A thermal label and preparation method thereof

Abstract

The present invention relates to the field of label technology, and specifically to a thermal label and a preparation method thereof. The thermal label comprises a thermal layer and a base paper layer arranged in sequence from top to bottom, and the thermal layer is formed by coating a thermal coating. The thermal label strip is usually used for variable information printing applications. Compared with the thermal label paper on the market, the thermal label of the present invention has good oil resistance and light resistance after printing, can be used or stored for a long time after printing, and also has better friction resistance and heat friction resistance, can be used as a cargo label, and can be adapted to high-speed printing, and has better printing clarity. The preparation method of the thermal label has a simple process and is easy to control in operation, which is conducive to large-scale industrial production. The thermal label obtained has stable quality and excellent comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the technical field of labels, and in particular to a thermal label and a preparation method thereof. Background Art

[0002] Thermal label strips are often used for variable information printing applications, such as for admission tickets, logistics centers, and retail label applications. Applications include address labels, self-service weight scale labels, and labels for in-store pricing of food to provide product identification and variable information, such as logistics information, weight, price, or EAN barcodes, at the time of sale and during transportation and receiving operations. However, existing thermal labels tend to become blurred due to collisions between goods in trucks during transportation in the summer, and have poor wear resistance. At the same time, when thermal labels are in contact with non-volatile solvents such as plasticizers and oils contained in plastics for a long time, the printed image will disappear, and they have poor light and oil resistance, are not easy to store for a long time, and are very inconvenient to use. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a thermal label, which has good oil resistance and light resistance after printing and can be used or stored for a long time; it also has excellent friction resistance and heat friction resistance, and can be used as a cargo label; it can be adapted to high-speed printing, and has good printing clarity and strong practicality.

[0004] The preparation method of the thermal label of the present invention has simple process, easy controllable operation, is conducive to large-scale industrial production, and the prepared thermal label has stable quality. The printed thermal label has good oil resistance and light resistance, as well as excellent friction resistance and heat friction resistance. It can be adapted to high-speed printing, has good printing clarity, and has excellent comprehensive performance.

[0005] The object of the present invention is achieved through the following technical solution: A thermal label comprises a thermal layer and a base paper layer arranged in sequence from top to bottom, wherein the thermal layer is formed by coating a thermal coating.

[0006] The thermal label of the present invention comprises a thermal layer and a base paper layer arranged in sequence from top to bottom, and the thermal layer is formed by coating a thermal coating. The thermal label strip is generally used for variable information printing applications, and is applicable to various fields and has a wide range of applications. The thermal label has stable quality, and the printed thermal label has good oil resistance and light resistance. It can be used or stored for a long time after printing, and also has excellent friction resistance and heat friction resistance, so it is convenient to use as a cargo label. At the same time, it can be adapted to high-speed printing, and has good printing clarity and excellent comprehensive performance.

[0007] In the above technical solution, the thickness of the thermal layer is 1-2 μm, and the thickness of the base paper layer is 85-95 μm.

[0008] In the above technical solution, the thermosensitive coating comprises the following raw materials in parts by weight: 4-8 parts of colorless dye, 18-22 parts of developer, 8-12 parts of sensitizer, 10-30 parts of filler, 25-35 parts of adhesive, 5-8 parts of stabilizer and 4-6 parts of lubricant.

[0009] In the above technical solution, the thermal label develops images and texts through a thermal paper printer. When the temperature reaches 50-70°C, the colorless dye and the developer begin to react, and the thermal label will gradually develop color. The heating process is completed in the printer.

[0010] In the above technical scheme, each part of the adhesive comprises the following raw materials in parts by weight: 30-45 parts of dipentaerythritol pentaacrylate, 5-15 parts of modified polytetrafluoroethylene, 5-7 parts of urea-formaldehyde resin, 4-5 parts of diallyl phthalate, 5-7 parts of talc, 2-3 parts of photoinitiator, 3-12 parts of deionized water and 1-2 parts of emulsifier.

