Technical Field of the Invention

The present invention relates to a method of transferring an image onto an article and to an article comprising an image produced by said method.

Background to the Invention

Designs or decorative patterns are often applied to an article by hand using transfer paper. A digital image of the desired design or decorative pattern is first produced on a computer. The image is then printed onto transfer paper using dyesublimation inks. The transfer paper is then applied onto a coated article and the image is transferred onto the article using a heat press or oven. The dye- sublimation inks will fuse into the coated article, and once left to cool and the backing on the transfer paper removed, the design will be visible on the article. However, it is well-known that images applied in this way fade if exposed to sunlight.

It is also known to print a design or decorative pattern of ceramic toners onto waterslide transfer paper. Once printed, the image is cut out and placed in warm water which causes the backing paper to detach from the film comprising the printed image. The film comprising the printed image is then positioned on the article. The article comprising the image is wiped, allowed to dry and then fired in a kiln at 800°C or above which causes the ceramic toners to fuse into the article. However, such a method is expensive due to the costs involved in repeatedly having to heat the kiln to 800°C or above extended periods of time.

Engraved, laser and sandblasting machines are also well-established methods for providing a decorative finish to an article. However, the design or decorative pattern may not be 100% visible when the engraved or lasered area is wet which can impair the quality of the engraved or lasered design/decorative pattern.

In light of the above it is an object of embodiments of the invention to provide a method of transferring a printed image onto an article which ameliorates one or more of the disadvantages mentioned above. In particular, it is an object of one or more embodiments of the present invention to provide an article comprising a printed image which does not fade when exposed to light. It is also an object of embodiments of the present invention to provide a cost-effective method for producing an article comprising a printed image which does not fade.

Summary of the Invention

According to a first aspect of the invention there is provided a method of providing an image on an article, the method comprising:

— printing an image on an image transfer layer using a ceramic toner;

— applying the image transfer layer comprising the printed image on the article; and

— applying a surface coating on the article. wherein the article comprising the printed image is not subjected to a firing treatment,

It has been found that by applying a surface coating on the article, either before or after application of the image transfer layer comprising the printed image that a robust and durable image can be obtained on the article without having to fire the article. This serves to reduce production costs and enable articles comprising printed images to be produced in shorter timeframes relative to conventional methods which involve firing in kilns or furnaces to fuse the printed image to the article. Moreover, since the present method does not include a firing step, it is now possible to apply printed images on a variety of articles since the article no longer needs to be able to withstand the high temperatures within the kiln. It has also been found that the present method results in printed images on articles that exhibit good UV stability due to the use of ceramic toners and improved fade resistance relative to printed images on articles which have been fired. The method further allows the images to be produced using a full range of colours and with a variety of surface finishes. Unlike printed images which have been fired in a kiln or furnace at temperatures above 800°C, the ceramic toners have not fused together or with the article on which they have been applied, i.e., the ceramic toners are present in an unfused condition.

The ceramic toners may be in the form of a powder. This is in contrast to ceramic inks and paints which are liquids.

The image transfer layer may comprise a synthetic paper.

The image transfer layer may comprise a polymeric material. In particular, the image transfer layer may comprise polyester paper. Advantageously, polyester paper does not fade, tear or need laminating. The inventors also found that polyester paper printed with ceramic toners improves the fade resistivity of the printed image in use and that the durability of the printed image could also be improved by subjecting the printed image to heat and pressure. The use of polyester paper also means that articles comprising the printed images are very suitable for use outside and/or in environments where the article may come into contact with water such as in bathrooms and kitchens.

In some embodiments the image transfer layer may comprise wallpaper. The polyester paper may have a thickness between 50 and 355 microns. In some embodiments the thickness may be between 50 and 200 microns. For example, the polyester paper may have a thickness of 175 microns, 150 microns, 125 microns. 100 microns, 75 microns or 50 microns.

The image transfer layer may be provided with an adhesive. The adhesive may be covered by a release layer which can be peeled away to expose the underlying adhesive prior to applying the image transfer layer to the article. In this embodiment the ceramic toner is printed on the exposed surface of the image transfer layer. In another embodiment, the image may be printed on the image transfer layer and an adhesive may thereafter be applied to the non-printed side of the image transfer layer. In another embodiment the adhesive may be applied to the article rather than to the image transfer layer. However, it will be appreciated that in some embodiments the adhesive can be applied to both the image transfer layer and the article.

In some embodiments the method may comprise the step of providing a sheet of decal transfer paper, said sheet comprising a backing paper, a release layer and an image transfer layer, and printing the image on the image transfer layer. In the field of the invention decal paper is also commonly known as water slide paper.

