Metallic paper, printed matter and image forming method

Abstract

To provide metallic paper that is excellent in adhesion to an image even when image formation is performed in an electrophotographic system.SOLUTION: Metallic paper for electrophotography contains polyester in its surface. The ratio of the following peak area B to the following peak area A (B / A) of an IR spectrum obtained by measuring the surface of the metallic paper by an ATR method (crystal: Ge, incident angle: 45°, single reflection) is 0.90 or less. [Peak] an area of the peak area A: 1709.586-1741.406 cm-1; an area of the peak area B: 1630.519-1670.052 cm-1; a base line: 1593.878-1850.364 cm-1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to metallic paper, a printed matter, and an image forming method. [Background technology]

[0002] In the field of printing, images printed on metallic-looking paper, so-called metallic paper (e.g., Patent Document 1), for the purpose of making printed matter stand out, are now seen on, for example, posters, book covers, packages, product tags, various cards, POP advertisements, display shelf fixtures, etc. These images have a very high impact and advertising effect because the non-image areas shine brightly or sparkle.

[0003] Images using metallic paper are often created using offset printing, but while offset printing is suitable for mass printing, it is not cost-effective for small-lot printing. Because the cost of metallic paper itself is high, there are more requests for small-lot printing of 100 sheets or less for images using metallic paper than for mass printing.

[0004] Electrophotographic image formation methods are one example of low-volume printing, but currently, image formation on metallic paper using electrophotography is rarely performed. One reason for this is the characteristics of images formed on metallic paper. When images are formed on metallic paper using only C (cyan), M (magenta), Y (yellow), and K (black), images with a large image area become dark and do not have impact. The solution to this is to place a white image at the bottom layer of the image, but since general electrophotographic image forming devices form images using four colors of toner, CMYK, it is not possible to print white at the bottom layer.

[0005] Meanwhile, recent industrial electrophotographic image forming devices are equipped with white toner in addition to the four colors of CMYK toner, and image formation using metallic paper images is now possible (e.g., Patent Document 2 and Patent Document 3). Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the prior art, there was no metallic paper that had excellent adhesion to images when used in electrophotographic systems. SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a metallic paper that has excellent adhesion to an image even when an image is formed on the metallic paper by electrophotography. [Means for solving the problem]

[0007] In order to solve the above problems, the electrophotographic metallic paper of the present invention is an electrophotographic metallic paper containing polyester on the surface, a layer having metallic luster is provided on a substrate, and a layer containing polyester is further provided thereon, the layer containing polyester is a polyester film, and the thickness of the layer containing polyester is 20 μm or more and 80 μm or less; The metallic paper is characterized in that the ratio B / A of the following peak area A to the following peak area B in the IR spectrum obtained by measuring the surface of the metallic paper by the ATR method (crystal: Ge, incident angle: 45°, single reflection) is 0.90 or less. [peak] Peak area A region: 1709.586~1741.406cm -1 Peak area B region: 1630.519~1670.052cm -1 Baseline: 1593.878~1850.364cm -1 Effect of the Invention

[0008] According to the present invention, it is possible to provide metallic paper that has excellent adhesion to images even when images are formed on the paper by electrophotography. [Brief description of the drawings]

[0009] [Figure 1] 1 shows examples of IR spectra of metallic paper, one included in the present invention (A) and one not included in the present invention (B). [Diagram 2] FIG. 2 is an enlarged view of a main part of FIG. [Diagram 3] FIG. 2 is an enlarged view of a main part of FIG. [Figure 4] FIG. 1 is a schematic explanatory diagram of an example of an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The metallic paper, printed matter, and image forming method according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and may be modified within the scope of what a person skilled in the art can imagine, such as other embodiments, additions, modifications, and deletions, and any embodiment is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0011] Metallic paper is generally made by laminating coated paper with a plastic film having a metal layer on one side, and polyester film has been used as the plastic film for metallic paper. On the other hand, polyester resin, styrene resin, etc. are generally used as binder resins for toner, and these binder resins are compatible with polyester, so if the toner is dissolved by applying sufficient heat, metallic paper should basically have good adhesion to the toner image.

[0012] However, even when electrophotographically forming an image on commercially available metallic paper, in most cases the adhesion between the metallic paper and the toner image is poor, and when the surface of the image is rubbed, the toner image is easily removed, making it very difficult to use. In particular, the more proven the metallic paper is in offset printing, the poorer the adhesion with the toner tends to be, and in the worst cases, the toner image peels off in a film-like manner just by applying vibration. In addition, with metallic paper with extremely poor adhesion, the toner image often peels off in a film-like manner even when the toner is sufficiently melted.

[0013] The inventor suspected that there might be some kind of layer on the surface of the metallic paper, and observed the cross section of metallic paper with extremely poor adhesion to toner using an electron microscope, but was unable to confirm any clear surface layer. The only information provided by the metallic paper manufacturers was that the outermost surface was polyester, but it seems that even the metallic paper manufacturers themselves are not clear about what kind of metallic paper is suitable for electrophotography.