[0011] In the above technical solution, the preparation method of the adhesive comprises the following steps:

[0012] A1: Add emulsifier, modified polytetrafluoroethylene and deionized water into a reactor and mix and stir for 30 minutes to obtain a modified polytetrafluoroethylene dispersion;

[0013] A2: Add dipentaerythritol pentaacrylate, urea-formaldehyde resin, diallyl phthalate, talc and photoinitiator into the modified polytetrafluoroethylene dispersion and stir for 1-3 hours to obtain an adhesive.

[0014] In the above technical solution, the emulsifier is a mixture of CO-458 and OP-10 at a weight ratio of 1.8-2.2:1. The photoinitiator is a mixture of photoinitiator 184 and photoinitiator 907 at a weight ratio of 0.8-1.2:1.

[0015] In the above technical solution, the preparation method of the thermosensitive coating comprises the following steps: mixing and stirring the colorless dye, the developer, the sensitizer, the filler, the adhesive, the stabilizer and the lubricant for 1-3 hours in a dark environment to obtain the thermosensitive coating.

[0016] In the above technical solution, the colorless dye is 3-diethylamino-7-chlorofluoran; the developer is bisphenol S; the sensitizer is a benzenesulfonic acid amide compound; the filler is calcium carbonate; the stabilizer is dibenzoyl terephthalate; and the lubricant is paraffin.

[0017] In the above technical solution, the modified polytetrafluoroethylene comprises the following raw materials in parts by weight: 45-55 parts of polytetrafluoroethylene, 8-11 parts of zinc oxide-silicon dioxide sol and 2-3 parts of γ-methacryloxypropyltrimethoxysilane.

[0018] In the above technical solution, the preparation method of the modified polytetrafluoroethylene comprises the following steps:

[0019] B1: Add deionized water to polytetrafluoroethylene to prepare a polytetrafluoroethylene dispersion with a solid content of 65-75%;

[0020] B2: Add zinc oxide-silica sol, γ-methacryloxypropyltrimethoxysilane and polytetrafluoroethylene dispersion into the reactor and stir evenly, then maintain at 80-110°C and perform ultrasonic treatment for 1-3 hours. After natural cooling, wash the precipitate in the reactor with distilled water and anhydrous ethanol by suction filtration for 2-3 times respectively, then put it into a forced air drying oven and dry it for 12 hours. Grind the dried powder for later use;

[0021] B3: Add the ground powder into a crucible, and then transfer it to a sintering furnace protected by nitrogen. The sintering temperature is 550-650°C and the sintering time is 30-45 minutes. After heating is completed and naturally cooled, modified polytetrafluoroethylene can be obtained.

[0022] In the above technical solution, in step B2, the frequency of ultrasonic treatment is 50-5000 Hz.

[0023] In the above technical scheme, the preparation method of the zinc oxide-silicon dioxide sol includes the following steps: dissolving zinc acetate dihydrate in anhydrous ethanol at 45-55°C, then slowly adding diethanolamine and ethyl orthosilicate to the solution and stirring continuously for 0.8-1.2h to obtain zinc oxide-silicon dioxide sol.

[0024] In the above technical solution, the molar ratio of zinc acetate dihydrate to ethyl orthosilicate is 0.4-0.6:0.7-1.3, and the molar ratio of zinc acetate dihydrate to diethanolamine is 0.8-1.2:1.

[0025] A method for preparing the thermal label comprises the following steps: taking a base paper layer and a thermal coating, coating the upper surface of the base paper layer with the thermal coating at room temperature, and curing the thermal coating under ultraviolet light for 0.5-3 seconds to form a thermal layer, thereby obtaining a thermal label.

[0026] In the above technical solution, the conditions for ultraviolet lamp irradiation are: UV energy is 80-100j.

[0027] The preparation method of the thermal label of the present invention has simple process, easy controllable operation, and is conducive to large-scale industrial production. The prepared thermal label has good oil resistance and light resistance after printing, and also has excellent friction resistance and heat friction resistance. It can be adapted to high-speed printing, has good printing clarity, and has excellent comprehensive performance.

[0028] The beneficial effects of the present invention are as follows: the thermal label of the present invention has a thermal layer and a base paper layer arranged in sequence from top to bottom, and the thermal layer is formed by coating a thermal coating. Thermal label strips are generally used for variable information printing applications. Compared with thermal label paper on the market, the thermal label of the present invention has stable quality, and the printed thermal label has good oil resistance and light resistance. It can be used or stored for a long time after printing, and also has better friction resistance and heat friction resistance, which is convenient for use as a cargo label. At the same time, it can be adapted to high-speed printing, and has better printing clarity and superior comprehensive performance.

