System for generating a permanent image and use of an application preparation for generating a permanent image

Abstract

System for generating a permanent image including: - one image template: - a first layer that has at least one motif and - a second hydrochromic layer arranged on top of the first layer - an application preparation, wherein the application preparation: - at least one first transparent liquid with a boiling point of more than 150 °C at an atmospheric pressure of 1000 hPa and - includes at least one second transparent liquid that is volatile at 25 °C and an air pressure of 1000 hPa.

Description

[0001] The present invention relates to a system for generating a permanent image and the use of a specific application preparation for generating a permanent image.

[0002] For many years, so-called water-based coloring books for children have been available on the market. A water-based coloring book is a coloring book in which images are created by applying water. The images created with water are initially invisible on the unused pages of the coloring book, as they are covered by an opaque, usually white, matte hydrochromic layer. This layer becomes transparent upon contact with water, revealing the image underneath. The effect used in these coloring books is also known as the "wet reveal" effect, and hydrochromic inks can be obtained, for example, from the company "Coates."

[0003] A disadvantage of commercially available systems with hydrochromic layers, such as the aforementioned coloring books, is that the effect of revealing the image or motif beneath the hydrochromic layer is temporary and only lasts until the applied water evaporates. While this allows the coloring book to be reused, it does not permanently create the underlying image.

[0004] Furthermore, it was found that when a high-boiling-point liquid is used instead of water to make the image or motif visible, an oily film forms on the surface of the now transparent hydrochromic layer if over-applied. This film remains there, which can lead to soiling of the object or body part that comes into contact with the image during transport, storage, or even just touching the hydrochromic layer, and also to soiling of the image itself. In addition, high-boiling-point liquids are usually characterized by a high viscosity compared to water, making it difficult to spread the high-boiling-point liquid evenly in a thin layer on the hydrochromic layer.

[0005] Based on this prior art, it is an object of the present invention to provide a system for producing a permanent image in which an oil film formed by over-application is avoided and a uniformly thin application is enabled. Furthermore, it is an object of the present invention to provide the use of an application preparation.

[0006] The problems are solved by the features of the independent claims. The dependent claims contain advantageous further developments and embodiments of the invention.

[0007] According to a first aspect of the present invention, the problem is solved by a system comprising an image template and an application preparation. The image template comprises a first layer and a second layer and may include further layers. The first layer is the layer that produces the final image. It comprises at least one motif, which can be designed in any form, color, size, and detail. Two or more motifs can also be combined and contained in the first layer.

[0008] The second layer, a second hydrochromic layer, is applied to the first. This second layer can partially or even completely cover the first. It acts as a matting layer, being opaque and thus whitish in color, and therefore covering the motif(s) of the first underlying layer, rendering them invisible.

[0009] For the purposes of the present invention, a hydrochromic layer is understood to be a layer that changes its appearance from opaque to transparent upon contact with water. The second hydrochromic layer is formed, in particular, from a hydrochromic ink that is applied to the first layer or a transparent intermediate layer and then dried. Hydrochromic inks are commercially available, for example, under the trade name PF 70 / 32 from Coates. The second hydrochromic layer may also include motifs, but this is not mandatory. To encourage the application of the applicator preparation, motifs are preferably also present in the second hydrochromic layer, designed to promote the application of the applicator preparation in specific areas of the second hydrochromic layer.

[0010] Unlike conventional watercolor books that use water, the system according to the invention comprises an application preparation. This preparation includes at least one first transparent liquid with a boiling point of at least 150 °C at an atmospheric pressure of 1000 hPa and at least one second transparent liquid that is volatile at 25 °C and an atmospheric pressure of 1000 hPa. The higher the boiling point of the first transparent liquid, the more permanent the resulting image.

[0011] The term "first transparent liquid" as used in the present invention refers not only to a liquid with a boiling point of at least 150 °C at an atmospheric pressure of 1000 hPa, but also to a liquid with sufficiently high transparency. Specifically, the first transparent liquid has a transmission of 0.02% to less than 100%. Transmission is defined as the ratio of outgoing light intensity to incident light intensity and is measured photometrically using light with a wavelength between 400 and 800 nm, for example, at 550 nm. The higher the transmission, the greater the transparency of the liquid and the more clearly the motif of the first layer appears beneath the then transparent second layer.

