A sublimation ribbon, re-transfer film, and transfer method suitable for PET card printing

Abstract

This invention relates to the field of thermal sublimation printing technology, specifically to a thermal sublimation ribbon, a re-transfer film, and a transfer method suitable for printing PET ID cards. The ribbon has a base coating layer on one side of the substrate, and a dye layer on the base coating layer; it also includes an adhesion promoting layer; the adhesion promoting layer includes a release layer and an adhesive layer, with the release layer disposed on one side of the substrate and the adhesive layer disposed on the release layer. When this ribbon is used in conjunction with the re-transfer film, the pattern can be printed onto the re-transfer film first through the dye layer, and then the adhesion promoting layer can be printed onto the pattern layer. The release layer ensures complete transfer of the adhesion promoting layer, and the adhesive layer improves the adhesion of the pattern to the PET ID card, increasing the color density and durability of the ID card image.

Description

Technical Field

[0001] This invention relates to the field of thermal sublimation printing technology, and more specifically, to a thermal sublimation ribbon, a re-transfer film, and a transfer method suitable for printing PET ID cards. Background Technology

[0002] Commonly used identification cards in daily life include: ID cards, social security cards, bank cards, membership cards, payment cards, points cards, student IDs, employee cards, conference cards, exhibition cards, parking cards, etc. Most of these are made of PVC, which is lightweight, heat-insulating, moisture-proof, flame-retardant, and easy to install. The existing manufacturing processes are mainly divided into two types. The first is inkjet printing, which prints images onto a PVC substrate and then uses a special adhesive film to seal both sides. However, current inkjet printing technology cannot achieve the image quality, especially for facial features, that meets the requirements of identification cards. The second type is thermal sublimation printing, which uses heat to transfer yellow, red, and blue pigments onto the printing medium. By controlling the temperature of the print head, different shades of color are obtained, and the three colors are superimposed to form continuous color gradations. This method produces a more refined print quality compared to inkjet printing.

[0003] However, PVC has the following problems compared to PET for ID cards: 1. PVC is less environmentally friendly, while PET is a recyclable material; 2. PVC is inferior in terms of abrasion resistance, solvent resistance, and gloss. PET material, due to its good abrasion resistance, folding resistance, solvent resistance, and non-toxic and odorless properties, is used for the production of high-end customized ID cards and legal documents.

[0004] Dye-sublimation printing technology is often used to replace traditional photo printing because it can achieve continuous color gradations. Currently, there are products on the market that directly apply dye-sublimation ribbons to ID card printing, but they have the following main problems: 1. Dye-sublimation ribbon image printing requires a special dye receiving coating, otherwise the color concentration is very low; 2. The dye layer formed directly on the ID card through dye-sublimation has poor abrasion resistance and weather resistance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a sublimation ribbon, a re-transfer film and a transfer method suitable for printing PET ID cards.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a sublimation ribbon suitable for printing PET ID cards, comprising a substrate, a base coating layer on one side of the substrate, and a dye layer on the base coating layer; it also includes an adhesion promoting layer; the adhesion promoting layer includes a release layer and an adhesive layer, the release layer being disposed on one side of the substrate, and the adhesive layer being disposed on the release layer.

[0008] Furthermore, the release layer comprises the following components, and the mass fraction of each component is: 10-30 parts of the first resin and 70-90 parts of the first organic solvent;

[0009] The first resin is a mixture of vinyl chloride-vinyl acetate copolymer and polyurethane, wherein the mass of vinyl chloride-vinyl acetate copolymer accounts for 70% to 90% of the total mass of the first resin, and the mass of polyurethane accounts for 10% to 30% of the total mass of the first resin.

[0010] Furthermore, the release layer also includes a functional material, the mass percentage of which is 1% to 2.5% of the total mass of the first resin;

[0011] The functional materials include one or more of the following: fillers, plasticizers, antistatic materials, ultraviolet absorbing materials, inorganic microparticles, organic microparticles, release agents, and dispersion materials.

[0012] Furthermore, the adhesive layer comprises 20-40 parts by weight of a second resin and 60-80 parts by weight of a second organic solvent;

[0013] The second resin comprises a thermoplastic resin and a vinyl chloride-vinyl acetate copolymer, wherein the thermoplastic resin accounts for 30% to 80% of the total mass of the second resin, and the vinyl chloride-vinyl acetate copolymer accounts for 20% to 70% of the total mass of the second resin;

[0014] It also includes an adhesion promoter, wherein the mass of the adhesion promoter is 1% to 5% of the total mass of the second resin.

[0015] Furthermore, the base coating comprises 2 to 15 parts by weight of a third resin and 90 to 98 parts by weight of an organic solvent;

[0016] The third resin includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, etc., and the organic solvent is an aqueous solution of isopropanol.

[0017] Furthermore, the dye layer comprises 2 to 15 parts by weight of a fourth resin, 2 to 15 parts by weight of dye, and 80 to 95 parts by weight of organic solvent;

[0018] The fourth resin includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, polyurethane, polycarbonate, and polyester resin, and the organic solvent is a mixed solution of butanone and toluene.

[0019] Furthermore, the thickness of the release layer is 0.5~1.5μm, the thickness of the adhesive layer is 1~5μm, the thickness of the substrate is 4~125μm, the thickness of the base coating layer is 0.1~0.5μm, and the thickness of the dye layer is 0.5~1.5μm.

[0020] The present invention also provides a transfer method suitable for printing PET cards, which uses a sublimation ribbon as described above to print a pattern onto the re-transfer film through the dye layer to form a pattern layer; then the adhesion promoting layer is printed onto the pattern layer; finally, the re-transfer film is used to print the pattern layer and the adhesion promoting layer onto the surface of the PET card.