[0029] At the same time, the preparation method of the thermal label is simple in process and easy to control, which is conducive to large-scale industrial production. The thermal label obtained has stable quality, good oil resistance and light resistance after printing, as well as excellent friction resistance and heat friction resistance. It can be adapted to high-speed printing and has good printing clarity. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0031] Example 1

[0032] In this embodiment, a thermosensitive label includes a thermosensitive layer and a base paper layer arranged in sequence from top to bottom, wherein the thermosensitive layer is formed by coating with a thermosensitive coating.

[0033] Furthermore, the thickness of the heat-sensitive layer is 1.5 μm, and the thickness of the base paper layer is 90 μm.

[0034] Furthermore, the thermosensitive coating comprises the following raw materials in parts by weight: 4 parts of colorless dye, 18 parts of developer, 8 parts of sensitizer, 20 parts of filler, 25 parts of adhesive, 5 parts of stabilizer and 4 parts of lubricant.

[0035] Furthermore, each part of the adhesive comprises the following raw materials in parts by weight: 30 parts of dipentaerythritol pentaacrylate, 8 parts of modified polytetrafluoroethylene, 5 parts of urea-formaldehyde resin, 4 parts of diallyl phthalate, 5 parts of talc, 2 parts of photoinitiator, 6 parts of deionized water and 1 part of emulsifier.

[0036] Furthermore, the preparation method of the adhesive comprises the following steps:

[0037] A1: Add emulsifier, modified polytetrafluoroethylene and deionized water into a reactor and mix and stir for 40 minutes to obtain a modified polytetrafluoroethylene dispersion;

[0038] A2: Dipentaerythritol pentaacrylate, urea-formaldehyde resin, diallyl phthalate, talc and photoinitiator were added to the modified polytetrafluoroethylene dispersion and stirred for 1.5 hours to obtain an adhesive.

[0039] Furthermore, the emulsifier is a mixture of CO-458 and OP-10 in a weight ratio of 2:1.

[0040] Furthermore, the preparation method of the thermosensitive coating comprises the following steps: mixing and stirring the colorless dye, the developer, the sensitizer, the filler, the adhesive, the stabilizer and the lubricant for 1.5 hours in a light-proof manner to obtain the thermosensitive coating.

[0041] Furthermore, the colorless dye is 3-diethylamino-7-chlorofluoran; the developer is bisphenol S; the sensitizer is a benzenesulfonic acid amide compound; the filler is calcium carbonate; the stabilizer is dibenzoyl terephthalate; and the lubricant is paraffin.

[0042] In this embodiment, the sensitizer is 1,2-bis(3-methylphenoxy)ethane.

[0043] Furthermore, the modified polytetrafluoroethylene comprises the following raw materials in parts by weight: 45 parts of polytetrafluoroethylene, 8 parts of zinc oxide-silicon dioxide sol and 2 parts of γ-methacryloxypropyltrimethoxysilane.

[0044] In this embodiment, the polytetrafluoroethylene is polytetrafluoroethylene with a particle size of 25 μm produced by Daikin Industries, Ltd.

[0045] Furthermore, the preparation method of the modified polytetrafluoroethylene comprises the following steps:

[0046] B1: Deionized water is added to polytetrafluoroethylene to prepare a polytetrafluoroethylene dispersion having a solid content of 70%;

[0047] B2: Add zinc oxide-silica sol, γ-methacryloxypropyltrimethoxysilane and polytetrafluoroethylene dispersion into the reactor and stir evenly, then maintain at 95°C and perform ultrasonic treatment for 2 hours. After natural cooling, wash the precipitate in the reactor with distilled water and anhydrous ethanol by suction filtration twice each, then put it into a forced air drying oven and dry it for 12 hours. Grind the dried powder for later use.

[0048] B3: Add the ground powder into a crucible, and then transfer it to a sintering furnace protected by nitrogen. The sintering temperature is 600°C and the sintering time is 40 minutes. After heating is completed and naturally cooled, modified polytetrafluoroethylene can be obtained.