[0012] The second transparent liquid within the meaning of the present invention is understood to be any liquid or mixture of such liquids that is volatile at 25 °C and an atmospheric pressure of 1000 hPa. The second transparent liquid also has a sufficiently high transparency, in particular a transmission of 0.02% to less than 100%, as measured above for the first transparent liquid.

[0013] The volatility of the second transparent liquid is crucial and essentially distinguishes it from the first. The second transparent liquid used according to the invention is therefore understood to be a liquid with an evaporation rate, measured according to DIN 53170, in the range of 5 to 90. The evaporation rate is defined here as the time a liquid requires to evaporate relative to diethyl ether. The second transparent liquid does not enable the creation of a permanent image, but it is essential for the uniform application of the application preparation in a relatively thin layer and also for diluting the first transparent liquid, which is a high-boiling liquid, to such an extent that even in case of over-application, no oily, greasy, or rancid film remains on the surface of the resulting transparent hydrochromic layer.The second transparent liquid dilutes the first transparent liquid, so that together both transparent liquids produce a very good homogeneous application and a permanently clearly visible image / motif.

[0014] When the application preparation described above is applied to the surface of the second hydrochromic layer, the hydrochromic layer becomes transparent, thus losing its opacity or inherent color and therefore its matting effect, allowing the motif(s) of the first layer beneath the hydrochromic layer to show through. Because the first transparent liquid has a boiling point of at least 150 °C, only the second transparent liquid evaporates, while the first transparent liquid remains on or within the surface of the second hydrochromic layer, creating the transparency of the hydrochromic layer, which is permanently maintained and thus keeps the motif(s) of the first layer permanently visible.

[0015] The boiling point of the first transparent liquid is not limited in detail and can be arbitrarily high, as long as it is at least 150 °C, measured at an atmospheric pressure of 1000 hPa.

[0016] The first and second transparent liquids are otherwise not subject to any further restrictions. However, the transparent liquids should not contain any substances that would dissolve or degrade the image motif in the first layer, as otherwise the image motif would "bleed" upon contact with the application preparation and thus be less visible.

[0017] The system according to the invention is characterized by a simple and efficient composition, by which a pre-made image comprising at least one motif contained in the first layer can be made permanently visible by homogeneous thin-layer application of the application preparation without leaving an oily surface film.

[0018] According to a particularly advantageous refinement, the application preparation is a single-phase preparation. Single-phase nature refers to a state in which the application preparation exists at 25 °C and an atmospheric pressure of 1000 hPa. No phase separation is visually discernible. This has the advantage that the application preparation can be produced using the simplest technical means and is not subject to decomposition or separation even during storage, resulting in a very long shelf life for the system.

[0019] Preferably, the first transparent liquid comprises a silicone oil and / or an ester oil. Silicone oils are characterized by high stability, particularly with respect to oxygen, thus ensuring the long shelf life of the system according to the invention. Ester oils also exhibit a relatively low tendency to oxidize and have the advantage over silicone oils of often being derived from renewable raw materials, thereby improving the sustainability of the system. Both types of oil are also characterized by high transparency and good spreading properties on various surfaces, further improving the spreadability of the application preparation.

[0020] Due to its high refractive index and thus very high transparency, silicone oil is primarily a polysiloxane, advantageously selected from polydimethylsiloxanes, phenyl-substituted polysiloxanes, polyether-modified polysiloxanes, and mixtures thereof. The transparency is particularly high in phenyl-substituted polysiloxanes, such as phenyl trimethicone, phenyldimethicone, and the like. Polyether-modified polysiloxanes are characterized by improved miscibility with other, more polar oils, i.e., ester oils, so mixtures of polyether-modified polysiloxanes are especially advantageous when used in combination with ester oils.Unsubstituted and unmodified polydimethylsiloxanes can be obtained in different viscosities, so their use is advantageous when the viscosity is not only to be adjusted via the second transparent liquid, but the viscosity is to be shifted from the outset into a range that is advantageous for a specific application device for applying the application preparation.

[0021] Due to its sustainability and environmental friendliness, the ester oil is particularly preferred from isopropyl myristate, isopropyl palmitate, jojoa oil, glyceryl esters and mixtures thereof.

