Method for manufacturing processed media, manufacturing apparatus, and manufacturing system

Abstract

This provides a novel technology that can suppress beading. [Solution] A manufacturing method for producing a processed medium by performing a process on the medium, wherein the medium is a cardboard sheet having a coating layer containing a binder on its surface, and the manufacturing method comprises a heating step of heating the medium, and an adhesion step of applying ink to the coating layer after the heating step. In the heating step, the medium is heated such that when the heating temperature is X [°C] and the heating time is Y [minutes], the relationship X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0) is satisfied.

Description

[Technical Field]

[0001] This specification discloses a manufacturing method, manufacturing apparatus, and manufacturing system for producing a processed medium by performing a process on the medium. [Background technology]

[0002] Patent Document 1 discloses a pre-coating liquid applied to the surface of a medium. Patent Document 1 states that by applying this pre-coating liquid to the surface of the medium, beading of the ink subsequently applied to the medium can be suppressed. Beading refers to the phenomenon in which, when ink is fixed on a medium, adjacent dots attract each other due to surface tension and aggregate into a bead-like shape. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-39058 Public Relations [Overview of the project] [Problems that the invention aims to solve]

[0004] This specification provides a novel technology that can suppress ink beading. [Means for solving the problem]

[0005] This specification discloses a manufacturing method for producing a processed medium by performing a process on the medium. The medium is a cardboard having a coating layer containing a binder on its surface. The manufacturing method comprises a heating step of heating the medium and an adhesion step of applying ink to the coating layer after the heating step. In the heating step, the medium is heated such that the heating temperature is X [°C] and the heating time is Y [minutes], satisfying the relationship X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0).

[0006] When numerous fine irregularities exist on the surface of the medium, adjacent dots tend to aggregate, making beading more likely. In the manufacturing method described above, the medium is heated in the heating step under conditions that satisfy the above relationship. In other words, in the manufacturing method described above, higher energy is applied to the medium in the heating step than in the various treatments generally performed on the medium. The surface of the medium is provided with a coating layer containing a binder. Therefore, by performing the heating step, the binder contained in the coating layer softens, and the surface of the coating layer is smoothed. As a result, when ink is applied to the surface of the coating layer in the adhesion step, the wettability of the ink improves, and the ink adheres more uniformly to the surface of the coating layer. Consequently, it is believed that ink beading can be suppressed in the manufacturing method described above.

[0007] Furthermore, a novel and useful manufacturing apparatus is also available that performs processing on a medium to produce a processed medium. The medium is a cardboard sheet having a coating layer containing a binder on its surface. The manufacturing apparatus comprises a heating device for heating the medium and an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device. The heating device heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0).

[0008] Furthermore, a novel and useful manufacturing system is also provided for producing a processed medium by performing a process on the medium. The medium is a cardboard sheet having a coating layer containing a binder on its surface. The manufacturing system comprises a heating device for heating the medium and an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device. The heating device heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], the relationship X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0) is satisfied. [Brief explanation of the drawing]

[0009] [Figure 1]The configuration of the surface treatment system is shown. [Figure 2] A graph illustrating the relationship between the heating temperature and heating time of the medium is shown. [Figure 3] A magnified view of a portion of Figure 2 is shown. [Figure 4] A graph illustrating an example of the relationship between the heating temperature and heating time of a medium is shown. [Modes for carrying out the invention]

[0010] (Configuration of surface treatment system 10) An embodiment of the surface treatment system 10 will be described with reference to the drawings. As shown in Figure 1, the surface treatment system 10 comprises a heating device 30 and an adhesion device 40. The surface treatment system 10 produces a treated medium 2 by heating the medium 2 and then adhering ink to the medium 2. By heating the medium 2, the physical properties of the surface of the medium 2 are modified, and ink beading is suppressed. The heating device 30 and the adhesion device 40 are used by being placed on the floor or on a rack. However, in other embodiments, the heating device 30 and the adhesion device 40 may be used by being placed on a tabletop.

[0011] The surface treatment system 10 comprises a supply tray 14, a supply roller 16, a conveying device 18, a discharge tray 24, and a control unit 26. The control unit 26 is communicated with each part of the surface treatment system 10. This allows the control unit 26 to control the operation of each part of the surface treatment system 10.

[0012] The supply tray 14 is detachably supported in the housing 31 of the heating device 30. The supply tray 14 supports the medium 2. The user can expose the supply tray 14 to the outside of the housing 31 and stack multiple media 2 inside the supply tray 14. Then, when the supply tray 14 is housed inside the housing 31, the medium 2 is supplied to the surface treatment system 10.

[0013] The supply roller 16 comes into contact with the top surface of the uppermost medium 2 among the plurality of media 2 supported by the supply tray 14. The supply roller 16 is rotated by a conveyance motor. As the supply roller 16 rotates, the uppermost medium 2 is taken out from the supply tray 14.

[0014] The conveyance device 18 is disposed extending from the inside of the housing 31 of the heating device 30 to the inside of the housing 41 of the deposition device 40. The conveyance device 18 conveys the medium 2 supplied from the supply roller 16 to the discharge tray 24. The conveyance device 18 includes two first roller pairs 20 and two second roller pairs 22.

