Image forming method and image forming system

Abstract

To provide an image forming method that, when forming an image on a substrate by using powder, can remove excess powder that is the cause of image noise.SOLUTION: An image forming method for forming an image on a substrate by using powder includes the steps of: attaching a protective material to a surface of the substrate on which the image is formed; forming an attachment layer on at least either one of the substrate or the protective material attached to the substrate; attaching powder to the attachment layer after the step of attaching the protective material; and removing, from the protective material, excess powder not attached to the attachment layer and attached to the protective material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image forming method and an image forming system for forming an image on a substrate using powder.

Background Art

[0002] In recent years, in the on-demand printing market, the demand for special printing and high-value-added printing has been increasing. Among them, the demand for decorative printing such as metallic printing is particularly large, and various studies have been conducted.

[0003] As one of the methods of decorative printing, a method of forming an image with ink or toner on a substrate and attaching powder only to the image is known.

[0004] However, in the method of attaching powder to an image, the powder may adhere to the background portion where the image does not exist. Originally, it is desired to supply powder only to the image portion to give a desired appearance. Therefore, the powder adhering to such a background portion is surplus powder. These surplus powders are visually recognized as image noise as powder stains on the background portion.

[0005] Also, Patent Document 1 proposes a method of landing ink on the surface of a recording medium, applying powder before the ink dries, and thermally fixing it. And in this Patent Document 1, an elimination unit for eliminating the powder that did not adhere to the ink is provided, and unnecessary powder is eliminated by this elimination unit (for example, a brush or an air blow). By providing such an elimination unit, it is possible to roughly eliminate the surplus powder adhering to the background portion, which is a factor of image noise due to powder stains.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the method proposed in Patent Document 1, it was difficult to remove all the surplus powder from the surface of the base material (recording medium, paper, etc.). In addition, when the removing part contacts the base material or applies a pushing force to the surface of the base material, the powder may penetrate into the fibers of the base material (paper), or the powder may be pushed into the recesses on the surface of the base material, making these powders impossible to remove.

[0008] FIGS. 10A and 10B are photographs showing a state where powder has penetrated into the fibers of the base material. As shown in FIGS. 10A and 10B, powder has penetrated into the fibers of the base material. In the portions circled with 〇 in each photograph, relatively large powder has penetrated, so it is considered that image noise increases.

[0009] In addition, in order to apply a force to contact the surface of the base material, it is necessary to closely attach the removing part to the unevenness of the surface of the base material. However, if the removing part closely attaches with a high pressure, it may damage the surface of the base material.

[0010] In order to solve the above-described problems, the present invention provides an image forming method and an image forming system capable of removing surplus powder that causes image noise when forming an image on a base material using powder.

Means for Solving the Problems

[0011] The image forming method of the present invention is an image forming method for forming an image on a base material using powder. And the image forming method of the present invention includes a step of attaching a protective material to the surface of the base material on which the image of the base material is to be formed, a step of forming an adhesion layer on at least one of the base material or the protective material attached to the base material, a step of attaching powder to the adhesion layer after the step of attaching the protective material, and a step of removing surplus powder that has adhered to the protective material without adhering to the adhesion layer from the protective material. It has a protective material which is a film with an adhesive layer laminated on a sheet-like base material layer and adheres to the base material by a heating and pressing process.

[0012] The image forming system of the present invention is an image forming system that forms an image on a substrate using powder. The image forming system of the present invention includes a protective material attaching device that attaches a protective material to the surface of the substrate on which the image of the substrate is formed, an adhesion layer forming device that forms an adhesion layer on at least one of the substrate or the protective material attached to the substrate, and a powder image forming device that attaches powder to the adhesion layer to form a powder image. Furthermore, the powder image forming device includes a powder supply unit that attaches powder to the adhesion layer, and a cleaning unit that removes excess powder attached to the protective material without attaching to the adhesion layer from the protective material. It has a protective material which is a film with a transparent base material layer and an adhesive layer laminated thereon. The protective material attaching device heats and presses the protective material to attach the protective material to the base material. .

Effects of the Invention

[0013] According to the image forming method of the present invention, the substrate in the portion without the adhesion layer is protected by the protective material, and the excess powder does not directly adhere to the substrate but adheres to the protective material, preventing the excess powder from entering the substrate. Then, since the excess powder attached to the protective material is removed from the protective material, it becomes possible to reliably remove the excess powder.

[0014] According to the image forming system of the present invention, the excess powder can be made to adhere to the protective material without directly adhering to the substrate. Further, after the powder is attached by the powder supply unit, the excess powder attached to the protective material can be removed by the cleaning unit.

Brief Description of the Drawings

[0015]

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Figure 10

Embodiments for Carrying Out the Invention

[0016] The image forming method of the present invention is an image forming method for forming an image on a base material using powder. And the image forming method of the present invention includes a step of attaching a protective material to the surface of the base material on which the image is to be formed, a step of forming an adhesion layer on at least one of the base material or the protective material attached to the base material, a step of attaching powder to the adhesion layer after the step of attaching the protective material, and a step of removing excess powder attached to the protective material without attaching to the adhesion layer from the protective material.

[0017] The image forming system of the present invention is an image forming system for forming an image on a base material using powder. And the image forming system of the present invention includes a protective material attaching device for attaching a protective material to the surface of the base material on which the image is to be formed, an adhesion layer forming device for forming an adhesion layer on at least one of the base material or the protective material attached to the base material, and a powder image forming device for attaching powder to the adhesion layer to form a powder image. Furthermore, the powder image forming device has a powder supply unit for attaching powder to the adhesion layer and a cleaning unit for removing excess powder attached to the protective material without attaching to the adhesion layer from the protective material.

[0018] (Base material) In the image forming method of the present invention and the image forming system of the present invention, the base material is a recording medium on which an image is to be recorded. As the base material, paper, resin film, or the like can be used.