[0022] To form a system that is stable even at higher temperatures, such as those encountered during storage or transport of the system according to the invention, the second transparent liquid is advantageously an alcohol or a mixture of alcohols. Alcohols are partially miscible with, in particular, low-viscosity silicone oils, such as dimethylsiloxane, which is miscible with isopropanol in any proportion, and also with ester oils. Furthermore, they have the advantage of preventing microbial contamination, so that the system is also characterized by a consistently high shelf life, even after the application preparation has been opened.

[0023] For the reasons stated above, the alcohol is preferably selected from ethanol and isopropanol. Any mixture of ethanol and isopropanol can also be used as the second transparent liquid.

[0024] According to an alternative advantageous embodiment of the system, the first transparent liquid comprises glycerin and / or at least one glycol and / or a glycol ether and / or a glycol ester. Glycerin, glycols, glycol ethers, and glycol esters are cost-effective compounds available in various viscosities, typically temperature- and oxygen-resistant, with high boiling points, and can be selected according to the choice of glycol chain length. Particularly preferred, due to the advantages mentioned above, are ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, polyethylene glycol, polypropylene glycol, and poly(ethylene / propylene) glycol, each including all possible isomers.

[0025] Due to its very good evaporation rate, the second transparent liquid is preferably selected from ethanol, isopropanol, water, and mixtures thereof. In particular, combinations of glycerin and / or at least one glycol and / or a glycol ether and / or a glycol ester as the first transparent liquid with water and / or especially ethanol, isopropanol, or a mixture of ethanol and isopropanol have proven to be advantageous, since these substances are homogeneously miscible with each other over a very wide range, and the alcohol content also helps to prevent microbial contamination of the application preparation.

[0026] To achieve consistently good image quality, it is advantageous for the proportion of the first transparent liquid in the application preparation to be between 30 and 80% by mass, and especially between 40 and 70% by mass. The higher the proportion of the first transparent liquid relative to the total mass of the application preparation, the sharper and more permanently visible the image resulting from the first layer. However, the greater the risk of an oil film remaining on the surface of the second hydrochromic layer if the application preparation is overapplied. Furthermore, the application may not be uniform and thin due to the high viscosity of the first transparent liquid, which in turn encourages overapplication by the user because the image is not initially produced with consistent quality in all areas.However, if the proportion of the first transparent liquid is low, i.e., less than 40% by mass and especially less than 30% by mass of the total mass of the application preparation, the image cannot be made permanently visible with sufficient quality. It has therefore been found that the permanent image is produced particularly well when the proportion of the first transparent liquid in the application preparation is between 30% and 80% by mass and especially between 40% and 70% by mass. If two or more first transparent liquids are used in the application preparation, the quantities specified here refer to the total quantity of all first transparent liquids.

[0027] A further advantageous development stipulates that the proportion of the second transparent liquid in the application preparation, relative to the total mass of the application preparation, should be between 20 and 70% by mass, and particularly between 30 and 60% by mass. The higher the proportion of the second transparent liquid, the better the spreading, i.e., the spreadability of the application preparation on the hydrochromic layer due to the reduction in viscosity of the application preparation, and the lower the risk of over-application and thus the formation of an oily surface layer. However, the higher the proportion of the second transparent liquid in the application preparation, the lower the consistently good quality of the resulting image.A very good compromise between homogeneous, uniformly thin application of the solution onto the hydrochromic layer and very good persistence of a high-quality image is achieved when the proportion of the second transparent liquid, based on the total mass of the solution, is 20 to 70% by mass, and particularly 30 to 60% by mass. If two or more second transparent liquids are used in the solution, the quantities specified here refer to the total quantity of all second transparent liquids.

[0028] For the reasons stated above, it is further preferred if the mass ratio of the first transparent liquid to the second transparent liquid in the application preparation is 4 : 1 to 1 : 2.33.

[0029] According to a further alternative advantageous embodiment, the application preparation is an emulsion. For the purposes of the present invention, an emulsion is understood to be a homogeneous dispersion consisting of at least two phases, in which one phase, the so-called inner phase, is dispersed droplets within a continuous outer phase, wherein both the inner and outer phases are liquid phases. Oil-in-water (O / W) emulsions are commonly used, in which an oil phase forms the inner phase and an aqueous phase or water phase forms the outer phase. Water-in-oil (W / O) emulsions also exist, in which an aqueous phase or water phase forms the inner phase and an oil phase forms the outer phase. Furthermore, there are also multiple emulsions with three or more phases, such as a water-in-water (W / O / W) emulsion or an oil-in-water (O / W / O) emulsion. It is understood that the term "oil phase" also includes a phase that may comprise silicone oils and the like.

