초록 ▼

Compositions, devices and processes related to etching of a very thin layer or fine particles of a metal are disclosed for monitoring a variety of parameters, such as time, temperature, time-temperature, thawing, freezing, microwave, humidity, ionizing radiation, sterilization and chemicals. These d

Compositions, devices and processes related to etching of a very thin layer or fine particles of a metal are disclosed for monitoring a variety of parameters, such as time, temperature, time-temperature, thawing, freezing, microwave, humidity, ionizing radiation, sterilization and chemicals. These devices have capabilities of producing a long and sharp induction period of an irreversible visual change. The devices are composed of an indicator comprising a very thin layer of a metal and an activator, e.g., a reactant, such as water, water vapor, an acid, a base, oxidizing agent or their precursors, which is capable of reacting with the said indicator. Ink formulations composed of a metal powder and a proper activator can be used for monitoring several sterilization processes, such as sterilization with steam. When water is used as an activator, a thin layer of metals, such as that of aluminum can be used as steam sterilization or humidity indicator.

대표청구항 ▼

1. An indicating system comprising: a zero-valent opaque metal or metal alloy indicator layer; andan activator layer comprising an activator or a precursor of said activator wherein said activator or said precursor of said activator renders said indicator layer transparent upon reaction. 2. The indi

1. An indicating system comprising: a zero-valent opaque metal or metal alloy indicator layer; andan activator layer comprising an activator or a precursor of said activator wherein said activator or said precursor of said activator renders said indicator layer transparent upon reaction. 2. The indicating system of claim 1 wherein the indicator layer comprises a material that has at least one property selected from the group consisting of conductive, reflective, highly opaque, self binding and impermeable and further has a property of being able to be etched or destroyed when contacted with the activator or said precursor of said activator. 3. The indicating system of claim 1 wherein the reaction product after the indicator layer is contacted with the activator or said precursor of said activator has at least one property selected from the group consisting of being non-conductive, non-reflective and permeable. 4. The indicating system of claim 1 wherein the metal or metal alloy is selected from the group consisting of alkali metals, alkaline earth metals, transition metals, post transition metals, lanthanides and actinides metals and their alloys. 5. The indicating system of claim 4 wherein the metal is selected from the group consisting of aluminum, tin, zinc, copper, manganese, magnesium, nickel, cobalt, iron, sodium, potassium, lithium, calcium, gallium, cesium, germanium, indium, silver and their alloys. 6. The indicating system of claim 5 wherein the metal is selected from the group consisting of aluminum, copper, zinc, tin and their alloy. 7. The indicating system of claim 4 wherein the metal or metal alloy reacts with water, acids, bases, chemicals, chemical or biological agents and salts. 8. The indicating system of claim 4 wherein the metal alloy is an alloy of aluminum. 9. The indicating system of claim 1 wherein the activator layer comprises a composition that reacts with the indicator layer to cause an irreversible change in the indicator layer. 10. The indicating system of claim 9 wherein the activator is a salt of a weak acid and a strong base, a strong acid and a weak base, a strong acid and a strong base, or a weak acid and a weak base or a combination thereof. 11. The indicating system of claim 1 wherein the activator comprises at least one agent selected from the group consisting of water, oxygen, organic acids, inorganic acids, bases, salts, biological agents and chelates. 12. The indicating system of claim 1 which comprises said precursor of the activator. 13. The indicating system of claim 12 which comprises a pre-precursor for said precursor for the activator. 14. The indicating system of claim 13 wherein the pre-precursor is white or yellow phosphorus. 15. The indicating system of claim 12 wherein the precursor for the activator is a monomeric or polymeric halo, halide, halonium, sulfonium or phosphonium compound. 16. The indicating system of claim 1 wherein the activator is an inorganic acid. 17. The indicating system of claim 16 wherein the inorganic acid is selected from the group consisting of phosphoric acid, phosphorous acid, hydrochloric acid, nitric acid, sulfuric acid, sulfonic acid, and a mixture thereof. 