FR2818362A1 - Recipient containing compound which emits heat or stores cold has visual indicator of temperature state - Google Patents

Abstract

The recipient (1), made from two joined half-shells of a supple plastic material and containing a compound which emits heat or one which stores cold, incorporates a visual indicator to show when it has passed a pre-set temperature threshold. The indicator consists of at least one organic solution with a crystalline structure which changes colour at the predetermined temperature, e.g. liquid crystal solution. The heat emitting compound is a mixture of sodium acetate and water with an exothermic reaction activator; the cold accumulating compound is a gel with ingredients mixed in proportions to maintain a gel state in a temperature range of 0 to -40 deg C.

Description

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Container containing a composition capable of restoring heat or a cold-accumulating composition
The present invention relates to a container containing a composition capable of restoring heat or a cold accumulating composition.

 It is known in the prior art containers with a thermal effect, for example for creating heat. By way of example, French patent application FR 2 569 979 describes a device for triggering by the activation of an aqueous saline solution, intended for use in a buffer with thermal effect, also called a heater. Activation of the aqueous solution causes an exothermic reaction which provides heat for a specified period of time.

 Likewise, reusable ice cubes are known which are formed from a container filled with a liquid which accumulates cold. The principle of cold accumulation can be based on the phase change of the liquid. Thus, water or an aqueous solution can be chosen as the cold accumulating liquid.

 The major drawback of these devices is that it is difficult for the user to determine when the thermal effect of the container is insufficient for the desired application. Thus, a user cannot be sure at all times that the cold returned by a reusable ice cube is sufficient, for example, to maintain a temperature below 4 ° C. in an enclosure.

Indeed, between the moment when the reusable ice cube is removed from the cold source in which it has accumulated cold and the moment when all the cold accumulated by the reusable ice cube is completely restored, the user cannot determine when the ice does not return enough cold.

 The previous example also applies to the heater.

 The present invention therefore aims to overcome the drawbacks of the prior art by providing a container of an accumulator composition of

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 heat or a cold storage composition to indicate the level of use of heat or cold accumulated by the composition.

 This object is achieved by a container containing a composition capable of restoring heat or a cold-accumulating composition, the container being sealed and characterized in that it comprises a closed internal volume delimited by an external envelope, the external envelope of the container comprises two half-shells made of flexible plastic material, the two half-shells being joined to one another by their periphery to form the interior volume comprising the composition of the container.

 The invention, with its characteristics and advantages, will emerge more clearly on reading the description made with reference to the accompanying drawings in which: - Figure 1 shows a front view of an embodiment of a container according to the invention, - Figure 2 shows a side view of an embodiment of a container according to the invention.

 - Figures 3A to 3D show a front view of different possible shapes for the container according to the invention.

 The container according to the invention will now be described with reference to FIGS. 1 and 2.

 The container (1) according to the invention is intended to contain a composition capable of restoring heat or a cold accumulating composition. The container therefore comprises an outer envelope (10) defining an interior volume which contains the composition. The composition is, for example, of a type known to those skilled in the art.

 Thus, an example of a composition capable of restoring heat is given in patent application FR 2 770 627. The composition is a metastable solution with phase change. The phase change is accompanied by a release of heat.

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 Patent application FR 2 770 627 provides an example of a supercooled liquid such as a sodium acetate solution. The phase change is triggered by an activator embedded in the solution.

 Likewise, many cold accumulating compositions are known. The best known is an aqueous solution such as a water / alcohol mixture or a eutectic mixture.

 In an alternative embodiment, the cold storage composition is a gel which complies with food standards and the proportions of which are chosen so that the gel retains its viscosity, even for temperatures below 0 C. Thus, the proportions of the constituents of the gel can be determined so that the viscosity of the gel remains substantially constant up to a determined temperature, for example between -40 and 0 C.

 The outer casing (10) is formed by two half-shells (11,12) of plastic material assembled by their periphery. Each half-shell (11, 12) consists of a flexible plastic film assembled on its periphery (13) by a welding process.

 According to an alternative embodiment, the welding process is microwave welding. To do this, the material constituting the half-shells (11,12) is a material compatible with microwave welding. According to an alternative embodiment, the material chosen is PVC or polyurethane (PU). Similarly, in another alternative embodiment, the material and the production line of the container according to the invention are of food grade. Thus, the container (1) according to the invention contains a cold storage composition and can be used, for example, in the cold chain.

 Microwave welding overcomes the disadvantages of filling the outer casing (10). Indeed, during the filling of the envelope, composition or gel residues can drool on the periphery of the half-shells (11,12). The microwave welding allows even with the presence of burrs, to obtain a perfect seal of the assembly of the two half-shells (11,12). Microwave welding

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 reduces the rim due to the weld in proportions of 1 to 3 compared to traditional welds. Microwave welding thus makes it possible to reduce the unsightly side of the large rim associated with other welding processes.

