A temperature sensing warning indicator and a method for preparing the same

Abstract

The present invention discloses a temperature-sensitive warning indicator and a preparation method thereof, comprising a color-changing portion and an excitation portion; the color-changing portion comprises a base layer, a color ink layer and an opaque layer arranged in sequence; the excitation portion comprises a solvent layer and a covering layer arranged in sequence; the solvent layer is attached to the side of the opaque layer away from the color ink layer; when the temperature-sensitive warning indicator is above a set indication temperature range, the phase-changing solvent of the solvent layer changes from solid to liquid, and enters the color ink layer through the opaque layer, so that at least part of the color of the color ink layer migrates to the side of the opaque layer away from the color ink layer. The temperature-sensitive warning indicator of the present invention, when the temperature is higher than the phase change point, under the action of the liquid phase change material, the color of the color ink layer migrates to the side of the opaque layer away from the color ink layer, so that the color / pattern on both sides of the opaque layer changes, thereby detecting and recording whether the indicator is exposed to a temperature higher than the phase change point, and has the advantages of obvious color change, rich color pattern selection, and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature monitoring, and in particular to a temperature sensing warning indicator and a preparation method thereof. Background Art

[0002] At present, temperature-sensitive products such as food, medicine, and vaccines need to be controlled within a certain temperature range during production, transportation, and storage. Considering the complexity of the transportation and storage process, how to monitor these products during transportation and storage to ensure that they meet product design requirements (especially low temperature requirements) is an urgent problem to be solved by technical personnel in this field.

[0003] In the prior art, for example, the Chinese patent application number CN200420078916.0 mentions the use of the capillary action principle of a simple thermometer to make a device that can change color when the ambient temperature exceeds the set temperature. The device is relatively large in size while the cold chain product is relatively small in size, and the key components of the device are fragile and difficult to use. In addition, the British Timestrip company proposed a color-changing label device in the patent application number CN1533518A in China. After the capsule containing the solvent is crushed, the solution gradually penetrates into the observation area. Once used, it will become invalid in a few minutes or a few hours. It can only measure the cold chain transportation time, but not whether the cold chain environment exceeds the set dangerous temperature. At the same time, the product has the problems of complex structure, high cost, and large volume, which limits its promotion and application. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a temperature-sensitive warning indicator and a preparation method thereof, which utilizes the solubility of phase change materials in specific coatings / inks to perform color migration to achieve temperature indication.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A temperature-sensitive warning indicator comprises a color-changing portion and an excitation portion; the color-changing portion comprises a base layer, a color ink layer and an opaque layer arranged in sequence; the excitation portion comprises a solvent layer and a covering layer arranged in sequence; the solvent layer is attached to a side of the opaque layer away from the color ink layer; when the temperature-sensitive warning indicator is above a set indication temperature range, a phase-changing solvent of the solvent layer changes from solid to liquid, and enters the color ink layer through the opaque layer, so that at least part of the color of the color ink layer migrates to the side of the opaque layer away from the color ink layer.

[0007] A method for preparing a temperature-sensitive warning indicator, using a secondary molding method or a primary molding method;

[0008] The secondary molding method is to mold the color changing part and the excitation part separately. There is no special requirement for the ambient temperature during molding. Specifically, it includes:

[0009] S1: Making the color-changing part: printing a color ink layer and an opaque layer on the base layer in sequence;

[0010] S2: Make the excitation section:

[0011] A solvent layer with an open receiving cavity is formed on the easy-to-peel layer by die-cutting, laminating, ink printing, and glue coating, and then the open receiving cavity is filled with a phase change solvent, a phase change solvent microcapsule, or a porous material / microfiber material that has absorbed a phase change solvent, and finally a covering layer is applied on the side of the solvent layer away from the easy-to-peel layer to seal the open receiving cavity;

[0012] Alternatively, an open receiving cavity is formed on the cover layer by die-cutting, laminating, stamping, or laser ablation, and then the open receiving cavity is filled with a phase change solvent, a phase change solvent microcapsule, or a porous material / microfiber material that has absorbed a phase change solvent, and finally an easy-to-remove layer is covered on the side of the solvent layer away from the cover layer to seal the open receiving cavity;

[0013] S3: When in use, place the excitation part and the color changing part below the phase change point temperature, remove the easy-to-remove layer of the excitation part, and stick it on the color changing part;

[0014] The one-step molding method is to integrally mold the color changing part and the excitation part, specifically including:

[0015] In an environment below the phase change point, a color ink layer, an opaque layer, a solvent layer and a covering layer are sequentially arranged on the base layer by printing, gluing or laminating, and the layer must be placed in an environment below the phase change point before and during use;

[0016] Alternatively, in an environment above the phase change point, a color ink layer, an opaque layer, a microcapsule solvent layer and a covering layer are sequentially arranged on the base layer by printing, gluing or laminating. When in use, the microcapsules are activated at a temperature below the phase change point.