18. The indicating system of claim 1 wherein the activator is a hydroxide, alkoxide, or aryloxide of a metal or a cation of nitrogen. 19. The indicating system of claim 1 wherein the activator is selected from the group consisting of a halide, oxide, nitrate, nitrite, phosphate, phosphite, phosphonate, silicate, sulfate, bisulfate, sulfite, sulfide, bisulfide, sulfonate, cyanate, cyanide, thiocyanate, acetylacetonate, carboxylate, percarboxylate, carbonate or bicarbonate anion of a mono, di and trivalent cation of a metal or cation of nitrogen, sulfur, phosphorous, halogens and mixture thereof. 20. The indicating system of claim 1 wherein the activator is selected from the group consisting of ammonium bromide, ammonium thiocyanate, calcium chloride, copper chloride, copper ammonia complex, lithium acetylacetonate, lithium chloride, lithium formate, phosphorous, phosphorous pentoxide, potassium acetate, potassium benzoate, potassium bromide, potassium chloride, potassium ferrocyanide, potassium ferricyanide, potassium formate, sodium acetate, sodium bicarbonate, sodium bromide, sodium carbonate, sodium cyanate, sodium diethyldithiocarbamate, sodium iodide, sodium metasilicate, sodium nitrate, sodium sulfite, sodium tetrafluoroborate, sodium tetraborate, sodium thiocyanate, sodium thiosulfate, tetraethylammonium bromide, zinc chloride and a mixture thereof. 21. The indicating system of claim 1 wherein the activator is a chelate or complex of a metal cation. 22. The indicating system of claim 1 wherein the activator is an amine or ammonia complex of a metal cation. 23. The indicating system of claim 1 wherein the activator is an amine or ammonia complex of copper chloride or nickel chloride. 24. The indicating system of claim 1 wherein the activator layer is in close contact with or in proximity of the indicator layer. 25. The indicating system of claim 1 wherein the activator is oxygen, chemical vapor or water. 26. The indicating system of claim 1 wherein the activator is humidity, steam, or microwave radiation, and further wherein the activator or the precursor of the activator reacts directly with the indicator layer. 27. The indicating system of claim 1, wherein the activator comprises at least one agent selected from the group consisting of humidity, steam, ethylene oxide, formaldehyde, ozone, peracetic acid, hydrogen peroxide, a chemical agent and a biological agent. 28. The indicating system of claim 1 wherein the indicator layer is deposited on a substrate. 29. The indicating system of claim 28 wherein the substrate is a plastic film wherein said indicator layer is a continuous metal layer thickness of less than about 10,000 Angstroms. 30. The indicating system of claim 29 wherein the indicator layer is bound to said substrate to form a metallized plastic film. 31. The indicating system of claim 29 wherein the continuous metal layer has a thickness of less than about 1,000 Angstroms. 32. The indicating system of claim 28 wherein the metal or metal alloy is particulate with a thickness of less than about 10 microns. 33. The indicating system of claim 28 which comprises a second indicator layer on the other side of the substrate. 34. The indicating system of claim 1 which further comprises: a binder which binds the activator layer and indicator layer. 35. The indicating system of claim 1 wherein the indicator layer is affixed to a substrate. 36. The indicating system of claim 35 wherein the substrate is a plastic film. 37. The indicating system of claim 36 wherein the substrate comprises a pressure sensitive adhesive. 38. The indicating system of claim 1 which further comprises a binder for the activator. 39. The indicating system of claim 38 wherein the activator layer is affixed to a substrate. 40. The indicating system of claim 1 which further comprises: a) an indicator tape affixed to a first substrate wherein said indicator tape comprises said indicator layer; andb) an activator tape affixed to a second substrate wherein said second substrate having thereon said activator layer composed of a matrix layer containing said activator or the precursor of the activator wherein said indicator tape and said activator tape are bonded together with at least one adhesive. 41. The indicating system of claim 40 which further comprises an adhesive layer to attach the indicating system to an item to be monitored. 42. The indicating system of claim 40 further comprising at least one electronic chip or component connected to a conductive path. 43. The indicating system of claim 40 wherein said activator tape is applied on at least a portion of at least one conductive path of an electronic device composed of at least one electronic chip wherein the activator or the precursor of the activator has capability of destroying the conductive path. 44. The indicating system of claim 43 wherein the electronic device is a radio frequency identification device or an electronic article surveillance device. 