JP2014019552A - Thermal transfer device and glossy image forming apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a glossy image forming apparatus capable of preventing reduction in glossiness or gloss unevenness caused by irregularities of a surface of a transfer resin layer, even when supply energy is high in the whole or a part of an image area.SOLUTION: The thermal transfer device includes: heating means for heating a glossy sheet in a state where the glossy sheet having a base material sheet and a transfer resin layer overlaps with a body to be transferred so that the transfer resin layer is in contact with the body to be transferred; cooling means for cooling the glossy sheet heated and bonded to a surface of the body to be transferred; and peeling means for peeling the base material sheet away from the glossy sheet bonded to the surface of the body to be transferred.

Description

  The present invention relates to a glossy image forming apparatus that forms a glossy image by attaching a glossy sheet to the surface of a toner image formed using an electrophotographic system.

  In an image forming apparatus using an electrophotographic system, for example, a toner image is formed through steps of charging, exposure, development, transfer, and fixing.

  In recent years, colorization techniques in electrophotographic image forming apparatuses have rapidly developed, and full-color image forming apparatuses have been developed and provided to the market. The market for full-color image forming apparatuses is expanding with the spread of black-and-white image forming apparatuses. Generally, for color reproduction in a full-color image forming apparatus, three subtractive primary colors, yellow (Y), magenta (M), cyan (C), or black (K) are added to these three colors. Four color toners are used.

  In addition, there is an increasing demand for such a color image to give gloss to an image such as a photograph instead of a simple print or copy.

  In response to such a demand, for example, Patent Document 1 discloses glossiness by providing a smooth thermal transfer layer on the surface of a toner image by heating the surface of the paper on which the toner image is fixed by superimposing a thermal transfer sheet. A protective layer forming method for improving the thickness is disclosed.

  FIG. 6 is a schematic diagram showing the thermal transfer process disclosed in Patent Document 1. As shown in FIG. This document discloses a method in which a transfer medium 62 and a thermal transfer sheet 63 are sandwiched between a heat roller 60 and a platen roller 61 and heating from the heat roller 60 is performed. Further, in front of the heat roller 60, detectors (64, 64 ′) for aligning the transfer target 62 and the thermal transfer sheet 63 are provided.

JP 2009-137253 A (released on June 25, 2009)

  However, in the method for forming a protective layer using the thermal transfer sheet disclosed in Patent Document 1, if the heating temperature is too low, the resin of the thermal transfer sheet is not completely dissolved, and the image cannot have sufficient glossiness. Since a gloss unevenness in which an image region having a partially low gloss appears, a sufficient heating temperature is required. However, if the heating is performed at a temperature higher than the temperature at which the resin is melted in the entire image area, the heating temperature may be too high in the whole or a part of the image area. If the heating temperature is too high, the temperature will not be sufficiently lowered when the substrate sheet is peeled from the surface of the thermal transfer layer. If the temperature remains high, the viscosity (elasticity) of the resin becomes lower than necessary, and the resin pulls a short thread due to the force when the base sheet is peeled from the surface of the thermal transfer layer. Micron-order protrusions are formed. And as the resin naturally cools and hardens as it is, unevenness remains on the surface of the thermal transfer layer in the entire image area, glossiness decreases, or unevenness remains on the surface of the thermal transfer layer in some image areas, Since uneven gloss occurs, there is a problem that it is difficult to uniformly control the supply energy in the entire image area.

  An object of the present invention is to provide a glossy image forming apparatus capable of preventing a reduction in glossiness and uneven glossiness caused by unevenness of the surface of a transfer resin layer even when supply energy is increased in all or a part of an image area. That is.

  The thermal transfer apparatus according to the present invention includes a heating unit that heats a transfer sheet in a state where the transfer resin layer of a glossy sheet having a base sheet and a transfer resin layer is in contact with the transfer target; A cooling means for cooling the glossy sheet heated and adhered to the body surface, and a peeling means for peeling the base sheet from the glossy sheet adhered to the surface of the transfer target.

  The cooling means may be a heat sink.

  The cooling means may be a hollow metal member.

  The cooling means may be a blower means.

  Moreover, you may provide the pressurization means which applies a pressure in the state to which the said to-be-transferred body and the said glossy sheet were adhere | attached.

