CN104777162B

CN104777162B - Discoloration instruction device

Info

Publication number: CN104777162B
Application number: CN201510187130.5A
Authority: CN
Inventors: 刘永生; 郭欣; 刘文恒; 曾海明; 周世兵; 赵润生; 吴方奇; 覃玲; 魏彪
Original assignee: Shenzhen Nine Stars Printing and Packaging Group Co Ltd
Current assignee: Shenzhen Nine Stars Printing and Packaging Group Co Ltd
Priority date: 2015-04-17
Filing date: 2015-04-17
Publication date: 2018-02-09
Anticipated expiration: 2035-04-17
Also published as: CN104777162A

Abstract

The invention discloses a kind of discoloration instruction device, the discoloration instruction device includes basalis and the marker on the basalis, and the marker includes indicating section and reference section, and the reference section has at least two colors fixed；The indicating section can show different colors from carbon dioxide, ammonia or oxygen reaction and with the increase of reaction duration；The reference section is used to compare the color of the indicating section and judge the reaction duration of the indicating section and carbon dioxide, ammonia or oxygen.The discoloration instruction device can judge the reaction duration of the indicating section and carbon dioxide, ammonia or oxygen by comparing the color of indicating section and the color of reference section, and then the freshness of the product using the discoloration instruction device is judged according to the reaction duration.

Description

Color change indicating device

Technical Field

The invention relates to the technical field of indicating equipment, in particular to a color change indicating device.

Background

Perishable products such as food, beverage, medicine, etc. are easily rotten and deteriorated in aerobic environment, and in order to reduce oxygen content in the package, vacuum packaging or modified atmosphere packaging is usually adopted, and the delivery date and shelf life are printed on the external package. To identify whether a product is spoiled, a consumer can confirm whether the product is spoiled by looking at the date of delivery and the shelf life. However, the shelf life of the product marked on the product package can be reached only on the premise that the sealing condition or the oxygen-free environment suitable for storing the product is changed, such as air leakage caused by opening the package or poor sealing property, the perishable products such as food and the like must be eaten or used within a short time, otherwise, the product will go bad, and the eating or using of the bad product will cause harm to human bodies.

In daily life, people usually cannot distinguish whether the sealing performance of a product package reaches the standard or not, and cannot accurately remember the specific opening time of the sealed package of a perishable product, and cannot accurately remember the package date of short-term stored products such as cooked food and the like. This may lead to two cases: firstly, people eat or use deteriorated products to cause harm to human bodies; secondly, people discard the product before the product goes bad, which causes a great deal of waste.

Although there is an intelligent pigment and a color-changing film in the prior art, which can change color by reacting with carbon dioxide, ammonia gas and oxygen, it can be used as a component detection reagent or an anti-counterfeit material. However, it cannot be used to indicate the freshness of the product.

Therefore, there is a need to develop an indicator for indicating the freshness of a product, which helps a consumer to identify the freshness of the product and prompt the consumer to use the product before the product is deteriorated, and which avoids the waste of resources caused by discarding the non-deteriorated product.

Disclosure of Invention

The invention mainly aims to provide a color change indicating device, and aims to solve the technical problem that the existing intelligent pigment and color change film cannot be used for indicating the freshness of products.

In order to achieve the above object, the present invention provides a color change indicating device, which comprises a substrate layer and an indicating layer disposed on the substrate layer, wherein the indicating layer comprises an indicating portion and a reference portion, and the reference portion has at least two fixed colors;

the indicator portion is capable of reacting with carbon dioxide, ammonia or oxygen and exhibits a different color as the length of the reaction increases;

the reference part is used for comparing the color of the indicating part to judge the reaction time of the indicating part and carbon dioxide, ammonia gas or oxygen.

Preferably, the color change indicator further comprises a transparent protective layer having a neutral PH and being gas permeable provided on the indicating portion, a first transparent adhesive layer being gas permeable provided on the transparent protective layer and the reference portion, and a first transparent barrier layer being gas permeable provided on the first transparent adhesive layer.

Preferably, the indicator portion is a carbon dioxide sensitive indicator material comprising a first PH sensitive dye and a phase transfer catalyst, the first PH sensitive dye being at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, cetyltrimethylammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, the phase transfer catalyst being at least one of a quaternary ammonium salt, sodium hydroxide and sodium bicarbonate.

Preferably, the color change indicating device further comprises a transparent release layer arranged on the first transparent barrier layer, a second transparent adhesive layer arranged on the transparent release layer in a peelable manner, and a second transparent barrier layer arranged on the second transparent adhesive layer.

Preferably, the indicating portion is an ammonia-sensitive indicating material comprising a second PH-sensitive dye that is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue, and m-cresol purple, and a volatile basic substance that is at least one of ammonium hydroxide, propylamine, n-butylamine, n-hexylamine, and n-octylamine; or,

the indicating part is an oxygen sensitive indicating material, the oxygen sensitive indicating material comprises an oxygen sensitive active dye, a photocatalyst material and an electron donor material, the oxygen sensitive active dye is at least one of thiazine dye, oxazine dye, azine dye and indophenol dye, the photocatalyst material is at least one of nano titanium dioxide, nano strontium titanate, nano tin oxide, nano tungsten oxide and nano zinc oxide, and the electron donor material is at least one of disodium ethylene diamine tetraacetate, triethanolamine, glucose, fructose, polyvinyl alcohol, polyhydric alcohol, trihydroxyhexane and citric acid.

Preferably, the color change indicating device further comprises a transparent release layer, and the transparent release layer is arranged between the reference part and the first transparent adhesive layer.

Preferably, the indicator portion is an ammonia-sensitive indicator material comprising a second PH-sensitive dye that is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue, and m-cresol purple.

Preferably, the color change indicating device further comprises a third adhesive layer arranged on the side of the substrate layer far away from the indicating layer and a peeling layer capable of being peeled from the side of the third adhesive layer far away from the substrate layer, and the third adhesive layer is used for bonding the color change indicating device peeled from the peeling layer to an article.

In addition, in order to achieve the above object, the present invention further provides a color change indicator, comprising a substrate layer, an indicating layer and a transparent protective layer which is permeable to air and has a neutral PH value, wherein the indicating layer is disposed on the substrate layer and comprises a reference portion and an indicating portion, and the transparent protective layer is disposed on the indicating portion;

the reference portion and the indicating portion are made of the same material;

the indicating part is used for reacting with carbon dioxide, ammonia gas or oxygen which penetrates through the transparent protective layer and presents different colors along with the increase of the reaction time;

the reference part is used for directly reacting with carbon dioxide, ammonia gas or oxygen to present an initial color and a final color, and the reference part is used for comparing the color of the indicating part to judge the reaction time of the indicating part with the carbon dioxide, the ammonia gas or the oxygen gas.

