JP2005068570A - Gravure printing paperboard and printed product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide gravure printing paper board which is printed by a gravure rotary printing style using an electrostatic printing method and has reproducibility for not only excellent patterns all over but also excellent harmony, to provide a printed product which is obtained by printing gravure printing paper board by the gravure rotary printing style using the electrostatic printing method, thus removing electrostaticity from the charged printed product. <P>SOLUTION: This gravure printing paper board having a coating layer on at least one side and having a basis weight of 200 to 700 g/cm<SP>2</SP>is characterized by having volume electric resistivity of ≥1.0×10<SP>13</SP>Ωcm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gravure printing board which is used for a paper box or the like for packaging foods, cosmetics, cigarettes, etc., and a printed matter using the same.

  Conventionally, it is possible to obtain a printed pattern with good gradation reproducibility and volume, or a wide choice of binders and printing on various printing materials (printing sheets). Therefore, the gravure rotary printing method is widely adopted.

  The gravure rotary printing method usually uses a gravure plate in which cells (recesses) that represent patterns and characters are provided on the peripheral surface of a cylindrical cylinder, and these cells are filled with printing ink to produce a printing material (printing material) Sheet) is passed between the gravure plate and the impression cylinder so that the printing ink filled in the cells is transferred to the printing material (printing sheet), and the print material (printing sheet) has a pattern or This is a printing method that reproduces characters.

However, paper used for a paper box or the like for storing contents such as food, cosmetics, and cigarettes is required to retain its shape from the necessity of protecting the contents, and usually has a basis weight of 200. -700 g / m ² paperboard is used, but this paperboard is not smooth (it has surface irregularities), and the density of the paper is not uniform and the cushioning property is uneven, etc. There is a problem that the reproducibility of the ink is poor (the printing ink transfer varies).

  As one means for solving the above problem, an electrostatic printing method using static electricity is adopted to facilitate transfer of printing ink from a cell provided in a gravure plate to a printing material (printing sheet). Yes. In this electrostatic printing method, a voltage is applied between the gravure plate and the impression cylinder to generate an electric field in this portion, thereby charging the printing ink in the cell and transferring the printing ink from the cell to the printing material (printing sheet). This is a printing method that facilitates transfer of printing ink from the inside of the cell to the printing material (printing sheet).

  However, the gravure rotary printing method using this electrostatic printing method is satisfactory, although the reproducibility of gradation, especially light gradation, is improved compared to the conventional gravure rotary printing method not using electrostatic printing method. In addition, it was found that the degree of improvement in reproducibility of gradation, particularly light gradation, differs depending on the type of paperboard (by paper manufacturer). The present inventors completed the present invention by investigating the difference in the reproducibility of gradation reproducibility and finding that there is a correlation between the volume electrical resistivity of the paperboard and the improvement.

  Although there are various prior art documents disclosing the technical background of the gravure rotary printing method using the electrostatic printing method, the applicant has not directly described the contents directly related to the features of the present invention, that is, the electrostatic printing method. Since the prior art document disclosing the paperboard used for the gravure rotary printing system used is not recognized at this stage, the prior art document information is not described in this specification.

  Accordingly, a first problem of the present invention is a gravure printing board which is printed by a gravure rotary printing method using an electrostatic printing method, and is a gravure printing board which has a solid pattern and excellent gradation reproducibility. The second problem is to provide a printed matter in which static electricity is gradually reduced from a printed matter charged by printing with the gravure rotary printing method using the electrostatic printing method using the gravure printing board. That is.

In order to achieve the above object, the inventors of the present invention are the gravure printing paperboard having a basis weight of 200 to 700 g / m ² and having a coating layer on at least one surface. A gravure printing board having a volume electrical resistivity of 1.0 × 10 ¹³ Ωcm or more.

  The invention according to claim 2 is the gravure printing board according to claim 1, wherein the coating layer is an organic pigment-containing layer containing an organic pigment.

  Further, the present invention according to claim 3 is the paperboard for gravure printing according to claim 2, wherein the organic pigment-containing layer comprises 5 to 100% by mass of an organic pigment and 95 to 0% by mass of an inorganic pigment as pigment components. It is characterized by being a layer to be formed.

  According to a fourth aspect of the present invention, there is provided the gravure printing board according to the second or third aspect, wherein the organic pigment is one or more of polystyrene, benzoguanamine, silicone, polytetrafluoroethylene, and polymethyl methacrylate. It is characterized by two or more kinds of fine beads.

