Decoloring ink and preparation process thereof

Abstract

The decoloration ink is prepared from the following components in parts by weight: 30 to 40 parts of 60 DEG C temperature sensing decoloration dye, 10 to 12 parts of titanium dioxide, 6 to 8 parts of dispersing agent, 10 to 20 parts of inkjet resin, 10 to 15 parts of polyethylene glycol, 6 to 8 parts of triethanolamine, 10 to 15 parts of antifreezing agent, 2 to 4 parts of mildew preventive, 2 to 4 parts of surfactant and 100 to 120 parts of water. The invention also comprises a preparation process of the decolorizing ink. The decolorizing ink disclosed by the invention is high in color saturation and brightness, free from color reversion at a low temperature (-50 DEG C), stable in effect and environment-friendly in formula; a dispersion machine and a filter screen can be used for preparation at normal temperature, the operation process is simple, batch production can be realized, and the effect is stable; the paint can be widely applied to marking and scribing of home furnishing and clothes, can also be used for decoloration treatment of digital oil painting manuscripts, and solves the problem that the manuscript numbers are difficult to cover by light-color pigments.

Description

Technical Field

[0001] The present invention relates to the technical field of ink, and in particular to a decolorizing ink and a preparation process thereof. Background Art

[0002] With growing environmental awareness, the issue of disposable writing paper is gaining attention. Typically, paper written with a ballpoint pen or other marker leaves irreversible marks and ends up in the wastebasket after use or writing, resulting in a very low reusability rate. In offices, a large amount of printed or copied paper is generated daily, and most of it ends up in the wastebasket or shredder after reading. This creates a significant waste of resources, and the continued demand for paper puts a constant strain on the environment. This is where decolorizable ink comes in.

[0003] Thermal erasable inks are divided into gel pen ink and leather marking ink. Thermo-erasable gel pen ink uses friction-generated heat from the silicone tip of the pen barrel to erase cleanly, leaving no marks. Thermal erasable leather marking ink can be used for temporary marking on clothing, leather, and other products. The color can be removed with an iron, hair dryer, or oven.

[0004] The principle of conventional erasable ink (thermal vanishing ink) is that the color of the ink can be eliminated by any heating method, including frictional heating. The color returns when cooled to a certain temperature. This disappearance and color development process is mainly achieved by the microcapsule pigments in the ink. Thermal vanishing ink is colored at room temperature, but it disappears when heated to 50°C-60°C and reappears when cooled to -5°C-20°C. This is reversible. The specific temperature for the onset of color loss is around 45°C, and the temperature for complete color loss is around 55°C.

[0005] However, the existing color-erasable ink starts to develop at a temperature of about -5°C and fully develops at a temperature of about -20°C. In some cases (such as in some areas in the north with lower temperatures), this cannot meet the use requirements. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a decolorizing ink with a low low-temperature decolorization temperature and a preparation process thereof.

[0007] The technical solution adopted by the present invention to solve the technical problem is: The color-erasable ink of the present invention comprises the following components, by weight: 30-40 parts of a 60°C temperature-sensitive color-erasable dye, 10-12 parts of titanium dioxide, 6-8 parts of a dispersant, 10-20 parts of an inkjet resin, 10-15 parts of polyethylene glycol, 6-8 parts of triethanolamine, 10-15 parts of an antifreeze agent, 2-4 parts of a mildewcide, 2-4 parts of a surfactant, and 100-120 parts of water.

[0008] Preferably, the titanium dioxide is at least one of anatase titanium dioxide, rutile titanium dioxide, 706 titanium dioxide, and 966 titanium dioxide.

[0009] Preferably, the dispersant is any one of dispersant MF, dispersant CNF, dispersant NNO, dispersant 1101, dispersant 1008, and dispersant 190.

[0010] Preferably, the inkjet resin is at least one of amino silicone resin liquid CS-2000, polyamide-imide resin liquid RI-925, polysiloxane resin liquid PL-2075, 6183A resin liquid, water-based transparent PU resin, and 6000-3 inkjet resin.

[0011] Preferably, the antifreeze agent is at least one of ethylene glycol, propylene glycol, diethylene glycol, and glycerol.