[0015] Each of the two first roller pairs 20 is disposed inside the housing 31 of the heating device 30. Each of the two first roller pairs 20 includes a first conveyance roller 20a and a first pinch roller 20b. The first conveyance roller 20a abuts against the first pinch roller 20b to form a nip 4. Each of the two first roller pairs 20 is rotated by the conveyance motor. Each of the two first roller pairs 20 conveys the medium 2 sent out from the supply roller 16 to the second roller pair 22 by rotating while nipping the medium 2. The number and arrangement of the first roller pairs 20 are not particularly limited.

[0016] Each of the two second roller pairs 22 is disposed inside the housing 41 of the deposition device 40. Each of the two second roller pairs 22 includes a second conveyance roller 22a and a second pinch roller 22b. The second conveyance roller 22a abuts against the second pinch roller 22b to form a nip 4. Each of the two second roller pairs 22 is rotated by the conveyance motor. Each of the two second roller pairs 22 conveys the medium 2 to the discharge tray 24 by rotating while nipping the medium 2. The number and arrangement of the second roller pairs 22 are not particularly limited.

[0017] The discharge tray 24 is disposed inside the housing 41 of the deposition device 40. The medium 2 is discharged from the conveyance device 18 to the discharge tray 24. The discharge tray 24 supports the medium 2.

[0018] Between the supply tray 14 and the discharge tray 24, a transport path 100 is formed, spanning from the heating device 30 to the adhesion device 40, through which the medium 2 is transported. As the medium 2 passes through this transport path 100, it is heated, and then ink is applied to the medium 2.

[0019] The heating device 30 comprises a heating unit 32 and a control unit 34. The heating unit 32 is positioned above the transport path 100. The heating unit 32 is composed of, for example, a dryer, a heat gun, an oven, an IR heater, etc. The control unit 34 controls the operation of the heating unit 32 based on commands from the control unit 26. By controlling the heating unit 32, the control unit 34 heats the medium 2 under conditions that satisfy a predetermined relationship between heating temperature and heating time. These conditions will be described later. The specific configuration of the heating device 30 is not particularly limited. In this embodiment, the heating unit 32 is positioned above the transport path 100, but the heating unit 32 may be positioned below the transport path 100, or both above and below the transport path 100. Furthermore, the heating unit 32 may be positioned so that the transport path 100 passes through the inside of the heating unit 32.

[0020] The adhesion device 40 is located downstream of the heating device 30 in the transport path 100. The adhesion device 40 comprises a head 42 and a control unit 44. The head 42 is located above the transport path 100. The head 42 is equipped with a plurality of nozzles 42a. The control unit 44 controls the operation of the head 42 based on commands from the control unit 26. The control unit 44 controls a piezoelectric element, etc., corresponding to each nozzle 42a. By controlling the piezoelectric element, etc., the control unit 44 selectively ejects ink to the outside through each nozzle 42a using an inkjet method. In this way, ink is selectively ejected from each nozzle 42a toward the medium 2 passing through the transport path 100, thereby adhering the ink to the surface of the medium 2. The specific configuration of the adhesion device 40 is not particularly limited.

[0021] Note that the components of the surface treatment system 10 do not necessarily have to be located in the positions shown in the figure. For example, the supply tray 14 may be provided outside the housing 31 of the heating device 30, and the discharge tray 24 may be provided outside the housing 41 of the adhesion device 40. The first roller pair 20 and the second roller pair 22 may also be provided outside the housings 31 and 41, respectively.

[0022] (medium) Medium 2 is a cardboard sheet with a coating layer on its surface. Medium 2 may be white cardboard or colored cardboard. Medium 2 has a base material and a coating layer.

[0023] (base material) The base material is composed of a paper material with pulp as a component. The paper material may be multi-layered or single-layered. The thickness of the base material is not particularly limited. For example, the thickness may be 0.2 mm to 0.6 mm or 0.3 mm to 0.5 mm. In other words, the base material of medium 2 has a relatively large thickness, and so-called ordinary paper and thin paper are not included in the base material.

[0024] (Coat layer) The coating layer is provided on the surface of the substrate. The coating layer is provided, for example, on the surface of a substrate made of paper material to impart smoothness and gloss. The coating layer is also provided, for example, to improve the barrier properties and durability of the medium 2 against moisture and oil. As a result, the ink adheres well to the medium 2, ink unevenness is suppressed, and the printability of the medium 2 is improved. The thickness of the coating layer is not particularly limited, but for example, it is 1 μm to 20 μm, or 3 μm to 15 μm.

[0025] The coating layer contains a binder. The binder is not particularly limited, but examples include styrene-butadiene resins; acrylic resins such as methyl (meth)acrylate copolymers and styrene-(meth)acrylic copolymers; olefin-unsaturated carboxylic acid copolymers such as ethylene-(meth)acrylic acid copolymers; natural polysaccharides and their oligomers and modified forms such as dextrin, mannan, chitosan, arabinogalactan, glycogen, inulin, pectin, hyaluronic acid, hydroxyethylated starch, oxidized starch, etherified starch, phosphate-esterified starch, enzyme-modified starch, and modified starch obtained by flash-drying these. These binders may be used individually or in combination of two or more types.

