Weather-resistant double-color erasable thermo-sensitive paper and preparation method thereof

Abstract

The invention relates to weather-resistant double-color erasable thermo-sensitive paper and a preparation method thereof, and relates to the technical field of printing supplies. The two-color erasable thermo-sensitive paper comprises a protective layer and a thermo-sensitive coating, the thermo-sensitive coating comprises a red thermo-sensitive coating, a yellow thermo-sensitive coating and a blue thermo-sensitive coating which are sequentially arranged from top to bottom, and the protective layer is arranged on the red thermo-sensitive coating; according to the double-color erasable thermal sensitive paper, bright red is achieved through color overlapping of yellow and red, the three layers simultaneously develop color and overlap red and black, and meanwhile the yellow plays a role of an interlayer; yellow is matched with red for developing, so that the color density of red is improved, blue is matched with red, and yellow is beneficial for improving the color density and purity of black; and the high weather resistance of water resistance, gas resistance and ultraviolet resistance is realized through the synergistic effect of all the components in all the layers.

Description

Technical Field

[0001] The present invention relates to the technical field of printing consumables, and particularly relates to a weather-resistant two-color erasable thermal paper and a preparation method thereof. Background Art

[0002] Thermal paper was first developed by 3M Company in the United States in the 1950s. Subsequently, with the continuous development of thermal technology, coating technology, and printing equipment, as well as market and industry changes, thermal paper has now been widely used in various scenarios of people's clothing, food, housing, transportation, and work. Especially in the variable information fields such as mall cashiers, entertainment tickets, supermarket labels, express labels, medical electrocardiogram papers, movie tickets, boarding passes, warehousing, logistics, and transportation, the market scale is huge. Ordinary thermal paper generally consists of three layers. The lowest layer is the paper base layer, the second layer is the thermal coating layer, and the third layer is the film protection layer. Generally, the thermal coating layer contains two substances. One is a colorless dye, also known as a latent dye, which is a colorless or nearly colorless solid and will develop color when encountering an acid or an electron acceptor compound. The other is a developer. Under the condition of heating, the colorless dye and the developer will have a color development reaction to achieve information recording. However, current thermal paper is difficult to be used outdoors due to poor weather resistance. In view of this, the present invention provides a weather-resistant two-color erasable thermal paper and a preparation method thereof. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a weather-resistant two-color erasable thermal paper and a preparation method thereof. The purpose is to provide a weather-resistant two-color erasable thermal paper and a preparation method thereof for use in outdoor environments.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] In a first aspect, a weather-resistant two-color erasable thermal paper, the two-color erasable thermal paper includes a protection layer and a thermal coating layer. The thermal coating layer includes a red thermal coating layer, a yellow thermal coating layer, and a blue thermal coating layer arranged in sequence from top to bottom. A protection layer is provided on the red thermal coating layer;

[0006] The protection layer includes the following components in parts by weight: 10 - 40 parts of a heat conduction aid, 1 - 10 parts of an anti-ultraviolet aid, 1 - 5 parts of a lubricant, 30 - 75 parts of a first adhesive, and 30 - 50 parts of a first curing agent;

[0007] The red thermal coating layer includes the following components in parts by weight: 10 - 24 parts of a developer, 2 - 6 parts of a red thermal dye, 30 - 50 parts of a second adhesive, 3 - 8 parts of a filler, and 20 - 30 parts of a second curing agent;

[0008] The yellow thermosensitive coating comprises the following components by weight: 10-36 parts of a developer, 2-9 parts of a yellow thermosensitive dye, 50-80 parts of a third adhesive, 4-6 parts of a filler, and 20-30 parts of a third curing agent;

[0009] The blue thermosensitive coating comprises the following components by weight: 10-15 parts of a developer, 2-5 parts of a blue thermosensitive dye, 50-80 parts of a fourth adhesive, 4-6 parts of a filler, and 20-30 parts of a fourth curing agent.