[0019] In addition, in the present invention, the protective material can prevent powder from adhering to the base material, and can prevent the generation of background image noise caused by the powder penetrating into the fibers of the base material. Therefore, according to the present invention, even when using a base material into which powder easily penetrates, for example, uncoated, fiber-exposed, high-quality paper or fancy paper, an image without background image noise can be obtained.

[0020] (Protective material) Regarding the protective material according to the image forming method of the present invention and the image forming system of the present invention, any material can be used as long as it adheres to the base material and protects the base material of the background portion.

[0021] Note that the adhesion force of the protective material to the base material only needs to be greater than the force exerted by the cleaning unit of the powder image forming apparatus. That is, the protective material should not be peeled off from the base material by the force exerted by the cleaning unit. If the protective material is peeled off, powder will adhere to the base material from which the protective material has peeled off and become background noise, so this is to prevent this.

[0022] Also, the protective material is preferably not altered or deformed by heating in the step of attaching powder to the adhesion layer. In the step of attaching powder to the adhesion layer, the adhesion layer (heat-melting material, toner) is in contact with the powder in a state where the adhesive force is manifested by heating. At this time, the protective material is also heated and in contact with the powder. If the protective material is a thermoplastic material and softens or melts at the heating temperature in the powder attachment step, it may be deteriorated and the adhesive force with the powder may increase, or the surface may be deformed and adhere closely to the powder, resulting in the possibility that the powder adheres and is fixed to the protective material. If the powder adheres to the protective material, it will become background image noise. In order not to deteriorate or deform the surface of the protective material in the powder attachment step, it is preferable to use a protective material in which the melting temperature Th of the protective material is higher than the melting temperature Tf of the adhesion layer. Then, in the heating step, if the temperature of the substrate is adjusted to a temperature higher than the melting temperature Tf of the adhesion layer and lower than the melting temperature Th of the protective material, and the adhesion layer is selectively melted, it is possible to prevent the remaining powder from adhering strongly to the protective material and becoming background image noise.

[0023] As one form of the protective material, for example, a sheet-like protective material can be mentioned. Using this sheet-like protective material, it can be adhered to the substrate. Also, it may be a film in which an adhesive layer is laminated on a sheet-like substrate layer, and it adheres to the substrate by the adhesive force of the adhesive layer and acts as a protective material. The sheet-like protective material may be a colored film such as a gold foil film, but it is preferably transparent or translucent so as not to damage the appearance of the substrate. For example, a transparent foil or a laminate film can be used. The sheet-like protective material can be attached to the entire surface of the substrate on which the image is formed.

[0024] Also, as another form of the protective material, the protective material may be supplied to the substrate and cured to adhere the protective material to the substrate. As such a protective material, for example, an electrophotographic toner which is heated and pressed after being supplied to a substrate by an electrophotographic process, cured with cooling, and fixed to the substrate, an ultraviolet curable ink which is cured by irradiation with ultraviolet rays after being supplied to the substrate and adheres to the substrate, a thermosetting ink which is cured by heating after being supplied to the substrate and adheres to the substrate, etc. can be used. Any of the above-mentioned protective materials such as toner and ink may be colored such as color toner and color ink, but it is preferable that they are transparent or translucent in the same way as in the case of a film because they do not damage the appearance of the substrate. For example, clear toner (transparent toner), clear ink, and clear varnish can be used. The above-mentioned protective materials such as toner and ink can be adhered to either a part of the surface or the entire surface of the surface on which the image of the substrate is formed.

[0025] When the protective material is adhered to the entire surface of the surface on which the image of the substrate is formed, the entire background portion is protected with the protective material, and background portion image noise can be surely prevented over the entire surface.

[0026] Not limited to the above examples, any material that adheres to the substrate and can protect the substrate from the action of the cleaning unit of the powder image forming apparatus can be used as the protective material.

[0027] (Adhesion layer) The adhesion layer fixes the powder on the substrate. As the material of the adhesion layer, for example, toner can be used. Then, for example, after forming toner on the substrate and heating it, the toner softens or melts, and the powder adheres to the softened or melted toner. Note that the adhesion layer may be any material that can be cured by temperature or light irradiation and can fix the powder, and is not limited to toner.

[0028] (Powder) In the image forming method and the image forming system of the present invention, powder is used to form an image constituted by the powder. In the present invention, the powder to be used is a powder having properties such that an image can be formed by the powder. Examples of such properties of the powder include, for example, the property of exhibiting metallic luster for performing the metallic printing described above.

[0029] Examples of the powder having the property of exhibiting metallic luster include powders of bright pigments such as powders containing metal powders. And the metal powder contains metals such as aluminum, silver, platinum, chromium, nickel, rhodium, iron, gold, copper, etc.

[0030] The powder may be a synthetic product or a commercially available product. The powder is composed of, for example, aggregated powder particles. Examples of the powder particles include metal particles, resin particles, magnetic particles, and non-magnetic particles. Also, the powder particles may be composed of two or more different materials. And the powder may be a mixture of two or more different powder particles.

[0031] The powder particles constituting the powder may be coated. For example, the metal particles may be coated with a metal, metal oxide, or resin different from the metal, or the surface of a resin or glass may be coated with a metal or metal oxide. Also, the metal particles may be metal oxide particles, and further, the metal oxide particles may be coated with a metal oxide, metal, or resin different from the metal oxide. Also, the metal particles may be those obtained by extending and pulverizing a metal or metal oxide into a plate shape, those coated with various materials, or those obtained by vapor-depositing or wet-coating a film or glass with a metal or metal oxide.

[0032] Note that the powder used in the present invention is different from toner. Toner is obtained by attaching color particles to charged plastic particles.