[0012] Preferably, the surfactant is at least one of an imidazoline surfactant, a betaine surfactant BS-12, an ammonium oxide surfactant, a quaternary ammonium salt organosilicon gemini surfactant, and a 104E surfactant.

[0013] Preferably, the mildew preventer is a BIT mildew preventer.

[0014] The preparation process of the color-eliminating ink of the present invention comprises the following steps: (1) Weighing titanium dioxide, a dispersant, and water in parts by weight, mixing them, and dispersing them in a disperser to obtain a first mixture; Furthermore, in step (1), the speed of the disperser is set to 500-700 r / min and the time is 10-15 min. If the speed of the disperser is too low or the time is too short, the stirring and dispersion will be uneven.

[0015] (2) adding a 60°C thermochromic dye, an inkjet resin, polyethylene glycol, an antifreeze agent, triethanolamine, a mildew inhibitor, and a surfactant to the first mixture obtained in step (1) in parts by weight, and dispersing the mixture in a disperser to obtain a final mixture; Since titanium dioxide is a powder, adding and mixing it twice can make the mixing more uniform.

[0016] Furthermore, in step (2), the speed of the disperser is set to 600-800 r / min and the time is 10-20 min. If the speed of the disperser is too low or the time is too short, the stirring and dispersion will be uneven.

[0017] (3) The final mixture obtained in step (2) is defoamed and then filtered to obtain a decolorizing ink.

[0018] Furthermore, in step (3), the defoaming is performed by standing still. The filtration is performed by using an 800-mesh filter. The filtration can filter out most impurities.

[0019] Beneficial effects

[0020] The achromatic ink of the present invention can achieve a color-resistant effect at low temperatures (-50°C). It exhibits a sensitive decoloring effect, high color saturation and brightness, and no color reversion at low temperatures (-50°C). It also exhibits stable effects and an environmentally friendly formula. It can be prepared at room temperature using a disperser and filter screen, resulting in a simple operation process, mass production, and stable results. It can be widely used for marking lines on household items and clothing, and can also be used to decolorize digital painting drafts, resolving the problem of light-colored pigments making it difficult to cover draft numbers. It has innovative applications in the DIY field.

[0021] The reaction mechanism of the color-eliminating ink of the present invention: The principle of disappearance and color development of the color-eliminating ink of the present invention is mainly achieved through the repeated disappearance and color development of the microcapsule pigment in the ink. When the temperature exceeds 60°C, the pigment microcapsule structure is destroyed, resulting in color loss; at room temperature, the pigment microcapsule structure is intact, allowing color development. Hydrogen bonds exist between antifreeze molecules, especially glycerol molecules, and water molecules. This hydrogen bond weakens with decreasing temperature, thereby lowering the crystallization point and freezing point of water, providing a moisturizing effect. At the same time, polyethylene glycol can improve the emulsification, rheological properties, and anti-migration properties of the ink, thereby increasing the stability of the ink. With the synergistic effect of the two, the color can be maintained at a low temperature of -50°C without reversion. The addition of high-whiteness titanium dioxide to the formula makes the color development higher and more saturated. If the amount of polyethylene glycol added is too low, the color-eliminating ink may not be able to withstand low temperatures of -50°C.

[0022] The color-erasable ink of the present invention can be decolorized above 60° C. and does not return to color at a low temperature of -50° C. The color-erasing effect is sensitive and the color saturation and brightness are high.

[0023] The present invention incorporates titanium dioxide, polyethylene glycol, an antifreeze agent, particularly glycerin, and a thermochromic dye. These components are uniformly dispersed and mixed in a certain proportion under specific addition process conditions to produce a color-eliminating ink. This color-eliminating ink exhibits a sensitive decolorizing effect, high color saturation and brightness, and exhibits no color reversion at low temperatures. The ink exhibits stable results and an environmentally friendly formula. DETAILED DESCRIPTION

[0024] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art further understand the present invention, but are not intended to limit the present invention in any manner. It should be noted that those skilled in the art may make various modifications and improvements without departing from the scope of the present invention. These modifications and improvements all fall within the scope of protection of the present invention.

