Thermal transfer ribbon for outdoor traffic true color pattern printing and preparation method thereof

Abstract

The invention relates to a thermal transfer ribbon for outdoor traffic true color pattern printing and a preparation method thereof, and relates to the technical field of thermal transfer. The thermal transfer ribbon comprises a back coating layer, a base material and a color layer which are sequentially arranged from top to bottom. The back coating is prepared from the following raw materials in parts by weight: 8 to 12 parts of cellulose acetate propionate, 0.1 to 0.8 part of high-cohesiveness resin, 0.5 to 1.0 part of a lubricating agent, 0.4 to 0.7 part of filler and 2 to 3 parts of an auxiliary agent; the color layer is prepared from the following raw materials in parts by weight: 8 to 9 parts of methacrylic acid copolymer, 2 to 3 parts of vinyl chloride-vinyl acetate resin, 7 to 9 parts of pigment and 0.5 to 1 part of wax. The thermal transfer ribbon prepared by the invention is used for thermal transfer, can realize thermal transfer multi-color overlapped true color printing, has excellent light resistance and weather resistance, and is simple in structure and good in economical efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of thermal transfer, and in particular to a thermal transfer carbon ribbon for outdoor traffic true color pattern printing and a preparation method thereof. Background Art

[0002] Outdoor traffic signs are generally monochrome, but there are still true color patterns such as tourist signs. Thermal transfer printing is an important solution for preparing outdoor traffic signs, but traditional thermal transfer resin ribbons cannot meet the needs of true color pattern printing. Traditional thermal transfer ribbons are often designed with a dense wax system release layer. When printing true color patterns, yellow, red and blue three-color overlay printing is required. The dense wax system release layer, due to its extremely low surface tension, will seriously affect the transfer integrity and adhesion of the printing when printing the second and third colors, and often cannot obtain reliable true color icon patterns; the current mainstream imaging method for traffic true color sign patterns is to use inkjet printing, but because the light resistance and weather resistance of the pattern after inkjet printing cannot meet the requirements, the true color traffic sign patterns often fade within 1-2 years and cannot meet long-term reliable use. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a thermal transfer carbon ribbon for outdoor traffic true color pattern printing and a preparation method thereof. The thermal transfer carbon ribbon prepared by the present invention can realize thermal transfer multi-color stacking true color printing, and has excellent light resistance and weather resistance, and has a simple structure and good economy.

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

[0005] The first object of the present invention is to provide a thermal transfer ribbon for printing outdoor traffic true color patterns, characterized in that the thermal transfer ribbon comprises a back coating layer, a substrate, and a color layer arranged in sequence from top to bottom;

[0006] The color layer comprises the following raw materials in parts by weight: 8-9 parts of methacrylic acid copolymer, 2-3 parts of chloroacetic acid resin, 7-9 parts of pigment, and 0.5-1 part of wax.

[0007] The invention has the following beneficial effects: the thermal transfer carbon ribbon of the invention has a simple structure, does not have any auxiliary coatings such as adhesive layers and release layers, and has good economic efficiency. The thermal transfer carbon ribbon of the invention can realize thermal transfer multi-color stacking true color printing, can meet the needs of true color pattern printing, and has excellent light resistance and weather resistance. It can meet the requirements of long-term reliable use.

[0008] Based on the above technical solution, the present invention can also be improved as follows.

[0009] Further, the back coating layer comprises the following raw materials in parts by weight: 8-12 parts of cellulose acetate propionate, 0.1-0.8 parts of high-adhesive resin, 0.5-1.0 parts of lubricant, 0.4-0.7 parts of filler, 0.2-0.4 parts of antistatic agent, and 1-3 parts of cross-linking agent;

[0010] The high-bonding resin includes at least one of a polyester resin and a polyurethane resin;

[0011] The lubricant comprises at least one of phosphate ester, zinc stearate, glyceryl dioleate, and glyceryl monooleate;

[0012] The filler includes at least one of talc, kaolin, calcium carbonate, aluminum hydroxide, silicon dioxide, graphite, and boron nitride;

[0013] The antistatic agent includes at least one of glycerides and polyoxyethylene ethers;

[0014] The cross-linking agent is an isocyanate cross-linking agent.

