Thermal transfer ribbons and direct thermal printing media including an environmental exposure indicator material

Abstract

THERMAL TRANSFER RIBBONS AND DIRECT THERMAL PRINTING SUBSTRATES INCLUDING AN INDICATOR MATERIAL FOR ENVIRONMENTAL EXPOSURE. The invention relates to a thermal paper for environmental exposure prepared by a process comprising the steps of: adding reversible thermochromic pigments to an acrylic binder and an aqueous-based solvent to create a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 18°C; and coating the thermal paper with the reversible thermochromic formulation. Figure for abbreviation: None

Description

Title of the invention: THERMAL TRANSFER RIBBONS AND DIRECT THERMAL PRINTING SUBSTRATES INCLUDING AN INDICATOR MATERIAL FOR ENVIRONMENTAL EXPOSURE

[0001] BACKGROUND

[0002] Printing systems include laser printers, thermal printers, and dot matrix printers. Laser printers pass a laser beam over paper or a substrate. Inkjet printing involves a process of propelling ink droplets onto paper or a substrate. Dot matrix printers use a print head that strikes an ink-impregnated ribbon, which is then pressed against the paper or substrate. Thermal transfer printing uses a heat-sensitive ribbon or thermal transfer ribbon and a thermal print head to apply the ribbon's ink to the paper or substrate. Direct thermal printing is a digital printing process that produces a printed image without a ribbon. Direct thermal printing uses a chemically treated, heat-sensitive substrate that forms an image (e.g., turns black) when it passes under the thermal print head.Thermal transfer ribbons and direct thermal printing are both used in marker and label applications to image various forms of data, such as images, readable text, barcode symbols, etc. High-resolution thermal printheads allow for the printing of more complex designs. Thermal transfer ribbons and direct thermal printing media can be used to print images in both black and color.

[0003] SUMMARY

[0004] This disclosure proposes a novel and innovative system, methods, and apparatus for thermal transfer ribbons and direct thermal media that include an indicator material for environmental exposure, together with methods for manufacturing and using the thermal transfer ribbons and direct thermal media to print data shapes, such as barcode symbols. In one aspect of this disclosure, an environmental thermal paper is prepared by a process comprising the steps of adding reversible thermochromic pigments to an acrylic binder and an aqueous-based solvent to create a reversible thermochromic formulation. The thermochromic formulation is configured to change color state from blue to colorless in response to a exposure to temperature above a threshold temperature of 18°C. The process also includes the step of coating thermal paper with the reversible thermochromic formulation.

[0005] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the acrylic binder is a clear, viscous acrylic resin solution.

[0006] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic formulation comprises one of 26 percent by weight of thermochromic pigments, 24.5 percent by weight of thermochromic pigments and 24 percent by weight of thermochromic pigments.

[0007] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic formulation comprises one of 44 percent by weight of the acrylic binder, 47 percent by weight of the acrylic binder and 49 percent by weight of the acrylic binder.

[0008] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic formulation has a viscosity (cps) between 150 cps and 300 cps.

[0009] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic formulation has a flow stress between 3.0 dynes / cm2 and 17 dynes / cm2.

[0010] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of imaging thermal paper with a dataform through at least one layer of a reversible thermochromic ink to create the environmental exposure dataform. The reversible thermochromic ink is configured to change color state from blue to colorless in response to exposure to a temperature above a threshold temperature of 18°C.

[0011] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the reversible thermochromic ink is formed by mixing thermochromic pigments with an acrylic binder and an aqueous-based solvent.

[0012] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the acrylic binder is a clear, viscous acrylic resin solution.

[0013] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic ink comprises one of 26 percent by weight of thermochromic pigments, 24.5 percent by weight of thermochromic pigments and 24 percent by weight of thermochromic pigments.

[0014] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic ink comprises one of 44 percent by weight of the acrylic binder, 47 percent by weight of the acrylic binder and 49 percent by weight of the acrylic binder.

[0015] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic ink has a viscosity (cps) between 150 cps and 300 cps.

[0016] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermochromic ink has a flow stress between 3.0 dynes / cm2 and 17 dynes / cm2.

[0017] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a label comprises a flexible substrate including a first face and a second face. The first face is an adhesive, the second face is configured to be printed with a first visible mark, and the second face has a second overlapping printed mark. The overlapping mark is configured to change opacity below a first transition temperature to obscure the visible mark.

[0018] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the overlapping mark changes opacity from opaque to transparent at a second transition temperature, the second transition temperature being the same as the first transition temperature.

[0019] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the overlapping mark changes from opaque to transparent at a second transition temperature, the second transition temperature being higher than the first transition temperature.

[0020] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive is configured to fix the label to a bottle, and the second transition temperature is configured to change opacity when a liquid inside the bottle reaches 18°C.

[0021] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the flexible substrate includes a thermochromic layer configured to be printed by a thermal printer at an imaging temperature.

[0022] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the flexible substrate includes a top coating configured to be printed by a thermal printer.

[0023] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the visible mark is light blue and the overlapping mark, when opaque, is dark blue.

[0024] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the flexible substrate is a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead, the thermal paper substrate having an imaging temperature and being capable of changing color when heated by the thermal printhead heated to or above the imaging temperature.

[0025] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the label further includes an environmental exposure indicator disposed on the thermal paper substrate, the environmental exposure indicator comprising an environmental exposure indicator material configured to change color state in response to exposure to temperature above a predetermined threshold temperature, which is below the imaging temperature.

[0026] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator for environmental exposure is the overlapping mark.

[0027] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to the environment is a dye encapsulated in a matrix.

[0028] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material is selected from the group consisting of (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0029] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the group further consists of (f) an indicator material configured to change color state in response to exposure to radiation, (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength, and (h) an indicator material configured to change color state in response to exposure to moisture.

[0030] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material is (a), and the flexible substrate is configured to image a form of data, preferably a barcode, on the flexible substrate at an imaging temperature above the threshold temperature without the environmental exposure indicator material changing color state.

[0031] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the form of data is the visible mark.

[0032] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material is (a), and the environmental exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range selected from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0033] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0034] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0035] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0036] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head has a heated heat transfer temperature that is in the selected range in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0037] The print head is configured to heat at least a part of the label to a heated heat transfer temperature which is in the range chosen in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0038] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetyl, an alkane, a wax, an ester, or combinations thereof.

[0039] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

[0040] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to the environment has a particle size between 400 nm and 600 nm.

[0041] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material has a concentration, in a layer applied to the direct thermal printer material, in the range selected from the group consisting of approximately 10 to 60 wt%, approximately 20 to 60 wt%, approximately 25 to 60 wt%, approximately 30 to 60 wt%, approximately 35 to 60 % by weight, approximately 40 to 60% by weight, approximately 30 to 60% by weight, approximately 30 to 55% by weight, approximately 30 to 50% by weight, approximately 30 to 45% by weight, approximately 40 to 55% by weight, approximately 40 to 50% by weight and approximately 45 to 50% by weight.

[0042] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is (c), and the second lower temperature threshold is in the range selected from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C.

[0043] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to the environment is disposed on the thermal paper substrate in the form of a thick (boiled) suspension of ink.

[0044] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet.

[0045] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from black to colorless above the threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C.

[0046] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from colorless to black above the threshold temperature of 65°C.

[0047] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from colorless to magenta above the threshold temperature of 85°C.

[0048] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is disposed on the thermal paper substrate in the form of an SCC emulsion.

[0049] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the SCC emulsion is arranged on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet.

[0050] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the SCC emulsion is configured to change color state from opaque white to colorless above the threshold temperature of 40°C.

[0051] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a thermal transfer ribbon for environmental exposure is prepared by a process comprising the steps of adding reversible thermochromic pigments to an acrylic binder and an IPA solvent matrix to create a reversible thermochromic formulation. The thermochromic formulation is configured to change color state from black to colorless in response to exposure to a temperature above a threshold temperature of 35°C. The process also includes coating a blank thermal transfer ribbon with the reversible thermochromic formulation.

[0052] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of performing a thermal printing operation on a thermal transfer ribbon to print a dataform onto a printing substrate, thereby creating the environmental exposure dataform. The thermal transfer ribbon comprises a layer of a reversible thermochromic formulation. The thermochromic formulation is configured to change color state from black to colorless in response to exposure to a temperature above a threshold temperature of 35°C.

[0053] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the reversible thermochromic formulation comprises reversible thermochromic pigments, an acrylic binder, and an IPA solvent matrix.

[0054] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a thermal transfer ribbon for environmental exposure is prepared by a process comprising the steps of adding reversible thermochromic pigments to an acrylic binder and an IPA solvent matrix to create a reversible thermochromic formulation. The thermochromic formulation is configured to change color state from blue to colorless in response to exposure to a temperature above a threshold temperature of 12°C. The process also includes coating a blank thermal transfer ribbon with the reversible thermochromic formulation.

[0055] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of performing a thermal printing operation on a thermal transfer ribbon to print a dataform onto a printing substrate, thereby creating the environmental exposure dataform. The thermal transfer ribbon includes a layer of a reversible thermochromic formulation. The thermochromic formulation is configured to change color state from blue to colorless in response to exposure to a temperature above a threshold temperature of 12°C.

[0056] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the reversible thermochromic formulation comprises reversible thermochromic pigments, an acrylic binder, and an IPA solvent matrix.

[0057] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, thermal paper for environmental exposure is prepared by a process comprising the steps of coating the thermal paper with at least one layer of a thick suspension of semi-reversible thermochromic ink. This at least one layer has a thickness of 1.5 mil when wet. Furthermore, the thick suspension of semi-reversible thermochromic ink is configured to change color state from black to colorless above a threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C.

[0058] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of imaging thermal paper with a dataform through at least one layer of a semi-reversible thermochromic ink to create the environmental exposure dataform. The semi-reversible thermochromic ink is configured to change color state from black to colorless above a threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C. The imaging process is not affected by at least one layer of the semi-reversible thermochromic ink.

[0059] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, said at least one layer of the semi-reversible thermochromic ink is applied as a coating to the thermal paper in the form of a thick suspension of semi-reversible thermochromic ink. Said at least one layer has a thickness of 1.5 mil when wet.

[0060] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, thermal paper for environmental exposure is prepared by a process comprising the steps of coating the thermal paper with at least one layer of a thick suspension of irreversible thermochromic ink. Said at least one layer has a thickness of 1.5 mil when wet, and the thick suspension of irreversible thermochromic ink is configured to change color state from colorless to black above a threshold temperature of 65°C.

[0061] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of imaging thermal paper with a dataform through at least one layer of an irreversible thermochromic ink to create the environmental exposure dataform. The irreversible thermochromic ink is configured to change the color state from colorless to black above a threshold temperature of 65°C. The imaging process is not affected by at least one layer of the irreversible thermochromic ink.

[0062] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, said at least one layer of irreversible thermochromic ink is applied as a coating to the thermal paper in the form of a thick suspension of irreversible thermochromic ink. Said at least one layer has a thickness of 1.5 mil when wet.

[0063] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, thermal paper for environmental exposure is prepared by a process comprising the steps of coating the thermal paper with at least one layer of a thick suspension of irreversible thermochromic ink. The layer has a thickness of 1.5 mil when wet, and the thick suspension of irreversible thermochromic ink is configured to change color state from colorless to magenta above a threshold temperature of 85°C.

[0064] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of imaging thermal paper with a dataform through at least one layer of an irreversible thermochromic ink to create the environmental exposure dataform. The irreversible thermochromic ink is configured to change color state from colorless to magenta above a threshold temperature of 85°C. The imaging process is not affected by at least one layer of the irreversible thermochromic ink.

[0065] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, said at least one layer of irreversible thermochromic ink is applied as a coating to the thermal paper in the form of a thick suspension of irreversible thermochromic ink. Said at least one layer has a thickness of 1.5 mil when wet.

[0066] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a thermal paper for environmental exposure is prepared by a process comprising the steps of coating the thermal paper with a layer of an SCC emulsion. The layer has a thickness of 1.5 mils when wet, and the SCC emulsion is configured to change color state from opaque white to colorless in response to exposure to a temperature above a threshold temperature of 40°C.

[0067] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal paper is printed by submersion in black before being coated with the SCC emulsion layer.

[0068] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, an environmental exposure dataform is prepared by a process comprising the steps of imaging thermal paper with a dataform through a layer of an SCC emulsion to create the environmental exposure dataform. The SCC emulsion is configured to change color state from opaque white to colorless in response to exposure to a temperature above a threshold temperature of 40°C. Furthermore, the imaging process is not affected by the SCC emulsion layer.

[0069] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the SCC emulsion is applied as a coating on the thermal paper to form the layer, and the layer has a thickness of 1.5 mil when wet.

[0070] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a direct thermal printer material, which includes an environmental exposure indicator material, also includes a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead. The thermal paper substrate has an imaging temperature and is capable of changing color when heated by the thermal printhead heated to or above the printing temperature. The direct thermal printer material also includes an environmental exposure indicator disposed on the thermal paper substrate.The temperature exposure indicator includes the environmental exposure indicator material, which is configured to change color state in response to temperature exposure above a predetermined threshold temperature, which is below the printing temperature.

[0071] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is a dye encapsulated in a matrix.

[0072] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0073] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation, (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength, and (h) an indicator material configured to change color state in response to exposure to moisture.

[0074] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material is (a), and the direct thermal printer material is configured to image a form of data, preferably a barcode, on the direct thermal printer material at a printing temperature above the threshold temperature without the environmental exposure indicator material changing color state.

[0075] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material is (a), and the environmental exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range selected from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0076] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0077] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0078] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0079] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head has a heated heat transfer temperature that is in the selected range in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0080] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head is configured to heat at least a portion of the thermal printer material direct to a heated heat transfer temperature which is in the range chosen in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C.

[0081] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetyl, an alkane, a wax, an ester, or combinations thereof.

[0082] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

[0083] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure has a particle size between 400 nm and 600 nm.

[0084] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the environmental exposure indicator material has a concentration, in a layer applied to the direct thermal printer material, in the selected range within the group consisting of approximately 10 to 60% w / w, approximately 20 to 60% w / w, approximately 25 to 60% w / w, approximately 30 to 60% w / w, approximately 35 to 60% w / w, approximately 40 to 60% w / w, approximately 30 to 60% w / w, approximately 30 to 55% w / w, approximately 30 to 50% w / w, approximately 30 to 45% w / w, approximately 40 to 55% w / w, approximately 40 to 50% w / w, and approximately 45 to 50% in weight / weight.

[0085] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is (c) and the second lower temperature threshold is in the range selected from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C.

[0086] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is disposed on the thermal paper substrate in the form of a thick ink suspension.

[0087] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet.

[0088] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from black to colorless above the threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C.

[0089] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is disposed on the thermal paper substrate in the form of a thick ink suspension.

[0090] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet.

[0091] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from colorless to black above the threshold temperature of 65°C.

[0092] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thick ink suspension is configured to change color state from colorless to magenta above the threshold temperature of 85°C.

[0093] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for environmental exposure is disposed on the thermal paper substrate in the form of an SCC emulsion.

[0094] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the SCC emulsion is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet.

[0095] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the SCC emulsion is configured to change color state from opaque white to colorless above the threshold temperature of 40°C.

[0096] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a thermal transfer ribbon comprises a support substrate, a temperature-threshold indicator material configured to change color state in response to exposure to a temperature above or below a threshold temperature, and a bonding layer. The bonding layer is positioned to couple the temperature-exposure indicator material to the support substrate and is configured to release the temperature-exposure indicator material onto a printable substrate when heated by a print head. Furthermore, the bonding layer has a melting temperature higher than the threshold temperature and has a stronger adhesion to the printable substrate than the bonding layer has to the support substrate.

[0097] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal transfer tape further comprises an anti-stick coating coupling the bonding layer to the support substrate.

[0098] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the non-stick coating is a heat-sensitive wax.

[0099] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature threshold exposure indicator material is selected from the group consisting of (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0100] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature threshold exposure indicator material is (a), and the temperature threshold exposure indicator material is configured to be applied to the printing substrate when the bonding layer has melted through the print head having a printing temperature above the melting temperature without the temperature threshold exposure indicator material changing color state.

[0101] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold is (a), and the indicator material for exposure to a temperature threshold is configured to change color state in response to exposure to the temperature above the threshold temperature for a period that is in the range chosen from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0102] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof.

[0103] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises an adhesive that is solvent-based, aqueous emulsion-based, or water-soluble.

[0104] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A.

[0105] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive has a melting temperature that is in the selected range in the group consisting of approximately 50 to 110°C, approximately 60 to 110°C, approximately 70 to 110°C, approximately 80 to 110°C, approximately 90 to 110°C, approximately 100 to 110°C, approximately 50 to 100°C, approximately 60 to 100°C, approximately 70 to 100°C, approximately 80 to 100°C, approximately 90 to 100°C, approximately 70 to 90°C, and approximately 80 to 90°C.

[0106] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0107] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0108] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0109] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head has a heated heat transfer temperature that is in the selected range in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0110] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head is configured to heat at least a portion of the thermal transfer ribbon to a heated thermal transfer temperature that is in the selected range within the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0111] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature threshold exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetyl, an alkane, a wax, an ester, or combinations thereof.

[0112] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

[0113] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold has a particle size between 400 nm and 600 nm.

[0114] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold has a concentration, in the bonding layer, in the selected range within the group consisting of approximately 10 to 60 wt%, approximately 20 to 60 wt%, approximately 25 to 60 wt%, approximately 30 to 60 wt%, approximately 35 to 60 wt%, approximately 40 to 60 wt%, approximately 30 to 60 wt%, approximately 30 to 55 wt%, approximately 30 to 50 wt%, approximately 30 to 45 wt%, approximately 40 to 55 wt%, approximately 40 to 50 wt%, and approximately 45 to 50 wt%. weight / weight.

[0115] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the substrate has a thickness of about 4 microns to about 6 microns.

[0116] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer has a thickness of about 2 microns to about 50 microns.

[0117] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold is (c), and the second lower temperature threshold is in the range selected from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C.

[0118] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer includes at least one additive configured to increase the thermal capacity of the bonding layer.

[0119] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester, and triacetin.

[0120] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold is (a) and does not change color state when released onto the printable medium.

[0121] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, a portion of the bonding layer is configured to release itself from the support substrate onto the printable substrate where the portion is heated by a heating element of the print head.

[0122] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold is configured to change color state from black to colorless in response to exposure to a temperature above the threshold temperature of 35°C.

[0123] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer is formed of an acrylic binder and an IPA solvent matrix.

[0124] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the support substrate is a blank thermal transfer tape.

[0125] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to a temperature threshold is configured to change color state from blue to colorless in response to exposure to a temperature above the threshold temperature of 12°C.

[0126] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer is formed of an acrylic binder and an IPA solvent matrix.

[0127] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the support substrate is a blank thermal transfer tape.

[0128] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a direct thermal label includes a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead. The thermal paper substrate has a printing temperature and is capable of changing color when heated by the thermal printhead heated to or above the printing temperature. The direct thermal label also includes a temperature exposure indicator disposed on the thermal paper substrate. The temperature exposure indicator includes the temperature exposure indicator material, which is configured to change color state in response to exposure to a temperature above a predetermined threshold temperature, which is below the printing temperature. Furthermore, the direct thermal label includes an image data form on the thermal paper substrate at or above the printing temperature without the temperature-exposure indicator material changing color state.