[0033] In particular, when forming an image with powder by utilizing the property of exhibiting a metallic luster of the powder, it is preferable that the powder has a non-spherical shape (non-spherical). And non-spherical powder preferably has a flat particle shape from the viewpoint of orienting and adhering non-spherical powder along the surface of an adhesion layer such as a toner layer. The "flat particle shape" of non-spherical powder means that when the maximum length in the particles of non-spherical powder is defined as the major axis, the maximum length in the direction orthogonal to the major axis is defined as the minor axis, and the minimum length in the direction orthogonal to the major axis is defined as the thickness, it is a shape in which the ratio of the minor axis to the thickness is 3 or more. The thickness of the non-spherical powder is preferably 0.2 to 10 μm, more preferably 0.2 to 5.0 μm, from the viewpoint of sufficiently exhibiting the appearance effect due to the oriented adhesion of the non-spherical powder. If the thickness is too small, it is difficult to recover the overlapping powder, and a good orientation state in which the planar direction of the non-spherical powder, including the major axis direction and the minor axis direction of the non-spherical powder adhered to the surface of the adhesion layer, substantially follows the surface direction of the adhesion layer may not be sufficiently formed. Furthermore, the powder may be broken in the apparatus and the size of the powder may change. On the contrary, if the thickness is too large, the powder may come off when the image is rubbed. Also, the lengths of the major axis and the minor axis of the non-spherical powder are preferably 1 to 50 μm, more preferably 15 to 50 μm. If the major axis and the minor axis are too small, handling becomes difficult and there are concerns about the influence on the human body. On the contrary, if the major axis and the minor axis are too large, the image resolution becomes low and the image has low gradation. The material of the non-spherical powder is not particularly limited as long as it has the properties that enable the formation of the aforementioned image.

[0034] Specific examples of powders having the property of exhibiting metallic luster include Sunshine Baby Chrome Powder, Aurora Powder, Pearl Powder (all manufactured by GG Corporation), ICEGEL Mirror Metal Powder (manufactured by TAT Corporation), Pika Ace MC Shine Dust, Effect C (manufactured by Kuchi Corporation, "Pika Ace" is the company's registered trademark), PREGEL Magic Powder, Mirror Series (manufactured by Priance Co., Ltd., "PREGEL" is the company's registered trademark), Bonnail Shine Powder (manufactured by K's Planning Co., Ltd., "BON NAIL" is the company's registered trademark), Meta Shine (manufactured by Nippon Sheet Glass Co., Ltd., "Meta Shine" is the company's registered trademark), LG neo (manufactured by Oike Kogyo Co., Ltd.).

[0035] The above description has been made for powders having the property of exhibiting metallic luster, that is, powders of glitter pigments. However, the present invention can also be applied to other powders other than powders of glitter pigments. Examples of other powders include powders that give effects such as coloring other than metallic luster to an image. Specifically, powders of fluorescent pigments and pearl-like luster pigments can be mentioned. Also, it is not limited to powders that give effects such as coloring to an image, and functional powders that exhibit functions other than color development may be used. The effects of the present invention are exhibited in any method of attaching a powder to an adhesion layer on a substrate. On the other hand, when the powder of the glitter pigment adheres to the background portion, even if the number of the adhered powders is small, the image noise of the background portion is easily recognized due to the glitter, and the present invention is more preferably used.

[0036] (Protective material adhesion step) In the method for forming an image of the present invention, in the step of adhering a protective material (protective material adhesion step), for example, a protective material is adhered to a substrate using a protective material adhesion device. In the method for forming an image of the present invention, the protective material adhesion step is performed before the step of adhering a powder to the adhesion layer (powder image forming step).

[0037] Prior to the protective material adhesion step, it is also possible to perform a step of forming an image different from the image using powder (powder image) on the base material. Examples of the different image include, for example, the four-color toner image of Example 2 described later, and the like. By performing the step of forming a different image on the base material prior to the protective material adhesion step in this way, the different image can be protected by the protective material, and background noise can be prevented even in an image with high added value that combines the powder image and the different image.

[0038] (Protective material adhesion device) As the protective material adhesion device according to the image forming method of the present invention and the image forming system of the present invention, any device that can supply and adhere the protective material to the base material can be used regardless of the method and system, and devices with various configurations can be used.

[0039] (Protective material adhesion device for sheet-like protective material) As the protective material adhesion device for adhering a sheet-like protective material (for example, a transparent foil or a laminate film), for example, a laminator device can be used.

[0040] FIG. 2 shows a schematic configuration diagram of one form of the laminator device. The laminator device 200 shown in FIG. 2 includes a roll-shaped laminate film (protective material) 41, a roll-shaped backup film 42, a pair of rollers including an upper roller 43 and a lower roller 44, and a roller group for moving the base material 11 and the films 41, 42. In the figure, 45 indicates a table for supporting the base material 11 and the films 41, 42.

[0041] The base material 11 moves from left to right in FIG. 2. The laminate film (protective material) 41 is unwound from the roll and then supplied onto the base material 11 by the upper roller 43. The backup film 42 is unwound from the roll and then supplied under the base material 11 by the lower roller 44.

[0042] The upper roller 43 and the lower roller 44 of the roller pair are configured to be able to come into contact and apply pressure. By overlapping and passing the sheet-shaped protective material 41 and the base material 11 through the contact portion of these rollers 43 and 44, the protective material 41(12) is adhered to the base material 11 by the adhesive layer of the protective material 41. Also, a protective material 41 using a thermoplastic material for the adhesive layer is prepared, and the roller pair 43 and 44 is made into a device that can be heated. Thus, the adhesive layer heated at the contact portion of the roller pair 43 and 44 softens and adheres to the base material 11, and after passing through the contact portion of the roller pair 43 and 44, it hardens with cooling, so that a type in which the protective material 12 and the adhesive layer adhere to the base material 11 is known.