[0017] Compared with the prior art, the advantages of the present invention are: the solvent material is solid and non-fluid when it is below the phase transition point, and is liquid when it is above the phase transition point, and has solubility in specific coatings / inks; at a temperature below the phase transition point, it is a layer structure or a non-contact spaced structure, and will not show obvious changes; at a temperature above the phase transition point, it is fluid and soluble, forming micropores and capillary channels, and the solvent penetrates from the surface of the opaque layer. Under the action of the solvent, most or even all of the small molecular ink of the color ink layer migrates from the original bottom layer to the opaque surface layer, showing a color migration-color bleeding effect, that is, showing a different color / form from the original. Using this characteristic, it is possible to detect and record whether the indicator is exposed to a temperature above the phase transition point. In addition, the selection range of color ink and opaque layer is very wide, which can enrich the selection range of colors and graphics. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The structure of the temperature sensing warning indicator of the present invention is shown in FIG. Figure 1 .

[0019] Figure 2 The structure of the temperature sensing warning indicator of the present invention is shown in FIG. Figure 2 .

[0020] Figure 3 The structure of the temperature sensing warning indicator of the present invention is shown in FIG. Figure 3 .

[0021] Figure 4 Schematic diagram of the temperature-sensitive warning indicator prepared by the secondary molding method in Example 1 of the present invention before and after use.

[0022] Figure 5 Schematic diagram of the temperature-sensitive warning indicator prepared by the secondary molding method in Example 2 of the present invention before and after use.

[0023] Figure 6 Schematic diagram of the temperature-sensing warning indicator prepared by the secondary molding method in Example 3 of the present invention before and after use.

[0024] Figure 7 Schematic diagram of the temperature-sensing warning indicator prepared by the secondary molding method according to Example 4 of the present invention before and after use.

[0025] Figure 8 Schematic diagram of the temperature-sensitive warning indicator prepared by the secondary molding method in Example 5 of the present invention before and after use.

[0026] Fig. 9 Schematic diagram of the temperature sensing warning indicator prepared by the secondary molding method in Example 6 of the present invention before and after use.

[0027] Fig.10 Schematic diagram of the temperature-sensitive warning indicator prepared by the secondary molding method in Example 7 of the present invention before and after use.

[0028] Fig.11 It is a schematic diagram before and after use of the temperature-sensitive warning indicator prepared by a one-step molding method according to Example 8 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and beneficial effects of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] In the description of the present invention, it should be understood that the terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] like Figures 1 to 3 As shown, a temperature sensing warning indicator includes a color changing portion A and an excitation portion B, which are partially or entirely overlapped and stacked.

[0032] The color changing part A comprises a base layer 1, a color ink layer 2 and an opaque layer 3 arranged in sequence. In order to adjust the color developing sensitivity, a buffer layer 6 can be arranged on the side of the opaque layer 3 away from the color ink layer 2. Figure 1 and Figure 3 As shown, the buffer layer 6 can also be arranged between the color ink layer 2 and the opaque layer 3, as shown in FIG. Figure 2 The exciting part B comprises a solvent layer 4 and a covering layer 5 which are arranged in sequence, and the solvent layer 4 of the exciting part B is in contact with the buffer layer 6 or the opaque layer 3 of the color changing part A.