 Other assembly methods can be used to assemble the two half-shells. Thus, for example, ultrasonic welding or thermal welding are possible joining methods.

 The general shape of the half-shells forming the outer casing (10) is, for example, a disc. This shape facilitates the microwave welding operation. However, as shown in Figures 3A to 3D, other shapes can be chosen depending on the desired application. According to the invention, the shape chosen for the half-shells is a closed contour formed by a succession of curves. Thus, one can choose as shape a rectangle whose angles are rounded and whose sides are either curved or swollen.

 Similarly, when the container (1) according to the invention is used as a cooling element, the plastic material chosen to produce the outer casing (10) is flexible and the accumulating composition is, for example, a gel which remains liquid, even at temperatures below 0 C. Thus, the flexibility of the envelope and the texture of the gel allow the container (1) according to the invention to have more contact surface with the product to be refrigerated by closely fitting the shape of the product to be refrigerated. Thus, the heat transfer between the cold storage gel and the product to be refrigerated is greater, which allows better cooling of the products to be refrigerated.

 According to the invention, the container (1) comprises means (2) for visual indication of an overshooting of at least a determined temperature threshold.

 According to an alternative embodiment, these visual indication means comprise at least one organic solution with a crystalline structure to which organic or non-organic compounds having thermochromic behaviors are associated. In the following description this

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 solution is called thermochromic solution. A thermochromic solution has the distinction of having a first color in a first determined temperature range and a second color visibly distinct from the first in a second determined temperature range. Thus, by way of example, a cobalt chloride solution is pink in color when its temperature is below 35 ° C. and it is blue in color when its temperature is above 35 ° C. A nickel sulphate solution is green in color when its temperature is below 155OC and it is yellow in color when its temperature is above 155OC. Other thermochromic solutions are known in the prior art which have color change temperatures between -30 and + 155OC.

 According to the invention, at least one thermochromic solution is mixed with the heat or cold storage composition in a determined proportion. The proportion of thermochromic solution in the composition is chosen in particular as a function of the intensity and of the color gardian which the user wishes to obtain at given temperatures. In this alternative embodiment, the outer casing (10) of the container (1) is made in whole or in part with a translucent or transparent material, so that the color change of the mixture formed by the composition and the thermochromic solution, either visible from the outside. For example, the material chosen is "crystal" PVC.

 According to another alternative embodiment, a thermochromic solution is mixed with a solvent to form a so-called thermochromic ink which will then have the same characteristics as the thermochromic solution with regard to the color change. The thermochromic ink can be produced from a mixture of at least two thermochromic solutions. The ink thus produced is then used to print at least one pattern (2) on the outer surface of the container (1).

 Consequently, the printed pattern (2) will change color depending on the temperature range in which the temperature of the

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 container (1). So that the printed motif (s) (2) are more legible, it is preferable to choose a plastic material of contrasting color with the colors of the ink to make the outer envelope (10). Another solution consists in using a translucent or transparent material to make the outer envelope (10) and in tinting the composition with a contrasting color compared to the colors of the ink printed on the outer envelope (10).

 The pattern (2) printed on the outer surface of the container (1) is, for example, a written message of the alert message type "temperature X reached" or an advertising message, such as a logo. Likewise, the printed pattern can be a symbol representing the temperature range. Thus, in an exemplary embodiment, the thermochromic solution is chosen so that a color change takes place around 4 cl. In this case, the pattern could be a snow crystal.

 In another alternative embodiment, the thermochromic solution is chosen so that the color change when changing the temperature range is irreversible. Thus, as soon as the first color change is effective, the color of the solution, that is to say the color of the pattern or the color of the cold or heat accumulating composition, will no longer change color even if the temperature changes the temperature range again. The use of this type of "irreversible" thermochromic solution makes it possible to use the container (1) according to the invention as a temperature tracer, for example in a cold chain. Thus, if in a food chain the temperature must never be higher than a determined critical value, it suffices to choose a thermochromic ink whose color change takes place at this determined critical temperature. Then, it suffices to place one or more containers (1) according to the invention near foods whose temperature must be controlled. If, for example, during the transport chain of the food to be checked, the temperature of the latter exceeds the critical temperature, the color of the container (s) or printed pattern will

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 irreversibly change. A user can see simply and visually that an incident has occurred in the cold chain and that the food is, therefore, unfit for consumption.

 In another alternative embodiment, means for visual indication of a breach of at least a determined temperature threshold comprise a plastic material having substantially the property of having a first color in a first determined temperature range and a second color, visibly distinct from the first, in a second determined temperature range. This plastic material is then used to produce, in whole or in part, the outer casing (10) of the container (1). The effect obtained is then substantially the same as for the variants using a thermochromic solution. Thus, depending on the temperature, the plastic material has a different color, which allows the user to simply view the state of the heat or cold storage composition enclosed in the container.