[0021] The present invention also provides a retransfer film for use in the above-described transfer method, the retransfer film comprising a retransfer film substrate and a dye receiving layer disposed on one side of the substrate; the dye receiving layer comprising 10 to 40 parts by weight of a fifth resin and 60 to 90 parts by weight of an organic solvent; wherein the fifth resin comprises vinyl chloride-vinyl acetate copolymer and polyurethane resin, the mass of the vinyl chloride-vinyl acetate copolymer being 60% to 90% of the total mass of the fifth resin, and the mass of the polyurethane resin being 10% to 40% of the total mass of the fifth resin.

[0022] Furthermore, the thickness of the retransfer film substrate is 4~125μm, and the thickness of the receiving layer is 5~6μm.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) The sublimation ribbon of the present invention for printing PET cards can achieve the printing process of printing the dye layer onto the transfer film and then printing the adhesion promoting layer onto the dye layer by adding an adhesion promoting layer on the base coating layer, thereby realizing the printing of PET cards;

[0025] (2) The thermal sublimation ribbon of the present invention is suitable for printing PET ID cards. The release layer can ensure adhesion during the printing process and promote the complete printing or transfer of the layer. The adhesive layer can effectively improve the adhesion of the pattern on the PET ID card, thus effectively improving the adhesion of the pattern on the PET ID card.

[0026] (3) The sublimation ribbon of the present invention, which is suitable for printing PET cards, can effectively improve the color concentration, durability, scratch resistance, solvent resistance and other properties of the pattern on the PET card;

[0027] (4) The transfer method of the present invention for printing PET ID cards transfers the pattern imaged on the re-transfer film by the thermal sublimation ribbon to the PET ID card, so that the pattern layer is located inside the coating layer, thereby further improving the abrasion resistance and solvent resistance of the pattern on the PET ID card.

[0028] (5) The re-transfer film of the present invention can be used in conjunction with the thermal sublimation ribbon of the present invention to achieve PET card printing and has a good printing effect. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the layer structure of the sublimation ribbon for PET card printing according to the present invention;

[0030] Figure 2 This is a schematic diagram of the layer structure of the retransfer film of the present invention;

[0031] Figure 3 This is a schematic diagram of the layer structure of the printed PET card, which is a printing method of the present invention.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. Back coating; 2. Substrate; 3. Primer coating; 4. Adhesion promoting layer; 41. Release layer; 42. Adhesive layer; 5. Dye layer; 6. Re-transfer film substrate; 7. Dye receiving layer; 8. PET card base layer; 9. Pattern layer. Detailed Implementation

[0034] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0035] The present invention provides a sublimation ribbon suitable for printing PET cards, comprising a substrate 2, a base coating 3 on one side of the substrate 2, and a dye layer 5 on the base coating 3; it also includes an adhesion promoting layer 4; the adhesion promoting layer 4 includes a release layer 41 and an adhesive layer 42, the release layer 41 being disposed on one side of the substrate 2, and the adhesive layer 42 being disposed on the release layer 41.

[0036] The sublimation ribbon of this invention, by adding an adhesion-promoting layer 4 to the base coating layer 3, enables the printing process of printing the pattern onto the re-transfer film via the dye layer 5, and then printing the adhesion-promoting layer 4 onto the pattern layer 9. The release layer 41 ensures the complete printing and transfer of the adhesion-promoting layer 4 during the printing process, and the subsequent layer 42 effectively improves the adhesion of the pattern to the PET card. Thus, by setting the adhesion-promoting layer 4, the printing effect of the PET card can be improved, and the color density and durability of the card's images and text can be enhanced.

[0037] Preferred, such as Figure 1 As shown, the specific layer structure of the thermal sublimation ribbon of the present invention is as follows: the release layer 41 and the base layer 3 are located on the same layer, and the dye layer 5 and the adhesive layer 42 are located on the same layer. Furthermore, the dye layer 5 includes multiple color regions, each with a different dye, and these multiple color regions are arranged sequentially.

[0038] In the thermal sublimation ribbon of the present invention, the release layer 41 includes the following components, and the mass fraction of each component is: 10-30 parts of the first resin and 70-90 parts of the first organic solvent; preferably, 15-25 parts of the first resin and 75-85 parts of the first organic solvent.

[0039] The first resin is a mixture of vinyl chloride-vinyl acetate copolymer and polyurethane, wherein the mass of vinyl chloride-vinyl acetate copolymer accounts for 70%-90% of the total mass of the first resin, preferably 80%-90%; and the mass of polyurethane accounts for 10%-30% of the total mass of the first resin, preferably 10%-20%.

[0040] The vinyl chloride-vinyl acetate copolymer ensures that the adhesion promoting layer 4 can be completely transferred from the thermal sublimation ribbon to the re-transfer film and then to the PET card, avoiding problems such as residue during the transfer process; the role of polyurethane is to slightly increase the adhesion of the release layer 41 to the substrate 2, so that it will not fall off during printing.

[0041] In the release layer 41 of the present invention, the first organic solvent used is a mixed solvent of butanone and toluene, with a mass ratio of 1:1.

[0042] Further preferably, without affecting or damaging the release effect of the release layer 41, the composition of the release layer 41 also includes functional materials. Functional materials include one or more of the following: fillers, plasticizers, antistatic materials, ultraviolet absorbing materials, inorganic microparticles, organic microparticles, release agents, and dispersants.

[0043] Preferably, the mass percentage of the functional material is 1% to 2.5% of the total mass of the first resin.

[0044] Preferably, the thickness of the release layer 41 is 0.5~1.5μm, and more preferably 0.7~1.2μm.