  A glossy image forming apparatus according to the present invention includes any one of the thermal transfer apparatuses described above.

  According to the present invention, it is possible to realize a glossy image forming apparatus capable of preventing a reduction in glossiness and uneven glossiness caused by unevenness of the surface of a transfer resin layer even when supply energy is high in all or a part of an image area. Can do.

1 is a configuration diagram of a glossy image forming apparatus according to the present invention. 1 is a schematic diagram of a thermal transfer apparatus according to the present invention. It is sectional drawing of a glossy sheet. It is the schematic which shows the example of a cooling means. It is the schematic which shows the example of a cooling means. It is the schematic which shows the conventional thermal transfer process.

  Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples embodying the present invention, and do not limit the technical scope of the present invention.

  FIG. 1 is a configuration diagram of a glossy image forming apparatus 50 according to an embodiment of the present invention. The glossy image forming apparatus 50 in this embodiment includes an image forming apparatus 200 that heats and fixes a toner image on the surface of a recording medium to generate a toner image recording medium, and a thermal transfer apparatus 100 that thermally transfers a glossy sheet to the surface of the toner image recording medium. The thermal transfer apparatus 100 is installed on the side of the image forming apparatus 200 so that the toner image recording medium that is configured and discharged from the image forming apparatus 200 is continuously conveyed to the thermal transfer apparatus 100.

  The image forming apparatus 200 includes a developing device housing portion 200A in which a plurality of developing devices 202a to 202d are housed in a casing, and a fixing device housing portion 200B in which a fixing device 212 is housed above the developing device housing portion 200A in the casing. And a partition wall 230 provided between them to insulate the heat of the fixing device 212 from being transmitted to the developing device side, and in accordance with image data transmitted from the outside, a sheet-like recording medium (recording) The color printer can generate a toner image recording medium in which the toner image is fixed on the surface of the recording medium by heating the toner image after the toner image is formed and supported on a sheet.

  As shown in FIG. 1, the developing device housing section 200A includes four photosensitive drums 203a to 203d, four charging devices 205a to 205d for charging the surfaces of the photosensitive drums 203a to 203d, and each photosensitive drum. An exposure unit (exposure device) 201 that forms electrostatic latent images on the surfaces 203a to 203d, and black, cyan, magenta, and yellow color toners are individually accommodated to electrostatically charge the surfaces of the photosensitive drums 203a to 203d. Four developing devices 202a to 202d for developing a latent image to form a toner image; cleaner units 204a to 204d for removing residual toner remaining on the surfaces of the photosensitive drums 203a to 203d after development and image transfer; Four toner supply devices 222a to 22 for individually supplying the four color toners to the developing devices 202a to 202d, respectively. And d, the intermediate transfer belt unit (transfer unit) 208 which the toner image on the surface of the photosensitive drum 203a~203d onto a recording medium, such as an intermediate transfer belt cleaning unit 209 is housed.

  Further, the developing device housing portion 200A is set with a paper feed tray 210 that houses a plurality of recording media disposed at the bottom thereof, and an irregular size recording medium that is disposed on one side surface of the developing device housing portion 200A. A manual feed tray 220, and a sheet transport path S for transporting a recording medium from the paper feed tray 210 or the manual feed tray 220 to the intermediate transfer belt unit 208.

  In each of the members indicated by reference numerals having a to d, a is a member for forming a black image, b is a member for forming a cyan image, c is a member for forming a magenta image, and d is a member for forming a yellow image. It is a member.

  Since the photosensitive drums 203a to 203d corresponding to the respective colors have the same configuration, in the description of these configurations, the reference numeral is unified to 203. Similarly, the developing device has the reference numeral 202, the charging device has the reference numeral 205, and the cleaner. The unit is denoted by reference numeral 204, and the toner replenishing device is denoted by reference numeral 222.

  The developing device 202 contains a two-component developer containing toner and a carrier, supplies the two-component developer to the surface of the photosensitive drum 203, and generates an electrostatic latent image formed on the surface of the photosensitive drum 203. It is an apparatus that visualizes an image by attaching toner.

  The photosensitive drum 203 is a cylindrical member that is composed of a conductive substrate and a photosensitive layer formed on the surface thereof, and is responsible for forming a latent image by charging and exposure. An electrical image called an electrostatic latent image is formed.