[0030] An emulsion as a form of application preparation has therefore proven advantageous because it offers a stable application form between lipophilic and / or silicone oil-based substances, such as polysiloxanes in particular, and hydrophilic, aqueous and / or aqueous-alcoholic substances, which does not settle, can be stored well and therefore enables long-term use.

[0031] Due to its very good spreadability and lower viscosity, the emulsion is preferably an O / W emulsion, wherein "oil", as already explained above, also includes silicone oil or mixtures of different oils and silicone oils, all of which, however, meet the requirement of a boiling point of more than 150 °C at 1000 hPa atmospheric pressure.

[0032] For reasons of high transparency and good emulsifying properties, the first transparent liquid preferably comprises at least one vegetable oil, one synthetic oil, one petroleum-based oil, one alcohol, one silicone oil, in particular one polysiloxane, or any mixture thereof. It is understood that all substances mentioned herein must also meet the requirement of a boiling point of more than 150 °C at 1000 hPa.

[0033] Among the aforementioned types of oil, sunflower oil, rapeseed oil, linseed oil, walnut oil, olive oil, ester oils such as in particular isopropyl myristate, isopropyl palmitate and jojoba oil, paraffin oils, polydimethylsiloxanes, phenyl-substituted polysiloxanes, polyether-modified silicone oils, aminoalkyl-substituted polysiloxanes and any mixtures thereof are preferably preferred as the first transparent liquid.

[0034] To improve the spreading of the application preparation and to produce a permanent image as quickly as possible after its application, the second transparent liquid is preferably selected from ethanol, isopropanol, water and mixtures thereof, and is in particular water.

[0035] To stabilize the emulsion, particularly during storage or application at higher temperatures, the application preparation advantageously comprises at least one emulsifier, wherein the emulsifier has a hydrostatic head (HLB) of at least 9. This particularly promotes the formation of an oil-in-water (O / W) emulsion. Depending on the type, the emulsifier can be used in appropriate proportions, which can be determined through routine testing.

[0036] To form a particularly stable emulsion that does not settle or separate, it is advantageous if the proportion of the first transparent liquid in the application preparation is 5 to 50% by mass, and especially 10 to 40% by mass. If two or more first transparent liquids are used in the application preparation, the quantities specified here refer to the total quantity of all first transparent liquids.

[0037] To improve the spreadability of the application preparation while maintaining high emulsion stability and simultaneously preventing the formation of an oily film due to over-application, the proportion of the second transparent liquid in the application preparation is preferably 50 to 95% by mass and particularly 60 to 90% by mass. If two or more second transparent liquids are used in the application preparation, the quantities specified here refer to the total quantity of all second transparent liquids.

[0038] For the reasons stated above, it is further preferred if the mass ratio of the first transparent liquid to the second transparent liquid is 1 : 1 to 1 : 19.

[0039] In order to promote the spreadability of the application preparation and thus to be able to apply a uniformly thin but sufficiently large quantity of application preparation to the hydrochromic layer, the application preparation advantageously has a dynamic viscosity, measured at 25 °C using a Brookfield DV-1 rotational viscometer, in a range of 2 mPa·s to 40 mPa·s and in particular in a range of 3 mPa·s to 35 mPa·s.

[0040] To create a permanently and highly visible image, the first layer advantageously comprises a plastic-based, a fiber-based, or a textile-based medium. Plastic-based media are understood to be those media that exist in the form of a layer or film of varying thickness. These can include, for example, packaging films, but also clothing and parts thereof. Fiber-based media are understood to be media that comprise fibers of any kind. The fibers can be synthetic, natural, or nature-identical. Particularly common fiber-based media are fleece, paper, and cardboard, with paper and cardboard primarily containing cellulose fibers. Textile media are understood to be woven, braided, knitted, or crocheted media, which are used especially for clothing, furniture, and home accessories.The materials used for this purpose are not limited in detail and can also be synthetic, natural or nature-identical.

[0041] The motif(s) of the first layer can preferably be applied to the plastic-based, fiber-based, or textile-based medium described above. Printing processes, such as offset printing, are particularly suitable for this purpose. Printing processes produce the motifs with exceptional accuracy and long-lasting stability.

