Thermal sublimation foaming thermal transfer ribbon and preparation method thereof

Abstract

The invention discloses a thermal sublimation foaming thermal transfer ribbon and a preparation method thereof.The thermal sublimation foaming thermal transfer ribbon comprises a dye layer and a functional thermal transfer ribbon layer which are sequentially arranged in the front-back direction, a bottom coating is laid at the upper end of the dye layer, and the upper end of the bottom coating is flush with the upper end of the functional thermal transfer ribbon layer; a base film layer is laid at the upper ends of the bottom coating layer and the functional thermal transfer ribbon layer, a back coating layer is laid at the upper end of the base film layer, and the functional thermal transfer ribbon layer comprises a release layer, a foaming layer and a white bonding layer which are sequentially overlapped from top to bottom. According to the thermal transfer ribbon, the white bonding layer is introduced into the thermal transfer ribbon structure, so that the expressive force and saturation of the color can be improved through the white bottom layer with high covering power, the high reflection performance of the white bonding layer is beneficial to improving the visual brightness of the whole pattern, the influence of the metal receptor color can be shielded, and the real representation of the pattern color is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal sublimation carbon ribbons, and in particular relates to a thermal sublimation foaming carbon ribbon and a preparation method thereof. Background Art

[0002] Traditional metal surface treatment technologies such as electroplating and painting are difficult to achieve complex patterns and high three-dimensional effects, and there are environmental pollution problems. Transfer technology is a new decorative means. Thermal sublimation carbon ribbon mainly achieves pattern printing by heating to sublimate the dye and transfer it to the surface of the receptor material. However, due to the special physical and chemical properties of the metal surface, such as high surface energy, smoothness and hardness, traditional thermal sublimation carbon ribbon is difficult to form a firm adhesion and ideal color effect on the metal surface. The color saturation after transfer is low, and it cannot present bright and vivid colors. The pattern lacks three-dimensional sense and is difficult to meet the requirements of modern decoration for layering and touch. At the same time, there is a defect of insufficient adhesion, which will cause the pattern to fall off and wear easily during use, affecting the appearance and service life of the product. However, some existing technologies use a single-layer foaming material combined with a pattern layer printed with ordinary ink to form a three-dimensional effect through heating and foaming, but this structure cannot guarantee the uniformity and stability of foaming, and is prone to local over-foaming or under-foaming, affecting the three-dimensional effect. At the same time, the combination between the ink and the foaming layer only relies on simple adhesion without special reinforcement measures. During use, the ink is easy to fall off or spread, reducing the clarity and aesthetics of the pattern. In addition, the combination of the transfer film and the metal surface usually adopts ordinary glue or adhesive, which has limited viscosity and is easy to fail under conditions of humidity, high temperature or friction, causing the transfer film to peel off from the metal surface. Summary of the invention

[0003] In order to solve the above technical problems, one of the objectives of the present invention is to provide a thermal sublimation foaming carbon tape that can be attached to the surface of a metal receptor and has high three-dimensional effect and high saturation.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a thermal sublimation foaming carbon tape, comprising a dye layer and a functional carbon tape layer arranged in sequence along the front-to-back direction, the upper end of the dye layer is coated with a primer layer, and the upper end of the primer layer is flush with the upper end of the functional carbon tape layer, the upper ends of the primer layer and the functional carbon tape layer are coated with a base film layer, and the upper end of the base film layer is coated with a back coating layer, wherein the functional carbon tape layer comprises a release layer, a foaming layer and a white adhesive layer stacked in sequence from top to bottom.

[0005] The thickness of the base film layer in the above technical solution is 4-125 μm (can be 4 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm and 125 μm, or any value or a range corresponding to any two values, preferably 4.3-12.5 μm), and the thickness of the back coating layer is 0.2-1 μm (can be 0.2 μm, 0.3 μm, , 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm and 1μm, or any value in the range between any two values, preferably 0.4-0.6μm), the thickness of the primer layer is 0.1-0.5μm (it can be any value in 0.1μm, 0.2μm, 0.3μm, 0.4μm and 0.5μm, or any value in the range between any two values, preferably 0.1-0.3μm), the thickness of the dye layer is The thickness of the release layer is 0.3-1 μm (it can be any value among 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm and 1 μm or a range corresponding to any two values, preferably 0.4-0.7 μm), and the thickness of the release layer is 0.5-5 μm (it can be any value among 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm and 5 μm or a range corresponding to any two values). The thickness of the foaming layer is 3-6μm (it can be any value among 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm and 6μm, or the range corresponding to any two values), and the thickness of the white adhesive layer is 3-6μm (it can be any value among 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm and 6μm, or the range corresponding to any two values).

[0006] The base film layer in the above technical solution meets at least one of the following conditions:

[0007] A1: The base film layer is made of polypropylene film, polyethylene naphthalate film, polyethylene terephthalate film, polyethylene film, polyvinyl alcohol film or polymethyl methacrylate film (preferably PET film);

[0008] B1: The side of the base film layer close to the back coating layer is surface treated to a dyne value > 38 before coating.

[0009] The preparation method of the back coating layer in the above technical solution is: dissolving the first resin, lubricant and solid filler in a first solvent to obtain a back coating layer coating, coating the back coating layer coating on the upper end of the base film layer, and then drying to obtain the back coating layer (the main function of the back coating layer is to adapt to the high-speed printing of the thermal sublimation printer, improve the heat resistance and lubricity of the base film layer, and ensure the heat transfer of the print head);

[0010] Wherein, the back coating meets at least one of the following conditions:

[0011] A2: the first resin is at least one of PVB resin, cellulose resin, silicone-modified polyurethane and polyamide resin;

[0012] B2: The lubricant includes at least one of metal soap, phosphate ester, silicone oil and release agent (the purpose of adding the lubricant is to improve the lubricity of the back coating layer so as to reduce friction damage to the print head during the printing process);

[0013] C2: The solid filler includes at least one of silica, talc and kaolin (the purpose of adding the solid filler is to solve the problem of material accumulation in the print head and further improve the lubricity of the back coating);

[0014] D2: the first solvent is butanone and / or toluene (preferably a butanone-toluene mixed solvent, the mass ratio of the two is 2-3:1);

[0015] E2: The amount of the first resin added to the back coating is 5-20wt% (can be any value among 5wt%, 10wt%, 15wt% and 20wt% or a range corresponding to any two values, preferably 8-15wt%), the amount of the first solvent added is 80-90wt% (can be any value among 80wt%, 82wt%, 84wt%, 6wt%, 88wt% and 90wt% or a range corresponding to any two values), the amount of the lubricant added is 10-40% of the weight of the first resin (can be any value among 10%, 20%, 30% and 40% or a range corresponding to any two values, preferably 20-30wt%), and the amount of the solid filler added is 1-5% of the weight of the first resin (can be any value among 1%, 2%, 3%, 4% and 5% or a range corresponding to any two values, preferably 3-5%).

