ES1225956U - THERMOCROMIC CONTAINER FOR DEPILATORY COMPOSITIONS (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A container for depilatory compositions, which is made of a plastic material, characterized in that said container comprises in its composition at least one thermochromic material containing two or more reversible thermochromic compositions, the first in a concentration comprised between 0.1 and 8% and the second in a concentration between 0.05% and 8% by weight of the total weight of the thermochromic material, both being sensitive to heat at a temperature higher than 40ºC but different from each other, in such a way that the first of them is sensitive to heat in a temperature interval lower than the second. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

THERMOCROMIC CONTAINER FOR DEPILATORY COMPOSITIONS

Object and technical sector of the invention

The invention is part of the field of cosmetics, specifically epilation, and is directed to a container with thermochromic properties for depilatory compositions.

BACKGROUND OF THE INVENTION

Many different products are known in the field of hair removal to eliminate superfluous body hair, apart from shaving. One type of composition, the most common, requires initial heating before being applied to the skin in a generally molten state, being known as hot waxes. Once applied, it is allowed to solidify before being removed from the skin along with the unwanted hair. This is known in the art as an epilation, since the hair is pulled from the skin to the root (patent ES2442918 T3). They can also be found in the prior art, being of common use, warm waxes in which there is also a previous heating but at a lower temperature and wax bands that extend and apply in the area to be removed, which use a support material to facilitate its withdrawal (international application WO9730608 A1; ES2123430 B1).

Some of the most innovative compositions are in the form of emulsion or cream, and can be applied to the skin, at room temperature. The cream includes a substance that degrades the hair keratin. Conventionally, said compositions are applied to the skin in areas where unwanted hair is present, leaving them in that area for a predetermined time to allow the keratin of the hair to degrade. Finally, the composition together with the degraded hair are removed from the skin, usually with an instrument such as a sponge or a spatula that drags it. Such compositions are known in the art as depilatory creams (patent EP2355788 B1).

Depilatory wax compositions, which require prior heating, can cause burn problems if the necessary precaution is not taken and the methods of use are not adequately followed, especially in hot waxes.

Normally the problem of these waxes is usually given because the consumer does not have a reference of the temperature reached by the wax until it is used on the body, producing burns. Thus, the products that exist in the market or not inform the consumer of the temperature change of the product to be applied or only inform when the temperature of use or non-use has been reached. However, they do not report the temperature at which it should be used for adequate temperature and should not be used for excessive heating in the same product. One example is found in patent ES2189990, where a depilatory wax container is described that includes an applicator with a thermochromic compound to indicate the application temperature, which changes color between 40 ° C and 60 ° C. However, the invention described in ES2189990 has limitations: within the waxes that need heating, there are liposoluble waxes and water-soluble waxes, and the applicator with a thermochromic compound does not work correctly for the former, since it does not allow to correctly visualize the pigment change in repeated uses for the wax film that remains in the applicator during use.

To solve the problems detected in the state of the art, and avoid possible burns with these depilatory products, a container has been developed that informs by simple observation to the consumer of the moment in which he can make good use of the wax and in which It is recommended to be at inadequate temperature conditions, either low or very high. The packaging proposed here has this information available to the user through a triple color change and the intensity of said color:

- In its origin, the product can not be used and the color of the container at room temperature is observed;

- In the first color change due to the change in one of the pigments, the product is suitable for use; Y

- When certain areas of the container begin to appear in which the color changes again to a different one due to the change in color of a second pigment, the product is too hot in those areas and there is a risk of burns, so it is advisable not to use until tempered.

General description of the invention

The present invention relates to a container for depilatory compositions (as are preferably warm waxes and hot waxes), which is made of a material plastic having thermochromic properties, characterized in that said plastic container comprises in its composition at least one thermochromic material (dye type, for example masterbach, called in Spanish master dye) which contains two or more thermochromic or reversible thermosensitive compositions (pigments), the first in a concentration of 0.1-8% and the second in a concentration of 0.05% -8% by weight of the total weight of the thermochromic material, both being sensitive to heat at a temperature higher than 40 ° C (yet cold for the application of the wax) but different from each other, in such a way that the first of them is sensitive to heat in a temperature interval lower than the second.