[0129] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is a dye encapsulated in a matrix.

[0130] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0131] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation, (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength, and (h) an indicator material configured to change color state in response to exposure to moisture.

[0132] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator is configured to reveal a barcode symbol in response to temperature exposure above the predetermined threshold temperature.

[0133] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator for temperature exposure is configured to hide the barcode symbol in response to temperature exposure below the predetermined threshold temperature.

[0134] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range chosen from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0135] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0136] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0137] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0138] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a label is configured to indicate exposure to a temperature above a threshold temperature. The label comprises a substrate with a first face and a second face. The first face includes a printable area and an irreversible thermochromic indicator material configured to change color state in response to exposure to a temperature above the threshold temperature. The label also includes an adhesive layer adjacent to the second face and a coating layer adjacent to the first face. The indicator material is located between the coating layer and the substrate.

[0139] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the printable area comprises a direct thermochromic material.

[0140] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the coating layer is a resin of a thermal transfer ribbon.

[0141] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the coating layer is a thermally printed overlayer.

[0142] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the coating is a varnish.

[0143] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the printable area includes the irreversible thermochromic indicator material.

[0144] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a method for manufacturing a thermal transfer ribbon includes providing a support substrate, providing a temperature indicator material configured to change color state in response to temperature exposure above a threshold temperature, and coupling the temperature indicator material to the support substrate by a bonding layer. The bonding layer is configured to release the temperature indicator material onto a printable substrate when heated by a print head. The bonding layer has a melting temperature above the threshold temperature.

[0145] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal transfer ribbon is configured such that, when the thermal transfer ribbon is heated by the print head of a thermal printer on one face of the support substrate opposite the temperature exposure indicator material, so as to melt the bonding layer, the temperature exposure indicator material is released from the support substrate and applied to the printable substrate.

[0146] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the method further comprises providing a non-stick coating that couples the bonding layer to the support substrate, and coating the support substrate with the non-stick coating before coating the support tape with the bonding layer. The non-stick coating is configured to couple the bonding layer to the support tape.

[0147] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the non-stick coating is a heat-sensitive wax.

[0148] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0149] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is (a), and the temperature exposure indicator material is configured to be applied to the printing substrate when the bonding layer is melted by the print head having a printing temperature above the melting temperature without the temperature exposure indicator material changing color state.

[0150] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is (a), and the temperature exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range selected from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0151] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof.

[0152] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises an adhesive that is solvent-based, aqueous emulsion-based, or water-soluble.

[0153] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A.

[0154] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive has a melting temperature that is in the selected range within the group consisting of approximately 50 to 110°C, approximately 60 to 110°C, approximately 70 to 110°C, approximately 80 to 110°C, approximately 90 to 110°C, approximately 100 to 110°C, approximately 50 to 100°C, approximately 60 to 100°C, approximately 70 to 100°C, approximately 80 to 100°C, approximately 90 to 100°C, approximately 70 to 90°C, and approximately 80 to 90°C.

[0155] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the process further comprises dissolving the adhesive and the temperature-exposure indicator material in a solvent to form a solution, applying the solution to the support substrate, and drying the solution to form the bonding layer.

[0156] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0157] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0158] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0159] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head has a heated heat transfer temperature that is in the selected range within the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0160] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head is configured to heat at least a portion of the heat transfer ribbon to a heated heat transfer temperature that is within the selected range in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0161] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester, or combinations thereof.

[0162] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

[0163] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a particle size between 400nm and 600nm.

[0164] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a concentration, in the bonding layer, in the range selected from the group consisting of about 10 to 60 wt%, about 20 to 60 wt%, about 25 to 60 wt%, about 30 to 60 wt%, about 35 to 60 wt%, about 40 to 60 wt%, about 30 to 60 wt%, about 30 to 55 wt%, about 30 to 50 wt%, about 30 to 45 wt%, about 40 to 55 wt%, about 40 to 50 wt% and about 45 to 50 wt%.

[0165] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the substrate has a thickness of about 4 microns to about 6 microns.

[0166] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer has a thickness of about 2 microns to about 50 microns.

[0167] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for temperature exposure is (c) and the second lower temperature threshold is in the range selected from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C.

[0168] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer includes at least one additive configured to increase the thermal capacity of the bonding layer.

[0169] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester, and triacetin.

[0170] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a method for use with a thermal transfer ribbon having a support substrate and a temperature indicator material coupled to the substrate via a bonding layer includes receiving a trace of a temperature indicator. The temperature indicator is to be formed by the temperature indicator material of the bonding layer, and the temperature indicator material is configured to change color state in response to exposure to a temperature above or below a predetermined threshold temperature.The process also includes heating the bonding layer with a print head to a temperature at or above the bonding layer's melting temperature, causing the bonding layer to transfer from the thermal transfer ribbon to a printing surface to print the temperature indicator according to the received pattern. The bonding layer's melting temperature is above the threshold temperature.

[0171] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal transfer tape further comprises an anti-stick coating coupling the bonding layer to the support substrate.

[0172] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the non-stick coating is a heat-sensitive wax.

[0173] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to temperature is chosen from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature;(c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0174] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for exposure to temperature is (a), and the transfer of the bonding layer from the support substrate to the printing surface, by the print head, is carried out without the irreversible thermochromic indicator material changing color state.

[0175] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is (a), and the temperature exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range selected from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0176] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the process further includes printing a barcode symbol on the printing surface.

[0177] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the printing surface is a product surface.

[0178] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the method further includes aligning the temperature indicator trace with a designated space on the printing surface.

[0179] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the process further includes receiving a label that includes a computer-readable index encoding a data code word applied to it, the printing surface being the label. In addition, the method includes locating the computer-readable index, and determining a printing position for the temperature exposure indicator based on a position of the computer-readable index or the data code word encoded in the computer-readable index.

[0180] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof.

[0181] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises an adhesive that is solvent-based, aqueous emulsion-based, or water-soluble.

[0182] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A.

[0183] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the adhesive has a melting temperature that is in the selected range within the group consisting of approximately 50 to 110°C, approximately 60 to 110°C, approximately 70 to 110°C, approximately 80 to 110°C, approximately 90 to 110°C, approximately 100 to 110°C, approximately 50 to 100°C, approximately 60 to 100°C, approximately 70 to 100°C, approximately 80 to 100°C, approximately 90 to 100°C, approximately 70 to 90°C, and approximately 80 to 90°C.

[0184] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is in the selected range within the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0185] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C.

[0186] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the threshold temperature is 40°C.

[0187] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head has a heated heat transfer temperature that is in the selected range within the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0188] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the print head is configured to heat at least a portion of the thermal transfer ribbon to a heated thermal transfer temperature that is in the selected range within the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0189] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester, or combinations thereof.

[0190] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

[0191] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a particle size between 400 nm and 600 nm.

[0192] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material has a concentration, in the bonding layer, within the selected range of approximately 10 to 60 wt%, approximately 20 to 60% by weight, approximately 25 to 60% by weight, approximately 30 to 60% by weight, approximately 35 to 60% by weight, approximately 40 to 60% by weight, approximately 30 to 60% by weight, approximately 30 to 55% by weight, approximately 30 to 50% by weight, approximately 30 to 45% by weight, approximately 40 to 55% by weight, approximately 40 to 50% by weight, and approximately 45 to 50% by weight.

[0193] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the substrate has a thickness of about 4 microns to about 6 microns.

[0194] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer has a thickness of about 2 microns to about 50 microns.

[0195] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the indicator material for temperature exposure is (c), and the second lower temperature threshold is in the range selected from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C.

[0196] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer includes at least one additive configured to increase the thermal capacity of the bonding layer.

[0197] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester, and triacetin.

[0198] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a method for manufacturing a temperature-indicating printing material includes receiving a thermal paper material and applying a thermochromic temperature-indicating material to the thermal paper material. The thermochromic temperature-indicating material is configured to change color state in response to reaching a temperature lower than the printing temperature of the thermal paper material.

[0199] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the method further includes the application of a varnish or coating to the thermochromic temperature indicator material.

[0200] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal paper material is a direct thermal printing paper containing a thermochromic pigment configured to change color when the printing temperature is reached.

[0201] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the printing temperature is in the selected range within the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

[0202] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature for the temperature indicator material is in the selected range within the group consisting of approximately 20 to 50°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

[0203] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0204] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation, (g) an indicator material configured to change color state in response to exposure to light of a wavelength of predetermined wave, and (h) an indicator material configured to change color state in response to exposure to moisture.

[0205] Aspects of the object described herein may be useful individually or in combination with one or more other aspects described herein. In one aspect of this disclosure, a method for manufacturing a temperature exposure indicator includes receiving thermal paper material onto which a thermochromic temperature indicator has been applied. The thermochromic temperature indicator is configured to change color state above a threshold temperature. The method also includes printing on the thermal paper material using a direct thermal printing process through the thermochromic temperature indicator with a thermal printhead that causes portions of the thermal paper material to reach a printing temperature above the threshold temperature without triggering the color change of the thermochromic temperature indicator.

[0206] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the thermal paper material comprises a dye encapsulated in a matrix that is configured to change state when the printing temperature is reached.

[0207] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the temperature exposure indicator material is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature, (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature,and to maintain the changed color state until the temperature falls below a second lower temperature threshold, and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0208] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation, (g) an indicator material configured to change color state in response to exposure to light of a wavelength of predetermined wave, and (h) an indicator material configured to change color state in response to exposure to moisture.

[0209] In another aspect of this disclosure, which may be used in combination with any other aspect or combination of aspects listed herein, a machine-readable, non-transient medium stores code which, when executed by at least one processor, is configured to execute any of the preceding aspects listed herein.

[0210] Other disclosed features and advantages of the method and apparatus are described in the following Detailed Description and the Figures, and will become apparent therefrom. The features and advantages described herein are not exhaustive, and in particular, many additional features and advantages will become apparent to a person with ordinary technical competence from the figures and the description. Furthermore, it should be noted that the language used in the description has been chosen primarily for readability and educational purposes, and not to limit the scope of the invention. BRIEF DESCRIPTION OF THE FIGURES

[0211] [Fig. 1] The [Fig. 1] is a functional diagram of a thermal transfer ribbon by way of example, according to an exemplary embodiment of this disclosure.

[0212] [Fig.2A] [Fig.2B] [Fig.2C] Figures 2A, 2B and 2C are functional diagrams of heat transfer ribbons by way of example, according to an exemplary embodiment of this disclosure.

[0213] [Fig.3A] The [Fig.3A] is a functional diagram of a material for a direct thermal printer by way of example, according to an exemplary embodiment of this disclosure.

[0214] [Fig.3B] The [Fig.3B] is a functional diagram of a label by way of example, according to an exemplary embodiment of this disclosure.

[0215] [Fig.4] The [Fig.4] is a working diagram of an example printing process according to an example embodiment of this disclosure.

[0216] [Fig.5] The [Fig.5] is a functional diagram of a label by way of example, according to an exemplary embodiment of this disclosure.

[0217] [Fig.6A] [Fig.6B] [Fig.6C] Figures 6A, 6B and 6C are functional diagrams of a direct thermal label by way of example, according to an exemplary embodiment of this disclosure.

[0218] [Fig.7A] The [Fig.7A] is a flowchart illustrating an exemplary process for the manufacture of a thermal transfer ribbon, according to an exemplary embodiment of this disclosure.

[0219] [Fig.7B] The [Fig.7B] is a flowchart illustrating an exemplary method for applying a temperature indicator to a printing surface with a thermal transfer ribbon, according to an exemplary embodiment of this disclosure.

[0220] [Fig.7C] The [Fig.7C] is a flowchart illustrating an exemplary process for manufacturing a temperature-indicating printing material according to an exemplary embodiment of this disclosure.

[0221] [Fig.7D] The [Fig.7D] is a flowchart illustrating an exemplary process for manufacturing a temperature exposure indicator, according to an exemplary embodiment of this disclosure.

[0222] [Fig.7E] The [Fig.7E] is a flowchart illustrating an exemplary process for the manufacture of thermal paper for environmental exposure, according to an exemplary embodiment of this disclosure.

[0223] [Fig.7F] [Fig.7F] is a flowchart illustrating a process by way of example for the fabrication of a form of data for environmental exposure, according to an exemplary embodiment of this disclosure.

[0224] [Fig.7G] The [Fig.7G] is a flowchart illustrating an exemplary process for the manufacture of a thermal transfer tape for environmental exposure, according to an exemplary embodiment of this disclosure.

[0225] [Fig.8A] [Fig.8B] [Fig.8C] [Fig.8D] [Fig.8E] Figures 8A, 8B, 8C, 8D and 8E are tables of experimental results of embodiments as examples of this disclosure.

[0226] DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0227] Thermal transfer ribbons and a direct thermal printer material with an environmental exposure indicator material, such as a temperature exposure indicator material, are disclosed herein. Furthermore, techniques for manufacturing the thermal transfer ribbons and the direct thermal printer material, as well as techniques for printing environmental exposure indicators, such as temperature exposure indicators, with the thermal transfer ribbons or the direct thermal printer material, are disclosed.Previous applications involving thermal printing have not addressed the application of a temperature exposure indicator material, such as a rising temperature threshold exposure indicator material (also sometimes called a peak temperature exposure indicator) that changes color state in response to temperature exposure above or below a temperature threshold by the thermal printing process. for temperature monitoring. Instead, existing thermal printing processes often print static information that is not sensitive to environmental factors such as temperature, time, time-temperature product, freezing, nuclear radiation, toxic chemicals or the like.

[0228] The printing methods and materials disclosed herein describe thermal transfer ribbons and direct thermal media. For certain applications, information that varies from label to label, document to document, or batch of labels to batch, can be printed with a thermal printer, while information that is the same on each document can be pre-printed using flexographic or other methods before the label is loaded into the thermal printer. Thermal printers can be configured to print via thermal transfer printing when a thermal transfer ribbon is loaded and configured to print via direct thermal printing when a direct thermal media is loaded. Thermal printers may include a sensor to detect when a thermal transfer ribbon is loaded.Thermal transfer printers may include at least one first thermal printhead configured to transfer a first rendered bitmap onto a document and a second thermal printhead configured to transfer a second rendered bitmap onto the document. In other cases, thermal printers may be configured to print via dye sublimation printing when a ribbon with dye sublimation panels is loaded, and to print via thermal transfer printing when loaded with a ribbon with thermal transfer panels or with a thermal transfer ribbon.

[0229] Materials such as ink, dye, paint, toner, or wax can be used to color a surface to produce an image, text, graphic, or barcode symbol. As used here, a barcode symbol is a pattern readable by a data-encoding machine. The barcode symbol is a type of data form. Other types or examples of data forms include text, numbers, graphics, and so on. Text is a data form representing written language, numbers are data forms representing arithmetic values, and graphics are data forms representing images.

[0230] A barcode symbol can be composed of one or more barcode elements, which can be called barcode modules. An element or module is a set of contrasting patterns arranged on a substrate To facilitate data decoding by a barcode reader or scanner, a barcode element or module can describe both a "black" box and a "white" box, or a "light-absorbing" box and a "light-reflecting" box. In other examples, a barcode element or module can also describe a "light-emitting" element if luminescent materials are used. Some barcode symbols include one or more silent areas—a region surrounding a set of elements or modules that is free of contrasting markings—to allow the barcode reader to detect the barcode symbol in a captured image. Some barcode symbols include elements or modules, called search patterns, that provide a consistent pattern to enable the barcode reader to detect the barcode symbol in a captured image.

[0231] The procedure by which data is encoded in the barcode symbol, the arrangement of barcode elements or modules within the barcode symbol, and all requirements relating to the elements or modules and to the blank space are defined by a set of rules called barcode symbology. The data can be encoded into the contrasting patterns by software, such as a computer application or printer firmware.

[0232] Barcode symbols, which may generally be referred to herein as barcodes, may be displayed on a screen or marked on a substrate. Barcode elements or modules may be marked on a substrate in various ways. Black bars (rectangles, squares, circles, triangles, or other shapes are generally called bars, or elements, in a barcode) may be printed on a white or mirrored substrate to create the contrasting pattern of an element or module. Similarly, white patterns may be printed on a black or transparent substrate to create the contrasting pattern of an element or module. In both cases, a barcode reader would capture an image of the barcode by receiving the light reflected from the white parts of the element or module at a greater intensity than the light reflected from the black parts of the element or module.The contrasting intensity pattern of the captured image is then processed by the barcode reader to decode the data carried by the barcode. In some embodiments, a reflective or mirrored surface can provide the contrasting pattern. Barcode elements or modules can also be marked on a substrate by engraving or indenting a smooth surface; in this case, light is received at different intensities on a smooth surface compared to a textured surface.

[0233] Barcode symbols can be used in many industries to facilitate fast and accurate data entry. Using a barcode scanner Using barcode scanning, a nurse working in a healthcare facility can scan a first barcode printed on a patient's wristband to link it to an electronic medical record detailing a prescribed medication, and then scan a second barcode printed on a label affixed to a medication bottle to link it to drug information associated with a National Drug Code (NDC). The software can compare the prescribed medication with the drug information to confirm that the nurse is administering the correct medication, at the correct dose, and at the correct time, to the correct patient.While the nurse could perform the same comparison using a patient ID on a wristband, a handwritten prescription, the pharmacist's notes on a pillbox, and their watch, the barcode-based system offers greater accuracy and requires less attention from the nurse, freeing them up to provide personalized patient care.

[0234] In another application, a dockworker in the receiving area of ​​a large resort may receive hundreds of shipments containing food, alcoholic beverages, hotel supplies, merchandise, conference equipment, or furniture during a typical day. Using a barcode scanner, the dockworker can scan a barcode printed on packaging, shipping documents, a parcel label, or a pallet label to link it to an advance shipping notice in a site management database detailing the contents of each shipment and the area of ​​the resort that needs the received item. While all received items must eventually be moved, the information from the site management database can alert the dockworker to specific handling requirements.Live lobsters can be shipped to the kitchen, ice cream must remain frozen, fresh chicken should remain refrigerated but not frozen, expensive alcoholic beverages in fragile bottles can be safely stored in a locked warehouse before being distributed to bars, conference equipment can be shipped for an organization's event, while shampoo or hand sanitizer can probably wait a few hours before being delivered to housekeeping.While an experienced dockworker might prioritize each received item based on routing information on the package or pallet, the barcode-based system provides easy-to-understand guidance based on common situations in the resort, reducing handling, speeding up delivery truck turnaround time, accelerating delivery, reducing waste, and greatly decreasing concerns for chefs, bartenders, managers, and guests.

[0235] Documents containing barcodes can be printed on labels, tags, wristbands, packaging, and other substrates in many ways. Paper documents and wristbands can be printed on laser printers that load a drum with a rendered image, attract toner to the loaded image, apply this toner to a document or wristband shape, and then fuse the toner to the substrate using a heated roller.Thermal printing can be particularly well suited to barcode printing because commercially available barcode label printers are configured to render a barcode and print it onto a label, tag, wristband, plastic card, RFID smart tag or similar substrates at high speed while maintaining accurate outline contrast between dark and light elements of the barcode, to handle label or wristband strips with excellent dimensional tolerance and to connect easily to various computer systems and networks.