45. The indicating system of claim 40 wherein the indicator tape and the activator tape comprise a sealing tape, said indicating system having a two tape dispenser for the sealing tape, wherein two tapes are dispensed simultaneously when applying the sealing tape on a container wherein one tape of said two tapes is said indicator tape and a second tape of said two tapes is said activator tape. 46. The indicating system of claim 1 which can monitor a material or a process. 47. The indicating system of claim 46 wherein the material is, a chemical, a chemical agent or a biological agent. 48. The indicating system of claim 47 wherein the chemical agent is a lethal agent, a blister causing agent, a blood affecting agent, a nerve agent, a pulmonary agent, an incapacitating agent or a riot control agent. 49. The indicating system of claim 48 wherein the chemical agent is selected from the group consisting of cyanogen chloride, hydrogen cyanide, ethyldichloroarsine, methyldichloroarsine, phenyldichloroarsine, Lewisite, 1,5-dichloro-3-thiapentane, 1,2-bis(2-chloroethylthio)ethane, 1,3-bis(2-chloroethylthio)-n-propane, 1,4-bis(2-chloroethylthio)-n-butane, 1,5-bis(2-chloroethylthio)-n-pentane, 2-chloroethylchloromethylsulfide, bis(2-chloroethyl)sulfide, bis(2-chloroethylthio)methane, bis(2-chloroethylthiomethyl)ether, bis(2-chloroethylthioethyl)ether, bis(2-chloroethyl)ethylamine, bis(2-chloroethyl)methylamine, tris(2-chloroethyl)amine, tabun, cerin sarin, soman, cyclosarin, GV, VE, VG, VM, VR, VX chlorine, chloropicrin, phosgene, diphosphene, agent 15 (BZ), EA 3167, kolokol-1, pepper spray, CS gas, CN gas and CR gas. 50. The indicating system of claim 47 wherein the chemical agent is a toxic industrial chemical. 51. The indicating system of claim 50 wherein the toxic industrial chemical is selected from the group consisting of acetone cyanohydrin, acrolein, acrylonitrile, allyl alcohol, allyl amine, allyl chlorocarbonate, allyl isothiocyanate, ammonia, arsenic trichloride, arsine, boron tribromide, boron trichloride, boron trifluoride, bromine, bromine chloride, bromine pentafluoride, bromine trifluoride, carbon disulfide, carbon monoxide, carbonyl fluoride, carbonyl sulfide, chlorine, chlorine pentafluoride, chlorine trifluoride, chloroacetaldehyde, chloroacetone, chloroacetonitrile, chloroacetyl chloride, chlorosulfonic acid, crotonaldehyde, cyanogen, 1,2-dimethyl hydrazine, diborane, diketene, dimethyl sulfate, diphenylmethane-4′-diisocyanate, ethyl chloroformate, ethyl chlorothioformate, ethyl phosphonothioicdichloride, ethyl phosphonous dichloride, ethylene dibromide, ethylene imine, ethylene oxide, fluorine, formaldehyde, hexachlorocyclopentadiene, hydrogen bromide, hydrogen chloride, hydrogen cyanide, hydrogen fluoride, hydrogen iodide, hydrogen selenide, hydrogen sulfide, iron pentacarbonyl, isobutyl chloroformate, isopropyl chloroformate, isopropyl isocyanate, methanesulfonyl chloride, methyl bromide, methyl chloroformate, methyl chlorosilane, methyl hydrazine, methyl isocyanate, methyl mercaptan, n-butyl chloroformate, n-butyl isocyanate, nitric acid, fuming, nitric oxide, nitrogen dioxide, n-propyl chloroformate, parathion, perchloromethyl mercaptan, phosgene, phosphine, phosphorus oxychloride, phosphorus pentafluoride, phosphorus trichloride, sec-butyl chloroformate, selenium hexafluoride, silicon tetrafluoride, stibine, sulfur dioxide, sulfur trioxide, sulfuric acid, sulfuryl chloride, sulfuryl fluoride, tellurium hexafluoride, tert-butyl isocyanate, tert-octyl mercaptan, tetraethyl lead, tetraethyl pyrophosphate, tetramethyl lead, titanium tetrachloride, toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, trichloroacetyl chloride, trifluoroacetyl chloride and tungsten hexafluoride. 52. The indicating system of claim 46 wherein the process is time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 53. The indicating system of claim 52 wherein the process of time-temperature is used for monitoring shelf life, usability, freshness, of perishables comprising one or more of fresh, refrigerated, or frozen, vegetables, fruits, meats, fish, poultry, dairy products, bakery products, juices, pre-cooked foods, soft and alcoholic beverages, and the non-food item is a pharmaceutical, vaccine, biological sample, cosmetics, reactive chemical compound, biochemical product, battery, x-ray film or photographic film. 54. The indicating system of claim 53 wherein the biological sample is sera, blood, or blood plasma. 55. The indicating system of claim 1 which has at least one message which appears as in color, word or symbol on at least on one side of the indicator layer. 