Pyrography film capable of being efficiently stripped and preparation process thereof

Abstract

The invention discloses a pyrograph film capable of being efficiently stripped. The pyrograph film capable of being efficiently stripped comprises a base material layer, a release layer, a transfer layer and a hot melt adhesive layer which are sequentially stacked, the transfer layer comprises a pattern layer and a dielectric enhancement layer, the pattern layer and the dielectric enhancement layer are sequentially stacked, the pattern layer is arranged towards one side of the release layer, and the dielectric enhancement layer is arranged towards one side of the hot melt adhesive layer; the dielectric enhancement layer is of a layer structure with the thickness of 3 + / -0.3 [mu] m, and the layer structure is prepared from, by mass, 60% of acrylic resin, 30% of aluminum oxide nanowires and 10% of flatting agent. According to the pyrograph film capable of being stripped efficiently, the dielectric constant between the pattern layer and the hot melt adhesive layer is effectively increased through the dielectric enhancement layer, so that the overall material polarization capability and electrostatic adsorption capacity of the transfer layer are remarkably enhanced, and the problem of edge diffusion of ink in the transfer printing process of the pattern layer is solved; the adhesive force of the transfer layer to application environments such as curved surfaces and porous materials is improved, and the transfer precision and durability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat transfer films, and particularly to a heat transfer film that can be efficiently peeled off. Background Art

[0002] A heat transfer film is a functional material that transfers patterns to the surfaces of substrates such as fabrics, plastics, and metals through a hot pressing process. Its core technology is based on the combination of the adhesive properties of hot melt adhesives and printing processes, and is widely used in the fields of clothing, packaging, advertising, and home decoration. Existing heat transfer films generally consist of a substrate layer, a release layer, a pattern layer, and a hot melt adhesive layer; among them, the substrate layer is usually a PET film, providing mechanical strength and high temperature resistance; the release layer is usually a silicone oil coating for easy pattern peeling; the pattern layer is usually screen printing or digital printing ink to carry pattern information; the hot melt adhesive layer is usually EVA or PUR glue for bonding.

[0003] However, the existing heat transfer films have insufficient peeling performance and pattern accuracy, resulting in unstable transfer processing accuracy and quality, and a high defective product rate in actual applications. Summary of the Invention

[0004] Based on this, in view of the technical problems of insufficient peeling performance and pattern accuracy of existing heat transfer films, it is necessary to provide a heat transfer film that can be efficiently peeled off.

[0005] A heat transfer film that can be efficiently peeled off, which includes a substrate layer, a release layer, a transfer layer, and a hot melt adhesive layer stacked in sequence, that is, the release layer is disposed on one surface of the substrate layer; the transfer layer is disposed on the surface of the release layer facing away from the substrate layer; the hot melt adhesive layer is disposed on the surface of the transfer layer facing away from the release layer, thereby forming the main structure of the heat transfer film.

[0006] The transfer layer includes a pattern layer and a dielectric enhancement layer, and the pattern layer and the dielectric enhancement layer are stacked in sequence, wherein the pattern layer is disposed on the side facing the release layer, and the dielectric enhancement layer is disposed on the side facing the hot melt adhesive layer.

[0007] The dielectric enhancement layer is set to be a layer structure with a thickness of 3 ± 0.3 μm made of 60% acrylic resin, 30% alumina nanowires, and 10% leveling agent by mass ratio.

[0008] In one embodiment, the above-mentioned substrate layer is made of a biaxially oriented polyester film (BOPET) with a thickness of 75 ± 2 μm.

[0009] In one embodiment, the above-mentioned release layer is formed by coating a nano-composite silicone resin on the surface of the substrate layer to form a nano-porous layer structure with a thickness of 10 ± 1 μm.

[0010] In one embodiment, the above-mentioned pattern layer is coated on the surface of the release layer with UV-curable pigment ink to form a layer structure with a thickness of 5 ± 0.5 μm.

[0011] In one embodiment, the above-mentioned hot melt adhesive layer is coated on the surface of the dielectric enhancement layer with a polyester-PU-EVA ternary blend system to form a layer structure with a thickness of 25 ± 2 μm.

[0012] A heat transfer film preparation process, which is used to prepare the above-mentioned heat transfer film that can be efficiently peeled off, and includes the following steps: S1. Plasma-treat BOPET with argon to increase the surface energy of the substrate and enhance the adhesion of the release layer; then use an electrostatic dust removal roller combined with a high-voltage ion air knife to perform warning dust removal treatment on BOPET to obtain a substrate layer; S2. Coating the surface of the substrate layer with nano-composite silicone resin by microgravure printing, and then curing by UV for 3 s and infrared post-curing for 30 s to obtain a release layer; S3. Spraying UV-curable pigment ink onto the surface of the release layer by an inkjet system, and then curing by UV for 2 s to obtain a pattern layer; S4. Coating a mixture of acrylic resin, alumina nanowires and leveling agent mixed in a preset ratio on the surface of the pattern layer by slit extrusion coating, and then curing by electron beam radiation to obtain a dielectric enhancement layer; S5. Coating the polyester-PU-EVA ternary blend system on the surface of the dielectric enhancement layer by hot melt spraying, and then cooling and shaping for 10 s by a cooling roller to obtain a hot melt adhesive layer.