  The present invention according to claim 5 is the gravure printing board according to claim 3, wherein the inorganic pigment is clay.

  The present invention according to claim 6 is the gravure printing board according to claim 1, characterized in that a resin coating layer is provided on the surface of the coating layer.

  The present invention according to claim 7 is the gravure printing board according to claim 6, wherein the resin coating layer is a layer mainly composed of chlorinated polypropylene.

  The present invention according to claim 8 is the gravure printing board according to claim 6, wherein the resin coating layer is a layer mainly composed of polymethyl methacrylate.

The printed matter of the present invention according to claim 9 is equipped with an electrostatic printing device on the surface of the coating layer of the paper for gravure printing using the paper for gravure printing according to any of claims 1 to 8. After printing a printed pattern with a gravure rotary printing machine, an overprint layer is formed with a colorless and transparent printing ink to which an antistatic agent is added at least in a portion corresponding to the printed pattern, and the volume resistivity is 1.0 ×. It is characterized by being less than 10 ¹⁶ Ωcm.

The gravure printing board of the present invention is printed by a gravure rotary printing method using an electrostatic printing method by adopting a configuration in which the volume electrical resistivity of the gravure printing paper board is 1.0 × 10 ¹³ Ωcm or more. As a result, the solid pattern has an effect that the reproducibility of gradation is excellent as well as the original. In addition, using the gravure printing paperboard of the present invention, after printing a printed pattern with a gravure rotary printing machine equipped with an electrostatic printing device on the coating layer surface of the gravure printing paperboard, at least corresponding to the printed pattern By forming the overprint layer with a colorless and transparent printing ink with an antistatic agent added to the part, the static electricity charged by the electrostatic printing device is gradually reduced, and the volume resistivity is 1.0 × 10 ^16. There is an excellent effect that it is possible to obtain a printed material of less than Ωcm.

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a diagram schematically showing an embodiment of a layer configuration of a gravure printing paperboard according to the present invention, and FIG. 2 is a diagram schematically showing another embodiment of a layer configuration of a gravure printing paperboard according to the present invention. FIG. 3 is a view schematically showing an embodiment of a layer structure of a printed matter using the gravure printing board according to the present invention, in which 1 and 1 ′ are gravure printing board and 2 is a coated paper. 2 ′ is a paper layer, 2 ″ and 2 ′ ″ are coating layers, 3 is a resin coating layer, 4 is a printed picture layer, 5 is an overcoat layer (OP layer), and 10 is a printed matter.

  FIG. 1 is a diagram schematically showing an embodiment of a layer structure of a gravure printing paperboard according to the present invention. The gravure printing paperboard 1 is a coating in which a coating layer 2 ″ is formed on a paper layer 2 ′. A resin coating layer 3 is formed on the coating layer 2 ″ of the paper 2.

As the coated paper 2, a paperboard marketed by a paper manufacturer can be used. For example, CRC [manufactured by Rengo Co., Ltd .: trade name], Maricoat [manufactured by Hokuetsu Paper Co., Ltd .: trade name], Mach Ball [Ide Paper Co., Ltd .: trade name], Suncoat [Oji Paperboard Co., Ltd .: trade name], OK Ball [Oji Paper Co., Ltd .: trade name], JET Star [Japan Daishowa Paperboard Yoshinaga ( Co., Ltd .: product name] can be used, and the basis weight is not particularly limited as long as the basis weight does not impair the appearance of the paper box. For example, the basis weight is 200 to 700 g / m ^2. Is appropriate.

As the coating film resin layer 3, the coating resin layer is used so that the volume electric resistivity of the gravure printing paperboard 1 is 1.0 × 10 ¹³ Ωcm or more, preferably 1.0 × 10 ¹⁴ Ωcm or more. The thickness of the coating film may be determined appropriately depending on the type of resin that forms 3. When the volume electrical resistivity of the gravure printing paper board 1 is less than 1.0 × 10 ¹³ Ωcm, even if printing is performed by a gravure rotary printing method using an electrostatic printing method, gradation reproducibility is poor. Further, the upper limit of the volume electrical resistivity is not particularly limited as long as it is a resistivity that does not cause problems such as printability inhibition due to electrostatic charging, for example, adhesion of printing ink to non-image areas, Aside from providing an overprint layer for gradually eliminating static electricity described later, the sheet is cut into a sheet to be printed after printing by setting it to less than 2.0 × 10 ¹⁶ Ωcm, preferably less than 1.0 × 10 ¹⁶ Ωcm. In the process and / or the process of punching into a developed shape (blank) of a paper box, it is possible to prevent the problem that the sheets and / or blanks become uneven due to electrostatic charging and are difficult to handle. The resin for forming the coating film resin layer 3 is a resin that has a specific volume resistivity of 1.0 × 10 ¹³ Ωcm or more, preferably 1.0 × 10 ¹⁴ Ωcm or more. For example, one or more of chlorinated polyolefin resin, acrylic resin, polyamide resin, polystyrene resin, fluorine resin, etc. can be used, but printing such as drying and trapping is possible. Chlorinated polypropylene and polymethyl methacrylate are preferred for reasons such as suitability and electrical characteristics (mainly volumetric electrical resistivity). The thickness of the coating film resin layer 3 may be appropriately determined from the volume electrical resistivity of the coated paper 2 itself and the volume electrical resistivity of the resin species forming the coating film resin layer 3, A coating amount of approximately 1.0 to 5.0 g / m ² is appropriate after drying.

