pressure Introducing gas: Nitrogen gas 0.5 l / min Processing voltage: 230V
Processing current: 1.85A
Processing frequency: 30 kHz
Processing speed: 70mm / sec

Comparative Example On the other hand, the remaining half of the printed material was not subjected to plasma irradiation, and this was used as Sample 1B.

Fixability Evaluation Test Samples 1A and 1B thus obtained were immediately tested with a wear resistance tester (weighted 200 g, 50 times) to evaluate the fixability. As a result, in the sample 1A, the character image hardly deteriorated and the good readability was maintained, but in the sample 1B, the image was disturbed and the readability was remarkably deteriorated.

(4.2) Example 2
Recording process Using a commercially available inkjet printer, a photographic image is formed on a dedicated OHP film (Canon: CF-102) using the inks of the following prescription (four color inks containing each color dye as a coloring material) did. In this embodiment, there is no transfer process.
(Ink formulation)
Each of the following dyes: 4 parts Black: C.I. I Food Black 2
Cyan: C.I. I Direct Blue 199
Magenta: C.I. I Acid Red 289
Yellow: C.I. I Acid Yellow 23
Styrene-acrylic acid-ethyl acrylate copolymer: 2 parts (acid value 240, weight average molecular weight 5000)
Glycerin: 10 parts Ethylene glycol: 5 parts Surfactant: 1 part (manufactured by Kawaken Fine Chemicals: Acetylenol EH)
Ion exchange water: 78 parts

Fixing Step Next, the printed OHP film was cut into three equal parts, and one of the sheets was irradiated with plasma under the following conditions to fix the ink image to obtain Test Sample 2A.
One of the samples was subjected to plasma irradiation under the following conditions to fix the image to obtain Sample 2A.
(Plasma irradiation conditions)
Processing pressure: Normal pressure Introducing gas: Nitrogen gas 0.5 l / min Processing voltage: 230V
Processing current: 1.85A
Processing frequency: 30 kHz
Processing speed: 100mm / sec

Comparative Example One of the prints divided into three equal parts was not subjected to plasma irradiation, and this was used as sample 2B. Further, the remaining one sheet was irradiated with infrared rays by an IR heater under the following conditions to obtain Sample 2C.
(Infrared irradiation conditions)
Applied voltage: 90V
Applied current: 5A
Processing speed: 100m / sec

Fixability Evaluation Test Samples 2A, 2B, and 2C thus obtained were immediately tested with a wear resistance tester (loading 200 g · 50 times) to evaluate fixability. As a result, the image of the sample 2A was not disturbed, and the OHP film was not damaged. In sample 2B, the image was disturbed, and the image quality was significantly deteriorated. In sample 2C, the image was not disturbed, but the OHP film was wavy due to heat.

(4.3) Example 3
Recording Process In this example, an aluminum drum coated with a silicone rubber (manufactured by Shin-Etsu Chemical: KE30) having a rubber hardness of 60 ° with a thickness of 0.5 mm was used as an intermediate transfer member in the apparatus configuration of FIG. . First, the surface of the intermediate transfer member was irradiated with plasma under the following conditions by a plasma irradiation device arranged as a fixing device.
(Plasma irradiation conditions)
Processing pressure: Normal pressure Introducing gas: Nitrogen gas 0.5 l / min Processing voltage: 230V
Processing current: 1.70A
Processing frequency: 30 kHz
Processing speed: 120mm / sec

Next, the following aqueous solution was applied onto the intermediate transfer member with a roll coater.
(Aqueous solution)
Calcium chloride dihydrate: 10 parts Fluorosurfactant: 1 part (Surflon S-141 manufactured by Seimi Chemical Co., Ltd.)
Crosslinking agent: 1 part (Nisshinbo Carbodilite V-02)
Ion exchange water: 88 parts

Next, using an ink jet recording apparatus (nozzle arrangement density 1200 dpi, ejection amount 4 pl, driving frequency 8 kHz), a mirror is formed on the intermediate transfer body using the inks of the following prescription (four color inks including each color pigment as a coloring material). An inverted photographic image was formed.
(Ink formulation)
Each of the following pigments: 5 parts Black: Carbon black (Mitsubishi Chemical: MCF88)
Cyan: Pigment Blue 15
Magenta: Pigment Red 7
Yellow: Pigment Yellow 74
Styrene-acrylic acid-ethyl acrylate copolymer: 1 part (acid value 240, weight average molecular weight 5000)
Glycerin: 10 parts Ethylene glycol: 5 parts Surfactant: 1 part (manufactured by Kawaken Fine Chemicals: Acetylenol EH)
Ion exchange water: 78 parts

Transfer Process A blower type moisture removing device 8 installed between the inkjet head 6 and the pressure roller 11 sent warm air to the surface of the formed image on the intermediate transfer member to reduce moisture in the ink image. Thereafter, the intermediate transfer member and printing paper (Npi Coat made by Nippon Paper Industries, 40.5) were brought into contact with a pressure roller to transfer an ink image.