  As the charging device 205, a charging device such as a contact roller type, a contact brush type, or a non-contact charger type is used, and the surface of the photosensitive drum 203 is uniformly charged to a predetermined potential.

  The exposure unit 201 passes light between the charging device 205 and the developing device 202 and irradiates the surface of the charged photosensitive drum 203 with light corresponding to the image data, thereby exposing the photosensitive drum 203. An electrostatic latent image corresponding to the image data is formed on the surface. In this embodiment, the case where an LSU (laser scanning unit) provided with a laser irradiation unit and a reflection mirror is used as the exposure unit 201 is exemplified, but EL (electroluminescence) in which light emitting elements are arranged in an array. Alternatively, an LED write head can be used.

  The intermediate transfer belt unit 208 includes an intermediate transfer belt 207 and intermediate transfer rollers 206a to 206d (hereinafter referred to as 206) that stretch the intermediate transfer belt 207 and rotate it in the direction of arrow B in FIG. A driving roller 271, a driven roller 272, a belt tension mechanism (not shown), and a transfer roller 211 disposed adjacent to the side of the driving roller 271, and disposed above each photosensitive drum 203. ing.

  Further, an intermediate transfer belt cleaning unit 209 is disposed on the side of the driven roller 272 of the intermediate transfer belt unit 208. In addition, the driving roller 271 and the driven roller 272 are arranged outside the photosensitive drums 203 on both sides of the four photosensitive drums 203 so that the intermediate transfer belt 207 contacts each photosensitive drum 203. Transfer of the toner image from each photosensitive drum 203 to the intermediate transfer belt 207 is performed by each intermediate transfer roller 206 in contact with the inner surface of the intermediate transfer belt 207.

  The intermediate transfer roller 206 is covered with a metal shaft (for example, made of stainless steel) having a diameter of, for example, 8 to 10 mm, and a conductive elastic material layer that covers the outer peripheral surface of the metal shaft. In this embodiment, the intermediate transfer roller 206 is used as the transfer electrode, but a brush or the like can also be used.

  The toner images stacked on the outer surface of the intermediate transfer belt 207 move to the position (transfer portion) of the transfer roller 211 as the intermediate transfer belt 207 rotates. On the other hand, the recording medium is also conveyed to the transfer section through the sheet conveying path S, and the transfer roller 211 presses the recording medium toward the intermediate transfer belt 207, whereby the toner image on the intermediate transfer belt 207 is transferred onto the recording medium. Is done.

  The toner remaining on the intermediate transfer belt 207 without being transferred from the intermediate transfer belt 207 to the recording medium is removed and collected by the intermediate transfer belt cleaning unit 209.

  As shown in FIG. 1, the sheet conveyance path S leads from a paper feed tray 210 and a manual feed tray 220 to a paper discharge tray 215 through a fixing device 212 and a thermal transfer device 100 described later. 225a to 225f (hereinafter referred to as 225), a registration roller 214, a transfer roller 211, a fixing device 212, and the like are arranged.

  The conveyance rollers 225 are small rollers for promoting and assisting conveyance of the sheet, and a plurality of pairs are provided along the sheet conveyance path S.

  The registration roller 214 temporarily holds the recording medium being conveyed through the sheet conveyance path S, and conveys the recording medium to the transfer unit at the timing when the leading edge of the toner image on the intermediate transfer belt 207 is aligned with the leading edge of the recording medium. Is.

  As shown in FIG. 1, the fixing device 212 accommodated in the fixing device accommodating portion 200 </ b> B includes a heat roller 281 and a pressure roller 282 that rotate in opposite directions with a recording medium on which a toner image is transferred, and a conveyance A roller 225b and a conveyance (paper discharge) roller 225c are provided.

  The heat roller 281 is controlled by a control unit (not shown) so as to have a predetermined fixing temperature. This control unit controls the temperature of the heat roller 281 based on a detection signal from a temperature detector (not shown). The heat roller 281 and the pressure roller 282 that have been heated to the fixing temperature are pressed against the recording medium to melt the toner, thereby fixing the toner image on the recording medium. The recording medium on which the toner image is fixed is conveyed to the thermal transfer apparatus 100 by the conveyance rollers 225b and 225c, and is discharged from the recording medium supply roller 102 onto the paper discharge tray 215 via the base sheet peeling roller 106.