[0236] To print labels or other documents, thermal printers can use a thermal printhead comprising a row of addressable heating elements to heat a thermal substrate. The elements are small compared to the image to be printed; for example, 8, 12, or 24 elements per mm, and other resolutions, are commercially available. This differs from thermal inkjet printers, which use addressable heating elements to heat ink or wax that is dripped or ejected onto a document or other printable substrate.

[0237] Embodiments described in this disclosure provide a unique way of printing coded sensor information (either individually or with pre-printed static data) onto a printable medium or substrate. The pre-printed data and coded sensor information can be combined in a single step, or the coded sensor information can be dynamically added to the pre-printed data in a secondary step depending on the actual intended use of the sensor. Materials Temperature Indicators

[0238] As used here, the terms "threshold" and "threshold temperature" have their normal meaning in the art and include a temperature, usually a temperature above 0°C (although temperatures below 0°C are also considered), that can cause damage or harm to a product, such as food or a vaccine, which generally requires refrigeration to prevent spoilage or maintain efficacy over extended periods. The term "threshold temperature" can therefore refer to any predetermined temperature that is above a desired storage temperature for a perishable product.

[0239] The term "melting point" is used here to denote the lowest temperature at which a threshold indicator dispersion, or a deep eutectic solvent, exhibits a detectable melting-induced change in appearance that can be unmistakably determined by observation, visual or otherwise. The observable change may be a change from opaque to clear, the disappearance of ice crystals, brightening, a change in color, a change in electrical conductivity, etc.

[0240] The environmental or temperature indicators described herein can generally be called dynamic indicators. For example, indicator materials for environmental exposure may include one or more dynamic materials. Dynamic materials may be capable of changing their state, for example, their optical properties such as color, in response to an external event or condition. For example, the dynamic indicator may be an environmental indicator or sensor, a medical indicator or sensor, etc.Examples of environmental sensors include temperature monitors, measuring either cumulative heat exposure or exceeding one or more high or low temperature threshold values; time monitors, measuring the time-temperature product, and monitoring exposure to nuclear radiation; and gas or humidity exposure monitors, each measuring exceeding a cumulative exposure threshold or an instantaneous threshold value. Examples of medical sensors include patient recording thermometers, threshold tests measuring levels of biological toxins such as aflatoxin or botulinum toxin, and colorimetric immunoassays for detecting the presence of biological agents such as prions or organisms such as infectious bacteria. Thermal Transfer Ribbons.

[0241] Various thermal printing technologies can be used to print data shapes, such as barcode symbols. A thermal transfer printer uses a thermal transfer ribbon as the thermal medium. The thermal transfer ribbon can be coated with a binder, for example, a wax or fusible resin, and an ink. The thermal transfer ribbon is aligned with the label strip and is fed past the thermal printhead, which presses the ribbon onto the printable medium. The thermal printhead receives data from a rendered bitmap and heats specific heating elements in the addressable heating element array according to the data. The heat from the heating elements melts the ribbon binder adjacent to the heating element, causing the ink to be transferred onto the printable medium.In this disclosure, thermal transfer ribbons may be provided which include . particular types of special inks, for example, inks that change color or appearance in response to temperature.

[0242] The printhead heating elements that are not heated do not cause the wax or resin of the adjacent ribbon to melt, so no ink is transferred to the substrate in these areas. This allows the thermal printhead to print a single row of dots onto the substrate: this could be a solid line, a blank line, or any row of a rendered image, which may include a barcode, text, or graphics. As the substrate and ribbon pass past the thermal printhead, the printed line cools, causing the printed image to permanently adhere to the substrate. The process is repeated for subsequent lines until the rendered image is printed onto the substrate.The resulting document may include the indicator material for environmental exposure, the wax or resin binder, or sometimes other materials that have been applied as a coating to the thermal transfer ribbon.

[0243] Because the printhead heating elements are small and the support web is moved at high speed, most of the heat from the printhead is consumed to melt the wax or resin binder, thereby preventing most of the heat from being conducted to other parts of the ribbon (e.g., through the environmental exposure indicator material) and to the printable support. Thus, typically, only a small amount of heat is conducted to other parts of the ribbon (e.g., through the environmental exposure indicator material), which advantageously prevents the printing process from affecting the color state of the environmental exposure indicator material.Furthermore, this makes thermal transfer printing well-suited for printing documents on heat-sensitive synthetic printable substrates or materials, and for labels with heat-sensitive adhesives. Printable substrates can be chosen to provide a contrasting color to the ribbon; for example, white or colored labels are typically used with black ribbons, and black or transparent labels are typically used with white ribbons.

[0244] Various types of thermal transfer ribbons can be manufactured. A thermal transfer ribbon may include a backing substrate such as a plastic film. On one side of the backing substrate, a backing material is applied first, which reduces friction and / or improves heat transfer between the thermal printhead and the thermal transfer ribbon. On the opposite side of the backing substrate, a binder, possibly a wax or resin, is applied as a second coating, followed by an ink or other colored material, and finally, a protective layer to prevent the ink from spreading. smearing or peeling from the ribbon before it has been heated by the thermal printhead. For some ribbons, the third coating layer may include patterns or inks of different colors. During printing, the thermal printhead is positioned on the first side of the substrate, with the second side of the substrate facing the bonding layer, the ink layer, and the printable media. For some ribbons, various coatings may be combined or omitted.

[0245] Figure 1 illustrates an exemplary embodiment of a thermal transfer ribbon 100. The thermal transfer ribbon 100 is used to transfer an indicator material for environmental exposure, such as an ink, from a support substrate 104 to a printing substrate (not shown). In one example, the support substrate 104 may be a plastic film. A thermal printhead uses heat to activate the adhesion of the bonding layer 106 to the printing substrate such that the bonding layer 106 detaches from the support substrate 104 (e.g., the substrate or the ribbon) and remains attached to the printing substrate. In one example, the thermal transfer ribbons are adapted such that, upon application of heat by a thermal printhead, the bonding layer 106 fractures at the edge of a pattern, and the thermal ribbon advantageously minimizes or eliminates tearing beyond the pattern.As illustrated in [Fig. 1], a thermal transfer ribbon 100 comprises a support substrate 104 (for example, polyester) and a bonding layer 106 which comprises the indicator material for exposure to the environment, such as a temperature exposure indicator material.

[0246] The environmental exposure indicator material is configured to change its color state in response to environmental exposure above or below a threshold exposure level. An example of an environmental exposure indicator material is a rising temperature threshold exposure indicator material (also sometimes called a peak temperature exposure indicator) that is configured to change its color state in response to temperature exposure above or below a temperature threshold. Throughout this disclosure, when the expression "temperature exposure indicator" is used (without any other qualifier, such as "cumulative" or "falling"), it refers to a rising temperature threshold exposure indicator.

[0247] Cumulative exposure indicators are configured to change state (for example, color state) in response to cumulative exposure to an environmental condition. For example, a cumulative temperature indicator can measure either cumulative heat exposure or exceeding one or more high or low temperature threshold values, a time, or a time-product. temperature. Other indicators for cumulative exposure as examples may include monitors of exposure to nuclear radiation, monitors of exposure to gases or humidity, each passing above a cumulative exposure threshold.

[0248] Upward and downward indicators and indicator compositions may use deep eutectic solvents, that is, a deep eutectic solvent (DES) having a melting point that is distinct from its freezing point, such that, upon exposure to a desired low temperature, the DES freezes in an observable manner, which may be a visual change in appearance (e.g., scattering light) or another observable change, such as electrical conductivity. Alternatively, upon exposure to a desired threshold temperature, some DES may melt in an observable manner, which may be a visual change in appearance (e.g., becoming transparent or translucent) or another observable change, such as electrical conductivity.Due to the difference between melting temperature and freezing temperature, DES and DES-based indicators may be able to maintain the observable change even when subsequently exposed to or returned to a temperature within the desired storage range.

[0249] A number of different DESs may be suitable for use in freezing or threshold indicators. For example, DESs may be obtained with a suitable organic salt such as choline chloride and a hydrogen bond donor such as urea, substituted ureas, glycerol, glycols—such as ethylene glycol—etc., or a metal salt hydrate. In some embodiments, the components are mixed together, heated, and stirred to give a liquid whose freezing point is much lower than that of the individual components, hence the term deep eutectic. The actual freezing point may depend on the ratios between the two (or possibly more than two) components. There is a particular ratio at which the freezing point will be a minimum. Deep eutectic indicator materials by way of example are described in U.S. Publication No. 2019 / 0285482.

[0250] In this disclosure, a rising temperature indicator may include threshold temperature indicators that can be used to determine whether a perishable product has been exposed to a temperature above an acceptable temperature or an acceptable temperature range. Embodiments of a threshold indicator according to this disclosure may exhibit an unmistakable heat-induced change in appearance within a relatively short period of time, for example, within one hour of exposure to the temperature of beginning of melting, or at a higher temperature. The indicators can produce an unmistakable, heat-induced change in appearance, consistently and reliably, from one sample to the next, after exposure for shorter periods of time, for example, 15 minutes, or 5 minutes, or another period below about 30 minutes.

[0251] In this disclosure, a descending temperature indicator may include freezing indicators that can be used to determine whether a perishable product has been exposed to a temperature below an acceptable temperature or within an acceptable temperature range. Embodiments of a freezing indicator according to this disclosure may exhibit an unmistakable freezing-induced change in appearance within a relatively short period of time, for example, within one hour of exposure to the freezing-start temperature, or a temperature lower. The indicators may produce an unmistakable freezing-induced change in appearance, consistently and reliably, from one sample to the next, after exposure for shorter periods, for example, 15 minutes, or 5 minutes, or another period below approximately 30 minutes.

[0252] In this disclosure, a temperature indicator may include a thawing indicator, which may have temperature ranges from 0°C to -80°C. Thawing indicators by way of example are materials that are tuned to change state at or slightly below the point at which a product or material, which is normally distributed frozen, will thaw. Examples are described in U.S. Patent No. 7,624,698, U.S. Patent No. 7,891,310, and U.S. Patent No. 8,128,872. Thawing indicators may include some of the semi-reversible thermochromic indicator materials described herein, which are configured to change color state in response to a temperature above a threshold temperature and to maintain the changed color state until the temperature falls below a second, lower temperature threshold.For example, semi-reversible thermochromic ink may be blue at room temperature, change from blue to colorless at temperatures above 50°C, and revert to blue when exposed to temperatures below 0°C. Thawing indicators may utilize liquid crystal technology; for instance, LCR Hallcrest offers a liquid crystal ink with a temperature range of 0°C to 90°C. Another commercially available thawing indicator is the StaFreez® from Biosynergy, an irreversible freeze-thaw indicator that monitors the status of frozen (biomedical) materials during shipping and storage. StaFreez® indicators are activated upon use. The indicator is heated to 40-50°C and immediately applied to the frozen material (-20°C or below). A light blue "F" will appear, indicating that the material is frozen. When the frozen material is warmed above -20°C, the color of the "F" will gradually change from light blue to blue-gray, then to gray, and finally to black when the frozen material reaches 0°C. If the thawed material is refrozen, the "F" will remain black, indicating that the material has thawed at some point in its history. Some of the semi-irreversible indicators (e.g., memory indicators) discussed here can be described as thawing indicators.

[0253] The bonding layer 106 is positioned to couple the temperature-exposure indicator material to the support substrate 104. The bonding layer 106 is also configured to release the environmental-exposure indicator material (e.g., the temperature-exposure indicator material) onto a printable substrate when heated by a print head. In one example, the bonding layer 106 may have a melting temperature above the threshold temperature of the temperature-exposure indicator material, but the bonding layer 106, or a portion thereof, may be transferable onto the printable substrate without the temperature-exposure indicator material changing its color state.In one example, the temperature exposure indicator can change color state after a temperature exposure of at least ten seconds, which is longer than a typical printing operation, thus preventing a color state change during the printing process. For example, the temperature exposure indicator material can be configured to change color state in response to temperature exposure above the threshold temperature for a period that is within the range chosen from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

[0254] In some examples, the activation temperature of the temperature exposure indicator can be determined by the indicator's melting point. For instance, when the temperature exposure indicator is exposed to an ambient temperature above its activation temperature, the indicator material may liquefy. Once liquefied, the indicator material may diffuse, resulting in a change in the indicator's appearance. In other examples, the temperature indicator (such as a peak exposure indicator) may comprise a first reagent, a second reagent, and a fusible solid. The first reagent may be chemically co-reactive with the second reagent to provide a color change, and the fusible solid may physically separate the first reagent from the second reagent.The color-changing chemical reaction can be induced in response to a peak of exposure to ambient heat, which can be a peak that exceeds the point of . Melting of the fusible solid. For example, the melting of the fusible solid caused by the peak of exposure to ambient heat can bring the first reactant into contact with the second reactant. Such a dual-function heat indicator can indicate cumulative exposure to ambient heat and / or peak exposure to ambient heat by changing color.

[0255] As used here, the terms "melting temperature" or "melting point" refer to the temperature at which a material exhibits a unit peak heat absorption per degree Celsius, as determined by differential scanning calorimetry. Above its melting temperature, the transport material may exhibit liquid properties and may move, for example, flow or diffuse.

[0256] In another example, the ribbon 100 can be formulated and constructed such that most of the heat from the printhead can be consumed to melt the wax or resin binder, thus preventing heat from being conducted through other parts of the ribbon (e.g., through the indicator material for exposure to the environment). This can occur for any one of at least several reasons: (1) the mass of the binder serves to insulate the ink, thus preventing heat transfer to the ink, (2) the indicator can be insulated by other materials, for example, a matrix in which the temperature phase-change material is incorporated, (3) the mass of the binder is much smaller than the mass of the indicator,so that the amount of heat required to melt or otherwise change the state of the indicator is much greater than the amount of heat required to melt or otherwise release the binder, (4) where the indicator changes state by melting, the latent heat of fusion of the binder may be much lower than the latent heat of fusion of the indicator, so that the amount of exposure to the critical temperature required to cause the release of the binder is much lower than the amount of heat required to change the state of the indicator.

[0257] The bonding layer 106, or a portion thereof, transfers to the printable substrate because, when heated, the bonding layer 106 exhibits stronger adhesion (e.g., higher adhesion) to the printable substrate than the bonding layer's adhesion to the substrate. For example, the binder may be physically bonded to the ribbon by being incorporated into the ribbon's physical matrix, and these bonds may break when the binder melts; the binder may have reduced adhesion to the ribbon when it changes state; and the binder or additional additives to the ribbon may tend to increase the ink's adhesion to the printable substrate.

[0258] Figures 2A, 2B and 2C illustrate different embodiments of thermal transfer ribbons 100b, 100c and 100d. As illustrated in [Fig. 2A], a thermal transfer ribbon 100b comprises a backing, a backing substrate 104 (e.g., polyester), and a bonding layer 106. The bonding layer 106 may include one or more sublayers such as a non-stick coating or non-stick layer 109, an indicator material layer 108, and an adhesive layer 110. [Fig. 2B] illustrates another example of a thermal transfer ribbon 100c that comprises a backing 102, a backing substrate 104 (e.g., polyester), a non-stick layer 109, and a bonding layer 106. [Fig. 2C] illustrates a cold foil-type transfer ribbon 100d that comprises a backing substrate 104, such as a non-stick polyester, and an indicator material layer 108.The indicator material layer 108 can be a non-adhesive layer.

[0259] Examples of support substrates 104 include polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof. The support substrate 104 may have a non-adhesive surface 122 on the printhead side and a non-adhesive surface 119 between the support substrate 104 and the indicator material layer 108. The support substrate 104 (for example, non-adhesive polyester) may have a thickness of approximately 5 to 12 micrometers, preferably between 5 and 6 micrometers, and more preferably 4.8 micrometers. The indicator material layer 108 may have a thickness of approximately 2 to 50 micrometers, preferably 2 to 4 micrometers.

[0260] Thermal transfer ribbons 100a, 100b, 100c, and 100d (hereinafter generally referred to as thermal transfer ribbon 100) may include additives that advantageously improve dispersion, coating, and / or printing. Depending on the application, the thermal transfer ribbon 100 may have a size and shape such that the consumption of environmental exposure indicator material, such as temperature exposure indicator material, is minimized during printing. For example, the thermal transfer ribbon 100 may be selectively coated with environmental exposure indicator material, or the width of the thermal transfer ribbon 100 may be changed to reduce the amount of environmental exposure indicator material left on a used thermal transfer ribbon 100.

[0261] The backing 102 may be a heat-resistant layer comprising one or more heat-resistant binders and one or more sliding agents. The backing 102 is suitable for providing sufficient heat resistance to protect the support substrate 104, which may also be called a film or support, and prevent sticking between the print head and the ribbon 100. The back coating 102 can also be suitable for improving heat transfer between the thermal print head and the thermal transfer ribbon 100. In addition, the back coating 102 is suitable for providing sufficient sliding characteristics to the thermal transfer ribbon 100. In one example, the back coating 102 can have a thickness of approximately 0.5 micrometers.

[0262] The backing 102 can be prepared as a solution or dispersion in a solvent or in water and applied to the support substrate 104 as a liquid using standard printing or coating techniques followed by drying and / or curing. In one example, the backing 102 can be prepared by adding one or more sliding agents, one or more surfactants, one or more inorganic particles, one or more organic or similar particles to a binding resin.Examples of resins include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrocellulose or the like; vinyl-type resins such as polyvinyl alcohol, poly(vinyl acetate), polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, acrylic resin, polyacrylamide, acrylonitrile-styrene copolymer or the like; polyester resin; polyurethane resin; silicone-modified urethane resin or fluorine-modified urethane resin, or the like.

[0263] In other examples, the back coating 102 may be unnecessary if the support substrate 104 provides sufficient heat resistance and / or sliding properties for the thermal transfer ribbon 100. However, when using a support substrate 104 with low heat resistance, it may be preferable to apply a heat-resistant layer or a heat-resistant back coating 102 to a back surface of the thermal transfer ribbon 100. Since the back surface is in contact with the thermal printhead, the back coating 102 advantageously improves a sliding property of the thermal printhead and prevents the thermal printhead from sticking to the thermal ribbon 100.

[0264] In one example, the support substrate 104 is a polymer film, such as polyester. The polyester may be heat-stabilized. In digital thermal transfer printing applications, the thickness of the support substrate 104 may be between 4.5 and 5.7 micrometers. Other support substrate thicknesses may be used, for example, a polyester 12, 17, or 24 micrometers thick, particularly if the printing is performed by step-and-repeat or rotary hot stamping.

[0265] The thermal transfer ribbon 100 has anti-stick properties to ensure proper transfer of the material for environmental exposure or the respective layer containing the material for environmental exposure from the image-side surface 112 of the film or ribbon 100 (for example, the side of the ribbon 100 facing the printable substrate). For example, the transfer ribbon 100 may include an anti-stick coating, an anti-stick layer 109, or an anti-stick surface 119 (see [Fig. 2C]) such that the bond between the support substrate 104 and the bonding layer 106 is sufficiently weak to separate when subjected to heating by a thermal printhead. In one example, the anti-stick coating or the anti-stick layer 109 may be a heat-sensitive wax that couples the bonding layer 106 or indicator material layer 108 to the support substrate 104.Specifically, the anti-adhesive layer 109 must maintain the bonding layer 106 or other corresponding layer encapsulating the material for exposure to the environment on the support substrate 104 in such a way that it is not removed from any actions or activities on the ribbon before image generation. For example, the anti-adhesive layer 109 may be the first coating applied to the image surface side 112 of the ribbon 100 and may include a binder, perhaps a wax or resin material. Then, an indicator material layer 108 may be coated over the anti-adhesive layer 109. In addition, a protective layer (not shown) may be coated over the indicator material layer 108 to prevent the indicator material or the indicator material layer 108 from spreading or peeling off the ribbon before it has been heated by the thermal printhead.