FIG. 2 is a view schematically showing another embodiment of the layer constitution of the gravure printing paperboard according to the present invention. The gravure printing paperboard 1 ′ has an organic pigment 5 as a pigment component on the paper layer 2 ′. A coating layer 2 ′ ″ composed of ˜100% by mass and 0 to 95% by mass of an inorganic pigment is provided. The organic pigment is added so that the volume electrical resistivity of the gravure printing paperboard 1 ′ is 1.0 × 10 ¹³ Ωcm or more, preferably 1.0 × 10 ¹⁴ Ωcm, for the reason described above. Yes, the blending ratio may be appropriately determined depending on the type of organic pigment. Examples of the organic pigments include fine beads such as polystyrene, benzoguanamine, silicone, polytetrafluoroethylene, and polymethyl methacrylate, and considering the ease of liquefaction and uniform dispersion, the average particle size is: A spherical bead of 0.1 to 1.0 μm is suitable, and one or more kinds can be used. The organic pigment is more expensive than the inorganic pigment, but it is necessary to add the organic pigment so that the ratio of the organic pigment to the total pigment is 5% by mass or more from the necessity of obtaining the volume electric resistivity described above. is there. The coating layer 2 ″ ′ is formed by applying an aqueous dispersion to which a known additive such as a binder and a dispersant is added in addition to the pigment. The coating amount of the coating layer 2 ′ ″ after the calendar process is approximately 10 to 20 g / m ² . 1 and 2, the paper layer 2 ′ may be a single layer, but usually has a multilayer structure.

FIG. 3 is a diagram schematically showing an example of a layer structure of a printed matter using the gravure printing paperboard according to the present invention. The printed material 10 is the coating resin of the gravure printing paperboard 1 shown in FIG. After the printed pattern is printed on the layer 3 by a gravure rotary press equipped with an electrostatic printing device, the printed pattern layer 4 is provided, and then at least a portion corresponding to the printed pattern layer 4 is added with an antistatic agent. The overprint layer (OP layer) 5 is formed with the printing ink. With this configuration, the printed material 10 can be a printed material in which the charged static electricity is gradually reduced by providing the OP layer. The volume electrical resistivity of the printed product 10 needs to be less than 2.0 × 10 ¹⁶ Ωcm, preferably less than 1.0 × 10 ¹⁶ Ωcm, considering the post-processing suitability described above. The OP layer 5 is generally provided on a portion that becomes an exposed surface when, for example, a paper box is used.

  The printing ink for forming the printed pattern layer 4 needs to adhere well to the coating film resin layer 3, and the printing ink vehicle needs to be appropriately selected depending on the type of resin forming the coating film resin layer 3. However, as the vehicle, resins such as acrylic, polyester, polyamide, polyurethane, cellulose, rubber, urea, melamine, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, chlorinated polypropylene One or two or more of these can be used as a mixture, and pigments, solvents, various adjuvants, etc. can be added to make them into inks. Acrylic resin is preferable.

Further, the printing ink for forming the OP layer 5 needs to adhere well to the coating resin layer 3 and the printed pattern layer 4, and the same vehicle as that for forming the printed pattern layer 4 is appropriate. The ink is made by adding a solvent, various auxiliary agents and the like. Antistatic agents added to the printing ink forming the OP layer 5 include nonionic, alkyl sulfonates, alkyl benzene sulfonates such as glycerin fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkyl amines, etc. , Well known surfactants such as anionics such as alkyl sulfates and alkyl phosphates, cationic systems such as tetraalkylammonium salts and trialkylbenzylammonium salts, and amphoteric systems such as alkylbetaines and imidazolines. The amount is suitably about 0.3 to 2.0 parts by mass with respect to 100 parts by mass of printing ink. The coating amount after drying the OP layer 5 is suitably 1.0 to 5.0 g / m ² .