[0045] In the thermal sublimation ribbon of the present invention, the adhesive layer 42 comprises 20 to 40 parts by weight of a second resin and 60 to 80 parts by weight of a second organic solvent, preferably 65 to 75 parts by weight; the second organic solvent is a methyl ethyl ketone-toluene mixed solvent, and the mass ratio of the two is 1:1.

[0046] The second resin includes a thermoplastic resin and a vinyl chloride-vinyl acetate copolymer. The thermoplastic resin comprises 30% to 80% of the total mass of the second resin, more preferably 60% to 75%; the vinyl chloride-vinyl acetate copolymer comprises 20% to 70% of the total mass of the second resin, more preferably 25% to 40%. The thermoplastic resin is added to soften upon heating, thereby improving adhesion. The vinyl chloride-vinyl acetate copolymer is added to enhance the interlayer adhesion between the adhesive layer 42 and the release layer 41, and between the adhesive layer 42 and the retransfer film.

[0047] Further preferably, the thermoplastic resin is one or more of polyester, vinyl resin, (meth)acrylic resin, (meth)acrylic resin, polyurethane, cellulose resin, polyamide, polyolefin, styrene resin, and their chlorinated resins, with polyester resin being the most preferred.

[0048] To further improve the adhesion between the adhesive layer 42 and the dye layer 5 on the PET card, the preferred glass transition temperature of the polyester resin is 20°C to 90°C, more preferably 50°C to 80°C.

[0049] To further improve its adhesion to PET, a certain amount of adhesion promoter can be added, which is 1%-5% of the second resin. Preferably, the amount of adhesion promoter added is 3% to 5% of the second resin.

[0050] Preferably, the composition of the next layer 42 also includes additives such as dispersing materials and lubricants.

[0051] Preferably, the thickness of the bonding layer 42 is 1~5μm, and more preferably 2~4μm.

[0052] In the sublimation ribbon of the present invention, a back coating 1 is provided on the other side of the substrate 2. The main function of the back coating 1 is to adapt to the high-speed printing of the sublimation printer, improve the heat resistance and lubricity of the substrate 2, prevent adhesion and printing wrinkles caused by the heat of the thermal head during the printing process, and ensure the heat transfer of the print head without melting the substrate 2 under high heat printing conditions.

[0053] For the back coating 1, the material is a resin component, and the resin types that can be selected are PVB resin, cellulose resin, silicone-modified polyurethane, polyamide resin, etc.; among them, high acetal and high TG PVB resin is preferred, the molecular weight is preferably 50,000 to 60,000, and the degree of polymerization is preferably 300 to 1300.

[0054] Preferably, the resin component of the back coating 1 is 5 to 20 parts by mass, more preferably 8 to 15 parts; the solvent is a toluene-butanone mixed solvent, the mass ratio of the two is 3:1 to 2:1, and the mass part of the solvent is preferably 80 to 90 parts.

[0055] Preferably, in order to improve the lubricity of the back coating 1 and reduce frictional damage to the print head during the printing process, a certain amount of solid lubricant, such as metal soap, phosphate ester, silicone oil, mold release agent, etc., can be added to the back coating 1, and the amount added is 1% to 5% of the resin component mass; more preferably, the amount added is 3% to 5% of the resin component mass.

[0056] Preferably, to solve the problem of material accumulation in the printhead and further improve the lubricity of the back coating layer 1, a certain amount of solid fillers such as silica, talc, and kaolin can be added to the back coating layer 1. The particle size of the filler is 300 nm to 5 μm, preferably 1 to 4 μm. The added mass of the filler is 1% to 5% of the total mass of the resin component, and more preferably, the added mass of the filler is 3% to 5% of the total mass of the resin. If the particle size of the filler is too large, it will affect the surface smoothness of the back coating layer 1; if it is too small, it will not be able to reduce the friction between the printhead and the back coating layer 1.

[0057] Preferably, the thickness of the back coating 1 is 0.2~1μm, and more preferably 0.5~0.8μm.

[0058] Regarding the base coating 3, the base coating 3 of the present invention comprises 2 to 15 parts by weight of a third resin and 90 to 98 parts by weight of a third organic solvent; preferably, the third resin comprises 3 to 8 parts by weight. The third resin includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, etc., and the third organic solvent is an aqueous solution of isopropanol. The organic solvent is a mixture of water and isopropanol, with a mixing mass ratio of 2:1 to 1:1.

[0059] In the thermal sublimation ribbon of this invention, the main function of the base coating layer 3 is to improve the adhesion and dispersibility of the dye on the PET substrate, thereby improving the uniformity of the printed pattern and the vibrancy of the colors. During the printing process, when heated, the dye diffuses simultaneously in two opposite directions to the substrate and the adhesive layer. Therefore, the base coating layer 3 is preferably selected from a third resin or sol that simultaneously satisfies the requirements of poor dye adsorption and excellent adhesion to the substrate. For cost and coating effect considerations, one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, etc., are preferred.

[0060] Preferably, the thickness of the base coating 3 is 0.1~0.5μm, and more preferably 0.1~0.3μm. Too thin or too thick a base coating 3 may result in ink fading during printing.

[0061] Regarding the dye layer 5, the dye layer 5 of the present invention comprises 2 to 15 parts by weight of a fourth resin, 2 to 15 parts by weight of a dye, and 80 to 95 parts by weight of a fourth organic solvent; the fourth resin preferably comprises 3 to 8 parts by weight. The dye preferably comprises 3 to 12 parts by weight, and the fourth organic solvent preferably comprises 85 to 90 parts by weight.