[0043] Note that the backup film 42 is a film for preventing the adhesive layer of the laminate film (protective material) 41 from adhering to a roller group such as the lower roller 44. Then, the backup film 42 is peeled off from the base material 11 at a portion (not shown) on the right side of the laminator device 200 in FIG. 2. By peeling the backup film 42 from the base material 11, a base material 11 to which the protective material 41(12) is adhered is obtained.

[0044] In the description of the above laminator device 200, an example in which the protective material 41(12) is adhered over a large area by the roller pair 43 and 44 that heats and presses has been described, but this is not the only case. It may be a device that only presses the adhesive layer of the protective material against the base material to make it adhere, or it may be a device that includes a thermal head that can be heated according to an input signal and selectively adheres the protective material by heating only the necessary portion of the base material.

[0045] (Protective material adhesion device for protective materials such as ink and varnish) For example, an inkjet device can be used as a device for adhering a protective material such as clear ink or clear varnish to a base material. In an inkjet device, an inkjet head is arranged with a minute gap with respect to the base material, and ink (varnish) droplets land on the base material according to an input signal. The landed ink hardens by cooling or light irradiation. In the case of an ultraviolet curable ink (varnish), a UV light source for irradiating the ink (varnish) with ultraviolet light after landing is provided, and the ink (varnish) hardens by the irradiation of ultraviolet light.

[0046] By using an inkjet device, it is possible to form a protective material such as ink or varnish on a part of the surface or the entire surface of the substrate on which the image of the substrate is formed.

[0047] (Adhesion layer formation step) In the image forming method of the present invention, in the step of forming an adhesion layer (adhesion layer formation step), for example, using an adhesion layer forming device, an adhesion layer, for example, the toner described above, is formed on at least one of the substrate or the protective material adhered to the substrate. In this step of forming the adhesion layer (adhesion layer formation step), the adhesion layer is formed on any one of only the substrate, only the protective material adhered to the substrate, or the substrate and the protective material adhered to the substrate.

[0048] When the protective material is formed on the entire surface of the substrate on which the image of the substrate is formed in the protective material adhesion step, after the protective material adhesion step, the adhesion layer is formed only on the protective material adhered to the substrate. When the protective material is formed on a part of the surface of the substrate on which the image of the substrate is formed in the protective material adhesion step, the adhesion layer formation step can be performed before or after the protective material adhesion step, and the adhesion layer is formed on only the substrate or on the substrate and the protective material adhered to the substrate. And in this case, the protective material and the adhesion layer are formed on the substrate so as not to overlap each other, or the later formed one is formed over the previously formed one so that a part of the protective material and the adhesion layer overlaps.

[0049] When forming the protective material and the adhesion layer on the substrate so that they do not overlap each other, control is performed so that a gap where the substrate is exposed hardly occurs between the protective material and the adhesion layer, and the protective material and the adhesion layer are formed respectively. If a gap where the substrate is exposed occurs, there is a risk that powder will adhere to the exposed substrate. Further, when forming the later-formed one so as to partially overlap the one formed earlier among the protective material and the adhesion layer, over the one formed earlier from the substrate, no gap where the substrate is exposed occurs between the protective material and the adhesion layer.

[0050] The step of forming the adhesion layer (adhesion layer forming step) can be executed, for example, by adopting an electrophotographic method.

[0051] (Adhesion layer forming apparatus) As the adhesion layer forming apparatus according to the image forming method of the present invention and the image forming system of the present invention, any apparatus can be used regardless of the method or system as long as it can supply the adhesion layer to at least one of the substrate or the protective material adhered to the substrate and form the adhesion layer. As the adhesion layer forming apparatus, for example, an adhesion layer forming apparatus adopting an electrophotographic method such as AccurioPress C2060 manufactured by Konica Minolta, Inc. can be used.

[0052] (Powder image forming step) In the step of adhering powder to the adhesion layer (powder image forming step) in the image forming method of the present invention, for example, powder is adhered to the adhesion layer using a powder image forming apparatus.

[0053] (Removing step) In the step of removing excess powder adhered to the protective material without adhering to the adhesion layer from the protective material (removing step) in the image forming method of the present invention, for example, the excess powder is removed using a cleaning unit provided in the powder image forming apparatus.

[0054] (Powder image forming apparatus) Regarding the powder image forming apparatus according to the image forming method of the present invention and the image forming system of the present invention, any apparatus that can supply powder to the adhesion layer and adhere the powder to the adhesion layer can be used regardless of the method or system, and apparatuses with various configurations can be used. Further, as the powder image forming apparatus, it is desirable to have a cleaning unit that removes excess powder adhered to the protective material from the protective material without adhering to the adhesion layer.

[0055] Regarding the cleaning unit of the powder image forming apparatus, any configuration can be adopted regardless of the method or system as long as it can remove excess powder adhered to the protective material from the protective material. Examples of the cleaning unit include a brush roller or the like in which fibers made of PET, nylon, acrylic, etc. are wound around a core metal to form a cleaning member.

[0056] Note that the powder image forming apparatus, the protective material adhering apparatus, and the adhesion layer forming apparatus may be independent apparatuses, or may be apparatuses in which two or three apparatuses are connected, or may be one apparatus including two or three apparatuses.

[0057] According to the image forming method of the present invention, after the step of adhering a protective material to the surface of the substrate on which the image of the substrate is to be formed, powder is adhered to the adhesion layer. Therefore, the substrate in the portion without the adhesion layer is protected by the protective material, and excess powder does not directly adhere to the substrate but adheres to the protective material. Then, since the excess powder adhered to the protective material without adhering to the adhesion layer is removed from the protective material, it becomes possible to surely remove the excess powder.

