A full-time tear-off painting film and its preparation method and application

Abstract

This invention belongs to the field of printing materials technology, and provides a time-sensitive peelable heat press film, its preparation method, and its application. The time-sensitive peelable heat press film provided by this invention includes a substrate and a coating. The coating comprises a water-based release layer and a water-based ink carrier layer stacked sequentially from near to far from the substrate. The water-based release layer uses a first wax component, a crosslinking agent, a first filler, and water as its main raw material components, and the water-based ink carrier layer uses a second wax component, a fixing agent, a second filler, and water as its main raw material components. The first wax component has an average particle size of 10-22 μm and a melting point of 90-120℃. The second wax component has an average particle size ≤0.5 μm and a melting point of 70-100℃. This allows for "time-sensitive peeling" effects, including immediate peeling, rapid peeling, delayed peeling, and peeling after cooling, while also meeting environmental protection requirements.

Description

Technical Field

[0001] This invention relates to the field of printing materials technology, and more specifically, to a perpetually peelable heat transfer film, its preparation method, and its application. Background Technology

[0002] Heat transfer film, utilizing the principle of heat transfer printing, transfers patterns onto other substrates (such as fabrics or other materials). Based on the peeling method from the substrate, heat transfer film can be categorized into hot-peel film, cold-peel film, and instant-peel film. Currently, heat transfer films that support multiple peeling methods simultaneously (e.g., instant peeling at around 130℃, hot peeling at around 110℃, warm peeling at around 60-80℃, and cold peeling at room temperature, supporting at least two of these methods) are available. Their core advantages lie in their flexible operational adaptability and high-quality transfer effects (such as strong color expression, soft touch, and washability and abrasion resistance), making them the preferred choice for high-efficiency digital heat transfer printing. Due to their multiple peeling methods, strict control of peeling time during transfer is unnecessary, significantly improving production efficiency.

[0003] Most heat transfer films currently known to support multiple peeling methods contain oil-based release agents. For example, Chinese patent (publication number CN116162400A) discloses a heat transfer film that adds a modified silicone wax polymer as the main release agent to achieve instant and cold peeling. However, since it uses a modified silicone wax polymer as the release agent, its temperature resistance is poor, and it only supports instant and cold peeling, not hot or warm peeling, limiting the peeling methods. Chinese patent (publication number CN118810269A) discloses a heat transfer film using thermosetting resin, silicone oil, and wax powder as the main release agent. Although it supports instant, hot, warm, and cold peeling, its release coating is an oil-based coating, which contains volatile organic compounds that pollute the environment, making it unsuitable for scenarios with high environmental protection requirements.

[0004] Therefore, there is an urgent need to develop an all-time tear-off heat transfer film that is environmentally friendly, free of volatile organic compounds, and supports multiple peeling methods such as instant tearing, hot tearing, warm tearing, and cold tearing. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an all-time tear-off heat transfer film, its preparation method, and its application. The all-time tear-off heat transfer film provided by this invention uses water as a solvent for all coatings, resulting in no volatile organic compound pollution, excellent environmental friendliness, and supports multiple peeling methods including instant peeling, hot peeling, warm peeling, and cold peeling, achieving "all-time tearing".

[0006] The first aspect of the present invention provides a always-on peelable heat-transfer film.

[0007] Specifically, a real-time peel-off heat-transfer film includes a substrate and a coating, wherein the coating comprises a water-based release layer and a water-based ink-carrying layer stacked sequentially from near to far from the substrate;

[0008] The aqueous release layer comprises the following raw material components: a first wax component, a crosslinking agent, a first filler, and water;

[0009] The water-based ink carrier layer comprises the following raw material components: a second wax component, a fixing agent, a second filler, and water;

[0010] The average particle size of the first wax component is 10-22 μm; the melting point of the first wax component is 90-120℃.

[0011] The average particle size of the second wax component is ≤0.5μm; the melting point of the second wax component is 70-100℃;

[0012] The fixing agent is an organosiloxane-modified acrylic emulsion with a core-shell structure.