 In another alternative embodiment, the thermochromic solution is micro-encapsulated before being mixed with the composition contained in the container. Likewise, the thermochromic solution is micro-encapsulated and then mixed with a solvent to form an ink intended to write a message on the envelope of the container.

 In another alternative embodiment, the visual indication means comprise a liquid crystal solution, for example, of the type used to make the aquarium thermometers. This liquid crystal solution can either be incorporated into the composition or placed on the envelope.

 Thus, a first type of application of the container (1) according to the invention provided with means (2) for visual indication is, for example, to visually indicate to a user the state of the heat accumulating composition or cold enclosed in the container (1) according to the invention.

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 A first application of this type consists in making reusable ice cubes with the container (1) according to the invention. To do this, we will choose the variant where the thermochromic solution is mixed with the cold storage composition and where the material of the outer casing (10) is translucent or transparent. We will also choose a thermochromic solution which changes color around 4 cl. Thus, when the reusable ice cubes produced according to the invention are used, for example to refrigerate a food stall at a temperature below 4 ° C., as soon as one or more ice cubes are no longer at the correct temperature, that is to say say below 4 cl, these change color. The user can therefore replace the ice cube (s) which have changed color with colder ice cubes which have the initial color indicating that they have a temperature below 4 cl.

 The container (1) can be used as a simple temperature indicator. Thus, when it is desired to verify that an enclosure is at a temperature included in a determined temperature range, it will suffice to choose the thermochromic solution (s) so that the container has a unique color in the determined temperature range and a color different when the enclosure temperature is no longer in the determined temperature range. Thus, without the help of a thermometer, a user visually checks whether the temperature of an enclosure is in the correct temperature range.

 Thus, a second type of application of the container (1) according to the invention provided with means (2) of visual indication is, for example, to serve as an original advertising medium. Indeed, in this case, it suffices to choose one or more logo or one or more advertising messages as a motif, which will either change color, or appear or disappear depending on the temperature of the composition contained in the container.

 To do this, the container (1) uses, alone or in combination, all of the examples of means for visual indication of a violation of at least a determined temperature threshold described above, namely a mixture

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 formed of at least one thermochromic solution and of the composition contained in the container, at least one thermochromic ink printed on the external surface of the container or a plastic material with thermochromic properties to produce all or part of the external envelope (10).

 In a third application, the container (1) according to the invention is used to make a heater. In this application, the container (1) comprises, for example, a mixture of water and sodium acetate. The outer envelope is made of transparent or translucent PVC. The mixture also includes two thermochromic solutions and optionally a dye.

 It is known that during the phase change of sodium acetate the temperature of the container can reach about 55 ° C. Similarly, to return the sodium acetate to liquid form after use, the container must be brought to a temperature above 80 ° C. However, the envelope material is PVC which deteriorates beyond 100OC and does not withstand high temperatures for long periods.

 Thus, in this example, we will choose a first thermochromic solution which changes color between 40 and 50 C in order to indicate to the user that the exothermic reaction of phase change takes place.

The second thermochromic solution is chosen so that it changes color between 70 and 80 C to indicate to the user that the temperature of return to liquid form is reached and that it is no longer necessary to continue heating the container. .

 According to another variant of the invention, the container comprises photosensitive means incorporated into the solution or applied to the envelope so as to create a visual effect as a function of the wavelength of the surrounding light. The photosensitive means are, for example, a compound or a solution which changes color as a function of the light radiation which it receives, or a compound or a phosphorescent solution. Thus, by adding the photosensitive compound or solution to the composition contained

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 in the container, a visual effect is obtained as a function of the light radiation illuminating the container (1).

 In another alternative embodiment, the photosensitive solution is micro-encapsulated before being mixed with the composition contained in the container. Likewise, the photosensitive solution is micro-encapsulated and then mixed with a solvent to form an ink intended to write a message on the envelope of the container.

 Thus, the container (1) according to the invention is characterized in that it comprises a closed internal volume delimited by an external envelope (10), the external envelope (1) of the container (1) comprises two demicoques (11, 12) made of flexible plastic material, the two half-shells being assembled to each other by their periphery to form the interior volume comprising the composition of the container (1).

 According to another embodiment, the flexible plastic material is food-grade PVC and the assembly of the two half-shells is carried out by high frequency welding on the periphery (13) of the two half-shells (11,12).

 According to another embodiment, the container comprises means (2) for visual indication of an overshooting of at least a determined temperature threshold.