  As the color toner that can be used in the image forming apparatus 200, for example, colored resin particles having a volume average particle diameter of 5 μm or more and 8 μm or less including a binder resin, a colorant, a charge control agent, and a release agent are used.

  Examples of the binder resin include styrene acrylic resin, polyester resin, and epoxy resin. Moreover, you may use resin obtained by mixing the mold release agent mentioned later with a raw material monomer mixture, and performing a polymerization reaction. Binder resin can be used individually by 1 type, or may use 2 or more types together. Among these binder resins, polyester is excellent in transparency, and can be imparted to toner particles with good powder fluidity, low-temperature fixability, secondary color reproducibility, etc., and is therefore suitable as a binder resin for color toners. is there.

  As the colorant, conventionally known ones that constitute color toners of yellow, magenta, cyan, and black can be used.

The colored resin particles may contain a charge control agent as required in addition to the binder resin and the colorant. As a method for producing the colored resin particles, for example, a dry method such as a kneading and pulverization method, and a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsification method can be used. Paraffin wax and derivatives thereof, microcrystalline wax, polyethylene wax, polypropylene wax, carnauba wax and the like can be used.

  FIG. 2 is a schematic diagram of the thermal transfer apparatus 100 shown in FIG. The thermal transfer apparatus 100 includes a glossy sheet supply roller 101, recording medium supply rollers 102a and 102b, a heating member 103, pressure members 104a and b, cooling members 105a and b, base sheet peeling rollers 106a and b, and base sheet recovery. A roller 107 is provided.

  The glossy sheet supply roller 101 is a cylindrical roller that rotates around a rotation shaft around which the glossy sheet 1 is wound around a cylindrical peripheral surface, and supplies the glossy sheet 1 to the recording medium supply rollers 102a and 102b.

  The recording medium supply rollers 102a and 102b are cylindrical rollers that rotate about a rotation axis, and the transfer resin layer of the glossy sheet is in contact with the toner image surface fixed on the toner image recording medium 2. After the glossy sheet having the base sheet and the transfer resin layer is overlaid, the sheet is supplied to the heating member 103. The conveying speed of the toner image recording medium 2 is preferably 50 mm / second to 200 mm / second.

  The heating member 103 is a prismatic thermal head, and adheres the glossy sheet to the surface of the toner image recording medium 2 by heating the glossy sheet 1 from the side of the substrate main body to be described later. Although the temperature of 160-200 degreeC is used as a temperature of the heating member 103, It is preferable that it is below the softening temperature of a glossy resin layer more than the softening temperature of a thermoadhesive resin layer.

  The pressing members 104a and 104b are cylindrical rollers that rotate about a rotation shaft whose surface is formed of elastic rubber, and press the glossy sheet adhered to the surface of the toner image recording medium 2 from above and below. The pressure applied by the pressure members 104a and 104b is preferably 1 kgf / cm 2 or more and 2 kgf / cm 2 or less, and the nip width formed by the pressure members 104a and 104b is preferably 0.5 mm or more and 2 mm or less.

  The cooling members 105a and 105b are made of an aluminum heat sink having a plurality of heat sinks, and cool the glossy sheet adhered to the surface of the toner image recording medium 2 from above and below. The width of the cooling members 105a and 105b is preferably equal to or greater than the paper width. Further, the shape of the cooling members 105a and 105b is substantially E-shaped with a cross section as shown in FIG. 2, but is not limited to this, and any shape having a high heat dissipation effect may be used.

  The base sheet peeling rollers 106a and 106b are cylindrical rollers that rotate about a rotation shaft whose surface is formed of elastic rubber, and peel the base sheet from the glossy sheet adhered to the surface of the toner image recording medium 2. As a result, a gloss image in which the transfer resin layer is adhered to the surface of the toner image recording medium 2 is generated and discharged to the outside of the thermal transfer apparatus 100.

  The base sheet collecting roller 107 is a cylindrical roller that rotates about a rotation axis, and collects the base sheet wound around a cylindrical peripheral surface.

