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CN-115870191-B - Method for producing a mechanically stable coating containing a colorant

CN115870191BCN 115870191 BCN115870191 BCN 115870191BCN-115870191-B

Abstract

A method for producing a coating having at least one colorant enriched at an interface, preferably a floating pigment, is described, comprising the steps of providing a hardenable liquid medium comprising at least one colorant enriched at an interface, applying the hardenable liquid medium to a carrier, wherein the colorant enriched at an interface is enriched at an interface of the hardenable liquid medium and an ambient atmosphere, at least partially hardening the hardenable liquid medium on the carrier, and transferring the at least partially hardened hardenable liquid medium from the carrier to a substrate, such that the colorant enriched at an interface is applied against the substrate on the side of the carrier enriched at the interface.

Inventors

  • M. Schmidt-Levin

Assignees

  • 海德堡印刷机械股份公司

Dates

Publication Date
20260512
Application Date
20220809
Priority Date
20210928

Claims (11)

  1. 1. A method for producing a coating having at least one colorant enriched at an interface, the method comprising the steps of: i) Providing a hardenable liquid medium comprising at least one colorant enriched at an interface; ii) applying the hardenable liquid medium to a support, wherein the colorant enriched at the interface is enriched at the interface of the hardenable liquid medium and the ambient atmosphere; iii) At least partially hardening the hardenable liquid medium on the carrier, and Iv) transferring the at least partially hardened hardenable liquid medium from the carrier onto a substrate such that the colorant enriched at the interface is brought into abutment against the substrate on the side enriched on the carrier.
  2. 2. The method according to claim 1, wherein the at least one colorant enriched at the interface is enriched in the hardenable liquid medium at the interface of the hardenable liquid medium with the surrounding atmosphere due to its lower density and/or its surface properties compared to the hardenable liquid medium.
  3. 3. The method according to claim 1 or 2, wherein the at least one colorant enriched at the interface is at least one effect pigment.
  4. 4. The method according to claim 1 or 2, wherein the at least one colorant enriched at the interface is at least one inorganic metallic effect pigment.
  5. 5. The method of claim 1 or 2, wherein the at least one colorant enriched at the interface is at least one leafing pigment.
  6. 6. A method according to claim 1 or 2, wherein the hardenable liquid medium is substantially transparent.
  7. 7. A method according to claim 1 or 2, wherein the method is carried out with a printing press.
  8. 8. The method of claim 7, wherein the carrier is a cylinder of a printing press.
  9. 9. The method according to claim 1 or 2, wherein the hardenable liquid medium comprising at least one colorant enriched at the interface is a printing ink or a printing varnish.
  10. 10. A method according to claim 1 or 2, wherein the substrate is selected from paper, cardboard and plastic foil.
  11. 11. The method according to claim 1 or 2, comprising the steps of: i) Providing a hardenable printing ink or hardenable printing varnish comprising at least one leafing pigment; ii) applying the hardenable printing ink or hardenable printing varnish to a cylinder or plate of a printing press, wherein the leafing pigment is enriched at the interface of the hardenable printing ink or hardenable printing varnish and the surrounding ambient atmosphere; iii) At least partially hardening the hardenable printing ink or hardenable printing varnish on a cylinder or plate of the printing press, and Iv) transferring the at least partially hardened curable printing ink or curable printing varnish from the cylinder or plate of the printing press onto the printing material, so that the floating pigment is brought into contact with the printing material on the side of the cylinder or plate of the printing press that is enriched.

Description

Method for producing a mechanically stable coating containing a colorant Technical Field The present invention relates to a method for producing a coating having at least one colorant enriched at the interface, and to the use of the method for producing an abrasion-resistant coating containing such a colorant. The invention also relates to a printed matter obtained by the method of the invention. Background Different methods are disclosed in the printing industry for providing prints with visually attractive metallic gloss coatings. It is common practice, for example, to glue glossy foils by the foil transfer printing method. Another known possibility is to print pigment-containing printing inks or printing varnishes directly onto the printing material, wherein the printed printing material is then hardened in a printing press. Printing methods known for this purpose are, for example, offset printing. Printing inks and printing gloss oils containing effect pigments are disclosed in the prior art. Printing inks and printing gloss oils with leafing or leafing pigments (English: LEAFING PIGMENTS) and Non-leafing or Non-leafing pigments (English: non-LEAFING PIGMENTS) are distinguished in principle here. In general, printing inks and printing gloss oils with leafing pigments are considered to be the most visually attractive class of metallic effects. Thus, silver printing glosses containing aluminum-based leafing pigments are popular. Such leafing pigments are described, for example, in German industry standard DIN 55923. In contrast, while printing inks and printing gloss oils based on non-leafing pigments are also becoming more and more widespread, they generally exhibit a metallic effect that is less visually attractive and tend to appear rather matt and dull. Printing inks and printing gloss based on leafing pigments, while exhibiting excellent metallic effects, have important drawbacks. They have problems with respect to mechanical robustness, in particular with respect to scratch sensitivity and abrasion resistance. Because the leafing pigment is just below the surface, such coatings are sensitive and must generally be protected from mechanical abrasion by one or more varnish layers disposed thereon. However, the application of such an additional protective layer is costly and uneconomical. In contrast, coatings based on printing inks and printing gloss oils with non-leafing pigments are generally less sensitive, since the pigments therein are substantially uniformly distributed. Here, an additional protective layer is generally not required. There is a need for efficient methods by which mechanically robust coatings with leafing pigments can be produced. Thus, there is a need in the printing industry to be able to efficiently produce such mechanically robust coatings in printing presses. EP 3 165,578 a1 describes a metallic offset printing ink with specular gloss and a printing method. The abrasion stability of the aluminum pigment should be achieved by the printed layer. WO 2008/052645 A2 describes a finishing process and a coating unit for printed products. In this method, the liquid printing medium is applied to a carrier in a printing press, dried there and transferred to a substrate. Disclosure of Invention The object of the present invention is to provide a method by means of which mechanically stable coatings with floating pigments can be produced with high efficiency. The method is particularly suitable for enabling the production of coated prints in a printing press. It has now surprisingly been found that mechanically stable coatings with leafing pigments can be produced relatively simply by first applying a hardenable liquid medium comprising leafing pigments to a carrier, drying there and then joining the substrate to be coated as a film with the side enriched with leafing pigments. By doing so, the sensitive leafing pigment is kept away from the outer surface of the coated substrate and protected by the hardened layer thereon. The method of the present invention has many advantages. There is no longer a need to apply one or more protective layers. No longer needs to ensure pigment-containing layers and the protective layer are compatible with each other. The method can be carried out continuously in a printing press and is compatible with common printing inks and printing varnishes and printing materials. Accordingly, the present invention relates to a method for producing a coating having at least one colorant enriched at the interface, comprising the steps of: i) Providing a hardenable liquid medium comprising at least one colorant enriched at an interface; ii) applying the hardenable liquid medium to a support, wherein the colorant enriched at the interface is enriched at the interface between the hardenable liquid medium and the ambient atmosphere; iii) At least partially hardening the hardenable liquid medium on the carrier, and Iv) transferring the at least partially hardened hardenabl