[0014] The inventors obtained available metallic paper and performed electrophotographic image formation, and found that there was a small number of metallic papers on which it seemed possible to improve adhesion to toner images. Because the metallic paper in question was a minor variety, they obtained from a metallic paper manufacturer another variety of metallic paper using polyester on the surface and evaluated it, but did not obtain favorable results in terms of adhesion to toner images.

[0015] The inventor suspected that there might be some difference in the outermost surface of the metallic paper, and measured the IR spectrum of the surface of metallic paper that was likely to have improved adhesion to the toner image and that of metallic paper with poor adhesion by the ATR method (crystal: Ge, incident angle: 45°, one reflection). When both IR spectra were searched using the search function of OMNIC (manufactured by Thermo Fisher Scientific), an IR spectrum analysis software, polyester was found. Comparing the IR spectra in detail, the metallic paper with poor adhesion to the toner image had a peak at 1650 cm -1 It was found that there is a peak in

[0016] 1(A) and (B) show examples of the IR spectrum of metallic paper (A) with good adhesion to toner and metallic paper (B) with poor adhesion to toner. First, FIG. 1(B) showing the IR spectrum of metallic paper not included in the present invention will be described. As a result of intensive research, the present inventors have found that the IR spectrum of metallic paper with good adhesion to toner (A) is 1650 cm -1 When comparing the adhesion between metallic paper and toner images, the peak at 1650 cm -1It has been found that the smaller the peak, the more likely it is that the adhesion between the metallic paper and the toner image can be improved.

[0017] 1650cm -1 It is not clear why the peak exists at 1650 cm. -1 There is a reason why offset printing images tend to have a larger peak at 1650 cm. -1 It is highly likely that polyesters with this peak are distributed or manufactured as polyesters for metallic paper, and it is believed that there is some factor that causes the peak to appear when metallic paper is manufactured.

[0018] The inventors have repeatedly produced and verified metallic paper that can improve adhesion to toner images, and -1 The inventors have succeeded in producing metallic paper in which the peak at 1650 cm is sufficiently reduced. Figure 1(A) shows the IR spectrum of an example of metallic paper included in the present invention, which was produced by the inventors. -1 It was verified that the adhesion of the toner image to the metallic paper, in which the peak at 1650 cm is sufficiently reduced, is good. -1 The inventors have found that by quantifying the magnitude of the peak and specifying a preferred value, it is possible to provide metallic paper that is particularly suitable for use in electrophotography, and have arrived at the present invention.

[0019] That is, the electrophotographic metallic paper of the present invention is an electrophotographic metallic paper containing polyester on its surface, characterized in that the ratio B / A of the following peak area A to the following peak area B in the IR spectrum obtained by measuring the surface of the metallic paper by the ATR method (crystal: Ge, incident angle: 45°, single reflection) is 0.90 or less. [peak] Peak area A region: 1709.586~1741.406cm -1 Peak area B region: 1630.519~1670.052cm -1 Baseline: 1593.878~1850.364cm -1

[0020] The use of the metallic paper of the present invention is not particularly limited, but it is particularly suitable for use in electrophotography.

[0021] The peak area A represents an index of the metallic paper surface components that have good adhesion to the toner image, and the peak area B represents an index of the metallic paper surface components that have poor adhesion to the toner image. Therefore, the larger the ratio B / A, the worse the adhesion to the toner image, and the smaller the value, the better the adhesion to the toner image. In the present invention, the value of B / A is 0.90 or less, preferably 0.85 or less, and more preferably 0.60 or less.

[0022] Examples of IR spectra of an example of the metallic paper of the present invention are shown in Figures 2 and 3. Figures 2 and 3 are the same IR spectrum, and are enlarged views of a key portion of the IR spectrum of Figure 1. Figure 2 explains peak area A, and Figure 3 explains peak area B.

[0023] As shown in Figure 2, the area of ​​peak area A was calculated as 1709.586 cm -1 ~1741.406cm -1 As shown in Figure 3, the area of ​​peak area B is 1630.519 cm -1 ~1670.052cm -1 In addition, as shown in Figures 2 and 3, the baseline is set at 1593.878 cm -1 ~1850.364cm -1 It states that:

[0024] In the example shown here, the peak area A is calculated to be 3.065 from FIG. 2, and the peak area B is calculated to be 0.517 from FIG. 3. Therefore, B / A for the metallic paper in FIG. 1(A), FIG. 2, and FIG. 3 is 0.17. Similarly, when B / A is calculated for FIG. 1(B), it is 0.93. In FIG. 1(A) (FIG. 2, FIG. 3), where B / A satisfies the range of the present invention, the toner image has excellent adhesion, but in FIG. 1(B), where B / A does not satisfy the range of the present invention, the toner image has poor adhesion.

[0025] In order to bring B / A into the range of the present invention, that is, 0.90 or less, appropriate changes can be made. For example, the material of each layer in the metallic paper can be appropriately selected, and the thickness of the adhesive layer can be adjusted.