  FIG. 3 is a cross-sectional view showing a configuration of the glossy sheet 1 used in the thermal transfer apparatus 100. The glossy sheet 1 imparts gloss to the toner image by transferring the transfer resin layer 20 onto the surface of the recording medium on which the toner image is formed using an electrophotographic image forming apparatus. The glossy sheet 1 is formed of a base sheet 14 and a transfer resin layer 20. The base sheet 14 includes a base body 12 and a release layer 13 formed on the surface of the base body 12 on the transfer resin layer 20 side. The transfer resin layer 20 includes a gloss resin layer 22 and a thermoadhesive resin layer 23 formed on the surface of the gloss resin layer 22 opposite to the base sheet 14.

  The base body 12 is a film-like resin material that carries the transfer resin layer 20 on its surface via a release layer 13. Examples of the substrate main body 12 include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone and other highly heat-resistant polyester, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, poly Plastic films such as vinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, and ionomer, and laminates thereof are used. The plastic film may be stretched or unstretched. The thickness of the substrate body 12 is appropriately selected in consideration of strength, heat resistance, flexibility, etc., but is usually about 1 to 100 μm.

  The release layer 13 is formed on the surface of the base body 12 for the purpose of smoothly peeling the base body 12 from the recording medium after the glossy sheet 1 is adhered to the recording medium on which the toner image is formed. The

  Examples of the resin constituting the release layer 13 include various waxes such as silicone wax, silicone resin, fluorine resin, acrylic resin, water-soluble resin, cellulose derivative resin, urethane resin, acetic acid vinyl resin, and acrylic vinyl ether resin. Various resins such as resins and maleic anhydride resins, and mixtures thereof can be used.

  The release layer 13 uses a gravure printing method, a screen printing method, or a gravure plate as a reverse coating liquid containing at least one selected from the group consisting of the waxes and the resin. It can form by apply | coating on the base-material main body 12 with normal coating methods, such as a roll coating method, and drying. In addition, the thickness of the release layer is preferably about 0.5 to 5.0 μm.

  The gloss resin layer 22 is a layer that becomes the outermost surface layer in the gloss image obtained after the base sheet 14 is peeled off from the state in which the gloss sheet 1 is adhered to the recording medium on which the toner image is formed. It is formed on the surface of the release layer 13 for the purpose of imparting gloss to the surface.

  The resin constituting the glossy resin layer 22 is composed of the same resin component as that constituting the binder resin of the color toner. In the present invention, the same resin component as the resin component constituting the binder resin of the color toner means that the raw material monomer of the resin component constituting the binder resin of the color toner is used as the raw material monomer of the resin component constituting the glossy resin layer 22. It means that the monomer is contained as a main component, that is, 80% or more by weight. Further, as the resin component constituting the gloss resin layer 22, it is more preferable to contain 90% by weight or more of the same resin component as the resin component contained in the binder resin of the color toner.

  The softening temperature of the resin component constituting the glossy resin layer 22 is preferably 50 degrees or more higher than the softening temperature of the thermal adhesive resin layer 23. Methods for increasing the softening temperature by 50 degrees or more include a method of adding a polymer having a weight average molecular weight of 100,000 or more, and a method of adding a crosslinking monomer such as a trivalent acid component such as trimellitic acid during the polymerization reaction.

  The gloss resin layer 22 is formed by a method of directly sticking as a film on the release layer 13 formed on the substrate body 12, or by dissolving or decomposing the thermoplastic resin and other additives in a solvent such as water or an organic solvent. Release ink formed on the substrate body 12 by a normal coating method such as gravure printing method, screen printing method, reverse roll coating method using gravure plate, etc. It is formed by applying on layer 13 and drying. The thickness of the gloss resin layer 22 is preferably about 1 to 20 μm in terms of flexibility and surface smoothness.

  The heat-adhesive resin layer 23 is a layer that directly adheres to the toner image when the glossy sheet 1 is adhered to the surface of the recording medium on which the toner image is formed, and the recording medium on which the toner image is formed and the glossy sheet 1. It is formed on the surface of the glossy resin layer 22 for the purpose of improving the adhesion.

  The resin constituting the heat-adhesive resin layer 23 is composed of the same resin component as that constituting the binder resin of the color toner. In the present invention, the same resin component as the resin component constituting the binder resin of the color toner means that the resin component constituting the binder resin of the color toner is used as a raw material monomer of the resin component constituting the thermal adhesive resin layer 23. It means that the raw material monomer is contained in the main component, that is, 80% or more by weight. Furthermore, the resin component constituting the heat-adhesive resin layer 23 more preferably contains 90% by weight or more of the same resin component as the resin component contained in the binder resin of the color toner.