[0026] The coating layer may contain pigments. Examples of pigments, though not particularly limited, include inorganic pigments such as kaolin, clay, engineered kaolin, delaminated clay, calcined clay, heavy calcium carbonate, light calcium carbonate, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicates, colloidal silica, and satin white; and organic pigments such as solid, hollow, or core-shell types.

[0027] The coating layer may also contain other components such as adhesives, dispersants, thickeners, water-retaining agents, defoaming agents, water-resistant agents, colorants, and surfactants. Examples of adhesives include proteins such as casein, soy protein, and synthetic protein; starches such as oxidized starch, positive starch, urea phosphate esterified starch, hydroxyethyl etherified starch, and dextrin; and cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, and hydroxymethylcellulose.

[0028] (Surface free energy of the coating layer) After the medium 2 is heat-treated by the heating device 30 of the surface treatment system 10, ink is applied to the surface of the coating layer. To improve the wettability and adhesion of the ink to the coating layer, a higher surface free energy of the coating layer is preferable. The surface free energy of the coating layer is not particularly limited, but may be, for example, 30 [mN / m] or more, 40 [mN / m] or more, 45 [mN / m] or more, 47 [mN / m] or more, or 50 [mN / m] or more. When the surface free energy of the coating layer satisfies the above values, ink beading can be suitably suppressed by applying the technology disclosed herein.

[0029] The method for controlling the surface free energy of the coating layer to the above-mentioned value is not particularly limited. Examples of such methods include: changing the contact angle by selecting the type of binder to be included; changing the contact angle by physically altering the microstructure of the surface; changing the contact angle by introducing functional groups to the surface through physicochemical treatments such as heat, light, electromagnetic waves, oxidation, and reduction; and changing the contact angle by altering the surface properties by including surface treatment agents such as surfactants or chemical components such as coupling agents. The surface free energy of the coating layer can be measured in accordance with JIS K6768:1999.

[0030] (Climb density of the court layer, Spd) Spd represents the number of peaks per unit area as defined by ISO 25178. The surface of the coating layer is smoother than the surface of the substrate. However, the surface of the coating layer also has fine irregularities. Therefore, if there are many peaks due to the irregularities, the ink adhering to the surface of the coating layer is easily guided into the valleys between the peaks, making beading more likely to occur. In the technology disclosed herein, the Spd of the coating layer can be reduced by performing a heat treatment on the medium 2 using the heating device 30 of the surface treatment system 10. Since the coating layer contains a binder, when the heat treatment is performed, the binder contained in the coating layer softens and the surface of the coating layer is smoothed. The coating layer of the medium 2 may be made of a material in which the Spd is reduced by 10% or more compared to before heating when heated at 150°C for 60 minutes, for example. Also, the coating layer of the medium 2 may have an Spd of 600 [mm] when heated under the same conditions. -2 The coating layer may be made of a material having a Spd of 600 or less. When a medium 2 provided with such a coating layer is used, ink beading can be further suppressed by applying the technology disclosed herein. However, it should be noted that the Spd of the coating layer is not particularly limited in the technology disclosed herein. The coating layer may be made of a material whose Spd is reduced from more than 600 to 600 or less by the heating described above, as well as a material whose Spd is 600 or less before heating.

[0031] (Thickness of medium 2) The thickness of medium 2 is not particularly limited. The thickness of medium 2 can be the sum of the thickness of the substrate and the thickness of the coating layer. For example, the thickness of medium 2 is 0.2 mm or more and 0.6 mm or more and 0.3 mm or more and 0.5 mm or less. The thickness of medium 2 can be measured in accordance with JIS P 8118:2014.

[0032] (Basis weight of medium 2) The basis weight of medium 2 is not particularly limited. For example, the basis weight could be 100 g / m². 2 More than 700g / m 2 Below 200g / m 2 More than 600g / m2 The following applies. Note that the basis weight of medium 2 can be measured in accordance with JIS P 8124:2011.

[0033] The uses of medium 2 are not particularly limited. Examples of uses for medium 2 include industrial printing, general paper packaging, and packaging paper. Examples of items to be packaged include food, confectionery, daily necessities, textile products, tissues, plastic wrap, pharmaceuticals, and electronic components.

[0034] As medium 2, commercially available products may be used. Examples of commercially available products include the "OK Ball" series, "UF Coat" series, "Suncoat (registered trademark)" series, "MC Ball" series, and "Sundia White N" series from Oji Materia Co., Ltd.; the "S Pearl Card (registered trademark)" series and "N Pearl Deluxe (registered trademark)" series from Mitsubishi Paper Mills Ltd.; the "Maricoat (registered trademark)" series from Hokuetsu Corporation; and the "JETSTAR (registered trademark)" series and "Ibest (registered trademark) WF" series from Nippon Paper Industries Co., Ltd.

