Thermal transfer ribbon with resin release layer with high substrate adaptability and preparation method of thermal transfer ribbon
By using a high substrate adaptive resin release layer in the thermal transfer carbon tape, the problem of poor transfer effect on different substrates in the prior art is solved, and better transfer integrity and pattern durability are achieved.
Patent Information
- Application Number
- CN202510109709.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-05-27
AI Technical Summary
It is difficult to achieve good transfer effect on different substrates for existing thermal transfer resin carbon tapes, especially on PVC tapes and silver reverse tapes of different background colors, which are prone to the problem of transfer loss.
The thermal transfer carbon tape of a high substrate adaptive resin release layer is used. The release layer consists of more than 40 wt% acrylic resin, 1-30 wt% wt% wt and the balance as a leveling agent. By adding methacrylic resin and leveling agent, the uniform heating and substrate adaptability of the release layer are improved.
A good transfer effect on different substrates is achieved, the problem of transfer loss is avoided, and the durability and solvent resistance of the pattern are improved.
Smart Images
Figure CN120039047A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of thermal transfer ribbons, and particularly relates to a thermal transfer ribbon with a resin release layer having high substrate adaptability and a preparation method thereof. Background Art
[0002] Thermal transfer printing refers to a printing method in which a ribbon with a transferable ink layer is heated by a print head through a thermal transfer printer, and the ink layer is transferred to a substrate. The pattern after resin ribbon transfer has both high durability and excellent solvent resistance, so it is widely used in the field of outdoor signs. At present, the release layers of resin ribbons used in the field of power signs are mostly prepared from synthetic wax. Such release layers are not only difficult to continuously and stably coat, but also difficult to simultaneously meet the transfer effects on different substrates such as PVC tapes and silver reverse tapes with different background colors. Due to the wide molecular weight distribution and melting range of synthetic wax, transfer omission is very likely to occur in some edge areas. Summary of the Invention
[0003] Aiming at the fact that the thermal transfer resin ribbons currently applied in the field of power signs are difficult to simultaneously meet the good transferability on substrates such as PVC tapes and silver reverse tapes with different background colors, the present invention provides a thermal transfer ribbon with a resin release layer having high substrate adaptability and a preparation method thereof. Based on the resin release layer with high substrate adaptability, the thermal transfer ribbon of the present invention has better continuous coatability while having high substrate adaptability.
[0004] The technical solutions provided by the present invention are as follows:
[0005] A thermal transfer ribbon with a resin release layer having high substrate adaptability, comprising an ink layer, a release layer, a substrate, and a back coating arranged in sequence, or comprising an adhesive layer, an ink layer, a release layer, a substrate, and a back coating arranged in sequence. The composition of the release layer is as follows: more than 40 wt% of acrylic resin, 1 - 30 wt% of wax, and the balance is a leveling agent.
[0006] In the above technical solution, synthetic wax can be added or not. Among them, when synthetic wax is added, the content of synthetic wax is less than 10 wt%, and it is only used as an auxiliary agent to improve scratch resistance. If the product has no scratch resistance requirement or the pattern is otherwise laminated, etc., synthetic wax may not be added.
[0007] The release layer in the above technical solution uses methyl methacrylate resin as the main film-forming resin and adds an appropriate amount of leveling agent. Such a release layer is more uniformly heated during the transfer process, so it has good substrate adaptability. After transfer, the high durability and low surface energy methyl methacrylate resin can protect the ink layer and further improve the durability of the pattern, and it can be well applied to power industry signs (PVC-based substrates) and traffic reflective signs (reflective film-based substrates).
[0008] The base material is a transparent flexible plastic film, such as polypropylene (PP), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene (PE), polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), etc. Among them, PET is preferred.
[0009] Furthermore, the thickness of the base material is preferably not less than 2 μm and not more than 15 μm, more preferably not less than 3 μm and not more than 6 μm. Thereby, the mechanical strength of the base material can be ensured, and at the same time, the heat energy during the thermal transfer process can be well transferred to the transfer layer.