Preferably, the indicating portion comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicating material; the condition sensitive indicating material is a carbon dioxide sensitive indicating material, the carbon dioxide sensitive indicating material comprises a first PH value sensitive dye and a phase transfer catalyst, the first PH value sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, hexadecyl trimethyl ammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, and the phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate.

Preferably, the color change indicating device further comprises a transparent release layer arranged on the transparent protective layer and the reference part, a second transparent adhesive layer arranged on the transparent release layer in a peelable manner, and a second transparent barrier layer arranged on the second transparent adhesive layer.

Preferably, the indicating portion comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicating material; the condition sensitive indicating material is an oxygen sensitive indicating material, the oxygen sensitive indicating material comprises an oxygen sensitive active dye, a photocatalyst material and an electron donor material, the oxygen sensitive active dye is at least one of thiazine dye, oxazine dye, azine dye and indophenol dye, the photocatalyst material is at least one of nano titanium dioxide, nano strontium titanate, nano tin oxide, nano tungsten oxide and nano zinc oxide, and the electron donor material is at least one of disodium ethylene diamine tetraacetate, triethanolamine, glucose, fructose, polyvinyl alcohol, polyhydric alcohol, trihydroxyhexane and citric acid.

In addition, in order to achieve the above object, the present invention further provides a color change indicator, which includes a reference layer, a transparent substrate layer disposed on the reference layer, an indicating layer disposed on the substrate layer, a first transparent adhesive layer disposed on the indicating layer and being permeable to air, and a first transparent barrier layer disposed on the first transparent adhesive layer and being permeable to air, wherein the reference layer has at least two fixed colors and a first hollow portion is disposed on the reference layer;

the indicating layer is used for reacting with carbon dioxide, oxygen or ammonia gas and presents different colors along with the increase of the reaction time;

the reference layer is used for comparing the color of the indicating layer to judge the reaction time of the indicating layer and carbon dioxide, ammonia gas or oxygen.

Preferably, the color change indicating device further comprises a covering layer arranged between the reference layer and the substrate layer, and a second hollow portion corresponding to the first hollow portion is arranged on the covering layer.

Preferably, the indicator layer comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicator material; the condition sensitive indicating material is a carbon dioxide sensitive indicating material which comprises a first PH value sensitive dye and a phase transfer catalyst, wherein the first PH value sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, hexadecyl trimethyl ammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, and the phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate;

the color change indicating device further comprises a third adhesive layer and a stripping layer, wherein the third adhesive layer is arranged on one side, far away from the base layer, of the reference layer, the stripping layer is arranged on one side, far away from the reference layer, of the third adhesive layer in a stripping mode, and the third adhesive layer is used for bonding the color change indicating device stripped from the stripping layer to an article.

The indicating part of the color change indicating device can react with carbon dioxide, oxygen or ammonia gas and presents different colors along with the increase of the reaction time, the reaction time of the indicating part and the carbon dioxide, the ammonia gas or the oxygen gas is judged by comparing the color of the reference part with the color of the indicating part according to the color of the reference part, and then the freshness of a product applying the color change indicating device is judged according to the reaction time.

Drawings

FIG. 1 is a schematic structural diagram of a color change indicator according to a first preferred embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a color change indicator according to a second preferred embodiment and a third preferred embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a color change indicator according to a fourth preferred embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a color change indicator according to a fifth preferred embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a color change indicator according to a sixth preferred embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a color change indicator according to a seventh preferred embodiment of the present invention;

fig. 7a to 7h are schematic views illustrating a manufacturing process of a color change indicator according to a preferred embodiment of the present invention.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The present invention provides a color change indicating device, referring to fig. 1, fig. 1 is a schematic structural diagram of a first preferred embodiment of the color change indicating device of the present invention; in the first preferred embodiment, the color change indicating device comprises a substrate layer 24 and an indicating layer 26 disposed on the substrate layer 24, the indicating layer 26 comprising an indicating portion 260 and a reference portion 262, the reference portion 262 having at least two fixed colors. The indicator portion is capable of reacting with carbon dioxide, ammonia or oxygen and exhibits a different color as the length of the reaction increases; the reference part is used for comparing the color of the indicating part to judge the reaction time of the indicating part and carbon dioxide, ammonia gas or oxygen.

In the first preferred embodiment, the color change indicator further comprises a transparent protective layer 27 having a neutral pH and being gas-permeable and disposed on the indicator portion 260, a first transparent adhesive layer 28 disposed on the transparent protective layer 27 and the reference portion 262 and being gas-permeable, and a first transparent barrier layer 29 disposed on the first transparent adhesive layer 28 and being gas-permeable.

In the first preferred embodiment, further, the color change indicator further comprises a coating layer (not shown) disposed on the first transparent barrier layer 29; the color change indicator further comprises a third adhesive layer 22 arranged on one side of the substrate layer 24 far away from the indicating layer 26 and a release layer 20 capable of being peeled from one side of the third adhesive layer 22 far away from the substrate layer 24, wherein the third adhesive layer 22 is used for bonding the color change indicator peeled from the release layer 20 to an article, such as product packaging.

In the first preferred embodiment, and still further, the substrate layer 24 acts as a substrate for the indicator layer 26, having transparency and good air-tightness. The material of the optional substrate layer 24 is aluminum oxide foil, high density polyethylene, polypropylene, polyethylene terephthalate, or polyethylene terephthalate. It should be understood that similar materials with better transparency and air tightness can be used as the base layer material of the present invention. The substrate layer 24 is preferably polyethylene terephthalate.

The indication layer 26 is divided into an indication portion 260 and a reference portion 262, wherein the indication portion 260 can be located at the center of the reference portion 262 or at the periphery of the reference portion 262, and preferably, the indication portion 260 is located at the center of the reference portion 262 and is arranged in a circle. The indicating portion 260 is a condition-sensitive material, which can be printed by oxygen-sensitive ink, carbon dioxide-sensitive ink or ammonia-sensitive ink, but is not limited to the form of ink, and the condition-sensitive material gradually changes color from an initial color to a final color after being excited by a sensitive gas, and the degree of color change is in a linear relationship with the reaction duration. It should be understood that other types of condition sensitive materials may also be used as the indicator portion 260 of the present invention. Preferably, the indicator portion 262 is a carbon dioxide sensitive indicator material that can react with carbon dioxide to change color. Specifically, the carbon dioxide sensitive indicator material includes a first PH sensitive dye that is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, cetyltrimethylammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101, and thymol blue, and a phase transfer catalyst that is at least one of a quaternary ammonium salt, sodium hydroxide, and sodium bicarbonate, wherein the cetyltrimethylammonium cation may be generated from trimethylhexadecylammonium bromide or trimethylhexadecylammonium chloride. Further, the carbon dioxide sensitive indicating material also comprises a binder and a plasticizer, so as to enhance the film forming adhesiveness and flexibility of the indicating material and facilitate the formation of an interlayer structure, wherein the binder is at least one of polyvinyl butyral, nitrocotton, polyvinyl alcohol, hydroxyethyl cellulose and hydroxypropyl cellulose, and the plasticizer is at least one of glycerol, diisodecyl adipate, tributyl phosphate and dimethyl phthalate.