[0062] In the thermal sublimation ribbon of this invention, the main function of dye layer 5 is to provide the dye for true-color printing. The fourth resin in dye layer 5 includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, polyurethane, polycarbonate, and polyester resin, etc., and its function is to have good adhesion, enabling the dye to have a good bonding effect. There are no particular limitations on the specific type of dye in dye layer 5; it can be selected from many sublimation dyes. Dyes with low melting and sublimation temperatures and good solubility are preferred.

[0063] The fourth organic solvent is a mixed solution of butanone and toluene, with a mass ratio of 1:1.

[0064] Further preferably, the thermal sublimation ribbon of the present invention uses four dyes: yellow, magenta, cyan, and black, to ensure that the color density and grayscale density of the pattern in card printing meet the desired values. To ensure that the printed colors reproduce the original image as accurately as possible, it is necessary to maintain the printing density at higher color levels while keeping the color density at lower levels relatively low. Therefore, this ribbon better reproduces lighter color levels by reducing the ratio of the CMY three-color dyes to the fourth resin, while increasing the black ribbon to compensate for the printing density at higher color levels. Preferably, the mass ratio of the CMY three-color dyes to the fourth resin is 1:1 to 1:1.4.

[0065] Preferably, to ensure the ribbon can withstand the high heat and pressure required for printing and to reduce the transfer of liquid lubricant from the substrate to the ribbon, thus preventing the ribbon from sticking to the substrate during printing, the slip properties of the dye layer 5 need to be increased. A certain amount of silicone oil can be added to the dye layer 5 to improve the slip properties of the ribbon surface. Considering that the dye layer 5 will directly contact the back coating layer 1 during ribbon winding, a non-reactive silicone oil is preferred to reduce the loss of lubricant in the dye layer 5. The amount of non-reactive silicone oil added is 0.5% to 1.5% of the total mass of the fourth resin.

[0066] In addition, to ensure that the sublimation ribbon maintains good printing quality after exposure to high temperature and humidity environments and prevents the dye layer from sticking to the back coating layer, a certain amount of solid lubricant can be added to the dye layer 5. Preferably, the solid lubricant is polymethyl methacrylate (PMMA), which has advantages such as high mechanical strength, good light transmittance, and low cost. The amount of solid lubricant added is 0.5% to 1.5% of the total mass of the fourth resin. The amount of solid lubricant added needs to be carefully controlled. If too much is added, the printing color density will decrease; if too little is added, the back coating layer 1 may stick to the dye layer 5.

[0067] Preferably, the thickness of the dye layer 5 is 0.5~1.5μm, and more preferably 0.7~1.2μm.

[0068] like Figure 2 As shown, the retransfer film of the present invention includes a retransfer film substrate 6 and a dye receiving layer 7 disposed on one side of the retransfer film substrate 6.

[0069] The primary function of the retransfer film substrate 6 is to support the dye receiving layer 7. Common retransfer film substrates 6 are plastic films such as polyethylene terephthalate (PET), polypropylene (PP), or polyethylene (PE), or paper such as synthetic paper, coated paper, processed printing paper, casting paper, or non-wood paper. It needs to have sufficient heat resistance to withstand the heat from the heating head and sufficient rigidity to prevent cracking during processing. Preferably, the retransfer film substrate 6 is a polyethylene terephthalate film.

[0070] Preferably, the thickness of the retransfer film substrate 6 is 4~125μm, and more preferably, the thickness is 12~50μm.

[0071] The dye receiving layer 7 is used to receive the dye transferred during the printing process. Its main components are a fifth resin and a fifth organic solvent. The mass fraction of the fifth resin is 10 to 40 parts, preferably 15 to 25 parts. The fifth organic solvent is a methyl ethyl ketone-toluene mixed solvent with a mass ratio of 1:1. The mass fraction of the fifth organic solvent is 60 to 90 parts, preferably 75 to 85 parts.

[0072] The fifth resin comprises vinyl chloride-vinyl acetate copolymer and polyurethane resin, wherein the mass of the vinyl chloride-vinyl acetate copolymer is 60% to 90% of the total mass of the fifth resin, more preferably 80% to 85%; and the mass of the polyurethane resin is 10% to 40% of the total mass of the fifth resin, more preferably 15% to 20%.

[0073] Vinyl chloride-vinyl acetate copolymer can give dye receiving layer 7 good dye receiving ability; however, vinyl chloride-vinyl acetate copolymer has poor adhesion to the retransfer film substrate 6. Therefore, adding polyurethane resin to dye receiving layer 7 can prevent dye receiving layer 7 from sticking to the thermal sublimation ribbon during image printing. However, if the amount of polyurethane resin added is too high, it will cause the transfer process to fail in the subsequent transfer process, and if the amount added is too low, it will not meet the requirements.

[0074] To prevent the dye receiving layer 7 from sticking to the re-transfer film substrate 6 under high temperature and humidity after winding, a certain amount of solid lubricant can be added to the dye receiving layer 7. PE wax or sol is preferred, with silica sol and alumina sol being the main types of sols. The amount of solid lubricant added is preferably 0.5% to 1.5% of the mass of the fifth resin.

[0075] In addition, adding a certain amount of anti-hydrolysis agent to the dye receiving layer 7 can ensure that the polyurethane will not absorb water and shrink; preferably, the amount of anti-hydrolysis agent added is 1% to 3% of the total mass of the fifth resin.