[0010] The thermal transfer sheet of the present invention includes a transfer layer, which has a release layer, an ink layer, and an adhesive layer.
[0011] The release layer is located between the base material and the ink before printing, and is located on the side of the ink layer away from the substrate to be transferred after printing. During the thermal transfer process, it mainly helps the ink layer to detach from the base material. After being transferred into a pattern, it can form a dense film on the surface, improving the durability and solvent resistance of the pattern.
[0012] The release layer is composed of an acrylic resin, wax, and a leveling agent.
[0013] Furthermore, the release layer contains at least one acrylic resin with an average molecular weight (Mn) of not less than 10,000 and not more than 150,000. The Mn of the acrylic resin is preferably not less than 12,000 and not more than 60,000, more preferably not less than 15,000 and not more than 40,000, and particularly preferably not less than 18,000 and not more than 22,000.
[0014] Furthermore, the glass transition temperature of the acrylic resin is preferably not less than 65 °C and not more than 150 °C, more preferably not less than 85 °C and not more than 130 °C. Thereby, the adaptability to various PVC tapes and reflective film substrates can be further improved.
[0015] Furthermore, the content of the acrylic resin in the release layer is preferably not less than 40% and not more than 100%, more preferably not less than 60% and not more than 95%. Thereby, the protection effect on the pattern after transfer can be further improved.
[0016] Furthermore, the acrylic resin in the release layer includes one or more combinations of methyl methacrylate, acrylonitrile, ethyl acrylate, butyl acrylate, isooctyl acrylate, and isobutyl methacrylate.
[0017] Furthermore, the release layer may contain wax within the range that does not damage the characteristics of the present invention. Examples include microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, Japan wax, beeswax, spermaceti wax, white wax, wool wax, shellac wax, candelilla wax, and partially modified waxes. Among them, oxidized polyethylene wax is preferred.
[0018] Furthermore, by making the release layer contain wax, the friction resistance of the pattern after transfer using the thermal transfer sheet of the present invention can be improved.
[0019] Furthermore, the content of wax in the release layer is preferably 1% or more and 30% or less, more preferably 2% or more and 5% or less.
[0020] Furthermore, a leveling agent can be included in the release layer within the range that does not damage the characteristics of the present invention. Examples include common silicone leveling agents. By including a leveling agent, the stain resistance of the pattern can be further improved.
[0021] Furthermore, the thickness of the release layer is preferably 0.1 μm or more and 1 μm or less, more preferably 0.2 μm or more and 0.5 μm or less. Thus, the heat is more evenly distributed during the transfer process, so it has good substrate adaptability. After transfer, the high-durability and low-surface-energy methacrylic resin can protect the ink layer and further improve the durability of the pattern.
[0022] The method for preparing the release layer is as follows: Dissolve the acrylic resin in solvents such as toluene and methyl ethyl ketone. After the resin is completely dissolved, add a specified amount of oxidized polyethylene wax and a leveling agent, and stir well to obtain a release layer coating solution. Then, coat it on the surface of the substrate by gravure coating or slot coating and dry it. The drying temperature is 50 - 100°C, and the drying time is 5 - 60 s. Thus, the release layer of the present invention is obtained.
[0023] Preferably, the release layer coating solution is composed of 8.5 parts of acrylic resin, 1 part of oxidized polyethylene wax, 0.5 part of leveling agent, 45 parts of toluene, and 45 parts of methyl ethyl ketone by mass components.
[0024] The main components in the ink layer are one or more polyester resins and coloring materials.
[0025] The method for preparing the ink layer is to dissolve a certain amount of polyester resin in solvents such as methyl ethyl ketone and toluene, then add a certain amount of required pigments, add a certain amount of dispersant and grind to obtain an ink layer coating, and then coat it on the surface of the release layer by gravure coating or slot coating and dry and cure it. The drying temperature is 40 - 100°C, and the drying time is 5 - 60 s.