[0042] As already explained above, the design of the motif(s) of the first layer is essentially unrestricted. Preferably, the motif(s) is formed in one or more colors. This makes the motif stand out particularly well from the medium of the first layer and also from the second layer, which is formed in particular with white or opaque color.

[0043] According to a further advantageous embodiment, the second hydrochromic layer is formed from a dried hydrochromic ink applied to the first layer. In other words, a hydrochromic ink known in the art and available on the market can be used to produce the second hydrochromic layer, which forms the second hydrochromic layer after any solvents have dried. "Drying" here refers not only to the evaporation of solvents but also to curing, such as curing with UV radiation. Any method of fixing the second hydrochromic layer to the first layer is suitable.

[0044] Preferably, a hydrochromic ink usable for the present invention for forming the second hydrochromic layer comprises at least one solvent, at least one binder, and at least one pigment, wherein the binder may be selected from acrylic resins, alkyd resins, polyurethane resins, and polyester resins, and wherein the pigment is selected from sodium aluminum silicates, amorphous silicas, clay, gypsum, aluminum oxides, talc (magnesium silicate), and metal carbonates. Preferably, no further pigments are included to improve transparency upon contact with the application preparation. The particle sizes of the pigments are preferably in the range of 1 to 35 µm. The particle size is defined as the D50 value, which is measured in suspension by means of dynamic light scattering.

[0045] A hydrochromic layer applied using a screen printing process is particularly advantageous, as screen printing allows for precise adjustment of the hydrochromic layer thickness.

[0046] In order to expose the motif(s) of the first layer for a particularly long time and thus permanently through the transparency of the second layer, the first transparent liquid preferably has a vapor pressure of less than 1000 hPa at 20 °C.

[0047] To improve the distribution of the application preparation on the second hydrochromic layer, the system according to the invention can further include an application device. To improve the spreadability of the application preparation, it is preferably provided in a writing or painting device. The writing or painting device can thus be part of the system. For this purpose, the writing or painting device particularly includes a reservoir containing the application preparation, from which the application preparation can be dispensed for application. The reservoir can simply be a storage container in which the application preparation is present in its unbound state, or it can also be a fiber storage device.Suitable application devices therefore include markers with fiber storage and tip, "free ink" markers with free application preparation in a tank and a valve system for dispensing, or markers with free application preparation in a tank with an associated pressure and heat compensation component. Alternatively, the application preparation can also be applied using brushes, rollers, cloths, sponges, or similar tools.

[0048] To effectively prevent the application preparation from flowing or spreading and thus promote the permanence of the generated image, the image template preferably comprises a barrier layer beneath the first layer or between the first layer and the second hydrochromic layer. For the purposes of the present invention, a barrier layer is understood to be a layer characterized by low porosity and low absorption capacity for the application preparation, such that the application preparation is not absorbed by the barrier layer and its polarity is, in particular, opposite to that of the application preparation.

[0049] The barrier layer can consist of a transparent material, such as polypropylene, PVC, polyester, and the like. The barrier layer prevents the application preparation, and in particular the initial transparent liquid it contains, from being absorbed away from the substrate of the image, as this could impair the image's permanence. The barrier layer does not necessarily have to be in the form of a film. It is also conceivable to place a barrier layer above or below the image using printing techniques.

[0050] Advantageously, according to one embodiment, the system according to the invention also includes a transparent film arranged between the first layer and the second hydrochromic layer. The transparent film can be the aforementioned barrier layer, but it can also be an alternative or additional transparent film. The use of a transparent film has the advantage that the hydrochromic layer can be applied directly to the film and thus produced in a separate step. Furthermore, the use of the transparent film in the production of the image template protects the motif of the first layer. Sufficiently high transparency of the film is achieved, in particular, when it has a transmission of 0.02% to less than 100%.Transmission is the ratio of outgoing light intensity to incident light intensity and is measured photometrically using light with a wavelength between 400 and 800 nm, for example, at 550 nm. The higher the transmission, the greater the transparency of the film and the more clearly the image of the first layer appears beneath the transparent second layer.

[0051] The specific material of the transparent film is not limited. Due to their durability and mechanical stability, plastic-based films have proven particularly advantageous. Among these, films containing polyolefins, and especially polypropylene or polypropylene copolymers such as propylene / ethylene copolymer, are particularly preferred. This is due, in part, to their permanent transparency and low tendency to yellow, which allows the design to stand out particularly well.