[0058] According to the image forming system of the present invention, it includes a protective material adhering apparatus that adheres a protective material to the surface of the substrate on which the image of the substrate is to be formed, an adhesion layer forming apparatus that forms an adhesion layer on at least one of the substrate or the protective material adhered to the substrate, and a powder image forming apparatus that adheres powder to the adhesion layer to form a powder image. Thereby, after the protective material adhering apparatus adheres the protective material to the substrate to protect the substrate, the powder image forming apparatus forms a powder image so that excess powder does not directly adhere to the substrate but adheres to the protective material. According to the image forming system of the present invention, further, since the powder image forming apparatus includes a powder supply unit that adheres powder to the adhesion layer and a cleaning unit that removes excess powder adhered to the protective material without adhering to the adhesion layer from the protective material, after the powder is adhered by the powder supply unit, the excess powder adhered to the protective material can be removed by the cleaning unit.

[0059] Hereinafter, specific embodiments of the image forming method and the image forming system of the present invention will be described with reference to the drawings and the like.

[0060] (Form of Powder Image Forming Apparatus) As a specific embodiment of the present invention, one form of the powder image forming apparatus according to the present invention will be described. FIG. 1 is a schematic configuration diagram of one form of the powder image forming apparatus according to the present invention.

[0061] The powder image forming apparatus 100 shown in FIG. 1 is an apparatus that adheres powder 14 onto an adhesion layer 13 formed on a base material 11 in a predetermined pattern. As shown in FIG. 1, the powder image forming apparatus 100 includes a supply unit 20 in the region surrounded by the dotted line, a heating member 31, and a cleaning unit composed of a mandrel 32 and a cleaning member 33 around it.

[0062] The supply unit 20 is composed of a powder storage unit 21, a first supply member 22, a second supply member 23, and an opposing member 24 that opposes the second powder supply member 23. The powder 14 is stored in the powder storage unit 21, and while the first supply member 22 holds the powder 14, it is transferred to the second supply member 23. The powder 14 held by the second supply member 23 is oriented on the second supply member 23 by contact with the first supply member 22.

[0063] The thin layer of powder 14 from which the surplus powder 14 has been removed is supplied to the adhesion layer (hot-melt material image) 13. The hot-melt material of the adhesion layer 13 is heated by the heating member 31 and comes into contact with the powder 14 in a state where the adhesive force is developed. Due to the developed adhesive force and pressure, the powder 14 on the second supply member 23 adheres closely to the adhesion layer 13 (hot-melt material image). If there are multiple layers of powder 14 between the second supply member 23 and the adhesion layer 13, poor adhesion may occur because the powder 14 pressurized on the second supply member 23 is different from the powder that actually contacts the adhesion layer 13. Since the powder 14 is in a thin layer on the second supply member 23 in advance, the powder 14 pressurized on the second supply member 23 directly contacts the adhesion layer 13, and the powder 14 adheres closely. Furthermore, assuming that powder (surplus powder) 14 adheres to the area (background part) on the base material 11 where the adhesion layer (hot-melt material image) 13 does not exist, the cleaning member 33 is operated to collect the surplus powder 14 in the background part.

[0064] In the powder storage unit 21, a member (not shown) for stirring and transporting the powder 14 may be provided. If the first supply member 22 and the second supply member 23 can hold and transfer the powder 14, various sponges, brushes, solid rollers, etc. may be used to control the powder 14 by electrostatic force, magnetic force, adhesive force, etc.

[0065] In the powder image forming apparatus 100 of FIG. 1, the heating member 31 is heated without contacting the base material 11. In the present invention, either a contact or non-contact heating method may be adopted as long as the hot-melt member of the adhesion layer can be heated. For example, the opposing member 24 in FIG. 1 may be configured to also serve as a heating member.

[0066] As the cleaning unit, the above-described brush roller in which fibers made of PET, nylon, acrylic, etc. are wound around the core metal 32 to form the cleaning member 33 can be used. Also, regarding the cleaning member of the cleaning unit, a plate-shaped member (not shown) may be brought into contact with the brush roller to remove the powder 14 held on the surface of the brush roller from the surface of the brush roller.

[0067] The powder adhesion process of the powder adhesion device is not limited to the method of bringing the powder 14 into contact with the adhesion layer 13 from the second supply member 23 as shown in the powder image forming device 100 of FIG. 1. For example, a method of applying a driving force that moves toward the substrate to the powder stored in the powder storage layer to bring the powder into contact with the substrate and the adhesion layer may be used. As the driving force, gravity acting on the powder, vibration by a piezoelectric element, or the like can be used. And it is not limited to the method of the powder adhesion process described above, and the effects of the present invention are exhibited in any method of bringing the powder into contact with the substrate and the adhesion layer.

Example

[0068] Using a protective material and powder, an image of the protective material and powder was actually formed on the substrate, and the characteristics were examined.

[0069] (Substrate) As the substrate, the following papers, namely, npi high quality with exposed paper fibers and POD gloss coat with a coat on the surface, were used. POD gloss coat 128g A4 size manufactured by Oji Paper Co., Ltd. npi high quality 128g A4 size manufactured by Nippon Paper Industries Co., Ltd.

[0070] (Protective material) As the protective material, a protective material formed on the entire surface of the substrate on which the image is formed, or a protective material formed on a part of the surface of the substrate on which the image is formed (the background portion of the powder image), was used. As the protective material formed on the entire surface of the substrate on which the image is formed, TOLAMI NS-PP mat manufactured by Tokyo Lamnex Co., Ltd. was used. As the protective material formed on a part of the surface of the substrate on which the image is formed (the background portion of the powder image), UV varnish for JetVarnish3DS manufactured by MGI Digital Technology was used.

[0071] (Adhesion layer) The material of the adhesion layer (thermally fusible material) used was the toner (black) of the AccurioPress C2060 manufactured by Konica Minolta, Inc.

[0072] (Powder) For the powder, Elgee neo #325 (manufactured by Horigane Foil Powder Co., Ltd.) was used. Elgee neo has a resin layer coated on the surface of the metal layer and is an insulating powder.