Thanks to the thermochromic properties of the container object of the invention, said container shows the ability to change color according to the temperature applied to it, after its heating. Since the container is specially designed to contain depilatory compositions, such as waxes that must be heated for use, the purpose of the color change and its intensity is to warn the consumer of the temperature that the container acquires when heated, in such a way that by simple observation it is possible to check its temperature to know if it is ideal for the use and / or application of the wax it contains.

The type of plastic material for the wax container is not particularly limited. However, the material from which the package is made can be of many different types of plastics, preferably selected from the group consisting of: polypropylene (PP), polyethylene (PE), polystyrene (PS), polycarbonate and a combination thereof . Preferably, it is manufactured at a maximum temperature of 200 ° C.

The depilatory composition is preferably a warm or hot depilatory wax. It should be understood that any embodiment of the container, where the pigments are added, is adapted to the product it contains, that is, depending on the temperature suitable for use or the excess temperature for each type of wax used, in such a way that adjusts the composition of the thermochromic material according to the temperature of use.

In this way, the thermochromic material is not particularly limited to a specific or specific type; the only condition, by the nature of the invention itself, is that said thermochromic material must change color and intensity of said color in a appropriate temperature range, which is determined by the wax contained in the container. Preferably, the first pigment is contained in the thermochromic material in a concentration comprised between 0.5 and 5% and the second pigment in a concentration of 0.1% -5% by weight of the total weight of the thermochromic material. When it is indicated in the present specification that the pigment or composition is sensitive to heat at a certain temperature, it is meant that that pigment changes color from its original coloration at room temperature to another coloration, even disappearing its coloration, by stimulation to the indicated temperature. When using (at least) a dye with two compositions or heat-sensitive pigments, the container can show at least three colors depending on the temperature applied in the heating of the container, namely: 1) the color formed by the own base color of the container plus that of the dye formed by the two thermochromic pigments at room temperature (understood as ambient temperature as that comprised between 25 ° C - 30 ° C); 2) a characteristic color after the disappearance or modification of the color of one of the thermochromic pigments when a temperature that is suitable for the application of the wax is applied; and 3) a characteristic color after the disappearance or modification of the color of the second of the thermochromic pigments when a temperature which is too high for the application of the wax is applied.

Preferably, the upper temperature limit at which the first pigment totally changes color and reaches the maximum level of said change (the acquired color is homogeneous) coincides with the lower temperature limit at which the second pigment begins to change color.

The first pigment, which is the one that changes color at a temperature lower than the second, responds to temperatures equal to or greater than 40 ° C. Suitable temperature for the application of the wax (preferably warm or hot) is understood to be between 42 ° C-64 ° C depending on the kind of wax. In the most preferred embodiment, the first pigment changes color at a temperature comprised between 40 ° C and 64 ° C. ° C and 65 ° C, while the second pigment changes color at a temperature between 45 ° C and 70 ° C.

It is evident that the container acquires a temperature with the heating different (lower) than the one that acquires the own wax that it contains. In this way, for example, the Container, depending on its thickness and the formulation of the wax it contains, usually acquires a temperature between 1 ° C-11 ° C less than the wax it contains.

Obviously, the essence of the invention is the double color change of the container as the heating temperature varies, reporting the appropriate time of use and the prevention of non-use; in this way, the type of color that informs of these moments is secondary, and depends on the type of thermochromic material chosen. However, in a particular preferred embodiment, the package with the coloring composition is purple at room temperature; the color of the first pigment disappears and the container changes to pink when the temperature is between 60-65 ° C and the color of the second pigment disappears and the container changes to white color (base color) when the temperature is equal or higher at 65 ° C, preferably above 70 ° C.