[0026] The electrophotographic metallic paper of the present invention is an electrophotographic metallic paper containing polyester on the surface. One example of the configuration is a configuration in which a layer having metallic luster is provided on a substrate, and a layer containing polyester (also called a polyester layer) is further provided on the layer. For example, a polyester film can be used as the layer containing polyester.

[0027] The metallic paper of the present invention can be produced, for example, by forming a layer having a metallic luster (also called a metallic luster layer) on a polyester film, laminating the polyester film on paper, and bonding the paper with an adhesive, with the surface on which the metallic luster layer is formed being the paper side.

[0028] The metallic luster layer may contain metals such as aluminum, silver, copper, gold, alloys, aluminum dyeing substances, organic metals, etc. From the viewpoint of cost, aluminum is preferably used, and when a colored metallic luster is desired, copper or gold is preferably used.

[0029] The metallic paper of the present invention has, for example, a polyester film on the surface, and the location where the metallic gloss layer is formed can be changed as appropriate, and the metallic gloss layer may be multiple. Since the metallic gloss layer has low electrical resistance, if it is located near the surface of the metallic paper, it is likely to cause discharge during transfer when forming an image by electrophotography, which may lead to a decrease in image quality and may be dangerous. Therefore, it is preferable that the metallic gloss layer is formed at a location somewhat away from the surface of the metallic paper.

[0030] In addition, when a metallic gloss layer is laminated on a polyester film by vapor deposition or sputtering, the metallic gloss layer has low mechanical strength, so it is preferable that the metallic gloss layer is located away from the surface of the metallic paper. From the standpoint of economy and the beauty of light reflection, it is preferable to laminate a metallic gloss layer on one side of a polyester film and bond the surface of the metallic gloss layer to paper to make metallic paper. In addition, since the metallic gloss layer has a higher thermal conductivity than other layers, it is preferable that the metallic gloss layer is located on the paper side of the polyester film in order to prevent the diffusion of heat on the metallic paper surface.

[0031] Considering the above, it is preferable that a metallic gloss layer is formed on a substrate such as paper, and a polyester film is further laminated thereon. The metallic gloss layer is preferably formed at a location 10 μm to 100 μm away from the surface of the metallic paper in the lamination direction, and more preferably at a location 12 μm to 90 μm away. If the location where the metallic gloss layer is formed is 10 μm or more inside the metallic paper surface, the possibility of discharge occurring during transfer can be reduced. If the location where the metallic gloss layer is formed is 100 μm or less away from the metallic paper surface, the beautiful metallic gloss can be prevented from being damaged.

[0032] The metallic gloss layer can be formed by, for example, a vacuum process using vapor deposition or sputtering, electroless plating, painting with metallic ink, adhesion of a metal or alloy film, etc. Among these, from the viewpoints of uniformity of the metallic gloss film and cost, it is preferable to use a vacuum process or painting with metallic ink.

[0033] The thickness of the metallic gloss layer can be appropriately selected depending on the metallic gloss and cost required for the metallic paper, but is preferably 0.02 to 2.00 μm, more preferably 0.03 to 1.00 μm, and even more preferably 0.03 to 0.50 μm. The metallic gloss layer is usually uniform in thickness, but the metallic gloss layer of the metallic paper may be patterned or formed into an arbitrary shape to change the thickness of the metallic gloss layer.

[0034] The thickness of the polyester-containing layer, for example, the polyester film, can be appropriately selected depending on the ease of handling, economic efficiency, and the required degree of metallic tone, but is preferably 10 to 100 μm, more preferably 12 to 100 μm, even more preferably 12 to 80 μm, and particularly preferably 20 to 80 μm. If it is 10 μm or more, it is easy to suppress discharge during the transfer process, and if it is 100 μm or less, it is possible to suppress the loss of light reflection and the increase in costs. In addition to the above advantages, if it is 10 to 100 μm, it is possible to suppress the difficulty of processing into metallic paper and prevent the difficulty of post-processing by folding, etc.

[0035] The metallic paper of the present invention has a polyester on the surface, which has good adhesion to the polyester or styrene acrylic contained in the toner matrix, and therefore a printed matter with good adhesion of the toner image can be obtained. In the present invention, an anchor coat layer may be provided for preventing static electricity and further improving adhesion. The thickness of the anchor coat layer is preferably 0.1 to 15.0 μm, more preferably 0.2 to 10.0 μm, and even more preferably 0.5 to 9.0 μm.

[0036] The metallic paper of the present invention is produced, for example, by bonding a polyester film having a metallic luster layer to paper with an adhesive. An adhesive having flexibility and adhesiveness can be used as the adhesive between the polyester film having a metallic luster layer and the paper. Examples of the adhesive include vinyl acetate, (ethylene-vinyl acetate copolymer resin), acrylic, etc. Considering the stability against heat, an acrylic adhesive is preferred.