[0073] (Protective material adhesion device 1) As the protective material adhesion device 1, the WIDE FORMAT LAMINATOR RSL-382S manufactured by Royal Sovereign was used. The heater set temperature on the upper roller side of the roller pair was set to 120°C, the heater set temperature on the lower roller side was set to 120°C, and the speed setting was set to 0.7 m / min.

[0074] (Protective material adhesion device 2) As the protective material adhesion device 2, the JetVarnish 3DS manufactured by MGI Digital Technology was used. The UV varnish landing on the base material was dried and cured by the LED-UV built into the device.

[0075] (Adhesion layer forming device) As the adhesion layer forming device, the AccurioPress C2060 manufactured by Konica Minolta, Inc. was used.

[0076] (Powder image forming device) As the powder image forming device, the powder image forming device 100 with the configuration shown in FIG. 1 was used. The first supply member 22 and the second supply member 23 were configured to hold and supply the powder 14 by adhesive force. For the first supply member 22, a nitrile rubber roller with a diameter of Φ30 was used, and for the second supply member 23 and the opposing member 24, silicone rubber rollers with a diameter of Φ60 were used. As the heating member 31, a plate heater (MPHK-V200-W150) was used and brought into contact with the back side of the base material 11.

[0077] As the cleaning member 33, a brush roller was used to contact the excess powder 14 on the surface of the base material 11. Fibers were wound around the core metal 32 to form the brush roller, and the fibers were rotated in contact with the surface of the base material 11. Then, the rotation direction of the cleaning member (brush roller) 33 was made the same as the moving direction of the base material 11, and by making the moving speed of the surface of the brush roller 33 higher than the moving speed of the base material 11, a force for moving the powder 14 on the base material 11 was applied. Then, by holding the powder 14 on the brush roller 33, the excess powder 14 was removed from the base material 11.

[0078] (Comparative Example 1) First, the base material 11 was passed through the above-described adhesion layer forming apparatus, and a toner image was printed on the base material 11 as the adhesion layer 13. The printed toner image is shown in the plan view of FIG. 3A. As shown in FIG. 3A, a black circular adhesion layer 13 is formed at the center of the blank paper of the base material 11 by black toner. Next, the base material 11 on which the adhesion layer 13 composed of the toner image was formed was passed through the powder image forming apparatus 100 shown in FIG. Inside the powder image forming apparatus 100, the powder 14 on the second supply member 23 adhered to the toner (adhesion layer) 13. The printed powder image is shown in the plan view of FIG. 3B. As shown in FIG. 3B, the powder 14 is adhered to the central circular portion.

[0079] (Comparative Example 2) The powder image (FIG. 3B) formed in Comparative Example 1 was passed through the above-described protective material adhesion apparatus 1, and the protective material 12 was adhered to the base material 11 and the powder 14. The formed image is shown in the plan view of FIG. 3C. As shown in FIG. 3C, the protective material 12 was adhered to the central circular powder 14.

[0080] (Example 1) First, the base material 11 shown in the plan view of FIG. 4A was passed through the above-described protective material adhesion apparatus 1, and the protective material 12 was adhered to the base material 11. The formed image is shown in the plan view of FIG. 4B. As shown in FIG. 4B, the protective material 12 is adhered to the entire surface of the base material 11. Next, the substrate 11 with the protective material 12 attached was passed through the above-described adhesion layer forming apparatus, and a toner image was printed on the protective material 12 as the adhesion layer 13. The printed toner image is shown in the plan view of FIG. 4C. As shown in FIG. 4C, a black circular adhesion layer 13 is formed by black toner in the center of the substrate to which the protective material 12 is attached. Next, the substrate 11 having the toner image and the protective material 12 was passed through the powder image forming apparatus 100 shown in FIG. 1. Inside the powder image forming apparatus 100, the powder 14 adhered to the toner (adhesion layer) 13. The printed powder image is shown in the plan view of FIG. 4D. As shown in FIG. 4D, the powder 14 is adhered to the central circular portion.

[0081] (Example 2) First, the substrate 11 was passed through an image forming apparatus. As the image forming apparatus, AccurioPress C6020 manufactured by Konica Minolta was used, and a four-color toner image was formed on the substrate 11. The printed four-color toner image is shown in the plan view of FIG. 5A. As shown in FIG. 5A, star-shaped toner images 15 in four colors were formed at the upper left and lower right of the substrate 11. Next, the substrate 11 having the toner image 15 was passed through the above-described protective material attaching apparatus 1, and the protective material 12 was attached to the substrate 11. The formed image is shown in the plan view of FIG. 5B. As shown in FIG. 5B, the protective material 12 is attached to the entire surface of the substrate 11 including above the toner image 15 indicated by the star mark. Next, the substrate 11 having the toner image 15 and the protective material 12 was passed through the above-described adhesion layer forming apparatus, and a toner image was printed on the protective material 12 as the adhesion layer 13. The printed toner image is shown in the plan view of FIG. 5C. As shown in FIG. 5C, a black circular adhesion layer 13 is formed by black toner in the center of the protective material 12 attached to the substrate. Next, the base material 11 having the toner image and the protective material 12 was passed through the powder image forming apparatus 100 shown in FIG. 1. Inside the powder image forming apparatus 100, the powder 14 adhered to the toner (adhesion layer) 13. The printed powder image is shown in the plan view of FIG. 5D. As shown in FIG. 5D, the powder 14 is adhered to the central circular portion. On the other hand, the powder 14 is not adhered to the star-shaped toner image 15 protected by the protective material 12. Thereby, an image in which the powder image and the four-color toner image are arranged in one plane as shown in FIG. 5D is formed.