[0035] (ink) The ink is applied to the coating layer of the medium 2 after the medium 2 has been heated by the heating device 30. The ink includes, for example, a colorant, a resin, and water.

[0036] (Colorants) Examples of colorants include pigments and dyes that are dispersible in water by resin dispersants or by self-dispersion. Examples of pigments include carbon black, inorganic pigments, and organic pigments. Examples of carbon black include furnace black, lamp black, acetylene black, and channel black. Examples of inorganic pigments include titanium dioxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments, polycyclic pigments, dye lake pigments, nitro pigments, nitroso pigments, and aniline black daylight fluorescent pigments. Other pigments include, for example, CI Pigment Black 1, 6, 7; CI Pigment Yellow 1, 2, 3, 12, 13, 14, 15, 16, 17, 55, 73, 74, 75, 78, 83, 93, 94, 95, 97, 98, 114, 128, 129, 138, 150, 151, 154, 155, 180, 185, 194; CI Pigment Orange 31, 43; CI Pigment Red 2, 3, 5, 6, 7, 12, 15, 16, 48, 48:1, 48:3, 53:1 Examples include 57, 57:1, 112, 122, 123, 139, 144, 146, 149, 150, 166, 168, 175, 176, 177, 178, 184, 185, 190, 202, 209, 221, 222, 224, 238, 254, CI Pigment Violet 19, 196, CI Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 16, 22, 60, CI Pigment Green 7, 36, and solid solutions of these pigments. The ink may contain only pigments or only dyes as colorants. These colorants may be used individually or in combination of two or more types.

[0037] (resin) Examples of resins include acrylic resins, urethane resins, polyvinyl chloride resins, polyester resins, styrene resins, polyolefin resins, vinyl acetate resins, polyvinyl chloride resins, butadiene resins, benzoguanamine resins, phenolic resins, silicone resins, epoxy resins, paraffin resins, fluororesins, water-soluble resins, and copolymer resins thereof. These resins may be used individually or in combination of two or more types.

[0038] The resin may contain resin particles. These resin particles may, for example, be contained in an emulsion. The emulsion, for example, is composed of resin particles and water. The resin particles are not dissolved in water, but are dispersed in the water within a specific particle size range.

[0039] (water) Examples of water include deionized water and purified water. The water content may be, for example, the remainder of the other components.

[0040] (Other ingredients) The ink may further contain surfactants and water-soluble organic solvents as other components.

[0041] (Surfactants) Surfactants can be appropriately selected depending on the purpose. Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, acetylene glycol-based surfactants, fluorine-based surfactants, and silicone-based surfactants. These surfactants may be used individually or in combination of two or more types.

[0042] (Water-soluble organic solvent) Examples of water-soluble organic solvents include alkyl alcohols with 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; alkylene glycols containing 2 to 6 carbon atoms in the alkylene group, such as ethylene glycol, propylene glycol, butylene glycol, 1,2-butanediol, triethylene glycol, 1,6-hexanediol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; glycerin, ethylene glycol monomethyl (or ethyl, propyl, butyl) ether, and diethylene glycol monomethyl ( Examples include lower alkyl ethers of alkylene glycols such as ethyl, propyl, or butyl ether, triethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, tetraethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, propylene glycol monomethyl (or ethyl, propyl, butyl) ether, dipropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, butyl) ether, and tetrapropylene glycol monomethyl (or ethyl) ether; and N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc. These water-soluble organic solvents may be used individually or in combination of two or more types.

[0043] The ink may further contain conventionally known additives as needed. Examples of additives include pH adjusters, viscosity modifiers, and preservatives. Examples of viscosity modifiers include polyvinyl alcohol, cellulose, and water-soluble resins.

[0044] Ink can be prepared, for example, by uniformly mixing a resin, a colorant, a surfactant, a water-soluble organic solvent, water, and other additives as needed, using a known method, and then removing insoluble materials using a filter or the like.

[0045] (Surface treatment method) Next, a surface treatment method using the surface treatment system 10 will be described. The surface treatment method comprises a heating step and an adhesion step. The heating step and the adhesion step are performed in this order. The control unit 26 executes each step in response to, for example, a processing execution instruction being input to the surface treatment system 10 from an external source. When the above instruction is input, the control unit 26 transports the medium 2 on the transport path 100 by controlling each part such as the supply roller 16 and the transport device 18.