[0037] The thickness of the adhesive layer is preferably 1 to 15 μm, and more preferably 2 to 10 μm. When the thickness is within the above range, it is possible to prevent the adhesive from becoming difficult to follow the unevenness of the paper surface and to prevent a decrease in adhesive strength. It is also possible to prevent an increase in cost and a decrease in the mechanical strength of the metallic paper. In addition, the thermal conductivity of the metallic paper is greatly affected by the thickness of the adhesive layer, and the thicker the adhesive layer, the more likely the thermal conductivity of the metallic paper is to decrease. Therefore, when the thickness of the adhesive is within the above range, it is easy to set the thermal conductivity of the metallic paper within the desired range and the adhesion of the toner is improved.

[0038] The paper (substrate) used for the metallic paper of the present invention may be plain paper, coated paper, etc., but considering the adhesiveness with the polyester film having a metallic gloss layer and the reflectance of the metallic paper, coated paper with a smooth surface is preferred. Considering the uses of the metallic paper, it is preferable for it to have a certain degree of thickness, so it is preferable to use coated paper with a basis weight of 100 to 350 GSM.

[0039] The thermal conductivity of the metallic paper of the present invention is preferably 0.34 W / m·K or less, and more preferably 0.23 to 0.33 W / m·K.

[0040] In general, in electrophotographic image formation, an unfixed toner image is transferred to one side of paper, and the unfixed toner image is passed between a heated fixing belt (fixing member) and a fixing counter roller (pressure member) facing it, with the unfixed toner image on the fixing belt side, to fix the toner image to the paper. Metallic paper is often thicker than ordinary paper, and when a white toner layer is formed at the bottom of the toner image, the toner image is thicker than a normal image. For this reason, if the thermal conductivity of metallic paper is high, the heat from the fixing belt may diffuse throughout the metallic paper, reducing the adhesion between the metallic paper surface and the toner. On the other hand, if the thermal conductivity of metallic paper is 0.34 W / m·K or less, the heat from the fixing belt is prevented from diffusing throughout the metallic paper, improving the adhesion of the toner image.

[0041] The thermal conductivity of the metallic paper of the present invention is measured by the hot wire method. The hot wire method is a simple measurement method, yet can measure the thermal conductivity of metallic paper with good reproducibility. The thermal conductivity of metallic paper is measured by the hot wire method of the present invention using a rapid thermal conductivity meter QTM-500 (manufactured by Kyoto Electronics Co., Ltd.) in an environment of 23±1°C and 50±5%. With the QTM-500, the metallic paper is placed with the metallic glossy side facing up on a reference plate with a known thermal conductivity, and the device probe is placed on the metallic paper to perform the measurement. The thermal conductivity can be obtained from the measurement results using quartz glass, silicone rubber, and silicone sponge rubber as reference plates.

[0042] In addition, the present invention provides a printed matter characterized in that a toner image is formed on the metallic paper of the present invention. The printed matter of the present invention has excellent toner adhesion and can form a beautiful metallic paper image.

[0043] The present invention also provides an image forming method using the metallic paper of the present invention. The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to a recording medium, and a fixing step of fixing the toner image transferred to the recording medium, the recording medium being the metallic paper of the present invention. According to the image forming method of the present invention, a beautiful metallic paper image can be created with excellent adhesion of the toner image.

[0044] In the image forming method of the present invention, it is preferable that a white toner image is formed as the bottom layer on metallic paper, and a color toner image is formed on the white toner image. That is, it is preferable that the developing step forms a white toner image and a color toner image, the transfer step transfers the white toner image on the metallic paper as the bottom layer, and the color toner image is positioned on the white toner image, and the fixing step passes the metallic paper between a heated fixing member and an opposing member opposing the fixing member, so that the surface on which the white toner image and the color toner image are transferred faces the fixing member, and the white toner image and the color toner image are fixed. In this case, the toner image has excellent adhesion, and a cleaner metallic paper image can be created.

[0045] Next, an example of an image forming apparatus used in the image forming method of the present invention will be described with reference to FIG.

[0046] <Image reading section> The image reading unit 11 generates image information by optically reading an image printed on a sheet of paper. Specifically, the image information is read by shining light on the sheet of paper and receiving the reflected light with a reading sensor such as a CCD (Charge Coupled Devices) or a CIS (Contact Image Sensor). Note that the image information is information representing an image to be formed on a recording medium such as paper, and is represented using electrical color separation image signals representing the colors red (R), green (G), and blue (B).

[0047] 4, the image reading unit 11 has a contact glass 111, a reading sensor 112, etc. A paper sheet having an image thereon is placed on the contact glass 111. The reading sensor 112 reads image information of the image written on the paper sheet placed on the contact glass 111.

[0048] <Image creation section> The image creating unit 12 forms an image (toner image) by adhering toner to the surface of the intermediate transfer belt 143 of the transfer unit 14 based on image information read by the image reading unit 11 or image information received via the network I / F.

[0049] The image forming section 12 includes an image forming unit 120C that forms a toner image using a developer having cyan (C) toner, an image forming unit 120M that forms a toner image using magenta (M) toner, an image forming unit 120Y that forms a toner image using yellow (Y) toner, an image forming unit 120K that forms a toner image using black (K) toner, and an image forming unit 120W that forms a toner image using white (W) toner.