[0016] The preparation method of the primer layer in the above technical solution is: dissolving the second resin in the second solvent to obtain a primer coating, coating the primer coating on the base film layer and drying to obtain the primer layer (the primer layer mainly functions to improve the adhesion and dispersibility of the dye layer on the base film layer, thereby improving the uniformity and color vividness of the printed image. During the printing process, the dye of the dye layer will diffuse in two opposite directions of the substrate and the primer layer when heated, so the primer layer is preferably selected from a material that has poor dye adsorption and excellent adhesion to the base film layer);

[0017] Wherein, the primer layer meets at least one of the following conditions:

[0018] A3: the second resin is at least one of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral and methyl cellulose;

[0019] B3: The second solvent is isopropanol;

[0020] C3: The amount of the second resin added to the base coating is 2-10wt% (it can be any value among 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% and 10wt% or a range corresponding to any two values, preferably 3-6wt%), and the amount of the second solvent added is 90-98wt% (it can be any value among 90wt%, 91wt%, 92wt%, 93wt%, 94wt%, 95wt%, 96wt%, 97wt% and 98wt% or a range corresponding to any two values).

[0021] The preparation method of the dye layer in the above technical solution is: dissolving the dye and the third resin in a third solvent to obtain a dye layer coating, coating the dye layer coating on the primer layer and drying to obtain the dye layer (the function of the dye layer is mainly to provide the dye in true color printing, and the dye is not particularly limited and can be selected from a variety of sublimation dyes, preferably a dye with low melting and sublimation temperature and good solubility);

[0022] Wherein, the dye layer meets at least one of the following conditions:

[0023] A4: The third resin is at least one of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methyl cellulose, polyurethane, polycarbonate or polyester resin;

[0024] B4: the third solvent is butanone and / or toluene (preferably a mixed solvent of butanone and toluene);

[0025] C4: The amount of the third resin added to the dye layer coating is 2-15wt% (can be any value among 2wt%, 5wt%, 10wt% and 15wt% or a range corresponding to any two values, preferably 2-5wt%), the amount of the third solvent added is 80-95wt% (can be any value among 80wt%, 85wt%, 90wt% and 95wt% or a range corresponding to any two values), and the mass ratio of the dye to the third resin is 1-2:1 (the ratio of the dye to the third resin in the dye layer can be adjusted according to the solubility of dyes of different colors and the color density to be achieved).

[0026] The preparation method of the release layer in the above technical solution is: dissolving the fourth resin in the fourth solvent to obtain a release layer coating, coating the release layer coating on the base film layer and drying to obtain the release layer (the release layer has two functions: one is to ensure the demoulding and edge cutting properties of the foaming layer and the white adhesive layer during printing; the other is to provide adhesion between the coating and the metal when the coating printed on the intermediate transfer medium is transferred to the metal);

[0027] Wherein, the release layer meets at least one of the following conditions:

[0028] A5: The fourth resin includes a first main resin, a first auxiliary resin, polyurethane and crystalline polyester, the first main resin is at least one of polyester resin, polyurethane resin, polycarbonate resin and acrylic resin, the first auxiliary resin is polyvinyl chloride, dichloroacetic acid, terchloroacetic acid, chloroether resin or vinyl chloride modified acrylic resin (the first auxiliary resin is mainly to ensure that the release layer and the foaming layer have good interlayer adhesion, and excellent adhesion with the metal), the addition amount of the first main resin in the release layer coating is 3-10wt% (it can be any value among 3wt%, 5wt% and 10wt% or the range corresponding to any two values), the first auxiliary resin in the release layer coating is 10wt% and 10wt% respectively. The amount of the resin added is 10-15wt% (can be any value among 10wt%, 11wt%, 12wt%, 13wt%, 14wt% and 15wt% or a range corresponding to any two values), the mass ratio of the polyurethane to the crystalline polyester is 1:1-9 (can be any ratio among 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 and 1:9 or a range corresponding to any two ratios), and the sum of the amounts of the polyurethane and the crystalline polyester added to the release layer coating is 2-5wt% (can be any value among 2wt%, 3wt%, 4wt% and 5wt% or a range corresponding to any two values);

[0029] B5: the fourth solvent is butanone and / or toluene;

[0030] C5: The added amount of the fourth solvent in the release layer coating is 70-90wt% (it can be any value among 70wt%, 75wt%, 80wt%, 85wt% and 90wt% or a range corresponding to any two values, preferably 75-80wt%).

[0031] The preparation method of the foaming layer in the above technical solution is: dissolving the fifth resin, foaming agent, dispersant and stabilizer in the fifth solvent to obtain a foaming layer coating, coating the foaming layer coating on the release layer and drying to obtain the foaming layer.

[0032] Wherein, the foaming layer meets at least one of the following conditions:

[0033] A6: The fifth resin includes a second main resin and a second auxiliary resin, the second main resin is at least one of an unsaturated polyester resin, a phenolic resin, an acrylic resin and an epoxy resin, the second auxiliary resin is a polyurethane resin, and the content of the second main resin in the fifth resin is 70-80wt% (can be any value of 70wt%, 72wt%, 74wt%, 76wt%, 78wt% and 80wt% or a range corresponding to any two values), and the balance is the second auxiliary resin;

[0034] B6: the fifth solvent is acetone and / or ethyl acetate;

[0035] C6: the foaming agent is azodicarbonamide;

[0036] D6: The dispersant is polyvinyl pyrrolidone;

[0037] E6: The stabilizer is calcium stearate;

[0038] F6: The amount of the fifth resin added to the foaming layer coating is 20-30wt% (can be any value among 20wt%, 22wt%, 24wt%, 26wt%, 28wt% and 30wt% or a range corresponding to any two values), the amount of the fifth solvent added is 70-80wt% (can be any value among 70wt%, 72wt%, 74wt%, 76wt%, 78wt% and 80wt% or a range corresponding to any two values), and the amount of the foaming agent added is 5% of the total amount of the fifth resin. -10% (can be any value among 5%, 6%, 7%, 8%, 9% and 10% or a range corresponding to any two values), the added amount of the dispersant is 1-3% of the total amount of the foaming agent (can be any value among 1%, 1.5%, 2%, 2.5% and 3% or a range corresponding to any two values), and the added amount of the stabilizer is 0.5-1.5% of the total amount of the fifth resin (can be any value among 0.5%, 0.7%, 0.9%, 1.1%, 1.3% and 1.5% or a range corresponding to any two values).