[0076] The transfer method of the present invention for printing PET cards uses the aforementioned sublimation ribbon to print the dye layer 5 onto a re-transfer film, forming a pattern layer 9; then, an adhesion promoting layer 4 is printed onto the pattern layer 9; finally, the re-transfer film is used to print the pattern layer 9 and the adhesion promoting layer 4 onto the surface of the PET card. The layer structure of the printed PET card is as follows: Figure 3 As shown, the PET card base layer 8 has an adhesion promoting layer 4, and the adhesion promoting layer 4 has a pattern layer 9.

[0077] Specifically, the following steps are included:

[0078] First, using the sublimation ribbon of this invention, a mirror image of the desired pattern is printed onto the dye receiving layer 7 of the retransfer film using a Hunan Dingyi Zhiyuan DT-330A sublimation label printing machine. Specifically, the dye concentration is controlled by adjusting the printhead temperature, and the CMYK four-color dyes in the dye layer of the sublimation ribbon are overlaid and printed onto the dye receiving layer 7 of the retransfer film to obtain a retransfer film with a pattern layer 9.

[0079] Next, the adhesion promoting layer 4 is printed on top of the pattern layer 9 to obtain a re-transfer film with the pattern layer 9 and the adhesion promoting layer 4.

[0080] Finally, the pattern layer 9 and adhesion promoting layer 4 are transferred onto the PET card using a Dessert DS-5400H card printer via a re-transfer film.

[0081] The above process can be called thermal lamination. Through this process, the pattern on the thermal sublimation ribbon is printed onto the card using a re-transfer film, which enables the thermal sublimation image to have high color density and high weather resistance in card printing applications.

[0082] The present invention will be illustrated by specific embodiments below:

[0083] Example 1 of Dye Sublimation Ribbon

[0084] This embodiment provides a sublimation ribbon.

[0085] The substrate 2 of this dye-sublimation ribbon uses a 4.3μm thick PET film manufactured by Anhui Tongai.

[0086] The composition and mass fractions of the base coating 3 are as follows: 2 parts polyvinylpyrrolidone (industrial grade PVP K90, Guangdong Yuemei Chemical), 1 part polyvinyl alcohol (Tianjin Damao Chemical), 1 part silica sol (HS830, Guangdong Huierte Nanotechnology), 48 parts water, and 48 parts isopropanol. The base coating 3 is applied using a gravure coating machine, with a coating thickness of 0.2 μm.

[0087] The composition and mass fractions of dye layer 5 are as follows: Yellow: Polyurethane (901H Wanhua Chemical) 4.5 parts, Solvent Yellow 2 (Henan Wokas Biotechnology) 4.5 parts, Polymethyl methacrylate 0.02 parts, 2-Butanone 45 parts, Toluene 45 parts; Magenta: Polyurethane (901H Wanhua Chemical) 4.5 parts, Solvent Red 24 (Sinopharm Chemical Reagent) 4.5 parts, Polymethyl methacrylate 0.03 parts, 2-Butanone 45 parts, Toluene 45 parts; Cyan: Polyurethane (901H Wanhua Chemical) 4.5 parts, Solvent Blue 36 (Nanjing Kangmanlin Chemical Industry) 4.5 parts, Polymethyl methacrylate 0.05 parts, 2-Butanone 45 parts, Toluene 45 parts; Black: Polyurethane (901H Wanhua Chemical) 4.5 parts, Dye Black 2B (Lanxess, Germany) 4.5 parts, polymethyl methacrylate 0.05 parts, 2-butanone 45 parts, toluene 45 parts. The dye layer 5 was coated using a gravure coating machine, with a coating thickness of 1.0 μm.

[0088] The composition and mass fraction of back coating 1 are as follows: 3 parts polyvinyl butyral (B265H-B Guangzhou Hongshang), 7 parts cellulose acetate butyrate (CAB393-3 Eastman Chemical, USA), 5 parts isocyanate (WANNATE® MDI-50 Wanhua Chemical), 0.3 parts glyceryl phosphate (Guangzhou Jiatu Technology), 0.3 parts zinc stearate (Henan Xinzhiyuan Chemical), 0.3 parts talc (LJ-320 Liangjiang Chemical), 0.5 parts polyethylene wax (3405G Honeywell), 0.2 parts silicone oil (KF-6001 Shin-Etsu Silicone), 58 parts 2-butanone, and 25.4 parts toluene. Back coating 1 is applied using a gravure coating machine to a thickness of 0.6 μm.

[0089] The composition and mass fractions of release layer 41 are as follows: 4 parts polyurethane (901H Wanhua Chemical), 16 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 40 parts 2-butanone, and 40 parts toluene. Release layer 41 is coated using a gravure coating machine with a coating thickness of 0.8 μm.

[0090] The composition and mass fractions of the next layer 42 are as follows: 15 parts polyester resin (VYLON220, Toyobo, Japan), 15 parts vinyl chloride-vinyl acetate copolymer (SOLBIN-C, Nissin Chemical), 1 part adhesion promoter (LTH, DIGIC, Germany), 0.35 parts PE wax (3405G, Honeywell), 0.35 parts dispersant (BYK163, BYK Chemical), 0.035 parts silicone oil (KF393, Shin-Etsu Silicone), 35 parts 2-butanone, and 35 parts toluene. The next layer 42 is coated using a gravure coating machine to a thickness of 3.0 μm.

[0091] Example 2 of Dye Sublimation Ribbon

[0092] This embodiment provides a sublimation ribbon.

[0093] The substrate 2, base coating 3, back coating 1, and dye layer 5 of this sublimation ribbon are the same as those of the sublimation ribbon in Example 1. The formulations of the release layer 41 and the adhesive layer 42 are as follows:

[0094] The composition and mass fractions of release layer 41 are as follows: 4 parts polyurethane (901H Wanhua Chemical), 16 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 40 parts 2-butanone, and 40 parts toluene. Release layer 41 is coated using a gravure coating machine, with a coating thickness of 1.2 μm.