[0049] In the above technical solution, in step B2, the frequency of ultrasonic treatment is 800 Hz.

[0050] Furthermore, the preparation method of the zinc oxide-silicon dioxide sol comprises the following steps: dissolving zinc acetate dihydrate in anhydrous ethanol at 50° C., then slowly adding diethanolamine and ethyl orthosilicate into the solution and stirring continuously for 1 hour to obtain the zinc oxide-silicon dioxide sol.

[0051] Furthermore, the molar ratio of zinc acetate dihydrate to ethyl orthosilicate is 0.5:0.9, and the molar ratio of zinc acetate dihydrate to diethanolamine is 1:1.

[0052] A method for preparing the thermal label comprises the following steps: taking a base paper layer and a thermal coating, coating the upper surface of the base paper layer with the thermal coating at room temperature, and curing the thermal coating under ultraviolet light for 1.5 seconds to form a thermal layer, thereby obtaining a thermal label.

[0053] Furthermore, the conditions of ultraviolet lamp irradiation are: UV energy is 80j.

[0054] Example 2

[0055] In this embodiment, the thermosensitive coating includes the following raw materials in parts by weight: 6 parts of colorless dye, 20 parts of developer, 10 parts of sensitizer, 25 parts of filler, 30 parts of adhesive, 6 parts of stabilizer and 5 parts of lubricant.

[0056] Furthermore, the adhesive comprises the following raw materials in parts by weight: 40 parts of dipentaerythritol pentaacrylate, 12 parts of modified polytetrafluoroethylene, 6 parts of urea-formaldehyde resin, 4 parts of diallyl phthalate, 6 parts of talc, 2 parts of photoinitiator, 10 parts of deionized water and 1.5 parts of emulsifier.

[0057] A method for preparing the thermal label comprises the following steps: taking a base paper layer and a thermal coating, coating the thermal coating on the upper surface of the base paper layer at room temperature, and curing it under ultraviolet light for 2 seconds to form a thermal layer to obtain a thermal label.

[0058] Furthermore, the conditions of ultraviolet lamp irradiation are: UV energy is 85j.

[0059] The rest of the content of this embodiment is the same as that of Embodiment 1.

[0060] Example 3

[0061] In this embodiment, the thermosensitive coating includes the following raw materials in parts by weight: 8 parts of colorless dye, 22 parts of developer, 12 parts of sensitizer, 30 parts of filler, 35 parts of adhesive, 8 parts of stabilizer and 6 parts of lubricant.

[0062] Furthermore, the adhesive comprises the following raw materials in parts by weight: 45 parts of dipentaerythritol pentaacrylate, 15 parts of modified polytetrafluoroethylene, 7 parts of urea-formaldehyde resin, 45 parts of diallyl phthalate, 7 parts of talc, 3 parts of photoinitiator, 12 parts of deionized water and 2 parts of emulsifier.

[0063] A method for preparing the thermal label comprises the following steps: taking a base paper layer and a thermal coating, coating the upper surface of the base paper layer with the thermal coating at room temperature, and curing the thermal coating under ultraviolet light for 2.5 seconds to form a thermal layer, thereby obtaining a thermal label.

[0064] Furthermore, the conditions of ultraviolet lamp irradiation are: UV energy is 90j.

[0065] The rest of the content of this embodiment is the same as that of Embodiment 1.

[0066] Performance testing

[0067] The thermal labels prepared in Example 2 and the turkey brand thermal paper on the market were printed by a thermal paper printer. When the temperature in the printer reached 50°C, the colorless dye and the developer began to react, and the thermal labels gradually developed color. The printed thermal labels were subjected to a performance test to test the oil resistance, light resistance, friction resistance, heat friction resistance and clarity after high-speed printing of the thermal labels prepared in Example 2 and the turkey brand thermal paper on the market.