The method may comprise the further steps of:

— immersing the decal transfer paper comprising the printed image in water to release the image transfer layer from the backing paper, and

— applying the image transfer layer comprising the printed image on the article.

In some embodiments the image transfer layer comprising the printed image is applied on the article and the surface coating is applied over the image transfer layer. When the surface coating is applied over the image transfer layer, the surface coating may comprise a lacquer. In particular, the surface coating may comprise a clear lacquer. The lacquer may be applied to the image transfer layer comprising the printed image prior to application of the image transfer layer to the article. The lacquer may be cured. The lacquer may be cured by exposing it to ultraviolet or infrared radiation. Alternatively, the image transfer layer comprising the printed image and lacquer may be placed in an oven and subjected to a heat treatment. The heat treatment may be up to 400°C which is far below the temperature at which ceramic toners are normally fired.

The lacquer may comprise a synthetic polymer. The synthetic polymer may comprise an organic polymer such as an acrylic. The lacquer may be provided as an aerosol. The lacquer may be applied by spraying.

The surface coating may comprise a wax. The wax may be applied over the lacquer to further protect the printed image. In particular, the wax may be applied over the clear lacquer. The wax may be applied over the clear lacquer prior to or after the image transfer layer comprising the printed image has been applied to the article. The application of the wax also has the benefit of improving the visual appearance of the article.

In one embodiment the wax may be applied over the image transfer layer comprising the printed image.

In some embodiments the method comprises the steps of providing a decal transfer paper comprising an image transfer layer and a backing layer, printing an image on the image transfer layer, applying a surface coating on the article, applying the decal transfer paper comprising the printed image on the surface coating before the surface coating is fully cured and applying a liquid over the article once the surface coating is fully cured to release the backing layer from the image transfer layer.

The above method may be carried out without the use of a heat press which enables articles with printed images to be produced at a lower cost relative to those that are produced using a heat press or those that are fired in a kiln. When the surface coating is not in a fully cured condition it is tacky to the touch. The liquid applied over the article and decal transfer paper may be water or any other liquid capable of releasing the backing paper. Pressure may be applied to the decal transfer paper as it is provided on the surface coating, e.g., by an operative pressing down on the decal transfer paper on the article.

In some embodiments, the image transfer layer may comprise sublimation paper. When the image transfer layer comprises sublimation paper, the surface coating may be applied on the article and the image transfer layer comprising the printed image may be applied over the surface coating.

The printed image may be transferred from the image transfer layer onto the underlying surface coating using a heat press.

In some embodiments a heat press can be used to transfer the image onto the article or an underlying surface coating by applying pressure at ambient temperature, i.e., without applying heat.

In some embodiments the printed image may be transferred from the image transfer layer onto the article or an underlying surface coating using a hydraulic press. In other embodiments, the printed image may be transferred from the image transfer layer onto the article or an underlying surface coating by bringing the image transfer layer into contact with the article or underlying surface coating and compressing them together. This may be achieved through the use of a suitable clamp, e.g., a G-clamp.

The printed image may be transferred from the image transfer layer to the underlying surface coating at temperatures up to 400°C. In some embodiments, the temperature of the heat press may be between 20°C and 230°C. If temperatures above 400°C are used, then the underlying surface coating peels and/or discolours.

In some embodiments the printed image may be transferred from the image transfer layer to the article or an underlying surface coating at a temperature below 300 °C. Suitably, the printed image may be transferred at a temperature below 250 °C. In some embodiments the printed image may be transferred at a temperature below 200 °C. In particular, the printed image may be transferred at a temperature below 150 °C. For example, the printed image may be transferred at 100 °C or less. Suitably, the image may be transferred at 60-80°C. Alternatively, the image may be transferred at ambient temperature.

The article may comprise metal, glass, ceramics, fabric, carpet, plastics such as PVC or polyester, wood, brick, concrete, slate or rock such as granite.

If the article comprises metal, glass or rock then the printed image may be transferred from the image transfer layer to the underlying surface coating at temperatures up to 230°C. In particular, it may be heated to a temperature between 20°C and 230°C.

If the article comprises a plastic, then the printed image may be transferred from the image transfer layer to the underlying surface coating at temperatures up to 120°C.

In particular, articles comprising PVC may be heated to a temperature between 50°C and 90°C. In embodiments where the article comprises polyester, e.g., polyester paper, it may be heated to a temperature between 20°C and 120°C.