[0082] (Modification 1) Modification 1 is an example in which the protective material attaching apparatus 2 is used as another form of Example 1. First, the base material 11 shown in the plan view of FIG. 6A was passed through the above-described protective material attaching apparatus 2 to attach the protective material 12 to the base material 11. The formed image is shown in the plan view of FIG. 6B. As shown in FIG. 6B, the protective material 12 was adhered to the background portion of the surface of the base material 11 where no image is formed in the subsequent process. Next, the base material 11 having the protective material 12 was passed through the above-described adhesion layer forming apparatus, and a toner image was printed on the protective material 12 as the adhesion layer 13. The printed toner image is shown in the plan view of FIG. 6C. As shown in FIG. 6C, a black circular adhesion layer 13 is formed by black toner in the central portion where the protective material 12 is not adhered among the base materials 11 to which the protective material 12 is adhered to the background portion. Next, the base material 11 having the toner image and the protective material 12 was passed through the powder image forming apparatus 100 shown in FIG. 1. Inside the powder image forming apparatus 100, the powder 14 adhered to the toner. The printed powder image is shown in the plan view of FIG. 6D. As shown in FIG. 6D, the powder 14 is adhered to the central circular portion.

[0083] In this Modification 1, specifically, the protective material 12 was adhered so as to partially overlap with the image (powder image) formed in the subsequent process. Here, Fig. 7A shows a cross-sectional view of the case where UV varnish is landed on the base material 11 as the protective material 12 so that the protective material 12 adheres exactly only to the background part. Due to errors in paper conveyance or the like, as shown in Fig. 7A, a gap 16 may be formed between the adhesion layer 13 formed by the toner image and the protective material 12. When there is such a gap 16, since the base material 11 is exposed, the powder 14 may adhere to the exposed base material 11 in the powder adhesion step, which may result in background part image noise. On the other hand, Fig. 7B shows a cross-sectional view of the case where UV varnish is landed on the base material 11 so that the protective material 12 adheres to an area wider than the background part. Even if there is an error in paper conveyance, as shown in Fig. 7B, since the adhesion layer 13 formed by the toner image adheres to ride (overlap) partially on the protective material 12, no gap is generated and the base material 11 is not exposed. As a result, there is no background part image noise.

[0084] (Modification Example 2) Modification Example 2 is an example in which the order of the protective material adhesion step and the adhesion layer formation step in Modification Example 1 is reversed. First, the base material 11 shown in the plan view of Fig. 8A was passed through the above-described adhesion layer forming apparatus, and a toner image was printed on the base material 11 as the adhesion layer 13. The printed toner image is shown in the plan view of Fig. 8B. As shown in Fig. 8B, a black circular adhesion layer 13 was formed in the center of the blank paper by black toner. Next, the base material 11 having the toner image was passed through the above-described protective material adhesion apparatus 2 to adhere the protective material 12 to the base material 11. The formed image is shown in the plan view of Fig. 8C. As shown in Fig. 8C, the protective material 12 was adhered to the background part on the surface of the base material 11 where the toner image was not formed. Next, the base material 11 having the toner image and the protective material 12 was passed through the powder image forming apparatus 100 shown in Fig. 1. The powder 14 adhered to the toner inside the powder image forming apparatus 100. The printed powder image is shown in the plan view of Fig. 8D. As shown in Fig. 8D, the powder 14 was adhered to the central circular part.

[0085] The protective material 12 was adhered so as to partially overlap with the toner image (adhering layer) 13. A cross-sectional view of the base material 11 when UV varnish was landed so that the protective material 12 adhered to an area wider than the background portion is shown in FIG. 7C. As shown in FIG. 7C, since a part of the protective material 12 adheres to ride on (overlap with) the toner image (adhering layer) 13, even if there is an error in paper conveyance, no gap is generated and it does not become background image noise.

[0086] (Method for evaluating background image noise) The background image noise of the powder adhesion images of each example formed as described above was evaluated by the following method. For the evaluation, papers of POD gloss coat 128 and npi premium 128 were used. However, for Modification Example 1 and Modification Example 2, since JetVarnish 3DS manufactured by MGI Digital Technology used as the protective material adhesion device 2 does not support premium paper, only POD gloss coat 128 was evaluated.

[0087] Powder was placed on the laminated paper and spread on the paper by rubbing with a microfiber cleaning cloth. Furthermore, the powder on the paper was collected by rubbing with a microfiber cleaning cloth. Then, by changing the number of rubs, samples with the level of background image noise on the paper changed were prepared, and sensory evaluation was performed on a plurality of people. A sample for which 90% of the subjects answered that it was acceptable was set as the OK level and designated as an "○ sample", and a sample for which 50% of the subjects answered that it was acceptable was designated as a "△ sample". FIG. 9A shows an observation image of the above △ sample, and FIG. 9B shows an observation image of the above ○ sample. In each observation image, the observed powder is indicated by being surrounded by 〇.

[0088] Then, the number of adhered powders in the background portion was counted and calculated by the method described below. Using a digital microscope VHX-6000 (manufactured by Keyence Corporation), observations were made in a mode where multiple screens were automatically acquired and combined, and images were saved at an angle of view of 5 mm × 5 mm. Then, after binarizing the saved images using the image processing software attached to the device, the number of powders contained within the angle of view was automatically counted. From the obtained number and the area of the angle of view, the number of powders adhering to the background part (unit: pieces / cm 2 ) was calculated.

[0089] For each evaluation sample of each example, three measurements were taken at three locations, and the average value of the three locations was used as the number of powders adhering to the background part of each evaluation sample.

[0090] The number of powders adhering to the background part obtained by counting and calculating using the above method was 10 pieces / cm for the ○ sample 2 , and 80 pieces / cm for the △ sample 2 . Based on this, for each evaluation sample of each example, if the number of powders adhering to the background part is less than 10 pieces / cm 2 , it was determined as "○", if it is 10 pieces / cm or more and less than 80 pieces / cm 2 , it was determined as "△", and if it is 80 pieces / cm or more 2 , it was determined as "×". 2 In the observation image of Fig. 9A, powders were also observed other than the powders surrounded by ○, and the number of powders adhering to the background part was measured at three locations including the illustrated observation image and the average value was taken. Therefore, the value of the number of powders adhering to the background part described above is different from the calculated value obtained from the number of ○ in the illustrated observation image and the area of the observation image.