[0033] The ink layer 2 can be text, pattern or color block, and is made of organic small molecules: dyes, pigments, nano-color pastes, or small particle pigments. Including but not limited to: natural dyes, synthetic dyes: such as azo dyes, anthraquinone dyes, aromatic methane dyes, indigo dyes, sulfur dyes, phthalocyanine dyes, quinone imine dyes, quinoline dyes, cyanine dyes, nitroso dyes, nitro dyes, hydroxy copper dyes, actinium dyes, methine and polymethine dyes, diphenylethylene dyes and various heterocyclic dyes. Various animal and plant source pigments: cochineal red, lac red, phycocyanin, fish scale foil, hematoxylin pigment, shrimp shell pigment, lobster red pigment, crab shell pigment, phycocyanin, rosaria blue pigment, laver pigment. Carotenoids, flavonoid compounds, polyphenol compounds, polyphenol compounds, chlorophyll, alkaloid compounds, diketone compounds, indole compounds, carotene compounds, microbial fermentation pigments, microbial fermentation pigments. Nano-color paste with a particle size of less than 125nm, etc. The molecular weight of the organic small molecule is less than 1500, preferably less than 800.

[0034] The opaque layer 3 is made of a porous layer structure made of metal pigments, metal-medium composite pigments, pearlescent, opaque porous materials, opaque microporous membranes, mica and opaque pigments, and preferably has a transparency of 0-50%. The buffer layer 6 is made of porous materials, including aluminum oxide, silicon oxide, aerogel, corn cob, activated carbon, nanotubes, chromatography silicon, microfibers, microsponge, microlatex, etc.

[0035] The solvent layer 4 has at least one open receiving cavity, and the phase change solvent is filled in the open receiving cavity in the form of liquid core, microcapsule, porous medium adsorption or microfiber adsorption to form a phase change solvent zone. The open receiving cavity can be formed by die cutting, lamination, ink printing, glue coating, mechanical (or high temperature) stamping, laser ablation and other methods.

[0036] The materials of the phase change solvent can be esters, alkanes, alcohols, acids, ketones, including but not limited to: amyl formate, ethyl formate, butyl formate, butyl acetate, ethyl acetate, vinyl acetate, banana water, propyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, ethyl cinnamate, cyclohexyl acetate, hexyl acetate, benzyl benzoate, methyl laurate, ethyl laurate, propyl laurate, propyl laurate, isopropyl myristate, methyl cinnamate, triphenyl phosphite, dimethyl adipate, dimethyl carbonate, diethyl sebacate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diallyl phthalate, isopropyl palmitate, ethyl palmitate, methyl palmitate, isobornyl acetate, diethyl fumarate, glyceryl triacetate; isopropyl alcohol, butanol, amyl alcohol, 2-hexane Alcohol, nonanol, n-nonanol, n-decanol, 2-methyl-2-butanol, 1,4-butanediol, glycerol, n-dodecyl alcohol; 2-decanone, acetophenone, 2-undecanone, diacetyl, ambroxanone, coumarin, 4-tert-butylacetophenone, 1,3-dimethyl-2-imidazolidinone, 3-acetylpyridine, 2-acetylpyridine, m-nitrotoluene, methyl nonyl ketone, 2,3-heptanedione, 1-acetylnaphthalene, 2-isopropyl Naphthalene, 1-tetralone, 4-acetylpyridine, diphenylmethane, cyclohexane, phenylcyclohexane, p-xylene, diphenylmethane, dodecane, tridecane, tetradecane, pentadecane, hexadecane hexadecene, n-heptadecene, liquid paraffin, docosahexaenoic acid, arachidonic acid, acetic acid, propionic acid, butyric acid, valeric acid, a-linolenic acid, oleic acid, linoleic acid, ricinoleic acid, n-octanoic acid, n-heptanoic acid, nonanoic acid, or one or more thereof. The phase change point temperature range of the phase change solvent is preferably between -90°C and 20°C.

[0037] The base layer 1 and the cover layer 5 can be made of transparent or translucent ink layers or PET, BOPP, PP, OPP, PE, PVC, PVA, EVA, PA, PS, PU, ​​film, paper, etc.

[0038] In the temperature sensing warning indicator of the present application, the color changing part A and the exciting part B can adopt a split structure. In this structure, it is preferred to set an easy-to-remove layer 9 on the side of the solvent layer 4 away from the cover layer 5 (see Figure 4) to seal the open receiving cavity. Of course, if it is manufactured and transported below the phase change temperature, the easy-to-remove layer 9 may not be provided. When in use, the color-changing part A and the excitation part B are placed below the phase change temperature, the easy-to-remove layer 9 of the excitation part B is removed, and the activation is completed by attaching it to the color-changing part A. If the phase change solvent is in the form of microcapsules, external force is also required to break the microcapsules for activation.