[0039] The preparation method of the white adhesive layer in the above technical solution is: dissolving the sixth resin, white pigment, adhesion promoter, curing agent and promoter in the sixth solvent to obtain a white adhesive layer coating, coating the white adhesive layer coating on the foaming layer and drying to obtain the white adhesive layer;

[0040] Wherein, the white adhesive layer meets at least one of the following conditions:

[0041] A7: The sixth resin is at least one of epoxy resin, polyurethane resin, acrylic resin, polyester resin, polyamide resin, cellulose resin, melamine resin, polyolefin resin and styrene resin;

[0042] B7: the sixth solvent is toluene and / or butanone;

[0043] C7: The white pigment is titanium dioxide;

[0044] D7: the adhesion promoter is at least one of a silane coupling agent, an organic titanate promoter, a zircon adhesion promoter and a phosphate compound;

[0045] E7: The curing agent is an amine curing agent, and the accelerator is an imidazole accelerator;

[0046] F7: The amount of the sixth resin added to the white adhesive coating is 15-30wt% (can be any value among 15, 20wt%, 25wt% and 30wt% or a range corresponding to any two values), the amount of the sixth solvent added is based on the viscosity of the white adhesive coating at 25°C being 100-500mPa·s (can be any value among 100mPa·s, 200mPa·s, 300mPa·s, 400mPa·s and 500mPa·s or a range corresponding to any two values, so as to ensure that the white adhesive coating has good fluidity during the coating process, evaporates in time during drying, and avoids residues affecting the performance of the foaming layer), the mass ratio of the sixth resin to the white pigment is 1:1-3 (can be any ratio among 1:1, 1:2 and 1:3 value or a range corresponding to any two ratios), the amount of the adhesion promoter added in the white adhesive coating is 1-5wt% (it can be any value among 1wt%, 2wt%, 3wt%, 4wt% and 5wt% or a range corresponding to any two values), the amount of the curing agent added in the white adhesive coating is 0.1-1wt% (it can be any value among 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% and 1wt% or a range corresponding to any two values), and the amount of the accelerator added is 5-10% of the weight of the curing agent (it can be any value among 5%, 6%, 7%, 8%, 9% and 10% or a range corresponding to any two values).

[0047] A second object of the present invention is to provide a method for preparing the thermal sublimation foaming carbon ribbon as described above, comprising the following steps:

[0048] Prepare back coating paint, primer coating paint, dye layer coating, release layer coating, foaming layer coating and white adhesive layer coating for later use;

[0049] Taking the base film layer, and performing surface treatment on the front side of the base film layer;

[0050] Applying a back coating layer on the front side of the base film layer and drying it to obtain a back coating layer;

[0051] Applying a primer coating and a release layer coating distributed in the front-to-back direction on the reverse side of the base film layer, and drying them to obtain a primer coating and a release layer respectively;

[0052] A dye layer coating is applied on the reverse side of the primer layer, and a foaming layer coating is applied on the reverse side of the release layer, followed by drying to obtain a dye layer and a foaming layer respectively;

[0053] A white adhesive layer coating is applied on the reverse side of the foaming layer and dried to obtain a white adhesive layer.

[0054] The beneficial effects of the present invention are as follows: the present invention introduces a white adhesive layer into the carbon ribbon structure, so that the color expression and saturation can be improved through the white bottom layer with high hiding power, and the high reflective performance of the white adhesive layer helps to improve the visual brightness of the overall pattern, and can also block the influence of the metal receptor color, ensuring the true reproduction of the pattern color (solving the problem of unclear images and texts caused by the inability of the pigment to cover the metal base color), and at the same time increasing the adhesion between the image and text part and the metal re-transfer film and the metal substrate;

[0055] The present invention provides a foaming layer in the carbon ribbon and uses a foaming agent to form a microscopic bubble structure, thereby enhancing the three-dimensional visual effect of the pattern and improving the surface adhesion performance. The presence of microscopic bubbles gives the pattern a concave-convex texture and increases the tactile effect, while the buffering performance of the foaming layer improves the impact resistance of the coating. The present invention optimizes the interlayer structure of the carbon ribbon to ensure the synergistic effect of each functional layer, thereby ensuring process compatibility and production efficiency while improving the decorative effect. The chemical compatibility and physical bonding force between the layers are the key to ensuring stability (the edge cutting property of the foaming layer can be improved by adding a release layer to achieve a finer printing effect).

[0056] The optimization of the manufacturing process of the thermal sublimation foaming carbon ribbon provided by the present invention reduces production costs and improves production efficiency;

[0057] The thermal sublimation foaming carbon ribbon provided by the present invention realizes the transfer of only the graphic part to the retransfer film by printing, so that the foaming effect only exists in the graphic part, avoiding the problem of poor three-dimensional effect caused by uneven heating of a single-layer foaming material. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the structure of the thermal sublimation foaming carbon ribbon described in an embodiment of the present invention.

[0059] In the figure: 1, back coating layer; 2, base film layer; 3, functional carbon tape layer; 31, release layer; 32, foaming layer; 33, white adhesive layer; 4, primer layer; 5, dye layer. DETAILED DESCRIPTION

[0060] The following will be combined with the embodiments to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0061] like Figure 1As shown, the present invention provides a thermal sublimation foaming carbon tape, comprising a dye layer 5 and a functional carbon tape layer 3 arranged in sequence along the front-to-back direction, a primer layer 4 is applied on the upper end of the dye layer 5, and the upper end of the primer layer 4 is flush with the upper end of the functional carbon tape layer 3, a base film layer 2 is applied on the upper ends of the primer layer 4 and the functional carbon tape layer 3, and a back coating layer 1 is applied on the upper end of the base film layer 2, wherein the functional carbon tape layer 3 comprises a release layer 31, a foaming layer 32 and a white adhesive layer 33 stacked in sequence from top to bottom.