[0013] In one embodiment, the argon flow rate in step S1 above is set to 15 L / min, the power is set to 2.5 kW, and the processing speed is set to 15 m / min; the cleanliness of the production area is controlled to Class 100.

[0014] In one embodiment, the microgravure printing in step S2 above uses a 200-mesh anilox roll with a coating amount of 12 g / m 2 ; the coating speed is set to 25 m / min; UV curing uses a mercury lamp with an intensity set to 120 mW / cm 2 , and the wavelength is set to 254 nm; the infrared post-curing temperature is set to 80 °C.

[0015] In one embodiment, the ink in step S3 above is cured by UV-LED, the wavelength is set to 385 nm, and the intensity is set to 1000 mW / cm 2 ; the inkjet system uses a Ricoh MH5420 piezoelectric print head, and the ink uses Huntsman UV-curable pigment ink.

[0016] In one embodiment, the coating temperature in step S4 above is set to 120 °C, and the thickness is controlled by an on-line β-ray thickness gauge; the temperature of the cooling roll is set to 15 °C.

[0017] The above-mentioned heat transfer film that can be efficiently peeled off effectively improves the dielectric constant between the pattern layer and the hot melt adhesive layer through the dielectric enhancement layer, thereby significantly enhancing the overall material polarization ability and electrostatic adsorption force of the transfer layer, and further reducing the problem of ink edge diffusion in the pattern layer during the transfer process, so that the adhesion of the transfer layer to application environments such as curved surfaces and porous materials is improved, and the transfer accuracy and durability are enhanced. Specifically, the heat transfer film can achieve thermal-triggered peeling through the release layer with a nano-porous layer structure, effectively ensuring the high efficiency of peeling of the heat transfer film, and the hot melt adhesive layer supported by the ternary blend system can keep the hot melt adhesive layer flexible in a low-temperature environment, while the dielectric enhancement layer added with alumina nanowires can effectively strengthen the wear resistance of the heat transfer film, thereby effectively optimizing the mechanical properties of the heat transfer film. At the same time, combined with piezoelectric inkjet in the prior art, the heat transfer film of the present invention can more effectively adsorb ink through the dielectric enhancement layer, improving the pattern accuracy and the integrity of the transfer. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a heat transfer film that can be efficiently peeled off in one embodiment. Detailed Embodiments

[0019] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is made in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0022] In the present invention, unless otherwise clearly defined and limited, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0024] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0025] Please refer to Figure 1, the present invention discloses a heat transfer film that can be efficiently peeled off. The heat transfer film that can be efficiently peeled off includes a substrate layer 100, a release layer 200, a transfer layer 300, and a hot melt adhesive layer 400 that are sequentially stacked. That is, the release layer 200 is disposed on one surface of the substrate layer 100; the transfer layer 300 is disposed on the surface of the release layer 200 facing away from the substrate layer 100; the hot melt adhesive layer 400 is disposed on the surface of the transfer layer 300 facing away from the release layer 200, thereby forming the main structure of the heat transfer film. Specifically, the transfer layer 300 includes a pattern layer 310 and a dielectric enhancement layer 320. The pattern layer 310 and the dielectric enhancement layer 320 are sequentially stacked. Among them, the pattern layer 310 is disposed on the side facing the release layer 200, and the dielectric enhancement layer 320 is disposed on the side facing the hot melt adhesive layer 400. Based on this, the dielectric enhancement layer 320 can effectively increase the dielectric constant between the pattern layer 310 and the hot melt adhesive layer 400, thereby significantly enhancing the overall material polarization ability and electrostatic adsorption force of the transfer layer 300, and further reducing the problem of ink edge diffusion of the pattern layer 310 during the transfer process, so that the adhesion of the transfer layer 300 to application environments such as curved surfaces and porous materials is improved, and the transfer accuracy and durability are increased. More specifically, the dielectric enhancement layer 320 is set to be a layer structure with a thickness of 3 ± 0.3 μm made of 60% acrylic resin, 30% alumina nanowires, and 10% leveling agent by mass. Based on this, the alumina nanowires can effectively increase the dielectric constant of the film structure. At the same time, the alumina nanowires can enhance the mechanical properties and thermal conductivity of the acrylic resin, and further improve the durability of the heat transfer film, as well as the accuracy and efficiency of pattern peeling.