[0025] Example 1

[0026] The black decolorizing ink of this embodiment comprises the following components in parts by weight: 40 parts of 60°C thermochromic black dye (commercially available product of Shenzhen Oriental Color Change Technology Co., Ltd., the same as in the following examples), 10 parts of 706 titanium dioxide, 6 parts of dispersant 1008, 10 parts of 6000-3 inkjet resin (commercially available product of Guangzhou Yihua Digital Technology Co., Ltd., the same as in the following examples), 10 parts of polyethylene glycol, 6 parts of triethanolamine, 10 parts of glycerol, 2 parts of BIT mildew inhibitor, 2 parts of 104E surfactant, and 110 parts of water.

[0027] The preparation process of the black decolorizing ink of this embodiment includes the following steps: (1) Weigh 706 titanium dioxide, dispersant 1008 and water in parts by weight, mix them, and disperse them in a disperser at a speed of 550 r / min and a time of 10 min to obtain a first mixture; (2) Adding 60°C thermochromic black dye, 6000-3 inkjet resin, polyethylene glycol, glycerol, triethanolamine, BIT mildew inhibitor, and 104E surfactant to the first mixture obtained in step (1) in parts by weight, and dispersing in a disperser at a speed of 650 r / min for 20 min to obtain a final mixture; (3) The final mixture obtained in step (2) was allowed to stand for defoaming, and then filtered through an 800-mesh filter to obtain a black thermochromic ink.

[0028] Control Example 1 (without titanium dioxide)

[0029] A formula and preparation process of black decolorizing ink: A black decolorizable ink comprises the following components, by weight: 40 parts of a 60°C thermochromic black dye (available from Shenzhen Dongfang Bianse Technology Co., Ltd.), 6 parts of a dispersant 1008, 10 parts of a 6000-3 inkjet resin (available from Guangzhou Yihua Digital Technology Co., Ltd.), 2 parts of polyethylene glycol, 6 parts of triethanolamine, 10 parts of glycerin, 2 parts of a BIT mildewcide, 2 parts of a 104E surfactant, and 110 parts of water.

[0030] The preparation process is as follows: (1) Add 60°C thermochromic black dye, dispersant 1008, 6000-3 inkjet resin, polyethylene glycol, glycerol, triethanolamine, BIT mildew inhibitor, 104E surfactant, and water according to weight, disperse in a disperser at a speed of 650 r / min for 20 min to obtain a final mixture; (2) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a black thermochromic ink.

[0031] Control Example 2 (without polyethylene glycol and glycerol)

[0032] A black decolorizable ink comprises the following components in parts by weight: 40 parts of a 60°C thermosensitive decolorizable black dye, 10 parts of 706 titanium dioxide, 6 parts of a dispersant 1008, 10 parts of a 6000-3 inkjet resin, 6 parts of triethanolamine, 2 parts of a BIT mildewcide, 2 parts of a 104E surfactant, and 110 parts of water.

[0033] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008, and water according to the weight fraction ratio, mix them, and disperse them in a disperser at a speed of 550 r / min for 10 min to obtain a first mixture; (2) Adding 60°C thermochromic black dye, 6000-3 inkjet resin, triethanolamine, BIT mildew inhibitor, and 104E surfactant to the first mixture obtained in step (1) in parts by weight, and dispersing in a disperser at a speed of 650 r / min for 20 min to obtain a final mixture; (3) The final mixture obtained in step (2) was allowed to stand for defoaming, and then filtered through an 800-mesh filter to obtain a black thermochromic ink.

[0034] Example 2

[0035] The red erasable ink of this embodiment comprises the following components, by weight: 35 parts of a 60°C thermochromic red dye, 12 parts of 706 titanium dioxide, 8 parts of a dispersant 1008, 15 parts of a 6183A resin solution, 12 parts of polyethylene glycol, 6 parts of triethanolamine, 12 parts of glycerin, 2 parts of a BIT mildew inhibitor, 2 parts of a betaine surfactant BS-12, and 120 parts of water.