[0039] The color changing part A and the excitation part B may also adopt an integrated structure. In this structure, the open receiving cavity of the solvent layer 4 will be closed by the buffer layer 6 or the opaque layer 3, so it can be used directly. This integrated structure needs to be manufactured and used at the phase change point of the solvent. If the phase change solvent adopts a microcapsule structure, there is no special temperature requirement for the manufacturing process, but external force needs to be applied to break the microcapsule for activation when used.

[0040] The temperature-sensitive warning indicator of the present application has a color ink layer 2 and a solvent layer 4 arranged in layers, and an opaque layer 3 is arranged in the middle. When the ambient temperature is lower than the melting point of the phase change material, it is solid, and the color of the color ink layer 2 will not migrate significantly. When the ambient temperature is higher than the melting point of the phase change material, it is liquid, and the solvent penetrates from the surface of the opaque layer 3. Under the action of the solvent, most or even all of the color of the color ink layer 2 migrates from the original bottom layer to the opaque surface layer, and a significant migration and color bleeding effect occurs, which is manifested as the color or pattern on both sides of the opaque layer changes. In addition, by setting a buffer layer 6, the temperature stress sensitivity is controllable, the color change is obvious, the color pattern selection is rich, and the color change principle is significantly different, and the cost is low. The specific change mode may include the following three display situations:

[0041] Case 1, such as Figure 1 As shown, an adhesive layer 7 and a release film 8 are provided on the base layer 1 of the color-changing portion A. When the release film 8 is torn off and the temperature-sensitive warning indicator is pasted on the product of the required temperature monitoring, the opaque layer 3 faces outward. When the temperature is lower than the phase change point, the color ink layer 2 is invisible due to the shielding effect of the opaque layer 3. When the temperature is higher than the phase change point, the phase change solvent in the solvent layer 4 melts and flows to the color ink layer 2 through the micropores of the buffer layer 6 and the opaque layer 3. Under the action of the liquid phase change solvent, the dye or small molecule pigment of the color ink layer 2 passes through the opaque layer 3 and migrates to the outward surface of the opaque layer 3. Macroscopically, it is manifested as the color of the color ink layer 2 migrating to the surface of the opaque layer 3, that is, the surface of the opaque layer 3 shows a significant color or pattern change. In this case, it can be manifested as the color or pattern of the color ink layer 2 displayed on the surface of the opaque layer 3, or it can be manifested as the color superposition on the surface of the opaque layer 3 to form a new color or pattern, or the original color and pattern on the surface of the opaque layer 3 disappear.

[0042] Case 2, such as Figure 2As shown, an adhesive layer 7 and a release film 8 are provided on the covering layer 5 of the excitation part B. When the release film 8 is torn off and the temperature-sensitive warning indicator is pasted on the product whose temperature needs to be monitored, the color ink layer 2 faces outward. When the temperature is lower than the phase change point, the color or pattern on the color ink layer 2 is clearly visible. When the temperature is higher than the phase change point, the phase change solvent in the solvent layer 4 melts, and the dye or small molecule pigment of the color ink layer 2 migrates to the inward surface of the opaque layer 3 under the action of the liquid phase change solvent. Macroscopically, it is manifested as the color of the color ink layer 2 migrating into the opaque layer 3. Due to the shielding effect of the opaque layer 3, the color or pattern visible to the naked eye disappears.

[0043] Case 3, if Figure 3 As shown, the temperature-sensing warning indicator is suspended to monitor the ambient temperature. Therefore, there is no need to set an adhesive layer 7 and a release film 8. The color ink layer 2 contains a migratable pigment and a non-migratable pigment, and its color is the superposition of the two pigments, or the set of the two pigments. When the temperature is higher than the phase change point, the migratable pigment of the color ink layer 2 migrates to the other side of the opaque layer 3 (i.e., the phase change material side), so that significant color or pattern changes can be seen on both sides of the opaque layer 3.

[0044] The preparation and use of the temperature sensing warning indicator of the present application are further described below through specific examples.

[0045] Example 1

[0046] like Figure 4 As shown, its basic structure is: film material / red dye layer / aluminum pigment layer / silicon dioxide buffer layer / self-adhesive film cut into cavities and solvent core layer / self-adhesive film surface material.

[0047] Production steps:

[0048] Production of color changing part A:

[0049] Step 1: Select a thin film material (base layer 1), such as 50um transparent PA.