[0026] Furthermore, the substrate layer 100 is made of a biaxially oriented polyester film (BOPET) with a thickness of 75 ± 2 μm.

[0027] Furthermore, the release layer 200 is formed by coating a nano-composite silicone resin on the surface of the substrate layer 100 to form a nano-porous layer structure with a thickness of 10 ± 1 μm.

[0028] Furthermore, the pattern layer 310 is formed by coating UV-curable pigment ink on the surface of the release layer 200 to form a layer structure with a thickness of 5 ± 0.5 μm.

[0029] Furthermore, the hot melt adhesive layer 400 is formed by coating a polyester-PU-EVA ternary blend system on the surface of the dielectric enhancement layer 320 to form a layer structure with a thickness of 25 ± 2 μm.

[0030] The present invention also discloses a preparation process of a heat transfer film. The preparation process of the heat transfer film is used to prepare the above-mentioned heat transfer film that can be efficiently peeled off, and it includes the following steps: S1. Argon is used to perform plasma treatment on BOPET to increase the surface energy of the substrate and enhance the adhesion of the release layer 200. Subsequently, an electrostatic dust removal roller combined with a high-voltage ion air knife is used to perform warning dust removal treatment on BOPET to obtain the substrate layer 100. S2. The nano-composite silicone resin is coated on the surface of the substrate layer 100 by microgravure printing. Subsequently, after UV curing for 3 s and infrared post-curing for 30 s, the release layer 200 is obtained. S3. The UV-curable pigment ink is inkjet-printed on the surface of the release layer 200 by an inkjet system. Subsequently, after UV curing for 2 s, the pattern layer 310 is obtained. S4. The mixture of acrylic resin, alumina nanowires, and leveling agent mixed in a preset ratio is coated on the surface of the pattern layer 310 by slit extrusion coating. Subsequently, electron beam radiation curing is performed to obtain the dielectric enhancement layer 320. S5. The polyester-PU-EVA ternary blend system is coated on the surface of the dielectric enhancement layer 320 by hot melt spraying. Subsequently, it is cooled and shaped by a cooling roller for 10 s to obtain the hot melt adhesive layer 400.

[0031] In one embodiment, the argon flow rate in step S1 above is set to 15 L / min, the power is set to 2.5 kW, and the processing speed is set to 15 m / min; the cleanliness of the production area is controlled to Class 100.

[0032] In one embodiment, the microgravure printing in step S2 above uses a 200-mesh anilox roll with a coating amount of 12 g / m 2 ; the coating speed is set to 25 m / min; the UV curing uses a mercury lamp with an intensity of 120 mW / cm 2 , the wavelength is set to 254 nm; the infrared post-curing temperature is set to 80 °C.

[0033] In one embodiment, the ink in step S3 above is cured by UV-LED with a wavelength set to 385 nm and an intensity set to 1000 mW / cm 2 ; the inkjet system uses a Ricoh MH5420 piezoelectric printhead, and the ink uses Huntsman UV-curable pigment ink.

[0034] In one embodiment, the coating temperature in step S4 above is set to 120 °C, and the thickness is controlled by an on-line β-ray thickness gauge; the temperature of the cooling roller is set to 15 °C.

[0035] The preparation process of the heat transfer film disclosed in the present invention strengthens product properties such as the peeling efficiency, pattern accuracy, and environmental adaptability of the heat transfer film by laminating the dielectric enhancement layer 320 between the release layer 200 and the hot melt adhesive layer 400. Specifically, the release layer 200 with a nanoporous layer structure enables thermal-triggered peeling, effectively ensuring the high efficiency of peeling the heat transfer film. The hot melt adhesive layer 400 supported by a ternary blend system enables the hot melt adhesive layer 400 to maintain flexibility in a low-temperature environment. The dielectric enhancement layer 320 added with alumina nanowires can effectively strengthen the abrasion resistance of the heat transfer film, thereby effectively optimizing the mechanical properties of the heat transfer film. At the same time, combined with piezoelectric inkjet in the prior art, the heat transfer film of the present invention can more effectively adsorb ink through the dielectric enhancement layer 320, improving the pattern accuracy and transfer integrity.