[0013] This invention employs two distinct water-based coatings: a water-based release layer and a water-based ink carrier layer, both using water as a solvent, achieving a fully water-based system and avoiding the use of organic solvents. The combined action of these two water-based coatings provides release effects at different temperature zones, enabling "all-time peeling." This means that the heat transfer film can be peeled off immediately after pressing onto the transfer carrier and remains peelable even after cooling to room temperature. Essentially, the peelable time covers the entire period from the end of pressing to room temperature. The main structural components of both the water-based release layer and the water-based ink carrier layer are wax. After transfer, the wax component in the coatings primarily provides the peeling force, allowing the heat transfer film to be peeled off at various stages after transfer. Multiple peeling methods are supported, as detailed below:

[0014] (1) Just after the heat pressing is finished, the surface temperature of the heat transfer film is still high, reaching about 130°C. At this time, all the wax components in the coating are in a molten state. The molten wax components provide fluidity, significantly reduce the interfacial interaction with the substrate, and provide the main peeling force. At this time, the heat transfer film and the base film are easy to separate, and can be easily peeled off at 130°C, which is called "second tear" (can be torn off in less than or equal to 1 second after the heat pressing is finished).

[0015] (2) As the surface temperature of the hot-pressed substrate gradually decreases (to about 110°C), the wax component in the hot-press film coating remains in a molten state, and all the wax components still provide the main peeling force, making it easy to separate. This is called "hot tear".

[0016] (3) When the surface temperature of the heat transfer film continues to drop to about 60-80℃, the wax component is in a complex state of "partially solidifying while partially still melting". Since the size of the second wax component in the water-based ink carrier layer is smaller than that in the water-based release layer, as the cooling time increases and the migration characteristics of wax are utilized, the second wax component in the water-based ink carrier layer will continuously penetrate into the first wax component in the water-based release layer, causing more wax components to seep out and gather at the interface close to the substrate. At the same time, the "self-healing ability" of the wax component after melting can gradually restore its original form as the temperature drops, and can continue to provide peeling force at a temperature of 60-80℃ to achieve "warm peeling".

[0017] (4) After the surface temperature of the heat transfer film drops to room temperature, all the wax components lose fluidity. The larger wax components in the water-based release layer provide skeletal support, and the smaller wax components that migrate to the water-based release layer can fill the structural gaps, making the two coatings bond more firmly. The water-based release layer that fills the structural gaps greatly reduces its surface energy, which reduces the interaction force between it and the substrate, thus enabling transfer peeling (and usually there is also the driving effect of hot melt adhesive and ink layer during peeling, which further helps peeling), i.e., "cold peeling".

[0018] Therefore, the all-time peelable heat press film of the present invention, under the combined action of the water-based release layer and the water-based ink carrier layer, can support multiple peeling methods such as instant peeling after hot pressing, hot peeling, warm peeling, and cold peeling, thus achieving all-time peeling. In addition, the organosiloxane-modified acrylic emulsion with a core-shell structure, used as a fixing agent, increases the crosslinking density and adhesion with the wax component, reduces the peel strength of the coating, not only assists in the peeling of the wax component, but also improves the color fastness and adhesion of the water-based ink, thereby improving the ink fixing ability of the water-based ink carrier layer.

[0019] Preferably, the average particle size of the first wax component is 15-22 μm.

[0020] Preferably, the average particle size of the second wax component is ≤0.2μm.

[0021] Preferably, the melting point of the first wax component is 100-110℃.

[0022] Preferably, the melting point of the second wax component is 80-90°C.

[0023] Preferably, the wax components in the water-based release layer and the water-based ink carrier layer are independently selected from wax powder and / or wax emulsion, respectively.

[0024] More preferably, the wax component of the water-based release layer is wax powder.

[0025] More preferably, the wax component in the water-based ink carrier layer is a wax emulsion.

[0026] Preferably, the water-based release layer comprises the following raw material components by weight: 50-70 parts of the first wax component, 15-35 parts of the crosslinking agent, 1-30 parts of the first filler, and 80-120 parts of water.

[0027] More preferably, the water-based release layer comprises the following raw material components by weight: 55-65 parts of the first wax component, 20-30 parts of the crosslinking agent, 5-25 parts of the first filler, and 90-110 parts of water.

[0028] More preferably, the water-based release layer comprises the following raw material components by weight: 60-65 parts of the first wax component, 26-30 parts of the crosslinking agent, 10-20 parts of the first filler, and 100-110 parts of water.

[0029] Preferably, the water-based release layer further includes a thickener and a leveling agent.

[0030] More preferably, the water-based release layer further includes 0.1-1 parts thickener and 1-5 parts leveling agent by weight.