However, the first preferred embodiment utilizes the reverse reaction between the indicating part and carbon dioxide as the comparison basis, and the indicating part shows different colors as the duration of the reverse reaction increases. Specifically, the color of the indicating part after the indicating part and the carbon dioxide are completely reacted is taken as an initial color, the carbon dioxide gradually seeps out of the indicating part along with the increase of the reaction time, the color of the indicating part when the carbon dioxide seeps out to the equilibrium state is taken as an end color, and obviously, other colors between the initial color and the end color can also be taken as reference colors.

The reference portion 262 is printed from a conventional ink having at least two fixed colors, each of which finds the same hue at a different color change stage of the indicator portion 260. Preferably, the reference portion 262 has three different colors and is annularly disposed around the indicator portion 260, i.e., the annular reference portion 262 includes equally divided first, second and third color cells. The color of the first color block corresponds to the initial color of the indicating portion 260 (the reaction duration is shortest), the color of the second color block corresponds to the middle color of the indicating portion 260 (the reaction duration is moderate), the color of the third color block corresponds to the end color of the indicating portion 260 (the reaction duration is longest), the initial color, the middle color and the end color respectively correspond to the three stages of freshness, non-deterioration and deterioration of the product, and then the consumer judges the freshness of the product by comparing the color of the reference portion 262 with the color of the indicating portion 260, as shown in fig. 7a to 7 h.

The PH value of the transparent protective layer 27 is neutral, which plays a role of isolating and protecting the indicating part 260, and prevents the PH sensitive component in the indicating part 260 from being negatively affected by the chemical component with acidic PH value in the first transparent adhesive layer 28, so that the color changing function is lost. The transparent protection layer 27 may be a transparent electrochemical aluminum material stamped on the indication part 260, a UV varnish printed on the first transparent adhesive layer 28 or a hollow-out treatment of the corresponding part of the first transparent adhesive layer 28, or a polymer with a neutral PH value coated on the indication part 260, and preferably, the transparent protection layer 27 is a transparent electrochemical aluminum material.

The first transparent adhesive layer 28 is positioned between the indicator layer 26 and the first transparent barrier layer 29 such that the first transparent barrier layer 29 is in intimate contact with the indicator layer 26. The first transparent adhesive layer may be an acrylate adhesive or a varnish coat adhesive. The first transparent barrier layer 29 can be designed to be peelable and non-peelable depending on the shelf life of the product; generally, for products with shorter shelf life, it is suitable to design as a peelable barrier; for products with a longer shelf life, it is suitable to design the barrier layer as a non-peelable layer. Preferably, the first transparent adhesive layer 28 is an acrylate.

The first transparent barrier layer 29 has semi-permeable sealing characteristics, allows and controls slow permeation or permeation of gas components, allows a material of the indicating portion to react with a sensitive gas to undergo a visible color change, and thus can adjust a color change period of the color change indicating device by controlling the material and thickness of the first transparent barrier layer. The optional first transparent barrier layer material is polyethylene terephthalate (PET), ethylene vinyl alcohol copolymer (EVOH), vinylidene chloride (PVDC), polyvinyl alcohol (PVA), Low Density Polyethylene (LDPE), Medium Density Polyethylene (MDPE), High Density Polyethylene (HDPE), polypropylene (PP), polyester, or polyethylene terephthalate. It should be understood that other transparent materials having semi-permeable sealing properties may be used as the first transparent barrier layer material of the present invention. Preferably, the first transparent barrier layer 29 is Low Density Polyethylene (LDPE).

The coating layer functions to prevent gas from permeating or oozing out, and is further used to adjust the color change cycle of the color change indicator. The material of the optional coating layer is polyethylene terephthalate, ethylene-vinyl alcohol, vinyl chloride, polyvinyl alcohol, an alumina coating or polyethylene terephthalate. In use, the coating layer may be retained or stripped depending on the length of the desired color change cycle. Preferably, the coating layer is ethylene vinyl acetate.

The third adhesive layer 22 is positioned between the release layer 20 and the substrate layer 24, and the third adhesive layer 22 may be attached to a product or product packaging after the release layer 20 is released. The material of the optional third adhesive layer 22 is an acrylate adhesive or a varnish-coat adhesive, it being understood that other types of adhesives may be used as the material of the third adhesive layer 22 of the present invention. Preferably, the third adhesive layer 22 is an acrylate, wherein the adhesion of the third adhesive layer 22 is less than the adhesion of the first transparent adhesive layer 28.

The release layer 20 protects the third adhesive layer 22, and the release layer 20 is non-adhesive and can be peeled from the third adhesive layer 22. Optional release layer 20 is release paper or a silicone polymer. Preferably, the release layer 20 is release paper.

The colour change indicator of the first preferred embodiment is a carbon dioxide sensitive colour change indicator suitable for use in MAP modified atmosphere packaging. When in use, a manufacturer attaches the color change indicating device with the stripping layer 20 stripped to the inner wall of the modified atmosphere package, loads the product and injects carbon dioxide gas, and enters a circulation link along with the product after sealing. In a high concentration carbon dioxide environment, carbon dioxide gas permeates into the indicator layer 26 through the first transparent barrier layer 29 to undergo a color change reaction with the carbon dioxide sensitive indicator material in the indicator portion 260, and the color of the indicator portion 260 finally forms a stable initial color during a logistics cycle when the product is in a fresh state.

When a consumer purchases a product, the color change indicating device can be checked through the transparent packaging bag, if the color of the indicating part 260 is in the initial color and is the same as the color of the first color block of the reference part 262, the sealing degree of the packaging bag is good, and the shelf life of the product is effective. When a consumer unpacks the package, the concentration of the carbon dioxide in the package is quickly restored to the normal level of the air, at the moment, the high-concentration carbon dioxide in the color change indicating device slowly seeps out through the first transparent isolation layer 29 to cause the color of the material of the indicating portion 260 to gradually change, when the concentration of the carbon dioxide inside and outside the color change indicating device reaches balance, the color of the indicating portion 260 changes to the end color (the color change period can be set by adjusting the material and the thickness of the first transparent isolation layer 29, and the color change period is the shelf life of the product after the package is opened), and the consumer can safely use the product within the period that the material of the indicating portion 260 changes the color to the end color.

