Corrugated board and antibacterial / antiviral corrugated board processing method

Abstract

To provide a corrugated cardboard that can be protected from bacterial and viral contamination at low cost and an antibacterial-antiviral corrugated cardboard processing method.SOLUTION: A corrugated cardboard has a print ink layer formed with print ink, and an antibacterial-antiviral layer where the print ink layer is coated with an antibacterial-antiviral agent. In the corrugated cardboard, an average coating amount at a print site of the print ink layer is smaller than an average coating amount of the antibacterial-antiviral layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to antibacterial and antiviral treated corrugated cardboard and a method for treating the same. [Background technology]

[0002] A conventional method for processing this type of antibacterial cardboard is disclosed, for example, in Patent Document 1. In the method for processing antibacterial cardboard disclosed in Patent Document 1, the surface of the cardboard is coated with an antibacterial agent after printing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication No. 8-151037 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the processing method described in Patent Document 1 requires an additional step of coating the surface of the cardboard with an antibacterial agent after the printing process, and such a configuration may be costly.

[0005] Therefore, an object of the present invention is to provide cardboard that is configured to suppress bacterial and viral contamination at low cost, and a method for processing antibacterial and antiviral cardboard. [Means for solving the problem]

[0006] One form of corrugated board of the present invention is a corrugated board having a printed ink layer formed with printing ink and an antibacterial and antiviral layer formed by coating the printed ink layer with an antibacterial and antiviral agent, and is characterized in that the average application amount of the printed ink layer in printed areas is less than the average application amount of the antibacterial and antiviral layer.

[0007] Furthermore, one embodiment of the antibacterial and antiviral cardboard processing method of the present invention is a method for processing antibacterial and antiviral cardboard having a plurality of printing devices in one printing step, comprising: (a) a step of printing on a surface of the cardboard with printing ink by the printing devices; and (b) a step of printing an antibacterial and antiviral agent on the surface of the cardboard by the printing devices, characterized in that step (b) is performed after step (a).

[0008] In the present specification and claims, the term "antibacterial agent (antibacterial drug)" refers to a substance having a function of suppressing the growth of bacteria, the term "antiviral agent (antiviral drug)" refers to a substance having a function of inactivating viruses, and the term "antibacterial and antiviral agent" refers to a substance having antibacterial and / or antiviral functions. In the present invention, the terms "layer containing an antibacterial and antiviral agent" and "antibacterial and antiviral layer" refer to a layer formed by directly applying the "antibacterial and antiviral agent" to the surface of an object, and a layer composed of a printed ink layer of an object and an antibacterial and antiviral layer formed by covering the printed ink layer. In the present invention, the term "antibacterial and antiviral agent" refers to an active ingredient alone having antibacterial and / or antiviral functions, and also refers to a paint or ink having antibacterial and antiviral functions obtained by adding the active ingredient to a vehicle (alkali-soluble resin, emulsion resin, alkali component, water, etc.) and various auxiliary agents (dispersant, crosslinking agent, defoamer, etc.). Effect of the Invention

[0009] According to the present invention, bacterial and viral infections can be suppressed at low cost. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing a cardboard box making device according to an embodiment of the present invention. [Diagram 2] 2 is an explanatory diagram illustrating the process of forming a folding box from the cardboard of FIG. 1. FIG. [Diagram 3]1 is a schematic cross-sectional view of a printing process for cardboard according to one embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a perspective view showing a printing process on a cardboard according to an embodiment of the present invention. [Diagram 5] 1 is a schematic cross-sectional view of a cut sheet of corrugated board according to one embodiment of the present invention; [Figure 6] 1 is a table showing the results of a comparison of the type of ink printed on the corrugated board according to the present invention and the antibacterial activity value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will now be described in detail with reference to the drawings.

[0012] <Overall structure and operation of this box making device> FIG. 1 is a schematic cross-sectional view showing a cardboard box making device 100 according to one embodiment of the present invention. The cardboard box making device 100 of this embodiment includes a printing device 10 that performs flexographic printing on a cut sheet S of cardboard, a blank forming device 20 having a rotary creaser that puts lines for folding the printed cut sheet S in the vertical direction and a rotary slotter that performs vertical cuts such as groove cutting to form a blank sheet of the developed shape of a cardboard case from the cut sheet S, and a processing device 30 that performs processing such as hand holes and H cuts with a punching die. The cardboard box making device 100 also includes a folding device 40 that forms a sleeve S' from the blank sheet supplied from the processing device 30, and a stacking device 50 that stacks the sleeves S' transported from the folding device 40. The stacking device 50 is arranged downstream of the folding device 40, and a plurality of conveyors that transport the sleeves S' are arranged between the folding device 40 and the stacking device 50.