[0010] The beneficial effects of the present invention are as follows: The two-color erasable thermosensitive paper realizes bright red through the superposition of yellow and red, and the three layers are simultaneously colored to stack out red and black two colors. At the same time, yellow plays a role of a separator layer; the combination of yellow and red for coloring is beneficial to improving the color density of red, and the combination of blue with red and yellow is beneficial to improving the color density and purity of black; and through the synergistic effect of the components in each layer, high weather resistance such as waterproof, airproof, and ultraviolet resistance is achieved.

[0011] On the basis of the above technical solution, the present invention can be further improved as follows.

[0012] Further, the heat conduction aid includes at least one of zinc oxide (ZnO), magnesium oxide (MgO), and aluminum oxide (Al 2 O 3 ); Preferably, the heat conduction aid includes zinc oxide (ZnO) and magnesium oxide (MgO), and the mass ratio of ZnO to MgO is 4:1; the heat conduction aid can reduce the cost while ensuring the heat conduction effect.

[0013] The ultraviolet resistance aid includes at least one of salicylate esters, benzophenone, benzotriazole, substituted acrylonitriles, and triazines;

[0014] The lubricant includes at least one of talcum powder, zinc stearate, mineral lubricants (such as machine oil), silicone oil, fatty acid amides, oleic acid, polyesters, and carboxylic acids;

[0015] The first adhesive includes at least one of polyvinyl alcohol (PVA), epoxy resins (one of acrylic epoxy resins, glycidylamine epoxy resins, glycidyl ester epoxy resins, glycidyl ether epoxy resins, and epoxy olefin epoxy resins), hydroxy acrylate, and amino resins;

[0016] The first curing agent includes at least one of epoxy acrylate, organosilicon acrylate, and acrylic resin.

[0017] Further, the developer in the red thermosensitive coating includes where P = 12-37, the molecular weight of the developer exceeds 500, and the molecule itself is not easily movable, which can reduce the possibility of its fading;

[0018] The red thermosensitive dye includes at least one of the following formulas 1-1 to 1-7:

[0019]

[0020]

[0021] The second adhesive includes at least one of epoxy resin, hydroxyacrylate, and amino resin;

[0022] The filler in the red thermosensitive coating includes at least one of magnesium oxide, zinc oxide, and titanium dioxide;

[0023] The second curing agent includes at least one of polyamide and triisocyanurate.

[0024] Furthermore, the developer in the yellow thermosensitive coating includes where P = 12 to 37;

[0025]

[0026] The yellow thermosensitive dye includes at least one of the following formulas 2-1 to 2-2:

[0027] The third adhesive includes at least one of epoxy resin, hydroxyacrylate, and amino resin;

[0028] The filler in the yellow thermosensitive coating includes at least one of magnesium oxide, zinc oxide, and titanium dioxide;

[0029] The third curing agent includes at least one of polyamide and triisocyanurate.

[0030] Furthermore, the developer in the blue thermosensitive coating includes where P = 12 to 37; the blue thermosensitive dye includes at least one of the following formulas 3-1 to 3-6:

[0031]

[0033] The fourth adhesive includes at least one of epoxy resin, hydroxyacrylate, and amino resin;

[0034] The filler in the blue thermosensitive coating includes at least one of magnesium oxide, zinc oxide, and titanium dioxide;

[0035] The fourth curing agent includes at least one of polyamide and triisocyanurate.

[0036] Furthermore, the thickness of the red thermosensitive coating is 5um to 8um, and the thickness of the yellow thermosensitive coating is 3 to 14um.

[0037] Further, the thickness of the blue thermosensitive coating is 5 um to 8 um, and the thickness of the protective layer is 1 um to 3 um.

[0038] Further, the two-color erasable thermosensitive paper further includes a thermosensitive paper substrate; the thermosensitive paper substrate includes any one of art paper, white cardboard, kraft paper, double-sided offset paper, glassine paper, and stone paper.

[0039] Further, the thickness of the thermosensitive paper substrate is 100 um to 140 um.