[0095] The composition and mass fractions of the next layer 42 are as follows: 17 parts polyester resin (VYLON220, Toyobo, Japan), 17 parts vinyl chloride-vinyl acetate copolymer (SOLBIN-C, Nissin Chemical), 1 part adhesion promoter (LTH, DIGIC, Germany), 0.35 parts PE wax (3405G, Honeywell), 0.35 parts dispersant (BYK163, BYK Chemical), 0.035 parts silicone oil (KF393, Shin-Etsu Silicone), 32 parts 2-butanone, and 32 parts toluene. The next layer 42 is coated using a gravure coating machine to a thickness of 3.0 μm.

[0096] Example 3 of Dye Sublimation Ribbon

[0097] This embodiment provides a sublimation ribbon.

[0098] The substrate 2, base coating 3, back coating 1, and dye layer 5 of this sublimation ribbon are the same as in Example 1. The formulations of the release layer 41 and adhesive layer 42 are as follows:

[0099] The composition and mass fractions of release layer 41 are as follows: 2 parts polyurethane (901H Wanhua Chemical), 18 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 40 parts 2-butanone, and 40 parts toluene. Release layer 41 is coated using a gravure coating machine with a coating thickness of 0.8 μm.

[0100] The composition and mass fractions of the next layer 42 are as follows: 20 parts polyester resin (VYLON220, Toyobo, Japan), 10 parts vinyl chloride-vinyl acetate copolymer (SOLBIN-C, Nissin Chemical), 1 part adhesion promoter (LTH, DIGIC, Germany), 0.35 parts PE wax (3405G, Honeywell), 0.35 parts dispersant (BYK163, BYK Chemical), 0.035 parts silicone oil (KF393, Shin-Etsu Silicone), 34 parts 2-butanone, and 34 parts toluene. The next layer 42 is applied using a gravure coating machine to a thickness of 3.0 μm.

[0101] Example 4 of Dye Sublimation Ribbon

[0102] This embodiment provides a sublimation ribbon.

[0103] The substrate 2, base coating 3, back coating 1, dye layer 5, and adhesive layer 42 of the sublimation ribbon are the same as in Example 1, and the release layer 41 formulation is the same as in Example 3.

[0104] Example 5 of Dye Sublimation Ribbon

[0105] This embodiment provides a sublimation ribbon.

[0106] The substrate 2, base coating 3, back coating 1, dye layer 5, and release layer 41 of the sublimation ribbon are the same as in Example 1, and the adhesive layer 42 is the same as in Example 2.

[0107] Example 6 of Dye Sublimation Ribbon

[0108] This embodiment provides a sublimation ribbon.

[0109] The substrate 2, base coating 3, back coating 1, and dye layer 5 of the sublimation ribbon are the same as in Example 1, the release layer 41 is the same as in Example 2, and the formulation of the adhesive layer 42 is the same as in Example 3.

[0110] Comparative Example 1 of Dye Sublimation Ribbons

[0111] This comparative example provides a sublimation ribbon, whose substrate 2, base coating 3, back coating 1, release layer 41, and dye layer 5 are the same as in Example 1. The formulation of the adhesive layer 42 is as follows:

[0112] The composition and mass fractions of the next layer 42 are as follows: 10 parts polyester resin (VYLON220, Toyobo, Japan), 10 parts vinyl chloride-vinyl acetate copolymer (SOLBIN-C, Nissin Chemical), 1 part adhesion promoter (LTH, DIGIC, Germany), 0.35 parts PE wax (3405G, Honeywell), 0.35 parts dispersant (BYK163, BYK Chemical), 0.035 parts silicone oil (KF393, Shin-Etsu Silicone), 40 parts 2-butanone, and 40 parts toluene. The next layer 42 is coated using a gravure coating machine to a thickness of 3.0 μm.

[0113] Comparison Example 2: Sublimation ribbon

[0114] This comparative example provides a sublimation ribbon, with the substrate 2, base coating 3, back coating 1, release layer 41, and dye layer 5 being identical to those in Comparative Example 2. The formulation of the adhesive layer 42 is as follows:

[0115] The composition and mass fractions of the next layer 42 are as follows: 10 parts polyester resin (VYLON220, Toyobo, Japan), 20 parts vinyl chloride-vinyl acetate copolymer (SOLBIN-C, Nissin Chemical), 1 part adhesion promoter (LTH, DIGIC, Germany), 0.35 parts PE wax (3405G, Honeywell), 0.35 parts dispersant (BYK163, BYK Chemical), 0.035 parts silicone oil (KF393, Shin-Etsu Silicone), 35 parts 2-butanone, and 35 parts toluene. The next layer 42 is applied using a gravure coating machine to a thickness of 3.0 μm.

[0116] Comparison of Dye Sublimation Ribbons 3:

[0117] Each coating formulation is consistent with Example 1, but without the adhesion promoting layer 4.

[0118] Comparison of Dye Sublimation Ribbons 4:

[0119] Substrate 2, primer 3, back coating 1, adhesive layer 42, and dye layer 5 are the same as in Comparative Example 1. The composition and mass fraction of release layer 41 are as follows: 8 parts polyurethane (901H Wanhua Chemical), 12 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 40 parts 2-butanone, and 40 parts toluene. Release layer 41 is coated using a gravure coating machine with a coating thickness of 0.8 μm.

[0120] Example 1 of re-transfer film coating:

[0121] This embodiment provides a retransfer film, wherein the retransfer film substrate 6 is a 50μm thick PET film manufactured by Dongguan Shunming Electronic Materials.