56. The indicating system of claim 55 wherein the message is on both sides of the indicator layer. 57. The indicating system of claim 56 which contains at least two messages wherein a first message of said two messages does not start to appear at a same time as a second message of said two messages. 58. The indicating system of claim 57 wherein a first appearing message indicates a status or quality of an item when the indicating system is applied on or before a treatment of the item and a second appearing message alone or in combination with the first indicates status or quality of the item after the treatment. 59. The indicating system of claim 58 wherein the first appearing message indicates un-doneness, freshness, usability, acceptability, untreated, unexposed, or non-sterile, non-usability, not-acceptability and the second appearing message alone or in combination with the first indicates doneness, expiration, spoilage, not usability unacceptability, treated, and exposed, sterile, usability and acceptability. 60. The indicating system of claim 1 which further comprises a) a binder, andb) at least one substrate;wherein the metal or metal alloy is in the form of particles. 61. The indicating system of claim 1 wherein the indicator layer further comprises indicating ink, paint, gel, or plastisol. 62. The indicating system of claim 61 wherein the indicating system has a liquid vehicle. 63. The indicating system of claim 1 wherein the precursor for the activator is an acid, base, salt, organo-metallic compound or a chemical agent or a biological agent. 64. The indicating system of claim 63 wherein the precursor for the activator is phosphorous pentoxide. 65. The indicating system of claim 1 which further comprises a system wherein an additional one or more layers are added to the system, wherein the additional layers are selected from the group consisting of a binder layer, a permeable to activator layer, a wedge shaped permeable to activator layer, a barrier to activator layer, a reactive, destroyable or degradable barrier layer, an expiration indicating layer, a tamper indicating layer, an activation indicating layer, a message or image creating layer, separating layer, removable layer, naturally formed oxide layer, a disappearing layer, activatable layer, a microencapsulated layer and a thermally printable layer. 66. The indicating system of claim 1 which further comprises a substrate with a printed message. 67. The indicating system of claim 1 wherein a time required for a change in the indicator layer or an activation energy of the system is varied or adjusted by changing one or more of the parameters selected from the group consisting of: thickness of the activator layer, thickness of the indicator layer, thickness of the permeable layer, concentration of the activator, concentration of the precursor, concentration of an additive in the activator, concentration of an additive in the permeable layer, nature of a solvent, surfactant and a catalyst, nature of the activator layer, nature of the indicator layer, nature of the permeable layer, nature of the additive and nature of a reaction accelerator and retarder. 68. The indicating system of claim 1 which is a high accuracy optical waveguide monitor, an electronic circuit or an electronic article surveillance. 69. The indicating system of claim 1 which is a safety sticker, self-timing retail sticker, biological industrial process monitor, self-expiring sticker to prevent re-use, security ID label, visitors badge, self-expiring parking tag, package and shipping label, wrist band, time indicating ticket for trains, buses, spot events, theaters, self-expiring pass for tours, emergency rooms, hospitals, museums, and other locations, race track pass, security label for screened luggage, purse, bag at airports to indicate that such items have been inspected, or a self-expiring visitor label issued at unmanned but video controlled entrances for visitors. 70. The indicating system of claim 1 which is a toy, gimmick, message, pattern, design, gift card, or greeting card. 71. The indicating system of claim 1 which is a part of an radio frequency identification device, electronic article surveillance or printed circuit board. 72. The indicating system of claim 1 which is a device to monitor radon and alpha particles. 73. The indicating system of claim 1 wherein the activator layer is on a substrate. 74. The indicating system of claim 73 wherein there is a second activator layer on the other side of the substrate. 75. The indicating system of claim 1 which is an indicating device for different classes of sterilization. 76. The indicating system of claim 1 wherein the metal or metal alloy indicator layer is destructible; and further comprising a destructible barrier layer over the metal or metal alloy indicator layer. 