[0013] As shown in FIG. 2, cut cardboard sheets S are pre-lined with lines for folding horizontally. After printing by printer 10, cut sheets S are transported to processing device 30, where processing is performed such as lines for folding vertically, a glue allowance for forming a cardboard case, and hand holes and H-cuts. After processing, cut sheets S are transported to folding device 40, where cut sheets S are folded to generate sleeves S'. Sleeves S' are then transported to stacking device 50, where a predetermined number of sleeves S' are stacked. The stacked sleeves S' are distributed to the market as a single unit.

[0014] <Printing device structure> Fig. 3 is a schematic cross-sectional view of a printing process on a corrugated board according to one embodiment of the present invention. Fig. 4 is a perspective view showing a printing process on a corrugated board according to this embodiment. Fig. 5 is a schematic cross-sectional view of a cut sheet of a corrugated board according to one embodiment of the present invention.

[0015] The printing device 10 of this embodiment is provided with three printing devices 10a, 10b, and 10c for using three types of printing ink (see FIG. 1). In detail, the printing devices 10a and 10b print characters, figures, and the like (patterns) on the cut sheet S using quick-drying and water-resistant printing ink. Hereinafter, the printing ink for pattern printing will be abbreviated to "printing ink". On the other hand, the printing device 10c uses an antibacterial and antiviral agent to apply (or print) on the printing by the printing devices 10a and 10b. In other words, it is composed of an antibacterial and antiviral layer Ic in which the printing ink layers Ia and Ib provided by the printing ink are covered with the antibacterial and antiviral agent. This makes it possible to print characters, figures, and the like on the cut sheet S while printing the antibacterial and antiviral agent, that is, in one printing process, it is possible to both display characters, figures, and the like on the cut sheet S and inhibit the growth of bacteria and inactivate viruses. Also, the printing ink layer may be made into a multi-layered layer, and an antibacterial / antiviral agent may be applied thereon. In the present invention, the antibacterial / antiviral agent means an active ingredient alone having antibacterial and / or antiviral functions, and also means a paint or ink having antibacterial / antiviral functions obtained by adding the active ingredient to a vehicle (alkali-soluble resin, emulsion resin, alkali component, water, etc.) and various auxiliary agents (dispersant, crosslinking agent, defoamer, etc.). In this embodiment, printing was performed using three printing devices, but the present invention is not limited to this number as long as the effects of the present invention are exhibited.

[0016] Flexographic inks used on corrugated board consist of colorants, vehicles (intended to be fixed to the surface), additives, etc., and the vehicles consist of resins and solvents. Water-resistant printing inks mainly use emulsion-based resins with added polymerization accelerators, which increases resistance to water after fixing. Quick-drying printing inks use solvents with high vapor pressure and are concentrated by using low-viscosity resins, which reduces the drying load.

[0017] The antibacterial agent used in the present invention is preferably an inorganic antibacterial agent, and examples thereof include those in which silver or silver ions are supported on an inorganic substance as used in the present embodiment, and those containing copper, copper ions, zinc, zinc ions, or the like as an active ingredient.

[0018] Furthermore, examples of the antiviral agent used in the present invention include linear sodium alkylbenzenesulfonate, alkylglycosides, alkylamine oxides, benzalkonium chloride, benzethonium chloride, dialkyldimethylammonium chloride, and polyoxyethylene alkyl ethers.

[0019] A feature of the cardboard of this embodiment is that the average application amount of printing ink in the printed areas of the printed ink layers Ia and Ib is less than the average application amount of the antibacterial and antiviral agent in the antibacterial and antiviral layer Ic which coats the printed ink layers Ia and Ib with the antibacterial and antiviral agent.

[0020] The reason for the amount of printing ink applied being less than the amount of antibacterial and antiviral agent applied is that in order for antibacterial and antiviral properties to be exerted, the active ingredients of the antibacterial and antiviral agents need to be exposed on the surface; however, if the amount of printing ink applied in the layer below is too great, the active ingredients in the antibacterial and antiviral layer will permeate into the printing ink layer.

[0021] The upper limit of the ratio of the antibacterial / antiviral agent to the printing ink coating amount is 3.0. The reason for this is that coating more than a certain amount of antibacterial / antiviral agent not only results in a plateau in effectiveness and is cost-inefficient, but also causes the antibacterial / antiviral layer to take a long time to dry, causing the active ingredients to sink, which in turn reduces the antibacterial / antiviral effect. The more preferable range of the coating amount ratio is 1.0 to 1.6.

