Thermal transfer ribbon for protection of carbon and method of making same

Abstract

The application discloses a thermal transfer printing protective carbon tape and a preparation method thereof. The thermal transfer printing protective carbon tape comprises a substrate layer, a back coating layer and a protective layer. The back coating layer is attached to one side of the substrate layer. The protective layer is attached to the side of the substrate layer away from the back coating layer. The protective layer comprises, by weight fraction, 25-50 parts of an acrylic modified silicone resin, 5-30 parts of an ethylene-butene block copolymer resin, 5-15 parts of a wax powder and 5-15 parts of a filler. The thermal transfer printing protective carbon tape has better weather resistance and friction resistance, and can improve the weather resistance and durability of thermal transfer printing outdoor advertisements and signs.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of heat transfer printing, and particularly relates to a heat transfer printing protective carbon tape and a preparation method thereof. BACKGROUND

[0002] At present, heat transfer printing or inkjet printing is a relatively reliable and economical method for printing outdoor advertisements and signs, but the outdoor advertisements and signs prepared by using such methods need to be used outdoors for many years, and therefore high requirements are put forward for their weather resistance and durability. To this end, a common method is to add a transparent protective film to the outer layer of the ink, and the protective film needs to have ultraviolet protection function in addition to preventing external damage and pollution, so as to avoid the chemical reaction and degradation of the pigments and ink binder resins in the ink caused by ultraviolet light, and affect the color saturation and presentation effect of the outdoor advertisements and signs. SUMMARY

[0003] In order to solve the above technical problems, the purpose of the present application is to provide a heat transfer printing protective carbon tape with better weather resistance and friction resistance.

[0004] In order to achieve the above purpose, the technical scheme of the present application is as follows: a heat transfer printing protective carbon tape, comprising:

[0005] a substrate layer;

[0006] a back coating layer attached to one side of the substrate layer; and

[0007] a protective layer attached to the side of the substrate layer away from the back coating layer;

[0008] wherein the protective layer comprises, by weight fraction, 25-50 parts of acrylic modified silicone resin, 5-30 parts of ethylene-butylene block copolymer resin, 5-15 parts of wax powder, and 5-15 parts of filler.

[0009] In the above technical scheme, the average molecular weight of the acrylic modified silicone resin is 10000-100000, and the TG value is 85℃-180℃.

[0010] In the above technical scheme, the average molecular weight of the acrylic modified silicone resin is 20000-50000, and the TG value is 100℃-120℃.

[0011] In the above technical scheme, the average molecular weight of the ethylene-butylene block copolymer resin is 10000-30000.

[0012] In the above technical scheme, the filler is one or more of talc powder, calcium carbonate, mica powder, barium sulfate, magnesium sulfate, and titanium white powder.

[0013] The substrate layer is a plate or a film, and the material is polypropylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol or polymethyl methacrylate.

[0014] The thickness of the substrate layer is 2-15 microns, the thickness of the back coating layer is 0.2-1.0 microns, and the thickness of the protective layer is 0.5-2.5 microns.

[0015] The raw material of the back coating layer is one or more of polyurethane modified silicone resin, acrylic modified silicone resin, polyvinyl acetal resin, polyvinyl butyral resin.

[0016] The second object of the present application is to provide a preparation method of the above-mentioned heat transfer printing protective carbon tape with better weather resistance and friction resistance.

[0017] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows: a preparation method of the above-mentioned heat transfer printing protective carbon tape, comprising the following steps:

[0018] Step 1, preparation of liquid:

[0019] Back coating liquid: dissolve the raw material of the back coating layer in an organic solvent and mix uniformly to obtain the back coating liquid, which is ready for use;

[0020] Protective liquid: first dissolve the resin material in the protective layer raw material in an organic solvent and mix uniformly, then add wax powder and filler, and mix again to obtain the protective liquid, which is ready for use;

[0021] Step 2, surface treatment:

[0022] Take the substrate layer, and perform corona treatment on both sides of the substrate layer;

[0023] Step 3, coating and drying:

[0024] The back coating liquid obtained in step 1 is coated on one side of the substrate layer treated in step 2, and then dried to obtain the back coating layer;

[0025] The protective liquid obtained in step 1 is coated on the other side of the substrate layer treated in step 2, and then dried to obtain the protective layer;

[0026] The coating sequence of the back coating liquid and the protective liquid on the substrate layer in step 3 can be changed.