[0062] First, the foaming layer and the white adhesive layer in this embodiment are specifically introduced:

[0063] Foam layer:

[0064] The main functions of the foaming layer are as follows: First, through the microscopic bubble structure, the three-dimensional and layered sense of the pattern is enhanced from a visual perspective, and with the white adhesive layer and the dye layer, a realistic and impactful three-dimensional visual effect is created. In terms of touch, the bubble structure gives the pattern a concave and convex texture, further increasing the three-dimensional sense of the product; second, it can improve the surface adhesion performance, the microscopic bubbles increase the surface area and roughness, strengthen physical adsorption and mechanical bite, ensure the long-term and firm bonding of the transferred pattern with each layer and the metal surface, and enhance the durability of the decoration; third, it can increase the cushioning performance of the product. When the metal product is impacted, the gas in the bubble compresses and absorbs the dispersed energy, protecting the decorative layer and the metal product, improving the product's impact resistance, and extending its service life.

[0065] In order to ensure excellent bonding strength between the foaming layer and the adjacent two layers, provide stable structural support for the microscopic bubbles in the foaming layer, and have good thermal stability and chemical stability, the second main resin can be selected from unsaturated polyester resin, phenolic resin, acrylic resin or epoxy resin, among which epoxy resin is preferred, which has good bonding properties and can be tightly combined with other ingredients (such as foaming agent, dispersant and stabilizer, etc.) to form a stable resin system. It has a high hardness after curing, which provides the necessary structural strength for the foaming layer, so that the foaming layer can still maintain a certain shape stability after forming a microscopic bubble structure, and will not be excessively deformed or lose support due to the presence of bubbles. The molecular weight of the epoxy resin is preferably between 4000-8000, and this molecular weight range can take into account its fluidity and mechanical properties.

[0066] In order to effectively prevent the foaming layer from cracking or peeling, ensure the integrity of the transfer pattern and the durability of the decorative effect, a certain amount of second auxiliary resin, such as polyurethane resin, can be added to the foaming layer. It can give the foaming layer a certain deformation ability, so that it can better adapt to the slight deformation of metal products during use, such as deformation caused by temperature changes, external forces, etc.; at the same time, it provides better wear resistance for the foaming layer, protects the foaming layer and the internal microscopic bubble structure, reduces damage caused by friction, extends the service life of the foaming layer, and maintains its various properties stable. The polyurethane selects a type with a glass transition temperature (Tg) between -30°C and 0°C, so that it maintains good elasticity and flexibility at room temperature. The amount of the fifth resin added to the foaming layer coating is 20-30wt%, of which the content of the second main resin in the fifth resin is 70-80wt%, and the balance is the second auxiliary resin.

[0067] In order to form a microscopic bubble structure, azodicarbonamide is selected as a foaming agent, and the amount used is 5-10% of the total mass of the fifth resin. This amount can ensure the generation of sufficient and uniform bubbles to achieve ideal stereoscopic vision, surface adhesion and buffering effects. Further, in order to ensure that the foaming agent is evenly dispersed in the fifth resin, a dispersant such as polyvinyl pyrrolidone is added in an amount of 1-3% of the mass of the foaming agent. At the same time, calcium stearate is added as a stabilizer in an amount of 0.5-1.5% of the total mass of the fifth resin to improve the stability of the bubble structure and prevent the bubbles from breaking or merging during the curing process, thereby improving the trimming performance of the product.

[0068] In order to ensure that all components are evenly mixed to form a uniform and stable system, the fifth solvent is a mixed solvent of acetone and ethyl acetate (mass ratio is 1-2:1). The amount of the fifth solvent is based on adjusting the viscosity of the foaming layer coating to an appropriate range, so that the viscosity of the foaming layer coating is maintained at 100-500mPa·s at 25°C (it can be any value among 100mPa·s, 200mPa·s, 300mPa·s, 400mPa·s and 500mPa·s or the corresponding range between any two values). In order to ensure that the foaming layer coating has good fluidity during the coating process, it evaporates in time during drying to avoid residual affecting the performance of the foaming layer. The amount of the fifth solvent added to the foaming layer coating is 70-80wt% of the total mass.

[0069] The recommended thickness range of the foaming layer is 3-6μm. Within this thickness range, a good balance can be achieved in terms of enhancing the three-dimensional visual effect, improving the surface adhesion performance, increasing the tactile effect, improving the impact resistance and improving the cutting performance. White adhesive layer:

[0070] The white adhesive layer is a mixture of high-hiding white pigment and the sixth resin (bonding resin). The white pigment needs to have high whiteness, high hiding power and good chemical stability, and the sixth resin needs to have excellent adhesion and thermal stability. The main functions of the white adhesive layer are to reflect light, increase the light reflectivity, and provide a brighter base color for the upper color layer, thereby significantly improving the color saturation, making the color of the transferred pattern more vivid, fuller, and richer in layers; second, to provide adhesion between the carbon ribbon and the intermediate transfer medium, i.e., the retransfer film, thereby improving the interlayer adhesion between the image and the retransfer film, so that the finished product after transfer has better adhesion and higher wear resistance and durability; third, to further ensure the trimming performance of the foaming layer and improve the fineness of the transferred image.

[0071] Titanium dioxide with high hiding power, good weather resistance and high chemical stability is selected as the white pigment. Titanium dioxide has a high refractive index and can efficiently reflect light, so that the white adhesive layer presents a bright white effect, provides a good foil for the color of the dye layer, and significantly improves the color saturation. It has strong hiding power and can effectively cover the color and surface texture of the metal receptor to ensure that the color of the dye layer is purer and brighter. The titanium dioxide is preferably rutile titanium dioxide, which has higher weather resistance and chemical stability and is suitable for maintaining the performance of the white adhesive layer under long-term use and different environmental conditions. The particle size of titanium dioxide needs to be strictly controlled. Generally, titanium dioxide with an average particle size of 100-300nm is selected, preferably 230-280nm. The appropriate particle size helps to evenly disperse the white pigment in the sixth resin, improve the optical uniformity of the white adhesive layer, and avoid uneven light scattering caused by agglomeration of the white pigment, thereby further optimizing the color reflection effect.