[0022] The antibacterial and antiviral agent is more expensive than the printing ink used to print characters, figures, etc. Therefore, by using a quick-drying, water-resistant printing ink, the printing devices 10a and 10b can prevent the antibacterial and antiviral agent applied by the printing device 10c in the subsequent process from penetrating into the quick-drying, water-resistant printing ink.

[0023] Furthermore, a feature of the cardboard case that has been subjected to the antibacterial and antiviral treatment of this embodiment is that the Zahn cup viscosity of the printing ink in the printed ink layers Ia and Ib is lower than the Zahn cup viscosity of the antibacterial and antiviral agent in the antibacterial and antiviral layer Ic that coats the printed ink layers Ia and Ib with the antibacterial and antiviral agent.

[0024] The reason why it is preferable for the viscosity of the design ink to be lower than the viscosity of the antibacterial and antiviral agent is that in order for the antibacterial and antiviral functions to be exerted, the active ingredients that exert the antibacterial and antiviral functions must be exposed on the surface, but if the viscosity of the design ink is high, the design ink layer formed on the base paper becomes thicker, making it easier for the antibacterial and antiviral agent applied on top of that to penetrate into the design ink layer. Therefore, it is thought that increasing the viscosity of the antibacterial and antiviral agent is effective in suppressing penetration.

[0025] Moreover, the upper limit of the viscosity ratio is preferably 2.0. The reason is that if the viscosity of the antibacterial and antiviral agent is made too high in printing equipment that is matched to the ink viscosity, various operational problems will occur. The most preferable range of the viscosity ratio is 1.0 to 1.5.

[0026] As a result, the printing ink of the printing devices 10a and 10b spreads and dries more easily on the cut sheet S than the antibacterial and antiviral agent, thereby suppressing the penetration of the antibacterial and antiviral agent.

[0027] The printing device 10 includes an ink reservoir 11 that contains printing ink I, an ink supply port 11a that supplies the printing ink I from the ink reservoir 11 through a passage 11b, an anilox roll 12 that has minute recesses formed therein to obtain a desired printing pattern or the like, a doctor roll 13 that adjusts the amount of printing ink I supplied from the ink supply port 11a to an appropriate amount, a plate cylinder 14 that has a printing plate 14a, a receiving roll 15 that conveys the cut sheet S by holding it together with the plate cylinder 14, and a pair of conveying rolls 16 that convey the cut sheet S to a post-processing step. A cover 18 is arranged around the anilox roll 12 and the doctor roll 13 to prevent ink from scattering. The printing device 10 adjusts the amount of printing ink I that adheres to the anilox roll 12 by bringing the doctor roll 13 into contact with the anilox roll 12, which is supplied from the ink supply port 11a, and then transfers the printing ink I transferred from the anilox roll 12 to the printing plate 14a onto the cut sheet S that passes between the plate cylinder 14 and the backing roll 15 from the upstream side to the downstream side in the transport direction T, thereby printing. The printing speed of cardboard is usually 150 to 350 sheets / min. The printed cut sheet S is transported downstream by a pair of transport rolls 16 arranged downstream of the plate cylinder 14 and the backing roll 15.

[0028] The anilox roll 12 is a cylindrical roll body covered with ceramics or chrome plating, and is supported rotatably in a state in which it is arranged parallel to the doctor roll 13. The anilox roll 12 is connected to a drive motor (not shown) and can rotate during printing. Small cells are uniformly arranged and formed as recesses on the outer circumferential surface of the anilox roll 12 to accommodate the printing ink I. The anilox roll 12 and the doctor roll 13 receive the supply of the printing ink I, adjust the amount of the printing ink I, and transfer the printing ink I to the plate cylinder 14 while rotating the anilox roll 12 in the direction of the arrow A. An ink receiver Ir is provided at one end of the anilox roll 12 and the doctor roll 13, and excess printing ink I is collected in the ink receiver Ir. The ink receiver Ir and the ink reservoir 11 are connected via a passage 11c, and the printing ink I accumulated in the ink receiver Ir is returned to the ink reservoir 11 via the passage 11c. In this way, the anilox roll 12, together with the doctor roll 13, can transfer an appropriate amount of printing ink I to the plate cylinder 14.

[0029] The doctor roll 13 is a roll body in which cylindrical rubber members are laminated, and is supported rotatably. The outer peripheral surface of the cylindrical rubber member is formed to be a smooth surface. The doctor roll 13 is connected to a drive motor (not shown) and can rotate during printing. The outer diameter of the doctor roll 13 is formed to be approximately the same as the outer diameter of the anilox roll 12.