[0027] The back coating liquid and the protection liquid in step 3 are coated by using a ceramic anilox roller with 200-250 lines, and the coating speed is 60-100 m / min; the drying temperature of the back coating liquid is 50-100 DEG C, and the drying time is 40-60 s; the drying temperature of the protection liquid is 40-100 DEG C, and the drying time is 40-60 s.

[0028] Compared with the prior art, the heat transfer printing protective carbon tape provided by the application is suitable for outdoor advertising and packaging industries, and can improve the weather resistance and durability of heat transfer printing outdoor advertising and signs, because the heat transfer printing protective carbon tape has good weather resistance and friction resistance. The resins in the protective layer of the carbon tape are mainly two kinds of resins: one is ethylene-butene block copolymer resin, and the other is acrylic modified silicone resin. The heat transfer printing protective layer carbon tape prepared by adjusting the proportion of the two resins has high light resistance. The Si-O-Si bond in the acrylic modified silicone resin has high bond energy, which can effectively reduce the free radical reaction caused by UV light. In order to improve the flexibility of the pattern and solve the problem of brittle protective layer at low temperature, ethylene-butene block copolymer (SEBS) is added. SEBS has good ultraviolet stability, oxidation resistance and thermal stability, and can also improve the brittleness of the coating, improve the flexibility and substrate surface adhesion effect. A small amount of filler is added to the protective layer carbon tape, which can migrate to the surface of the protective layer during the heat transfer printing process, reduce the friction coefficient of the coating surface, and make the coating have strong friction resistance. The mica powder in the filler can refract light to a certain extent on the surface of the protective layer during outdoor use, further reducing the light intensity received by the protected pattern. When the heat transfer printing protective carbon tape provided by the application is used for printing, the printed product has better weather resistance and friction resistance compared with the printed product without the protective layer. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The layer structure diagram of the heat transfer printing protective carbon tape is shown in the figure.

[0030] Figure 2 The sample plate for printing test in the embodiment of the application is shown in the figure.

[0031] In the figure: 1, back coating layer; 2, substrate layer; 3, protective layer. DETAILED DESCRIPTION

[0032] The embodiment of the application provides a heat transfer printing protective carbon tape, which comprises:

[0033] a substrate layer;

[0034] a back coating layer attached to one side of the substrate layer; and

[0035] a protective layer attached to the side of the substrate layer away from the back coating layer;

[0036] The thickness of the substrate layer is 2-15 μm, the thickness of the back coating layer is 0.2-1.0 μm, and the thickness of the protective layer is 0.5-2.5 μm (the thicknesses of the substrate layer, the back coating layer and the protective layer within the ranges can ensure the thickness of the thermal transfer carbon ribbon, improve the adhesion of the substrate layer, and make the heat transfer efficiency of the print head high to ensure that the coating can achieve precise peeling effect).

[0037] The protective layer comprises, by weight fraction, 25-50 parts of acrylic modified silicone resin, 5-30 parts of ethylene-butylene block copolymer resin, 5-15 parts of wax powder, and 5-15 parts of filler. The average molecular weight of the acrylic modified silicone resin is 10000-100000, and the TG value (glass transition temperature) is 85℃-180℃. Preferably, the average molecular weight of the acrylic modified silicone resin is 20000-50000, and the TG value is 100℃-120℃. The average molecular weight of the ethylene-butylene block copolymer resin is 10000-30000. The filler is one or more of talc, calcium carbonate, mica powder, barium sulfate, magnesium sulfate and titanium dioxide.

[0038] The substrate layer is a plate or a film, and the specific material can be polypropylene, polyethylene terephthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol or polymethyl methacrylate.

[0039] The raw material of the back coating layer is one or more of polyurethane modified silicone resin, acrylic modified silicone resin, polyvinyl acetal resin, and polyvinyl butyral resin.