[0015] The beneficial effect of adopting the above further solution is that the purpose of providing the back coating in the present invention is to prevent adverse effects such as stickiness or wrinkles caused by heating by the temperature-sensitive heating head during thermal transfer.

[0016] Preferably, the cellulose acetate propionate may also be replaced by polyvinyl acetal resin or polyvinyl butyral resin in the same weight proportion.

[0017] Preferably, the back coating layer also includes a dispersant and a leveling agent.

[0018] Furthermore, the pigment is an organic pigment; the color of the pigment includes at least one of red, yellow and blue.

[0019] The wax includes at least one of microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, low molecular weight polyethylene wax, candelilla wax, polyester wax, modified wax, fatty acid ester, and fatty acid amide.

[0020] The beneficial effects of adopting the above further scheme are: in the color layer, the methacrylic acid copolymer has good light transmittance, good light resistance and weather resistance, and good peeling transferability, which can ensure that the carbon ribbon has good transfer ability; the excellent pigment dispersibility and film-forming property of the chlorovinyl resin provide good help for the coating and film formation of the carbon ribbon, and at the same time, its good adhesion to the substrate PET ensures the good foil retention of the carbon ribbon ink. The chlorovinyl resin also contains high polar groups, which helps the good transfer adaptability of the carbon ribbon on various substrates; the wax can provide good smoothness of the pattern after printing and improve the friction resistance of the pattern. When the content is low, it cannot provide sufficient smoothness, and the friction resistance of the pattern decreases. When the content is too high, it affects the overlapping color printing during true color printing; directly adding wax powder to the color layer instead of selecting a wax system release layer can ensure that the main component of the pattern surface after printing is resin, and the pattern layer can be used as a good printing coating for subsequent color printing, ensuring that the true color pattern formed after multi-color printing has good adhesion and transfer integrity.

[0021] Preferably, the molecular weight of the low molecular weight polyethylene wax is 700-5000.

[0022] Furthermore, the molecular weight Mn of the methacrylic acid copolymer is greater than 80,000.

[0023] Furthermore, the methacrylic acid copolymer has a molecular weight Mn>11000 and a Tg>90°C.

[0024] Furthermore, the Tg of the methacrylic acid copolymer is above 100° C., and the content of the methacrylic acid copolymer in the color layer is 30%-50%.

[0025] The high molecular weight of the methacrylic acid copolymer is selected to give the printed pattern good light resistance and weather resistance. At the same time, the methacrylic acid copolymer has good waterproofness, which further improves the weather resistance of the printed pattern when used outdoors.

[0026] Furthermore, the vinyl chloride content in the chlorovinyl resin is greater than 85%, the degree of polymerization K is greater than 50, and the content is between 8% and 15%.

[0027] Furthermore, the wax is polyethylene wax; the weight content of the wax in the color layer is 0.5%-5%.

[0028] Furthermore, the organic pigment includes at least one of Pigment Yellow 150, Pigment Red 254, and Phthalocyanine Blue 15:4.

[0029] The beneficial effect of adopting the above further scheme is: the selection of this type of pigment has good light transmittance, light resistance and weather resistance, which can improve the good coloring effect and reliability of outdoor use during true color printing. When actually printing color pictures, the red, yellow and blue color layers can be superimposed for printing, so the color layer of the present invention can be adjusted according to actual conditions.

[0030] Furthermore, the particle size of the pigment is 0.1-0.2 um.

[0031] Furthermore, the substrate includes at least one of polyethylene terephthalate film, 1,4-polycyclohexylene dimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polyethylene film, polyvinyl chloride film, nylon film, and polyimide film.

[0032] Furthermore, the thickness of the substrate is 4-10 μm; the thickness of the back coating layer is 0.1-0.5 μm; and the thickness of the color layer is 0.6-1.2 μm.