[0031] More preferably, the water-based release layer further comprises 0.5-1 parts thickener and 3.5-5 parts leveling agent by weight.

[0032] Preferably, the water-based ink carrier layer comprises the following raw material components by weight: 35-55 parts of second wax component, 10-30 parts of fixing agent, 15-35 parts of second filler, and 80-120 parts of water.

[0033] More preferably, the water-based ink carrier layer comprises the following raw material components by weight: 40-50 parts of second wax component, 15-25 parts of fixing agent, 20-30 parts of second filler, and 90-110 parts of water.

[0034] More preferably, the water-based ink carrier layer comprises the following raw material components by weight: 45-50 parts of second wax component, 20-25 parts of fixing agent, 25-30 parts of second filler, and 100-110 parts of water.

[0035] Preferably, the water-based ink carrier layer further includes a wetting agent.

[0036] More preferably, the water-based ink carrier layer further includes 5-15 parts of wetting agent by weight.

[0037] More preferably, the aqueous ink carrier layer further includes 10-15 parts of wetting agent by weight.

[0038] Preferably, the wax powder is at least one of polyethylene wax powder, polyethylene oxide wax powder, polyamide wax powder, Fischer-Tropsch wax, polypropylene wax powder, and ethylene / propylene copolymer wax powder.

[0039] Preferably, the wax emulsion is at least one of polyethylene wax emulsion, montan wax emulsion, cationic acrylic wax emulsion, palm wax emulsion, and polyamide wax emulsion.

[0040] Preferably, the crosslinking agent is an isocyanate crosslinking agent (such as BYK-C 8014 crosslinking agent produced by BYK Chemicals).

[0041] More preferably, the crosslinking agent is an aliphatic isocyanate crosslinking agent. Aliphatic isocyanate crosslinking agents can establish highly dense chemical crosslinking points between the polyethylene chains in the release layer, improving the mechanical strength of the release layer coating and increasing its scratch resistance. Furthermore, compared to other crosslinking agents, aliphatic isocyanate crosslinking agents, due to their excellent chain structure, exhibit excellent resistance to yellowing and good gloss and color retention, providing a certain degree of protection during the transportation and storage of heat transfer film products.

[0042] Preferably, the thickener is a polyethylene oxide-based thickener. Compared to other water-soluble thickeners, polyethylene oxide-based thickeners have the significant advantages of excellent water solubility and high thickening efficiency at low concentrations. They can achieve efficient thickening of water-based release coatings at low addition amounts, while having a negligible impact on release force due to the small addition amount. Therefore, they do not hinder wax removal during heat transfer printing.

[0043] Preferably, the leveling agent is an acetylenic glycol ethoxylate leveling agent. Acetylene glycol ethoxylate provides wetting and leveling in the release layer, does not introduce silicone components, and has low / no foaming properties, eliminating the need for defoamers that could affect wax release. Furthermore, its excellent dispersibility allows for superior dispersion of wax components such as polyethylene wax powder in water, slowing down the rising time of the wax components and extending the shelf life of the coating. In addition, compared to mineral oil and polysiloxane leveling agents, it does not create defects on the coating surface, such as pinholes or fisheyes, contributing to the integrity of the pattern after heat transfer film transfer.

[0044] Preferably, the wetting agent is an organosilicon wetting agent.

[0045] More preferably, the wetting agent is an acetylenic diol modified organosilicon wetting agent. Acetylene diol modified organosilicon wetting agents have good wetting effects; adding a small amount to the release layer can achieve excellent wetting results. They are non-foaming, eliminating the need to add defoamers to the components and thus avoiding affecting the coating effect.

[0046] Preferably, the first filler is zinc stearate.

[0047] Preferably, the second filler is zinc stearate and fumed silica.

[0048] Preferably, the mass ratio of zinc stearate to fumed silica is 1:(3-5).

[0049] More preferably, the mass ratio of zinc stearate to fumed silica is 1:(4-5).

[0050] The addition of zinc stearate to the water-based release layer facilitates wax release by providing internal lubrication and thermal stability without affecting coating transparency. Gaseous silica, added to the water-based ink carrier layer, utilizes its excellent nanostructure to achieve an organic-inorganic composite effect with wax components and fixing agents, enhancing the mechanical properties of the coating while improving the color-fixing effect on pigment inks.

[0051] Preferably, the substrate is one of polyethylene terephthalate (PET) film, polyurethane (PU) film, and polyvinyl chloride (PVC) film.