When the consumer finds that the color of the indicating portion 260 is not the end color through the packaging bag, it indicates that the air tightness of the product packaging is poor and the indicated shelf life of the packaging bag is not effective. If the color of the indicator portion 260 is in another color between the starting color and the ending color, it indicates that the product is not fresh but still usable; if the indicator portion 260 is colored to the end point, it indicates that the product is spoiled and unusable.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a color change indicating device according to a second preferred embodiment and a third preferred embodiment of the present invention. The color change indicating device of the second preferred embodiment is different from the color change indicating device of the first preferred embodiment in that:

the color change indicator of the second preferred embodiment further includes a transparent release layer 40 disposed on the first transparent barrier layer 29, a second transparent adhesive layer 42 disposed on the transparent release layer 40 in a peelable manner, and a second transparent barrier layer 44 disposed on the second transparent adhesive layer 42.

The additional structure is mainly used for thoroughly blocking the permeation or seepage of sensitive gas, so that the color of the indicating part of the color change indicating device is always in the initial color.

The transparent release layer 40 may be silicone, fatty acid or polypropylene compound, and reduces the adhesive force between the second transparent adhesive layer 42 and the first transparent barrier layer 29 by locally printing a non-adhesive substance, which plays two roles: on the one hand, the adhesion between the second transparent adhesive layer 42 and the first transparent barrier layer 29 is larger than the adhesion between the third adhesive layer 22 and the release layer 20, so that when a customer transfers the color change indicator from the release layer 20 to a product package by a labeling machine, the color change indicator can be surely peeled from the release layer 20 with lower adhesion (not the transparent release layer 40 with higher adhesion); alternatively, the color change indicator means may be peeled away after it is attached to the product package. Preferably, the transparent release layer 40 is a silicone polymer.

The second transparent adhesive layer 42 is located between the transparent release layer 40 and the second transparent barrier layer 44, and may be an acrylate adhesive or a varnish-coating adhesive. Preferably, the second transparent adhesive layer 42 is an acrylate.

The second transparent barrier layer 44 is positioned on the top layer and has good air tightness to completely isolate the sensitive gas, so that the material of the indicating portion 260 inside the color change indicator does not react with the sensitive gas in a color change manner, and the material can be peeled off together with the second transparent adhesive layer 42, after peeling, the color change indicator is activated, and the sensitive gas starts to permeate or seep out of the first transparent barrier layer 29, thereby causing the color change of the indicating material. Preferably, the second transparent barrier layer 44 is polyethylene terephthalate.

The indicator portion 260 is preferably an ammonia-sensitive indicator material that includes a second PH-sensitive dye and a volatile alkaline material that is reduced-emission ammonia-sensitive indicator material because it can be volatilized from the indicator material. The second pH value sensitive dye is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue and m-cresol purple, and the volatile alkaline substance is at least one of ammonium hydroxide, propylamine, n-butylamine, n-hexylamine and n-octylamine. Further, the ammonia sensitive indicator material also comprises a binder and a plasticizer.

The transparent protective layer 27 is preferably a UV varnish that is printed and cured over the indicator portion 260 during the manufacturing process to protect against the adverse effects of PH sensitive components of the indicator material caused by the acidic PH chemical components of the first transparent adhesive layer 28.

And the first transparent barrier layer 29 is preferably High Density Polyethylene (HDPE).

The color change indicating device of the second preferred embodiment is a color change indicating device sensitive to decrement ammonia. When the color change indicator is used, a manufacturer attaches the color change indicator with the peeling layer 20 peeled off to the outer side of a product, the color change indicator is circulated along with the product entering the market, and after a consumer purchases the product, the second transparent barrier layer 44 is peeled off when the sealed package is opened, so that the color change indicator is started. At this time, the basic volatile substance slowly bleeds out through the first transparent barrier layer 29 to cause the PH of the indicating portion 260 to be lowered, thereby causing the second PH sensitive dye in the ammonia sensitive indicating material to be discolored, and the discoloration period can be adjusted by changing the material and thickness of the first transparent barrier layer 29, and can range from several minutes to several months. The color change period of the color change indicating device is the shelf life of the product after the sealed package is opened, and the product is safe for consumers to use in the color change period of the color change indicating device.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a color change indicating device according to a third preferred embodiment of the present invention, the color change indicating device of the third preferred embodiment has the same structure as the color change indicating device of the second preferred embodiment, and only the materials are different, specifically as follows:

the indicating portion 260 is preferably an oxygen sensitive indicating material, and specifically, the oxygen sensitive indicating material includes an oxygen sensitive reactive dye, a photocatalyst material, and an electron donor material. Further, the oxygen-sensitive reactive dye is at least one of thiazine dye, oxazine dye, azine dye and indophenol dye, the photocatalyst material is at least one of nano titanium dioxide, nano strontium titanate, nano tin oxide, nano tungsten oxide and nano zinc oxide, and the electron donor material is at least one of disodium ethylenediamine tetraacetate, triethanolamine, glucose, fructose, polyvinyl alcohol, polyhydric alcohol, trihydroxyhexane and citric acid. Still further, the oxygen sensitive indicator material further comprises a binder and a hydrophobic agent, preferably, the binder is at least one of gelatin, hydroxyethyl cellulose, polyvinyl butyral, ethyl cellulose, cellulose acetate, polyvinyl pyrrolidone, polyethylene oxide and polymethyl methacrylate, and the hydrophobic agent is sulfonated polystyrene.

The transparent protection layer 27 is preferably made of a transparent electrochemical aluminum material, and the transparent electrochemical aluminum material is thermoprinted above the indication part 260 in the production process to be used for isolation protection, so that the adverse effect of a chemical component with an acidic pH value in the first transparent adhesive layer 28 on a pH sensitive component in the indication material is avoided.

During printing, the oxygen-sensitive indicator material contains an oxygen-sensitive reactive dye in an oxidized state and has no oxygen-sensitive characteristic. After the color change indicating device is formed, the photocatalyst material is irradiated by UV light with the wavelength of 380nm, photo-generated electrons with reducibility and photo-generated holes with oxidability are generated after the photocatalyst material is excited by the UV light, the photo-generated electrons with reducibility can reduce the oxygen sensitive reactive dye in an oxidation state, and meanwhile, the photo-generated holes with oxidability are reduced by the electron donor material. After the oxygen sensitive reactive dye is activated, the oxygen sensitive reactive dye is in a reduction state and is easily oxidized by oxygen, the color is changed in the oxidation process, and the color change degree and the time form a functional relation.

