DE29612669U1 - Food container with temperature sensitive marking - Google Patents

Description

Schmalbach-Lubeca AG

10109a; Description

Food containers with temperature-sensitive marking

The present invention relates to the packaging of foodstuffs, in particular cold drinks, microwaveable foods and frozen goods.

A whole range of foods are consumed at a different temperature than they are stored at. Examples of this can be found in the beverage industry, where many drinks are enjoyed ice cold

&iacgr;&ogr;, while the temperature is not important for storage and, for cost reasons, this is therefore carried out at ambient temperature. Another example is ready meals that are stored sterilized or frozen, but are warmed or heated before consumption - preferably in a microwave oven. A third area is the preservation of food by cold, whereby it must be ensured that the permanent storage temperature does not exceed a certain maximum temperature in order to prevent the food from spoiling.

The aim of the present invention is to provide containers that display their own current temperature. In this way, the beer drinker can find out whether his beer is well chilled, the warehouse keeper or transporter of frozen goods can find out whether the maximum temperature of frozen goods has been exceeded during transport or if a cooling unit in the cold store fails, or not, and the housewife can find out whether the ready meal placed in the microwave is already at a comfortable temperature for consumption or whether it is even overheated.

The above-mentioned task is solved by applying thermochromic dye {thermochromic ink) to the respective food containers.

Schmalbach-Lubeca AG

\01Q9a; Description

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The term "food" in this case is intended to include everything that can be consumed by humans - and possibly also by pets - whether liquid or solid, whether prepared or raw. This includes, for example, drinks, ready-made products and the like.

The term "container" refers to all parts of the packaging containing the food, e.g. the base, side walls and lid, as well as any other parts such as brackets, handles or the like, in the closed and unsealed state, with or without a closure (lid).

A thermochromic dye ("thermochromic ink") is or contains one or more colors whose absorption spectrum or other physical, optically perceptible properties are dependent on the temperature, i.e. they change the absorbed wavelength or become cloudy/clear when the temperature changes. This makes the marking created with this color sensitive to the temperature of the container wall to which it is applied; it acts like a thermometer.

The dye marking to be applied is applied directly to the container, for example by spraying a solution or dispersion, using inkjet printing, screen or other printing or the like. The dye is preferably applied when the container has already been manufactured. It is convenient if the thermochromic color or colors for the respective marking are applied before the container is filled with the respective food.

To ensure that the paint adheres well to the substrate, a hardenable component is preferably added to it. The hardenable component can be provided, for example, as a coating on the dye particles or as an additive that wraps around the dye particles when heated and "sticks" them to the substrate. Furthermore, the medium in which

Schmalbach-Lubeca AG

\0\09a·, Description

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the dye is preferably dissolved or suspended and contains curable components. The dye can also be self-adhesive, e.g. a thermochromic, curable dye containing color-imparting groups.

After application, the paint or paints are cured if necessary (e.g. thermally or photochemically), whereby the curing temperature must of course not exceed the temperature at which the paint loses its &iacgr;&ogr; thermochromic properties (irreversibly).

The packaging is then filled and sealed in the usual way, for example by crimping a drinks can. Pasteurization also takes place in the usual way.

The marking can of course have any shape. It can be round or have another geometric shape, but it can also consist of or contain lettering or a figure. A particular advantage here is the fact that the surface to which it is applied does not have to be flat or smooth, as it is applied in liquid form. Rather, the marking can also be applied across grooves or, as in the example shown below, on concave (or otherwise curved) or otherwise uneven surfaces. Depending on the viscosity set, thicker, three-dimensional structures can also be achieved, which offer variety not only to the eye but also to the sense of touch.

In a preferred embodiment , a dye is chosen that looks white (colorless but opaque) at room temperature, while at temperatures at which cold drinks are usually consumed, the color changes to a darker tone. This is of course just an example. Depending on the chemical composition of the color, any variation can be achieved.

Sciimalbach-Lubeca AG

a·, Description

Figures 1 and 2 show a preferred embodiment of the present invention.

Figure 1 shows the lower part of a can as a grid diagram. One can see a concave

Can bottom with a centrally arranged, round marking 1.

Figure 2 shows a section through the can base of Figure 1; one can see the raised application of the

thermochromic dye 1 in the center of the can bottom.

The thermochromic dye is preferably applied to metal containers. Thermochromic paints with a hardener that cures at relatively low temperatures can also be applied to other materials, such as glass or plastic.

Claims (10)

Schmalbach-Lübeca. AG 10109a; Claims Claims: 1. A food container, characterized in that it has a temperature-sensitive marking made of thermochromic dye applied directly to its ready-to-use surface. 2. Food container according to claim 1, characterized in that it consists entirely or essentially of &iacgr;&ogr; metal. 3. Food container according to claim 1, characterized in that it is a beverage can. 4. Food container according to claim 1, characterized in that it is a beverage bottle. 5. Food container according to claim 1, characterized in that it is a microwave-safe food container. 6. Food container according to claim 3, wherein the beverage can has a concavely curved bottom and the temperature-sensitive marking is applied to this bottom curvature. 7. Food container according to one of the preceding claims, wherein the marking has a geometric shape. 8. Food container according to claim 7, wherein the marking is essentially dot-shaped and/or represents writing and/or a figure. 9. A food container according to claim 7 or 8, wherein the marking has a thickness of 0.1 to 1 mm. Schmalbach-Lubeca AG \0\09a; Claims 10. Food container according to one of the preceding claims, characterized in that the temperature-sensitive marking is applied to the container by spraying, ink-jetting or printing.