The printed material on which the image of the fixing process was transferred was subjected to plasma irradiation by the plasma irradiation device 3 under the following conditions. This was designated as test sample 3A.
(Plasma irradiation conditions)
Processing pressure: Normal pressure Introducing gas: Nitrogen gas 0.5 l / min Processing voltage: 230V
Processing current: 1.7A
Processing frequency: 30 kHz
Processing speed: 100mm / sec

Comparative Example The printed matter obtained up to the transfer step similar to that in Example 3 was taken out without passing through the fixing step (plasma treatment), and this was designated as Sample 3B.

Fixability evaluation test The test samples 3A and 3B thus obtained were tested with a wear resistance tester (loading 200 g, 50 times) with a time from the transfer of the ink image to the start of the wear test being 10 minutes, and the fixability was evaluated. did. As a result, the fixing property of sample 3A was better than that of sample 3B.

5). Second Embodiment In the first embodiment, an intermediate transfer method using ink jet recording is employed, and for image recording, a process of forming an ink image on an intermediate transfer member, and the image is transferred to a recording medium. Process. However, as described above, there are no restrictions on the recording means in the present invention, and image recording is not limited to intermediate transfer. That is, a system that performs direct recording on the recording surface of the recording medium 10 may be used.

  FIG. 4 is an example of an image recording apparatus according to the embodiment, and the same reference numerals are given to corresponding portions of the respective portions having the same functions as the respective portions according to the first embodiment. Needless to say, appropriate modifications and additions similar to those described above can be added to each part.

  In the case of this example, the recording medium 10 is supported by a conveyor belt 112 stretched between a pair of conveyor rollers 112A with the recording surface facing upward. Then, the image fixing component is conveyed under the coating device 5, the inkjet head 6, the moisture removal promoting device 8, and the plasma irradiation device 3.

FIG. 5 is a flowchart for explaining the image recording operation of the present embodiment.
In this operation, first, image processing including creation of image data as necessary is performed (step S21), and driving of the transport roller 112A or the transport belt 112 is started (step S23). In the process of transporting the recording medium 10 accompanying this, a reaction liquid is applied to the surface by the apparatus 5 (step S27), and then ink is applied from the inkjet head 6 which is a recording unit, and image recording is performed. (Step S29). Then, as the recording medium 10 is further conveyed, the moisture or the solvent component in the ink constituting the image is removed by the moisture removal promoting device 8 (step S31). Then, a plasma process is performed on the recorded image to perform a fixing process (step S35).

1 is a schematic diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating an example of a control system that can be configured corresponding to the image forming apparatus of FIG. 1. FIG. 3 is a flowchart for explaining an image recording operation performed by the configuration shown in FIGS. 1 and 2. FIG. It is a schematic diagram which shows schematic structure of the image forming apparatus which concerns on other embodiment of this invention. 6 is a flowchart for explaining an image recording operation performed by the configuration shown in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate transfer body 2 Surface layer 3 Normal pressure plasma irradiation apparatus 4, 5 Coating apparatus 6 Inkjet recording apparatus 8 Moisture removal promotion apparatus 9 Heating roller 10 Recording medium 11 Pressure roller

Claims (9)

  An image comprising a step of fixing the image to the recording medium by performing the plasma processing on the image recorded on the recording medium using a recording agent containing a component that is cured by the plasma processing. Fixing method. A recording step of recording an image on a recording medium using a recording agent containing a component that is cured by plasma treatment;
Performing the plasma treatment on the recorded image;
A method for producing recorded matter, comprising: The recording step includes
Providing the intermediate transfer member with the recording agent to form an image; and
Transferring the image formed on the intermediate transfer member to the recording medium;
The method for producing a recorded matter according to claim 2, wherein:   4. The method for producing a recorded matter according to claim 3, further comprising a step of reducing a liquid component of a recording agent applied on the intermediate transfer body between the image forming step and the transfer step. .   The method for producing a recorded matter according to claim 3, further comprising a step of aggregating components in the recording agent applied on the intermediate transfer member.   4. The method for producing a recorded matter according to claim 3, further comprising a step of performing plasma processing on the intermediate transfer body before forming an image on the intermediate transfer body. A recording unit for recording an image on a recording medium by applying a recording agent containing a component that is cured by plasma treatment;
A plasma processing unit for performing the plasma processing on an image recorded on the recording medium;
An image recording apparatus comprising: An image forming unit for forming an image on the intermediate transfer member by applying a recording agent containing a component that is cured by plasma treatment;
A transfer portion for transferring an image formed on the intermediate transfer member to the recording medium;
A plasma processing unit for performing the plasma processing on the image transferred to the recording medium;
An image recording apparatus comprising:   The image recording apparatus according to claim 8, wherein the plasma processing unit can perform the plasma processing on the intermediate transfer body in order to perform surface modification of the intermediate transfer body.

Images