[0122] The composition and mass fractions of dye receiver layer 7 are as follows: 2 parts polyurethane (905H Wanhua Chemical), 18 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 0.2 parts PE wax (3405G Honeywell), 0.4 parts polymerized carbodiimide (AS4 Lai'an Industrial), 40 parts 2-butanone, and 40 parts toluene. Dye receiver layer 7 is coated using a gravure coating machine to a thickness of 5 μm.

[0123] Example 2 of re-transfer film coating:

[0124] This embodiment provides a retransfer film, wherein the retransfer film substrate 6 is a 50μm thick PET film manufactured by Dongguan Shunming Electronic Materials.

[0125] The composition and mass fractions of dye receiver layer 7 are as follows: 4 parts polyurethane (905H Wanhua Chemical), 16 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 0.2 parts PE wax (3405G Honeywell), 0.4 parts polymerized carbodiimide (AS4 Lai'an Industrial), 40 parts 2-butanone, and 40 parts toluene. Dye receiver layer 7 is coated using a gravure coating machine to a thickness of 5 μm.

[0126] Example 3 of re-transfer film coating:

[0127] This embodiment provides a retransfer film, wherein the retransfer film substrate 6 is a 50μm thick PET film manufactured by Dongguan Shunming Electronic Materials.

[0128] The composition and mass fractions of dye receiver layer 7 are as follows: 2 parts polyurethane (905H Wanhua Chemical), 18 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 0.15 parts PE wax (3405G Honeywell), 0.3 parts polymerized carbodiimide (AS4 Lai'an Industrial), 40 parts 2-butanone, and 40 parts toluene. Dye receiver layer 7 is coated using a gravure coating machine to a thickness of 5 μm.

[0129] Example 4 of re-transfer film coating:

[0130] This embodiment provides a retransfer film, whose retransfer film substrate 6 and dye receiving layer 7 are the same as those in the retransfer film coating embodiment 1, but the coating thickness of the dye receiving layer 7 is 6μm.

[0131] Comparative Example 1: Re-transfer film coating

[0132] This comparative example provides a retransfer film, whose retransfer film substrate 6 and dye receiving layer 7 are the same as those in Example 1, but the coating thickness of the dye receiving layer 7 is 3 μm.

[0133] Comparative Example 2: Re-transfer film coating

[0134] This comparative example provides a retransfer film, wherein the retransfer film substrate 6 is a 50μm thick PET film manufactured by Dongguan Shunming Electronic Materials.

[0135] The dye receiving layer 7 comprises the following components and parts by weight: 20 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 0.2 parts PE wax (3405G Honeywell), 0.4 parts polymerized carbodiimide (AS4 Lai'an Industrial), 45 parts 2-butanone, and 45 parts toluene. The dye receiving layer 7 is coated using a gravure coating machine to a thickness of 5 μm.

[0136] Comparative Example 3: Re-transfer film coating

[0137] This comparative example provides a retransfer film, wherein the retransfer film substrate 6 is a 50μm thick PET film manufactured by Dongguan Shunming Electronic Materials.

[0138] The composition and mass fractions of dye receiver layer 7 are as follows: 10 parts polyurethane (905H Wanhua Chemical), 10 parts vinyl chloride-vinyl acetate copolymer (CP450 Hanwha), 0.2 parts PE wax (3405G Honeywell), 0.4 parts polymerized carbodiimide (AS4 Lai'an Industrial), 45 parts 2-butanone, and 45 parts toluene. Dye receiver layer 7 is coated using a gravure coating machine to a thickness of 5 μm.

[0139] The following tests were conducted on the PET card patterns printed using the above embodiments and comparative examples: The performance test plan involved using a Hunan Dingyi Yiyuan DT-330A dye-sublimation soft label printer at a printing speed of 6 m / min. The test pattern was a 255 grayscale image. The printing ribbons were the YMC three-color ribbons used in examples 1-6 and comparative examples 1-4. The printing substrates were the re-transfer film coating examples 1-4 and the substrate coating comparative examples 1-3. The re-transfer film was transferred using a Deshi DS-5400H card printer, with the printing substrate being a PET card.

[0140] The following performance tests were performed on the final transferred PET card image:

[0141] (1) Adhesion test:

[0142] Adhesion testing was conducted using a BYK cross-cut adhesion tester (Germany). The test level was based on the ISO 2409 cross-cut adhesion test standard, as shown below:

[0143] 0: The cut edges are completely smooth; not a single grid has fallen off.

[0144] 1. A small amount of coating has peeled off at the intersection of the cuts. The affected area of ​​the cross-cut should not exceed 5%.

[0145] 2: Coating peeling is present at the cut edges and / or intersections. The affected cut area is greater than 5% but less than 15%.

[0146] 3: The coating peels off in large fragments, partially or completely, along the cut edge, and / or partially or completely at different locations within the grid. The affected cut area is greater than 15% but less than 35%.

[0147] 4: Large fragments of coating have peeled off along the cut edge, and / or some grid areas have partially or completely peeled off. The affected cut area is greater than 35% but less than 65%.

[0148] 5: Any degree of shedding beyond level 4.

[0149] The adhesion test results are shown in Table 1:

[0150] Table 1

[0151]

[0152] (2) Transfer effect test: The color density of the final transfer maximum grayscale result was tested using an X-Rite i1-PRO3 colorimeter.

[0153] The color density test results are shown in Table 2:

[0154] Table 2

[0155]

[0156] (3) Solvent resistance test: A 1.0KGF mold was tied to the bottom with white cotton gauze, soaked in 95% alcohol, and then the white cotton gauze was used to rub back and forth 300 times on the printed pattern. The optical density before and after solvent rubbing was tested using an X-Rite i1-PRO3 colorimeter, and the ratio of optical density after the test to optical density before the test was calculated. The judgment criteria are as follows:

[0157] √: Optical density after test / optical density before test ≥ 0.8;

[0158] ×: Optical density after test / optical density before test < 0.8.