In the third preferred embodiment of the color change indicator with oxygen sensitivity, when in use, the manufacturer attaches the color change indicator with the peel-off layer 20 removed to the outside of the packaging bag through the third transparent adhesive layer 22, and the color change indicator enters the market together with the product. Protected by the substrate layer 24, the first transparent barrier layer 29 and the second transparent barrier layer 44, oxygen components cannot enter the interior of the sealed color change indicator device, and the oxygen sensitive indicator dye is in a stable reduced state.

When the consumer purchases the product, the second transparent barrier layer 44 is peeled off when the sealed package is opened, at this time, oxygen can slowly permeate through the first transparent barrier layer 29, and undergoes redox reaction with the oxygen-sensitive indicator dye, so that the indicator portion 260 undergoes a slow color change and changes color from an initial color to a final color, and the color change period is the shelf life of the product after the sealed package is opened (the color change period can be set by adjusting the parameters of the material and thickness of the first transparent barrier layer 29, and can be from several minutes to several months). It is safe to use the product during the color change cycle of the color change indicator device.

The color change indicating device can also be used in oxygen-free modified atmosphere packaging. The manufacturer attaches the color change indicator to the interior of the modified atmosphere package through the third adhesive layer 22 after peeling off the peel layer 20, peels off the second transparent barrier layer 44, then loads the product and injects carbon dioxide gas, at this time, the label is in an oxygen-free environment, the color of the indicating part 260 of the color change indicator is in the initial color, and the color enters the market with the product.

When a consumer purchases a product, the color change indicating device can be checked through the transparent packaging bag, and if the color of the indicating part 260 is in the initial color, the sealing degree of the packaging bag is good, and the shelf life of the product is effective. When the consumer detaches the sealed package, oxygen begins to permeate into the first transparent barrier layer 29 and undergo a redox reaction with the oxygen sensitive indicator material, causing the indicator portion 260 to undergo a color change and eventually change color to a final color, which is safe for the consumer to use the product during the color change cycle of the color change indicator device.

When a consumer finds that the color of the indicator is not in the end point color through the packaging bag, the air tightness of the product packaging is poor, and the indicated shelf life of the packaging bag is invalid; if the color of the indicator portion 260 is in another color between the starting color and the ending color, it indicates that the product is not fresh but still usable; if the indicator color is at the end color, it indicates that the product is spoiled and unusable.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a color change indicating device according to a fourth preferred embodiment of the present invention; the color change indicating device of the fourth preferred embodiment is different from the color change indicating device of the first preferred embodiment in that:

the color change indicating device further comprises a transparent release layer 40, the transparent release layer 40 being located above the reference portion 262 and below the first transparent adhesive layer 28. Preferably, the transparent release layer 40 is a silicone polymer, which functions as a de-adhesive and release layer.

The base layer 24 is preferably a high density polyethylene material.

The indicating portion 260 of the indicator layer 26 is preferably an ammonia-sensitive indicating material, and specifically the ammonia-sensitive indicating material includes a second PH-sensitive dye that is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue, and m-cresol purple. Further, the ammonia sensitive indicating material also comprises a binder and a plasticizer, wherein the binder is at least one of polyvinyl butyral, nitrocotton, polyvinyl alcohol, hydroxyethyl cellulose and hydroxypropyl cellulose, and the plasticizer is at least one of glycerol, diisodecyl adipate, tributyl phosphate and dimethyl phthalate.

The ammonia-sensitive color change indicator of the fourth preferred embodiment is an incremental color change indicator, i.e., it changes color by reaction with ammonia gas, and is therefore suitable for use in sealed meat packaging. In use, the manufacturer attaches the color change indicator with the peel layer 20 removed directly to the meat product and peels the first transparent barrier layer 29 to increase the sensitivity of the color change indicator. After being sealed, the product enters the market to be circulated. When the protein in the meat is decomposed into volatile amine or ammonia gas after putrefaction, and the volatile amine or ammonia gas and the second pH value sensitive dye are subjected to color change reaction, the color change is larger along with the increase of the amine/ammonia concentration.

When the consumer purchases the product, the color change indicator can be viewed through the transparent package, and if the color of the indicator portion 260 is in the initial color, the product is not spoiled. If the color change indicating device indicates that the portion 260 has changed color, the product will have deteriorated to a greater extent the darker the color, and it should be noted that eating any of the spoiled meat products will be detrimental.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a color change indicating device according to a fifth preferred embodiment of the present invention; in the fifth preferred embodiment, the color change indicating device comprises a substrate layer 24 and an indicating layer 26 arranged on the substrate layer 24, wherein the indicating layer 26 comprises an indicating part 260 and a reference part 262 which are arranged in a splicing manner; the color change indicator further comprises a gas permeable transparent protective layer 27 disposed on the indicator portion 260.

Further, the reference portion 262 is identical to and integrally provided with the indicating portion 260.

Furthermore, the color change indicator further comprises a third adhesive layer 22 disposed on a side of the substrate layer 24 away from the indicator layer 26 and a release layer 20 releasably disposed on a side of the third adhesive layer 22 away from the substrate layer 24, wherein the third adhesive layer 22 is used for bonding the color change indicator to the product package.

Still further, the base layer 24 is preferably high density polyethylene.

The indicator layer 26 comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicator material; the condition sensitive indicator material is preferably a carbon dioxide sensitive indicator material, in particular, the carbon dioxide sensitive indicator material comprises a first PH sensitive dye and a phase transfer catalyst, the first PH sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresolphthalein, bromothymol blue, cresol red, cetyltrimethylammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, wherein the cetyltrimethylammonium cation may be generated from trimethylcetylammonium bromide or trimethylcetylammonium chloride. The phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate. Further, the optional thermoplastic polymer is polyethylene, polypropylene, polyethylene oxide, polycarbonate, polyether, polyester, polyamide, or polyoxymethylene. The inorganic pigment is hydrophobic inorganic pigment particles or hydrophilic inorganic pigment particles, and the optional hydrophobic inorganic pigment particles are at least one of titanium dioxide, silicon dioxide, aluminum oxide, cadmium red, cadmium yellow, Prussian blue, chrome yellow, carbon black and zinc white. It is to be understood that other inorganic pigments having specific hydrophobic characteristics may also be used as the hydrophobic inorganic pigment of the present invention. The hydrophilic inorganic pigment particles are at least one of silica, alumina, red iron oxide and yellow iron oxide. It is to be understood that other inorganic pigments having specific hydrophilic characteristics may also be used as the hydrophilic inorganic pigment of the present invention.