[0026] Preferably, the ink layer includes 50 - 70 wt% of polyester resin, 20 - 50 wt% of coloring materials, and 10 - 20 wt% of dispersion aids. The polyester resin can be selected from AH651, AH514, CL150, etc. of Hanhai New Materials.
[0027] Furthermore, the thickness of the ink layer is 0.7 - 1.2 microns.
[0028] The main component in the subsequent layer is at least one thermoplastic resin that softens upon heating to exhibit adhesiveness.
[0029] The preparation method of the subsequent layer is to dissolve a certain amount of one or more thermoplastic resins in solvents such as methyl ethyl ketone and toluene, and then coat it on the surface of the release layer by gravure coating or slot coating and dry and cure it. The drying and curing temperature is 80 - 100 °C, and the drying time is 5 - 60 s.
[0030] Furthermore, the thickness of the subsequent layer is 0.1 - 0.3 microns.
[0031] The function of the back coating is to conduct heat and prevent friction, and to protect the print head and the printing substrate.
[0032] Furthermore, the back coating resin is composed of one or more of polyurethane-modified silicone resin, acrylic acid-modified silicone resin, polyvinyl acetal resin, and polyvinyl butyral resin.
[0033] Furthermore, the thickness of the back coating is 0.2 - 1.0 μm.
[0034] The preparation method of the back coating is as follows: dissolve the above polymer materials in the corresponding solvents to form a coating, and then coat it on the side of the substrate away from the protective layer by gravure coating or slot coating and dry it. The drying temperature is 50 - 100 °C, and the drying time is 5 - 60 s.
[0035] The preparation method of the thermal transfer ribbon with a resin release layer having high substrate adaptability specifically includes the following steps:
[0036] 1) Corona is applied to both sides of the substrate;
[0037] 2) A layer of the above-mentioned back coating is coated on the substrate;
[0038] 3) A layer of the above-mentioned release layer is coated on the other side of the substrate;
[0039] 4) An ink layer is coated on the release layer;
[0040] 5) Another layer of the subsequent layer is coated on the ink layer.
[0041] For the thermal transfer ribbon with a resin release layer having high substrate adaptability provided by the present invention, the release layer uses methacrylic resin as the main film-forming resin and adds an appropriate amount of leveling agent. Such a release layer is more evenly heated during the transfer process, so it has good substrate adaptability. After transfer, the methacrylic resin with high durability and low surface energy can protect the ink layer to further improve the durability of the pattern. Description of the Drawings
[0042] Figure 1 It is a schematic structural diagram of a thermal transfer ribbon with a resin release layer having high substrate adaptability provided by the present invention.
[0043] Figure 2 It is a pattern printed on a white PVC tape using Example 1.
[0044] Appendix Figure 1 Among them, the list of structures represented by each label is as follows:
[0045] 1. Back coating; 2. Release layer; 3. Ink layer; 4. Adhesive layer; 5. Substrate. Specific embodiments
[0046] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0047] Unless otherwise specified, the test methods used in the examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, are reagents and materials that can be obtained through commercial channels.
[0048] In a specific embodiment, as Figure 1 shown, the thermal transfer ribbon with a resin release layer having high substrate adaptability includes an ink layer 3, a release layer 2, a substrate 5, and a back coating 1 arranged in sequence. Further, an adhesive layer 4 can be added to the bottom layer.
