(19) TZZ Z_T (11) EP 2 805 656 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 26.11.2014 Bulletin 2014/48 A47J 45/06 (2006.01) (21) Application number: 13168624.8 (22) Date of filing: 21.05.2013 (84) Designated Contracting States: (72) Inventors: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB • Juan Tahta, Alexis GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO Medellín (CO) PL PT RO RS SE SI SK SM TR • Restrepo Zea, Alejandro Designated Extension States: Medellín (CO) BA ME (74) Representative: Curell Suñol S.L.P. (71) Applicant: Landers y Cia S.A. Via Augusta 21 Medellin (CO) 08006 Barcelona (ES) (54) Kitchenware with thermochromic and photochromic inks applied in high visibility areas as thermal state indicator mechanism (57) Kitchenware comprising thermochromic and photochromic inks in zones of high visibility for the user are dis- closed, as a mechanism to know by simple observation their thermal state (cold or hot), independently if said kitchenware is used outdoors (under sunlight exposure) or in enclosed areas. Said kitchenware corresponds to pots, frying pans, cooking pots, pressure cookers, etc. able to be in direct or indirect contact with a thermal energy source and therefore able to reach a dangerous temperature for the physical integrity of the persons handling it. Thermochromic and photo- chromic inks are applied in zones of the kitchenware where the user may easily see the color change during use, as in zones where there is no direct contact with food. This novel system allows using safely that kitchenware showing variable temperature during their manipulation and use, independently if it is outdoors (under sunlight exposure) or in enclosed areas, also achieving a greater useful life of the incorporated thermochromic and photochromic points due to their strategic localization in the kitchenware. EP 2 805 656 A1 Printed by Jouve, 75001 PARIS (FR) (Cont. next page) EP 2 805 656 A1 2 1 EP 2 805 656 A1 2 Description turn visible. However, said change is reversible because the photochromic inks turn back to their original colorless [0001] The present invention refers to kitchenware state once they are separated of the light source. (pots, frying pans, cooking pots, pressure cookers or any [0007] Photochromic inks are mainly used in trade- other kitchenware whose use implies having direct or in- 5 mark and specific products marketing, given that its ver- direct contact with a thermal energy source and that may ification is immediate and it does not require any special reach a temperature that is dangerous for the physical equipment, only sunlight exposure. integrity of the persons manipulating it) comprising ther- [0008] Now, while the use of photochromic inks ad- mochromic and photochromic inks applied in areas of hered to kitchenware surface is not known in the state of high visibility for the user and are not in direct contact 10 the art, regarding the use of thermochromic inks as op- with food, as an indicator mechanism of the temperature tical indicators of the thermal state of said kitchenware, of said kitchenware that is easily observable by the user French patent FR 1388029 teaches kitchenware -for in- and therefore allows eliminating or at least reducing ac- stance, a frying pan-, comprising a thermochromic indi- cidental burns, independently if said kitchenware is used cator point on the internal cooking surface as a mecha- outdoors (under sunlight exposure) or in enclosed areas. 15 nism to indicate the user that said kitchenware is hot enough and that therefore it is the moment to add the Technical Background food to be cooked. According to the authors of said prior art document, the invention disclosed there is mainly ori- [0002] Thermochromic inks are chemical substances ented to be used on kitchenware susceptible of under- characterized because they undergo a color change (re- 20 going excessive heating, with the possible consequence versible or irreversible) as a result of a temperature of impairing or render useless food submitted to cooking. change. Generally, printed thermochromic inks are color- [0009] Unfortunately, although the application of ther- ed under the transition temperature and change to trans- mochromic inks on the internal surface of a recipient al- parent or to a clearer color when they are heated above lows knowing the temperature in the cooking surface, it the transition temperature range. 