[0040] In a second aspect, a method for preparing a weather-resistant two-color erasable thermosensitive paper includes the following steps:

[0041] (1) Prepare the coating liquid of the protective layer from the components of the protective layer; prepare the coating liquid of the red thermosensitive coating from the components of the red thermosensitive coating; prepare the coating liquid of the yellow thermosensitive coating from the components of the yellow thermosensitive coating; prepare the coating liquid of the blue thermosensitive coating from the components of the blue thermosensitive coating.

[0042] (2) Coat the coating liquid of the blue thermosensitive coating, the coating of the yellow thermosensitive coating, and the coating liquid of the red thermosensitive coating on the thermosensitive paper substrate in sequence, and dry to obtain a thermosensitive coating; coat the coating liquid of the protective layer on the thermosensitive coating, and dry to obtain a protective layer.

[0043] (3) Compose the thermosensitive paper substrate, the thermosensitive coating, and the protective layer through a hot pressing process to obtain a weather-resistant two-color erasable thermosensitive paper. Description of the drawings

[0044] Figure 1 Schematic diagram of the two-color erasable thermosensitive paper of the present invention Figure Ⅰ ;

[0045] Figure 2 Schematic diagram of the two-color erasable thermosensitive paper of the present invention Figure Ⅱ . Detailed implementation manners

[0046] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. For those not specifying specific techniques or conditions in the examples, the techniques or conditions described in the literature in this field are followed, or the product specifications are followed. For reagents or instruments not indicating the manufacturer, they are all conventional products that can be purchased through regular channels.

[0047] Description of the sources of materials and reagents:

[0048] The color developers in the following examples and comparative examples ( In the formula, P = 12 - 37), the synthetic route is as follows: Octadecyl isocyanate and p-aminophenol are added to a beaker containing toluene, and the reaction is carried out in a water bath at 60 °C until it cannot be stirred anymore. Then, it is filtered by suction, recrystallized, and dried to obtain the color developer.

[0049] Example 1:

[0050] This example relates to a weather-resistant double-color erasable thermal paper. The double-color erasable thermal paper includes a protective layer and a thermal-sensitive coating. The thermal-sensitive coating includes a red thermal-sensitive coating, a yellow thermal-sensitive coating, and a blue thermal-sensitive coating arranged in sequence from top to bottom. A protective layer is provided on the red thermal-sensitive coating ( Figure 1 and 2 );

[0051] The protective layer includes the following specific components by weight: 40 parts of zinc oxide, 5 parts of ultraviolet-resistant auxiliary benzotriazole, 3 parts of solid lubricant talcum powder, and 75 parts of epoxy resin adhesive; 50 parts of curing agent epoxy acrylate, and the thickness is controlled at 3 μm;

[0052] The red thermal-sensitive coating includes the following specific components by weight: 24 parts of color developer, 6 parts of thermal dye (peach red), 30 parts of epoxy resin adhesive, 30 parts of polyamide curing agent, and 6 parts of magnesium oxide filler, and the thickness is controlled at 6 μm; The color developer is In the formula, P = 12 - 37;

[0053] The yellow thermal-sensitive coating includes the following specific components by weight: 36 parts of color developer, 9 parts of thermal dye (Formula 2-1), 30 parts of epoxy resin adhesive, 30 parts of polyamide curing agent, and 6 parts of magnesium oxide filler, and the thickness is controlled at 6 μm; The color developer is In the formula, P = 12 - 37;

[0054] The blue thermal-sensitive coating includes the following specific components by weight: 15 parts of color developer, 5 parts of thermal dye (Formula 3-1), 80 parts of epoxy resin adhesive, and 4 parts of filler; The color developer is In the formula, P = 12 - 37;

[0055] This example relates to a preparation method of a weather-resistant double-color erasable thermal paper, including the following steps:

[0056] (1) Prepare the coating liquids of the protective layer from the components of the protective layer; prepare the coating liquids of the red thermal-sensitive coating from the components of the red thermal-sensitive coating; prepare the coating liquids of the yellow thermal-sensitive coating from the components of the yellow thermal-sensitive coating; prepare the coating liquids of the blue thermal-sensitive coating from the components of the blue thermal-sensitive coating;

[0057] (2) Coat the coating solution of the blue thermosensitive coating, the yellow thermosensitive coating, and the coating solution of the red thermosensitive coating on the thermosensitive paper substrate in sequence, and dry it to obtain a thermosensitive coating; coat the coating solution of the protective layer on the thermosensitive coating, and dry it to obtain a protective layer;

[0058] (3) Compose the thermosensitive paper substrate, the thermosensitive coating, and the protective layer through a hot pressing process to obtain a weather-resistant two-color erasable thermosensitive paper.