[0068] (1) Oil resistance test: Place the thermal label in vegetable oil for 150 hours, take it out and clean it, and observe whether the image fades. The test data is shown in Table 1 below:

[0069] Table 1

[0070]

[0071] (2) Light resistance test: A 45-watt xenon lamp was used to irradiate the surface of the thermal label for 1 hour. The test data is shown in Table 2 below:

[0072] Table 2

[0073]

[0074] (3) Friction resistance test: At room temperature, use sandpaper to rub the surface of the thermal label back and forth 50 times. Heat friction resistance test: At 50°C, use a carton to rub the surface of the thermal label back and forth 80 times. The test data are shown in Table 3 below:

[0075] Table 3

[0076]

[0077] (4) Printing clarity test: Use a thermal printer to print at a high speed of 200 mm / s. The test data is shown in Table 4 below:

[0078] Table 4

[0079]

[0080] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A thermal label, characterized in that: It includes a heat-sensitive layer and a base paper layer arranged in sequence from top to bottom, wherein the heat-sensitive layer is formed by coating a heat-sensitive coating; The thermosensitive coating comprises the following raw materials in parts by weight: 4-8 parts of leuco dye, 18-22 parts of developer, 8-12 parts of sensitizer, 10-30 parts of filler, 25-35 parts of adhesive, 5-8 parts of stabilizer and 4-6 parts of lubricant; Each part of the adhesive comprises the following raw materials in parts by weight: 30-45 parts of dipentaerythritol pentaacrylate, 5-15 parts of modified polytetrafluoroethylene, 5-7 parts of urea-formaldehyde resin, 4-5 parts of diallyl phthalate, 5-7 parts of talc, 2-3 parts of photoinitiator, 3-12 parts of deionized water and 1-2 parts of emulsifier; The preparation method of the modified polytetrafluoroethylene comprises the following steps: B1: Add deionized water to polytetrafluoroethylene to prepare a polytetrafluoroethylene dispersion with a solid content of 65-75%; B2: Add zinc oxide-silica sol, γ-methacryloxypropyltrimethoxysilane and polytetrafluoroethylene dispersion into the reactor and stir evenly, then maintain at 80-110° C. and perform ultrasonic treatment for 1-3 hours. After cooling naturally, wash, dry and grind the precipitate in the reactor for later use; B3: Add the ground powder into a crucible, and then transfer it to a sintering furnace protected by nitrogen. The sintering temperature is 550-650°C and the sintering time is 30-45 minutes. After heating is completed and naturally cooled, modified polytetrafluoroethylene can be obtained.

2. A thermal label according to claim 1, characterized in that: The preparation method of the adhesive comprises the following steps: A1: Add emulsifier, modified polytetrafluoroethylene and deionized water into a reactor and mix and stir for 35-45 minutes to obtain a modified polytetrafluoroethylene dispersion; A2: Add dipentaerythritol pentaacrylate, urea-formaldehyde resin, diallyl phthalate, talc and photoinitiator into the modified polytetrafluoroethylene dispersion and stir for 1-3 hours to obtain an adhesive.

3. A thermal label according to claim 1, characterized in that: The emulsifier is prepared by mixing CO-458 and OP-10 at a weight ratio of 1.8-2.2:

1.

4. A thermal label according to claim 1, characterized in that: The preparation method of the thermosensitive coating comprises the following steps: mixing and stirring a colorless dye, a developer, a sensitizer, a filler, an adhesive, a stabilizer and a lubricant for 1-3 hours in a light-proof manner to obtain the thermosensitive coating.

5. A thermal label according to claim 1, characterized in that: The colorless dye is 3-diethylamino-7-chlorofluoran; the color developer is bisphenol S; the sensitizer is a benzenesulfonic acid amide compound; and the stabilizer is dibenzoyl terephthalate.

6. A thermal label according to claim 1, characterized in that: The modified polytetrafluoroethylene comprises the following raw materials in parts by weight: 45-55 parts of polytetrafluoroethylene, 8-11 parts of zinc oxide-silicon dioxide sol and 2-3 parts of gamma-methacryloxypropyltrimethoxysilane.

7. A method for preparing a thermosensitive label according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: taking a base paper layer and a thermosensitive coating, coating the upper surface of the base paper layer with the thermosensitive coating at room temperature, and curing the layer under ultraviolet light for 0.5-3 seconds to form a thermosensitive layer, thereby obtaining a thermosensitive label.

Images