[0052] The transparent film can adhere due to electrostatic interactions between the first layer and the hydrochromic layer.

[0053] However, it is also advantageous if an adhesive layer is present between the transparent film and the first layer, or if the transparent film is self-adhesive on a surface facing the first layer. This allows for a more stable bond between the first motif layer and the second hydrochromic layer.

[0054] If an adhesive layer is present, it preferably comprises an acrylate-based adhesive, a pressure-sensitive adhesive, a hot-melt adhesive, or a light-cured adhesive. These adhesives are characterized by high user-friendliness, ease of use, and good adhesive properties, and are therefore preferred.

[0055] A method for producing a permanent image is also described, but is not part of the present invention. The method comprises a step of forming an image template with at least two layers, comprising a first layer having at least one motif and a second hydrochromic layer arranged on the first layer. Particularly suitable adhesives are PUR adhesives, polyolefin copolymers, and polyvinyl acetate adhesives, such as those marketed, for example, under the trade name "Vinnapas" by Wacker AG.

[0056] The second hydrochromic layer can be created using a hydrochromic ink. Alternatively, the hydrochromic layer can be applied to a transparent film, which then acts like the barrier layer or transfer film described above for the hydrochromic layer. A second hydrochromic layer formed in this way can then be bonded to the first layer, for example, by an adhesive or bonding agent.

[0057] Then, an application preparation as described above, comprising at least a first transparent liquid with a boiling point of more than 150 °C at 1000 hPa atmospheric pressure and at least a second transparent liquid volatile at 25 °C and an atmospheric pressure of 1000 hPa, is applied to the second hydrochromic layer.

[0058] In the areas where the application preparation is applied to the second layer, the opacity of the second layer changes to transparent, so that the motif(s) of the first layer lying under the second layer and covered by the second layer become visible in these areas due to the transparency of the second layer.

[0059] The process is easy to apply without high technical effort and enables the creative creation of a permanent image that is initially invisible, whereby the process, through the use of the application preparation, prevents the formation of an oil film on the surface of the second hydrochromic layer due to over-application and applies an evenly thin layer of the application preparation, resulting in a high quality of the permanently generated image.

[0060] With regard to the advantageous embodiments of the method, further reference is made to the system according to the invention.

[0061] Another aspect of the invention relates to the use of an application preparation as described above. The application of the application preparation is carried out with the aim of producing a high-quality permanent image from an image template comprising a first layer having at least one motif and a second hydrochromic layer arranged on the first layer, while avoiding the formation of an oil film on the second hydrochromic layer by over-application of the application preparation. The image can be produced by the method disclosed above and thus by applying the application preparation.

[0062] The advantages, beneficial effects and further developments described for the system and use according to the invention are mutually applicable. - Examples - Example 1

[0063] Below, a recipe is given for components for forming a first layer according to the invention and for components for forming a second layer according to the invention. First shift:

[0064] The first layer (bearing the motif) is a cardboard surface (white) printed with corresponding motifs using the following ingredients: - 10% by mass of color pigment (e.g. HelioBeit LW 305, HelioBeit-LW 905 from Helio Beit or others) - 30% by weight polymer dispersion Esacote AC 200 (from Lamberti surface treatment) - 0.3% by mass defoamer BYK-019 (from BYK) - 2% by mass wetting agent DisperBYK-168 (from BYK) - 0-4 mass% RheoBYK-425 (for adjusting rheological properties; from BYK) - Rest: Water Second layer: - 50 wt% Bayhydrol UV 2720 / 1 (from Covestro AG); aqueous UV lacquer - 15% by mass Dorkafill H (kaolin; from Dorfner) - 15% by mass MinTalc 97-05 (talc; from Nobelmin) - 3% by mass Irgacure 500 (photoinitiator; from BASF) - 3% by mass Byk 348 (wetting agent; from BYK) - 0-3 mass% rheology additive to adjust the appropriate viscosity (so) - Rest: Water

[0065] The components of the second layer can optionally be mixed with polyisocyanate (e.g. Bayhydur 305) in a ratio of 10:1 (based on mass%) to obtain a 2-component system with increased abrasion resistance. Example 2

[0066] Furthermore, the following application preparations 1 to 3, as well as a comparison application preparation, were produced. These were single-phase application preparations with varying proportions of polyethylene glycol 200 as the first transparent liquid and water as the second transparent liquid. The dynamic viscosity of the application preparations was measured, and the application properties were determined. Viscosity was measured at room temperature using a Brookfield DV-1 rotational viscometer.

