TWI910046B - Transfer membrane - Google Patents

Abstract

This invention relates to a transfer film comprising a carrier layer and a transfer layer; the transfer layer is disposed on the inner surface of the carrier layer and is detachable from the carrier layer; wherein the transfer layer comprises a release layer and a coloring layer, the release layer being in contact with the inner surface of the carrier layer; wherein the average thickness of the carrier layer is 2 micrometers to 10 micrometers; and the average thickness of the transfer layer is 0.5 micrometers to 0.9 micrometers. By employing the aforementioned technique, this invention achieves the advantage of good edge trimming, thus reducing material consumption and consequently lowering carbon emissions and energy consumption.

Description

Transfer membrane

This invention relates to a composite layer, and more particularly to a transfer film that is decorative and can transfer one or more multilayers onto a target substrate.

As modern society places increasing demands on the aesthetics and functionality of materials, the market demand for decorative films, which can be widely applied in various fields, is growing, and their application areas are becoming increasingly diverse. For example, to ensure the security of documents such as banknotes, passports, ID cards, credit cards, or certificates, decorative films are often transferred onto the target substrate to form single-layer or multi-layer structures, presenting a special visual effect. In addition, transfer films displaying specific patterns or text are often transferred onto the surface of soft materials such as leather and velvet to impart color and highlight the design; or, cosmetics, wine bottles, food gift boxes, and other products especially need eye-catching packaging designs to attract consumers' attention and create a high-end image, in which case transfer films are often used to transfer these designs onto the packaging.

The aforementioned transfer films are typically designed for different applications, allowing factories to cut rolls of transfer film into the required sizes. However, if the transfer film has poor edge cutting properties, such as producing large dust particles at the edges after cutting, it will not only increase the consumption of raw materials, but the dust particles may also cause physical strain on the operators; or the dust particles may clog the printing plate, resulting in poor transfer effects and an inability to achieve good print quality.

Therefore, there is still room for improvement in the edge-cutting properties and printing quality of transfer films to achieve lean production, thereby reducing material consumption and energy waste, in order to meet the expectations of today's enterprises for sustainable development.

In view of the shortcomings of existing technology, one of the purposes of this invention is to provide a transfer film with good edge cutting properties, which can reduce material consumption, thereby reducing carbon emissions and energy consumption, while also improving the safety of operators in the process.

One of the objectives of this invention is to provide a transfer membrane that, by reducing its thickness in the transfer layer, can reduce the amount of coatings and solvents used and reduce the difficulty of waste membrane recycling, thereby achieving environmental friendliness and reducing carbon emissions, and has the potential for commercial implementation.

To achieve the aforementioned objective, the present invention provides a transfer film comprising: a carrier layer; and a transfer layer disposed on the inner surface of the carrier layer and detachable from the carrier layer; wherein the transfer layer comprises a release layer and a coloring layer, the release layer being in contact with the inner surface of the carrier layer; wherein the average thickness of the carrier layer is from 2 micrometers (μm) to 10 μm; and the average thickness of the transfer layer is from 0.5 μm to 0.9 μm.

By controlling the average thickness range of the carrier layer and the transfer layer, which includes the release layer and the coloring layer, it is possible to reduce the size of broken dust particles generated at the cut edge of the transfer film during cutting, thereby reducing material consumption and improving cost-effectiveness. Furthermore, the improved cutability of the transfer film during the transfer process also results in better dot packing and improved transfer quality. In addition, this invention reduces the overall thickness of the transfer layer, thereby reducing the amount of organic coatings and solvents used, thus offering environmental friendliness.

Optionally, the material of the carrier layer may include polyethylene terephthalate (PET), polyethylene (PE), polystyrene (PS), polyimide (PI), polylactic acid (PLA), polybutylene succinate (PBS), polyacrylonitrile (PAN), polyurethane (PU), polycarbonate (PC), polyvinyl chloride (PVC), glass, stone paper, or combinations thereof, but is not limited thereto. In some embodiments, the aforementioned carrier layer material may be either virgin material or recycled material; furthermore, recycled materials may be further classified into "post-industrial recycling (PIR)" and "post-consumer recycling (PCR)" depending on the stage of recycling. For example, the material of the carrier layer may include recycled PET (r-PET), but is not limited to this.