[0033] Furthermore, the thickness of the substrate is 4-6 μm; the thickness of the back coating layer is 0.2-0.4 μm; and the thickness of the color layer is 0.8-1.0 μm.

[0034] A second object of the present invention is to provide a method for preparing a thermal transfer ribbon for outdoor traffic true color pattern printing, characterized in that the preparation method comprises the following steps:

[0035] S1, liquid preparation: back coating liquid: dissolve cellulose acetate and high-adhesive resin in a solvent, then add lubricant, filler, antistatic agent, stir and mix, finally add cross-linking agent to prepare back coating liquid, and set aside; color layer coating liquid: dissolve methacrylic acid copolymer, chloroacetic resin, pigment, wax in a solvent, then grind and prepare color layer coating liquid, and set aside;

[0036] S2, applying corona to both sides of the substrate;

[0037] S3, coating: coating the back coating liquid on one side of the substrate, and then drying to form a back coating for standby use; then coating the color layer coating liquid on the side of the substrate away from the back coating, and then drying to form a color layer, thus obtaining a thermal transfer carbon ribbon.

[0038] Furthermore, the temperature of the drying process to form the back coating layer is 60-100°C; the speed at which the back coating layer coating liquid is coated on the substrate is 60-100m / min; the temperature of the drying process to form the color layer is 60-100°C; the speed at which the color layer coating liquid is coated on the substrate is 60-100m / min. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural diagram of the thermal transfer carbon ribbon of the present invention;

[0040] Figure 2 This is a printed diagram of a test example of the present invention.

[0041] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0042] 1-substrate, 2-color layer, 3-back coating. DETAILED DESCRIPTION

[0043] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0044] Example 1: Preparation of thermal transfer ribbon for outdoor traffic true color pattern printing

[0045] S1. Prepare the solution: Back coating solution: Dissolve 10 parts of cellulose acetate propionate (Eastman CAP-482-0.5) and 0.5 parts of polyester resin (Toyobo polyester GK885) in 60 parts of 2-butanone and 25 parts of toluene, then add 0.3 parts of zinc stearate, 0.25 parts of phosphate, 0.2 parts of glycerol dioleate, 0.3 parts of talc, 0.2 parts of silicon dioxide, and 0.3 parts of antistatic agent (ATMER163; Croda, UK) and stir for 2 hours. Finally, add 2 parts of isocyanate and stir for 0.5 hours to prepare the back coating solution for use. Color layer coating solution: Dissolve 8 parts of methacrylic acid copolymer (Rohm M810 molecular weight 120000, Tg=10 4 ), 3 parts of chloroacetyl resin (Wacker H11 / 59) with 89% vinyl chloride content and 60 degree of polymerization, 8 parts of Pigment Red 254 (Senico 254), 1 part of wax (Honeywell 3405G) are dissolved in 40 parts of 2-butanone and 40 parts of toluene, and then ground to prepare a red color layer coating liquid for use. The yellow color layer coating liquid and the blue color layer coating liquid are the same as the red color layer coating liquid except that the pigments are Pigment Yellow 150 (DIC) and Pigment Blue 15:4 (DIC) respectively;

[0046] S2, applying corona to both sides of the substrate 1;

[0047] S3, coating: use a 250-line ceramic anilox roller and a gravure coater to coat the back coating liquid on one side of the substrate at a coating speed of 80 m / min, and then dry at 80°C to form a back coating layer 3 for standby use; then, at the same coating speed of 80 m / min, coat the red, yellow and blue color layer coating liquids on the side of the substrate 1 away from the back coating layer 3, respectively, and then dry at 80°C to form three different colors of color layers 2, thus obtaining red, yellow and blue thermal transfer carbon ribbons.