77. The indicating system of claim 76 wherein the metal or metal alloy indicator and barrier layers are irreversibly destructible. 78. The indicating system of claim 76 wherein the destructible barrier layer is impermeable. 79. The indicating system of claim 78 wherein the barrier layer is an oxide layer. 80. The indicating system of claim 76 wherein the barrier layer is a destructible oxide layer. 81. The indicating system of claim 80 wherein the oxide layer is impermeable to the activator layer. 82. The indicating system of claim 76 wherein the barrier layer is capable of providing an induction period which is measured by a delay in a visual indication of the destruction of the metal or metal alloy indicator layer. 83. The indicating system of claim 82 wherein the barrier layer is an oxide layer. 84. A process to monitor the status of medical products, food, or biological waste which comprises placing an indicating system comprising: a zero-valent metal or metal alloy indicator layer; anda layer of an activator or a precursor of said activator on a packaging of said medical products, food, or biological waste. 85. A process to monitor the presence or absence of a toxic chemical, an agent or water which comprises: placing an indicating system comprising a zero-valent metal or metal alloy indicator layer, a layer of an activator or a precursor of said activator, and a metal oxide layer between the metal or metal alloy indicator layer and the layer of said activator or said precursor of said activator in the area to be monitored; andmonitoring the indicating system for a physical change in said indicator layer. 86. A process to monitor the status of a perishable item which comprises: placing an indicating system comprising a zero-valent metal or metal alloy indicator, a layer of an activator or a precursor of said activator and a metal oxide layer between the metal or metal alloy indicator layer and the layer of said activator or said precursor of said activator on or near the perishable item wherein the perishable item is a food item, or a nonfood item; andmonitoring physical change in a physical property of said indicator layer. 87. A process to monitor a limited time consumer use for items that have been opened or in use and should be used within a certain period comprising: placing an indicating system comprising a zero-valent opaque metal or metal alloy indicator and a layer of an activator or a precursor of said activator, near an item to be monitored, wherein the item is selected from the group consisting of drinks, food items, health, personal and family care products wherein when said indicator becomes transparent said certain period has expired. 88. A process to make an indicating system comprising a zero-valent metal or metal alloy indicator layer and a layer of an activator or a precursor of said activator comprising: laminating an activator tape comprising said layer of said activator or said precursor of said activator on said metal or metal alloy indicator layer. 89. A process to make an indicating system comprising a zero-valent metal or metal alloy indicator layer and a layer of an activator or a precursor of said activator comprising: coating said layer of activator or precursor of said activator on said metal or metal alloy indicator layer wherein said metal or metal alloy indicator is on a support;coating onto said support at least one additional layer selected from the group consisting of a permeable layer, a wedge shaped permeable layer, a barrier layer, a reactive, destroyable or degradable barrier layer, an expiration indicating layer, a tamper indicating layer, an activation indicating layer, a message or image creating layer, separating layer, removable layer, naturally formed oxide layer, a disappearing layer, activatable layer, a microencapsulated layer and a thermally printable layer. 90. The process to make the indicating system of claim 89 which further comprises applying an additional layer. 91. A process to determine the concentration of an agent comprising: monitoring a change in conductivity, or opacity of an indicator layer of an indicating system comprising a zero-valent metal or metal alloy indicator layer and a layer of an activator or a precursor of said activator. 92. A process to monitor a change in a material or a process comprising: measuring a change in the material or the process with an indicating system comprising a zero-valent metal or metal alloy indicator layer and a layer of an activator or a precursor of said activator. 93. The process of claim 92 wherein the material is a perishable, a medical product, a chemical, a chemical agent or a biological agent. 