The inorganic pigment particles described above serve three functions: firstly, the micro-uneven surface has adsorbability and can adsorb active dye; second, different inorganic pigment particles have different affinities for water, and the selection of inorganic pigment particles that are consistent with the affinity of the thermoplastic polymer for water can improve the compatibility of the thermoplastic polymer and the inorganic pigment; and thirdly, the inorganic pigment has stable color, the color C can be obtained after the inorganic pigment of the color A and the reactive dye of the color B are mixed according to the principle of a pigment subtractive method, and the shade of the color C is closely related to the ratio of the pigment A to the dye B. Therefore, by adding at least one inorganic pigment with different proportions, the indicating portion 260 can realize colorful initial color effect and color change effect, thereby realizing the color diversification of the indicating portion 260. In addition, the inorganic pigment of the present invention has good thermal stability, does not decompose during the hot melting and extrusion of the thermoplastic polymer, and does not physically or chemically react with other components.

The transparent protective layer 27 is preferably transparent alumite or UV varnish.

The third adhesive layer 22 is preferably acrylic and the release layer 20 is preferably release paper.

In the carbon dioxide sensitive color change indicating device of the fifth preferred embodiment, when in use, a manufacturer attaches the color change indicating device with the peeling layer 20 removed in the modified atmosphere package, fills the product, injects carbon dioxide gas, and then seals the package, and the color change indicating device enters the market along with the product for circulation. During the time, the indicating layer 26 is color-changed with the carbon dioxide gas of high concentration in the packing bag, and finally the indicating part 260 and the reference part 262 are formed to have the same initial color.

When a consumer purchases a product, the color change indicating device can be checked through the transparent package, if the colors of the reference part 262 and the indicating part 260 are both in the initial color, the sealing degree of the package bag is good, and the shelf life of the product is effective, after the consumer unpacks the sealed package, the reference part 262 is not covered by the transparent protective layer 27, the carbon dioxide exudation speed is high, the color is changed to the end color in a short time to form the reference part 262, the indicating part 260 is covered by the transparent protective layer 27 in a blocking way, the carbon dioxide exudation speed is low, the color is changed to the end color in a long time, the color change period can be adjusted by adjusting the thickness of the transparent protective layer 27 or the composition of UV oil, the color change period of the indicating part 260 is the shelf life of the product after the sealed package is unpacked, and the product is safe.

If the consumer sees the reference portion 262 through the package as being in the finish color and the indicator portion 260 is between the initial and finish colors, the package is sealed poorly and the product is not fresh but still usable. If the consumer sees through the package that both the reference portion 262 and the indicator portion 260 change color to the end color, this indicates that the package is poorly sealed and that the product has deteriorated.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a color change indicating device according to a sixth preferred embodiment of the present invention; the color change indicating device of the sixth preferred embodiment is different from the color change indicating device of the fifth preferred embodiment in that:

the color change indicator of the sixth preferred embodiment further includes a transparent release layer 40 disposed on the transparent protection layer 27 and the reference portion 262, a second transparent adhesive layer 42 disposed on the transparent release layer 40 in a peelable manner, and a second transparent barrier layer 44 disposed on the second transparent adhesive layer 42. Further, the transparent release layer 40 is preferably a silicone polymer, the second transparent adhesive layer 42 is preferably an acrylic resin, and the second transparent barrier layer 44 is preferably PET.

The indicator layer 26 comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition sensitive indicator material; the condition sensitive indicating material is preferably an oxygen sensitive indicating material, and specifically, the oxygen sensitive indicating material includes an oxygen sensitive reactive dye, a photocatalyst material and an electron donor material. Further, the oxygen sensitive active dye is at least one of thiazine dye, oxazine dye, azine dye and indophenol dye, the photocatalyst material is at least one of nano titanium dioxide, nano strontium titanate, nano tin oxide, nano tungsten oxide and nano zinc oxide, and the electron donor material is at least one of disodium ethylene diamine tetraacetate, triethanolamine, glucose, fructose, polyvinyl alcohol, polyhydric alcohol, trihydroxyhexane and citric acid.

The oxygen-sensitive color change indicator of the sixth preferred embodiment is formed and then activated by irradiation with UV light having a wavelength of about 380 nm.

In use, the manufacturer attaches the color change indicator after removal of the peel layer 20 to the product or to the package, and as the product is distributed in the market, the consumer detaches the second transparent barrier layer 44 when unsealing the sealed package, at which time the color change indicator is activated. The reference portion 262 is not covered by the barrier layer and reacts with oxygen to quickly change to the end point color to form the reference portion 262, and the indicator portion 260 is covered by the transparent protective layer 27 to change to the end point color at a slower rate. The color change period of the indicator portion 260 is the shelf life of the product after the sealed package is opened, and the consumer can safely use the product in the color change period of the color change indicator.

The present invention further provides a seventh preferred embodiment of the color change indicating device, referring to fig. 6, fig. 6 is a schematic structural diagram of the seventh preferred embodiment of the color change indicating device of the present invention; in the seventh preferred embodiment, the color change indicator includes a reference layer 60, a covering layer 62 disposed on the reference layer 60, a transparent substrate layer 24 disposed on the covering layer 62, an indicating layer 26 disposed on the substrate layer 24, a first transparent adhesive layer 28 disposed on the indicating layer 26 and being air-permeable, and a first transparent barrier layer 29 disposed on the first transparent adhesive layer 28 and being air-permeable, wherein a first hollow portion 600 is disposed on the reference layer 60, and a second hollow portion 620 corresponding to the first hollow portion 600 is disposed on the covering layer 62.

Further, the color change indicator further comprises a third adhesive layer 22 arranged on the side of the reference layer 60 far away from the covering layer 62 and a peeling layer 20 capable of peeling off the side of the third adhesive layer 22 far away from the reference layer 60, wherein the third adhesive layer 22 is used for bonding the color change indicator on a product package.

Further, preferably, the reference layer 60 is a reference color block having at least two fixed colors, and the cover layer 62 is a white ink cover layer, so that the interference of the color change of the indication layer 26 on the reference layer 60 can be avoided by the cover layer 62. The color of the indication layer 26 can be observed by the consumer through the first and second hollow-outs 600 and 620.