[0036] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008 and water in parts by weight, mix them, and disperse them in a disperser at a speed of 600 r / min for 15 minutes to obtain a first mixture; (2) Add 60°C thermochromic red dye, 6000-3 inkjet resin, polyethylene glycol, glycerol, triethanolamine, BIT mildew inhibitor, and betaine surfactant BS-12 to the first mixture in parts by weight, and disperse in a disperser at a speed of 700 r / min for 10 min to obtain a final mixture; (3) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a red thermochromic ink.

[0037] Control Example 3 (without polyethylene glycol)

[0038] A red decolorizable ink comprises the following components, by weight: 35 parts of a 60°C thermochromic red dye, 12 parts of 706 titanium dioxide, 8 parts of a dispersant 1008, 15 parts of a 6000-3 inkjet resin, 6 parts of triethanolamine, 12 parts of glycerol, 2 parts of a BIT mildewcide, 2 parts of a betaine surfactant BS-12, and 120 parts of water.

[0039] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008 and water in parts by weight, mix them, and disperse them in a disperser at a speed of 600 r / min for 15 minutes to obtain a first mixture; (2) Add 60°C thermochromic red dye, 6000-3 inkjet resin, glycerin, triethanolamine, BIT mildew inhibitor, and betaine surfactant BS-12 to the first mixture in parts by weight, and disperse in a disperser at a speed of 700 r / min for 10 min to obtain a final mixture; (3) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a red thermochromic ink.

[0040] Control Example 4 (without glycerin)

[0041] A red decolorizable ink comprises the following components, by weight: 35 parts of a 60°C thermochromic red dye, 12 parts of 706 titanium dioxide, 8 parts of a dispersant 1008, 15 parts of a 6000-3 inkjet resin, 6 parts of triethanolamine, 12 parts of polyethylene glycol, 2 parts of a BIT mildewcide, 2 parts of a betaine surfactant BS-12, and 120 parts of water.

[0042] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008 and water in parts by weight, mix them, and disperse them in a disperser at a speed of 600 r / min for 15 minutes to obtain a first mixture; (2) Add 60°C thermochromic red dye, 6000-3 inkjet resin, polyethylene glycol, triethanolamine, BIT mildew inhibitor, and betaine surfactant BS-12 to the first mixture in parts by weight, and disperse in a disperser at a speed of 700 r / min for 10 min to obtain a final mixture; (3) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a red thermochromic ink.

[0043] The synergistic effect of glycerin and polyethylene glycol: Hydrogen bonds form between glycerin antifreeze molecules and water molecules. These bonds weaken as the temperature decreases, thereby lowering the crystallization and freezing points of water, providing a moisturizing effect. Polyethylene glycol improves the rheological and emulsifying properties of the ink, enhancing its stability. The synergistic effect of these two ingredients allows the ink to maintain its molecular structure even at temperatures as low as -50°C.

[0044] Example 3

[0045] A yellow decolorizable ink comprises the following components, by weight: 40 parts of a 60°C thermochromic yellow dye, 10 parts of 706 titanium dioxide, 8 parts of a dispersant 1008, 15 parts of a 6000-3 inkjet resin, 10 parts of polyethylene glycol, 6 parts of triethanolamine, 12 parts of propylene glycol, 2 parts of a BIT mildewcide, 2 parts of a 104E surfactant, and 120 parts of water.

[0046] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008 and water according to weight, mix them, and disperse them in a disperser at a speed of 600 r / min for 12 min to obtain a first mixture; (2) Add 60°C thermochromic yellow dye, 6000-3 inkjet resin, polyethylene glycol, glycerol, triethanolamine, BIT mildew inhibitor, and 104E surfactant to the first mixture in parts by weight, and disperse in a disperser at a speed of 700 r / min for 15 minutes to obtain a final mixture; (3) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a yellow thermochromic ink.

[0047] Example 4

[0048] A blue decolorizable ink comprises the following components, by weight: 38 parts of a 60°C thermosensitive decolorizable blue dye, 12 parts of 706 titanium dioxide, 8 parts of a dispersant 1008, 13 parts of a 6000-3 inkjet resin, 12 parts of polyethylene glycol, 6 parts of triethanolamine, 12 parts of glycerol, 2 parts of a BIT mildewcide, 2 parts of a 104E surfactant, and 115 parts of water.