[0059] Example 2:

[0060] In this example, the thickness of the yellow color-developing layer is controlled at 3 um, and the others are the same as in Example 1.

[0061] Example 3:

[0062] In this example, the adhesive resin in the protective layer is replaced with hydroxyacrylate; the curing agent in the protective layer, the red thermosensitive coating, the yellow thermosensitive coating, and the blue thermosensitive coating is replaced with isocyanuric acid trimer, and the others are the same as in Example 1.

[0063] Example 4:

[0064] In this example, the adhesives in the red thermosensitive coating, the yellow thermosensitive coating, and the blue thermosensitive coating are replaced with amino resins, and the others are the same as in Example 1.

[0065] Example 5:

[0066] In this example, the heat conduction assistant in the protective layer is replaced with 20 parts, and the others are the same as in Example 1.

[0067] Control Example 1:

[0068] On the basis of Example 1, the yellow coating is removed, and the blue is replaced with a black dye, and the rest are the same.

[0069] Control Example 2:

[0070] On the basis of Example 1, the magenta dye is replaced with one of orange red, pink, and scarlet.

[0071] Test Example:

[0072] (1) Erasure

[0073] Erasure method: Print on a zebra printer, with a red printing density of 20 and a black printing density of 30.

[0074] Erasure efficiency: (Color density after erasure - Base color density) / (Printing color density - Base color density) * 100%.

[0075] The color densities before and after erasure of the weather-resistant two-color erasable thermosensitive paper of Example 1 are shown in Tables 1 and 2 below.

[0076] Table 1 Color Density and Its Erasure Efficiency

[0077]

[0078] Table 2 Color Coordinates

[0079]

[0080] Wherein, in Table 2, L is the luminance, A is the red-green chromaticity, and B is the yellow-blue chromaticity.

[0081] In summary, the present invention realizes the cooperation of the protective layer and the thermosensitive coating, two-color display, and erasable red-black superimposed color. Moreover, through the synergistic effect of each component in each layer, high weather resistance such as waterproof, gas-proof, and ultraviolet-resistant is achieved.

[0082] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A weather-resistant two-color erasable thermal paper, characterized in that: The two-color erasable thermal paper comprises a protective layer and a thermal coating, wherein the thermal coating comprises a red thermal coating, a yellow thermal coating and a blue thermal coating arranged in sequence from top to bottom, and a protective layer is arranged on the red thermal coating; The protective layer comprises the following components by weight: 10 to 40 parts of a thermal conductive agent, 1 to 10 parts of an anti-ultraviolet agent, 1 to 5 parts of a lubricant, 30 to 75 parts of a first adhesive, and 30 to 50 parts of a first curing agent; The red thermosensitive coating comprises the following components by weight: 10 to 24 parts of a developer, 2 to 6 parts of a red thermosensitive dye, 30 to 50 parts of a second adhesive, 3 to 8 parts of a filler, and 20 to 30 parts of a second curing agent; The yellow thermosensitive coating comprises the following components by weight: 10 to 36 parts of a developer, 2 to 9 parts of a yellow thermosensitive dye, 50 to 80 parts of a third adhesive, 4 to 6 parts of a filler and 20 to 30 parts of a third curing agent; The blue thermosensitive coating comprises the following components by weight: 10-15 parts of a developer, 2-5 parts of a blue thermosensitive dye, 50-80 parts of a fourth adhesive, 4-6 parts of a filler and 20-30 parts of a fourth curing agent.