[0050] In the following description, one or more of the C color toner, M color toner, Y color toner, and K color toner will be referred to as a color toner (also called a color toner or a process color toner). Each color toner contains a color material such as a pigment or a dye, and is, for example, a resin particle having an electrostatic property.

[0051] Moreover, the white toner is a toner containing a white pigment, for example, resin particles containing a white pigment and having electrostatic properties. Although not shown in FIG. 4, an imaging unit that forms a toner image using transparent clear toner and toner of a color other than CMYK may also be used.

[0052] Hereinafter, any one of image forming units 120C, 120M, 120Y, 120K, and 120W will be referred to as "image forming unit 120."

[0053] The image forming unit 120C includes a toner supplying section 121C, a photoconductor drum 122C, a charging section 123C, an exposure section 124C, a developing section 125C, a charge removing section 126C, and a cleaning section 127C.

[0054] The toner supply unit 121C contains C-color toner and supplies the C-color toner to the developing unit 125C. A predetermined amount of the toner contained in the toner supply unit 121C is supplied to the developing unit 125C by driving a conveying screw in the toner supply unit 121C. The toner supply unit 121C may be referred to as a developer container 121C.

[0055] The surface of the photoconductor drum 122C is uniformly charged by the charging section 123C, and an electrostatic latent image is formed on the surface by the exposure section 124C based on image information received from the control section 10. A toner image is formed on the surface of the photoconductor drum 122C by the developing section 125C attaching toner to the surface on which the electrostatic latent image is formed. The photoconductor drum 122C is provided so as to be in contact with the intermediate transfer belt 143, and is provided so as to rotate in the same direction as the movement direction of the intermediate transfer belt 143 at the point of contact with the intermediate transfer belt 143.

[0056] The charging section 123C uniformly charges the surface of the photoconductor drum 122C. The exposure section 124C irradiates the surface of the photoconductor drum 122C, which has been charged by the charging section 123C, with light based on the C color dot area ratio determined by the control section 10, to form an electrostatic latent image.

[0057] The developing unit 125C develops the electrostatic latent image formed on the surface of the photoconductor drum 122C by the exposure unit 124C by applying C-color toner contained in the developer container 121C to the electrostatic latent image, thereby forming a toner image.

[0058] The charge removing section 126C removes charge from the surface of the photoconductor drum 122C after the image has been transferred to the intermediate transfer belt 143. The cleaning section 127C removes the residual toner remaining on the surface of the photoconductor drum 122C that has been removed by the charge removing section 126C.

[0059] Image forming unit 120M includes developer container 121M, photoconductor drum 122M, charging section 123M, exposure section 124M, development section 125M, charge removal section 126M, and cleaning section 127M. Developer container 121M contains M color toner. Photoconductor drum 122M, charging section 123M, exposure section 124M, development section 125M, charge removal section 126M, and cleaning section 127M have the same functions as photoconductor drum 122C, charging section 123C, exposure section 124C, development section 125C, charge removal section 126C, and cleaning section 127C, respectively, and therefore their description will be omitted.

[0060] The image forming unit 120Y includes a developer container 121Y, a photoconductor drum 122Y, a charging section 123Y, an exposure section 124Y, a developing section 125Y, a charge removing section 126Y, and a cleaning section 127Y. The developer container 121Y contains Y-color toner. The photoconductor drum 122Y, the charging section 123Y, the exposure section 124Y, the developing section 125Y, the charge removing section 126Y, and the cleaning section 127Y have the same functions as the photoconductor drum 122C, the charging section 123C, the exposure section 124C, the developing section 125C, the charge removing section 126C, and the cleaning section 127C, respectively, and therefore their description will be omitted.

[0061] The image forming unit 120K includes a developer container 121K, a photoconductor drum 122K, a charging unit 123K, an exposure unit 124K, a developing unit 125K, a charge removing unit 126K, and a cleaning unit 127K. The developer container 121K contains K color toner. The photoconductor drum 122K, the charging unit 123K, the exposure unit 124K, the developing unit 125K, the charge removing unit 126K, and the cleaning unit 127K have the same functions as the photoconductor drum 122C, the charging unit 123C, the exposure unit 124C, the developing unit 125C, the charge removing unit 126C, and the cleaning unit 127C, respectively, and therefore their description will be omitted.

[0062] Image forming unit 120W includes developer container 121W, photoconductor drum 122W, charging section 123W, exposure section 124W, development section 125W, charge removal section 126W, and cleaning section 127W. Developer container 121W contains white toner. Photoconductor drum 122W, charging section 123W, exposure section 124W, development section 125W, charge removal section 126W, and cleaning section 127W have the same functions as photoconductor drum 122C, charging section 123C, exposure section 124C, development section 125C, charge removal section 126C, and cleaning section 127C, respectively, and therefore their description will be omitted.