Optionally, the average thickness of the carrier layer can be from 2 μm to 7 μm, but is not limited thereto. For example, the average thickness of the carrier layer can be 2.5 μm, 3.2 μm, 4.5 μm, 5.6 μm or 6 μm, but is not limited thereto.

In some embodiments, the haze of the carrier layer may be between 2.5% and 7.5%, but is not limited thereto. The aforementioned haze may be measured by the standard method ASTM D1003.

Preferably, the rheological tan δ value (30°C) of at least one of the release coating forming the release layer and the coloring coating forming the coloring layer is from 0.1 to 1, but is not limited thereto. More preferably, the rheological tan δ value (30°C) of the release coating and the coloring coating is independently from 0.1 to 1, that is, the rheological tan δ value (30°C) of the release coating and the coloring coating is both from 0.1 to 1, and the two can be the same or different. By further controlling the rheological properties (tan δ) of the release layer coating and/or the coloring layer coating within the aforementioned range, the heat transfer performance of the transfer film can be maintained even if the transfer layer has a thinner average thickness than that of the prior art transfer layer, and the transfer film can even have better heat transfer performance.

In some embodiments, the rheological tan δ value (30°C) of the release coating may be from 0.35 to 0.8, but is not limited thereto. In some embodiments, the rheological tan δ value (30°C) of the coloring coating may be from 0.4 to 0.97, but is not limited thereto. Preferably, the rheological tan δ value (30°C) of the coloring coating is greater than that of the release coating.

In some embodiments, the release coating may comprise (meth)acrylic resin, polyurethane polymer resins dispersed in water (PUDs), styrene-maleic anhydride copolymer (SMA resin), cellulose acetate, rosin resin, chlorinated polypropylene (CPP), polycarbonate (PC), or combinations thereof, but is not limited thereto. Specifically, the polyurethane dispersion may be a waterborne polyurethane dispersion; further, the polyurethane dispersion may comprise a silica-modified waterborne polyurethane dispersion, a polyester-type waterborne polyurethane dispersion, a polyether-type waterborne polyurethane dispersion, a polycarbonate-type waterborne polyurethane dispersion, or combinations thereof, but is not limited thereto. The SMA resin may be an SMA resin with a maleic anhydride content of 22 wt% to 42 wt%, but is not limited thereto. The cellulose acetate may be a cellulose acetate with an acetyl content of 2 wt% to 13 wt%, but is not limited thereto. The softening point of the rosin resin may be 80°C to 150°C, but is not limited thereto. The chlorine content of the chlorinated polypropylene may be 20 wt% to 40 wt%, but is not limited thereto.

Preferably, the release coating may further contain wax, but is not limited thereto. For example, the wax may be paraffin wax, polyethylene wax, polypropylene wax, or a combination thereof.

In some embodiments, the coloring coating may comprise, but is not limited to, (meth)acrylic resin, SMA resin, nitrocellulose, or combinations thereof. Specifically, the weight-average molecular weight (Mw) of the (meth)acrylic resin may be from 1,000 to 100,000, but is not limited thereto; for example, the aforementioned weight-average molecular weight may be 5,000, 8,000, 15,000, 19,000, 20,000, 22,000, 25,000, 40,000, 60,000, 80,000, or 90,000. The SMA resin may be an SMA resin with a maleic anhydride content of 22 wt% to 42 wt%, but is not limited thereto. The viscosity of the nitrocellulose may be 1/4" or 1/16", but is not limited thereto. In some embodiments, the coloring coating may further contain pigments, but is not limited thereto.

Preferably, the average thickness ratio of the release layer to the dyed layer is from 1:2.8 to 1:0.75, but is not limited thereto. More preferably, the average thickness ratio of the release layer to the dyed layer is from 1:2.5 to 1:1.33.

In some embodiments, the average thickness of the exfoliated layer can be from 0.030 μm to 0.300 μm, but is not limited thereto.

In some embodiments, the average thickness of the dye layer may be from 0.050 μm to 0.750 μm, but is not limited thereto.