Next, a test conducted for completing the present invention will be described.
[Test 1]
310g / m ² OK ball [Oji Paper Co., Ltd .: trade name, volumetric electrical resistivity: 2.6 × 10 ¹² Ωcm] coated surface with gravure rotary printing 8-color machine [Bobst Chan Plain (Switzerland) The ink was printed with water-based acrylic ink [The Inktec Co., Ltd .: Ode HIPAC (trade name)] and punched in-line to obtain a multi-colored printed matter.

[Test 2]
Each unit that prints a halftone of a gravure rotary printing press was equipped with an electrostatic printing device and operated to perform printing in the same manner as in Test 1 and punching to obtain a multicolored printed matter with color tone.

[Test 3]
Printing and punching in the same manner as in Test 1 except that 310 g / m ² CRC [manufactured by Rengo Co., Ltd .: trade name, volume electrical resistivity: 1.7 × 10 ¹³ Ωcm] was used instead of the OK ball. To obtain a multi-color printed matter of color tone.

[Test 4]
Each unit that prints a halftone of a gravure rotary printing press was equipped with an electrostatic printing device and operated to perform printing in the same manner as in Test 3 and punching to obtain a multi-colored printed matter with color tone.

[Test 5]
Oil-based acrylic primer [manufactured by Showa Ink Co., Ltd .: Primer ACR (trade name)] is dried on the coated surface of 310 g / m ² OK ball instead of OK ball, and becomes 1.3 to 1.5 g / m ² after drying. In this way, printing was performed in the same manner as in Test 2 except that a solid-printed one (volume electrical resistivity: 5.5 × 10 ¹⁴ Ωcm) was used, and punching was performed to obtain a multicolored printed matter having a color tone.

[Test 6]
Instead of oil-based acrylic medium, chlorinated polypropylene primer [Showa Ink Co., Ltd .: Primer POR (trade name)] was dried and solid-printed to 1.3-1.5 g / m ² after drying. Except for using the obtained one (volume electrical resistivity: 1.9 × 10 ¹⁴ Ωcm), printing was performed in the same manner as in Test 5, and punching was performed to obtain a multicolored printed matter in color tone.

[Test 7]
Instead of the oil-based acrylic medium, a nitrified cotton-based primer [Showa Ink Co., Ltd .: Corrugated NT (trade name)] was solid-printed so as to be 1.3 to 1.5 g / m ² after drying. Except for using a material (volume electrical resistivity: 2.0 × 10 ¹³ Ωcm), printing was performed in the same manner as in Test 5, and punching was performed to obtain a multicolored printed matter in color tone.

[Test 8]
Instead of CRC, an oily acrylic primer [manufactured by Showa Ink Co., Ltd .: Primer ACR (trade name)] is dried on a coated surface of 310 g / m ² CRC so as to be 1.3 to 1.5 g / m ² after drying. Printing was performed in the same manner as in Test 3 except that a solid-printed one (volume electrical resistivity: 1.8 × 10 ¹⁶ Ωcm) was used, and a punching process was performed to obtain a multicolored printed matter having a color tone.

[Test 9]
Instead of oil-based acrylic medium, chlorinated polypropylene primer [Showa Ink Co., Ltd .: Primer POR (trade name)] was dried and solid-printed to 1.3-1.5 g / m ² after drying. Except for using the obtained one (volume electrical resistivity: 6.1 × 10 ¹⁵ Ωcm), printing was performed in the same manner as in Test 8, and punching was performed to obtain a multicolored printed matter with color tone.

[Test 10]
Instead of the oil-based acrylic medium, a nitrified cotton-based primer [Showa Ink Co., Ltd .: Corrugated NT (trade name)] was solid-printed so as to be 1.3 to 1.5 g / m ² after drying. Except for using the one (volume electrical resistivity: 6.1 × 10 ¹³ Ωcm), printing was performed in the same manner as in Test 8, and punching was performed to obtain a multicolored printed matter in color tone.