[0063] In the following description, any one of the developer containers 121C, 121M, 121Y, 121K, and 121W will be referred to as "developer container 121." Further, any one of the photoconductor drums 122C, 122M, 122Y, 122K, and 122W will be referred to as "photoconductor drum 122." Further, any one of the charging section 123C, the charging section 123M, the charging section 123Y, the charging section 123K, and the charging section 123W will be referred to as "the charging section 123". Further, any one of exposure sections 124C, 124M, 124Y, 124K, and 124W will be referred to as "exposure section 124". Further, any one of developing units 125C, 125M, 125Y, 125K, and 125W will be referred to as "developing unit 125." Further, any one of the charge eliminating units 126C, 126M, 126Y, 126K, and 126W will be referred to as "charge eliminating unit 126." Additionally, any one of cleaning unit 127C, cleaning unit 127M, cleaning unit 127Y, cleaning unit 127K, and cleaning unit 127W will be referred to as "cleaning unit 127."

[0064] The order of the toners transferred onto the intermediate transfer belt 143 is such that the white toner is transferred last, and the order of the CMYK toners other than the white toner does not matter. That is, the image forming unit 120W is disposed at the most downstream position.

[0065] <Paper feed section> The paper feed unit 13 supplies paper to the transfer unit 14. The paper feed unit 13 includes a paper storage unit 131, a paper feed roller 132, a paper feed belt 133, and registration rollers 134.

[0066] Paper storage section 131 stores paper, which is an example of a recording medium. Paper feed roller 132 is provided to rotate in order to move the paper stored in paper storage section 131 toward the paper feed belt. Paper feed roller 132 thus provided takes out the topmost paper sheets from among the stored paper sheets one by one and places them on the paper feed belt.

[0067] The paper feed belt 133 conveys the paper picked up by the paper feed roller 132 to the transfer unit 14. The registration rollers 134 send out the paper conveyed by the paper feed belt 133 at the timing when a portion of the intermediate transfer belt 143, which will be described later, on which a toner image is formed, reaches the transfer unit 14.

[0068] <Transfer section> The transfer unit 14 transfers the image formed on the photoconductor drum 122 by the image creating unit 12 onto the intermediate transfer belt 143 (primary transfer), and transfers the image transferred onto the intermediate transfer belt 143 onto paper (secondary transfer).

[0069] The transfer unit 14 includes a drive roller 141, a driven roller 142, an intermediate transfer belt 143, primary transfer rollers 144C, 144M, 144Y, 144K, and 144W, a secondary transfer roller 145, and a secondary opposing roller 146.

[0070] The driving roller 141 and the driven roller 142 are arranged to hold the intermediate transfer belt 143. The driving roller 141 is driven and rotated, whereby the intermediate transfer belt 143 moves. The driven roller 142 and the driving roller 141 are arranged to hold the intermediate transfer belt 143. The driven roller 142 rotates as the driving roller 141 rotates and the intermediate transfer belt 143 moves.

[0071] The intermediate transfer belt 143 is stretched around a drive roller 141 and a driven roller 142, and moves in contact with the photosensitive drum 122 as the drive roller 141 rotates. As the intermediate transfer belt 143 moves in contact with the photosensitive drum 122, an image formed on the photosensitive drum 122 is transferred onto the surface of the intermediate transfer belt 143.

[0072] Primary transfer rollers 144C, 144M, 144Y, 144K, and 144W are provided facing photoconductor drums 122C, 122M, 122Y, 122K, and 122W, respectively, with intermediate transfer belt 143 interposed therebetween, and rotate to move intermediate transfer belt 143.

[0073] The secondary transfer roller 145 rotates with the intermediate transfer belt 143 and the paper sandwiched between it and the secondary opposing roller 146. The secondary opposing roller 146 rotates with the intermediate transfer belt 143 and the paper sandwiched between it and the secondary transfer roller 145.

[0074] When producing a printed matter in which a color toner image is formed on a white toner image, the white toner image is placed as the bottom layer on metallic paper, and the color toner images are transferred onto the white toner image.

[0075] <Fixing section> The fixing unit 15 fixes the toner transferred to the paper by the transfer unit 14. Fixing refers to fusing the resin component of the toner to the paper by simultaneously applying heat and pressure to the toner. By performing the fixing process on the toner transferred to the paper by the transfer unit 14, the state of the toner on the paper becomes stable.

[0076] The fixing unit 15 has a conveyor belt 151, a fixing belt 152, a fixing roller 153, a fixing belt conveyor roller 154, a fixing opposing roller 155, and a heat generating unit 156. The fixing belt 152 and the fixing roller 153 are examples of the fixing member described above, and the fixing opposing roller 155 is an example of the opposing member described above.

[0077] Conveyor belt 151 conveys the paper onto which the toner has been transferred by transfer unit 14 toward fixing roller 153 and fixing counter roller 155. Fixing belt 152 is stretched across fixing roller 153 and fixing belt conveyor roller 154, and moves as these rollers rotate. Fixing roller 153 sandwiches the paper conveyed to conveyor belt 151 between itself and fixing counter roller 155, which is disposed opposite it, and applies heat and pressure to the paper.