[0052] A second aspect of the present invention provides a method for preparing a always-on peelable heat-transfer film.

[0053] A method for preparing a peelable heat-transfer film includes the following steps:

[0054] The raw material components of the water-based release layer and the water-based ink carrier layer are mixed separately to obtain the water-based release layer coating and the water-based ink carrier layer coating, respectively. Then, the water-based release layer coating and the water-based ink carrier layer coating are sequentially coated on the surface of the substrate to obtain the water-based release layer and the water-based ink carrier layer, respectively. After drying, the all-time peelable heat transfer film is obtained.

[0055] Preferably, a water-based release coating is first applied to the surface of the substrate and dried first, and then a water-based ink carrier coating is applied and dried second to obtain the all-time peel-off heat transfer film.

[0056] Preferably, the application rate of the water-based release coating is 1-3 g / m². 2 .

[0057] More preferably, the coating amount of the water-based release layer coating is 2-3 g / m². 2 .

[0058] Preferably, the coating amount of the water-based ink carrier layer is 2-4 g / m². 2 .

[0059] More preferably, the coating amount of the water-based ink carrier layer is 3-4 g / m². 2 .

[0060] Preferably, the temperature of the first drying is 110-130°C, and / or the drying time is 1-10 min.

[0061] More preferably, the temperature of the first drying is 120-130°C, and / or the drying time is 5-10 min.

[0062] Preferably, the temperature of the second drying is 110-130°C, and / or the drying time is 1-5 min.

[0063] More preferably, the temperature of the second drying is 120-130°C, and / or the drying time is 1-3 minutes.

[0064] A third aspect of the present invention provides an application of a always-on peelable heat-transfer film.

[0065] Application of a type of always-on peelable heat transfer film in printing materials, packaging materials, decorative materials or building materials.

[0066] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0067] The present invention provides a fully peelable heat-transfer film comprising a substrate and a coating. The coating comprises a water-based release layer and a water-based ink carrier layer stacked sequentially from near to far from the substrate. The water-based release layer uses a first wax component, a crosslinking agent, a first filler, and water as the main raw material components, and the water-based ink carrier layer uses a second wax component, a fixing agent, a second filler, and water as the main raw material components. The first wax component has an average particle size of 10-22 μm and a melting point of 90-120°C. The second wax component has an average particle size ≤0.5 μm and a melting point of 70-100°C. Because the wax components in the water-based release layer are larger in size than those in the water-based ink carrier layer, the smaller wax emulsions in the water-based ink carrier layer can embed into the structural gaps of the larger wax powders in the water-based release layer during high-temperature hot pressing. This allows them to better exert a synergistic release effect during hot pressing and melting. Furthermore, both wax components are low-melting-point mixed waxes with low melting points and wide melting temperatures, allowing them to remain in a molten state for a longer period during hot pressing, providing release force for instant peeling, hot peeling, and warm peeling. Cold peeling is also possible after cooling to room temperature. This invention's all-time peelable heat transfer film can achieve multiple peeling effects after heat transfer: instant peeling (instant peeling at around 130°C), rapid peeling (hot peeling at around 110°C), delayed peeling (warm peeling at around 60-80°C), and peeling after cooling (cold peeling at room temperature), achieving "all-time peeling." It also features excellent ink retention (no ink flow or accumulation when printing with ink from an ink cartridge), non-stickiness (no sticking to hot melt adhesive powder under high temperature and humidity), and high-fidelity image reproduction. In addition, both coating layers of the present invention use water as a solvent, making them "all-water-based" products with no volatile organic compound (VOC) emissions. They are environmentally friendly, meet environmental protection requirements, and are suitable for application scenarios with high environmental protection requirements, such as white ink direct-to-garment heat transfer printing. Attached Figure Description

[0068] Figure 1This is a schematic diagram of the structure of the all-time tear-off heat-transfer film prepared in Embodiment 1 of the present invention;

[0069] Figure 2 This is a schematic diagram of the structure of the all-time tear-off heat-transfer film of Embodiment 1 of the present invention when it is torn at a temperature of 60-80°C after being heat-pressed;

[0070] Figure 3 This is a schematic diagram of the structure of the all-time tear-off heat-transfer film of Embodiment 1 of the present invention when it is cold-torn at room temperature after being heat-pressed. Detailed Implementation

[0071] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0072] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0073] The parameters and sources of the specific raw materials used in this invention are as follows:

[0074] Wax Powder 1: Polyethylene wax powder, melting point 100-110℃, average particle size 10-22μm, manufacturer Guangzhou Binlong Chemical Co., Ltd., model E-610;

[0075] Wax powder 2: Polyethylene wax powder, melting point 100-110℃, average particle size 6-7.5μm, manufacturer: Kaimifu Chemical Co., Ltd.