[0067] The results are summarized in the table below: Comparative application preparation Application preparation 1 Application preparation 2 Application preparation 3 Water - 20% by mass 40% by mass 60% by mass Polyethylene glycol 200 100% by mass 80% by mass 60% by mass 40% by mass Dynamic 45 m·Pas 22 mPa·s 9 mPa·s 4 mPa·s Viscosity 26 °C application Oily after drying / uneven application Slightly oily after drying / applying evenly Not oily after drying / applied evenly Non-oily / Even application / Design becomes less intense after drying

[0068] Among the application preparations 1 to 3, application preparation 2 was preferred due to the low viscosity and minimal stickiness of the hydrochromic layer after the water evaporated. Furthermore, due to its low viscosity, application preparation 2 was also very well suited for a fiber-tip applicator.

[0069] Application preparations 1 to 3, as well as the comparison application preparation, were each applied to an image template comprising a first motif-containing layer and a second hydrochromic layer (for example, as produced in Example 1), specifically to the hydrochromic layer. In all cases, the motif of the first layer became visible after the hydrochromic layer had changed from opaque to transparent through the application of the application preparation.

[0070] Due to overapplication caused by uneven application, a light oil film eventually floated on the hydrochromic layer onto which the comparison application preparation had been applied.

[0071] No oil film was visible on any of the other hydrochromic layers onto which the application preparations according to the invention had been applied. However, the image produced by applying application preparation 3 was somewhat less intense than the other images obtained by applying application preparations 1 and 2. Example 3

[0072] In addition, an emulsion-based application preparation was produced from the following raw materials: raw material function Quantity in mass % Oxypon 2145 (shimmer & black) Emulsifier; HLB: 11 5,0 Thin, liquid paraffin oil First transparent liquid 13,0 Novasol DS / 4 (sorbic acid) preservatives 0,3 Water demineralisiert Second transparent liquid 81,7 sum 100% by mass

[0073] A mixture of these raw materials was homogenized for 2 minutes at the highest setting of an Ultraturrax, resulting in a white, opaque emulsion of paraffin oil in water (O / W emulsion).

[0074] This application preparation, in the form of an emulsion, also exhibited the permanent wet reveal effect when applied to an image template as used in Example 2. The mixture was also well-suited for application with a brush, as the proportion of initial transparent liquid was low, allowing a large portion of the application preparation to evaporate.

Claims

[1] System for generating a permanent image comprising: - one image template: - a first layer that has at least one motif and - a second hydrochromic layer arranged on top of the first layer - an application preparation, wherein the application preparation: - at least one first transparent liquid with a boiling point of more than 150 °C at an atmospheric pressure of 1000 hPa and - includes at least one second transparent liquid that is volatile at 25 °C and an air pressure of 1000 hPa. [2] System according to claim 1, wherein the application preparation is a single-phase preparation. [3] System according to claim 2, wherein the first transparent liquid comprises a silicone oil and / or an ester oil. [4] System according to claim 3, wherein the silicone oil is selected from polysiloxanes, in particular from polydimethylsiloxanes, phenyl-substituted polysiloxanes, polyether-modified polysiloxanes and mixtures thereof. [5] System according to claim 3 or 4, wherein the ester oil is selected from isopropyl myristate, isopropyl palmitate, jojoa oil and glyceryl esters. [6] System according to any one of claims 2 to 5, wherein the second transparent liquid is an alcohol or a mixture of alcohols. [7] System according to claim 6, wherein the alcohol is selected from ethanol and isopropanol. [8] System according to claim 2, wherein the first transparent liquid comprises glycerin and / or at least one glycol and / or one glycol ether and / or one glycol ester, in particular selected from ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, polyethylene glycol, polypropylene glycol and poly(ethylene / propylene) glycol. [9] System according to claim 8, wherein the second transparent liquid is selected from ethanol, isopropanol, water and mixtures thereof. [10] System according to one of the preceding claims, wherein a proportion of the first transparent liquid in the application preparation is 30 to 80% by mass and in particular 40 to 70% by mass. [11] System according to one of the preceding claims, wherein a proportion of the second transparent liquid in the application preparation is 20 to 70% by mass and in particular 30 to 60% by mass. [12] System according to one of the preceding claims, wherein the mass ratio of the first transparent liquid to the second transparent liquid is 4 : 1 to 1 : 2.