[0048] Embodiment 2-3:

[0049] In preparing the thermal transfer ribbon for outdoor traffic true color pattern printing, the difference between Example 2-3 and Example 1 is only the change in the number of color layer raw materials, and the remaining preparation steps, preparation conditions, and material sources are consistent with Example 1, as shown in Table 1:

[0050] Table 1

[0051]

[0052] Comparative Examples 1-3:

[0053] When preparing thermal transfer ribbons for outdoor traffic true color pattern printing, the difference between Example 1-3 and Example 1 is only the change in the number of color layer raw materials, and the remaining preparation steps and preparation conditions are consistent with Example 1, as shown in Table 2:

[0054] Table 2

[0055]

[0056] Test example: performance test

[0057] The thermal transfer carbon ribbon structure prepared in the embodiment and the comparative example is as follows Figure 1 As shown, the transfer integrity, pattern adhesion after printing, and accelerated aging of the pattern after printing of the thermal transfer carbon ribbons prepared in Examples 1-3 and Comparative Examples 1-3 were tested respectively, and the test methods are as follows:

[0058] (1) Transfer integrity test

[0059] The red, yellow and blue thermal transfer ribbons prepared in Examples 1-3 and Comparative Examples 1-3 were printed on 3M white reflective film using a thermal transfer traffic sign printer (manufactured by Hunan Dingyi Intelligent Manufacturing Co., Ltd., model DTP-1300). Figure 2 After printing, the color patterns shown were visually checked and evaluated. The evaluation criteria were as follows:

[0060] A: No untransferred pattern area is observed in the image;

[0061] B: <0.1% of the untransferred pattern was observed in the image;

[0062] C: <1% of the untransferred pattern was observed in the image;

[0063] NG: >1% of the non-transferred pattern was observed in the image.

[0064] (2) Adhesion test of transfer pattern

[0065] The red, yellow and blue thermal transfer ribbons prepared in Examples 1-3 and Comparative Examples 1-3 were printed on 3M white reflective film using a thermal transfer traffic sign printer (manufactured by Hunan Dingyi Intelligent Manufacturing Co., Ltd., model DTP-1300). Figure 2 After the color pattern shown, a peeling test was performed using a disk glass tester (BLJ-02; Jinan Languang Electromechanical Technology Co., Ltd.) and evaluated according to the following evaluation criteria:

[0066] OK: After peeling, the exposed white area is less than 1%;

[0067] NG: After peeling, the exposed white area is greater than 1%.

[0068] (3) Accelerated aging test

[0069] The red, yellow and blue thermal transfer ribbons prepared in Examples 1-3 and Comparative Examples 1-3 were printed on 3M white reflective film using a thermal transfer traffic sign printer (manufactured by Hunan Dingyi Intelligent Manufacturing Co., Ltd., model DTP-1300). Figure 2 The color pattern shown in the figure is then tested according to the operating method of GB / T 16422.2-2014 Plastics Laboratory Light Source Exposure Test Method Part 2: Xenon Arc Lamp. The test cycle is 1800h. After the test, the image formed is visually confirmed and evaluated. The evaluation criteria are as follows:

[0070] OK: The pattern has no obvious fading;

[0071] NG: The pattern is obviously faded.

[0072] The above tests were repeated three times, and the test results are shown in Table 3:

[0073] Table 3

[0074]

[0075] From Table 1, we can get:

[0076] (1) The transfer integrity, pattern adhesion after printing, and accelerated aging test results of the thermal transfer carbon ribbons of Examples 1-3 all passed, and the transfer integrity was A, which was better than the comprehensive performance of the carbon ribbon combination thermal transfer carbon ribbons of Comparative Examples 1-3 during the thermal transfer process.

[0077] (2) Compared with the embodiment, in the test results of comparative examples 1 and 2, more than 1% of the untransferred patterns were observed in the transferred image, and the transfer integrity was NG. It can be seen that the raw materials and the amount of raw materials added of the present invention provide help for the good transfer adaptability of the carbon ribbon on the substrate, which can greatly improve the transfer integrity.

[0078] (3) In the test results of comparative example 3 compared with the embodiment, in the accelerated aging test, the transferred image faded significantly and the result was NG. It can be seen that the thermal transfer carbon ribbon prepared by the present invention has excellent weather resistance and light resistance and can meet the requirements of long-term reliable use.