[0266] In one example, the support substrate 104 can be treated by corona effect, flame or plasma to provide a bond between the support substrate 104 and the bonding layer 106 or other corresponding layer encapsulating the material for exposure to the environment (for example, the indicator material layer 108) which is releaseable in the printing process, but keeps the indicator material for exposure to the environment on the support substrate through all the stages of a printing process up to the transfer onto the printable substrate.The composition or chemistry of the environmental exposure indicator material in the bonding layer 106, or other corresponding layer encapsulating the environmental exposure indicator material (for example, the indicator material layer 108), can be adapted to the support substrate 104 so that an additional anti-stick layer 109 is unnecessary (for example, for ribbons 100 used in hot stamping).

[0267] The indicator material layer 108 or the bonding layer 106 may comprise a diacetylene monomer powder dispersed in a nitrocellulose resin. In addition, the indicator material layer 108 or the bonding layer 106 may comprise diacetyl monomer powder and / or acrylic resins. Furthermore, the bonding layer 106 may also comprise carnauba wax, candelilla wax, hydrocarbon wax, or a combination thereof. Both carnauba wax and candelilla wax have adhesive properties that are imparted to the indicator material for environmental exposure or to a corresponding indicator material layer 108 (see [Fig. 2A]). Other waxes or additives with sufficient adhesive properties and suitable melting points may be used. In one example, the bonding layer 106 may comprise diacetyl monomer powder and a resin emulsion. The resin emulsion can be formed from the Joncryl® 538A emulsion and the Actega Carnauba wax emulsion produced by Aquacer 2650.

[0268] In another example, the ribbon 100 may include a non-stick layer 109 such as a thin layer (for example, from about 0.5 micrometers to 3 micrometers or from about 0.5 micrometers to 1.5 micrometers) of an adhesive material whose melting point is such that it loses its cohesive strength when subjected to heat from an active pen or printhead. The non-stick layer 109 may include a layer of wax or a heat-sensitive wax-like material that forms a strong bond with the environmental exposure indicator material or its associated encapsulation layer. The heat from the thermal printhead causes the heat-sensitive wax to separate, allowing the environmental exposure indicator material or its associated encapsulation layer (for example, the bonding layer 106) to separate from the support substrate 104 of the ribbon 100.Heat-sensitive wax or wax-like materials are particularly advantageous for thin films and tapes 100. For example, a heat-sensitive wax can provide strong adhesion at both interfaces between the support substrate 104 and the layer encapsulating the material for environmental exposure (e.g., the bonding layer 106) at room temperature (e.g., about 20°C to 25°C, preferably about 23°C or about 73.4°F). In addition, a heat-sensitive wax can advantageously provide bonding at room temperature and release at high temperature (e.g., a temperature above approximately 120°C or about 250°F, e.g., approximately 300°F), thus allowing greater flexibility and broader compatibility in the selection and / or formulation of indicator materials for environmental exposure.

[0269] As mentioned above, in some examples, the non-stick layer 109 can be avoided by using a film, support, or support substrate 104 having low-adhesion properties. Processes using support substrates 104 thicker (e.g., 12 to 24 microns), such as hot stamping in a "duplicate and move" mode or in a rotary mode, may work better using a low-adhesion support substrate 104 rather than a heat-sensitive wax as an anti-stick layer 109.

[0270] The bonding layer 106 or other corresponding layer encapsulating or containing the environmental exposure indicator material may include an ink, dye, paint, toner, or wax, which is applied to a thermal ribbon 100 in a first color state. The environmental exposure indicator material may include liquids, pastes, dyes, pigments, powders, polymers, etc. The bonding layer 106 or other corresponding layer encapsulating or containing the environmental exposure indicator material may be applied to the support substrate 104 or the anti-adhesive layer 109 with a bar coating machine, a gravure coating machine, or with a precision coating device, such as a slot coating machine, a micro-etching coating machine, a curtain coating machine, or the like.Initially, the layer encapsulating or containing the environmental exposure indicator material (e.g., the 106 bonding layer) may have little to no color at all; then, the color or characteristics of the layer may change after being exposed to an environmental condition (e.g., weather, temperature, etc.). The thickness of the layer encapsulating or containing the environmental exposure indicator material (e.g., the 106 bonding layer) may depend on the printing application and the type of environmental exposure indicator material used.

[0271] In one example, the bonding layer 106 or the indicator material layer 108 may have a thickness of approximately 2 to 50 micrometers. For example, the bonding layers for active indicators for cumulative diacetyl exposure may have a thickness of up to 25 micrometers. In addition, the bonding layers for SCC threshold temperature indicators may have a thickness of up to 50 micrometers or more.

[0272] In one example, the environmental exposure indicator material, such as a temperature exposure indicator material, in the bonding layer 106 may be a pigment dispersion in nitrocellulose, which is suitable for digital thermal transfer printing. In another example, the environmental exposure indicator material in the bonding layer 106 may be a pigment dispersion in an acrylic resin. The environmental exposure indicator material may be incorporated into a synthetic resin composition to form the bonding layer 106. Furthermore, the environmental exposure indicator material may include an indicator such as a pigment of Diacetylene monomer, a matched pair of a leuco dye precursor and a leuco dye developer, a composition of free or encapsulated thermochromic liquid crystals, a wax or wax-like light-scattering particle, or any other thermochromic material. For example, the indicator material for environmental exposure may be an indicator such as a diacetylene monomer pigment, a matched pair of a leuco dye precursor and a leuco dye developer, a composition of free or encapsulated thermochromic liquid crystals, a wax or wax-like light-scattering particle, or any other thermochromic material dispersed in an acrylic resin.The 106 bonding layer can include a high content of reactive or dynamic components (e.g., environmental exposure indicator material) to allow for thinner layers that encapsulate the environmental exposure indicator material, which can advantageously facilitate faster thermal transfer and printing. 106 bonding layers with high thermal transfer rates can also advantageously facilitate thermal transfer ribbons with thicker 106 bonding layers, allowing for the application of more environmental exposure indicator material onto the printable substrate.

[0273] The adhesive layer 110 may include a heat-activated adhesive. For example, the adhesive layer 110 may change from a first state (e.g., a hard, non-sticky material at room temperature) to a second state (e.g., a soft, shape-conforming, and sticky material) when heated. In one example, the adhesive may be incorporated into the bonding layer 106, thus forming a bonding layer 106 with thermal adhesive properties. In one example, the thermal adhesive may be a thermoplastic. Furthermore, the adhesive may be chosen according to the printable substrate, as some adhesives may not adhere well to certain substrates. For example, an adhesive may be specifically formulated or selected to adhere to specific printable substrates (e.g., polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), etc.).

[0274] In the example illustrated in [Fig. 2C], the bonding layer 106 can serve to encapsulate the environmental exposure indicator material and also act as a binder that helps to bond the environmental exposure indicator material to the support substrate as well as to the printable support once the ribbon is heated by a print head. In other examples, a separate adhesive layer 110 can be applied separately to a layer of indicator material 108 (see [Fig. 2A]) to form a thin, continuous layer on the image-side surface 112 of the ribbon 100. The environmental exposure indicator material or pigment the dispersed environment in an adhesive binder to form a bonding layer 106 can advantageously allow thinner thermal ribbons 100 with the same print quality as thicker thermal ribbons 100, and also eliminate the separate process of applying the adhesive 110 to the indicator material layer 108.

[0275] Adhesives by way of example may be solvent-based (e.g., Joncryl® 682), aqueous emulsion-based (e.g., Joncryl® 538a), and / or water-soluble, or a combination thereof. For example, the adhesive layer 110 may comprise a solution of Joncryl® 682 in a solvent, an emulsion of Joncryl® 538A, or a Michelman adhesive emulsion, or similar. Similarly, the bonding layer 106 may comprise the adhesives discussed above. In one example, the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A.

[0276] The adhesives may have a melting temperature which is in the range chosen in the group consisting of about 50 to 110°C, about 60 to 110°C, about 70 to 110°C, about 80 to 110°C, about 90 to 110°C, about 100 to 110°C, about 50 to 100°C, about 60 to 100°C, about 70 to 100°C, about 80 to 100°C, about 90 to 100°C, about 70 to 90°C, and about 80 to 90°C.

[0277] In one example, particularly for certain environmental exposure indicator materials, such as temperature exposure indicator materials (e.g., time-temperature indicators), the adhesive should be configured so that it has a negligible influence on the color or appearance of the environmental exposure indicator material when printed. For example, the adhesive (e.g., the adhesive layer 110) may be colorless or barely perceptible. Adhesives for use with visual indicator materials preferably have little to no influence on the development of the indicator. Similarly, the anti-adhesive layer 109 is preferably adapted to have little to no interference with the development of the indicator.For example, both the anti-stick layer 109 and / or the adhesive (e.g., the adhesive layer 110) are configured so that they neither advance nor delay the development of the indicator material for exposure to the environment. Direct Thermal Supports

[0278] Another thermal printing technology for printing data shapes or images, such as barcode symbols, is direct thermal printing. A direct thermal printer does not use a ribbon, but instead... The printable medium itself is the thermal media. Direct thermal media is made from or coated with a thermochromic material that changes color when exposed to sufficient heat, such as a leuco dye, which changes from a colorless chemical form to a black or colored chemical form. The strip of direct thermal media is pressed against and moved in front of the thermal print head. The thermal print head receives data from a rendered bitmap and heats specific heating elements in the addressable heating element array according to the data.

[0279] The heat from the heated elements causes the thermochromic material on the printable substrate to change from colorless to black or from colorless to colored. The printhead heating elements that are not heated do not cause a color transition. In some direct thermal substrates, a first area of ​​the printable substrate comprises a thermochromic material that changes from colorless to a first color, while a second area of ​​the printable substrate comprises a thermochromic material that changes from colorless to a different second color. Some direct thermal substrates include a multilayer arrangement comprising a first layer of a first color and a second, non-transparent layer of a second color. For multilayer arrangements, the heat from the heated elements of the printhead causes the second layer to become transparent, revealing the color of the first layer.

[0280] As illustrated in [Fig. 3A], a direct thermal printing substrate or direct thermal printer material 200 may comprise a thermal paper substrate 210 and an indicator material layer 220. The indicator material layer may comprise an environmental exposure indicator material. In some examples, the indicator material layer 220 may be applied according to a specific path, geometry, pattern, etc., to form an environmental exposure indicator, such as a temperature exposure indicator.

[0281] In one example, the thermal paper substrate 210 is configured to be printed by a direct thermal printing process with a heated thermal printhead. The thermal paper substrate may have a printing temperature and be capable of changing color when heated by the heated thermal printhead to or above the printing temperature. Furthermore, a temperature exposure indicator disposed on the thermal paper substrate may include an environmental exposure indicator material that is configured to change color state in response to temperature exposure above a predetermined threshold temperature, which is below the printing temperature. In one example, the exposure indicator material the environment, such as an indicator material for temperature exposure, is a dye encapsulated in a matrix.

[0282] The direct thermal printer material, and more specifically the 210 direct thermal paper substrate, is configured to image a data shape on the direct thermal paper material at a printing temperature above the temperature threshold temperature of the temperature exposure indicator material. The data shape can be imaged without the temperature exposure indicator material changing its color state.

[0283] As illustrated in [Fig. 3B], a label 250 may include a flexible substrate 260. The flexible substrate 260 may be a backing substrate 104, a ribbon 100, or a paper substrate, such as a direct thermal paper substrate. The flexible substrate 260 has a first face 262 and a second face 264. The first face 262 may be an adhesive 270. In another example, the adhesive 270 may be an adhesive layer applied to the flexible substrate 260. The second face 264 may be configured to be imaged or printed. In one example, the second side can consist of one or more layers of ink 272. In one example, the second side has a visible, printed mark 280 and an overlapping printed mark 290. The overlapping mark 290 can be configured to change opacity below a transition temperature in order to obscure the visible mark.In another example, the overlapping mark 290 can be configured to change opacity above a first transition temperature in order to obscure the visible mark. The change in opacity can be due to a change in the color state, as described in the various other examples here.

[0284] In one example, the overlapping mark 290 may initially be transparent or may transition from opaque to transparent. For example, the overlapping mark may change from opaque to transparent at a second transition temperature, which may be the same as the first transition temperature or may be higher than the first transition temperature. The adhesive 270 or the adhesive layer may be configured to attach the label 250 to a bottle or other product. In one example, the second transition temperature may be configured to change opacity when a liquid inside the bottle reaches a threshold temperature, such as 18°C. In one example, the visible mark may be light blue and the overlapping mark, when opaque, may be dark blue.

[0285] The flexible substrate 260 may include a thermochromic layer. The thermochromic layer may be the ink layer 272 or one of the layers within the ink layer(s) 272. The thermochromic layer may be configured to be printed by a thermal printer at an imaging temperature. The layer thermochromic can be a top layer or top coating configured to be printed by the thermal printer.

[0286] Materials for Environmental Exposure as Examples

[0287] As discussed above, the environmental exposure indicator material may include an ink, dye, paint, toner, or wax that is applied to a thermal transfer ribbon 100 or a direct thermal printing substrate 200. The environmental exposure indicator material may include liquids, pastes, dyes, pigments, powders, polymers, etc.Examples of indicator materials for environmental exposure, or indicators printed from them, include temperature monitors, measuring either cumulative heat exposure or exceeding one or more fixed high or low temperature threshold values; time monitors, time-temperature product monitors, monitors of exposure to nuclear radiation; gas or moisture exposure monitors, each exceeding a cumulative exposure threshold or an instantaneous threshold value; and light exposure, such as ultraviolet ("UV") exposure.

[0288] In one embodiment, the environmental exposure indicator material may be sensitive to an environmental factor such as temperature, time, time and temperature, freezing, radiation, toxic chemicals, or a combination of such factors, or similar factors. For example, the environmental exposure indicator material may be a temperature exposure indicator material, such as (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature;(d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second lower temperature threshold; or (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

[0289] In another example, the indicator material for environmental exposure may be (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; or (h) an indicator material configured to change color state in response to exposure to moisture. Indicator materials, by way of example, particularly luminescent (or more specifically, phosphorescent or fluorescent) indicator materials, are described in U.S. Patent Application No. 17 / 007,795. For example, the indicator material may be, or may include, a radiation indicator that exhibits a visual color change from yellow to red when exposed to radiation, such as GEX Corporation's P8200. In one example, the radiation indicator may be applied to a support substrate 104 with an acrylic-based emulsion that acts as an adhesive to the indicator material disposed of in a polyvinyl butyral ("PVB") resin coating. Indicators for moisture exposure may be configured to change color in the presence of liquid moisture and high humidity.For example, Kimberly-Clark produces color-changing inks that change from yellow to blue when exposed to a liquid or water vapor. The color change is instantaneous with exposure to a liquid, such as water, but the color change may take longer, depending on the exposure time and humidity, when exposed to water vapor.

[0290] For indicators for upward temperature exposure, threshold temperatures by way of example are within the selected range of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C. In some embodiments by way of example, the threshold temperature is one of 35°C, 40°C, 45°C, 50°C, and 60°C. In a specific embodiment, the threshold temperature is 40°C. Furthermore, a threshold temperature range by way of example may be from 0°C to -80°C. C. Thermal Printing Process (with Ribbon)

[0291] The print head can be raised and lowered so that it is in contact with the 100 ribbon only for the time (and distance) necessary to provide satisfactory printing. By selectively raising and lowering the print head at predetermined intervals, less 100 ribbon can be used during printing operations, thus enabling a greater number of print operations per 100 ribbon.

[0292] Figure 4 illustrates a printing process by way of example at different printing stages or actions 300A to 300D. First and second printing actions leading to a first printed indicator 310a and a second printed indicator 310b are illustrated in stages 300A and 300B. For example, a first printing action includes the application of heat to the thermal transfer ribbon 100 via the print head 305. When the print head 305 is pressed against the transfer ribbon 100 and into the printable substrate 315, an indicator for Environmental exposure, such as a temperature exposure indicator 310a, is printed onto the printable substrate 315. The ribbon 100 is advanced along the direction of travel (for example, the print head 305 may be stationary), and the print head 305 can press the ribbon 100 into the printable substrate 315 again to form a second environmental exposure indicator, such as a temperature exposure indicator 310b. After a printing operation, the ribbon 100 may include a cavity where one or more layers (for example, the bonding layer 106) have been thermally bonded to the printable substrate 315. For example, indicators 310a and 310b correspond to cavities 312a and 312c, respectively.Print actions can be selectively spaced along the ribbon 100 to allow portions of the ribbon 100 adjacent to a print action to cool properly before that portion of the ribbon is used for printing.

[0293] For example, as illustrated in [Fig. 4], the print head 305 can use a "print, gap, gap" approach that skips two print regions on the ribbon per print in order to leave sufficient ribbon gap between each print action. As illustrated in step 300C, after reaching the end of the ribbon 100, the ribbon 100 can be moved in the opposite direction to perform two additional print operations or actions, thus printing the indicators 310c and 310d and leaving the respective cavities 312c and 312d on the ribbon 100. A controller can coordinate the print locations so that the indicator 310c is printed in one of the gap regions of the first pass (for example, the last gap of the first pass is where printing begins for the second pass in the opposite direction).

[0294] Again, as illustrated in step 300D, after reaching the end of the ribbon 100, the ribbon 100 can move in the opposite direction (e.g., to the left) to perform two additional printing operations or actions, thus printing the indicators 310e and 310f and leaving the respective cavities 312e and 312f on the ribbon 100. A controller can coordinate the printing locations so that the indicator 310e is printed in the last remaining gap region (e.g., between the cavities 312a and 312d) from both the first and second passes. It should be understood that other printing patterns and / or commands can be used. For example, the printer can use a "print, gap, print, gap" pattern.In other examples, the ribbon can be moved transversely (e.g., in and out of the page) for subsequent printing operations in order to utilize additional dynamic or active ink from the ribbon.

[0295] The print head 305 of [Fig. 4] can be a print head near the edge. For example, indicators can be printed from the transfer ribbon Thermal transfer is achieved using a thermal transfer printer with printheads positioned near the edge for high-speed applications. For high-speed applications, the 100 transfer ribbon may contain higher percentages of reactive components in the ink layer, resulting in a thinner ink layer that allows for faster heat transfer through the ribbon. In other examples, the ribbon may include an adhesive ink layer in a pattern matching the intended design on the product. This pattern is formed by die-cutting a solid coating of indicator ink onto a separate backing, followed by a transfer onto the 104 non-stick coated backing. This structure separates the formation of the desired ink pattern from the transfer process, facilitating high-speed transfer.This also improves the quality of the leading and trailing edges of the transfer-printed ink, which are typically degraded at high speeds. In other examples, multiple 305 printheads can operate on a single 100 ribbon. For example, 310a-f indicators can be printed by one or more 305 printheads.