[0049] Examples
[0050] In Examples 1-5, the formulations of each release layer are as follows:
[0051]
[0052] In Examples 1-5, the raw materials of each ink layer coating solution are weighed according to the following ratios:
[0053]
[0054] In Examples 1-5, the raw materials of each adhesive layer coating solution are weighed according to the following ratios:
[0055] 10 parts of polyester resin (AH651 from Hanhai New Materials)
[0056] 30 parts of adhesive resin (adhesion promoter resin F-2P from Toyobo Co., Ltd. of Japan)
[0057] 30 parts of toluene
[0058] 30 parts of methyl ethyl ketone
[0059] In Examples 1-5, the following formula is used for each back coating solution:
[0060] 3 parts of polyurethane-modified silicone resin
[0061] 10 parts of acrylic-modified silicone resin
[0062] 5 parts of polyvinyl acetal resin
[0063] 2 parts of polyvinyl butyral resin
[0064] 20 parts of toluene
[0065] 60 parts of methyl ethyl ketone
[0066] In Examples 1-5, the carbon ribbon substrate is a PET substrate with a thickness of 4.3 μm.
[0067] The printing substrates in Examples 1-5 are white PVC tape, yellow PVC tape, silver reverse tape and reflective film respectively.
[0068] The preparation methods of the carbon ribbons in Examples 1-5 are as follows:
[0069] 1. Coating the release coating liquid on the substrate surface by gravure coating or slot coating and drying it. The drying temperature is 100 °C, the drying time is 35 s, and the release layer thickness is about 0.3 μm.
[0070] 2. Coating the ink layer coating liquid obtained by grinding on the release layer surface by gravure coating or slot coating and drying it. The drying temperature is 80 °C, the drying time is 35 s, and the ink layer thickness is about 0.95 μm.
[0071] 3. Dissolving a certain amount of back coating resin in solvents such as methyl ethyl ketone and toluene, then adding a certain amount of additives to obtain a back coating paint, and then coating it on the surface of the substrate on the side away from the release layer by gravure coating or slot coating and drying it. The drying temperature is 100 °C, the drying time is 35 s, and the back coating thickness is about 0.6 μm.
[0072] 4. Dissolving a certain amount of one or more thermoplastic resins of the adhesive layer in methyl ethyl ketone and toluene, and then coating it on the release layer surface by gravure coating or slot coating and drying and curing it. The drying and curing temperature is 100 °C, the drying time is 35 s, and the adhesive layer thickness is about 0.2 μm. The adhesive layer can be set or not set according to needs.
[0073] After obtaining the carbon ribbon, use a printing machine based on thermal transfer to print the adhesive layer, ink layer and release layer onto white PVC tape, yellow PVC tape, silver reverse tape and reflective film.
[0074] Comparative Example 1
[0075] Use the same ink layer, adhesive layer, and back coating formulation, coating thickness, coating method, and printing method as in Examples 1-5, but change the components in the release layer. By mass: 85 parts of polyethylene oxide wax and 15 parts of EVA resin.
[0076] Comparative Example 2
[0077] Use the same ink layer, adhesive layer, and back coating formulation, coating thickness, coating method, and printing method as in Examples 1-5, but change the components in the release layer. By mass: 85 parts of polyethylene wax (Sasol SP-30 with a relatively long melting range) and 15 parts of EVA resin.
[0078] Comparative Example 3
[0079] Use the same ink layer, adhesive layer, and back coating formulation, coating thickness, coating method, and printing method as in Examples 1-5, but change the components in the release layer by mass: 90 parts of carnauba wax and 10 parts of EVA resin.
[0080] Use the self-developed thermal transfer printer DTP-265I of the company, and use the resin carbon tape prepared in the example to transfer patterns on white PVC tape, yellow PVC tape, silver reverse tape, and reflective film, and observe the integrity of the transferred patterns.
[0081] Visually confirm the formed image and evaluate it according to the following evaluation criteria:
[0082] A: The image transfer is complete, there is no missing at the edge, and there is no blurring or white exposure on the image area.
[0083] B: There are slight missing in the image transfer, the edge transfer is slightly uneven, and there is white exposure on the image area.
[0084] C: The image transfer is significantly missing and the transfer quality is poor.
[0085] NG: The image cannot be transferred.