[0049] The preparation process is as follows: (1) Weigh 706 titanium dioxide, dispersant 1008, and water in parts by weight, mix them, and disperse them in a disperser at a speed of 650 r / min for 13 min to obtain a first mixture; (2) Add 60°C thermochromic blue dye, 6000-3 inkjet resin, polyethylene glycol, glycerol, triethanolamine, BIT mildew inhibitor, and 104E surfactant to the first mixture in parts by weight, and disperse in a disperser at a speed of 650 r / min for 12 minutes to obtain a final mixture; (3) The final mixture was allowed to stand for defoaming and then filtered through an 800-mesh filter to obtain a blue thermochromic ink.

[0050] Performance testing The performance of the thermochromic inks obtained in Examples 1-4 and Comparative Examples 1-4 was tested. The results are shown in Table 1.

[0051] Testing method for each parameter: Use ink to draw a 2cmx2cm square frame on a cotton drawing board. After decolorizing with a hot air blower, place it at -5℃, -20℃, and -50℃ for 30 minutes respectively to see if the color returns. Refer to the national standard: Thermal color-changing anti-counterfeiting ink GB / T187752-2002.

[0052] Table 1

Claims

1. A decolorizing ink, characterized in that: The composition comprises the following components by weight: 30-40 parts of 60°C temperature-sensitive color-decolorizing dye, 10-12 parts of titanium dioxide, 6-8 parts of dispersant, 10-20 parts of inkjet resin, 10-15 parts of polyethylene glycol, 6-8 parts of triethanolamine, 10-15 parts of antifreeze agent, 2-4 parts of mildewproof agent, 2-4 parts of surfactant and 100-120 parts of water.

2. The decolorizing ink according to claim 1, characterized in that: The titanium dioxide is at least one of anatase titanium dioxide, rutile titanium dioxide, 706 titanium dioxide, and 966 titanium dioxide.

3. The decolorizing ink according to claim 1 or 2, characterized in that: The dispersant is any one of dispersant MF, dispersant CNF, dispersant NNO, dispersant 1101 , dispersant 1008 , and dispersant 190 .

4. The decolorizing ink according to claim 1 or 2, characterized in that: The inkjet resin is at least one of amino silicone resin liquid CS-2000, polyamide-imide resin liquid RI-925, polysiloxane resin liquid PL-2075, 6183A resin liquid, water-based transparent PU resin, and 6000-3 inkjet resin.

5. The decolorizing ink according to claim 1 or 2, characterized in that: The antifreeze agent is at least one of ethylene glycol, propylene glycol, diethylene glycol and glycerol.

6. The decolorizing ink according to claim 1 or 2, characterized in that: The surfactant is at least one of an imidazoline surfactant, a betaine surfactant BS-12, an ammonium oxide surfactant, a quaternary ammonium salt organic silicon gemini surfactant, and a 104E surfactant; and / or the mildew inhibitor is a BIT mildew inhibitor.

7. A process for preparing the decolorizing ink as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Weighing titanium dioxide, a dispersant and water in parts by weight, mixing them, and dispersing them in a disperser to obtain a first mixture; (2) adding 60° C. thermochromic dye, inkjet resin, polyethylene glycol, antifreeze, triethanolamine, mildewproof agent, and surfactant to the first mixture obtained in step (1) in parts by weight, and dispersing the mixture in a disperser to obtain a final mixture; (3) The final mixture obtained in step (2) is defoamed and then filtered to obtain a decolorizing ink.

8. The process for preparing decolorizing ink according to claim 7, characterized in that: In step (1), the dispersion machine is set to have a dispersion speed of 500-700 r / min and a dispersion time of 10-15 min.

9. The process for preparing decolorizing ink according to claim 7 or 8, characterized in that: In step (2), the dispersion machine is set to have a dispersion speed of 600-800 r / min and a dispersion time of 10-20 min.

10. The process for preparing decolorizing ink according to claim 7 or 8, characterized in that: In step (3), defoaming is performed by standing still; and / or filtering is performed by using an 800-mesh filter.

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