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JP-2026074770-A - Manufacturing methods for printed materials

JP2026074770AJP 2026074770 AJP2026074770 AJP 2026074770AJP-2026074770-A

Abstract

[Problem] To provide a method for manufacturing printed materials having two or more printing layers that suppresses deterioration and discoloration of the substrate due to electron beam irradiation, can achieve a wide range of colors, and has excellent productivity. [Solution] A method for manufacturing a printed material having a first printed layer and a second printed layer sequentially on a substrate, comprising: step 1 applying one or more active energy ray curable offset printing inks to the surface of the substrate to form a first ink coating; step 2 applying one or more active energy ray curable flexographic printing inks to the surface of the substrate on which the first ink coating obtained in step 1 is formed to form a second ink coating; and step 3 after step 2 irradiating with an electron beam to simultaneously cure the first ink coating and the second ink coating to form a first printed layer made of the cured product of the first ink coating and a second printed layer made of the cured product of the second ink coating. [Selection Diagram] None

Inventors

  • 末永 隼也
  • 武井 希

Assignees

  • ａｒｔｉｅｎｃｅ株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (12)

  1. A method for manufacturing a printed material having a first printed layer and a second printed layer sequentially on a substrate, Step 1 involves applying one or more active energy ray-curable offset printing inks to the surface of a substrate to form a first ink coating, Step 2 involves applying one or more active energy ray curable flexographic printing inks to the surface of the substrate on which the first ink coating obtained in step 1 is formed, thereby forming a second ink coating. A method for manufacturing a printed material, comprising: step 2 above, step 3, in which an electron beam is irradiated to simultaneously cure the first ink coating and the second ink coating, thereby forming a first printed layer consisting of the cured first ink coating and a second printed layer consisting of the cured second ink coating.
  2. The method for manufacturing a printed material according to claim 1, wherein in step 3, the acceleration voltage of the electron beam is 50 to 250 kV.
  3. The method for manufacturing a printed material according to claim 1, wherein in step 3, the irradiation dose of the electron beam is 10 to 60 kGy.
  4. A method for manufacturing a printed material according to claim 1, wherein the printing speed is 50 to 300 m/min.
  5. A method for manufacturing a printed material according to claim 1, wherein the step between step 1 and step 2 is not to include a step of irradiating with an active energy ray to cure the active energy ray-curable offset printing ink.
  6. The method for producing a printed article according to claim 1, wherein the active energy ray-curable offset printing ink comprises a resin, a polyfunctional (meth)acrylate, and a colorant.
  7. The method for manufacturing a printed article according to claim 1, wherein the active energy ray-curable flexographic printing ink includes an active energy ray-curable white flexographic printing ink.
  8. The method for manufacturing a printed article according to claim 1, wherein the active energy ray-curable flexographic printing ink includes an active energy ray-curable flexographic printing varnish.
  9. The method for manufacturing a printed article according to claim 1, wherein the substrate is a paper substrate or a transparent film substrate.
  10. The method for manufacturing a printed material according to claim 9, wherein the thickness of the paper substrate is 50 μm to 150 μm.
  11. The method for manufacturing a printed material according to claim 9, wherein the thickness of the transparent film substrate is 1 μm to 35 μm.
  12. A method for manufacturing a printed material according to claim 1, wherein the printed material is used as packaging material.

Description

Embodiments of the present invention relate to a method for manufacturing printed materials. Packaging materials, primarily used in the food and consumer goods sectors, are expected to see continued growth in demand due to global population increase. Currently, gravure printing is the dominant method for printing flexible packaging materials. Gravure printing produces visually vibrant printed materials. However, because gravure printing uses inks containing large amounts of solvent, it requires a large amount of energy for drying the ink solvents and treating the exhaust fumes, resulting in a significant environmental impact. Furthermore, recent market needs have shifted from traditional mass production and mass consumption to small lots, diverse product ranges, and short delivery times. In contrast, gravure printing is a printing method suitable for large-lot printing, and its plate and plate-making costs are high, resulting in higher production costs for printed materials. For this reason, offset printing, which has lower plate and plate-making costs, is easier to handle for small lots and short delivery times, and offers cost advantages for printed materials, has been attracting attention in recent years. Offset printing is a widely used printing method that provides high-speed, high-volume, and inexpensive printed materials. The inks used can be either solvent-based or non-solvent-based. In recent years, from the perspective of environmental concerns and carbon neutrality, active energy ray-curable inks, which harden instantly upon irradiation with active energy rays, have attracted attention, and research into offset printing using such inks is progressing. In the manufacturing of packaging materials used in the food and consumer goods sectors, the printing process is generally carried out using high-speed roll-to-roll printing. From the perspective of increasing productivity in the above printing process, the quick-drying properties of the ink are crucial. Therefore, offset printing using active energy ray-curable inks is expected to be effective in the manufacturing of printed materials used for packaging. For example, Patent Document 1 discloses a method for manufacturing packaging materials that includes a step of printing ultraviolet-curable or electron beam-curable ink onto paper or plastic film using offset printing. In recent years, among active energy ray curing inks, UV-curing inks containing photopolymerization initiators and curing systems for UV-curing inks have become the mainstream in the market. UV-curing inks do not contain volatile components and cure instantly upon irradiation with UV energy rays. Therefore, they allow for a shortened drying process without the use of thermal energy, offering environmental advantages as well as energy savings and high productivity. However, for packaging materials used in the food and consumer goods sectors, the addition of photopolymerization initiators to inks is undesirable from the perspective of preventing contamination of contents due to migration, etc. Therefore, as a curing method using active energy rays that does not contain photopolymerization initiators, the expansion of electron beam curing methods that do not require photopolymerization initiators is expected. Furthermore, when forming a multilayer printed material having two or more printing layers on a substrate using an active energy ray-curable ink, a common method involves first applying and curing the ink on the substrate to form a first printing layer, and then applying and curing the ink on top of the first printing layer (which consists of cured ink) to form a second printing layer. For example, Patent Document 2 discloses a printing method using an offset printing press, in which UV (ultraviolet) curable ink is applied to the substrate, cured by UV irradiation, and then printed as a post-processing step, such as screen printing or flexographic printing. However, the method of curing the ink each time it is applied is desirable from the standpoint of production efficiency. Japanese Patent Publication No. 2004-358788International Public Gazette 2014/083722 The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and includes embodiments that are implemented without changing the essence of the invention. One embodiment of the present invention relates to a method for manufacturing a printed material having a first printed layer and a second printed layer sequentially on a substrate. The method for manufacturing the printed material according to this embodiment includes a printing step of sequentially applying an active energy ray-curable offset printing ink and an active energy ray-curable flexographic printing ink to the surface of a substrate, and a curing step of irradiating the ink coating film obtained in the printing step, which has the configuration of substrate/active ener