25 is absolutely known that its observation by the user is [0003] These inks are available in several colors and invalid, in practice, once the food to be cooked has been activation temperatures, being the activation tempera- added, with which the warning function of the thermal ture the temperature above which the ink changes com- state of said recipient is completely lost, for the cook and pletely to its final transparent or clear color point. Color for any other unprepared user, who may be then using starts changing approximately at 4° C below the activa- 30 it in inappropriate manner leading to potential risks for tion temperature. Examples of activation temperatures their physical integrity. are 15 °C, 31 °C and 45°C. However, nowadays thermo- [0010] On the other hand, it is also known in the state chromic inks with activation temperatures in the range of the art that there are kitchen recipients which incorpo- between -5°C and 65°C are known. rate mechanisms to indicate the internal surface temper- [0004] If the color change is irreversible, the thermo- 35 ature of the recipients, and wherein said mechanisms chromic inks recover their original color after being sub- generally comprise a temperature sensor integrated to mitted to a cooling process which allows reducing the the bottom of the kitchenware and connected to an elec- temperature below the transition temperature. However, tronic module including a screen to show the temperature if color change is irreversible, only one color change may measured by the sensor. Said mechanisms allow, in- be present. 40 deed, the user to determine the precise moment at which [0005] Both types of thermochromic inks have different the cooking surface has achieve the proper temperature uses in industry and research. Then, for instance, the to cook food, and also warn the user of the thermal state irreversible thermochromic inks are useful for proving of said kitchenware. that a product has not been submitted to any extreme [0011] However, the mechanism above is not conven- temperature during transport and/or storage, or to cor- 45 ient because of its complexity, especially related to the roborate that a surgical instrument has been submitted electric system used, its contact with water or any other to an efficient sterilization process. On the other hand, fluid is evidently inappropriate. reversible thermochromic inks are mainly used as optical [0012] According to the above, it is absolutely clear indicators in drinks, equipment and medicines, as well that there was a need in the state of the art for developing as in applications related to advertisement, because the 50 products for cooking food which allow the optimal use of color change that they may undergo when in contact with thermochromic and photochromic inks as temperature an energy source as the body heat allows it to be used indicators, ensuring its full visibility by the user independ- in books, cards and envelopes of great attraction for the ently if the use is made outdoors or in enclosed areas, general public. and also increasing stability and duration. [0006] On the other hand, photochromic inks are char- 55 acterized because they change color when they are ex- Basic features of the invention posed to sunlight or UV light. In its natural state are color- less or invisible and when they are exposed to heat they [0013] Now, taking into account the teachings of the 3 3 EP 2 805 656 A1 4 state of the art above and based on the technical features chromic and photochromic inks have changed color of the different types of products for cooking food with because of a temperature or sunlight exposure. mechanisms for the determination of the thermal state known so far, the applicant of the studied invention has FIGURE 3a is a schematic view of a pot according developed novel kitchenware with thermochromic and 5 tothe presentinvention, to whichthermochromic and photochromic inks applied in high visibility zones as an photochromic inks have been applied in zones of indicator mechanism of the thermal state. high visibility for the user and that are not in contact [0014] In this sense, the applicant of the studied inven- with food. FIGURE 3b is a comparative schematic tion developed kitchenware comprising thermochromic view of the pan when the thermochromic and pho- and photochromic inks in zones of high visibility for the 10 tochromic inks have changed color because of the user, as a mechanism to know by simple observation temperature increase or sunlight exposure. their thermal state (cold or hot), independently if their use is outdoors or in enclosed areas, and wherein said kitch- FIGURE 4a is a schematic view of a cooking pot enware corresponds to pots, frying pans, cooking pots, according to the present invention, to which thermo- pressure cookers or any other kitchen utensil whose use 15 chromic and photochromic inks have been applied implies indirect or direct contact with a thermal energy in zones of high visibility for the user and that are not source and that therefore may reach a temperature that in contact with food. is dangerous for the physical integrity of persons manip- ulating it. FIGURE 4b is a comparative schematic view of the [0015] Thermochromic and photochromic inks are ap- 20 cooking potwhen the thermochromicand photochro- plied in zones of the kitchenware where the user may mic inks have changed color because of the temper- observe easily the change of color during use, as in zones ature increase or sunlight exposure.