[0296] Referring again to Figures 1, 2A, 2B and 2C, the bonding layer 106 or the indicator material layer 108 may include patterns or may be selectively coated onto the ribbon 100. For example, the ribbons 100 may be selectively coated with several strips of different materials (e.g., indicator materials for environmental exposure) and different printheads 305 may be configured to print specific materials placed on the ribbon 100. The bonding layer 106 or the indicator material layer 108 may include patterns or may be selectively coated onto the ribbon 100. For example, the bonding layer 106 or the indicator material layer 108 may be selectively coated onto the ribbon 100 to reduce waste of the indicator material for environmental exposure.

[0297] During a thermal printing process, heat from a thermal printhead passes through the support substrate 104 and either the bonding layer 106 or the indicator material layer 108, depending on the ribbon configuration. Under the same process conditions (e.g., same printhead, same temperature, same coating and support properties), less heat passes through a thick bonding layer 106 or a thick indicator material layer 108 than through a thin bonding layer 106 or a thin indicator material layer 108. Thus, the adhesive in either the adhesive layer 110 or the bonding layer 106 can be selected according to the process parameters. For thicker indicator material layers 108, adhesives with activation temperatures Lower values ​​should be chosen to ensure proper adhesion of the bonding layer 106 or the indicator material layer 108 to the printable substrate.

[0298] During the printing process, the print head 305 can be heated to a printing temperature, which can also be called the printing temperature or heated heat transfer temperature. In one example, the heated heat transfer temperature is within the range chosen from the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C. For example, the 305 printhead can be configured to heat a portion of the 100 thermal transfer ribbon or direct thermal printing media to one of the heat transfer temperatures discussed above.

[0299] Labels (e.g. Direct Thermal Label)

[0300] Figure 5 illustrates a label 400 configured to indicate exposure to temperature above a threshold temperature. In one example, the label 400 comprises a substrate 410 with a first face 412 and a second face 414. The first face 412 may include a printable area and an indicator material for environmental exposure. In one example, the indicator material for environmental exposure may be a temperature indicator material, such as (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature;(c) a reversible thermochromic indicator material configured to change its color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; or (e) an irreversible thermochromic indicator material configured to change its color state in response to cumulative heat exposure over time. In another example, the indicator material for environmental exposure could be (f) an indicator material configured to change its color state in response to radiation exposure; (g) an indicator material configured to change its color state in response to light of a predetermined wavelength;or (h) an indicator material configured to change color state in response to exposure to moisture. In the illustrated example, an adhesive layer 430 is positioned adjacent to the second face 414. In addition, a layer; coating 420 is positioned adjacent to the first face 412 and the indicator material is between the coating layer 420 and the substrate 410.

[0301] The printable area may include one or more of the environmental exposure indicator materials discussed above, such as a direct thermochromic material or the irreversible thermochromic indicator material. In one example, the coating layer may be a resin from a thermal transfer ribbon or a thermally printed overlayer. In another example, the coating layer may be a varnish.

[0302] Figures 6A, 6B, and 5C illustrate an exemplary embodiment of a direct thermal label 500. In one example, the direct thermal label 500 can be created from a thermal paper material or a thermal paper substrate 210 onto which an environmental exposure indicator has been applied. For example, the environmental exposure indicator can be a reversible thermochromic temperature indicator, which can be applied in a layer of indicator material 220 onto the thermal paper substrate 210. At room temperature, the thermochromic temperature indicator can appear black or another solid dark color (see [Fig. 6A]) and can change to another color state (e.g., colorless) at temperatures above 40°C.The label 500 can be created by imaging the thermal paper substrate 210 with the thermochromic temperature indicator 510 applied to it with a barcode symbol 520. The barcode symbol 520 can be imaged without activating the color change in the temperature indicator 510, even if the printing temperature used to image the barcode symbol 520 is higher than the activation temperature (e.g., 40°C) of the temperature indicator 510.

[0303] If the label 500 is exposed to a temperature above the activation temperature of 40°C, as illustrated in [Fig. B], the reversible thermochromic temperature indicator 510 changes from a solid dark color to a colorless state, thus revealing the previously imaged barcode symbol 520. Then, when the label 500 is exposed to temperatures below the activation temperature of 40°C, as illustrated in [Fig. C], the reversible thermochromic temperature indicator 510 changes back from a colorless state to a solid dark color, thus masking or concealing the previously imaged barcode symbol 520. Processes and Products by Process

[0304] Figure 7A illustrates a flowchart of an example process 700 for manufacturing a thermal transfer ribbon, according to an example embodiment of this disclosure. Although the example process 700 is described with reference to the flowchart shown in Figure 7A, it will be understood that Numerous other methods for performing the actions associated with process 700 can be used. For example, the order of some of the blocks can be changed, some blocks can be combined with other blocks, blocks can be repeated, and some of the blocks described are optional.

[0305] The method by way of example 700 may include providing a support substrate (block 702). The support substrate may be a blank thermal transfer ribbon. In addition, the method 700 may include providing a temperature indicator material (block 704). The temperature indicator material may be configured to change color state in response to exposure to a temperature above a threshold temperature. The method 700 may also include coupling the temperature indicator material to the support substrate by means of a bonding layer (block 706). For example, the temperature indicator material may be coupled to the support substrate by means of a bonding layer. The bonding layer may be configured to release the temperature indicator material onto a printable substrate when heated by a print head.In one example, the bonding layer has a melting temperature higher than the threshold temperature.

[0306] Figure 7B illustrates a flowchart of an example method 710 for applying a temperature indicator to a printing surface with a thermal transfer ribbon, according to an example embodiment of this disclosure. Although the example method 710 is described with reference to the flowchart shown in Figure 7B, it will be understood that many other methods of performing the acts associated with method 710 can be used. For example, the order of some of the blocks can be changed, some blocks can be combined with other blocks, blocks can be repeated, and some of the blocks described are optional.

[0307] The method by way of example 710 may include receiving a trace of a temperature indicator (block 712). For example, a printer may be loaded with a thermal transfer ribbon having a support substrate and a temperature exposure indicator material coupled to the substrate via a bonding layer. The printer may receive a trace of the temperature indicator. In one example, the temperature indicator is formed by the temperature exposure indicator material of the bonding layer. In another example, the temperature exposure indicator material is configured to change color state in response to exposure to a temperature above or below a predetermined threshold temperature.

[0308] The method 710 may also include heating the bonding layer of a thermal transfer ribbon with a print head to a respective temperature at or above a melting temperature of the bonding layer, causing the bonding layer to transfer from the thermal transfer ribbon to a printing surface to print the temperature indicator according to the received pattern (block 714). In one example, the melting temperature of the bonding layer is above the threshold temperature.

[0309] Figure 7C illustrates a flowchart of an example process 720 for manufacturing a temperature-indicating printing material according to an example embodiment of this disclosure. Although the example process 720 is described with reference to the flowchart shown in Figure 7C, it will be understood that many other methods of performing the acts associated with process 720 may be used. For example, the order of some of the blocks may be changed, some blocks may be combined with other blocks, blocks may be repeated, and some of the blocks described are optional.

[0310] The method 720, by way of example, may include receiving a thermal paper material (block 722). In addition, the method 720 may also include applying a thermochromic temperature indicator material to the thermal paper material (block 724). For example, the thermochromic temperature indicator material may be applied as a top layer to the thermal paper material. The thermochromic temperature indicator material may be configured to change color state in response to reaching a temperature lower than the printing temperature of the thermal paper material.

[0311] Figure 7D illustrates a flowchart of an example process 730 for manufacturing a temperature exposure indicator according to an example embodiment of this disclosure. Although the example process 730 is described with reference to the flowchart shown in Figure 7A, it will be understood that many other methods of performing the steps associated with process 730 may be used. For example, the order of some of the blocks may be changed, some blocks may be combined with other blocks, blocks may be repeated, and some of the blocks described are optional.

[0312] The method 730, by way of example, may include receiving thermal paper material to which a thermochromic temperature indicator (block 732) has been applied. In one example, the thermochromic temperature indicator is configured to change color state above a threshold temperature. The method 730 also includes printing on the thermal paper material using a direct thermal printing process through the thermochromic temperature indicator with a thermal printhead that brings portions of the thermal paper material to a printing temperature above the threshold temperature without triggering a change of the color state of the thermochromic temperature indicator (block 734).

[0313] Figure 7E illustrates a flowchart of an example process 740 for manufacturing thermal paper for environmental exposure, according to an example embodiment of this disclosure. Although the example process 740 is described with reference to the flowchart shown in Figure 7E, it will be understood that many other methods of performing the steps associated with process 740 may be used. For example, the order of some of the blocks may be changed, some blocks may be combined with other blocks, blocks may be repeated, and some of the blocks described are optional.

[0314] The process 740, by way of example, may include adding one or more reversible thermochromic pigments to an acrylic binder and a water-based solvent to create a reversible thermochromic formulation (block 742). In one example, the acrylic binder may be a clear, viscous acrylic resin solution, such as Ottopol 25-30 supplied by Gellner Industrial. Furthermore, the water-based solvent may be water. The process 640 may also include coating the thermal paper with the reversible thermochromic formulation (block 744). In one example, the thermochromic formulation may be between 20% and 30% (for example, weight percentage) of thermochromic pigment(s). In addition, the formulation may be between 40% and 50% (for example, weight percentage) of acrylic binder.In one example, the thermochromic formulation might contain between 24% and 26% (e.g., weight percentage) of thermochromic pigment(s) and between 44% and 49% (e.g., weight percentage) of acrylic binder. The thermochromic formulation might have a viscosity (cps) between 150 cps and 300 cps and a flow stress between 3.0 dynes / cm² and 17 dynes / cm².

[0315] Figure 7F illustrates a flowchart of an example process 750 for manufacturing a form of data for environmental exposure, according to an example embodiment of this disclosure. Although the example process 750 is described with reference to the flowchart shown in Figure 7F, it will be understood that many other methods of performing the acts associated with process 750 may be used. For example, the order of some of the blocks may be changed, some blocks may be combined with other blocks, blocks may be repeated, and some of the blocks described are optional.

[0316] The method by way of example 750 may include imaging thermal paper with a data form through at least one layer of a reversible thermochromic ink to create a data form for environmental exposure (block 752). The reversible thermochromic ink may be configured to change color state from a first state or color (for example, blue) to a second state (for example, colorless) or color in response to exposure to a temperature above a threshold temperature. In one example, the threshold temperature is 18°C. The reversible thermochromic ink layer can be applied to the thermal paper as described in process 740 above.

[0317] Figure 7G illustrates a flowchart of an example process 760 for manufacturing an environmental thermal transfer ribbon according to an example embodiment of this disclosure. Although the example process 760 is described with reference to the flowchart shown in Figure 7G, it will be understood that many other methods of performing the acts associated with process 760 may be used. For example, the order of some of the blocks may be changed, some blocks may be combined with other blocks, blocks may be repeated, and some of the blocks described are optional.

[0318] The process 760, by way of example, may include adding one or more thermochromic pigments to a binder and a solvent to create a thermochromic formulation (block 762). The binder may be an acrylic binder. Furthermore, the solvent may be an aqueous solvent. In another example, the binder may be nitrocellulose and the solvent may be EEP / IPA. In addition, the process 760 includes coating a thermal transfer ribbon or thermal paper with the thermochromic formulation (block 764). For example, the thermochromic formulation may be applied to any of the thermal transfer ribbons or thermal papers described herein.

[0319] It will be understood that the formulations (e.g., environmental indicator formulations or thermochromic formulations), the environmental indicators (e.g., temperature indicators), and the printing substrates or media (e.g., thermal transfer ribbons and direct thermal paper) may have one or more of the properties described herein. Furthermore, the above processes may be adapted to create each of the inks, formulations, etc., from the experimental results discussed below. Experimental Results

[0320] Thermochromic pigments have been used to prepare matrices of specific formulations, enabling their use in various printing processes. Water-based formulations were suitable for flexographic printing and coatings applied to paper for direct thermal printing. In some cases, certain solvents were shown to be incompatible with direct thermal papers, as the solvents interacted with the paper components. Solvent-based formulations were suitable for coatings applied to ribbons for thermal transfer printing.

[0321] Thermochromic pigments must have a small particle size for use in flexographic printing applications (ideally between 3 and 6 µm). The pigments can be added to both aqueous and solvent-based systems. However, the solvents must be chosen appropriately to avoid damaging the microcapsule structure and thus affecting the reversible color-change characteristics.

[0322] Work was carried out to evaluate the stability of pigments in various solvents, including acetone, methyl ethyl ketone ("MEK"), toluene, butyl alcohol, and IPA (report MS 19002). Specifically, thermochromic pigments were obtained from Atlanta Chemical Engineering, New Color Chemical, and Glitter Unique and were dispersed in different solvents. The results indicated that toluene and butyl alcohol are more compatible with reversible thermochromic pigments than acetone and MEK.

[0323] Compatibility of Thermochromic Pigments with Solvents - Experiment

[0324] Pigments from Atlanta Chemical Engineering, New Color Chemical, and Glitter Unique were added to a glass flask to prepare a 2% pigment formulation in 5 g of solvent. After at least 30 minutes on an orbital shaker at room temperature, the pigments appeared to be well dissolved in each solvent (acetone, MEK, toluene, and butyl alcohol).

[0325] The pigment from Atlanta Chemical Engineering changes from blue to pink above an activation temperature of 12°C and has a particle size specified by the manufacturer as being between 2 µm and 15 µm. To demonstrate the proper color change, the samples were placed in a freezer for 15 minutes. The pigment samples in acetone appeared cloudy at room temperature and did not show a color change to blue when cooled in the freezer. Furthermore, the pigments dissolved in MEK showed a cloudy blue color upon cooling. The above results indicate that the thermochromic pigment was altered when dissolved in acetone and MEK.

[0326] The pigment in Glitter Unique changes from violet to green above an activation temperature of 22°C, but the particle size has not been established by the manufacturer. Samples of the pigment in acetone appeared cloudy at room temperature and did not show a color change to violet, indicating that the thermochromic pigment was altered when dissolved in acetone.

[0327] The pigment from New Color Chemical changes from black to pink above an activation temperature of 15°C and has a particle size established by the manufacturer between 2 µm and 6 µm. Samples of the pigment in acetone and MEK appeared cloudy at room temperature. The pigment in acetone did not show any color change to dark purple or black when cooled in the freezer. The pigment samples in MEK changed color upon cooling, but appeared Havana brown, not dark purple or black. The above results indicated that the thermochromic pigment was altered when dissolved in acetone and MEK.

[0328] The pigments from each manufacturer retained the color-changing characteristics as specified in toluene and butyl alcohol. In addition, the thermochromic pigments added to water showed good stability.

[0329] To obtain an acceptable flexographic coating and suitable direct thermal printing characteristics, the appropriate water-based binder must be selected. Examples and details of some water-based flexographic inks are described in Table 3 and the paragraphs following Table 3 below. Water-based binders with a neutral pH (7) are recommended, avoiding acidic or alkaline binders as they may damage the microcapsule structure. For example, Neocryl BT-24 (pH 5.3) has been shown to be unsuitable, as the flexographic coating was striated and uneven. However, Neocryl A-1052 (pH 8.5) provides a much more even coating. In addition, the appropriate pigment-to-binder ("P / B") ratio and viscosity must be identified for a smooth, even coating. Inks with a high P / B ratio appear lumpy and uneven.For example, Ottopol 25-30 was used in conjunction with a black to colorless pigment at 35°C to prepare formulations with a W / B ratio of 3.0, 1.5, and 1.0, applied as a coating on direct thermal paper (2000D) using a flexo hand tester. Inks with a W / B ratio of 3.0 resulted in a rough, uneven, and non-uniform coating. Reducing the W / B ratio to 2.0 improved the coating, and the optimal W / B ratio was found to be between 2.0 and 1.5. The binder that gave the best results was Ottopol 25-30, but Epotuf 91-263 also gave acceptable results.

[0330] For solvent-based coatings manufactured for thermal transfer ribbons, a suitable binder with the desired adhesive properties must be selected, and the ink must be applied to the ribbon at an appropriate thickness (and at an ideal pigment concentration as a ratio or percentage of the total solids content) to ensure complete and uniform transfer to the substrate during the thermal printing process. Formulations manufactured using a water-based binder system do not provide homogeneous coverage and do not exhibit good transfer characteristics. Black to colorless at 35°C was applied as a coating with the water-based binder system, resulting in poor performance. Ribbons coated with Formulations using Joncryl 538A emulsion (45% solids) did not properly transfer the printed images.

[0331] High-performance adhesives will dry without being tacky while retaining good flexibility to minimize peeling from the substrate. The adhesive needs to melt, detach from the tape, and adhere to the substrate during the printing process. The melting temperature needs to be within a range achievable by the print head; the area of ​​the fused image requires greater adhesion to the substrate than the tape's non-stick coating.

[0332] As illustrated below in Table 2, various thermochromic pigments exhibiting reversible color change were added to an acrylic / solvent resin matrix containing a small amount of TiO2 for opacity. The formulations were applied as a coating to a blank thermal ribbon, and the ribbons were then used to thermally transfer the thermochromic ink onto samples of 2059 paper label material. The samples were laminated, die-cut, and tested for their color change response. Ribbons coated with an optimized formulation having approximately 58% solids, using a No. 12 Mayer rod, demonstrated that the thermochromic inks can be printed by thermal transfer.The results confirmed that the thermochromic prototypes exhibit a reversible color change that is unambiguously within ±2°C of the activation temperature established by the manufacturer.

[0333] [Tab 1] Table 1 - Thermochromic Pigment Formulations Direct Thermal Flexo Ink Coating Thermal Transfer Thermochromic Pigments Micro-encapsulated uco dye pigments Micro-encapsulated uco dye pigments Micro-encapsulated uco dye pigments Pigment particle size <10µm <10µm <10µm Binders Neocryl A-1052; Neocryl BT-24; Epotuf 91-263; Ottopol 25-50 E; Ottopol 25-30 Neocryl A-1052; Neocryl BT-24; Epotuf 91-263; Ottopol 25-50E; Ottopol 25-30 Joncryl 682; Joncryl 538A (45% solids); Neocryl B-818 Solvents Water; n-Propanol IPA Water; Butyl Alcohol Other additives Kaolin; TiO2; Kaolin; TiO2; TiO2; Sipernat 22LS; Tego Twin 4100; Teg o Foamex 1488; Tego Gide 406 Tego Twin 4100; Tego Foamex 1488; T ego Gide 406 silica

[0334] [Tab 2] Table 2 - Thermochromic Ink Formulations Used for Coating on a Thermal Transfer Ribbon Pigment and Supplier Formulation Details Tape Coating Thickness / Coat Weight Result Sample ID Pigment TC Joncryl 682 Solvent TiO2 Pigment Black to Yellow at 25°C (Atlanta Chemical Engineering "ACE") 1253-1 Cl 37% 33% 27.5% Butyl Alcohol 2.5% Meyer Rod #30 No Transfer 1253-1 Cl (Diluted) 18.5% 34% 46% Butyl Alcohol 1.25% Meyer Rod #12 Good Transfer 1253-3 B 20% 35% 42% Butyl Alcohol 3.0% Meyer Rod #12 Good Transfer Black to Colorless at 35°C (ACE) 560-19 Test 30% 33% 35% IPA 2.0% 5.1 g / m² 8.6 g / m² 10.2 g / m² Good transfer Red to Green at 18°C ​​(ACE) 560-19 Test 30% 33% 35% IPA 2.0% 5.1 g / m² 8.6 g / m² 9.3 g / m² Good transfer Red to Green at 22°C Glitter Unique 1253-2 35% 32% 27% Butyl alcohol 5.7% Meyer stem #12 N / A 1253-2 B2 17.7% 33.5% 46% Butyl alcohol 2.8% Meyer stem #12 Good transfer 1253-3A 20% 35% 42% 3.0% Meyer Stem No. 12 Good transfer Butyl alcohol

[0335] EXAMPLE I - Reversible Thermochromic - Thermal Transfer Ribbon

[0336] Reversible thermochromic indicator materials configured to change color state in response to a temperature above a threshold temperature were tested. In one example, the indicator materials were reversible thermochromic color-changing pigments, obtained from Atlanta Chemical Engineering and Glitter Unique, which had different activation temperatures (e.g., threshold temperatures) and color-changing properties, such as (1) EXAMPLE IA - a pigment that changes from red to green above a temperature of 18°C ​​obtained from Glitter Unique, (2) EXAMPLE IB - a pigment that changes from black to colorless above a temperature of 35°C obtained from Atlanta Chemical Engineering ("ACE"), and (3) EXAMPLE IC - a pigment that changes from blue to colorless above a temperature of 12°C obtained from LCR Hallcrest (i.e., WB Flexo Ink).