[0076] Wax powder 3: Fischer-Tropsch wax, melting point 100-110℃, average particle size 4-5μm, manufacturer Yangting New Material Technology Co., Ltd.;

[0077] Wax powder 4: Polyamide wax powder, melting point 130-140℃, average particle size 3-5μm, manufacturer Yangting New Material Technology Co., Ltd.;

[0078] Wax Powder 5: Polyoxyethylene wax powder, melting point 120-140℃, average particle size 15-20μm, manufacturer Yangting New Material Technology Co., Ltd.

[0079] Wax Powder 6: Ethylene / propylene copolymer wax powder, melting point 150-160℃, average particle size 15μm, manufacturer Yangting New Material Technology Co., Ltd.

[0080] Wax emulsion 1: Polyethylene wax emulsion, melting point 80-90℃, average particle size ≤0.5μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0081] Wax emulsion 2: Polyethylene wax emulsion, melting point 80-90℃, average particle size 6-8μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0082] Wax emulsion 3: Cationic polyacrylic acid wax emulsion, melting point 150-160℃, average particle size ≤0.1μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0083] Wax emulsion 4: Palm wax emulsion, melting point 75-85℃, average particle size ≤0.5μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0084] Wax emulsion 5: Mondan wax emulsion, melting point 70-80℃, average particle size ≤0.2μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0085] Wax Emulsion 6: Polyamide wax emulsion, melting point 100-110℃, average particle size 5μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0086] Wax emulsion 7: Polyamide wax emulsion, melting point 80-90℃, average particle size ≤0.5μm, manufacturer: Yijiu Environmental Protection Technology Co., Ltd.

[0087] Fixing agent 1: Organosiloxane modified acrylic emulsion with core-shell structure, manufactured by Nanxing Chemical Co., Ltd.

[0088] Fixing agent 2: Magnesium sulfate, analytical grade, manufactured by McLean Company;

[0089] Fixing agent 3: Magnesium chloride, analytical grade, manufactured by McLean Company;

[0090] Fixing agent 4: Polyaluminum chloride, manufactured by Tongjiang Chemical Co., Ltd.;

[0091] Fixing agent 5: Epoxy resin modified polyurethane, manufactured by Wanhua Chemical Group Co., Ltd.

[0092] Crosslinking agent: Isocyanate crosslinking agent, manufactured by BYK Chemical, model number BYK-C 8014;

[0093] Leveling agent: Acetylene glycol ethoxylate leveling agent, manufactured by Wuhan Jihechang New Material Co., Ltd., model TL-607;

[0094] Wetting agent: Organosilicon wetting agent, manufactured by Wuhan Aoke Special Chemical Co., Ltd., model number JC7000;

[0095] Thickener: Polyoxyethylene thickener, manufactured by Sumitomo Seika Chemicals Co., Ltd., model number PEO-8;

[0096] Filler 1: Zinc stearate, commercially available;

[0097] Filler 2: Gaseous silica, commercially available.

[0098] Example 1

[0099] A type of always-on peelable heat transfer film is composed of a substrate, a water-based release layer, and a water-based ink carrier layer stacked sequentially.

[0100] The substrate is a PET film with a thickness of 60μm;

[0101] The raw material components of the water-based release layer and the water-based ink carrier layer are shown in Table 1 below.

[0102] The above-mentioned method for preparing the all-time peelable heat-transfer film includes the following steps:

[0103] (1) Preparation of water-based release coating: Water, thickener, crosslinking agent, wax powder, first filler and leveling agent are added to the mixing tank in sequence and stirred. After stirring, the mixture is filtered and defoamed.

[0104] (2) Preparation of water-based ink carrier coating: Water, wetting agent, wax emulsion, color fixing agent and second filler are added to the mixing tank in sequence and stirred. After stirring, the mixture is filtered and defoamed.