 According to another embodiment, the visual indication means comprise at least one organic solution with a crystalline structure to which are associated determined organic or non-organic compounds having thermochromic behaviors, a solution, called thermochromic, having the characteristic of have a first color in a first determined temperature range and a second color visibly distinct from the first in a second determined temperature range.

 According to another embodiment, the thermochromic solution (s) are mixed with the composition enclosed in the container

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 and the material constituting the material constituting the container is translucent or transparent over at least part of its outer surface.

 According to another embodiment, each thermochromic solution is mixed with a solvent to form an ink, so as to form with each ink, at least one pattern (2) determined on the outer surface of the container (1).

 According to another embodiment, the visual indication means comprise a plastic material which has the characteristic of having a first color in a first tranche of determined temperature and a second color, visibly distinct from the first, in a second tranche of determined temperature, this material being used to make at least part of the envelope (10) outside of the container (1).

 According to another embodiment, the visual indication means comprise a compound which has the characteristic of having a first color in a first determined temperature range and a second color, visibly distinct from the first, in a second temperature range determined, and retains its color after the first change in temperature range, so that one or more changes in temperature range do not cause a change in color.

 According to another embodiment, the visual indication means comprise a liquid crystal solution.

 According to another embodiment, at least one pattern (2) printed on the outer surface of the container (1) is an advertising message.

 According to another embodiment, the composition is a gel capable of accumulating cold, the components of which are mixed in determined proportions so as to remain in the gel state up to a temperature of between 0 and -40 ° C.

 According to another embodiment, the composition is a mixture of sodium acetate and water in which is embedded an activator of the exothermic reaction of phase change of sodium acetate.

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 According to another embodiment, the container comprises a photosensitive compound or solution added to the composition contained in the container or applied to the outer envelope of the container to create a visual effect as a function of the light radiation illuminating the container (1).

 It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of the invention as claimed. Therefore, the present embodiments should be considered by way of illustration, but may be modified in the field defined by the scope of the appended claims, and the invention should not be limited to the details given above.

Claims (13)

1. Container (1) containing a composition capable of restoring heat or a cold accumulating composition, the container being sealed and characterized in that it comprises a closed internal volume delimited by an external envelope (10), the envelope (1) outer of the container (1) comprises two half-shells (11,12) made of flexible plastic material, the two half-shells being joined to each other by their periphery to form the internal volume comprising the composition of the container (1).  2. Container according to claim 1, characterized in that the flexible plastic material is food-grade PVC and the assembly of the two half-shells is carried out by high frequency welding on the periphery (13) of the two half-shells (11 , 12).  3. Container according to claim 1, characterized in that the container comprises means (2) for visual indication of an overshooting of at least a determined temperature threshold.  4. Container according to claim 3, characterized in that the visual indication means comprise at least one organic solution with a crystalline structure to which are associated determined organic or non-organic compounds having thermochromic behaviors, a solution, called thermochromic, having the characteristic of having a first color in a first tranche of determined temperature and a second color visibly distinct from the first in a second tranche of determined temperature.  5. Container according to claim 4, characterized in that the thermochromic solution or solutions are mixed with the composition enclosed in the container and the material constituting the material constituting the container is translucent or transparent over at least part of its outer surface. <Desc / Clms Page number 14>  6. Container according to claim 3 or 4, characterized in that each thermochromic solution is mixed with a solvent to form an ink, so as to form with each ink, at least one pattern (2) determined on the outer surface of the container ( 1).  7. Container according to one of claims 3 to 6, characterized in that the visual indication means comprise a plastic material which has the characteristic of having a first color in a first determined temperature range and a second color, visibly distinct from the first, in a second determined temperature range, this material being used to produce at least part of the envelope (10) outside the container (1).  8. Container according to one of claims 3 to 7, characterized in that the visual indication means comprise a compound which has the characteristic of having a first color in a first determined temperature range and a second color, visibly distinct of the first, in a second determined temperature range, and retains its color after the first change of temperature range so that one or more changes of temperature range do not cause any change in color.  9. Container according to one of claims 3 to 8, characterized in that the visual indication means comprise a liquid crystal solution.  10. Container according to claim 6, characterized in that at least one pattern (2) printed on the outer surface of the container (1) is an advertising message.  11. Container according to one of claims 1 to 10, characterized in that the composition is a gel capable of accumulating cold, the components of which are mixed in determined proportions to remain in the gel state up to a temperature included between -0 and -40 C. <Desc / Clms Page number 15>  12. Container according to one of claims 1 to 10, characterized in that the composition is a mixture of sodium acetate and water in which is embedded an activator of the exothermic reaction of phase change of the acetate of sodium.  13. Container according to one of claims 1 to 12, characterized in that it comprises a photosensitive compound or solution added to the composition contained in the container or applied to the outer envelope of the container to create a visual effect depending light radiation illuminating the container (1).