[0337] The pigments described above were added (approximately 18% to 25% by weight) to formulate an indicator material, such as an ink, containing an acrylic binder (i.e., Joncryl 682 resin obtained from BASF) and an isopropyl alcohol ("IPA") solvent obtained from Sigma Aldrich, which was suitable for thermal transfer printing. The resulting indicator material was uniformly applied as a thin-layer coating with a layer weight of approximately 5 g / m² to 10 g / m² onto a thermal transfer ribbon 100 having a backing 102 and a non-stick layer 109 using a pilot reverse-etching coating machine. The ribbon was an IIMAK thermal transfer ribbon, in 4.5 micron film, with a backing layer of IIMAK WBE08700C at 0.06 g / m2 and an anti-stick coating of IIMAK WIS37UC at 0.54 g / m2.The coated ribbon 100 was then used on the Zebra ZT610 to thermally transfer print samples of different patterns onto the Z-Perform 2000T paper substrate. In addition, thermally transferred printed squares were made on Zebra 2000T labels, covering an existing printed message, to show the text "hide and reveal", as illustrated in [Fig.8A].

[0338] As illustrated in [Fig. 8A], the red-to-green samples (EXAMPLE IA) were observed to develop a red color under refrigerated conditions in an incubator at 5°C, and to develop a green color at room temperature. The black-to-colorless samples (EXAMPLE IB) were observed to develop a dark color at room temperature and to lose the dark color under high-temperature conditions in an incubator above 38°C.

[0339] As illustrated in [Fig. 8B], the black to colorless samples (EXAMPLE IB) and the blue to colorless samples (EXAMPLE IC) were used with 2D barcodes printed by direct thermal printing on Z-Perform 2000D paper coated with reversible ink. The blue to colorless samples were observed for the appearance of the blue color under refrigerated conditions, in an incubator at 5°C, and the disappearance of the blue color at room temperature.

[0340] EXAMPLE II - Semi-Reversible Thermochromic - Direct Thermal

[0341] Semi-reversible thermochromic indicator materials configured to change color state in response to a temperature above a threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold, were tested. In one example, a commercially available thick memory suspension, containing approximately 45% by weight of solids, was obtained from United Mineral & Chemical Corporation ("UMC"), called TM-MSL Black (50C-0C) Thick Memory Suspension Ink, exhibiting a semi-reversible color change from black to colorless between 0°C and 55°C. The thick memory suspension, in the form of an ink, was applied as a coating in a thin layer of approximately 12 µm onto Z-Perform 2000D direct thermal paper, and then the coated paper was used to thermally print 2D barcodes.

[0342] As illustrated in [Fig. 8C], at room temperature, 2D barcodes are visible on Z-Perform 2000D direct thermal paper. After heating above 55°C, the semi-reversible thermochromic indicator material becomes colorless, and the entire direct thermal paper portion is visible. Then, upon freezing below 0°C, the entire direct thermal paper portion appears black.

[0343] EXAMPLE III - Irreversible Thermochromic - Direct Thermal

[0344] Irreversible thermochromic indicator materials configured to change color state in response to a temperature above the threshold temperature were also tested. In one example, commercially available aqueous-based inks were obtained that change from colorless or opaque white to color (e.g., dark color) and have threshold temperatures of 65°C and 85°C. The 65°C ink was obtained from LCR Hallcrest (Kromagen Magenta), and the 85°C ink was also obtained from LCR Hallcrest (Kromagen Black). Each ink was applied as a coating (1.5 mil wet-applied film thickness) with a Bird film applicator bar onto a strip of Z-Perform 2000D direct thermal paper. The ink was allowed to dry at room temperature overnight.The sample strip of paper coated with irreversible ink was then placed on a Zebra ZT610 printer in "direct thermal" mode and 2D barcode images were successfully printed through the irreversible ink coating.

[0345] As illustrated in [Fig. 8D], a sample (EXAMPLE IIIA) that changes from colorless (e.g., opaque white) to black was applied to Z-Perform 2000D direct thermal paper. Below the specified activation or threshold temperature of 85°C, the imaged 2D barcodes are clearly visible on the direct thermal paper. Above the specified activation or threshold temperature, the imaged 2D barcodes appear obscured by the irreversible thermochromic ink.

[0346] Another example (EXAMPLE IIIB), illustrated in [Fig. 8D], shows Z-Perform 2000D direct thermal paper with colorless to magenta irreversible thermochromic ink applied as a coating on the paper (the ink is configured to change from colorless to magenta above a specified activation or threshold temperature of 65°C). Below the specified activation temperature, the irreversible thermochromic ink is colorless, and the imaged 2D barcodes are visible. As illustrated in the figure, portions of the imaged 2D barcode under a portion of the direct thermal paper coated with the irreversible thermochromic ink may appear magenta due to the ink being activated by the heat of the printing process.Once the sample (EXAMPLE IIIB) is exposed to a temperature above the activation or threshold temperature, the entire portion of the direct thermal paper coated with the irreversible thermochromic ink appears magenta.

[0347] EXAMPLE IV - SCC Polymer Emulsion Ink - Direct Thermal

[0348] As illustrated in [Fig. 8E] (Example IVA), a polymer emulsion SCC ink (with a threshold of 40°C) was applied as a coating using a Bird film applicator bar in a thin layer (1.5 mil wet-applied film thickness) over a black submersible print on Z-Perform 2000D thermal paper. Specifically, a square pattern printed by direct thermal printing was imaged onto the Z-Perform 2000D paper using a Zebra ZT610 printer. The coated paper was then used to print 2D barcodes by direct thermal printing onto the SCC emulsion layer. Table 5, illustrated in [Fig. 8E], shows the appearance of the samples before heating (opaque white) and after heating > 50°C, where the SCC emulsion ink becomes colorless and reveals the black printed substrate.

[0349] EXAMPLE V - SCC Emulsion Polymer Ink - Thermal Transfer Ribbon

[0350] In another example, an SCC thermal transfer formulation has been prepared to allow the coating to transfer evenly onto the substrate without flaking (e.g., adequate adhesion characteristics). Good-performance adhesives will dry without being tacky while retaining sufficient flexibility to minimize flaking. The adhesive needs to melt, detach from the ribbon, and adhere to the substrate in the printing process. The melting temperature needs to be within a range achievable by the printing heat. The melted image area needs greater adhesion to the substrate than the ribbon's anti-adhesive coating. Furthermore, because the SCC polymer emulsion ink is irreversible, it is crucial that thermal transfer printing be performed in such a way that the ink is not altered by heat during the printing process. During experimentation, aqueous emulsion adhesive mixtures (Joncryl 538A) did not adequately coat the ribbon or did not produce a usable ribbon after drying. Joncryl / MEK / SCC emulsion formulations were successfully applied as a coating to the thermal transfer ribbon, and 4 mm squares were printed onto a black 2059 paper label material or substrate.

[0351] Evaluation of Reversible Thermochromic Pigments at 18°C

[0352] Samples were obtained from ACE and Glitter Unique which change from colorless to blue at an activation temperature of 18°C. The pigment powders were used to manufacture both solvent-based screen printing ink and water-based flexographic ink. The formulations are described below in Table 3 and Table 4.

[0353] [Tab 3] Table 3 - Reversible Water-Based Flexographic Inks Blue - Colorless at 18°C Sample ID (supplier) % Pigment Binder and Solvent % Solids Viscosity (cps) Flow Stress (dynes / cm2) 1253-36 A (ACE) 26% Ottopol 25-30 to 44% (30% solids) in water 45% - - 1253-37 Al (ACE) 26% Ottopol 25-30 to 47% (30% solids) in water 42% 300 5.4 1253-37 A2 (Glitter Unique) 24.5% Ottopol 25-30 to 49% (30% solids) in water 41% 261 3.2 TI21135 (LCR Hallcrest) 24% - 39% 156 17

[0354] [Tab 4] Table 4 - Solvent-Based Reversible Screen Printing Inks Blue - Colorless at 18°C Sample ID (supplier) % Pigment Binder and Solvent % Solids Viscosity (cps) Flow Stress (dynes / cm2) 1253-36 B (ACE) 19% 30% Nitrocellulose in EEP / IPA - 4100 143 1253-36 B1 (ACE) 18% 30% Nitrocellulose in EEP / IPA - 2752 5.8 1253-36 B2 (ACE) 17% 30% Nitrocellulose in EEP / IPA 37% 2167 4.9 1253-37 B (ACE) 20% 30% Nitrocellulose in EEP / IPA 46% 3896 78 1253-37 B2 (Glitter Unique) 21% 30% Nitrocellulose in EEP / IPA 46% 4619 87

[0355] For solvent-based screen printing inks, stretches were made with Bird bars (1.5 mil, wet layer) for application onto 2059 paper label material. For water-based flexographic inks, stretches were made with a Harper QD hand flexo tester with an anilox roller (160 lpi / 12.0 BCM) for coating application onto Z-Perform 2000D paper. Sections of the stretches were used for testing on a TECA temperature control plate under controlled temperature increase and decrease conditions (e.g., 1.0°C at 5-minute intervals) until a complete color change was observed. OD (cyan) measurements were taken at each temperature interval using a 504 series densitometer.

[0356] Solvent Compatibility: Each sample was evaluated after 14 days to determine whether the solvents had damaged the thermochromic pigments. After 14 days, the pigments in each of the solvents showed a color change as expected, appearing colorless at room temperature and changing to dark blue upon exposure to refrigeration temperatures.

[0357] Hysteresis Loop Performance: Stretched samples coated with aqueous flexographic ink and solvent-based screen printing ink (1.5 mil, wet) were placed on the surface of the TECA temperature control page at 9°C and left for 30 minutes, after which OD (cyan) measurements were taken. The TECA temperature was increased in 1.0°C increments, and the sample OD values ​​were measured after 5 minutes at each test temperature. Overall, the 1.5 mil (wet) solvent-based screen printing ink applied to 2059 paper label material provides a The coating is significantly heavier than multiple layers of water-based flexographic ink. Furthermore, coatings prepared using the 3601ft / 4.3 BCM anilox exhibit the same color change behavior as coatings prepared using the 1601ft / 12.0 BCM anilox. All samples tested for color change under controlled temperature rise and fall conditions showed performance within the desired target specification: colorless (light blue) between 16.5°C and 19.5°C upon warming from refrigeration, and reappearance of the dark blue color at or below 12°C. All samples exhibited hysteresis loop behavior as expected, but the ACE samples showed a sharper color change transition (i.e., steeper hysteresis curves) than ink containing Glitter Unique pigment or LCR Hallcrest.

[0358] Temperature cycling: Three sections of the stretched samples (1.5 mil stretch, Bird bar, of solvent screen printing ink made with ACE pigment) were placed in a Darwin Refrigerated Incubator at 5°C ± 3°C and left under cold conditions for 30 minutes. After the initial 30 minutes of refrigeration, the samples (e.g., Sample A, Sample B, and Sample C) were exposed to different cycling conditions. Sample A was left continuously under refrigeration (in the Darwin Incubator at 5°C), Sample B was cycled between refrigeration (at 5°C) and room temperature, maintaining it for 30 minutes in each condition, and Sample C was cycled between refrigeration (at 5°C) and 37°C, maintaining it for 30 minutes in each condition.

[0359] The cycling test was conducted for a total of 48 hours, with one overnight exposure to refrigeration and another overnight exposure to a temperature above the established activation temperature (i.e., room temperature or 37°C). Throughout the cycling test, all samples exhibited an acceptable visual color change, with the appearance of a dark blue color under refrigeration and the disappearance of the blue color upon warming to room temperature or to 37°C on the TECA. After 48 hours, the samples were tested for their color response under controlled conditions of temperature increase and decrease on the TECA.

[0360] Conclusions: The ACE thermochromic pigment, reversible at 18°C ​​and left at room temperature for 2 weeks dissolved in IPA, water, and EEP, showed a color change as expected, appearing colorless at room temperature and turning dark blue upon exposure to refrigeration. This preliminary evaluation confirmed that the microcapsule shell material is not negatively affected by exposure to these solvents. Furthermore, tests Controlled temperature increases / decreases performed on reversible blue-to-colorless inks at 18°C ​​(solvent-based screen printing and water-based flexographic inks) containing pigments from different suppliers confirmed the hysteresis loop performance characteristics of the reversible thermochromic material. Overall, the 1.5 mil solvent-based screen printing ink applied as a coating to 2059 paper label material provided a much heavier coating and, consequently, greater color contrast between the dark blue and colorless states than the multiple (6x) layers of the water-based flexographic ink. The results also showed that inks made with the ACE pigment exhibit a sharper color change transition (i.e., a steeper hysteresis curve) than inks containing the pigment from Glitter Unique or LCR Hallcrest.

[0361] After 48 hours of temperature cycling between refrigeration and room temperature and refrigeration and 37°C, all the samples tested showed no major differences in hysteresis loop performance. All samples subjected to temperature cycling exhibited similar performance to the control sample (without temperature cycling) and the sample stored continuously under refrigerated conditions for 48 hours.

[0362] * * *

[0363] It should be understood that various changes and modifications to the exemplary embodiments described herein will be obvious to a person skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of this subject matter and without diminishing its intended advantages. It is therefore understood that such changes and modifications are covered by the scope of the invention.

[0364] Many modifications and other embodiments of the invention described herein will occur to a person skilled in the art to whom these inventions relate, once they have benefited from the lessons learned from the preceding descriptions and accompanying drawings. Therefore, it is understood that the inventions are not limited to the specific embodiments disclosed, and that modifications and other embodiments are understood to be included within the scope of the invention. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for the purpose of limitation.