[0105] (3) Preparation of a fully peelable heat-sealing film: The two coatings prepared above are applied, and the coating amount of the water-based release layer is controlled to be 2.0 g / m. 2 The coating weight of the water-based ink carrier layer is 3.0 g / m². 2 The total coating coverage is 5.0 g / m². 2 Specifically, the water-based release coating is applied to the PET film and dried at 120°C for 5 minutes. Then, the water-based ink carrier coating is applied to the dried water-based release layer and dried at 120°C for 3 minutes to obtain a fully peelable heat transfer film (due to the low drying temperature and short drying time, the wax component did not melt over a large area).

[0106] like Figure 1 As shown, the all-time peelable heat transfer film is composed of a PET film, a water-based release layer, and a water-based ink carrier layer stacked in sequence. The main structural component of the water-based release layer is wax powder, and the main structural component of the water-based ink carrier layer is wax emulsion. These two wax components provide the main peeling force.

[0107] like Figure 2 As shown, when the substrate temperature is 60-80℃, by utilizing the migration characteristics of wax, the small-sized wax emulsion in the water-based ink carrier layer can better penetrate into the spaces between the large-sized wax powders in the water-based release layer, allowing more wax to seep out to the interface near the substrate after being heated and pressed. Utilizing this self-healing ability of wax, it can continue to provide peeling force at a temperature of 60-80℃, achieving warm peeling.

[0108] like Figure 3As shown, after the substrate temperature drops to room temperature, the wax component loses its fluidity. The large-sized wax powder in the water-based release layer provides skeletal support, and the small-sized wax emulsion that migrates to the water-based release layer can fill the structural gaps, making the two coatings bond more firmly. Moreover, the water-based release layer that fills the structural gaps greatly reduces its surface energy, thereby reducing its interaction force with the substrate. During the release process, the transfer can be achieved by the hot melt adhesive and the ink layer (ink pattern).

[0109] Examples 2-8

[0110] Examples 2-8 provide a tear-off heat-transfer film that differs from Example 1 in that the raw material composition is different, as shown in Tables 1 and 2 below.

[0111] Comparative Examples 1-16

[0112] Comparative Examples 1-16 provide heat transfer films, which differ from Example 1 in that the raw material components are different, as shown in Tables 1 and 2 below.

[0113] Table 1. Raw material components and their dosage (parts by weight) for each group

[0114]

[0115] Table 2. Raw material components and their dosage (parts by weight) for each group

[0116]

[0117] Product effectiveness test

[0118] 1. Full-time tear performance

[0119] (1) Test method

[0120] The heat transfer films prepared in the above embodiments and comparative examples, from front to back, sequentially comprise an aqueous ink carrier layer, an aqueous release layer, and a substrate. After printing a pattern on the front of the heat transfer film, the printed pattern is baked at 40-60℃ for 2 minutes. Then, hot melt adhesive powder (TPU powder, manufactured by Zhejiang Aoyu New Material Technology Co., Ltd., Grade A white film heat transfer powder) is sprinkled on, and the hot melt adhesive powder is melted at 130℃. On the back of the heat transfer film, the printed pattern is pressed using a heat press plate at 155℃ and 0.2MPa for 8 seconds. Press the heat press onto the pure cotton fabric (transfer carrier), and the heat pressing ends when the heat press plate is removed. The timer starts from the end of the heat pressing (T0) and continues until the time (T1) when the heat transfer film is peeled off the pure cotton fabric. The time from T0 to T1 is recorded as T (i.e., T = T1 - T0). T = 0-1s indicates that the film surface temperature drops to about 130℃ and is peeled off in seconds; T = 8s indicates that the film surface temperature drops to about 110℃ and is peeled off hot; T = 16s indicates that the film surface temperature drops to about 60-80℃ and is peeled off warmly; T > 30s indicates that the film surface temperature drops to room temperature and is peeled off cold.

[0121] When peeling off the heat transfer film, if no pattern remains on the film, it is recorded as peelable (recorded as "peelable"), and if pattern remains, it is recorded as non-peelable (recorded as "non-peelable"). The test results are shown in the table below.

[0122] (2) Test results

[0123] Table 3 Performance test results of heat transfer film in each embodiment

[0124]

[0125] Table 4 Performance test results of heat transfer films for each comparison example

[0126]

[0127] Table 5 Performance test results of heat transfer films for each comparison example

[0128]

[0129] As can be seen from the table above, the heat transfer film of embodiments 1-8 of the present invention can be peeled off immediately after the heat transfer is completed, and can be peeled off at any time during the process from the end of the heat transfer to the temperature drop to room temperature. That is, it can support multiple peeling methods such as instant peeling, hot peeling, warm peeling and cold peeling, and realize "all-time peeling".