Based on the above considerations, there is a wide variety of thermochromic compositions or pigments that can be part of the thermochromic material of the plastic container, such as those described in US Patent 4,028,118, which document is incorporated by reference. The determining factor is that: a) these pigments change color at appropriate temperatures; b) changing color at different temperatures, between the two covering the temperature range of interest for the object of the invention, and c) changing color over a wide range of temperatures, as specified above.

Preferred embodiment example

The experimental results of tests performed with packages prepared according to the present invention are described below. The objective of the test is to check whether the containers with dye or ink with thermochromic pigments have an adequate behavior to change color at the desired times and conditions with warm wax or hot wax, and compare whether said behavior is the same with packaging of different geometry, materials, capacity and colors.

Process

The package is purple at room temperature, while changing to pink at the appropriate temperature of use (by change or disappearance of the color of the first pigment) and white when it is too hot for its application (due to change or disappearance of the color of the second pigment).

Three containers according to the invention were used, of various geometries and capacities (100 grams, 250 and 400 grams) and were filled with two types of liposoluble wax, allowing to cool before beginning the tests. Subsequently, the wax was heated, following the instructions for the use of the wax and subsequently at successive intervals of 20 seconds of heating with 20 seconds of rest. To heat the package, a Daewoo 800W microwave was used. The temperature of the wax was measured with a laboratory thermometer and the temperature of the walls of the container was measured with an infrared thermometer.

Results

The results with the filled containers of 100g, 250g and 400g of wax can be seen in the following table:

Table 1 - Behavior of the containers according to the present invention and of the waxes they contain as a function of temperature

conclusion

After the results obtained it was concluded that the containers presented an optimal behavior for the intended purpose. Both the color change of the container and the temperature of the wax in the 250g and 400g containers are a few degrees higher than those observed for the 100g container. This difference in the temperature of the container and the wax may be due to the homogenization of the product and the geometry and thickness of the container.

Thus, the package has a good performance regarding the change of color by temperature if the color code is adequately explained in the instructions for use:

- Wax suitable for depilation when the container presents a homogeneous pink color;

- At the moment when the white color begins to appear on the container, let the wax cool because it is too hot for its application.

These results can be extrapolated to other packaging formats of different capacity and geometries such as 250 ml jars and 120 ml bottles and other types of wax such as liposoluble or water soluble wax.

Claims (7)

A container for depilatory compositions, which is made of a plastic material, characterized in that said container comprises in its composition at least one thermochromic material containing two or more reversible thermochromic compositions, the first in a concentration comprised between 0.1 and 8% and the second in a concentration between 0.05% and 8% by weight of the total weight of the thermochromic material, both being sensitive to heat at a temperature higher than 40 ° C but different from each other, in such a way that the first of them is sensitive to heat in a temperature interval lower than the second. 2. The package of claim 1, wherein the plastic material from which it is made is selected from the group consisting of polypropylene, polyethylene, polystyrene, polycarbonate and any combination thereof. 3. The package according to any one of claims 1 or 2, wherein the depilatory composition is warm or hot depilatory wax. The package according to any one of the preceding claims, wherein the first pigment is contained in the thermochromic material in a concentration comprised between 0.5 and 5% and the second pigment in a concentration of 0.1% -5% by weight of the total weight of the thermochromic material. 5. The package according to any one of the preceding claims, wherein the upper temperature limit at which the first pigment completely changes color and reaches the maximum level of said change, producing a homogeneous color in the package, coincides with the lower limit of temperature at which the second pigment begins to change color. The package according to any one of the preceding claims, wherein the first pigment changes color at a temperature comprised between 40 ° C and 65 ° C, while the second pigment changes color at a temperature comprised between 45 ° C and 70 ° C. ° C. The package according to any one of the preceding claims, which has a purple color at room temperature; pink when the color of the first pigment disappears; and white color, when the color of the second pigment begins to disappear.