If the article comprises wood, e.g., in the form of wooden blinds, the printed image may be transferred from the image transfer layer to the underlying surface coating at a temperature between 20 and 200°C.

If the article comprises a fabric, the printed image may be transferred from the image transfer layer to the underlying surface coating at a temperature between 20°C and 180°C. The heat press treatment may be for a period of 3 to 30 minutes, preferably 3 to 10 minutes. Accordingly, significantly less time is required to transfer the printed image to the article relative to conventional firing methods which involve heating articles in a kiln or furnace for around 24 hours.

The process of transferring the printed image from the image transfer layer to the article or underlying surface coating may be less than 120 minutes. In some embodiments the transfer process may be for 90 minutes or less or for 60 minutes or less. Suitably, the transfer process may be for a period of 3 to 30 minutes, preferably 3 to 10 minutes.

The surface coating in this embodiment may be clear, white or coloured. The surface coating may comprise a clear, white or coloured lacquer. In some embodiments a clear aerosol lacquer may be used. Such lacquers can be cured at 40-120°C. The lacquer may be applied by spraying. For example, the lacquer may be applied using an aerosol can or by using a spray gun.

A top-coat may be provided over the printed image on the clear, white or coloured surface coating. The top-coat may comprise a clear lacquer and/or wax. Prior to application of the clear, white or coloured surface coating, a predetermined area of the article may be subjected to an abrasion blasting treatment for improving adhesion of the surface coating to the article.

According to a second aspect of the invention there is provided an unfired article comprising a printed image containing a ceramic toner, wherein the article comprises a surface coating above and/or below the printed image. By unfired, it is meant that the article comprising the printed image has not been placed in a kiln or furnace and heated to a temperature of around 800°C or above. As such, ceramic toner particles in the printed image are in an un-fused condition.

Advantageously, robust and durable images can be obtained on the article without having to fire the article. Moreover, the printed images exhibit very good fade resistance.

In some embodiments the article may comprise an image transfer layer having a printed image containing ceramic toners and a surface coating provided over the image transfer layer.

The article according to the second aspect of the invention may include any or all features described in relation to the first aspect of the invention.

The image transfer layer may comprise polyester paper. Alternatively, the image transfer layer may be the image transfer layer from a decal transfer paper. In another embodiment the image transfer layer may comprise sublimation paper.

In some embodiments an adhesive may be present between the article and the image transfer layer comprising the printed image. The surface coating may comprise a lacquer and/or a wax. The lacquer may be a clear lacquer, e.g., in embodiments where the surface coating provided over the image transfer layer or printed image. The lacquer may be a polyester-based lacquer or an acrylic based lacquer.

In one embodiment an adhesive may be present on the article, the image transfer layer may be present on the adhesive, the printed image may be present on the image transfer layer and a surface coating, e.g. a clear lacquer, may be present on the printed image.

In another embodiment, an adhesive may be present on the article, the image transfer layer may be present on the adhesive, the printed image may be present on the image transfer layer, a surface coating, e.g. a clear lacquer, may be present on the printed image and a wax may be present on the lacquer.

In some embodiments an adhesive may be present on the article, the image transfer layer may be present on the adhesive, the printed image may be present the image transfer layer and a wax may be present on the printed image.

In a further embodiment a surface coating, e.g. a white or coloured lacquer, may be present on the article and the printed image containing ceramic toners may be present on the white or coloured lacquer. A top-coat such as a clear lacquer may be provided on the printed image and a wax may optionally be provided on the clear lacquer.

The article may comprise metal, glass, ceramics, fabric, carpet, plastics such as PVC or polyester, wood, brick, concrete, slate or rock such as granite.

According to a third aspect of the invention there is provided an image transfer layer comprising a printed image containing a ceramic toner and a surface coating provided over the printed image. The image transfer layer according to the third aspect of the invention may include any or all of the features described in relation to the first and second aspects of the invention.

The image transfer layer may comprise polyester paper or is an image transfer layer from decal transfer paper. The surface coating may comprise a lacquer and/or a wax. The lacquer may be a clear lacquer.

According to a fourth aspect of the invention there is provided a kit comprising an image transfer layer, a ceramic toner for printing onto the image transfer layer and a surface coating composition.

The kit according to fourth aspect of the invention may include any or all of the features described in relation to the first, second and third aspects of the invention.

The surface coating composition may comprise a lacquer and/or a wax. In particular, the surface coating may comprise a clear lacquer for application over the printed image or a white or coloured lacquer for direct application onto the article.