[0050] Step 2: Apply a red dye layer (ink layer 2), an aluminum pigment layer (opaque layer 3), and a silicon dioxide buffer layer (buffer layer 6) in sequence; the red dye layer is the text "invalid".

[0051] Step 3: Die-cut and set aside.

[0052] Production of Excitation Part B:

[0053] In the first step, a release layer is coated or printed on the film substrate (easy-to-peel layer 9), or a part of the release layer is hollowed out (the hollowed-out area is similar in size and position to the solvent containing cavity). Optionally, a half-cut is made on the release layer near the solvent containing cavity so that the adhesive in the subsequent process flows into the release layer, which facilitates the subsequent process to better lock the solvent in the cavity.

[0054] In the second step, the adhesive film surface material is cut into holes, the waste is discharged, and then it is laminated with the film base material with the release layer prepared in the first step to form a solvent receiving cavity;

[0055] The third step is to select dimethyl adipate (DMA) with a melting point of 8° C. as a solvent material, and fill the DMA solvent material into the cavity by coating or positioning printing to form a solvent layer 4;

[0056] The fourth step is to laminate the film surface material with self-adhesive tape (covering layer 5) onto the solvent layer 4 with cavity in the third step to lock the DMA.

[0057] When in use, in a low temperature environment (at the phase change point temperature), peel off the film substrate of the excitation part B and stick it to the surface of the color changing part A to complete the activation, and place it near the product whose temperature needs to be monitored. In this embodiment, the excitation part B and the color changing part A are pasted together to start the activation, and the release film 8 at the bottom of the color changing part A can be torn off and stuck on the product whose temperature needs to be monitored. When the temperature is higher than the phase change point, the red "failure" on the back migrates to the silver on the front, so the silver on the front appears red "failure".

[0058] Example 2

[0059] like Figure 5 As shown, its basic structure is: film material / red-green-blue dye layer / aluminum pigment layer / aluminum oxide buffer layer / self-adhesive-heat-sealing film cut into cavities and solvent core layer / heat-sealing covering layer.

[0060] Production steps:

[0061] Preparation of the color-changing portion A: The steps are the same as those in Example 1, wherein the color ink layer 2 is a black layer composed of red-green-blue dye layers, and the opaque layer 3 is printed with a "√" symbol using blue dye after printing the aluminum pigment layer.

[0062] Production of Excitation Part B:

[0063] In the first step, a release layer is coated or printed on the film substrate (easy-to-peel layer 9), or a part of the release layer is hollowed out (the hollowed-out area is similar in size and position to the solvent containing cavity). Furthermore, it is possible to consider cutting half of the release layer near the solvent containing cavity so that the adhesive in the subsequent process flows into the release layer, which facilitates the subsequent process to better lock the solvent in the cavity.

[0064] In the second step, holes are cut in the heat-sealed film surface material with adhesive, waste is discharged, and then laminated with the film base material with release layer to form a solvent receiving cavity;

[0065] The third step is to select diallyl phthalate with a melting point of -70°C as a solvent material, and fill the cavity with the diallyl phthalate solvent material by coating or positioning printing to form a solvent layer 4;

[0066] The fourth step is to heat-seal and laminate the heat-seal film surface material (covering layer 5) onto the solvent layer 4 with cavity in the third step to lock the diallyl phthalate.

[0067] The method of use is the same as in Example 1. When the temperature is higher than the phase transition point, the red, green and blue dyes on the back migrate to the aluminum pigment, and the blue “√” on the surface of the opaque layer 3 disappears.

[0068] Example 3

[0069] like Figure 6 As shown, its basic structure is: film material / blue nano pigment layer / pearlescent pigment layer / corn cob silicon buffer layer / self-adhesive film cut into cavities and solvent core layer / self-adhesive film surface material.

[0070] Production steps:

[0071] Production of color changing part A:

[0072] Step 1: Select the film material (base layer 1), such as 50um PET;

[0073] Step 2: Apply a blue nano pigment layer (color ink layer 2), a pearlescent pigment layer (opaque layer 3), and a corncob buffer layer (buffer layer 6) in sequence;

[0074] Step 3: Die-cut and set aside.