[0130] Compared to Example 1, the wax powder particles in the water-based release layer of Comparative Examples 1, 2, and 3 are too small to achieve warm peeling, and cannot be peeled off at any time after the hot pressing is completed; they can only be peeled off instantly or hot. This is because when the wax powder particles in the water-based release layer are too small and densely packed with almost no gaps, the wax emulsion in the water-based ink carrier layer cannot migrate into the water-based release layer. Without enough wax components migrating to the substrate interface, a long-term release effect cannot be maintained, and warm or cold peeling is not possible.

[0131] Compared with Example 1, the wax powder of the water-based release layer in Comparative Examples 4 and 5 has an excessively high melting point. After the hot pressing is completed, the temperature drops and the molten wax quickly loses its fluidity. As a result, the water-based release layer does not have enough molten wax to provide release force, and cannot achieve instant tearing, hot tearing, warm tearing, or cold tearing.

[0132] Compared with Example 1, the fixing agent of the water-based ink carrier layer in Comparative Examples 6-9 did not use an organosiloxane modified acrylic emulsion with a core-shell structure. As a result, it could not form a dense coating structure with the ink and wax components after printing, resulting in a low crosslinking density of the wax components. This increased the peel strength of the coating and hindered the warm and cold peeling processes, making it impossible to achieve warm and cold peeling, i.e., it could not achieve "all-time peel".

[0133] Compared with Example 1, the wax emulsion particles in the water-based ink carrier layers of Comparative Examples 10, 12, 13, and 16 were too large or had too high melting points. If the wax emulsion particles were too large, they could not achieve the embedding between the wax emulsion in the water-based ink carrier layer and the wax powder in the water-based release layer. There was not enough molten wax to provide release force, so the long-term release effect could not be achieved and the "all-time tear" could not be realized.

[0134] Compared with Example 1, the wax emulsion in the water-based ink carrier layer of Comparative Examples 11 and 14 has a higher melting point. After hot pressing, the temperature drops and the wax emulsion quickly loses its fluidity and cannot fully penetrate into the water-based release layer. As a result, there is not enough molten wax in the release layer to provide release force during warm and cold peeling, so warm and cold peeling cannot be achieved and "full-time peeling" cannot be achieved.

[0135] Compared with Example 1, the wax powder particles of the water-based release layer in Comparative Example 16 are too small, the wax emulsion of the water-based ink carrier layer has too large a particle size and too high a melting point, and the nesting effect of the coating structure of the water-based release layer and the water-based ink carrier layer is weak. During hot pressing, only the molten wax closest to the substrate in the water-based release layer provides a weak release force, making it impossible to achieve hot and warm peeling. After cooling to room temperature, the lack of strong interaction between the two coatings and the ink also makes it impossible to completely peel the pattern off the substrate, and cold peeling is not possible.

[0136] 2. Volatile organic compounds (VOCs)

[0137] Test method: The VOCs of the heat transfer film of Example 1 were tested according to YC / T 207-2014 "Determination of solvent residues in tobacco paper by headspace-gas chromatography / mass spectrometry".

[0138] The test results of Example 1 are shown below:

[0139] Table 6. VOCs test results of Example 1

[0140]

[0141] Note: "-" in the table above indicates that it was not detected.

[0142] As shown in the table above, no harmful organic pollutants such as toluene and xylene were detected in the all-time tear-off heat-sealing film of Example 1 of the present invention, which meets the environmental protection requirements.

[0143] The coatings of the all-time peelable heat-sealing films in Examples 2-8 all use water as a solvent, and the detection results of their organic pollutants are comparable to those in Example 1, meeting environmental protection requirements.

[0144] 3. Coating effect

[0145] The all-time peelable heat-resistant film prepared in Example 1 was tested as follows:

[0146] Haze: GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics".

[0147] Transmittance: GB / T 2410-2008 "Determination of transmittance and haze of transparent plastics".

[0148] Peel strength: GB / T 2792-2014 "Test method for peel strength of adhesive tape".

[0149] The results showed that the haze of the full-time peelable heat-transfer film of Example 1 was 95.8%, the transmittance was 87.4%, and the peel strength was 20 N / m.