[0046] (Heating process) In the heating process, the medium 2 is heated under conditions that satisfy a predetermined heating temperature and heating time. These conditions are such that when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0). Figures 2 and 3 are graphs showing the relationship between heating temperature and heating time in the heating process. In Figures 2 and 3, the hatched areas represent the range that satisfies the above relationship. Based on the input processing execution instruction, the control unit 26 controls the transport speed of the medium 2 passing through the transport path 100 and commands the control unit 34 to set the heating temperature of the medium 2. For example, when the control unit 26 sends a command to the control unit 34 to control the heating temperature of the medium 2 to 70°C, it adjusts the transport speed of the medium 2 passing through the transport path 100 by controlling the operation of the first roller pair 20, etc., so that the heating time is approximately 202 seconds or more. The upper limit of the heating temperature in the heating process is not particularly limited, but for example, it may be 150°C or less. By setting the heating temperature to 150°C or lower, it is possible to suppress beading while also suppressing discoloration of the medium 2 due to the heat treatment. Furthermore, if the heating temperature is between 130°C and 150°C, the heat treatment may be performed in such a way that the relationship Y < -2X + 313 is further satisfied. In Figure 4, the hatched area represents the range in which the above relationship is further satisfied. By adjusting the heating time to satisfy this relationship, discoloration of the medium 2 can be further suppressed. The heating time is the time from when the downstream end of the medium 2 enters below the heating section 32 until the downstream end exits from below the heating section 32 during the transport process of the medium 2. The processing instruction may specify both the heating temperature and the heating time, or it may specify only one of the heating temperature or heating time.

[0047] (Adhesion process) In the adhesion process, ink is applied to the surface of the medium 2. The control unit 44 controls the piezoelectric elements, etc., corresponding to each nozzle 42a based on commands from the control unit 26. By controlling these piezoelectric elements, the control unit 44 selectively ejects ink from each nozzle 42a toward the medium 2 passing below the head 42. As a result, ink is applied to the surface of the medium 2.

[0048] If there are many fine irregularities on the surface of medium 2, adjacent dots tend to aggregate, making beading more likely. In the surface treatment method described above, medium 2 is heated in the heating step under the conditions that X≧70 and Y>-0.04X+6.165 (where Y>0). In other words, in the surface treatment method described above, higher energy is applied to medium 2 in the heating step than in various treatments that are generally performed on medium 2. Commonly performed treatments include, for example, corona treatment, plasma treatment, preheating, and ink drying. The surface of medium 2 is provided with a coating layer containing a binder. Therefore, by performing the heating step, the binder contained in the coating layer softens, and the surface of the coating layer is smoothed. That is, the fine irregularities that may exist on the surface of the coating layer are reduced. As a result, when ink is applied to the surface of the coating layer, the wettability of the ink improves, and the ink adheres more uniformly to the surface of the coating layer. As a result, it is thought that the surface treatment method described above can suppress ink beading.

[0049] (Correspondence) The heating device 30 and the adhesion device 40 are examples of a "manufacturing apparatus that performs a process on a medium to produce a treated medium." The surface treatment system 10 is an example of a "manufacturing system that performs a process on a medium to produce a treated medium." The surface treatment method is an example of a "manufacturing method that performs a process on a medium to produce a treated medium." [Examples]

[0050] Next, the technologies disclosed herein will be described in detail with reference to examples and comparative examples. However, the technologies disclosed herein are not limited in any way to these examples.

[0051] (Measurement of mountain peak density Spd) First, each medium described in Tables 1 to 4 was placed on a metal tray with the coated layer facing upward. The metal tray with the medium placed thereon was placed in a dry oven DX402 manufactured by Yamato Scientific Co., Ltd., and heated at 150°C for 60 minutes. The medium before heating and the medium after heating were each cut into 5 cm × 5 cm pieces, and Spd was measured for each piece using a device VK-X1100 manufactured by Keyence Corporation, in accordance with the test method conforming to ISO25178. The Spd of each medium after heating and the rate of change in Spd of each medium before and after heating are shown in Tables 1 to 4, respectively.

[0052] The notations for each medium in Tables 1 to 4 are described below. OK Ball (manufactured by Oji Materia Co., Ltd., basis weight: 350 g / m 2 ) S Pearl Card (manufactured by Mitsubishi Paper Mills Limited, basis weight: 350 g / m 2 ) Maricoat (manufactured by Hokuetsu Corporation, basis weight: 350 g / m 2 ) Suncoat (manufactured by Oji Materia Co., Ltd., basis weight: 350 g / m 2 )

[0053] (Preparation of heated samples) For each example, the medium shown in Tables 1 to 4 was placed on a metal tray with the coated layer facing upward. The metal tray with the medium placed thereon was placed in a dry oven DX402 manufactured by Yamato Scientific Co., Ltd., and heat treatment was performed respectively for the heating time and at the heating temperature shown in Tables 1 to 4. Thereafter, the medium was air-cooled to room temperature, and this was used as a heated sample. Further, in each example, a medium that had not been subjected to the heat treatment was used as an unheated sample.