[0075] Production of Excitation Part B:

[0076] The first step is to cut holes in the adhesive film surface material to remove waste and then laminate it on the film base material (easy-to-peel layer 9) to form a solvent receiving cavity;

[0077] Step 2: using diacetyl with a melting point of -3 to -4°C as a solvent material, and filling the diacetyl solvent material into the cavity by coating or positioning printing to form a solvent layer 4;

[0078] In the third step, the self-adhesive film surface material (covering layer 5) is laminated onto the solvent layer 4 with cavity in the second step to lock diacetyl.

[0079] The method of use is the same as in Example 1, and the adhesive in the structure is mostly an adhesive with a function of repeated sticking.

[0080] Example 4

[0081] like Figure 7As shown, its basic structure is: film material / red dye layer / optically variable pigment layer / microfiber buffer layer / self-adhesive-n-heptanoic acid mixed layer / film surface material.

[0082] Production steps:

[0083] Production of the color changing part:

[0084] Step 1: Select the film material (base layer 1), such as 50um PP;

[0085] Step 2: Apply a red dye layer (color ink layer 2), a light-variable pigment layer (opaque layer 3), and a microfiber buffer layer (buffer layer 6) in sequence;

[0086] Step 3: Die-cut and set aside.

[0087] Production of Excitation Part B:

[0088] Heptanoic acid with a melting point of -7.5°C is selected as the solvent material, and heptanoic acid is coated on the film substrate (easy-to-peel layer 9) and then composited with the film surface material with self-adhesive tape (covering layer 5); or heptanoic acid is directly mixed into the self-adhesive tape and then laminated with the film substrate.

[0089] The method of use is the same as in Example 1, and the optically variable pigment layer has an anti-counterfeiting function.

[0090] Example 5

[0091] like Figure 8 As shown, its basic structure is: film material / red dye layer / titanium dioxide pigment layer / carbon nanotube buffer layer / self-adhesive-film cut into cavities and solvent core layer / ink covering layer.

[0092] Production steps:

[0093] Preparation of color changing part: same as Example 1

[0094] Production of the Excitation Department:

[0095] In the first step, a release layer is coated or printed on the film substrate (easy-to-peel layer 9), or a part of the release layer is hollowed out (the hollowed-out area is similar in size and position to the solvent containing cavity). Furthermore, it is possible to consider cutting half of the release layer near the solvent containing cavity so that the adhesive in the subsequent process flows into the release layer, which facilitates the subsequent process to better lock the solvent in the cavity.

[0096] In the second step, holes are cut in the adhesive film surface material, waste is discharged, and then the film substrate with the release layer produced in the first step is laminated to form a solvent receiving cavity;

[0097] The third step is to fill the phenylcyclohexane solvent material into the cavity by coating or positioning printing to form a solvent layer 4;

[0098] Step 4: Cover the solvent layer 4 with the cavity in step 3 by UV ink by transfer printing or other methods to lock the phenylcyclohexane and form a covering layer 5.

[0099] The method of use is the same as in Example 1.

[0100] Example 6

[0101] like Fig. 9 As shown, its basic structure is: film material / red dye layer / aluminum pigment layer / micro latex buffer layer / solvent core layer / self-adhesive film surface material punched into convex cavity.

[0102] Production steps:

[0103] Preparation of color changing part: same as Example 1

[0104] Production of the Excitation Department:

[0105] In the first step, the self-adhesive film surface material (covering layer 5) is punched to form a three-dimensional surface (solvent containing cavity), dimethyl carbonate is directional-printed and coated in the cavity, and laminated with the film substrate (easy-to-remove layer 9) to lock the dimethyl carbonate. The film substrate may have a release layer, but it is not necessary.

[0106] The method of use is as in Example 1

[0107] Example 7

[0108] like Fig.10 As shown, the structure is the same as that of Example 6, wherein the micro latex buffer layer is changed to a buffer layer with diffusion effect: the fiber paper layer, the solvent cavity and the color ink layer are staggered. The solvent diffuses from the near end to the far end, and according to the diffusion distance, the time and amplitude of overheating can also be inferred. The farther it diffuses, the longer the overheating time or the greater the amplitude of overheating, and the degree of influence can be estimated.

[0109] Example 8

[0110] like Fig.11 As shown, the color changing part A and the excitation part B are designed in an integrated manner: a base layer 1, a color ink layer 2, an opaque aluminum pigment layer 3, a buffer layer 6, a solvent layer 4, and a covering layer 5 are printed or laminated in sequence. The solvent material is coated into a pressure-sensitive microcapsule to make a printable ink, which is coated or printed to form a central solvent layer 4.