  Further, the resin constituting the thermal adhesive resin layer 23 is preferably a thermoplastic resin having a glass transition temperature (Tg) of 50 to 80 ° C. The softening temperature is the softening of the binder resin of the color toner. It is preferable that it is below the temperature.

  The heat-adhesive resin layer 23 is a gravure printing method, a screen printing method, an ink obtained by dissolving or dispersing the above resin and other additives in a solvent such as water or an organic solvent. It forms by apply | coating on the glossy resin layer 22 and drying by normal coating methods, such as the reverse roll coating method using a gravure plate. The thickness of the heat adhesive resin is preferably 0.5 to 5 μm.

  The glossy sheet 1 can be obtained by pressing a jig provided with a stainless steel cylindrical projection on a stainless steel flat plate against a sheet on which these layers are laminated.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Glossy sheet 1 was prepared by the following procedure.

  First, a polyethylene terephthalate film manufactured by Toray Industries, Inc. having a width of 25 cm, a length of 1 m, and a thickness of 6 μm was used as the base body 12, and 16 parts by weight of a silicone-modified acrylic resin (cell top 226 solid content 50% by Daicel Chemical Industries ), 3 parts by weight of an aluminum catalyst (cell top CAT-A solid content 10%, manufactured by Daicel Chemical Industries, Ltd.), 8 parts by weight of methyl ethyl ketone, and 8 parts by weight of toluene. The release layer 13 was formed by applying and drying on the substrate main body 12 so that the ratio was 0.7 g / m 2.

  Next, an ink for a glossy resin layer having a composition of 40 parts by weight of an acrylic resin (BR-85 manufactured by Mitsubishi Rayon Co., Ltd.), 2 parts by weight of a polyester resin (Byron 200 manufactured by Toyobo Co., Ltd.), 50 parts by weight of methyl ethyl ketone, and 50 parts by weight of toluene, The glossy resin layer 22 was formed by applying and drying on the release layer 13 so that the film thickness after drying was 1 μm.

  Next, a methyl methacrylate-methacrylic acid copolymer (Tg: 70 ° C., SP value: 11.6) was synthesized, and the composition was 100 parts by weight of the copolymer, 50 parts by weight of methyl ethyl ketone, and 50 parts by weight of isopropyl alcohol. The ink for glossy resin layer was applied onto the glossy resin layer 22 by a gravure coating method so that the film thickness after drying was 1.5 μm and dried to form a heat-adhesive resin layer 23.

  Using a color multifunction machine (Sharp MX-5001FN), an A4 size toner image with 100% coverage was produced. As the medium, copy paper (PP116JA4 manufactured by Sharp) was used. As the color toner, a dedicated toner for a color multifunction machine was used.

  The gloss image was formed using the thermal transfer apparatus 100 as shown in FIG. 1 using the gloss sheet 1 produced above and the toner image. Glossy image formation conditions were a heating temperature (set value) of 200 ° C., a pressure of 1 kgf / cm2, a nip width of 1 mm, and a conveyance speed of 100 mm / second, and the glossiness of the obtained glossy image was measured.

  After the glossy sheet 1 is superimposed on the surface of the toner image recording medium, it is supplied to the heating member 103 and heated. Thereafter, pressure is applied by the pressure members 104a and 104b, and cooling is performed by the cooling members 105a and 105b. Here, even if the temperature is too high by the heating member 103, the base material sheet 14 is easily peeled off from the glossy resin layer 22 by artificially releasing the temperature by the cooling members 105 a and b. Unevenness is eliminated and a uniform gloss image can be obtained.

  In this example, when the surface temperature immediately after passing through the cooling members 105a and b was measured with a surface thermometer (IR-66B manufactured by MK Scientific Co., Ltd.), it was about 150 ° C., and the resin pulled a short thread. The temperature does not become (less than 180 ° C.). That is, even when the thermal transfer layer is heated to a temperature (180 ° C. or higher) at which many micron-order protrusions are formed on the surface of the thermal transfer layer by the heating member 103, it is more naturally cooled by the cooling members 105a and 105b. Since the temperature of the thermal transfer layer is lowered as soon as possible, when the base sheet 14 is peeled, the resin is lowered to a temperature (less than 180 ° C.) at which the short yarn is not pulled. Formation of micron-order protrusions can be prevented, and a uniform glossy image having no irregularities on the surface of the toner image can be obtained. Thus, the heating temperature control of the glossy sheet 1 is facilitated by using the cooling members 105a and 105b.