[0054]

Table 1

[0055]

Table 2

[0056]

Table 3

[0057] [Table 4]

[0058] (Evaluation of discoloration of the media) For each example, the optical density of the heated sample and the optical density of the unheated sample were measured using an X-Rite eXact spectrophotometer under the following conditions. Light source:D 50 Field of view: 2°, density measurement conditions: M0, density status: Status-T, density white standard: absolute value The optical density difference ΔE between the heated sample and the unheated sample was calculated based on the CIEDE2000 color difference formula. The color change of the medium was evaluated based on the calculated ΔE according to the following criteria. The evaluation results are shown in Tables 1 to 4. A: ΔE is less than 1.0 B: ΔE is 1.0 or greater

[0059] (Evaluation of image quality improvement effect) For each example, heated and unheated samples were placed in a Brother Industries, Ltd. MFC-J7500CDW printer. Using ink A having the composition shown in Table 5, the amount ejected from the inkjet head was adjusted to 10 pL per pixel, and multiple 10 mm x 10 mm patch images were formed at a resolution of 600 dpi x 600 dpi. Each patch image was formed while increasing the print duty cycle in 10% increments, and the presence or absence of beading was visually checked. The print duty cycle immediately preceding the print duty cycle of a patch image in which beading was visually confirmed was defined as the maximum print duty cycle. Print duty cycle refers to the ratio of the total printed area to the medium. Furthermore, a larger maximum print duty cycle means that beading will not occur even if the ink is applied more densely. In Examples 26-29, the notation "<70" indicates that while slight beading occurs in patch images with a print duty cycle of 70%, the degree of beading is reduced compared to patch images with a print duty cycle of 70% in the unheated sample. In each example, the difference between the maximum print duty cycle of the heated sample and the maximum print duty cycle of the unheated sample was calculated, and the image quality improvement effect was evaluated according to the following criteria. The maximum print duty cycles of the heated and unheated samples for each example, and the evaluation results, are shown in Tables 1-4. In Table 5, the magenta resin-dispersed pigment is an aqueous dispersion of CI Pigment Red 122 containing a resin dispersant. The numerical values ​​in the columns indicating each component represent the content of that component relative to the total amount of ink A, and the unit is mass%. A: Maximum print duty cycle increased by more than 10% B: Maximum print duty cycle increases by more than 0% but less than 10%. C: No change in maximum print duty cycle.

[0060] [Table 5]

[0061] As shown in Tables 1 to 3, in Examples 1 to 29, the maximum printing duty cycle increased by more than 10% due to the heat treatment. In other words, in Examples 1 to 29, the heat treatment resulted in a good improvement in image quality.

[0062] In contrast, in Comparative Example 1, the heating temperature was lower than in each of the examples. In Comparative Example 1, OK Ball, which was also used in the examples, was used as the medium. However, because the heating temperature was low at 60°C, the binder in the coating layer did not soften sufficiently even after heating for 180 minutes. As a result, the surface of the coating layer was not easily smoothed even after the heat treatment. Consequently, it is thought that the wettability of the ink to the coating layer did not improve before and after the heat treatment, and the image quality improvement effect was not achieved.

[0063] Furthermore, in Comparative Examples 2-6, although the heating temperature was 70°C or higher, as shown in Figure 3, the relationship between the heating temperature and heating time in the heat treatment falls outside the hatched area. More specifically, in Comparative Examples 2-6, the heating time was shorter compared to each example where the heat treatment was performed at the corresponding heating temperature. In Comparative Examples 2-6, despite performing the heat treatment at a sufficient heating temperature, the heating time was too short, resulting in insufficient heating to soften the binder. Consequently, the surface of the coating layer was not easily smoothed even after the heat treatment. As a result, it is believed that the wettability of the ink to the coating layer did not improve before and after the heat treatment, and the image quality improvement effect was not achieved.

[0064] Next, comparing each example, Examples 14, 17, and 20-23 showed slightly lower evaluations of media discoloration compared to the other examples. The heat treatment in Example 14 was 130°C for 60 minutes, the heat treatment in Example 17 was 140°C for 50 minutes, and the heat treatments in Examples 20-23 were 150°C for 15 minutes or more. In other words, in these examples, the relationship between heating temperature and heating time in the heat treatment is outside the area shown by hatching in Figure 4. More specifically, in these examples, the heating time is longer compared to the other examples where the heat treatment was performed at the corresponding heating temperature. In these examples, although the image quality improvement effect was fully demonstrated, it is thought that some discoloration of the media was observed because the heating time was relatively long relative to the heating temperature. From these results, it was found that when performing heat treatment at high temperatures, the image quality improvement effect can be obtained while suppressing media discoloration by performing the heat treatment for an appropriate heating time.

[0065] Furthermore, Examples 24 and 25 were heat-treated under the same conditions as Examples 21 and 22, except for the type of medium used. The medium used in Examples 21 and 22, "OK Ball," has a relatively large surface free energy of 57.6 [mN / m]. Also, the Spd of "OK Ball" after heating at 150°C for 60 minutes was 270.0 [mm²]. -2 The surface free energy (Spd) is relatively small, and the Spd is reduced by 28.2% compared to before heating. The medium "S Pearl Card" used in Examples 24 and 25 has a relatively large surface free energy of 47.6 [mN / m]. In addition, the Spd of "S Pearl Card" after heating at 150°C for 60 minutes is 522.3 [mm -2The Spd is relatively small, and the Spd is reduced by 39.2% compared to before heating. Thus, in Examples 24 and 25, similar to Examples 21 and 22, the surface free energy of the coating layer of the medium is relatively large, and the wettability of the ink to the coating layer is relatively high. In addition, because the Spd after heat treatment was kept to a suitably small value, local aggregation of ink is less likely to occur. As a result, it is considered that a good image quality improvement effect was obtained. Note that in the case of "S Pearl Card", the Spd before heating is a very large value of about 859, but it can be seen that beading was suitably suppressed because the Spd was sufficiently reduced by heat treatment.