[0111] When in use, the above-mentioned integrated material is placed near the product whose temperature needs to be monitored in a low temperature environment (at the phase transition point temperature). In this embodiment, the release film 8 at the bottom of the color-changing portion A can be torn off and attached to the product whose temperature needs to be monitored, and activation is completed below the phase transition point temperature by pressure or other means. In addition, a layer of scratching silver is printed on the surface of the covering layer, and pressure is applied to scrape off the scratching silver when in use to prove that the microcapsules have been activated.

[0112] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a temperature-sensitive warning indicator, characterized in that: Adopting secondary molding method; The secondary molding method is to mold the color changing part and the excitation part separately. There is no special requirement for the ambient temperature during molding. Specifically, it includes: S1: Making the color-changing part: printing a color ink layer and an opaque layer on the base layer in sequence; S2: Make the excitation section: A solvent layer with an open receiving cavity is formed on the easy-to-peel layer by die-cutting, laminating, ink printing, and glue coating, and then the open receiving cavity is filled with a phase change solvent, a phase change solvent microcapsule, or a porous material / microfiber material that has absorbed a phase change solvent, and finally a covering layer is applied on the side of the solvent layer away from the easy-to-peel layer to seal the open receiving cavity; Alternatively, an open receiving cavity is formed on the cover layer by die-cutting, laminating, stamping, or laser ablation, and then the open receiving cavity is filled with a phase change solvent, a phase change solvent microcapsule, or a porous material / microfiber material that has absorbed a phase change solvent, and finally an easy-to-remove layer is covered on the side of the solvent layer away from the cover layer to seal the open receiving cavity; S3: When in use, place the excitation part and the color-changing part below the phase change point temperature, remove the easy-to-peel layer of the excitation part, and stick it on the color-changing part.

2. A temperature-sensing warning indicator, obtained by the method for preparing a temperature-sensing warning indicator according to claim 1, characterized in that: It includes a color changing part and an excitation part; the color changing part includes a base layer, a color ink layer and an opaque layer arranged in sequence; the excitation part includes a solvent layer and a covering layer arranged in sequence; the solvent layer is attached to the side of the opaque layer away from the color ink layer; when the temperature-sensitive warning indicator is above the set indication temperature range, the phase change solvent of the solvent layer changes from solid to liquid, enters the color ink layer through the opaque layer, so that at least part of the color of the color ink layer migrates to the side of the opaque layer away from the color ink layer.

3. A temperature sensing warning indicator according to claim 2, characterized in that: The ink layer is mainly composed of dyes, pigments, nano-color pastes or small-particle pigments with molecular weights less than 1500, and has a text, pattern or color block layer structure.

4. A temperature sensing warning indicator according to claim 2, characterized in that: The opaque layer is mainly composed of a layer structure made of metal pigments, metal-medium composite pigments, pearlescent, opaque porous materials, opaque microporous films, mica and opaque pigments, and has a transparency of 0-50%.

5. A temperature sensing warning indicator according to claim 2, characterized in that: The solvent layer is provided with at least one open receiving cavity, and the phase change solvent is filled in the open receiving cavity in the state of liquid core, microcapsule, porous medium adsorption or microfiber adsorption.

6. A temperature sensing warning indicator according to claim 5, characterized in that: The phase change point temperature range of the phase change solvent is -30°C to 20°C.

7. A temperature sensing warning indicator according to claim 5, characterized in that: The color changing part and the exciting part are of separate structures, and an easy-to-remove layer for sealing the open accommodating cavity is arranged on the side of the solvent layer away from the covering layer.

8. The temperature sensing warning indicator according to claim 5, characterized in that: The open receiving cavity is made by die-cutting, laminating, ink printing, glue coating, mechanical stamping or laser ablation.

9. A temperature sensing warning indicator according to claim 2, characterized in that: The color changing part also includes a buffer layer made of porous material, which is arranged between the opaque layer and the color ink layer, or arranged on the side of the opaque layer away from the color ink layer.

10. A temperature sensing warning indicator according to claim 2, characterized in that: The side of the base layer facing away from the color ink layer, or the side of the cover layer facing away from the solvent layer, is provided with an adhesive layer and a release film in sequence.

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