[0072] The sixth resin needs to be able to be fully mixed with the white pigment to form a uniform and stable white adhesive layer coating, and to be tightly combined with the foaming layer to ensure the firmness of the white adhesive layer in the functional carbon tape layer structure; at the same time, its flexibility can adapt to the deformation caused by the expansion and contraction of the foaming layer to prevent the white adhesive layer from cracking or peeling. The sixth resin is suitably formed by selecting existing well-known resin types, for example: epoxy resin, polyurethane resin, acrylic resin, polyester resin, polyamide resin, cellulose resin, melamine resin, polyolefin resin and styrene resin, etc. It is preferred to use a polyester-acrylic copolymer with good compatibility with titanium dioxide, strong adhesion and certain flexibility as the bonding resin. The polyester component gives the sixth resin good hardness, heat resistance and chemical stability, so that it can be used in high-temperature thermal transfer processes and It can maintain structural stability in complex environments and is not easily corroded by chemical substances, providing a solid basic performance for the white adhesive layer, while the acrylic component brings excellent flexibility and bonding properties to the resin, enhancing the interaction between the white adhesive layer and the various layers. The polyester content in the sixth resin is controlled at 60-70wt%, and the acrylic content is the remainder. Its Tg (glass transition temperature) is 70-95°C and its molecular weight is between 20000-50000. It can achieve a good balance in hardness, flexibility, heat resistance and bonding properties. At this ratio, the sixth resin can not only ensure that the white adhesive layer has sufficient strength and stability, but also has good flexibility and bonding properties. The amount of the sixth resin added in the white adhesive layer is 15-30wt%, and the ratio of the sixth resin to the white pigment is preferably 1:1-3.

[0073] Furthermore, in order to enhance the adhesion of the white adhesive layer to the metal re-transfer film and the metal surface, a certain amount of adhesion promoter may be added to the white adhesive layer, such as silane coupling agent, organic titanate promoter, zircon adhesion promoter or phosphate compound, etc. Preferably, a silane coupling agent is added, and its molecular structure contains both hydrolyzable alkoxy groups and organic functional groups. During the preparation of the white adhesive layer coating, the alkoxy groups undergo hydrolysis reaction under the action of water to generate silanol groups (Si-OH), which can undergo condensation reaction with hydroxyl groups (-OH) on the metal surface to form a strong chemical bond, thereby significantly enhancing the adhesion between the white adhesive layer and the metal surface. At the same time, the organic functional groups (such as amino groups) of the silane coupling agent interact with the molecular chains of the sixth resin to improve the affinity of the sixth resin to the metal receptor surface, further optimizing the overall bonding effect, and ensuring that the white adhesive layer can be tightly attached to the metal receptor surface after thermal transfer. The amount of adhesion promoter added to the white adhesive layer is 1-5wt%, preferably 1.5-3wt%. When the amount is too small, the silane coupling agent cannot fully exert its coupling effect, resulting in the adhesion between the white adhesive layer and the metal receptor surface not being significantly improved, affecting the transfer effect and decorative durability of the functional carbon ribbon layer on the metal retransfer film; excessive amount may cause the silane coupling agent to agglomerate itself, affecting its dispersibility in the sixth resin, thereby reducing the overall performance of the white adhesive layer, and having an adverse effect on its flexibility, transparency and bonding performance with other layers.

[0074] In order to improve the curing speed and cross-linking density of the white adhesive layer, further enhance its bonding strength and heat resistance, ensure that after the thermal transfer is completed, the white adhesive layer can quickly cure and form a stable bonding structure, so that the bonding between the functional carbon ribbon layer and the metal re-transfer film and the metal receptor surface is more firm and lasting, an appropriate amount of curing agent and accelerator can be added to accelerate the curing reaction of the sixth resin. Amine curing agents (such as diethylenetriamine) can be used as curing agents, which react with active groups in polyester-acrylic copolymer resins to promote cross-linking and curing of molecular chains to form a stable three-dimensional network structure, improve hardness, heat resistance and chemical stability, and ensure the structural integrity and performance of the white adhesive layer during thermal transfer. The accelerator can be imidazole accelerators (such as 2-methylimidazole), which cooperate with the curing agent to accelerate the curing reaction, improve production efficiency without affecting other properties, and ensure that the transfer pattern is firmly attached. Too much curing agent will affect the bonding performance of the functional carbon ribbon layer, while too little curing agent will lead to reduced trimming and printing fineness. The amount of curing agent added to the white adhesive layer is 0.1-1wt%, preferably 0.2-0.5wt%; the amount of accelerator added is 5-10% of the mass of the curing agent.

[0075] Furthermore, the sixth solvent is a mixed solvent of toluene and butanone (mass ratio is 1:1), which has strong solubility and moderate volatilization rate, can accurately adjust the performance parameters of the white adhesive layer coating system, meet the preparation and coating process requirements of the white adhesive layer coating, and has low cost and environmental friendliness. The amount of the sixth solvent needs to be strictly controlled so that the viscosity of the white adhesive layer coating is maintained at 100-500mPa·s at 25°C, thereby ensuring the coating quality and ensuring that the white adhesive layer has the best effect in color enhancement, bonding performance and working in coordination with the functional carbon ribbon layer.

[0076] Furthermore, in order to achieve a better balance of various functions and ensure the optimal effect in terms of color saturation, adhesion, foaming layer cutting performance and image fineness, the thickness of the white adhesive layer is controlled at 3-6μm. When the thickness is less than 3μm, the low pigment content affects the light reflection and color saturation, and cannot cover up the defects of the foaming layer, and the insufficient bonding points affect the adhesion and image fineness; when the thickness is greater than 6μm, although the light reflection ability may be enhanced, the coating difficulty and cost are increased, affecting the flexibility, adhesion and foaming layer cutting performance of the thermal sublimation foaming carbon ribbon.

[0077] The following is a comparative test of the performance of the thermal sublimation foaming carbon ribbon in the present invention in combination with the embodiments and comparative examples, wherein the air distribution of the base film layer, back coating layer, primer layer and dye layer in each embodiment and comparative example is not changed (the content in the square brackets after the material name in the following embodiments and comparative examples is the product manufacturer and / or model information):

[0078] Basement membrane layer:

[0079] Use PET film with a thickness of 4.3μm, the manufacturer is Anhui Tongai;

[0080] The back coating material formula is as follows:

[0081] 3 parts of polyvinyl butyral (B265H-B Guangzhou Hongshang) (as the first resin);

[0082] Cellulose acetate butyrate (CAB393-3, Eastman, USA) 7 parts (as the first resin);

[0083] Isocyanate ( MD I-50 Wanhua Chemical) 2.5 parts (as lubricant);

[0084] 0.2 parts of silicone oil (KF-6001 Shin-Etsu silicone) (as a lubricant);

[0085] 0.5 parts of talcum powder (LJ-320 Liangjiang Chemical) (as solid filler);

[0086] 57.8 parts of 2-butanone (as the first solvent);

[0087] 29 parts of toluene (as the first solvent);

[0088] The back coating material (grinded for 20 minutes using a sander) was then coated using a gravure coater with a coating thickness of 0.5 μm.