[0365] The invention relates to: 1. Thermal paper for environmental exposure prepared by a process comprising the following steps: the addition of reversible thermochromic pigments to an acrylic binder and a water-based solvent to create a thermochromic formulation reversible, the thermochromic formulation being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 18°C; and the coating of the thermal paper by the reversible thermochromic formulation. 2. Thermal paper for environmental exposure according to 1, in which the acrylic binder is a clear, viscous acrylic resin solution. 3. Thermal paper for environmental exposure according to 1, wherein the thermochromic formulation comprises one of 26 percent by weight of thermochromic pigments, 24.5 percent by weight of thermochromic pigments and 24 percent by weight of thermochromic pigments. 4. Thermal paper for environmental exposure according to 1, wherein the thermochromic formulation comprises one of 44 percent by weight of acrylic binder, 47 percent by weight of acrylic binder and 49 percent by weight of acrylic binder. 5. Thermal paper for environmental exposure according to 1, in which the thermochromic formulation has a viscosity (cps) between 150 cps and 300 cps. 6. Thermal paper for environmental exposure according to 1, in which the thermochromic formulation has a viscosity (cps) between 150 cps and 300 cps. 7. Thermal paper for environmental exposure according to 1, in which the thermochromic formulation has a flow stress between 3.0 dynes / cm2 and 17 dynes / cm2. 8. Data shape for environmental exposure prepared by a process comprising the following steps: imaging thermal paper with a data shape through at least one layer of a reversible thermochromic ink to create the data shape for environmental exposure, the reversible thermochromic ink being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 18°C. 9. Data form for environmental exposure according to 8, in which reversible thermochromic ink is formed by mixing thermochromic pigments with an acrylic binder and an aqueous-based solvent. 10. Data form for environmental exposure according to 8, in which the acrylic binder is a clear, viscous acrylic resin solution. 11. Data form for environmental exposure according to 8, in which the thermochromic ink comprises one of 26 percent by weight of pigments thermochromic, 24.5 percent by weight of thermochromic pigments and 24 percent by weight of thermochromic pigments. 12. Data form for environmental exposure according to 8, in which the thermochromic ink comprises one of 44 percent by weight of acrylic binder, 47 percent by weight of acrylic binder and 49 percent by weight of acrylic binder. 13. Data form for environmental exposure according to 8, in which the thermochromic ink has a viscosity (cps) between 150 cps and 300 cps. 14. Data form for environmental exposure according to 8, in which the thermochromic ink has a viscosity (cps) between 150 cps and 300 cps. 15. Data form for environmental exposure according to 8, in which the thermochromic ink has a flow stress between 3.0 dynes / cm2 and 17 dynes / cm2. 16. Label including: a flexible substrate, the flexible substrate comprising a first face and a second face, the first side being an adhesive, the second side being configured to be printed with a first visible mark, and the second side having a second overlapping mark, printed, the overlapping mark being configured to change opacity below a first transition temperature to obscure the visible mark. 17. Label according to 16, in which the overlapping mark changes opacity, from opaque to transparent, at a second transition temperature, the second transition temperature being the same as the first transition temperature. 18. Label according to 16, in which the overlapping mark changes from opaque to transparent at a second transition temperature, the second transition temperature being higher than the first transition temperature. 19. Label according to 17 or 18, in which the adhesive is configured to fix the label to a bottle, and the second transition temperature is configured to change opacity when a liquid inside the bottle reaches 18°C. 20. Label according to 16, in which the flexible substrate comprises a thermochromic layer configured to be printed by a thermal printer at an imaging temperature. 21. Label according to 16, wherein the flexible substrate comprises a top coating configured to be printed by a thermal printer. 22. Label according to 16, in which the visible mark is light blue and the overlapping mark, when opaque, is dark blue. 23. Label according to 16, wherein the flexible substrate is a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead, the thermal paper substrate having an imaging temperature and being adapted to change color when heated by the thermal printhead heated to or above the imaging temperature. 24. Label according to 23, further comprising an environmental exposure indicator disposed on the thermal paper substrate, the environmental exposure indicator comprising an environmental exposure indicator material configured to change color state in response to exposure to temperature above a predetermined threshold temperature, which is below the imaging temperature. 25. Label according to 24, in which the indicator for exposure to the environment is the overlapping mark. 26. Label according to 24, in which the indicator material for exposure to the environment is a dye encapsulated in a matrix. 27. Label according to 24 to 26, in which the indicator material for environmental exposure is chosen from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 28. Label according to 27, in which the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; and (h) an indicator material configured to change color state in response to exposure to moisture. 29. Label according to 27, wherein the indicator material for environmental exposure is (a), and the flexible substrate is configured to image a data form, preferably a barcode, on the flexible substrate at an imaging temperature above the threshold temperature without the indicator material for environmental exposure changing color state. 30. Label according to 29, in which the data form is the visible mark. 31. Label according to 27, in which the indicator material for exposure to the environment is (a), and the indicator material for exposure to the environment is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range chosen in the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes. 32. Label according to 24 to 31, wherein the threshold temperature is in the range chosen in the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C. 33. Label according to 32, in which the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C. 34. Label according to 32, in which the threshold temperature is 40°C. 35. Label according to 24 to 34, in which the print head has a temperature of heated heat transfer which is in the range chosen in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C. 36. Label according to 24 to 34, wherein the print head is configured to heat at least a part of the label to a heated heat transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C and about 210 to 220°C. 37. Label according to 24 to 36, wherein the indicator material for environmental exposure further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetyl, an alkane, a wax, an ester or combinations thereof. 38. Label according to 24 to 37, wherein the indicator material for environmental exposure has a particle size in the range selected from the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns. 39. Label according to 38, in which the indicator material for exposure to the environment has a particle size between 400 nm and 600 nm. 40. Label according to 24 to 39, wherein the indicator material for environmental exposure has a concentration, in a layer applied to the material for direct thermal printing, in the range selected from the group consisting of about 10 to 60% w / w, about 20 to 60% w / w, about 25 to 60% w / w, about 30 to 60% w / w, about 35 to 60% w / w, about 40 to 60% w / w, about 30 to 60% w / w, about 30 to 55% w / w, about 30 to 50% w / w, about 30 to 45% w / w, about 40 to 55% w / w, about 40 to 50% w / w, and about 45 to 50% w / w. 41. Label according to 27, wherein the indicator material for environmental exposure is (c) and the second lower temperature threshold is in the range chosen from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C. 42. Label according to 24, in which the indicator material for exposure to the environment is disposed on the thermal paper substrate in the form of a thick suspension of ink. 43. Label according to 42, in which the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet. 44. Label according to 42, in which the thick ink suspension is configured to change color state from black to colorless above the threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C. 45. Label according to 42, in which the thick ink suspension is configured to change color state from colorless to black above the threshold temperature of 65°C. 46. ​​Label according to 42, in which the thick ink suspension is configured to change color state from colorless to magenta above the threshold temperature of 85°C. 47. Label according to 24, in which the indicator material for environmental exposure is disposed on the thermal paper substrate in the form of an SCC emulsion. 48. Label according to 47, in which the SCC emulsion is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet. 49. Label according to 47, in which the SCC emulsion is configured to change color state from opaque white to colorless above the threshold temperature of 40°C. 50. Thermal transfer tape for environmental exposure, prepared by a process comprising the steps of: add reversible thermochromic pigments to an acrylic binder and an IPA solvent matrix to create a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from black to colorless in response to exposure to temperature above a threshold temperature of 35°C; and coat a blank thermal transfer ribbon with the reversible thermochromic formulation. 51. Data form for environmental exposure, prepared by a process comprising the following steps: the performance of a thermal printing operation on a thermal transfer ribbon to print a data form onto a printing substrate, thereby creating the data form for exposure to the environment, the thermal transfer ribbon comprising a layer of a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from black to colorless in response to exposure to temperature above a threshold temperature of 35°C. 52. Data form for environmental exposure according to 51, wherein the reversible thermochromic formulation comprises reversible thermochromic pigments, an acrylic binder and an IPA solvent matrix. 53. Thermal transfer tape for environmental exposure, prepared by a process comprising the following steps: the addition of reversible thermochromic pigments to an acrylic binder and an IPA solvent matrix to create a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 12°C; and the coating of a blank thermal transfer ribbon with the reversible thermochromic formulation. 54. Data form for environmental exposure, prepared by a process comprising the following steps: the performance of a thermal printing operation on a thermal transfer ribbon to print a data form onto a printing substrate, thereby creating the data form for exposure to the environment, the thermal transfer ribbon comprising a layer of a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 12°C. 55. Data form for environmental exposure according to 20, wherein the reversible thermochromic formulation comprises reversible thermochromic pigments, an acrylic binder and an IPA solvent matrix. 56. Thermal paper for environmental exposure, prepared by a process comprising the following steps: the coating of thermal paper with at least one layer of a thick suspension of semi-reversible thermochromic ink, at least one layer having a thickness of 1.5 mils when wet, and the thick suspension of semi-reversible thermochromic ink being configured to change color state from black to colorless above a threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C. 57. Data form for environmental exposure, prepared by a process comprising the following steps: imaging thermal paper with a data shape through at least one layer of a semi-reversible thermochromic ink to create the data shape for environmental exposure, the semi-reversible thermochromic ink being configured to change color state from black to colorless above a threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C, and the imaging process not being affected by at least one layer of the semi-reversible thermochromic ink. 58. Data form for environmental exposure according to 57, wherein at least one layer of semi-reversible thermochromic ink is applied as a coating on thermal paper in the form of a thick suspension of semi-reversible thermochromic ink, the at least one layer having a thickness of 1.5 mil when wet. 59. Thermal paper for environmental exposure, prepared by a process comprising the following steps: coat the thermal paper with at least one layer of a thick suspension of irreversible thermochromic ink, at least one layer having a thickness of 1.5 mils when wet, and the thick suspension of irreversible thermochromic ink being configured to change color state from colorless to black above a threshold temperature of 65°C. 60. Data form for environmental exposure, prepared by a process comprising the following steps: to image a thermal paper with a data shape through at least one layer of an irreversible thermochromic ink to create the data shape for exposure to the environment, the irreversible thermochromic ink being configured to change color state from colorless to black above a threshold temperature of 65°C, and the imaging process not being affected by at least one layer of irreversible thermochromic ink. 61. Data form for environmental exposure according to 60, wherein at least one layer of irreversible thermochromic ink is applied as a coating on thermal paper in the form of a thick suspension of irreversible thermochromic ink, the at least one layer having a thickness of 1.5 mil when wet. 62. Thermal paper for environmental exposure, prepared by a process comprising the following steps: the coating of thermal paper with at least one layer of a thick suspension of irreversible thermochromic ink, the layer having a thickness of 1.5 mil when wet, and the thick suspension of irreversible thermochromic ink being configured to change color state from colorless to magenta above a threshold temperature of 85°C. 63. Data form for environmental exposure, prepared by a process comprising the following steps: imaging of thermal paper with a data shape through at least one layer of an irreversible thermochromic ink to create the data shape for environmental exposure, the irreversible thermochromic ink being configured to change color state from colorless to magenta above a threshold temperature of 85°C, and the imaging process not being affected by at least one layer of the irreversible thermochromic ink. 64. Data form for environmental exposure according to 63, wherein at least one layer of irreversible thermochromic ink is applied to thermal paper in the form of a thick suspension of irreversible thermochromic ink, the at least one layer having a thickness of 1.5 mil when wet. 65. Thermal paper for environmental exposure, prepared by a process comprising the following steps: the coating of the thermal paper by a layer of an SCC emulsion, the layer having a thickness of 1.5 mil when wet, and the SCC emulsion being configured to change color state from opaque white to colorless in response to exposure to temperature above a threshold temperature of 40°C. 66. Thermal paper for environmental exposure according to 65, wherein the thermal paper is printed by submersion in black before being coated with the SCC emulsion layer. 67. Data form for environmental exposure, prepared by a process comprising the steps of: image a thermal paper with a data shape through a layer of an SCC emulsion to create the data shape for environmental exposure, the SCC emulsion being configured to change color state from opaque white to colorless in response to exposure to temperature above a threshold temperature of 40°C, and the imaging process not being affected by the SCC emulsion layer. 68. Data form for environmental exposure according to 67, wherein the SCC emulsion is applied as a coating on the thermal paper to form the layer, and the layer having a thickness of 1.5 mil when wet. 69. Direct thermal printer material comprising an environmental exposure indicator material, including: a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead, the thermal paper substrate having an imaging temperature and being capable of changing color when heated by the thermal printhead heated to or above the printing temperature; and an environmental exposure indicator disposed on the thermal paper substrate, the temperature exposure indicator comprising the environmental exposure indicator material configured to change color state in response to temperature exposure above a predetermined threshold temperature, which is below the printing temperature. 70. Material for direct thermal printer according to 69, wherein the indicator material for exposure to the environment is a dye encapsulated in a matrix. 71. Material for direct thermal printer according to 69 or 70, wherein the indicator material for environmental exposure is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 72. Direct thermal printing material according to 70, wherein the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; and (h) an indicator material configured to change color state in response to exposure to moisture. 73. Direct thermal printer material according to 71, wherein the environmental exposure indicator material is (a), and the direct thermal printer material is configured to image a data form, preferably a barcode, on the direct thermal printer material at a printing temperature above the threshold temperature without the environmental exposure indicator material changing color state. 74. Direct thermal printer material according to 71, wherein the environmental exposure indicator material is (a), and the environmental exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is within the range selected from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes. 75. Material for direct thermal printing according to 69 to 74, wherein the threshold temperature is within the range selected from the group constituted by approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C. 76. Material for direct thermal printer according to 75, wherein the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C. 77. Material for direct thermal printer according to 76, in which the threshold temperature is 40°C. 78. Direct thermal printer material according to 69 to 77, wherein the print head has a heated thermal transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C. 79. Direct thermal printer material according to 69 to 78, wherein the print head is configured to heat at least a portion of the direct thermal printer material to a heated heat transfer temperature which is within the range selected in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C and approximately 210 to 220°C. 80. Direct thermal printer material according to 69 to 79, wherein the environmental exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetyl, an alkane, a wax, an ester or combinations thereof. 81. Material for direct thermal printer according to 69 to 80, wherein the indicator material for environmental exposure has a particle size in the range selected from the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns. 82. Material for direct thermal printer according to 81, wherein the indicator material for exposure to the environment has a particle size between 400 nm and 600 nm. 83. Direct thermal printer material according to 69 to 82, wherein the indicator material for environmental exposure has a concentration, in a layer applied to the direct thermal printer material, in the range selected from the group consisting of about 10 to 60% w / w, about 20 to 60% w / w, about 25 to 60% w / w, about 30 to 60% w / w, about 35 to 60% w / w, about 40 to 60% w / w, about 30 to 60% w / w, about 30 to 55% w / w, about 30 to 50% w / w, about 30 to 45% w / w, about 40 to 55% w / w, about 40 to 50% w / w, and about 45 to 50% w / w. 84. Material for direct thermal printer according to 69, in which the indicator material for exposure to the environment is (c) and the second lower temperature threshold is in the range chosen in the group consisting of < 4° C, < 0° C, < 5° C, < -10° C and < -15° C. 85. Material for direct thermal printer according to 69, in which the indicator material for exposure to the environment is disposed on the thermal paper substrate in the form of a thick ink suspension. 86. Direct thermal printer material according to 85, in which the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet. 87. Material for direct thermal printer according to 85, in which the thick ink suspension is configured to change color state from black to colorless above the threshold temperature of 55°C, and to maintain the changed color state until the temperature falls below a second lower temperature threshold of 0°C. 88. Material for direct thermal printer according to 69, in which the indicator material for exposure to the environment is disposed on the thermal paper substrate in the form of a thick ink suspension. 89. Direct thermal printer material according to 88, in which the thick ink suspension is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet. 90. Material for direct thermal printer according to 88, in which the thick ink suspension is configured to change color state from colorless to black above the threshold temperature of 65°C. 91. Material for direct thermal printer according to 88, in which the thick ink suspension is configured to change color state from colorless to magenta above the threshold temperature of 85°C. 92. Material for direct thermal printer according to 69, in which the indicator material for exposure to the environment is disposed on the thermal paper substrate in the form of an SCC emulsion. 93. Direct thermal printer material according to 92, in which the SCC emulsion is disposed on the thermal paper substrate in a layer having a thickness of 1.5 mil when wet. 94. Material for direct thermal printer according to 92, in which the SCC emulsion is configured to change color state from opaque white to colorless above the threshold temperature of 40°C. 95. Thermal transfer ribbon, comprising: a support substrate; an indicator material for exposure to a temperature threshold, configured to change color state in response to exposure to temperature above or below a threshold temperature; a bonding layer positioned to couple the temperature exposure indicator material to the support substrate and configured to release the temperature exposure indicator material onto a printable support when heated by a print head, the bonding layer having a melting temperature above the threshold temperature and having a stronger adhesion to the print support than the adhesion of the bonding layer to the support substrate. 96. Thermal transfer ribbon according to 95, further comprising an anti-stick coating coupling the bonding layer to the support substrate. 97. Thermal transfer ribbon according to 96, in which the non-stick coating is a heat-sensitive wax. 98. Thermal transfer ribbon according to 95 to 97, wherein the indicator material for exposure to a temperature threshold is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 99. Thermal transfer ribbon according to 98, wherein the indicator material for exposure to a temperature threshold is (a), and the indicator material for exposure to a temperature threshold is configured to be applied to the printing substrate when the bonding layer has melted by the print head having a printing temperature above the melting temperature without the indicator material for exposure to a temperature threshold changing color state. 100. Thermal transfer ribbon according to 98, wherein the indicator material for exposure to a temperature threshold is (a), and the indicator material for exposure to a temperature threshold is configured to change color state in response to exposure to a temperature above the threshold temperature for a period that is in the range chosen in the group consisting of about 30 seconds to 5 minutes, about 1 minute to 5 minutes, about 2 minutes to 4 minutes, and about 2 minutes to 3 minutes. 101. Thermal transfer ribbon according to 95 to 100, wherein the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof. 102. Thermal transfer ribbon according to 95 to 101, in which the bonding layer comprises an adhesive which is solvent-based, aqueous emulsion-based, or water-soluble. 103. Thermal transfer ribbon according to 102, wherein the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A. 104. Thermal transfer ribbon according to 102 or 103, wherein the adhesive has a melting temperature that is within the range selected in the group constituted by about 50 to 110°C, about 60 to 110°C, about 70 to 110°C, about 80 to 110°C, about 90 to 110°C, about 100 to 110°C, about 50 to 100°C, about 60 to 100°C, about 70 to 100°C, about 80 to 100°C, about 90 to 100°C, about 70 to 90°C, and about 80 to 90°C. 105. Thermal transfer ribbon according to 95 to 104, in which the threshold temperature is in the range chosen in the group consisting of about -20 to 70°C, about 30 to 70°C, about 30 to 50°C, about 40 to 50°C, about 20 to 40°C, about 20 to 30°C, about 25 to 35°C, about 30 to 35°C, about 32.5 to 35°C and about 34 to 36°C. 106. Thermal transfer ribbon according to 105, wherein the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C. 107. Thermal transfer ribbon according to 106, in which the threshold temperature is 40°C. 108. Thermal transfer ribbon according to 95 to 107, in which the print head has a heated thermal transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C. 109. Thermal transfer ribbon according to 95 to 108, wherein the print head is configured to heat at least a portion of the thermal transfer ribbon to a heated thermal transfer temperature which is within the range selected in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C and approximately 210 to 220°C. 110. Thermal transfer ribbon according to 95 to 109, wherein the indicator material for exposure to a temperature threshold further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester or combinations thereof. 111. Thermal transfer ribbon according to 95 to 110, wherein the indicator material for exposure to a temperature threshold has a particle size in the range selected from the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns. 112. Thermal transfer ribbon according to 111, in which the indicator material for exposure to a temperature threshold has a particle size between 400 nm and 600 nm. 113. Thermal transfer ribbon according to 95 to 112, wherein the indicator material for exposure to a temperature threshold has a concentration, in the bonding layer, in the range selected from the group consisting of about 10 to 60% w / w, about 20 to 60% w / w, about 25 to 60% w / w, about 30 to 60% w / w, about 35 to 60% w / w, about 40 to 60% w / w, about 30 to 60% w / w, about 30 to 55% w / w, about 30 to 50% w / w, about 30 to 45% w / w, about 40 to 55% w / w, about 40 to 50% w / w, and about 45 to 50% w / w. 114. Thermal transfer ribbon according to 95 to 113, in which the substrate has a thickness of about 4 microns to about 6 microns. 115. Thermal transfer ribbon according to 95 to 114, in which the bonding layer has a thickness of about 2 microns to about 50 microns. 116. Thermal transfer ribbon according to 95, wherein the indicator material for exposure to a temperature threshold is (c) and the second lower temperature threshold is in the range chosen from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C. 117. Thermal transfer ribbon according to 95 to 116, wherein the bonding layer comprises at least one additive configured to increase the thermal capacity of the bonding layer. 118. Thermal transfer ribbon according to 95 to 117, wherein the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester and triacetin. 119. Thermal transfer ribbon according to 95, wherein the indicator material for exposure to a temperature threshold is (a) and does not change color state when released onto the printable substrate. 120. Thermal transfer ribbon according to 95, in which a portion of the bonding layer is configured to release itself from the support substrate onto the printable substrate where the portion is heated by a heating element of the print head. 121. Thermal transfer ribbon according to 95, in which the temperature threshold exposure indicator material is configured to change color state from black to colorless in response to exposure to a temperature above the threshold temperature of 35°C. 122. Thermal transfer ribbon according to 121, in which the bonding layer is formed of an acrylic binder and an IPA solvent matrix. 123. Thermal transfer ribbon according to 121, wherein the support substrate is a blank thermal transfer ribbon. 124. Thermal transfer ribbon according to 95, in which the temperature threshold exposure indicator material is configured to change color state from blue to colorless in response to exposure to a temperature above the threshold temperature of 12°C. 125. Thermal transfer ribbon according to 124, in which the bonding layer is formed of an acrylic binder and an IPA solvent matrix. 126. Thermal transfer ribbon according to 125, wherein the supporting substrate is a blank thermal transfer ribbon. 127. Direct thermal label, comprising: a thermal paper substrate configured to be printed by a direct thermal printing process with a heated thermal printhead, the thermal paper substrate having a printing temperature and being capable of changing color when heated by the heated thermal printhead to or above the printing temperature; a temperature exposure indicator disposed on the thermal paper substrate, the temperature exposure indicator comprising the temperature exposure indicator material configured to change color state in response to temperature exposure above a predetermined threshold temperature, which is below the printing temperature; and an image data form on the thermal paper substrate at or above the printing temperature without the indicator material for temperature exposure changing color state. 128. Direct thermal label according to 127, wherein the indicator material for exposure to temperature is a dye encapsulated in a matrix. 129. Direct thermal label according to 127 or 128, wherein the indicator material for exposure to temperature is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second lower temperature threshold; And (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 130. Direct thermal label according to 128, wherein the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; and (h) an indicator material configured to change color state in response to exposure to moisture. 131. Direct thermal label according to 127, wherein the indicator for temperature exposure is configured to reveal a barcode symbol in response to temperature exposure above the predetermined threshold temperature. 132. Direct thermal label according to 131, wherein the indicator for temperature exposure is configured to mask the barcode symbol in response to exposure to temperature below the predetermined threshold temperature. 133. Direct thermal label according to 132, wherein the indicator material for temperature exposure is configured to change color state in response to exposure to a temperature above the threshold temperature for a period that is within the range selected in the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes. 134. Direct thermal label according to 133, wherein the threshold temperature is in the range selected in the group consisting of about -20 to 70°C, about 30 to 70°C, about 30 to 50°C, about 40 to 50°C, about 20 to 40°C, about 20 to 30°C, about 25 to 35°C, about 30 to 35°C, about 32.5 to 35°C, and about 34 to 36°C. 135. Direct thermal label according to 134, wherein the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C. 136. Direct thermal label according to 135, in which the threshold temperature is 40°C. 137. Label configured to indicate exposure to temperature above a threshold temperature, the label comprising: a substrate with a first face and a second face, the first face comprising a printable area and an irreversible thermochromic indicator material configured to change color state in response to exposure to a temperature above the threshold temperature; an adhesive layer adjacent to the second face; and a coating layer adjacent to the first face, the indicator material being between the coating layer and the substrate. 138. Label according to 137, in which the printable area comprises a direct thermochromic material. 139. Label according to 137, in which the coating layer is a resin of a thermal transfer ribbon. 140. Label according to 137, in which the coating layer is a thermally printed overlayer. 141. Label according to 137, in which the coating is a varnish. 142. Label according to 137, in which the printable area includes the material irreversible thermochromic indicator. 143. A process for manufacturing a thermal transfer ribbon, the process comprising: provide a supporting substrate; provide a temperature exposure indicator material configured to change color state in response to exposure to a temperature above a threshold temperature; and coupling the temperature exposure indicator material to the support substrate via a bonding layer, the bonding layer being configured to release the temperature exposure indicator material onto a support printable when heated by a print head, the bonding layer having a melting temperature above the threshold temperature. 144. A method according to 143, in which the thermal transfer ribbon is configured such that when the thermal transfer ribbon is heated by the print head of a thermal printer on one face of the support substrate opposite the temperature indicator material, so as to melt the bonding layer, the temperature indicator material is released from the support substrate and applied to the printable support. 145. The method according to 143, further comprising: to provide a non-stick coating coupling the bonding layer to the supporting substrate; and coat the support substrate with the non-stick coating before coating the support tape with the bonding layer, the non-stick coating being configured to couple the bonding layer to the support tape. 146. A process according to 145, wherein the non-stick coating is a heat-sensitive wax. 147. A method according to 143 to 146, wherein the indicator material for temperature exposure is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 148. A method according to 146, wherein the indicator material for exposure to temperature is (a), and the indicator material for exposure to temperature is configured to be applied to the printing substrate when the bonding layer is melted by the print head having a printing temperature above the melting temperature without the temperature exposure indicator material changing color state. 149. Method according to 146, wherein the temperature exposure indicator material is (a), and the temperature exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range chosen in the group consisting of about 30 seconds to 5 minutes, about 1 minute to 5 minutes, about 2 minutes to 4 minutes, and about 2 minutes to 3 minutes. 150. A process according to 143 to 149, wherein the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof. 151. A process according to 143 to 150, wherein the bonding layer comprises an adhesive that is solvent-based, aqueous emulsion-based, or water-soluble. 152. A process according to 151, wherein the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, carnauba wax, candelilla wax, hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A. 153. Process according to 151 or 152, wherein the adhesive has a melting temperature which is in the range chosen in the group consisting of about 50 to 110°C, about 60 to 110°C, about 70 to 110°C, about 80 to 110°C, about 90 to 110°C, about 100 to 110°C, about 50 to 100°C, about 60 to 100°C, about 70 to 100°C, about 80 to 100°C, about 90 to 100°C, about 70 to 90°C, and about 80 to 90°C. 154. A process according to 151 to 153, further comprising: dissolving the adhesive and the temperature exposure indicator material in a solvent to form a solution; Apply the solution to the support substrate; and dry the solution to form the bonding layer. 155. A process according to 143 to 154, wherein the threshold temperature is within the range selected from the group consisting of approximately -20 to 70°C, approximately 30 to 70°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C. 156. Method according to 155, wherein the threshold temperature is one of 35°C, 40°C, 45°C, 50°C and 60°C. 157. Process according to 156, in which the threshold temperature is 40°C. 158. Method according to 143 to 157, wherein the print head has a heated heat transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C. 159. Method according to 143 to 158, wherein the print head is configured to heat at least a portion of the thermal transfer ribbon to a heated thermal transfer temperature that is in the range selected in the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C and approximately 210 to 220°C. 160. A process according to 143 to 159, wherein the temperature exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester, or combinations thereof. 161. A method according to 143 to 160, wherein the indicator material for temperature exposure has a particle size in the range selected from the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns. 162. Method according to 161, wherein the indicator material for exposure to temperature has a particle size between 400 nm and 600 nm. 163. A process according to 143 to 162, wherein the indicator material for exposure to temperature has a concentration, in the bonding layer, within the range chosen in the group consisting of approximately 10 to 60% by weight, approximately 20 to 60% by weight / weight, approximately 25 to 60% by weight / weight, approximately 30 to 60% by weight / weight, approximately 35 to 60% by weight / weight, approximately 40 to 60% by weight / weight, approximately 30 to 60% by weight / weight, approximately 30 to 55% by weight / weight, approximately 30 to 50% by weight / weight, approximately 30 to 45% by weight / weight, approximately 40 to 55% by weight / weight, approximately 40 to 50% by weight / weight, and approximately 45 to 50% by weight / weight. 164. Process according to 143 to 163, wherein the substrate has a thickness of about 4 microns to about 6 microns. 165. Process according to 143 to 164, in which the bonding layer has a thickness of about 2 microns to about 50 microns. 166. Method according to 143, wherein the indicator material for exposure to temperature is (c) and the second lower temperature threshold is in the range chosen in the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C. 167. A process according to 143 to 166, wherein the bonding layer comprises at least one additive configured to increase the thermal capacity of the bonding layer. 168. Process according to 143 to 167, wherein the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester and triacetin. 169. A method for use with a thermal transfer ribbon having a support substrate and a temperature exposure indicator material coupled to the substrate via a bonding layer, the method comprising: receive a trace of a temperature indicator, the temperature indicator being formed by the temperature exposure indicator material of the bonding layer, the temperature exposure indicator material being configured to change color state in response to exposure to temperature above or below a predetermined threshold temperature; and heat the bonding layer with a print head to a respective temperature at or above a bonding layer melting temperature, causing the bonding layer to transfer from the thermal transfer ribbon to a printing surface to print the temperature indicator according to the received trace, the bonding layer melting temperature being above the threshold temperature. 170. Method according to 169, wherein the thermal transfer ribbon further comprises an anti-stick coating coupling the bonding layer to the support substrate. 171. Process according to 170, wherein the non-stick coating is a heat-sensitive wax. 172. A method according to 169 to 171, wherein the indicator material for exposure to temperature is chosen from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 173. Method according to 172, wherein the indicator material for exposure to temperature is (a), and the transfer of the bonding layer from the support substrate to the printing surface, by the print head, is carried out without the irreversible thermochromic indicator material changing color state. 174. Method according to 172, wherein the temperature exposure indicator material is (a), and the temperature exposure indicator material is configured to change color state in response to exposure to temperature above the threshold temperature for a period that is in the range chosen in the group consisting of about 30 seconds to 5 minutes, about 1 minute to 5 minutes, about 2 minutes to 4 minutes, and about 2 minutes to 3 minutes. 175. Method according to 169 to 174, further comprising printing a barcode symbol on the printing surface. 176. Process according to 169 to 175, in which the printing surface is a product surface. 177. Method according to 169 to 176, further comprising aligning the temperature indicator trace with a designated space on the printing surface. 178. Method according to 169, further comprising: receive a label which includes a computer-readable index encoding a data code word applied to it, the printing surface being the label; locate the computer-readable index; and determine a print position for the temperature exposure indicator based on a position of the computer-readable index or the data code word encoded in the computer-readable index. 179. A process according to 169 to 178, wherein the support substrate is selected from the group consisting of polyester, polyethylene, paper, printable poly(ethylene terephthalate) ("PET"), oriented polypropylene ("OPP"), and combinations thereof. 180. A process according to 169 to 179, wherein the bonding layer comprises an adhesive that is solvent-based, aqueous emulsion-based, or water-soluble. 181. A process according to 180, wherein the adhesive comprises at least one material selected from the group consisting of an aqueous emulsion adhesive, an acrylic polymer or copolymer, an amine salt of an acrylic copolymer, a carnauba wax, a candelilla wax, a hydrocarbon wax, Neocryl A-1052, Neocryl BT-24, Neocryl B-818, Epotuf 91-263, Ottopol 25-50E, Ottopol 25-30, Joncryl 682 and Joncryl 538A. 182. Process according to 180 or 181, wherein the adhesive has a melting temperature which is in the range chosen in the group consisting of about 50 to 110°C, about 60 to 110°C, about 70 to 110°C, about 80 to 110°C, about 90 to 110°C, about 100 to 110°C, about 50 to 100°C, about 60 to 100°C, about 70 to 100°C, about 80 to 100°C, about 90 to 100°C, about 70 to 90°C, and about 80 to 90°C. 183. A process according to 169 to 182, wherein the threshold temperature is in the range chosen in the group consisting of approximately -20 to 70 °C, approximately 30 to 70 °C, approximately 30 to 50 °C, approximately 40 to 50 °C, approximately 20 to 40 °C, approximately 20 to 30 °C, approximately 25 to 35 °C, approximately 30 to 35 °C, approximately 32.5 to 35 °C, and approximately 34 to 36 °C. 184. Method according to 183, wherein the threshold temperature is one of 35 °C, 40 °C, 45 °C, 50 °C and 60 °C. 185. Process according to 184, in which the threshold temperature is 40 °C. 186. Method according to 169 to 185, wherein the print head has a heated heat transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C, and about 210 to 220°C. 187. Method according to 169 to 186, wherein the print head is configured to heat at least a portion of the thermal transfer ribbon to a heated thermal transfer temperature which is in the range selected in the group consisting of about 150 to 300°C, about 175 to 275°C, about 200 to 250°C, about 210 to 250°C, about 220 to 250°C, about 230 to 250°C, about 240 to 250°C, about 210 to 240°C, about 210 to 230°C and about 210 to 220°C. 188. A process according to 169 to 187, wherein the temperature exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester, or combinations thereof. 189. A method according to 169 to 188, wherein the indicator material for temperature exposure has a particle size in the range selected from the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns. 190. Method according to 189, wherein the indicator material for exposure to temperature has a particle size between 400 nm and 600 nm. 191. A process according to 169 to 190, wherein the temperature-exposure indicator material has a concentration in the bonding layer within the range selected from the group consisting of approximately 10 to 60 wt%, approximately 20 to 60 wt%, approximately 25 to 60 wt%, approximately 30 to 60 wt%, approximately 35 to 60 wt%, approximately 40 to 60 % by weight, approximately 30 to 60% by weight, approximately 30 to 55% by weight, approximately 30 to 50% by weight, approximately 30 to 45% by weight, approximately 40 to 55% by weight, approximately 40 to 50% by weight, and approximately 45 to 50% by weight. 192. Process according to 169 to 191, in which the substrate has a thickness of about 4 microns to about 6 microns. 193. Process according to 169 to 192, in which the bonding layer has a thickness of about 2 microns to about 50 microns. 194. A process according to 169, wherein the indicator material for exposure to temperature is (c) and the second lower temperature threshold is in the range chosen from the group consisting of < 4° C, < 0° C, < -5° C, < -10° C and < -15° C. 195. A process according to 169 to 194, wherein the bonding layer comprises at least one additive configured to increase the thermal capacity of the bonding layer. 196. Process according to 169 to 195, wherein the bonding layer comprises a plasticizer from the group consisting of: glycerol, propylene glycol, polyethylene glycol ("PEG"), a phthalate ester, dibutyl sebacate, a citrate ester and triacetin. 197. A method for manufacturing a temperature-indicating printing material, comprising: to receive thermal paper material; and apply a thermochromic temperature indicator material to the thermal paper material, the thermochromic temperature indicator material being configured to change color state in response to reaching a temperature that is below the printing temperature of the thermal paper material. 198. Method according to 197, further comprising the application of a varnish or coating to the thermochromic temperature indicator material. 199. A process according to 197, wherein the thermal paper material is a direct thermal printing paper containing a thermochromic pigment configured to change color when the printing temperature is reached. 200. A process according to 197 to 199, wherein the printing temperature is in the range selected from the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C. 201. A process according to 197 to 200, wherein the temperature for the temperature indicator material is in the range selected from the group consisting of approximately 20 to 50°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C. 202. A method according to 197 to 201, wherein the indicator material for temperature exposure is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 203. A method according to 202, wherein the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; and (h) an indicator material configured to change color state in response to exposure to moisture. 204. Method for manufacturing a temperature exposure indicator comprising: receiving a thermal paper material to which a thermochromic temperature indicator has been applied, the thermochromic temperature indicator being configured to change color state above a threshold temperature; and printing on thermal paper material using a direct thermal printing process through the thermochromic temperature indicator using a thermal print head bringing parts of the thermal paper material to a printing temperature above the threshold temperature without triggering the color state change of the thermochromic temperature indicator. 205. A method according to 204, wherein the thermal paper material comprises a dye encapsulated in a matrix that is configured to change state when the printing temperature is reached. 206. A method according to 204 or 205, wherein the indicator material for exposure to temperature is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change its color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second, lower temperature threshold; and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time. 207. A method according to 206, wherein the group further consists of: (f) an indicator material configured to change color state in response to exposure to radiation; (g) an indicator material configured to change color state in response to exposure to light of a predetermined wavelength; and (h) an indicator material configured to change color state in response to exposure to moisture. 208. Machine-readable, non-transient medium storing code which, when executed by at least one processor, is configured to perform any one of the numbered processes.