[0030] The plate cylinder 14 is a cylindrical body with a printing plate 14a fixed to its periphery, and is disposed below the anilox roll 12 in parallel. The plate cylinder 14 is supported rotatably with the anilox roll 12 and the printing plate 14a in contact with each other. The plate cylinder 14 is connected to a drive motor (not shown) and can rotate in the direction of arrow B. The plate cylinder 14 transfers printing ink I from the anilox roll 12 to the printing plate 14a of the plate cylinder 14 while rotating. The outer diameter of the plate cylinder 14 is formed larger than the outer diameter of the anilox roll 12. The plate cylinder 14 is configured to be paired with a receiving roll 15, and the cut sheet S is transported between the plate cylinder 14 and the receiving roll 15 in the transport direction T, and the printing ink I is transferred to the cut sheet S as a print by passing through the pair of transport rolls 16. The printed cut sheet S is then transported to a post-process by a pair of transport rolls 16.

[0031] The printing process of printing devices 10a and 10b of printing device 10 is as described above, and the printing process of printing device 10c is the same as the printing process of printing devices 10a and 10b and is as described above, except that printing ink I is replaced with an antibacterial and antiviral agent.

[0032] In this embodiment, printing is performed on the cut sheet S using a flexographic printing device having the configuration described above, but the present invention is not limited to this, and printing may be performed on the cut sheet S using a flexographic printing device having a configuration other than that described above. Furthermore, other printing methods (gravure printing, inkjet printing, offset printing, etc.) are also acceptable as long as they achieve the effects of the present invention.

[0033] <Selection of printing ink> 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. In this embodiment, the present experiment was performed using a method in which a pattern was printed on a cut sheet S by the printing devices 10a and 10b, and an antibacterial and antiviral agent was printed on the cut sheet S by the printing device 10c.

[0034] FIG. 6 is a table showing the results of comparing the type of printing ink printed on the cut sheet S of the corrugated board according to the present invention and the antibacterial activity value. The results are the results of measuring the antibacterial activity value when the printing order and the type of printing ink are changed. That is, the table in FIG. 6 shows the printing order, the type of printing ink used in the printing devices 10a and 10b (normal, quick-drying, water-resistant), the ratio of the application amount of the antibacterial / antiviral agent to the printing ink (hereinafter also referred to as the ink application amount ratio), and the ratio of the viscosity (#4 Zahn cup viscosity) of the antibacterial / antiviral agent to the printing ink (hereinafter also referred to as the ink viscosity ratio), and each is evaluated as having an antibacterial / antiviral effect if the antibacterial activity value (based on JIS Z 2801) is 2 or more. The antibacterial and antiviral agent in this example is a paint having antibacterial and antiviral functions, which is prepared by adding silver ions supported on an inorganic substance as a substance having antibacterial and antiviral functions to a vehicle (alkali-soluble resin, emulsion resin, alkaline component, water, etc.) and various auxiliary agents (dispersants, crosslinking agents, defoamers, etc.). The viscosity of the antibacterial and antiviral agent is adjusted to a #4 Zahn cup viscosity of 10 to 13 seconds.

[0035] In Example 1, printing was performed with printing ink 1 and printing ink 2, and then printing was performed with the antibacterial and antiviral agent. The types of printing ink 1 and printing ink 2 were normal, and Wasser Super Z (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amounts was 1.2, and the ratio of the ink viscosities was 1.2. The antibacterial activity value was 3. From these results, it was recognized that the antibacterial and antiviral agent penetrated into the printing inks before printing ink 1 and printing ink 2 dried, and therefore there was some antibacterial and antiviral effect.

[0036] In Example 2, printing was performed with printing ink 1 and printing ink 2, and then printing was performed with the antibacterial and antiviral agent. Printing ink 1 and printing ink 2 were fast-drying printing inks, and Wasser Super Z SS (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amount was 1.2, and the ratio of the ink viscosity was 1.2. The antibacterial activity value was 4. From these results, it was determined that the antibacterial and antiviral agent did not penetrate into printing ink 1 and printing ink 2, and therefore had antibacterial and antiviral effects.

[0037] In Example 3, printing was performed with printing ink 1 and printing ink 2, and then printing with the antibacterial and antiviral agent. Printing ink 1 and printing ink 2 were water-resistant printing inks, and Wasser Super ZR (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amount was 1.2, and the ratio of the ink viscosity was 1.2. The antibacterial activity value was 4. From these results, it was determined that the antibacterial and antiviral agent did not penetrate into printing ink 1 and printing ink 2, and therefore had antibacterial and antiviral effects.