2. The weather-resistant two-color erasable thermal paper according to claim 1, characterized in that: The thermal conductive aid comprises at least one of zinc oxide, magnesium oxide and aluminum oxide; The anti-ultraviolet additive includes at least one of salicylates, benzophenone, benzotriazole, substituted acrylonitrile and triazine; The lubricant includes at least one of talc, zinc stearate, mineral lubricant, silicone oil, fatty acid amide, oleic acid, polyester, and carboxylic acid; The first adhesive comprises at least one of polyvinyl alcohol, epoxy resin, hydroxy acrylate, and amino resin; The first curing agent includes at least one of epoxy acrylate, silicone acrylate, and acrylic resin.

3. The weather-resistant two-color erasable thermal paper according to claim 2, characterized in that: The developer in the red heat-sensitive coating includes Wherein P = 12 to 37; The red thermosensitive dye comprises at least one of the following formulas 1-1 to 1-7: The second adhesive comprises at least one of epoxy resin, hydroxy acrylate, and amino resin; The filler in the red heat-sensitive coating includes at least one of magnesium oxide, zinc oxide and titanium dioxide; The second curing agent includes at least one of polyamide and isocyanurate.

4. The weather-resistant two-color erasable thermal paper according to claim 2, characterized in that: The developer in the yellow heat-sensitive coating includes Wherein P=12-37; the yellow thermosensitive dye comprises at least one of the following formulas 2-1 to 2-2: The third adhesive includes at least one of epoxy resin, hydroxy acrylate, and amino resin; The filler in the yellow thermosensitive coating includes at least one of magnesium oxide, zinc oxide and titanium dioxide; The third curing agent includes at least one of polyamide and isocyanate.

5. The weather-resistant two-color erasable thermal paper according to claim 2, characterized in that: The developer in the blue thermosensitive coating includes Wherein P=12-37; the blue thermosensitive dye comprises at least one of the following formulas 3-1 to 3-6: The fourth adhesive comprises at least one of epoxy resin, hydroxy acrylate, and amino resin; The filler in the blue thermosensitive coating includes at least one of magnesium oxide, zinc oxide and titanium dioxide; The fourth curing agent includes at least one of polyamide and isocyanurate.

6. A weather-resistant two-color erasable thermal paper according to any one of claims 1 to 5, characterized in that: The thickness of the red thermosensitive coating is 5um to 8um, and the thickness of the yellow thermosensitive coating is 3um to 14um.

7. A weather-resistant two-color erasable thermal paper according to any one of claims 1 to 5, characterized in that: The thickness of the blue thermosensitive coating is 5um to 8um, and the thickness of the protective layer is 1um to 3um.

8. The weather-resistant two-color erasable thermal paper according to any one of claims 1 to 5, characterized in that: The two-color erasable thermal paper also includes a thermal paper substrate; the thermal paper substrate includes any one of coated paper, white cardboard, kraft paper, offset paper, glassine paper and stone paper.

9. The weather-resistant two-color erasable thermal paper according to claim 2, characterized in that: The thickness of the thermal paper substrate is 100um to 140um.

10. A method for preparing a weather-resistant two-color erasable thermal paper according to any one of claims 1 to 9, characterized in that: The steps include: (1) preparing the components of the protective layer into a coating liquid of the protective layer; preparing the components of the red thermosensitive coating into a coating liquid of the red thermosensitive coating; preparing the components of the yellow thermosensitive coating into a coating liquid of the yellow thermosensitive coating; preparing the components of the blue thermosensitive coating into a coating liquid of the blue thermosensitive coating; (2) applying the coating liquid of the blue thermosensitive coating, the coating liquid of the yellow thermosensitive coating, and the coating liquid of the red thermosensitive coating on a thermosensitive paper substrate in sequence, and drying to obtain a thermosensitive coating; applying the coating liquid of the protective layer on the thermosensitive coating, and drying to obtain a protective layer; (3) The thermal paper substrate, the thermal coating layer and the protective layer are compounded by a hot pressing process to obtain a weather-resistant two-color erasable thermal paper.

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