33. [13] System according to claim 1, wherein the application preparation is an emulsion. [14] System according to claim 13, wherein the emulsion is an O / W emulsion. [15] System according to claim 13 or 14, wherein the first transparent liquid comprises at least a vegetable oil, a synthetic oil, a petroleum-based oil, an alcohol, a silicone oil, in particular a polysiloxane or any mixture thereof. [16] System according to claim 15, wherein the first transparent liquid is selected from sunflower oil, rapeseed oil, linseed oil, walnut oil, olive oil, ester oils, such as in particular isopropyl myristate, isopropyl palmitate and jojoba oil, paraffin oils, polydimethylsiloxane, phenyl-substituted polysiloxanes, polyether-modified silicone oils, aminoalkyl-substituted polysiloxanes and any mixtures thereof. [17] System according to any one of claims 13 to 16, wherein the second transparent liquid is selected from ethanol, isopropanol, water and mixtures thereof and in particular is water. [18] System according to any one of claims 13 to 17, wherein the application preparation comprises at least one emulsifier, wherein the emulsifier in particular has an HLB value of at least 9. [19] System according to any one of claims 13 to 18, wherein the proportion of the first transparent liquid in the application preparation is 5 to 50% by mass and in particular 10 to 40% by mass. [20] System according to one of claims 13 to 19, wherein a proportion of the second transparent liquid in the application preparation is 50 to 95% by mass and in particular 60 to 90% by mass. [21] System according to any one of claims 13 to 20, wherein the mass ratio of the first transparent liquid to the second transparent liquid is 1 : 1 to 1 :

19. [22] System according to one of the preceding claims, wherein the application preparation has a dynamic viscosity, measured at 25 °C, in a range of 2 mPa·s to 40 mPa·s, in particular from 3 mPa·s to 35 mPa·s. [23] System according to any of the preceding claims, wherein the first layer comprises a plastic-based medium, a fiber-based medium or a textile-based medium. [24] System according to claim 23, wherein the motif is applied, in particular printed, to the plastic-based medium, the fiber-based medium or the textile-based medium. [25] System according to one of the preceding claims, wherein the motif is formed in one or more colors. [26] System according to one of the preceding claims, wherein the second hydrochromic layer is formed from a dried hydrochromic ink applied to the first layer. [27] System according to claim 26, wherein the hydrochromic ink comprises at least one solvent, at least one binder and at least one pigment, wherein the binder is in particular selected from acrylic resins, alkyd resins, polyurethane resins and polyester resins and wherein the pigment is selected from sodium aluminum silicates, amorphous silicas, clay, gypsum, aluminum oxides, talc and metal carbonates. [28] System according to one of the preceding claims, wherein the second hydrochromic layer is a layer applied by a screen printing process. [29] System according to any of the preceding claims, wherein the first transparent liquid has a vapor pressure of less than 1000 hPa at 20 °C. [30] System according to one of the preceding claims, wherein the application preparation is provided in a writing instrument or a painting instrument. [31] System according to one of the preceding claims, wherein the image template comprises a barrier layer below the first layer or between the first layer and the second hydrochromic layer. [32] System according to one of the preceding claims, wherein a transparent film (4) is arranged between the first layer (1) and the second hydrochromic layer (3). [33] System according to claim 32, wherein the transparent film (4) is a plastic-based film comprising in particular a polyolefin and in particular polypropylene or a copolymer of polypropylene. [34] System according to claim 32 or 33, wherein an adhesive layer (5) is provided between the transparent film (4) and the first layer (1) or wherein the transparent film (4) is self-adhesive on a surface facing the first layer (1). [35] System according to claim 34, wherein the adhesive layer (5) comprises an acrylate-based adhesive, a pressure-sensitive adhesive, a hot melt adhesive or a light-cured adhesive. [36] Use of an application preparation described in any one of claims 1 to 22 for producing a permanent image from an image template, comprising a first layer having at least one motif and a second hydrochromic layer arranged on the first layer.