The indicator layer 26 comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicator material; the condition-sensitive indicator material is preferably a carbon dioxide-sensitive indicator material, and in particular, the carbon dioxide-sensitive indicator material includes a first PH-sensitive dye and a phase transfer catalyst. Further, the first PH sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, cetyltrimethylammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101, and thymol blue, wherein the cetyltrimethylammonium cation may be generated from trimethylhexadecylammonium bromide or trimethylhexadecylammonium chloride. The phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate. Further, the optional thermoplastic polymer is polyethylene, polypropylene, polyethylene oxide, polycarbonate, polyether, polyester, polyamide, or polyoxymethylene. The inorganic pigment is hydrophobic inorganic pigment particles or hydrophilic inorganic pigment particles, and the optional hydrophobic inorganic pigment particles are at least one of titanium dioxide, silicon dioxide, aluminum oxide, cadmium red, cadmium yellow, Prussian blue, chrome yellow, carbon black and zinc white. It is to be understood that other inorganic pigments having specific hydrophobic characteristics may also be used as the hydrophobic inorganic pigment of the present invention. The hydrophilic inorganic pigment particles are at least one of silica, alumina, red iron oxide and yellow iron oxide. It is to be understood that other inorganic pigments having specific hydrophilic characteristics may also be used as the hydrophilic inorganic pigment of the present invention.

The inorganic pigment particles described above serve three functions: firstly, the micro-uneven surface has adsorbability and can adsorb active dye; second, different inorganic pigment particles have different affinities for water, and the selection of inorganic pigment particles that are consistent with the affinity of the thermoplastic polymer for water can improve the compatibility of the thermoplastic polymer and the inorganic pigment; and thirdly, the inorganic pigment has stable color, the color C can be obtained after the inorganic pigment of the color A and the reactive dye of the color B are mixed according to the principle of a pigment subtractive method, and the shade of the color C is closely related to the ratio of the pigment A to the dye B. Therefore, by adding at least one inorganic pigment with different proportions, the indicating layer 26 can realize colorful initial color effect and color change effect, thereby realizing color diversification of the indicating layer 26. In addition, the inorganic pigment of the present invention has good thermal stability, does not decompose during the hot melting and extrusion of the thermoplastic polymer, and does not physically or chemically react with other components.

In the carbon dioxide sensitive color change indicating device of the seventh preferred embodiment, when in use, a manufacturer attaches the color change indicating device with the peeling layer 60 peeled off to the inner wall of the modified atmosphere package, puts in the product and injects carbon dioxide gas, and then the product is sealed and enters the market for circulation. The indicator layer 26 of the color change indicator reacts with the high concentration of carbon dioxide in the modified atmosphere package to form an initial color.

When a consumer purchases a product, the color change indicating device can be checked through the transparent packaging bag, the color of the indicating layer 26 is in the initial color, the sealing performance of the packaging bag is good, the quality guarantee period marked on the packaging bag is effective, after the consumer opens the packaging bag, carbon dioxide gas in the color change indicating device slowly seeps outwards, the color changes and gradually changes to the end color, the color change period can be adjusted by adjusting the material and the thickness of the first transparent blocking layer 29, the color change period can be from several minutes to several months, the color change period is the quality guarantee period of the product after the product is opened, and the consumer can safely use the product in the color change period of the color change indicating device.

The consumer sees through the package that the indicator layer 26 is between the initial and end colors, indicating that the package is poorly sealed and the product is not fresh but still usable. If the color of the indicator layer 26 changes to the end color, it indicates that the product has deteriorated and is unusable.

It should be noted that, in the first preferred embodiment to the seventh preferred embodiment, there is a transparent protection layer, and the transparent protection layer is not limited to any material as long as it is transparent and air-permeable and has a neutral PH value.

In addition, the first to seventh preferred embodiments of the color change indicating device of the present invention and other preferred embodiments appropriately modified according to the concept of the present invention are not limited to be applied to the indication of freshness of food, medicine, beverage and other products, but can be applied to other products having a life cycle or directly applied to other products as a timing device.

The present invention further provides a method for manufacturing a color change indicator, referring to fig. 7a to 7h, and referring to fig. 2, fig. 7a to 7h are schematic diagrams illustrating a manufacturing process of a preferred embodiment of the method for manufacturing a color change indicator according to the present invention. In the preferred embodiment, the method for preparing the color change indicator comprises the following steps:

selecting a self-adhesive material with polyethylene terephthalate (PET) or polyvinyl chloride (PVC) as a substrate layer 24 as a printing stock, thereby forming a stripping layer 20, a third adhesive layer 22 and the substrate layer 24 of the color change indicating device, as shown in fig. 7 a;

printing an indicating ink and a reference color on the surface of the substrate layer 24 to form an indicating portion 260 and a reference portion 262, respectively, as shown in fig. 7 b;

transparent alumite with neutral PH value is thermoprinted above the indicating part 260 to form a transparent protective layer 27, so that chemical components with acidic PH values in the first transparent adhesive layer 28 are prevented from causing negative influence on PH sensitive components in the indicating material, as shown in FIG. 7 c;

compounding the low density polyethylene pre-coated film to form the first transparent adhesive layer 28 and the first transparent barrier layer 29 of the color change indicator device, as shown in fig. 7 d;

partially printing the silicone polymer to form the transparent release layer 40, and reducing the adhesive force of the second transparent adhesive layer 42, as shown in fig. 7 e;

die cutting and removing excess scrap edge, as shown in FIG. 7 f;

compounding a polyvinyl chloride (PVC) pre-coated film printed with a pattern on a surface layer of a silicone polymer to form a second transparent adhesive layer 42 and a second transparent barrier layer 44, the second transparent adhesive layer 42 and the second transparent barrier layer 44 serving as a starting part, which can prevent the penetration of sensitive gases, as shown in fig. 7 g;

and (5) die cutting and forming, namely removing redundant rim charge, so that the color change indicating device has a hand grip which is convenient for a user to peel off, as shown in fig. 7 h.

At this point, the consumer can easily peel away the second transparent barrier layer 44 with a protruding grip, thereby activating the color change indicator device.

