CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application No. 18 181 138.1 filed Jul. 2, 2018, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to transfer media for transferring a functional active ingredient to a surface of an article by means of heat, to methods for preparing such transfer media and for providing a surface of an article with a functional active ingredient as well as to the use of such transfer media in different technical fields.

Technical Considerations It is often desirable to provide the surface of articles of various technical fields, such as clothing, furniture, glassware, sanitary items, electrical appliance, vehicles, etc., with a certain functional property such as abrasion-resistance, water-repellency, UV-resistance and/or anti-microbial properties. A common method for doing so is to incorporate a functional active ingredient providing said desired functional property into the base material prior to forming the article from said base material or to apply the functional active ingredient in form of a coherent layer to a surface of said article, e.g. as a paint, lacquer, another kind of coating or by means of an adhesive film or foil.

Depending on the intended use, both approaches suffer from several drawbacks. For instance, incorporating a functional active ingredient throughout the whole base material requires a rather high amount of said material leading to an increase in production costs. Moreover, compatibility problems can occur in the base material formulation, for example in polymerization reactions. In particular, this method is not suitable for modifying the properties of an already existing article and thus usually is not an option for e.g. an end user or consumer in the hobby sector.

The application of the active ingredient as a coherent coating often requires the use of organic solvents. Films and foils often are difficult to apply to curved or structured surfaces. In addition, flaking, chipping or peeling of such coherent layers, which are applied as a separate layer onto the surface of an article, often is a problem.

SUMMARY OF THE INVENTION

Thus, it is an object of the present invention to provide a simple process for furnishing the surface of an article with functional properties, such as abrasion resistance, scratch resistance, water repellency, UV resistance, electrical conductivity, electrical insulation, printability, weather resistance, oxidation resistance, non-stick/anti-adhesive properties, temperature resistance, oil-repellent properties, dirt-repellent properties and/or anti-microbial properties as well as to provide the means for carrying out such process.

This object is met by the transfer medium and methods of the present invention. The transfer medium for transferring a functional active ingredient to the surface of an article according to the present invention is printable with a sublimation ink and comprises a carrier substrate. Said carrier substrate comprises a material selected from the group consisting of paper, films, nonwovens, textiles and combinations thereof and at least one sublimation ink receiving layer formed over at least a part of one surface of the carrier substrate. If a polymeric film is used as carrier substrate, the material will be selected to withstand the elevated temperature of the transfer process. Suitable polymeric materials include e.g. polyethylene terephthalate, polypropylene, polycarbonate, or acrylonitrile butadiene styrene. The carrier substrate typically has a thickness being in the range of from about 10 to about 500 μm, preferably of from about 100 to 300 μm and more preferably of about 200 μm. As used herein, the term “over” as in “formed over” means that the sublimation ink receiving layer may be in direct contact with the carrier substrate or one or more additional layers, including, but not limited to, further sublimation ink receiving layers, barrier layers, such as metallized layers, and/or primer layers, may be present between the carrier substrate and the sublimation ink receiving layer comprising the functional active ingredient. A sublimation ink receiving layer usually forms an outer surface of the transfer medium of the present invention.

The sublimation ink receiving layer comprises at least one pigment and at least one binder as well as at least one functional active ingredient. Said functional active ingredient can be transferred from the sublimation ink receiving layer to the surface of an article combined with the transfer medium in such a way that the article faces the sublimation ink receiving layer of the transfer medium by means of heat. Herein the pigment(s) and binder(s) of the sublimation ink receiving layer are essentially retained over the carrier substrate. While the additional presence of a sublimation dye is not excluded in a sublimation ink receiving layer of the transfer material of the present invention, the functional active ingredient does not represent a sublimation dye having an absorbance maximum at a wavelength λmaxin the region of from 400 to 700 nm of the electromagnetic spectrum.

The transfer medium of the present invention comprises at least one functional active ingredient which is not a sublimation dye as described above but nevertheless can be transferred under similar conditions to the surface of an article, so as to enable a simple and precise application of one or more functional active ingredients for imparting the desired properties to both flat and contoured surfaces of articles comprising various materials. The use of the transfer medium of the present invention allows the functional active ingredients to be applied to the entire surface of an article or to selected parts of the surface of an article only, thus saving costs and enabling a precise application to desired areas. Furthermore, the transfer medium of the present invention enables both simultaneous and sequential transfer of more than one functional active ingredient and/or sublimation dye.