[0086] Performance comparison table of examples:
[0087] Base material Example 1 Example 2 Example 3 Example 4 Example 5 White PVC tape B A A A A Yellow PVC tape B A A A A Silver reflective tape C A B A B 3M Class V reflective film B A A A A 3M Class IV reflective film B A B A B
[0088] Performance comparison table of comparative examples:
[0089] Base material Comparative example 1 Comparative example 2 Comparative example 3 White PVC tape B B A Yellow PVC tape C C B Silver reflective tape C C B 3M Class V reflective film B A B 3M Class IV reflective film C B B
[0090] As Figure 2 shown, it is the pattern printed on the white PVC tape using Example 1. It can be seen from the figure that the present invention avoids defects such as a large number of unprinted white dots (caused by uneven coating of the synthetic wax release layer) and local blurring of the pattern (caused by uneven heating) that occur when printing such patterns.
[0091] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A thermal transfer carbon ribbon with a resin release layer having high substrate adaptability, comprising an ink layer, a release layer, a substrate and a back coating layer arranged in sequence, or comprising an adhesive layer, an ink layer, a release layer, a substrate and a back coating layer arranged in sequence, characterized in that: The release layer has the following composition: more than 40 wt % of acrylic resin, 1-30 wt % of wax, and the balance of leveling agent.
2. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 1, characterized in that: At least one of the acrylic resins is selected from acrylic resins with an average molecular weight of 10,000-150,000; the glass transition temperature of the acrylic resin is 65-150° C.; the content of the acrylic resin in the release layer is 60-95wt%; The wax includes, but is not limited to, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, Japan wax, beeswax, spermaceti wax, white wax, wool wax, shellac wax, and candelilla wax; the wax content in the release layer is 2-5 wt%; The leveling agent is an organic silicone leveling agent; The thickness of the release layer is 0.1-1 μm.
3. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 2, characterized in that: At least one of the acrylic resins is selected from acrylic resins having an average molecular weight of 12,000-60,000; the glass transition temperature of the acrylic resin is 85° C.-130° C.; The thickness of the release layer is 0.2-0.5 μm.
4. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 3, characterized in that: The acrylic resin is selected from any one or more of methyl methacrylate, acrylonitrile, ethyl acrylate, butyl acrylate, isooctyl acrylate or isobutyl methacrylate; at least one of the acrylic resins is selected from acrylic resins having an average molecular weight of 5000-40000; The wax is oxidized polyethylene wax.
5. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 1, characterized in that: The substrate includes, but is not limited to, transparent flexible polypropylene film, polyethylene naphthalate film, polyethylene terephthalate film, polyethylene film, polyvinyl alcohol film, polymethyl methacrylate film; the thickness of the substrate is 2-15 μm.
6. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 1, characterized in that: The ink layer includes 50-70 wt % of a polyester resin, 20-50 wt % of a coloring material, and 10-20 wt % of a dispersing aid.
7. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 1, characterized in that: The material of the adhesive layer is thermoplastic resin.
8. The thermal transfer carbon ribbon with a resin release layer having high substrate adaptability according to claim 1, characterized in that: The back coating layer resin is selected from any one or more of polyurethane modified silicone resin, acrylic modified silicone resin, polyvinyl acetal resin or polyvinyl butyral resin; the thickness of the back coating layer is 0.2-1.0 μm.
9. A method for preparing a thermal transfer carbon ribbon having a resin release layer with high substrate adaptability according to any one of claims 1 to 8, characterized in that: The following steps are involved: 1) applying corona to both sides of the substrate; 2) coating a layer of the back coating on the substrate; 3) coating a layer of the release layer on the other side of the substrate; 4) coating an ink layer on the release layer; 5) Apply an adhesive layer on top of the ink layer.
10. The preparation method according to claim 9, characterized in that: The drying temperature of the release layer is 50-100°C, and the drying time is 5-60s; The drying temperature of the ink layer is 40-100°C, and the drying time is 5-60s; The drying and curing temperature of the adhesive layer is 80-100°C, and the drying time is 5-60s; The back coating layer has a drying temperature of 50-100° C. and a drying time of 5-60 seconds.