[0079] To sum up, the thermal transfer carbon ribbon provided by the present invention has a simple structure, and only includes a back coating, a substrate, and a color layer, without various auxiliary coatings such as adhesive layers and release layers, and is highly economical; it can realize thermal transfer multi-color overlay true color printing, and at the same time has excellent light resistance, weather resistance, and waterproof performance, further improving the reliable use of the printed pattern outdoors for a long time.

[0080] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A thermal transfer ribbon for outdoor traffic true color pattern printing, characterized in that: The thermal transfer ribbon comprises a back coating layer, a substrate, and a color layer arranged in sequence from top to bottom; The color layer comprises the following raw materials in parts by weight: 8-9 parts of methacrylic acid copolymer, 2-3 parts of chloroacetic acid resin, 7-9 parts of pigment, and 0.5-1 part of wax.

2. A thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 1, characterized in that: The back coating layer comprises the following raw materials in parts by weight: 8-12 parts of cellulose acetate propionate, 0.1-0.8 parts of high-adhesive resin, 0.5-1.0 parts of lubricant, 0.4-0.7 parts of filler, 0.2-0.4 parts of antistatic agent, and 1-3 parts of crosslinking agent; The high-bonding resin includes at least one of a polyester resin and a polyurethane resin; The lubricant comprises at least one of phosphate ester, zinc stearate, glyceryl dioleate, and glyceryl monooleate; The filler includes at least one of talc, kaolin, calcium carbonate, aluminum hydroxide, silicon dioxide, graphite, and boron nitride; The antistatic agent includes at least one of glycerides and polyoxyethylene ethers; The cross-linking agent is an isocyanate cross-linking agent.

3. The thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 1, characterized in that: The pigment is an organic pigment; the color of the pigment includes at least one of red, yellow and blue; The wax includes at least one of microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, low molecular weight polyethylene wax, candelilla wax, polyester wax, modified wax, fatty acid ester, and fatty acid amide.

4. A thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 3, characterized in that: The organic pigment includes at least one of Pigment Yellow 150, Pigment Red 254, and Phthalocyanine Blue 15:

4.

5. A thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 4, characterized in that: The particle size of the pigment is 0.1-0.2 um.

6. The thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 1, characterized in that: The substrate includes at least one of polyethylene terephthalate film, 1,4-polycyclohexylene dimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polyethylene film, polyvinyl chloride film, nylon film, and polyimide film.

7. The thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 1, characterized in that: The thickness of the substrate is 4-10 μm; the thickness of the back coating is 0.1-0.5 μm; and the thickness of the color layer is 0.6-1.2 μm.

8. The thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 7, characterized in that: The thickness of the substrate is 4-6 μm; the thickness of the back coating is 0.2-0.4 μm; and the thickness of the color layer is 0.8-1.0 μm.

9. A method for preparing a thermal transfer ribbon for outdoor traffic true color pattern printing according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1, liquid preparation: back coating liquid: dissolve cellulose acetate and high-adhesive resin in a solvent, then add lubricant, filler, antistatic agent, stir and mix, finally add cross-linking agent to prepare back coating liquid, and set aside; color layer coating liquid: dissolve methacrylic acid copolymer, chloroacetic resin, pigment, wax in a solvent, then grind and prepare color layer coating liquid, and set aside; S2, applying corona to both sides of the substrate; S3, coating: coating the back coating liquid on one side of the substrate, and then drying to form a back coating for standby use; then coating the color layer coating liquid on the side of the substrate away from the back coating, and then drying to form a color layer, thus obtaining a thermal transfer carbon ribbon.

10. The method for preparing a thermal transfer ribbon for outdoor traffic true color pattern printing according to claim 9, characterized in that: The temperature for drying to form the back coating layer is 60-100°C; the speed at which the back coating layer coating liquid is coated on the substrate is 60-100m / min; the temperature for drying to form the color layer is 60-100°C; the speed at which the color layer coating liquid is coated on the substrate is 60-100m / min.

Images