In summary, the color change indicating device of the present invention has the following advantages:

the permeation of the sensitive gas of the indicating layer 26 becomes controllable, so that the color change period of the indicating layer can be adjusted according to different products, and the application range of the color change indicating device is improved; the base layer 24 has good air tightness, so that the permeation of sensitive gas has unidirectionality; the base layer 24 has good transparency so that when the color change indicator is placed inside the package, the consumer can view the color of the indicator portion through the package material and the base layer material; the first transparent barrier layer 29 has semi-permeable sealing performance, and a color change period of several minutes to several months can be obtained by arranging the first transparent barrier layer 29, so that the freshness indication requirement of most products can be met; the color change period of the color change indicating device is the same as the shelf life of the product, so that the shelf life of the product after the sealed package is opened is visual and obvious; a transparent protective layer 27 with neutral PH value is arranged above the indicating layer, so that the negative influence of chemical components with acidic PH value in the adhesive layer on PH sensitive components in the indicating material is avoided; the second transparent barrier layer 44 has good air tightness as a starting part, can isolate sensitive gas, can be stripped, and can start the color change indicating device after stripping; the color change indicating device has reversibility through condition excitation and has a high anti-counterfeiting effect; a reference part 262 is arranged around the indication part 260 to form a colorimetric system, so that the freshness of the product is visual and obvious; the reference portion 262 may be printed with a normal ink or may be made of an indicating material not covering the transparent protective layer 27; the first transparent barrier layer 29 may be provided in both peelable and non-peelable types as required.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A colour-change indicating device comprising a substrate layer and an indicating layer provided on the substrate layer, the indicating layer comprising an indicating portion and a reference portion, the reference portion being of at least two fixed colours;

the indicating part can react with carbon dioxide, ammonia gas or oxygen and presents different colors along with the increase of the reaction time, and the color change degree and the reaction time are in a linear relation;

2. A color change indicator device according to claim 1 further comprising a transparent protective layer having a neutral PH and being gas permeable disposed over the indicating portion, a first transparent adhesive layer disposed over the transparent protective layer and the reference portion and being gas permeable, and a first transparent barrier layer disposed over the first transparent adhesive layer and being gas permeable.

3. A color change indicator device according to claim 2 wherein the indicator portion is a carbon dioxide sensitive indicator material comprising a first PH sensitive dye which is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, cetyltrimethylammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue and a phase transfer catalyst which is at least one of a quaternary ammonium salt, sodium hydroxide and sodium bicarbonate.

4. A color change indicator device according to claim 2 further comprising a transparent release layer disposed on the first transparent barrier layer, a second transparent adhesive layer peelably disposed on the transparent release layer, and a second transparent barrier layer disposed on the second transparent adhesive layer.

5. A colour-change indicator device as claimed in claim 4,

the indicating portion is an ammonia-sensitive indicating material comprising a second PH-sensitive dye that is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue, and m-cresol purple, and a volatile basic substance that is at least one of ammonium hydroxide, propylamine, n-butylamine, n-hexylamine, and n-octylamine; or,

6. A colour-change indicating device as claimed in claim 2, further comprising a transparent release layer provided between the reference portion and the first transparent adhesive layer.

7. The color change indicator device of claim 6, wherein the indicator portion is an ammonia sensitive indicator material comprising a second pH sensitive dye that is at least one of bromophenol blue, bromocresol green, bromocresol purple, bromothymol blue, thymol blue, and m-cresol purple.

8. A colour-change indicator according to any one of claims 1 to 7 further comprising a third adhesive layer provided on the side of the substrate layer remote from the indicator layer and a release layer releasably provided on the side of the third adhesive layer remote from the substrate layer, the third adhesive layer being adapted to bond the colour-change indicator after release to an article.

9. A colour change indicator device comprising a substrate layer, an indicator layer and a transparent protective layer which is gas permeable and neutral in PH, the indicator layer being provided on the substrate layer and comprising a reference portion and an indicator portion, the transparent protective layer being provided on the indicator portion;

the reference portion and the indicating portion are made of the same material;

the indicating part is used for reacting with carbon dioxide, ammonia gas or oxygen which penetrates through the transparent protective layer and presents different colors along with the increase of the reaction duration, and the color change degree and the reaction duration are in a linear relation;

10. A colour-change indicator device as claimed in claim 9, wherein the indicating portion comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicating material; the condition sensitive indicating material is a carbon dioxide sensitive indicating material, the carbon dioxide sensitive indicating material comprises a first PH value sensitive dye and a phase transfer catalyst, the first PH value sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, hexadecyl trimethyl ammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, and the phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate.

11. A color change indicator device according to claim 9 further comprising a transparent release layer disposed on the transparent protective layer and the reference portion, a second transparent adhesive layer peelably disposed on the transparent release layer, and a second transparent barrier layer disposed on the second transparent adhesive layer.

12. A colour-change indicator device as claimed in claim 11, wherein the indicating portion comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicating material; the condition sensitive indicating material is an oxygen sensitive indicating material, the oxygen sensitive indicating material comprises an oxygen sensitive active dye, a photocatalyst material and an electron donor material, the oxygen sensitive active dye is at least one of thiazine dye, oxazine dye, azine dye and indophenol dye, the photocatalyst material is at least one of nano titanium dioxide, nano strontium titanate, nano tin oxide, nano tungsten oxide and nano zinc oxide, and the electron donor material is at least one of disodium ethylene diamine tetraacetate, triethanolamine, glucose, fructose, polyvinyl alcohol, polyhydric alcohol, trihydroxyhexane and citric acid.

13. A colour-change indicator according to any one of claims 9 to 12 further comprising a third adhesive layer provided on the side of the substrate layer remote from the indicator layer and a release layer releasably provided on the side of the third adhesive layer remote from the substrate layer, the third adhesive layer being adapted to bond the colour-change indicator after release to an article.

14. The color change indicating device is characterized by comprising a reference layer, a transparent substrate layer arranged on the reference layer, an indicating layer arranged on the substrate layer, a first transparent adhesive layer arranged on the indicating layer and permeable to air, and a first transparent barrier layer arranged on the first transparent adhesive layer and permeable to air, wherein the reference layer has at least two fixed colors and is provided with a first hollow part;

the indicating layer is used for reacting with carbon dioxide, oxygen or ammonia gas and presents different colors along with the increase of the reaction duration, and the color change degree and the reaction duration are in a linear relation;

15. A colour-change indicator device as claimed in claim 14, further comprising a cover layer disposed between the reference layer and the base layer, the cover layer having a second aperture corresponding to the first aperture.

16. A colour-change indicator device as claimed in claim 14 or 15,

the indicator layer comprises a thermoplastic polymer and a chemical indicator comprising an inorganic pigment and a condition-sensitive indicator material; the condition sensitive indicating material is a carbon dioxide sensitive indicating material which comprises a first PH value sensitive dye and a phase transfer catalyst, wherein the first PH value sensitive dye is at least one of m-cresol purple, thymolphthalein, o-cresol phthalein, bromothymol blue, cresol red, hexadecyl trimethyl ammonium cation, neutral red, phenol red, rhodamine, sulforhodamine 101 and thymol blue, and the phase transfer catalyst is at least one of quaternary ammonium salt, sodium hydroxide and sodium bicarbonate;