[0066] Furthermore, Examples 26 and 27 were heat-treated under the same conditions as Examples 21 and 22, except for the type of medium used. The medium used in Examples 26 and 27, "Malicoat," has a relatively low surface free energy of 44.1 [mN / m]. In addition, the Spd of "Malicoat" after heating at 150°C for 60 minutes was 631.8 [mm²]. -2 The surface free energy of the coating layer of the medium is relatively large, and the Spd is reduced by only 7.8% compared to before heating. Thus, in Examples 26 and 27, the surface free energy of the coating layer of the medium is relatively small, and the wettability of the ink to the coating layer is relatively low. Also, because the Spd after heating was not reduced so much, local aggregation of the ink is likely to occur. From these results, it can be seen that a better image quality improvement effect can be obtained by using a medium with a relatively large surface free energy and a relatively small Spd after heating. Specifically, the surface free energy of the medium is 47 [mN / m], and the Spd after heating at 150°C for 60 minutes is 600 [mm -2 It can be seen that using a medium such as the following results can produce a better image quality improvement effect. The same results as those for Examples 26 and 27 were obtained for Examples 28 and 29.

[0067] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. Modifications of the above embodiments are listed below.

[0068] (Variation 1) In the embodiments described above, the medium 2 may be any medium having a coating layer on at least one surface of the substrate. For example, the coating layer may be provided on both sides of the substrate.

[0069] (Modification 2) In the embodiment described above, the surface treatment system 10 may include a roller to support the medium 2 and a roller to wind up the medium 2 instead of the supply tray 14, the supply roller 16, and the discharge tray 24. In other words, the surface treatment system 10 may be a roll-to-roll system.

[0070] (Variation 3) In the embodiment described above, the heating device 30 and the adhesion device 40 were configured as separate components, but the heating device 30 and the adhesion device 40 may be configured as an integrated unit.

[0071] (Modification 4) In the embodiment described above, the adhesion device 40 adheres ink to the medium 2 using an inkjet method. However, the adhesion device 40 may also employ methods such as blade coating, roll coating, or spray coating to adhere ink to the medium 2.

[0072] (Variation 5) In the above-described embodiment, the surface treatment system 10 may further include a drying device for drying the ink discharged onto the medium 2 passing through the transport path 100. The drying device may include, for example, a dryer, a heat gun, an oven, an IR heater, etc. Instead of providing a drying device, after the ink is applied to the medium 2 in the surface treatment system 10, it may be left for a predetermined period of time to evaporate a predetermined amount of water-containing components in the ink. That is, after the ink is applied to the medium 2 in the surface treatment system 10, the ink on the medium 2 may be allowed to air dry without using a drying device. In other words, the surface treatment method may include a drying step after the application step.

[0073] (Experimental variation 6) In the embodiment described above, the surface treatment system 10 may further include a cooling device for cooling the medium 2 heated by the heating device 30. Alternatively, instead of providing a cooling device, the medium 2 may be left to cool for a predetermined period after heating in the surface treatment system 10. That is, after heating the medium 2 in the surface treatment system 10, the medium 2 may be allowed to dissipate heat naturally without using a cooling device. In other words, the surface treatment method may include a cooling step after the heating step and before the adhesion step.

[0074] (Example 7) In the above-described embodiment, the heating time of the medium 2 by the heating device 30 may be, for example, the time from when the downstream end of the medium 2 enters below the heating unit 32 until the upstream end of the medium 2 exits from below the heating unit 32 during the process of the medium 2 being transported, or it may be the time when the entire medium 2 in the transport direction is located below the heating unit 32, or it may be the time when the medium 2 is located inside the heating device 30.

[0075] Furthermore, the technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness.