[0040] The thermal transfer protective carbon tape provided by the embodiment improves the light stability of the coating layer through the acrylic modified silicone resin in the protective layer, improves the brittleness of the coating layer through the flexibility and UV resistance of the SEBS resin, and adds fillers to the protective layer, which mainly help the protective layer to separate from the substrate layer. In addition, due to the migration of the fillers to the surface of the coating layer after transfer, a concave-convex micro-nano structure is formed, which improves the abrasion resistance of the coating layer. At the same time, the concave-convex surface causes the light to be diffusely reflected on the protective layer, further reducing the absorption of light by the underlying layer, thereby improving the light resistance of the transferred pattern. The acrylic modified silicone resin can improve the image protection effect and clarity of the thermal transfer sheet on the transferred body. From the perspective of image transfer integrity and clarity, the selection and amount of the acrylic modified silicone resin are crucial, especially the molecular weight and TG value have a greater impact. The average molecular weight of the selected acrylic modified silicone resin in the application is 10000-100000, preferably 20000-50000. Too low or too high molecular weight may cause uneven distribution of the protective layer on the surface of the substrate layer during coating. Selecting this molecular weight range can reduce the brittleness problem of the coating layer caused by too high molecular weight of the thermoplastic acrylic acid while considering the protection effect. Preferably, the TG value of the acrylic modified silicone resin is 85℃-180℃, preferably 100℃-120℃. A higher TG value can ensure the thermal stability of the coating layer after transfer. In order to further improve the abrasion resistance of the transferred pattern and reduce the brittleness of the coating layer, the molecular weight of the SEBS resin material is preferably 10000-30000. It can improve the flexibility of the thermal transfer carbon tape without affecting the light transmittance of the protective layer, and improve the scratch resistance of the transferred pattern.

[0041] The embodiment of the application also provides a preparation method of the thermal transfer protective carbon tape with better weather resistance and abrasion resistance.

[0042] In order to achieve the above purpose, the technical scheme of the application is as follows: a preparation method of the thermal transfer protective carbon tape as described above, comprising the following steps:

[0043] Step 1, liquid preparation (wherein the preparation of the back coating liquid and the protective liquid is not sequential) :

[0044] Back coating liquid: dissolve the raw materials of the back coating layer in an organic solvent and mix uniformly to obtain the back coating liquid, which is ready for use (wherein the amount of the organic solvent is appropriate) ;

[0045] Protective liquid: first dissolve the resin material in the protective layer raw material in an organic solvent and mix uniformly, then add wax powder and fillers, and mix again to obtain the protective liquid, which is ready for use (wherein the amount of the organic solvent is appropriate) ;

[0046] Step 2, surface treatment:

[0047] Take the substrate layer and perform corona treatment on both sides of the substrate layer (the method of corona treatment is prior art and is not described here);

[0048] Step 3, coating:

[0049] The back coating solution obtained in step 1 is coated on one side of the substrate layer treated in step 2, and then dried to obtain a back coating layer (after drying, almost all the organic solvents in the back coating layer are volatilized);

[0050] The protective solution obtained in step 1 is coated on the other side of the substrate layer treated in step 2, and then dried to obtain a protective layer (after drying, almost all the organic solvents in the protective layer are volatilized). In step 3, the order of coating the back coating solution and the protective solution can be adjusted to coat the protective solution first and then coat the back coating solution (specifically, the one with a higher drying temperature can be coated first).

[0051] In the above technical solution, both the back coating solution and the protective solution in step 3 are coated using a 200-250 line ceramic screen roller, and the coating speed is 60-100 m / min; the drying temperature of the back coating solution is 50-100℃, and the drying time is 40-60s; the drying temperature of the protective solution is 40-100℃, and the drying time is 40-60s.

[0052] Example 1

[0053] This embodiment provides a thermal transfer protective carbon tape, which comprises a back coating layer, a substrate layer and a protective layer (a yellow color pigment, a magenta color pigment and a cyan color pigment are added to the protective layer to form a colored transfer pattern, wherein the yellow color pigment is a yellow pigment of Pigment Yellow 14, the magenta color pigment is a magenta pigment of Pigment Red 48:2, and the cyan color pigment is a blue pigment of Pigment Blue 15:4), which are sequentially attached from top to bottom.

[0054] The substrate layer is a polyethylene terephthalate film with a thickness of 4.5μm, and both sides thereof are subjected to corona treatment.

[0055] The preparation raw materials of the back coating solution are: 2-butanone 30 parts, toluene 30 parts, polyurethane modified silicone resin 10 parts, acrylic modified silicone resin 10 parts, polyvinyl acetal-based resin 30 parts, and polyvinyl butyral-based resin 30 parts, by weight. 2-butanone and toluene are used as organic solvents, and the coating thickness of the back coating layer is 0.2-1.0μm.