[0159] The solvent resistance test results are shown in Table 3:

[0160] Table 3

[0161]

[0162] (4) Scratch Resistance Test: The abrasion resistance of the samples was tested using the MCJ-01A friction testing machine independently developed and manufactured by Jinan Langguang Electromechanical Technology Co., Ltd. The friction pressure was 20±0.2N, the friction speed was 43 times / min, and the number of friction cycles was 40. The abrasion resistance of the samples was judged visually, and the judgment criteria are as follows:

[0163] √: The ink layer on the printing surface has no exposed ink (color fading) or no staining on the paper surface when rubbed;

[0164] ×: The ink layer on the printing surface shows through (color loss) or there is staining on the paper surface when rubbed.

[0165] The results of the scratch resistance test are shown in Table 4:

[0166] Table 4

[0167]

[0168] The test results show that the sublimation ribbon and re-transfer film not only have a color density close to that of DNP original photo paper, but also have good adhesion, solvent resistance and abrasion resistance after transfer.

[0169] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sublimation ribbon suitable for printing PET cards, comprising a substrate (2), wherein a base coating (3) is provided on one side of the substrate (2), and a dye layer (5) is provided on the base coating (3); characterized in that, It also includes an adhesion promoting layer (4); the adhesion promoting layer (4) includes a release layer (41) and an adhesive layer (42), the release layer (41) is disposed on one side of the substrate (2), and the adhesive layer (42) is disposed on the release layer (41); The release layer (41) includes the following components, and the mass fraction of each component is: 10-30 parts of the first resin and 70-90 parts of the first organic solvent; The first resin is a mixture of vinyl chloride-vinyl acetate copolymer and polyurethane, wherein the mass of vinyl chloride-vinyl acetate copolymer accounts for 70% to 90% of the total mass of the first resin, and the mass of polyurethane accounts for 10% to 30% of the total mass of the first resin; The adhesive layer (42) comprises 20 to 40 parts by weight of a second resin and 60 to 80 parts by weight of a second organic solvent; The second resin comprises a thermoplastic resin and a vinyl chloride-vinyl acetate copolymer, wherein the thermoplastic resin accounts for 30% to 80% of the total mass of the second resin, and the vinyl chloride-vinyl acetate copolymer accounts for 20% to 70% of the total mass of the second resin; The thermoplastic resin is a polyester resin, and the glass transition temperature of the polyester resin is above 20°C and below 90°C.

2. The sublimation ribbon for PET card printing according to claim 1, characterized in that, The release layer (41) further includes functional materials, the mass percentage of which is 1% to 2.5% of the total mass of the first resin; the functional materials include one or more of the following: filler materials, plasticizers, antistatic materials, ultraviolet absorbing materials, inorganic microparticles, organic microparticles, release materials, and dispersion materials.

3. The sublimation ribbon for PET card printing according to claim 1, characterized in that, The adhesive layer (42) further includes an adhesion promoter, wherein the mass of the adhesion promoter is 1%-5% of the total mass of the second resin.

4. A sublimation ribbon suitable for PET card printing according to any one of claims 1 to 3, characterized in that, The base coating (3) comprises 2 to 15 parts by weight of a third resin and 90 to 98 parts by weight of an organic solvent; The third resin includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, and methylcellulose, and the organic solvent is an aqueous solution of isopropanol.

5. A sublimation ribbon suitable for PET card printing according to any one of claims 1 to 3, characterized in that, The dye layer (5) comprises 2 to 15 parts by weight of a fourth resin, 2 to 15 parts by weight of dye, and 80 to 95 parts by weight of organic solvent; The fourth resin includes one or more of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, methylcellulose, polyurethane, polycarbonate, and polyester resin, and the organic solvent is a mixed solution of butanone and toluene.

6. A sublimation ribbon suitable for PET card printing according to any one of claims 1 to 3, characterized in that, The thickness of the release layer (41) is 0.5~1.5μm, the thickness of the adhesive layer (42) is 1~5μm, the thickness of the substrate (2) is 4~125μm, the thickness of the base layer (3) is 0.1~0.5μm, and the thickness of the dye layer (5) is 0.5~1.5μm.

7. A transfer method suitable for printing PET ID cards, characterized in that, Using the sublimation ribbon as described in any one of claims 1 to 6, the pattern is printed onto the retransfer film through the dye layer (5) to form a pattern layer (9); then the adhesion promoting layer (4) is printed onto the pattern layer (9), and finally the retransfer film is used to print the pattern layer (9) and the adhesion promoting layer (4) onto the surface of the PET card.

8. A re-transfer film for use in the transfer method of claim 7, characterized in that, The retransfer film includes a retransfer film substrate (6) and a dye receiving layer (7) disposed on one side of the retransfer film substrate (6); the dye receiving layer (7) includes 10 to 40 parts by weight of a fifth resin and 60 to 90 parts by weight of an organic solvent; wherein the fifth resin includes vinyl chloride-vinyl acetate copolymer and polyurethane resin, the mass of the vinyl chloride-vinyl acetate copolymer is 60% to 90% of the total mass of the fifth resin, and the mass of the polyurethane resin is 10% to 40% of the total mass of the fifth resin.

9. The retransfer film according to claim 8, characterized in that, The thickness of the retransfer film substrate (6) is 4~125μm, and the thickness of the receiving layer (7) is 5~6μm.

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