[0078] The fixing belt conveying roller 154, together with the fixing roller 153, stretches the fixing belt 152, and the rotation of the fixing belt conveying roller 154 moves the fixing belt 152. The fixing opposing roller 155 is disposed opposite the fixing roller 153, and sandwiches the conveyed paper between the fixing roller 153 and itself.

[0079] Heat generating unit 156 is disposed inside transport roller 154 and generates heat. Heat generated by heat generating unit 156 increases the temperature of transport roller 154 and heats fixing belt 152. The heated fixing belt rotates to heat the paper.

[0080] 4, heat generating unit 156 is installed inside conveying roller 154, but it may be located anywhere as long as it can heat fixing belt 152. For example, if an IH heater (induction heater) is used as heat generating unit 156, it may be located outside conveying roller 154 and fixing belt 152. Also, it is possible to use only fixing roller 153 with heat generating unit 156 located inside without using fixing belt 152. Also, a heat generating unit may be located inside or outside fixing counter roller 155.

[0081] When producing a printed matter in which a color toner image is formed on a white toner image, a metallic paper is passed between the fixing belt 152 and the fixing opposing roller 155 so that the surface onto which the white toner image and the color toner image are transferred faces the fixing belt 152, and the white toner image and the color toner image are fixed.

[0082] <Paper ejection section> The paper discharge section 16 discharges the paper onto which the toner has been fixed by the fixing section 15 from the image forming apparatus 1 , and includes a paper discharge belt 161 , a paper discharge roller 162 , a paper discharge port 163 , and a paper storage section 164 .

[0083] The paper discharge belt 161 transports the paper that has been fixed by the fixing unit 15 toward the paper discharge port 163. The paper discharge rollers 162 discharge the paper transported by the paper discharge belt 161 from the paper discharge port 163 and store the paper in the paper storage unit 164. The paper storage unit 164 stores the paper discharged by the paper discharge rollers 162.

[0084] <Display / operation section> The display / operation unit 17 has a panel display unit 171 and an operation unit 172. Setting values, selection screens, etc. are displayed on the panel display unit 171. The panel display unit 171 is a touch panel or the like that receives input from an operator. The operation unit 172 is operated by the user to input, such as a numeric keypad that receives various conditions related to image formation, a start key that receives a copy start instruction, etc. EXAMPLES

[0085] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0086] (Example 1, Comparative Example 1) A toner image was formed on metallic paper (SP-714 (Gojo Paper Co., Ltd.)) with a polyester surface. When the metallic paper surface was measured using the ATR method (crystal: Ge, incident angle: 45°, one reflection), the IR spectrum shown in Figure 1(A) was obtained, and the B / A ratio was 0.17. A toner image was also formed on metallic paper with a polyester surface (SP-730 (manufactured by Gojo Paper Co., Ltd.)). When this metallic paper was measured using the ATR method, the IR spectrum shown in Figure 1(B) was obtained, and the B / A ratio was 0.93. The thermal conductivity of each metallic paper was measured with a QTM-500 rapid thermal conductivity meter (Kyoto Electronics Manufacturing Co., Ltd.) in an environment of 23±1°C and 50±5% humidity, with the metallic glossy side facing up. Quartz glass, silicone rubber, and silicone sponge rubber were used as reference plates. The thermal conductivity of the metallic papers in Example 1 and Comparative Example 1 was 0.245 W / m K and 0.341 W / m K, respectively. The layer structure of each metallic paper was as shown in Table 1. The layer structure of the metallic paper was determined by preparing a cross section of the metallic paper using an IB-19520CCP cross section sample preparation device (manufactured by JEOL Ltd.), and measuring the thickness of each layer using an electron microscope.

[0087] Next, a toner image was formed on each of the metallic papers. A modified color production printer Pro C7200S (manufactured by Ricoh) was used as the image forming device. Normally, when attempting to form an image on thick paper such as metallic paper, the paper sensor of the Pro C7200S is activated, slowing down the print speed and increasing the amount of heat supplied to the toner image (medium speed mode). On the other hand, the modified Pro C7200S was modified to block the signal from the paper sensor so that printing can be performed at the normal print speed even when forming an image on metallic paper (high speed mode). The image to be formed was an image in which a white solid image and a magenta solid image were superimposed. A white solid image was formed on metallic paper, and a magenta solid image was further formed on the white solid image. In this way, a printed matter in which a toner image was formed on metallic paper was obtained.

[0088] Next, the toner adhesiveness was evaluated. The toner adhesiveness was evaluated using a drawing tester (Ueshima Seisakusho, AD-2110). The load of the drawing tester was set to 50 g, the moving stage was fixed, and the same spot was rubbed 100 times, after which the state of toner peeling was visually observed, and the visual observation result was used as the evaluation result of fixability. The evaluation criteria are as follows: ◎ is very good (practical level), ○ is good (practical level), △ is poor (NG level), and × is very poor (NG level).