The kit may further comprise one or more of the following items: a composition for cleaning the article, an adhesive, a filler and tools.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figure 1 shows a cross-sectional view of an unfired article comprising a printed image. Figure 2 shows another cross-sectional view of an unfired article comprising a printed image.

As best shown in Figure 1 there is provided an unfired ceramic article 100 such as a tile comprising a printed image 10. An adhesive layer 20 is present between the ceramic article 30 and an image transfer layer for adhering the image transfer layer 40 to the article 30. The image transfer layer 40 comprises a printed image 10 containing one or more ceramic toners. Finally, a surface coating 50 comprising a lacquer (Hycote Clear Lacquer B053343) is provided over the image transfer layer 40 comprising the printed image 10 to protect the printed image 10.

In one embodiment the unfired article shown in Figure 1 is produced by first providing an image transfer layer formed of polyester paper 40 (Kernow polyester dry toner HWT paper). The image transfer layer 40 comprises an adhesive 20 on one side which is covered by a release layer (not shown). A user then selects an image for printing onto the image transfer layer 40. The image may be a photograph, a decorative image such as a pattern or picture, letters or words. If desired, the image may be manipulated using suitable image manipulation software on a computer. The image transfer layer 40 is then placed in a digital printer, e.g., a KIP 660 or Ricoh SPC83O printer, and the selected image is printed using one or more ceramic toners. The ceramic toners include, but are not limited to magenta, cyan, yellow, black and red ceramic toners (Baltea D.C). If appropriate, the image transfer layer 40 comprising the printed image 10 may be cut to a desired size. A surface coating 50 comprising a lacquer 50 is then applied over the printed image by spraying, rolling, hand painting, or screen printing. The image transfer layer 40 is then exposed to ultraviolet or infrared radiation for a period of 30 minutes in order to cure the surface coating 50. The cured surface coating 50 protects the image and depending on the lacquer used provides a gloss, matt, or satin finish. As best shown in Figure 2, a further surface coating 60 in the form of a wax may be provided over the cured surface coating 50 to provide additional protection to the underlying printed image 10 and image transfer layer 40. To apply the image transfer layer 40 to the ceramic article 30, a user peels away the release layer to expose the underlying adhesive 20. The adhesive 20 is then brought into contact with the ceramic article 30 to secure the image transfer layer 40 comprising the printed image 10 to the article 30. The article 30 comprising the printed image 10 is not fired.

In another embodiment a user prints the selected image on an image transfer layer 40 present on decal transfer paper. The decal transfer paper comprises a backing paper, a release layer on the backing paper and an image transfer layer 40 on the release layer. A surface coating 50 in the form of a lacquer is then applied over the printed image 10 and exposed regions of the image transfer layer 40, i.e. those parts not covered by the printed image. The decal transfer paper is then immersed in water which causes the backing paper to detach and float away from the image transfer layer 40 comprising the printed image 10 and surface coating 50. The image transfer layer 40 is then applied on the article, wiped and/or rolled and allowed to dry. The article 30 comprising the printed image 10 is not fired.

In a further embodiment a pre-determined area of an article, e.g. granite, is subjected to an abrasive blasting treatment such as sand blasting. A layer of white lacquer is then applied on the blasted area, e.g. by spraying, and the white lacquer (Tetrosyl ATS011 white primer, Axalta) is subsequently cured using ultraviolet or infrared radiation for a period of 30 minutes. An image containing ceramic toners is printed onto sublimation paper (image transfer layer) and the sublimation paper (S- Race (RTM)) comprising the printed image is then applied on top of the cured white lacquer. The printed image is then transferred onto the white lacquer using a heat press at a temperature between 150°C and 200°C for 3 to 8 minutes. A surface coating 50 comprising a lacquer (Hycote Clear Lacquer B053343) is then provided over the printed image 10 and cured to protect the printed image 10.

In another embodiment a colourless gloss base coat such as COLOURLESSGLOSS W31-GL041 (Axalta) may be applied to an article instead of the white lacquer. In such embodiments the colourless gloss base coat is cured between 160°C and 200°C for 5-25 minutes. An image containing ceramic toners is printed onto sublimation paper (image transfer layer) and the sublimation paper (S-Race (RTM)) comprising the printed image is then applied on top of the cured white lacquer. The printed image is then transferred onto the white lacquer using a heat press at a temperature between 150°C and 200°C for 3 to 8 minutes. A surface coating 50 comprising a lacquer (Hycote Clear Lacquer B053343) is then provided over the printed image 10 and cured to protect the printed image 10.

The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.