  The glossiness was measured by measuring 20 ° glossiness using a gloss meter VG2000 manufactured by Nippon Denshoku. The gloss unevenness evaluation method uses gloss for images having the same toner density, such as black, cyan, magenta, and yellow colors, or A4 size toner images with 100% coverage such as overlapping of two to three colors. An application process is performed and the glossiness of arbitrary 10 places is measured. As a result, it is determined that gloss unevenness can be suppressed if the entire image has a gloss level equal to or greater than a certain standard and the difference between the maximum and minimum gloss values is 10 or less.

  Further, it is determined that the occurrence of uneven gloss can be suppressed even in the case where there are no irregularities on the toner surface which are apparent in the visual evaluation, and there is no gloss imparting defect.

  As a result of measuring the glossiness of the glossy image obtained by the above method, the difference between the maximum value and the minimum value was small, and uniform glossiness was obtained over the entire image. In the thermal transfer apparatus 100, by providing the cooling members 105a and 105b, it was possible to suppress uneven gloss caused by unevenness of the surface of the transfer resin layer due to high supply energy.

(Comparative example)
As a comparative example, a gloss image was formed under the same conditions as in Example 1 except that no cooling member was used. As a result of measuring the glossiness of the obtained glossy image, the difference between the maximum value and the minimum value was large, and gloss unevenness was observed. The temperature at the peeling portion of the base material sheet 14 is about 190 ° C., and the temperature is not sufficiently lowered, and it is considered that the surface of the thermal transfer layer becomes uneven and uneven gloss occurs.

  Next, Example 2 will be described. FIG. 4 shows an example of another form of the cooling member. Here, the cooling members 105c and 105d are hollow, and the gloss sheet adhered to the surface of the toner image recording medium 2 through air or the like may be cooled in the vertical direction to enhance the cooling effect. .

  Next, Example 3 will be described. FIG. 5 shows an example in which an air blowing means is used as the cooling means. In this embodiment, a fan 105e as shown in the figure is used. The fan 105e is disposed in front of the base sheet peeling rollers 106a and 106b, and cools the glossy sheet adhered to the surface of the toner image recording medium 2 by applying air.

  As described above, by using the cooling means, it is possible to realize a glossy image forming apparatus that suppresses uneven glossiness at that portion even when the supply energy increases.

  The glossy image forming apparatus according to the present invention can be applied to a glossy image forming apparatus that forms a glossy image by attaching a glossy sheet to the surface of a toner image formed by using an electrophotographic method.

DESCRIPTION OF SYMBOLS 1 Glossy sheet 12 Base material main body 13 Release layer 14 Base material sheet 20 Transfer resin layer 22 Gloss resin layer 23 Thermal adhesive resin layer 50 Gloss image forming apparatus 100 Thermal transfer apparatus 101 Gloss sheet supply roller 102, 102a, b Recording medium supply Roller 103 Heating member 104a, b Pressure member 105a, b, c, d Cooling member 105e Fan 106, 106a, b Base sheet peeling roller 107 Base sheet collecting roller 200 Image forming apparatus

Claims (6)

A heating means for heating the transfer sheet in a state where the transfer resin layer of the glossy sheet having the base sheet and the transfer resin layer is in contact with the transfer target body;
A cooling means for cooling the glossy sheet heated and adhered to the surface of the transfer object;
A thermal transfer apparatus comprising: a peeling unit that peels the base sheet from the glossy sheet adhered to the surface of the transfer target.   The thermal transfer apparatus according to claim 1, wherein the cooling unit is a heat sink.   The thermal transfer apparatus according to claim 1, wherein the cooling means is a hollow metal member.   The thermal transfer apparatus according to claim 1, wherein the cooling unit is a blowing unit.   The thermal transfer apparatus according to claim 1, further comprising a pressurizing unit that applies pressure in a state where the transfer target and the glossy sheet are bonded.   A glossy image forming apparatus comprising the thermal transfer device according to claim 1.