[0056] The raw materials for preparing the protective liquid are: by weight: 40 parts of 2-butanone, 40 parts of toluene, 30 parts of acrylic modified silicone resin, 30 parts of SEBS resin, 10 parts of mica powder and 10 parts of wax powder, wherein 2-butanone and toluene are used as organic solvents, and the coating thickness of the protective layer is 0.6 μm.

[0057] Both the back coating and the protective layer are applied using a 230-line ceramic anilox roller. The back coating is dried at 100°C for 60 seconds, while the protective layer is dried at 60°C for 60 seconds before use.

[0058] A back coating is first applied to the substrate layer, and after the back coating is dried, a protective layer is applied, and then the protective layer is dried.

[0059] Example 2

[0060] Same as Example 1, except that the raw materials for preparing the protective liquid are, by weight: 40 parts of 2-butanone, 40 parts of toluene, 30 parts of acrylic modified silicone resin, 20 parts of SEBS resin, 10 parts of mica powder and 10 parts of wax powder, and the coating thickness of the protective layer is 0.8 μm.

[0061] Example 3

[0062] Similar to Example 1, except that the raw materials for preparing the protective liquid are, by weight, 40 parts of 2-butanone, 40 parts of toluene, 20 parts of acrylic-modified silicone resin, 20 parts of SEBS resin, 10 parts of mica powder and 10 parts of wax powder, and the coating thickness of the protective layer is 1.0 μm.

[0063] Example 4

[0064] Similar to Example 1, except that the raw materials for preparing the protective liquid are, by weight, 40 parts of 2-butanone, 40 parts of toluene, 30 parts of acrylic-modified silicone resin, 10 parts of SEBS resin, 10 parts of mica powder and 10 parts of wax powder, and the coating thickness of the protective layer is 1.2 μm.

[0065] Example 5

[0066] Similar to Example 1, except that the raw materials for preparing the protective liquid are, by weight, 40 parts of 2-butanone, 40 parts of toluene, 30 parts of acrylic-modified silicone resin, 15 parts of SEBS resin, 20 parts of mica powder and 20 parts of wax powder, and the coating thickness of the protective layer is 1.5 μm.

[0067] Comparative Example 1

[0068] Similar to Example 1, except that the resin in the protective layer is acrylic resin (i.e., acrylic resin replaces acrylic-modified silicone resin and SEBS resin).

[0069] Comparative Example 2

[0070] Same as Example 1, except that the resin in the protective layer is vinyl chloride vinyl acetate resin (i.e., vinyl chloride vinyl acetate resin replaces acrylic modified silicone resin and SEBS resin).

[0071] Comparative Example 3

[0072] Same as Example 1, except that no filler and wax powder are added to the protective layer.

[0073] Results Analysis

[0074] Performance testing of printed samples from Examples 1-5 and Comparative Examples 1-3.

[0075] Printing Test: Using a color label printer (Matan Sprinter3), the resin ribbon prepared in this embodiment was used to transfer the following onto PVC tape: Figure 2 The image shown; the printing speed is set to 0.5m / min, and the printing density of yellow, magenta and cyan is 23 (these are print parameters available for the printer, and the specific density values ​​correspond to the printer's default parameters). Then, a protective ribbon is attached, with a printing density of 23 (same as above, not repeated here).

[0076] The weather resistance of the printed samples was evaluated using the following methods:

[0077] Referring to the xenon lamp aging conditions in the national standard GB / T 18833-2012 Road Traffic Reflective Film, the film was aged for 1800 hours in a xenon lamp aging test chamber. The surface was observed for wrinkles, blistering, cracking, and other phenomena. The color difference value before and after accelerated aging was measured.

[0078] After visually confirming the formed image, the image was then scraped 100 times using a 1000g weight wrapped in a clean cloth. The following evaluation criteria were then used for evaluation:

[0079] A: No obvious defects were observed in the image after scratching;

[0080] B: A slight missing component was observed in the image;

[0081] NG: Numerous missing parts were observed in the image.

[0082] The test results of Examples 1-5 are shown in Table 1:

[0083] Table 1 shows the test results of the thermal transfer ribbons corresponding to Examples 1-5.

[0084]

[0085] The test results of Comparative Examples 1-3 are shown in Table 2:

[0086] Table 2 shows the test results of the thermal transfer ribbons corresponding to Comparative Examples 1-3.