[0089] The basecoat paint formula is as follows:

[0090] 2 parts of polyvinyl pyrrolidone (industrial grade PVP K90 Guangdong Yuemei Chemical) (as the second resin);

[0091] 2 parts of polyvinyl alcohol (Tianjin Damao Chemical) (as the second resin);

[0092] 96 parts of isopropanol (as the second solvent);

[0093] The primer coating material was applied using a gravure coater with a coating thickness of 0.2 μm.

[0094] Dye layer (dyes are yellow, magenta and cyan dyes):

[0095] The formula for the yellow paint is as follows:

[0096] Polyurethane (901H Wanhua Chemical) 3 parts (as the third resin);

[0097] Solvent Yellow 2 (Henan Wokas Biotechnology) 3.6 parts (as dye);

[0098] Polymethyl methacrylate (CM 205, Chimei, Taiwan) 0.03 parts (as an auxiliary agent to provide the dye layer with anti-stickiness during printing and winding);

[0099] 46.68 parts of 2-butanone (as the third solvent);

[0100] 46.68 parts of toluene (as the third solvent);

[0101] The yellow paint was applied using a gravure coater with a coating thickness of 0.6 μm;

[0102] The recipe for magenta paint is as follows:

[0103] Polyurethane (901H Wanhua Chemical) 3.2 parts (as the third resin);

[0104] Solvent Red 24 (Sinopharm Chemical Reagent) 4.8 parts (as dye);

[0105] Polymethyl methacrylate (CM 205, Chimei, Taiwan) 0.03 parts (as an auxiliary agent to provide the dye layer with anti-stickiness during printing and winding);

[0106] 45.98 parts of 2-butanone (as the third solvent);

[0107] 45.98 parts of toluene (as the third solvent);

[0108] The magenta coating was applied using a gravure coater, with a coating thickness of 0.6 μm.

[0109] The formula for cyan paint is as follows:

[0110] Polyurethane (901H Wanhua Chemical) 4 parts (as the third resin);

[0111] 6 parts of solvent blue 36 (Nanjing Kangmanlin Chemical Industry) (as dye);

[0112] Polymethyl methacrylate (CM 205, Chimei, Taiwan) 0.03 parts (as an auxiliary agent to provide the dye layer with anti-stickiness during printing and winding);

[0113] 44.98 parts of 2-butanone (as the third solvent);

[0114] 44.98 parts of toluene (as the third solvent);

[0115] The magenta coating was applied using a gravure coater, with a coating thickness of 0.6 μm.

[0116] Example 1

[0117] The formula of the release layer coating is as follows:

[0118] 5 parts of acrylic resin (WH3360 Golden Li) (as the first main resin);

[0119] Chloroether resin (MP35 BASF) 12.5 parts (as the first auxiliary resin);

[0120] Polyurethane (F0411 Yoshida) 0.35 parts;

[0121] Crystalline polyester (S3049 Shanghai Shuyu Chemical) 2.95 parts;

[0122] 39.7 parts of 2-butanone (as the fourth solvent);

[0123] 39.7 parts of toluene (as the fourth solvent);

[0124] The release layer coating was applied using a gravure coater with a coating thickness of 1 μm.

[0125] The formula of the foaming layer coating is as follows:

[0126] Epoxy resin (128 Nanya) 18.75 parts (as the second main resin);

[0127] 6.25 parts of polyurethane elastomer (Desmopan 385 Bayer, Germany) (as the second auxiliary resin);

[0128] 2.5 parts of azodicarbonamide (as a foaming agent);

[0129] 0.04 parts of polyvinyl pyrrolidone (as a dispersant);

[0130] 0.25 parts of calcium stearate (as a stabilizer);

[0131] 43.63 parts of acetone (as the fifth solvent);

[0132] 29.08 parts of ethyl acetate (as the fifth solvent);

[0133] The foaming layer coating is coated by a gravure coater, and the coating thickness is 4 μm.

[0134] The formula of the white adhesive coating is as follows:

[0135] 15 parts of polyester-acrylic acid copolymer resin (CN9011 Sartomer) (as the sixth resin);

[0136] Titanium dioxide (DuPont R-902+) 15 parts (as white pigment);

[0137] Silane coupling agent (γ-aminopropyltriethoxysilane, Dow Corning Z-6020) 2 parts (as adhesion promoter);

[0138] Amine curing agent (diethylenetriamine, BASF DA) 0.2 parts (as curing agent);

[0139] Imidazole accelerator (2-methylimidazole, domestic industrial grade) 0.02 parts (as accelerator);

[0140] 33.9 parts of toluene (as the sixth solvent);

[0141] 33.9 parts of butanone (as the sixth solvent);

[0142] The white adhesive coating was applied by a slot coater with a thickness of 4 μm.

[0143] Example 2

[0144] Same as Example 1, except that the formula of the white adhesive coating is as follows:

[0145] 20 parts of polyester-acrylic acid copolymer resin (CN9011 Sartomer) (as the sixth resin);

[0146] Titanium dioxide (DuPont R-902+) 10 parts (as white pigment);

[0147] Silane coupling agent (γ-aminopropyltriethoxysilane, Dow Corning Z-6020) 2 parts (as adhesion promoter);

[0148] Amine curing agent (diethylenetriamine, BASF DA) 0.2 parts (as curing agent);

[0149] Imidazole accelerator (2-methylimidazole, domestic industrial grade) 0.02 parts (as accelerator);

[0150] 33.9 parts of toluene (as the sixth solvent);

[0151] 33.9 parts of butanone (as the sixth solvent);

[0152] The white adhesive coating is applied by a slot coater with a thickness of 4 μm.

[0153] Example 3

[0154] Same as Example 1, except that the formula of the white adhesive coating is as follows:

[0155] 22.5 parts of polyester-acrylic acid copolymer resin (CN9011 Sartomer) (as the sixth resin);

[0156] Titanium dioxide (DuPont R-902+) 7.5 parts (as white pigment);

[0157] Silane coupling agent (γ-aminopropyltriethoxysilane, Dow Corning Z-6020) 2 parts (as adhesion promoter);

[0158] Amine curing agent (diethylenetriamine, BASF DA) 0.2 parts (as curing agent);

[0159] Imidazole accelerator (2-methylimidazole, domestic industrial grade) 0.02 parts (as accelerator);

[0160] 33.9 parts of toluene (as the sixth solvent);

[0161] 33.9 parts of butanone (as the sixth solvent);

[0162] The white adhesive coating was applied by a slot coater with a thickness of 4 μm.