[Test 11]
8 colors of gravure rotary printing on corona discharge treated surface (polyethylene 17 μm surface) of double-sided polyethylene coated paper [Wear Hauser: polyethylene 17 μm / paper 313 g / m ² / polyethylene 54 μm, volume electrical resistivity: 1.3 × 10 ¹⁹ Ωcm] Using a machine [Bobst Chan Plain Co., Ltd. (Switzerland)], printing with nitrified cotton-urethane ink [The Inktec Co., Ltd .: L pack (trade name)] and in-line punching A multicolored printed matter of color tone was obtained. Each unit that prints halftones of a gravure rotary printing press was equipped with an electrostatic printing device and operated to perform printing.

  About the multi-color printed matter of the color tone of the above tests 1 to 11, the reproducibility of the halftone portion was evaluated, and a gray scale that reproduces up to a density of 20% is shown as a good level by ◯, % Is reproduced as a level where there is no problem in practical use, and it is evaluated as x indicated as defective when it is reproduced up to 50%, and the color after punching is evaluated. Table 1 shows the results of evaluating the suitability and inadequacy of the paper alignment of the multicolor printed matter.

As is clear from Table 1, the gravure printing board using the electrostatic printing apparatus has a volume resistivity of 1.0 × 10 ¹³ Ωcm or more and less than 2.0 × 10 ¹⁶ Ωcm, preferably 1.0 ×. The gravure printing paperboard having a density of 10 ¹⁴ Ωcm or more and less than 2.0 × 10 ¹⁶ Ωcm has a good half-tone thickness, and exhibits a remarkable effect that the paper does not become uneven in the post-processing.

In addition, after performing multicolor printing of color tone for test 11, the nitrified cotton-based ink to which 1.5% by mass of the glycerin fatty acid ester-based antistatic agent was added was dried in a printing unit before entering the punching process. Later, gravure printing was performed to 1.5 g / m ² to form an OP layer and punching was performed to obtain a color-colored multicolored print. Due to the effect of applying an antistatic agent, the multicolored printed We were able to arrange the papers in an orderly manner without any irregularities. In addition, the volume electrical resistivity of the multicolor printed material coated with the antistatic agent was 1.1 × 10 ¹⁶ Ωcm.

  The volume resistivity described in the present specification is a value measured by combining a digital super high resistance meter (type: R8340) manufactured by Advantest Co., Ltd. and a shield box (type: R12704A). Moreover, the electrostatic printing apparatus equipped in the gravure rotary printing press is Heliophone [manufactured by Spengler (Switzerland): trade name].

It is a figure which shows one Example of the laminated constitution of the paperboard for gravure printing concerning this invention illustratively. It is a figure showing other examples of layer composition of a paperboard for gravure printing concerning the present invention diagrammatically. It is a figure showing one example of layer composition of a printed matter using the paperboard for gravure printing concerning the present invention.

Explanation of symbols

1, 1 'Gravure printing board 2 Coated paper 2' Paper layer 2 ", 2 '" Coating layer 3 Resin coating layer 4 Printing pattern layer 5 Overcoat layer (OP layer)
10 Printed matter

Claims (9)

In gravure printing paperboard having a basis weight of 200 to 700 g / m ² having a coating layer on at least one surface, the volume electric resistivity of the gravure printing paperboard is 1.0 × 10 ¹³ Ωcm or more. Gravure printing board. 2. The paperboard for gravure printing according to claim 1, wherein the coating layer is an organic pigment-containing layer containing an organic pigment. The paperboard for gravure printing according to claim 2, wherein the organic pigment-containing layer is a layer composed of 5 to 100% by mass of an organic pigment and 95 to 0% by mass of an inorganic pigment as pigment components. 4. The gravure printing according to claim 2, wherein the organic pigment is one or more fine beads of polystyrene, benzoguanamine, silicone, polytetrafluoroethylene, and polymethyl methacrylate. Paperboard. The paperboard for gravure printing according to claim 3, wherein the inorganic pigment is clay. The paperboard for gravure printing according to claim 1, wherein a resin coating layer is provided on a surface layer of the coating layer. The paperboard for gravure printing according to claim 6, wherein the resin coating layer is a layer mainly composed of chlorinated polypropylene. 7. The paperboard for gravure printing according to claim 6, wherein the resin coating layer is a layer mainly composed of polymethyl methacrylate. Using the gravure printing paperboard according to any one of claims 1 to 8, after printing a printing pattern on a gravure rotary printing press equipped with an electrostatic printing device on the coating layer surface of the gravure printing paperboard, A printed matter, wherein an overprint layer is formed with a colorless and transparent printing ink to which an antistatic agent is added at least in a portion corresponding to the printed pattern, and a volume electrical resistivity is less than 1.0 × 10 ¹⁶ Ωcm.

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