[0089] [Evaluation Criteria] ◎: No toner peeling ○: A small amount of toner peeling is observed, but the metallic paper is not exposed. △: Metallic paper is exposed in some areas. ×: The image has peeled off like a film, and the metallic paper is completely exposed.

[0090] The metallic paper of Example 1, which had a B / A ratio of 0.17, had excellent adhesion to the toner and produced very clear images, whereas the metallic paper of Comparative Example 1, which had a B / A ratio of 0.93, had some areas where adhesion to the toner was somewhat weak.

[0091] Next, the signal from the paper sensor was normalized, and an image was formed by superimposing a white solid image, a cyan solid image, a magenta solid image, a yellow solid image, and a black solid image. As a result, the metallic paper of Example 1, which has a B / A of 0.17, had excellent adhesion to the toner, and a very beautiful image was obtained. On the other hand, the metallic paper of Comparative Example 1, which has a B / A of 0.93, easily peeled off when the surface of the toner image was rubbed.

[0092] (Examples 2 to 4, Comparative Example 2) Using the metallic papers shown in Table 1, a toner image was formed on each metallic paper, and the adhesion between the toner image and the metallic paper was evaluated in the same manner as in Example 1. The results are shown in Table 1. The adhesion evaluation results in Table 1 are, as described above, evaluations when an image was formed by overlapping a solid white image, a solid cyan image, a solid magenta image, a solid yellow image, and a solid black image, and images were formed in both medium speed mode and high speed mode, and evaluations were performed in each mode.

[0093] [Table 1]

[0094] As described above, according to this embodiment, it is possible to obtain metallic paper having excellent adhesion to an image even when an image is formed by electrophotography. [Explanation of symbols]

[0095] 10 Control section 11 Image reading unit 111 Contact Glass 112 Reading sensor 12 Imaging section 120 Image forming unit 121 Toner supply unit 122 Photoconductor drum 123 Charging section 124 Exposure section 125 Development Unit 126 Static electricity removal unit 127 Cleaning Department 14 Transcription section 143 Intermediate transfer belt 144 Primary transfer roller 145 Secondary transfer roller 146 Secondary opposing roller 13 Paper feed section 131 Paper storage section 132 Paper feed roller 133 Paper feed belt 134 Registration roller 15 Fixing section 151 Conveyor Belt 152 Fixing belt 153 Fuser roller 154 Fixing belt transport roller 155 Fuser facing roller 156 Heat generating part 16 Paper ejection section 161 Paper output belt 162 Paper ejection roller 163 Paper output port 164 Paper storage section 17 Display / operation section 171 Panel display 172 Operation section [Prior art documents] [Patent documents]

[0096] [Patent Document 1] Japanese Patent Application Publication No. 61-215793 [Patent Document 2] JP 2016-021037 A [Patent Document 3] JP 2016-139001 A

Claims

1. A metallic paper for electrophotography containing polyester on the surface, A layer having a metallic luster is provided on a substrate, and a layer containing polyester is further provided thereon; the polyester-containing layer is a polyester film, The thickness of the polyester-containing layer is 20 μm or more and 80 μm or less, The electrophotographic metallic paper is characterized in that the ratio B / A of the following peak area A to the following peak area B in the IR spectrum obtained by measuring the surface of the metallic paper by the ATR method (crystal: Ge, incident angle: 45°, single reflection) is 0.90 or less. [peak] Peak area A region: 1709.586 to 1741.406 cm －１ Peak area B region: 1630.519 to 1670.052 cm －１ Baseline: 1593.878-1850.364 cm －１

2. 2. The electrophotographic metallic paper according to claim 1, wherein the thermal conductivity by a hot wire method is 0.34 W / m·K or less.

3. 3. The electrophotographic metallic paper according to claim 1, wherein the layer having metallic luster is formed at a position 10 [mu]m to 100 [mu]m deep from the surface of the metallic paper in the lamination direction.

4. the layer having metallic luster is provided on the base material via an adhesive layer, 4. The electrophotographic metallic paper according to claim 1, wherein the adhesive layer has a thickness of 1 μm or more and 15 μm or less.

5. A printed matter comprising a toner image formed on the electrophotographic metallic paper according to any one of claims 1 to 4.

6. an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier; a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with a toner to form a toner image; a transfer step of transferring the toner image formed on the electrostatic latent image carrier onto a recording medium; A fixing step of fixing the toner image transferred onto the recording medium, 5. An image forming method, comprising the step of: recording the recording medium comprising the electrophotographic metallic paper according to claim 1.

7. The developing step forms a white toner image and a color toner image, In the transfer step, the white toner image is transferred onto the metallic paper in such a manner that the white toner image is the bottom layer, and the color toner image is positioned on the white toner image.

7. The image forming method according to claim 6, wherein the fixing step includes passing the metallic paper between a heated fixing member and an opposing member opposed to the fixing member so that the surface onto which the white toner image and the color toner image are transferred faces the fixing member, thereby fixing the white toner image and the color toner image.

Images