[0150] 4. Printing performance

[0151] (1) Ink fixation effect: Take the heat transfer film of Example 1 and print a pattern on the front of the heat transfer film using Moku Digital Heat Transfer Paint (DTF ink). The results show that when the white ink coverage is set to 100%, there is no ink flow or ink accumulation, and the ink fixation is excellent.

[0152] (2) Non-sticky: Take the heat transfer film of Example 1, print a pattern on its front side, place it in a high humidity environment of 26°C and >90%RH, sprinkle hot melt adhesive powder on the front side of the heat transfer film, and after drying, it was found that there was no hot melt adhesive powder residue in the non-pattern printing area of ​​the heat transfer film. This indicates that the heat transfer film of Example 1 is non-sticky.

[0153] (3) Pattern fidelity: Take the front side of the heat transfer film of Example 1, print a pure blue block (RGB: 0, 0, 255), and then transfer it onto gray pure cotton fabric. The results, tested with a light density colorimeter, show that its sensitive color C value is 1.45-1.50. This indicates that the pattern printed using the heat transfer film of Example 1 has good fidelity.

[0154] In summary, the all-time tear-off heat transfer film provided by this invention not only supports multiple peeling methods such as instant tearing, hot tearing, warm tearing, and cold tearing, but also has a good coating effect. Furthermore, when used for printing, the all-time tear-off heat transfer film has excellent ink fixation performance, and the printed pattern does not become sticky. Moreover, the printed pattern is of high fidelity and has a good printing effect.

Claims

1. An all-time decal film, characterized by, It includes a substrate and a coating, wherein the coating comprises a water-based release layer and a water-based ink carrier layer stacked sequentially from the nearest to the farthest from the substrate; The aqueous release layer comprises the following raw material components: a first wax component, a crosslinking agent, a first filler, and water; the first wax component is wax powder; The water-based ink carrier layer comprises the following raw material components: a second wax component, a fixing agent, a second filler, and water; the second wax component is a wax emulsion. The average particle size of the first wax component is 10-22 μm; the melting point of the first wax component is 100-110℃. The average particle size of the second wax component is ≤0.5μm; the melting point of the second wax component is 80-90℃; The fixing agent is an organosiloxane-modified acrylic emulsion with a core-shell structure.

2. The all-time peelable heat-transfer film according to claim 1, characterized in that, The average particle size of the first wax component is 15-22 μm, and the average particle size of the second wax component is ≤0.2 μm.

3. The all-time peelable heat-transfer film according to claim 1, characterized in that, The water-based release layer comprises the following raw material components by weight: 50-70 parts of the first wax component, 15-35 parts of the crosslinking agent, 1-30 parts of the first filler, and 80-120 parts of water.

4. The all-time peelable heat-transfer film according to claim 1, characterized in that, The water-based ink carrier layer comprises the following raw material components by weight: 35-55 parts of second wax component, 10-30 parts of fixing agent, 15-35 parts of second filler, and 80-120 parts of water.

5. The all-time peelable heat-transfer film according to claim 1, characterized in that, The wax powder is at least one of polyethylene wax powder, polyethylene oxide wax powder, polyamide wax powder, Fischer-Tropsch wax, polypropylene wax powder, and ethylene / propylene copolymer wax powder.

6. The all-time peelable heat-transfer film according to claim 1, characterized in that, The wax emulsion is at least one of polyethylene wax emulsion, montan wax emulsion, cationic acrylic wax emulsion, palm wax emulsion, and polyamide wax emulsion.

7. The all-time peelable heat-transfer film according to claim 1, characterized in that, The first filler is zinc stearate, and / or the second filler is zinc stearate and fumed silica.

8. The method for preparing the all-time peelable heat-transfer film according to any one of claims 1-7, characterized in that, Includes the following steps: The raw material components of the water-based release layer and the water-based ink carrier layer are mixed separately to obtain the water-based release layer coating and the water-based ink carrier layer coating, respectively. Then, the water-based release layer coating and the water-based ink carrier layer coating are sequentially coated on the surface of the substrate to obtain the water-based release layer and the water-based ink carrier layer, respectively. After drying, the all-time peelable heat transfer film is obtained.

9. The use of the all-time tear-off heat-sealing film according to any one of claims 1-7 in printing materials, packaging materials, decorative materials or building materials.

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