[0163] Example 4

[0164] Same as Example 1, except that the formula of the foaming layer coating is as follows:

[0165] Epoxy resin (128 Nanya) 18.75 parts (as the second main resin);

[0166] 6.25 parts of polyurethane elastomer (Desmopan 385 Bayer, Germany) (as the second auxiliary resin);

[0167] 1.25 parts of azodicarbonamide (as a foaming agent);

[0168] 0.04 parts of polyvinyl pyrrolidone (as a dispersant);

[0169] 0.25 parts of calcium stearate (as a stabilizer);

[0170] 43.5 parts of acetone (as the fifth solvent);

[0171] 29 parts of ethyl acetate (as the fifth solvent);

[0172] The foaming layer coating is coated by a gravure coater, and the coating thickness is 4 μm.

[0173] Comparative Example 1:

[0174] Same as Example 1, but without release layer.

[0175] Comparative Example 2:

[0176] Same as Example 1, but without the foaming layer.

[0177] Comparative Example 3:

[0178] Same as Example 1, but without the white adhesive layer.

[0179] Performance Test:

[0180] Evaluation of stereoscopic visual effect: The height difference and surface roughness of the transferred pattern are measured by a professional optical profilometer to evaluate the stereoscopic effect. The greater the height difference and the more the surface roughness conforms to the design expectations, the better the stereoscopic visual effect. The height difference (relief feeling) uses a high-precision profilometer to measure the vertical height difference between the raised part of the transfer pattern and the surrounding plane, in microns (μm). The height difference at multiple different positions is measured, and the average value is taken as the height difference index of the pattern. The surface roughness (microtexture) is scanned and analyzed by an atomic force microscope (AFM) or a laser confocal microscope to obtain the surface roughness parameter Ra (arithmetic mean roughness) in nanometers (nm). Ra reflects the average height deviation of the surface microscopic profile.

[0181] The stereoscopic effect is evaluated according to ABC, A for good stereoscopic effect, B for average stereoscopic effect, and C for poor stereoscopic effect. Both standards must be met during the evaluation. If the evaluation levels of the two standards are inconsistent, the lower level will be recorded.

[0182] The evaluation criteria for each level of stereoscopic effect are shown in Table 1:

[0183] Table 1 Evaluation criteria for each level of stereoscopic effect

[0184] grade A B C Height difference (μm) ＞20 10-20 ＜10 Surface roughness Ra(nm) ＜50 50-90 ＞90

[0185] Surface adhesion performance test: The hundred-grid test method is used. A cutting tool is used to draw grids with a horizontal and vertical spacing of 1mm on the surface of the transferred metal sample. Then the tape is pasted and quickly torn off to observe the shedding of the coating inside the grid. The smaller the shedding area, the better the adhesion performance.

[0186] The adhesion performance was evaluated according to ABC, with A being good adhesion, B being fair adhesion, and C being poor adhesion.

[0187] The evaluation criteria for each level of adhesion performance are shown in Table 2:

[0188] Table 2 Evaluation criteria for each level of adhesion performance

[0189]

[0190] Color density test: After printing CMY three-color pure color blocks and transferring them to the metal substrate, use the X-Rite i 1Pro 3 colorimeter to measure the color density of the transferred pattern. The higher the color density, the higher the saturation. The color density performance is evaluated according to ABC, A for OD>1.5, B for 1≤OD≤1.5, and C for OD<1.

[0191] Cutting edge test: Print a test pattern with fine lines (5mm line width) and small characters (such as 20pt font) on the metal sample, and observe the clarity of the line edges and the legibility of the characters with the naked eye under a microscope (magnification of 20-50 times). The cutting edge is good if the line edges are clear and the characters are completely legible.

[0192] The cutting performance is evaluated according to ABC, A for good cutting performance, B for average cutting performance, and C for poor cutting performance. Both standards must be met during the evaluation. If the evaluation levels of the two standards are inconsistent, the lower level will be recorded.

[0193] The evaluation criteria for each level of cutting edge performance are shown in Table 3:

[0194] Table 3 Evaluation criteria for each level of cutting edge performance

[0195]

[0196] The performance test items of each embodiment and comparative example mainly include stereoscopic visual effect evaluation, surface adhesion performance test, color density test and edge cutting test. The test results are shown in Table 4:

[0197] Table 4 Performance test table of each embodiment and comparative example 1

[0198] project Stereo Effect Adhesion Color Density Cutting edge Example 1 A A A A Example 2 A A B A Example 3 A A B B Example 4 B A A A Comparative Example 1 B A A C Comparative Example 2 C A A A Comparative Example 3 B C C C

[0199] It can be seen that the introduction of a white adhesive layer in the thermal sublimation foaming carbon ribbon can enhance the color expression and saturation through the high hiding power of the white bottom layer. The high reflective performance of the white adhesive layer helps to enhance the visual brightness of the overall pattern and block the influence of the metal receptor color to ensure the true reproduction of the color. The addition of a foaming layer can use a foaming agent to form a micro bubble structure, thereby enhancing the three-dimensional visual effect of the pattern and improving the surface adhesion performance. The presence of micro bubbles gives the pattern a concave and convex texture and increases the tactile effect. The cushioning performance of the foaming layer improves the impact resistance of the transferred pattern. The provision of a release layer can ensure the demoulding and cutting properties of the foaming layer and the white adhesive layer during printing.

[0200] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A thermal sublimation foaming carbon ribbon, characterized in that: It includes a dye layer and a functional carbon tape layer arranged in sequence along the front-to-back direction, the upper end of the dye layer is coated with a primer layer, and the upper end of the primer layer is flush with the upper end of the functional carbon tape layer, the upper ends of the primer layer and the functional carbon tape layer are coated with a base film layer, and the upper end of the base film layer is coated with a back coating layer, wherein the functional carbon tape layer includes a release layer, a foaming layer and a white adhesive layer stacked in sequence from top to bottom.

2. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The thickness of the base film layer is 4-125 μm, the thickness of the back coating layer is 0.2-1 μm, the thickness of the primer layer is 0.1-0.5 μm, the thickness of the dye layer is 0.3-1 μm, the thickness of the release layer is 0.5-5 μm, the thickness of the foaming layer is 3-6 μm, and the thickness of the white adhesive layer is 3-6 μm.

3. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The base film layer meets at least one of the following conditions: A1: The material of the base film layer is polypropylene film, polyethylene naphthalate film, polyethylene terephthalate film, polyethylene film, polyvinyl alcohol film or polymethyl methacrylate film; B1: The side of the base film layer close to the back coating layer is surface treated to a dyne value > 38 before coating.

4. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The back coating layer is prepared by: dissolving a first resin, a lubricant and a solid filler in a first solvent to obtain a back coating layer, coating the back coating layer on the upper end of the base film layer, and then drying to obtain the back coating layer; Wherein, the back coating meets at least one of the following conditions: A2: the first resin is at least one of PVB resin, cellulose resin, silicone-modified polyurethane and polyamide resin; B2: The lubricant includes at least one of metal soap, phosphate ester, silicone oil and release agent; C2: The solid filler comprises at least one of silica, talc and kaolin; D2: the first solvent is butanone and / or toluene; E2: The amount of the first resin added to the back coating is 5-20wt%, the amount of the first solvent added is 80-90wt%, the amount of the lubricant added is 10-40% of the weight of the first resin, and the amount of the solid filler added is 1-5% of the weight of the first resin.

5. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The preparation method of the primer layer is: dissolving the second resin in the second solvent to obtain a primer coating, coating the primer coating on the base film layer and drying to obtain the primer layer; Wherein, the primer layer meets at least one of the following conditions: A3: the second resin is at least one of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral or methyl cellulose; B3: The second solvent is isopropanol; C3: The amount of the second resin added to the base coating is 2-10 wt%, and the amount of the second solvent added is 90-98 wt%.

6. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The preparation method of the dye layer is: dissolving the dye and the third resin in a third solvent to obtain a dye layer coating, coating the dye layer coating on the base coating and drying to obtain the dye layer; Wherein, the dye layer meets at least one of the following conditions: A4: The third resin is at least one of polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methyl cellulose, polyurethane, polycarbonate or polyester resin; B4: the third solvent is butanone and / or toluene; C4: The amount of the third resin added to the dye layer coating is 2-15wt%, the amount of the third solvent added is 80-95wt%, and the mass ratio of the dye to the third resin is 1-2:

1.

7. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The release layer is prepared by: dissolving a fourth resin in a fourth solvent to obtain a release layer coating, coating the release layer coating on the base film layer and drying to obtain the release layer; Wherein, the release layer meets at least one of the following conditions: A5: The fourth resin includes a first main resin, a first auxiliary resin, polyurethane and crystalline polyester, the first main resin is a polyester resin, a polyurethane resin, a polycarbonate resin or an acrylic resin, the first auxiliary resin is at least one of polyvinyl chloride, divinyl chloride, tervinyl chloride, chloroether resin and vinyl chloride modified acrylic resin, the addition amount of the first main resin in the release layer coating is 3-10wt%, the addition amount of the first auxiliary resin in the release layer coating is 10-15wt%, the mass ratio of the polyurethane to the crystalline polyester is 1:1-9, and the sum of the addition amounts of the polyurethane and the crystalline polyester in the release layer coating is 2-5wt%; B5: the fourth solvent is butanone and / or toluene; C5: The added amount of the fourth solvent in the release layer coating is 70-90wt%.

8. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The foaming layer is prepared by: dissolving a fifth resin, a foaming agent, a dispersant and a stabilizer in a fifth solvent to obtain a foaming layer coating, coating the foaming layer coating on the release layer and drying to obtain the foaming layer; Wherein, the foaming layer meets at least one of the following conditions: A6: The fifth resin includes a second main resin and a second auxiliary resin, wherein the second main resin is at least one of an unsaturated polyester resin, a phenolic resin, an acrylic resin and an epoxy resin, and the second auxiliary resin is a polyurethane resin. The content of the second main resin in the fifth resin is 70-80wt%, and the remainder is the second auxiliary resin; B6: the fifth solvent is acetone and / or ethyl acetate; C6: the foaming agent is azodicarbonamide; D6: The dispersant is polyvinyl pyrrolidone; E6: The stabilizer is calcium stearate; F6: The amount of the fifth resin added to the foaming layer coating is 20-30wt%, the amount of the fifth solvent added is 70-80wt%, the amount of the foaming agent added is 5-10% of the total amount of the fifth resin, the amount of the dispersant added is 1-3% of the total amount of the foaming agent, and the amount of the stabilizer added is 0.5-1.5% of the total amount of the fifth resin.

9. The thermal sublimation foaming carbon ribbon according to claim 1, characterized in that: The preparation method of the white adhesive layer is as follows: dissolving the sixth resin, white pigment, adhesion promoter, curing agent and promoter in the sixth solvent to obtain a white adhesive layer coating, coating the white adhesive layer coating on the foaming layer and drying to obtain the white adhesive layer; Wherein, the white adhesive layer meets at least one of the following conditions: A7: The sixth resin is at least one of epoxy resin, polyurethane resin, acrylic resin, polyester resin, polyamide resin, cellulose resin, melamine resin, polyolefin resin and styrene resin; B7: the sixth solvent is toluene and / or butanone; C7: The white pigment is titanium dioxide; D7: the adhesion promoter is at least one of a silane coupling agent, an organic titanate promoter, a zircon adhesion promoter and a phosphate compound; E7: The curing agent is an amine curing agent, and the accelerator is an imidazole accelerator; F7: The amount of the sixth resin added to the white adhesive coating is 15-30wt%, the amount of the sixth solvent added is based on the viscosity of the white adhesive coating at 25°C being 100-500mPa·s, the mass ratio of the sixth resin to the white pigment being 1:1-3, the amount of the adhesion promoter added to the white adhesive coating being 1-5wt%, the amount of the curing agent added to the white adhesive coating being 0.1-1wt%, and the amount of the promoter added being 5-10% of the weight of the curing agent.

10. A method for preparing a thermal sublimation foamed carbon ribbon as claimed in any one of claims 1 to 9, characterized in that: The steps include: Prepare back coating paint, primer coating paint, dye layer coating, release layer coating, foaming layer coating and white adhesive layer coating for later use; Taking the base film layer, and performing surface treatment on the front side of the base film layer; Applying a back coating layer on the front side of the base film layer and drying it to obtain a back coating layer; Applying a primer coating and a release layer coating distributed in the front-to-back direction on the reverse side of the base film layer, and drying them to obtain a primer coating and a release layer respectively; A dye layer coating is applied on the reverse side of the primer layer, and a foaming layer coating is applied on the reverse side of the release layer, followed by drying to obtain a dye layer and a foaming layer respectively; A white adhesive layer coating is applied on the reverse side of the foaming layer and dried to obtain a white adhesive layer.

Images