[0076] Even if, in the claims of this patent application, each claim depends on only some of the claims, it is not limited to the claim being dependent only on those specific claims. To the extent that it is not technically contradictory, each claim may be dependent on other claims that were not dependent at the time of application. That is, the technologies of each claim can be combined in various ways as follows: (Item 1) A manufacturing method for producing a processed medium by performing a process on the medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing method is A heating step for heating the aforementioned medium, The process includes, after the heating step, an adhesion step of applying ink to the coating layer, A manufacturing method in which, in the heating step, the medium is heated such that when the heating temperature is X [°C] and the heating time is Y [minutes], the relationship X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0) is satisfied. (Item 2) In the heating step, the medium is heated such that the relationship X ≤ 150 is satisfied. The manufacturing method according to item 1, wherein the medium is heated such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150. (Item 3) The manufacturing method according to item 1 or 2, wherein the surface free energy of the coating layer is 47 [mN / m] or more. (Item 4) The manufacturing method according to any one of items 1 to 3, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating. (Item 5) When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. -2 A manufacturing method described in any of items 1 to 4, comprising the following materials. (Item 6) The manufacturing method according to any one of items 1 to 5, wherein the adhesion step involves adhering ink to the coating layer using an inkjet method. (Item 7) A manufacturing apparatus that performs processing on a medium to produce a processed medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing apparatus, A heating device for heating the aforementioned medium, The system includes an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device, The heating device is a manufacturing apparatus that heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0). (Item 8) The heating device heats the medium such that the relationship X ≤ 150 is satisfied. The manufacturing apparatus according to item 7, which heats the medium such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150. (Item 9) The manufacturing apparatus according to item 7 or 8, wherein the surface free energy of the coating layer is 47 [mN / m] or more. (Item 10) The manufacturing apparatus according to any one of items 7 to 9, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating. (Item 11) When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. -2 A manufacturing apparatus described in any of items 7 to 10, comprising the following materials: (Item 12) The aforementioned attachment device is a manufacturing device according to any one of items 7 to 11, which attaches ink to the coating layer using an inkjet method. (Item 13) A manufacturing system that performs processing on a medium to produce a processed medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing system, A heating device for heating the aforementioned medium, The system includes an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device, The heating device is a manufacturing system that heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0). (Item 14) The heating device heats the medium such that the relationship X ≤ 150 is satisfied. The manufacturing system according to item 13, wherein the medium is heated such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150. (Item 15) The manufacturing system according to item 13 or 14, wherein the surface free energy of the coating layer is 47 [mN / m] or more. (Item 16) The manufacturing system according to any one of items 13 to 15, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating. (Item 17) When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. -2A manufacturing system described in any of items 13-16, comprising the following materials: (Item 18) The aforementioned attachment device is a manufacturing system according to any one of items 13 to 17, wherein ink is attached to the coating layer by an inkjet method. [Explanation of symbols]

[0077] 2: Medium, 10: Surface treatment system, 12: Housing, 14: Supply tray, 16: Supply roller, 18: Conveying device, 20: First roller pair, 22: Second roller pair, 24: Discharge tray, 26: Control unit, 30: Heating device, 40: Adhesion device, 100: Conveying path

Claims

1. A manufacturing method for producing a processed medium by performing a process on the medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing method is A heating step for heating the aforementioned medium, The process includes, after the heating step, an adhesion step of applying ink to the coating layer, A manufacturing method in which, in the heating step, the medium is heated such that when the heating temperature is X [°C] and the heating time is Y [minutes], the relationship X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0) is satisfied.

2. In the heating step, the medium is heated such that the relationship X ≤ 150 is satisfied. The manufacturing method according to claim 1, wherein the medium is heated such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150.

3. The manufacturing method according to claim 1, wherein the surface free energy of the coating layer is 47 [mN / m] or more.

4. The manufacturing method according to claim 1, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating.

5. When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. －２ The manufacturing method according to claim 1, comprising the following materials.

6. The manufacturing method according to claim 1, wherein the adhesion step involves adhering ink to the coating layer using an inkjet method.

7. A manufacturing apparatus that performs processing on a medium to produce a processed medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing apparatus, A heating device for heating the aforementioned medium, The system includes an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device, The heating device is a manufacturing apparatus that heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0).

8. The heating device heats the medium such that the relationship X ≤ 150 is satisfied. The manufacturing apparatus according to claim 7, wherein the medium is heated such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150.

9. The manufacturing apparatus according to claim 7, wherein the surface free energy of the coating layer is 47 [mN / m] or more.

10. The manufacturing apparatus according to claim 7, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating.

11. When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. －２ The manufacturing apparatus according to claim 7, comprising the following materials.

12. The manufacturing apparatus according to claim 7, wherein the adhesion device adheres ink to the coating layer using an inkjet method.

13. A manufacturing system that performs processing on a medium to produce a processed medium, The aforementioned medium is a cardboard sheet having a coating layer containing a binder on its surface. The aforementioned manufacturing system, A heating device for heating the aforementioned medium, The system includes an adhesion device for applying ink to the coating layer after the medium has been heated by the heating device, The heating device is a manufacturing system that heats the medium such that, when the heating temperature is X [°C] and the heating time is Y [minutes], X ≥ 70 and Y > -0.04X + 6.165 (where Y > 0).

14. The heating device heats the medium such that the relationship X ≤ 150 is satisfied. The manufacturing system according to claim 13, wherein the medium is heated such that the relationship Y < -2X + 313 is further satisfied when 130 ≤ X ≤ 150.

15. The manufacturing system according to claim 13, wherein the surface free energy of the coating layer is 47 [mN / m] or more.

16. The manufacturing system according to claim 13, wherein the medium is made of a material such that when heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is reduced by 10% or more compared to before heating.

17. When the medium is heated at 150°C for 60 minutes, the peak density Spd on the surface of the coating layer is 600 [mm²]. －２ The manufacturing system according to claim 13, comprising the following materials.

18. The manufacturing system according to claim 13, wherein the adhesion device adheres ink to the coating layer using an inkjet method.

Images