[0036] In summary, the heat transfer film with high-efficiency peeling disclosed in the present invention effectively increases the dielectric constant between the pattern layer and the hot melt adhesive layer through the dielectric enhancement layer, thereby significantly enhancing the overall material polarization ability and electrostatic adsorption force of the transfer layer, and further reducing the edge diffusion problem of ink in the pattern layer during the transfer process, improving the adhesion of the transfer layer to application environments such as curved surfaces and porous materials, and improving the transfer accuracy and durability. Specifically, the heat transfer film can achieve thermal-triggered peeling through the release layer with a nanoporous layer structure, effectively ensuring the high efficiency of peeling the heat transfer film. The hot melt adhesive layer supported by a ternary blend system enables the hot melt adhesive layer to maintain flexibility in a low-temperature environment. The dielectric enhancement layer added with alumina nanowires can effectively strengthen the abrasion resistance of the heat transfer film, thereby effectively optimizing the mechanical properties of the heat transfer film. At the same time, combined with piezoelectric inkjet in the prior art, the heat transfer film of the present invention can more effectively adsorb ink through the dielectric enhancement layer 320, improving the pattern accuracy and transfer integrity.

[0037] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0038] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent shall be subject to the appended claims.

Claims

1. A heat transfer film that can be efficiently peeled off, characterized in that, Comprising: A substrate layer, a release layer, a transfer layer, and a hot melt adhesive layer that are sequentially stacked; The transfer layer includes a pattern layer and a dielectric enhancement layer, and the pattern layer and the dielectric enhancement layer are sequentially stacked. Among them, the pattern layer is disposed on the side facing the release layer, and the dielectric enhancement layer is disposed on the side facing the hot melt adhesive layer; The dielectric enhancement layer is set to be a layer structure with a thickness of 3 ± 0.3 μm made of 60% acrylic resin, 30% alumina nanowires, and 10% leveling agent by mass ratio.

2. The heat transfer film capable of being efficiently peeled as claimed in claim 1, wherein The substrate layer is made of a biaxially oriented polyester film (BOPET) with a thickness of 75 ± 2 μm.

3. The heat transfer film capable of being efficiently peeled as claimed in claim 1, wherein The release layer is formed by coating a nano-composite silicone resin on the surface of the substrate layer to form a nano-porous layer structure with a thickness of 10 ± 1 μm.

4. The heat transfer film capable of being efficiently peeled off according to claim 1, wherein The pattern layer is formed by coating UV-curable pigment ink on the surface of the release layer to form a layer structure with a thickness of 5 ± 0.5 μm.

5. The heat transfer film capable of being efficiently peeled as claimed in claim 1, wherein The hot melt adhesive layer is formed by coating a polyester-PU-EVA ternary blend system on the surface of the dielectric enhancement layer to form a layer structure with a thickness of 25 ± 2 μm.

6. A method for preparing a heat transfer film, which is used to prepare the heat transfer film capable of efficient peeling described in any one of claims 1 to 5, and includes the following steps: S1. Plasma-treat the BOPET with argon to increase the surface energy of the substrate and enhance the adhesion of the release layer; then, use an electrostatic dust removal roller combined with a high-pressure ion air knife to perform warning dust removal treatment on the BOPET to obtain the substrate layer; S2. Coat the nano-composite silicone resin on the surface of the substrate layer by microgravure printing, and then cure it by UV for 3 s and post-cure it by infrared for 30 s to obtain the release layer; S3. Spray the UV-curable pigment ink onto the surface of the release layer by an inkjet system, and then cure it by UV for 2 s to obtain the pattern layer; S4. Coat the mixture of acrylic resin, alumina nanowires, and leveling agent mixed in a preset ratio on the surface of the pattern layer by slit extrusion coating, and then cure it by electron beam radiation to obtain the dielectric enhancement layer; S5. Coat the polyester-PU-EVA ternary blend system on the surface of the dielectric enhancement layer by hot melt spraying, and then cool and shape it by a cooling roller for 10 s to obtain the hot melt adhesive layer.

7. The preparation process of the heat transfer film according to claim 6, characterized in that, The argon flow rate in step S1 is set to 15 L / min, the power is set to 2.5 kW, and the processing speed is set to 15 m / min; the cleanliness of the production area is controlled to be Class 100.

8. The hot stamping film preparation process according to claim 6, characterized in that, In the microgravure printing in step S2, a gravure roll with 200 meshes and a coating amount of 12 g / m 2 is used, and the coating speed is set at 25 m / min; for UV curing, a mercury lamp is used and the intensity is set at 120 mW / cm 2 , the wavelength is set at 254 nm; the temperature for infrared post-curing is set at 80 °C.

9. The preparation process of the heat transfer film according to claim 6, characterized in that, The ink in step S3 is cured by UV-LED, with a wavelength set to 385 nm and an intensity set to 1000 mW / cm 2 ; The inkjet system uses a Ricoh MH5420 piezoelectric printhead, and the ink uses Huntsman UV-curable pigment ink.

10. The preparation process of the heat transfer film according to claim 6, characterized in that, The coating temperature in step S4 is set to 120 °C, and the thickness is controlled by an on-line β-ray thickness gauge; the temperature of the cooling roller is set to 15 °C.

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