Claims

Demands

1. A method for manufacturing a temperature-indicating printing material comprising the steps of: receiving a thermal paper material having a printing temperature, the thermal paper material being a direct thermal printing paper containing a thermochromic pigment configured to change color when the printing temperature is reached; applying a thermochromic temperature-indicating material to the thermal paper material, the thermochromic temperature-indicating material being configured to change color state in response to reaching a temperature that is lower than the printing temperature of the thermal paper material;and image a form of data on the direct thermal paper material at a printing temperature above the threshold temperature of the indicator material for temperature exposure, through the thermochromic temperature indicator material.

2. A method according to claim 1 comprising the preparation of thermal paper for environmental exposure comprising the steps of: adding reversible thermochromic pigments to an acrylic binder and an aqueous-based solvent to create a reversible thermochromic formulation, the thermochromic formulation being configured to change color state from blue to colorless in response to exposure to temperature above a threshold temperature of 18 °C; and coating the thermal paper with the reversible thermochromic formulation.

3. A method according to claim 2, wherein: (a) the acrylic binder is a clear, viscous acrylic resin solution; or (b) the thermochromic formulation comprises one of 26 percent by weight of thermochromic pigments, 24.5 percent by weight of thermochromic pigments, and 24 percent by weight of thermochromic pigments; or (c) the thermochromic formulation comprises one of 44 percent by weight of acrylic binder, 47 percent by weight of acrylic binder and 49 percent by weight of acrylic binder; or (d) the thermochromic formulation has a viscosity (cps) between 150 cps and 300 cps; or (e) the thermochromic formulation has a flow stress between 3.0 dynes / cm2 and 17 dynes / cm2.

4. A method according to claim 2 or 3, wherein the method further comprises: imaging the thermal paper with a data form through at least one layer of the reversible thermochromic pigment.

5. A method according to any one of claims 2 to 4, wherein the thermal paper further comprises: a flexible substrate, the flexible substrate comprising a first face and a second face, the first face being an adhesive, the second face being configured to be printed with a first visible mark, and the second face having a second overlapping printed mark, the overlapping mark being configured to change opacity below a first transition temperature to obscure the visible mark.

6. A method according to claim 5, wherein: (a) the overlapping mark changes opacity, from opaque to transparent, at a second transition temperature, the second transition temperature being the same as the first transition temperature; or (b) the overlapping mark changes from opaque to transparent at a second transition temperature, the second transition temperature being higher than the first transition temperature; or (c) the adhesive is configured to fix the paper to a bottle, and the second overlapping mark changes from opaque to transparent at a second transition temperature, the second transition temperature being configured to change opacity when a liquid inside the bottle reaches 18°C; or (d) the indicator material for environmental exposure is a dye encapsulated in a matrix.

7. A method according to claim 1, wherein the printing temperature is in the range selected from the group consisting of approximately 150 to 300°C, approximately 175 to 275°C, approximately 200 to 250°C, approximately 210 to 250°C, approximately 220 to 250°C, approximately 230 to 250°C, approximately 240 to 250°C, approximately 210 to 240°C, approximately 210 to 230°C, and approximately 210 to 220°C.

8. A method according to any one of claims 1 to 7, wherein the temperature for the temperature indicator material is in the range selected from the group consisting of approximately 20 to 50°C, approximately 30 to 50°C, approximately 40 to 50°C, approximately 20 to 40°C, approximately 20 to 30°C, approximately 25 to 35°C, approximately 30 to 35°C, approximately 32.5 to 35°C, and approximately 34 to 36°C.

9. A method according to any one of claims 1, 7 or 8, wherein the temperature exposure indicator material is selected from the group consisting of: (a) an irreversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (b) a reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature; (c) a reversible thermochromic indicator material configured to change color state in response to a temperature below the threshold temperature; (d) a semi-reversible thermochromic indicator material configured to change color state in response to a temperature above the threshold temperature, and to maintain the changed color state until the temperature falls below a second lower temperature threshold;and (e) an irreversible thermochromic indicator material configured to change color state in response to cumulative heat exposure over time.

10. A method according to any one of claims 1, 7, 8, or 9, further comprising the following step: printing on the thermal paper material using a direct thermal printing method by means of a thermochromic temperature indicator using a thermal print head bringing portions of the thermal paper material to reach a printing temperature above the threshold temperature without triggering the color state change of the thermochromic temperature indicator.

11. A method according to any one of claims 1, 7, 8, 9 or 10, wherein the temperature exposure indicator material is configured to change color state in response to temperature exposure above the threshold temperature for a period that is in the range chosen from the group consisting of approximately 30 seconds to 5 minutes, approximately 1 minute to 5 minutes, approximately 2 minutes to 4 minutes, and approximately 2 minutes to 3 minutes.

12. A method according to any one of claims 1 to 11, wherein the temperature exposure indicator material further comprises a leuco dye, a microencapsulated leuco dye, an SCC polymer, an aqueous-based SCC polymer emulsion, a diacetylene, an alkane, a wax, an ester, or combinations thereof.

13. A method according to any one of claims 1 to 12, wherein the temperature exposure indicator material has a particle size in the selected range within the group consisting of approximately 0.1 to 15 microns, approximately 0.1 to 10 microns, approximately 0.4 to 10 microns, approximately 0.4 to 10 microns, approximately 5 to 10 microns, approximately 6 to 10 microns, approximately 7 to 10 microns, approximately 8 to 10 microns, approximately 9 to 10 microns, approximately 1 to 9 microns, approximately 1 to 8 microns, approximately 1 to 7 microns, approximately 1 to 6 microns, approximately 1 to 5 microns, approximately 1 to 4 microns, approximately 1 to 3 microns, approximately 1 to 2 microns, approximately 3 to 7 microns, approximately 3 to 6 microns, approximately 3 to 5 microns, approximately 4 to 7 microns, and approximately 4 to 6 microns.

14. A method according to any one of claims 1 to 13, wherein the temperature exposure indicator is configured to reveal a barcode symbol in response to temperature exposure above the predetermined threshold temperature, and to conceal the barcode symbol in response to temperature exposure below the predetermined threshold temperature.

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