94. The process of claim 92 wherein the process is a change in time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 95. The process of claim 94 wherein the change of time-temperature is monitored to indicate shelf life of perishables comprising one or more of fresh, refrigerated, or frozen, vegetables, fruits, meats, fish, poultry, dairy products, bakery products, juices, pre-cooked foods, soft and alcoholic beverages, pharmaceutical, vaccine, biological sample, cosmetics, reactive chemical compound, biochemical product, battery, x-ray film or photographic film. 96. The process of claim 95 wherein the biological sample is sera, blood, or blood plasma. 97. The process of claim 92 wherein the indicating system further comprises an adhesive layer to attach the indicating system to an item to be monitored. 98. The process of claim 92 wherein the indicating system further comprises a substrate having the metal or metal alloy indicator layer, a patterned layer of a barrier material and the layer of said activator or said precursor of said activator, wherein when activated, the barrier material protects certain areas selected by the pattern on the indicator layer, allowing the remaining metal or metal alloy layer to create a message or at least one conductive path for an electronic device, or a metal or metal alloy pattern. 99. The process of claim 98 wherein the indicating system further comprises at least one electronic chip or component connected to the conductive path. 100. The process to monitor a change in a material or a process of claim 92 wherein the indicating system further comprises an induction period which is measured by a delay in a visual indication of the change in the material or process. 101. The process of claim 100 wherein the induction period in the indicating system is created by the destruction of the destructible metal or metal alloy layer. 102. The process of claim 101 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 103. The process of claim 100 wherein the indicating system comprises a destructible metal or metal alloy indicator layer, a destructible barrier layer, and the layer of the activator or the precursor of said activator and the induction period is created by the destruction of the destructible barrier layer. 104. The process of claim 103 wherein the destructible barrier layer is an oxide layer. 105. The process of claim 104 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 106. The process of claim 103 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 107. The process of claim 100 wherein the indicating system comprises a destructible metal or metal alloy indicator layer, a destructible barrier layer, and the layer of the activator or the precursor of said activator and the induction period is created by the destruction of the destructible metal or metal alloy indicator layer and the destructible barrier layer. 108. The process of claim 107 wherein the destructible barrier layer is an oxide. 109. The process of claim 108 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 110. The process of claim 107 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 111. The process of claim 100 wherein the indicating system comprises a destructible metal or metal alloy indicator layer, a permeable layer, and the layer of the activator or the precursor of said activator and the induction period is created by the destruction of the destructible metal or metal alloy layer. 112. The process of claim 111 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 113. The process of claim 100 wherein the indicating system comprises a destructible metal or metal alloy indicator layer, a destructible barrier layer, a permeable layer, the layer of the activator or the precursor of said activator and the induction period is created by the destruction of the destructible metal or metal alloy indicator layer, and the destructible barrier layer. 114. The process of claim 113 wherein the destructible barrier layer is an oxide. 115. The process of claim 114 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 116. The process of claim 113 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 117. The process of claim 100 which is a process of monitoring time, temperature, time-temperature, freeze, thaw, heating, cooling, humidity, doneness of food, microwave, pressure, radiation and sterilization including sterilization with steam, ethylene oxide, a peroxide, plasmas of a peroxide, formaldehyde, dry heat and ionizing radiation. 118. An indicating system comprising: a zero-valent opaque metal or metal alloy indicator layer wherein said metal is selected from the group consisting of aluminum, zinc and copper; anda layer of an activator or a precursor of said activator wherein said activator or said precursor renders said indicator transparent upon reaction with said activator.