[0091] The printing process order and the evaluation results of the background part image noise of each comparative example, each example, and each modified example are shown in Table 1.

[0092]

Table 1

[0093] In Comparative Example 1, the protective material adhesion step was not performed. Therefore, in the powder image formation step inside the powder image forming apparatus, the powder contacts the exposed substrate. As a result, after the removal step, powder remained in the recesses of the paper on the surface of the POD gloss coat, and background image noise occurred. For npi premium 128, the background image noise further deteriorated. When observed with a microscope, as shown in FIGS. 10A and 10B, the powder had penetrated into the paper fibers. For these images, attempts were made to clean by rubbing with a microfiber rag and by contacting an adhesive rubber surface, but the powder remaining in the recesses and the powder that had penetrated into the paper fibers could not be removed.

[0094] In Comparative Example 2, since the protective material adhesion step by the laminating apparatus was provided after the powder image formation step, in the powder image formation step, the powder contacts the exposed substrate. As a result, powder pushed into the recesses and powder that had penetrated into the paper fibers occurred after the removal step, and background image noise occurred. Further, in Comparative Example 2, since the protective material was adhered on the powder that had penetrated into the paper fibers, it was impossible to remove those powders.

[0095] In Example 1, a protective material adhesion step by a laminating apparatus was provided before the adhesion layer formation step and the powder image formation step. Therefore, in the powder image formation step, the laminate contacts the powder, and the powder does not contact the substrate. And even if powder adheres to the laminate, it is not pushed into the recesses in the removal step, and background image noise did not occur. Even for the slightly remaining powder, it was possible to remove it by rubbing the surface of the laminate with a macro fiber rag. In Example 1, since the entire surface of the substrate is protected by the laminate, there is no risk of the substrate being exposed, and background image noise can be reliably prevented. Also, compared with the case where the protective material is adhered only at a desired position according to the input signal, the protective material adhesion apparatus can be easily configured. And in Example 1, even when using npi high-quality 128 with deteriorated background image noise in Comparative Example 1 and Comparative Example 2 as the base material, since the paper fibers were protected in the powder adhesion process, the powder did not penetrate into the paper fibers, and no background image noise occurred.

[0096] In Example 2, a protective material adhesion process using a laminating device was provided before the adhesion layer formation process and the powder image formation process. For this reason, the laminate contacted the powder, the powder did not contact the base material, and no background image noise occurred. As shown in FIG. 5D, even in an image in which the four-color toner image and the powder image were arranged within one surface, an image without background image noise could be obtained.

[0097] In Modification 1, a protective material adhesion process using UV varnish was provided before the adhesion layer formation process and the powder image formation process. For this reason, in the powder image formation process, the toner contacted the powder in the image area, the UV varnish contacted the powder in the background area, and the powder did not contact the base material. Therefore, even if the powder adhered to the UV varnish, it was not pushed into the recesses in the removal process, and no background image noise occurred. Even for the slightly remaining powder, it was possible to remove it by wiping the surface of the UV varnish with a macro fiber cleaning cloth. In Modification 1, since the protective material was adhered only to the necessary parts, the usage area of the protective material could be reduced, that is, the consumption amount of the protective material could be reduced.

[0098] In Modification 2, a protective material adhesion process using UV varnish was provided after the adhesion layer formation process and before the powder image formation process. In the powder image formation process, the toner contacted the powder in the image area, the UV varnish contacted the powder in the background area, and the powder did not contact the base material. Therefore, even if the powder adhered to the UV varnish, it was not pushed into the recesses in the removal process, and no background image noise occurred. Even for the slightly remaining powder, it was possible to remove it by wiping the surface of the UV varnish with a macro fiber cleaning cloth.

[0099] Since it is important that the protective material adheres to the background part in the powder image forming process, the protective material adhesion process may be before the powder image forming process, and may be before or after the adhesion layer forming process.

Explanation of Signs

[0100] 11 Substrate, 12 Protective material, 13 Adhesion layer, 14 Powder, 15 Toner image, 16 Void, 20 Supply unit, 21 Powder storage unit, 22 First supply member, 23 Second supply member, 24 Opposing member, 31 Heating member, 32 Core metal, 33 Cleaning member, 41 Laminate film (protective material), 42 Backup film, 43 Upper roller, 44 Lower roller, 100 Powder image forming apparatus, 200 Laminator apparatus

Claims

1. An image forming method for forming an image on a substrate using powder, comprising: a step of attaching a protective material to the surface of the substrate on which the image is to be formed; a step of forming an adhesion layer on at least one of the substrate or the protective material attached to the substrate; a step of attaching the powder to the adhesion layer after the step of attaching the protective material; a step of removing excess powder attached to the protective material without attaching to the adhesion layer from the protective material, wherein the protective material is a film in which an adhesive layer is laminated on a sheet-like substrate layer, and is attached to the substrate by a heating and pressing step Image forming method.

2. An image forming system for forming an image on a substrate using powder, comprising: a protective material attaching device for attaching a protective material to the surface of the substrate on which the image is to be formed; an adhesion layer forming device for forming an adhesion layer on at least one of the substrate or the protective material attached to the substrate; a powder image forming device for attaching the powder to the adhesion layer to form a powder image, wherein the powder image forming device has a powder supply unit for attaching the powder to the adhesion layer and a cleaning unit for removing excess powder attached to the protective material without attaching to the adhesion layer from the protective material, wherein the protective material is a film in which a transparent substrate layer and an adhesive layer are laminated, and the protective material attaching device heats and presses the protective material to attach the protective material to the substrate Image forming system.

Images