[0087]

[0088] Combining Tables 1 and 2, it can be seen that the use of a mixture of acrylic-modified silicone resin and SEBS resin can effectively improve the abrasion resistance of the coating. The addition of fillers significantly improves the abrasion resistance of the coating and also plays an important role in lightfastness. Comparing Comparative Example 1 and Comparative Example 2, as well as Examples 1-5, the protective layer mainly uses acrylic resin, which exhibits significant brittleness; after xenon lamp testing, the brittleness increases significantly. From Example 5 and Comparative Example 3, it can be seen that removing the particulate material from the coating and increasing the content of acrylic-modified silicone resin reduces the abrasion resistance of the protective layer's carbon ribbon. Comparing Examples 1 and 4, it can be seen that increasing the coating thickness can better improve weather resistance. A comparison of Examples 1, Comparative Example 2, and Comparative Example 3 shows that the resin using 30 parts of acrylic-modified silicone resin and SEBS resin in the embodiments of this invention has better weather resistance than vinyl chloride series resins.

[0089] Because outdoor advertising needs to be exposed to various environments for extended periods, printed outdoor advertising products require excellent weather resistance. The heat transfer protective ribbon provided in this embodiment can be applied to the outdoor advertising printing industry. The resin in this heat transfer protective ribbon is mainly an inorganic-organic composite resin (organosilicon-acrylic composite resin). When this resin is used with a curing agent, the resulting curing system has excellent weather resistance and excellent adhesion to the substrate layer. It also has high transparency and minimal impact on the retroreflection coefficient. It combines the properties of both organosilicon and acrylic. When printing with this heat transfer protective ribbon, the printed products have superior weather resistance compared to acrylic or organosilicon-based printed products currently used in the transportation industry, combining the advantages of both.

Claims

1. A heat transfer protective ribbon, characterized in that, include: Substrate layer; A back coating is attached to one side of the substrate layer; and A protective layer is attached to the side of the substrate layer opposite to the back coating layer; The protective layer comprises, by weight, 25-50 parts of acrylic-modified silicone resin, 5-30 parts of ethylene-butene block copolymer resin, 5-15 parts of wax powder, and 5-15 parts of mica powder; The acrylic-modified silicone resin has an average molecular weight of 10,000-100,000 and a TG value of 85℃-180℃. The average molecular weight of the ethylene-butene block copolymer resin is 10,000-30,000.

2. The heat transfer protective ribbon according to claim 1, characterized in that, The average molecular weight of the acrylic-modified silicone resin is 20,000-50,000, and the TG value is 100℃-120℃.

3. The heat transfer protective ribbon according to claim 1, characterized in that, The substrate layer is a sheet or film material, and its material is polypropylene, polyethylene naphthalate, polyethylene terephthalate, polyethylene, polyvinyl alcohol or polymethyl methacrylate.

4. The heat transfer protective ribbon according to claim 1, characterized in that, The thickness of the substrate layer is 2-15 μm, the thickness of the back coating layer is 0.2-1.0 μm, and the thickness of the protective layer is 0.5-2.5 μm.

5. The heat transfer protective ribbon according to claim 1, characterized in that, The raw material for the back coating is one or more of the following: polyurethane modified silicone resin, acrylic modified silicone resin, polyvinyl alcohol acetal resin, and polyvinyl alcohol butyral resin.

6. A method for preparing a thermal transfer protective ribbon as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1, Prepare the solution: Back coating liquid: Dissolve the raw materials of the back coating in an organic solvent and mix well to obtain the back coating liquid for later use; Protective solution: First, dissolve the resin material in the protective layer raw material in an organic solvent and mix well. Then, add wax powder and filler, and mix well again to obtain the protective solution for later use. Step 2, Surface treatment: Take the substrate layer and perform corona treatment on both sides of the substrate layer; Step 3, coating and drying: The back coating liquid obtained in step 1 is applied to one side of the substrate layer treated in step 2, and then dried to obtain the back coating layer; The protective liquid obtained in step 1 is applied to the other side of the substrate layer treated in step 2, and then dried to obtain a protective layer; In step 3, the order in which the back coating liquid and the protective liquid are applied on the substrate layer can be changed.

7. The method for preparing thermal transfer protective ribbon according to claim 6, characterized in that, In step 3, both the back coating liquid and the protective liquid are applied using a 200-250 line ceramic anilox roller at a coating speed of 60-100 m / min. The drying temperature of the back coating liquid is 50-100℃, and the drying time is 40-60 s. The drying temperature of the protective liquid is 40-100℃, and the drying time is 40-60 s.

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