[0038] In Example 4, printing was performed with printing ink 1 and printing ink 2, and then printing with an antibacterial and antiviral agent. Printing ink 1 and printing ink 2 were fast-drying printing inks, and Wasser Super Z SS (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amount was 1.2, and the ratio of the ink viscosity was 0.8. The antibacterial activity value was 3. From these results, it was found that by slightly lowering the viscosity of printing ink 1 and printing ink 2, the antibacterial and antiviral agent penetrated into printing ink 1 and printing ink 2, and therefore there was some antibacterial and antiviral effect.

[0039] In Example 5, printing was performed with printing ink 1 and printing ink 2, and then printing was performed with the antibacterial and antiviral agent. Printing ink 1 and printing ink 2 were fast-drying printing inks, and Wasser Super Z SS (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amount was 1.5, and the ratio of the ink viscosity was 1.2. The antibacterial activity value was 5. From these results, it was determined that the antibacterial and antiviral agent had antibacterial and antiviral effects because it did not permeate into printing ink 1 and printing ink 2.

[0040] In Comparative Example 1, printing was performed with the antibacterial and antiviral agent, and then printing was performed with printing ink 1 and printing ink 2. The types of printing ink 1 and printing ink 2 were normal, and Wasser Super Z (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amounts was 1.2, and the ratio of the ink viscosities was 1.2. The antibacterial activity value was 1. From this result, it can be seen that the antibacterial and antiviral agent was ranked higher than printing ink 1 and printing ink 2, and therefore no antibacterial and antiviral effect was observed.

[0041] In Comparative Example 2, printing was performed with printing ink 1 and printing ink 2, and then printing was performed with the antibacterial and antiviral agent. The types of printing ink 1 and printing ink 2 were normal, and Wasser Super Z (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amounts was 0.5, and the ratio of the ink viscosities was 1.2. The antibacterial activity value was 1. From this result, it can be seen that the antibacterial and antiviral agent was ranked higher than printing ink 1 and printing ink 2, and therefore no antibacterial and antiviral effect was observed.

[0042] In Comparative Example 3, printing was performed with printing ink 1 and printing ink 2, and then printing with the antibacterial and antiviral agent. The types of printing ink 1 and printing ink 2 were normal, and Wasser Super Z (Osaka Printing Ink Mfg. Co., Ltd.) was used. The ratio of the ink application amounts was 1.2, and the ratio of the ink viscosities was 0.5. The antibacterial activity value was 1. From these results, it can be seen that the antibacterial and antiviral agent was ranked higher than printing ink 1 and printing ink 2, and therefore no antibacterial and antiviral effect was observed.

[0043] In this way, by printing with printing ink 1 and printing ink 2, then printing with the antibacterial and antiviral agent and using a quick-drying or water-resistant printing ink, it is possible to obtain antibacterial and antiviral effects without the antibacterial and antiviral agent penetrating the printing ink.

[0044] In the above, in order to express the contents of the present invention, the preferred embodiment of the present invention has been described with reference to the drawings. However, the present invention is not limited to the above embodiment, and includes modifications and improvements that are obvious to those skilled in the art based on the matters described in this specification. [Explanation of symbols]

[0045] 10a Printing device 10b Printing device 10c printing device Ia Printing ink layer Ib Printing ink layer Ic Antibacterial and Antiviral Layer

Claims

1. A corrugated board having a printed ink layer formed by printing ink and an antibacterial / antiviral layer formed by coating the printed ink layer with an antibacterial / antiviral agent, The cardboard has an average coating amount of the printing ink layer in a printed portion that is less than an average coating amount of the antibacterial and antiviral layer, The cardboard board, characterized in that the Zahn cup viscosity of the printing ink is lower than the Zahn cup viscosity of the antibacterial and antiviral agent.

2. 2. The cardboard according to claim 1, wherein the printing ink is a quick-drying printing ink.

3. 3. The cardboard according to claim 1, wherein the printing ink is a waterproof printing ink.

4. An antibacterial and antiviral corrugated board processing method having multiple printing devices in one printing process, (a) printing on the surface of the cardboard with printing ink by the printing device; (b) a step of printing an antibacterial and antiviral agent on a surface of the cardboard by the printing device, and the step (b) is carried out after the step (a), 1. An antibacterial and antiviral cardboard processing method, wherein the Zahn cup viscosity of the printing ink used in the step (a) is lower than the Zahn cup viscosity of the antibacterial and antiviral agent used in the step (b).

5. The antibacterial and antiviral corrugated board processing method according to claim 4, characterized in that the average application amount of the printing ink in the step (a) is less than the average application amount of the antibacterial and antiviral agent in the step (b).

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