In some embodiments, the transfer layer further comprises a metal layer, an adhesive layer, a laser pattern layer, or a combination thereof. Since the release layer in the transfer layer is in contact with the carrier layer, the aforementioned layers (i.e., the laser pattern layer, the metal layer, and/or the adhesive layer) may be sandwiched between the release layer and the coloring layer; alternatively, the coloring layer may be sandwiched between the release layer and at least one of the aforementioned layers, but is not limited thereto.

In some embodiments, when the transfer layer further comprises the metal layer, the metal layer may comprise aluminum (Al), copper (Cu), silver (Ag), magnesium (Mg), alloys comprising the aforementioned metals, or combinations thereof, but is not limited thereto. For example, the alloy may be an aluminum-magnesium alloy, but is not limited thereto. Furthermore, when the metal layer comprises aluminum, the metal layer may also comprise _aluminum oxide ( _Al₂O₃ ).

Because the overall thickness of the transfer layer is reduced in this invention, the transfer layer, when containing the metal layer, can appear to have a more pronounced metallic sheen. In some embodiments, the average thickness of the metal layer is approximately 8 nanometers (nm) to 500 nm, but is not limited thereto. Preferably, the average thickness of the metal layer is approximately 8 nm to 80 nm, for example, 10 nm to 35 nm.

In some embodiments, the specular gloss of the metal layer (at an incident angle of 60°) may be from 300 GU to 600 GU, but is not limited thereto. In some embodiments, the resistance of the metal layer may be from 1.0 mΩ/sq to 6.0 mΩ/sq, but is not limited thereto.

In some embodiments, when the transfer layer further includes the adhesive layer, the adhesive layer is disposed on the outermost side of the transfer layer relative to the carrier layer. Accordingly, during the transfer process, the transfer film can better adhere to the target substrate. Preferably, the adhesive layer may include a hot-melt adhesive, a thermoplastic adhesive, a radiation-curable adhesive, etc., but is not limited thereto. For example, the adhesive layer may be a polyurethane-based adhesive, a (meth)acrylate-based adhesive, a polyester-based adhesive, an epoxy-based adhesive, a vinyl acetate-based adhesive, a chlorinated polypropylene adhesive, or a combination thereof, but is not limited thereto.

In some embodiments, when the transfer layer further includes the laser pattern layer, the thickness of the laser pattern layer is extremely thin. It is usually integrated with the adjacent layers, and since the laser pattern layer mainly provides a specific optical structure, it can give the transfer film a special visual effect. It can also be applied to security and anti-counterfeiting labels or patterns, but is not limited thereto.

In some embodiments, the transfer layer may sequentially include the peel-off layer, the dye layer, the metal layer, and the bonding layer. In other embodiments, the transfer layer may sequentially include the peel-off layer, the dye layer, the laser pattern layer, the metal layer, and the bonding layer. In still other embodiments, the transfer layer may sequentially include the peel-off layer, the dye layer, the metal layer, the laser pattern layer, and the bonding layer. In yet another embodiment, the transfer layer may sequentially include the peel-off layer, the laser pattern layer, the dye layer, the metal layer, and the bonding layer.

Preferably, the 180° peel force of the transfer layer separating from the carrier layer can be from 0.8 centineutons (cN) to 3.0 cN, but is not limited thereto. More preferably, the 180° peel force of the transfer layer separating from the carrier layer can be from 1.0 cN to 2.0 cN.

Since the unevenness in the overall structure of the transfer layer may cause fluctuations in the aforementioned peeling force, preferably, the vertical amplitude of the 180° peeling force separating the transfer layer from the carrier layer is less than 0.3 cN, but is not limited thereto. More preferably, the vertical amplitude of the 180° peeling force may be less than or equal to 0.2 cN, but is not limited thereto.

Preferably, the average size of the broken powder particles on the cut end face of the transfer membrane is less than 20 μm. More preferably, the average size of the broken powder particles is less than or equal to 12 μm.

According to this invention, the transfer film can be applied to cold foil printing or hot foil stamping processes, but is not limited thereto.

In this specification, the range expressed by "decimal value to large number value" means, unless otherwise specified, that the range is greater than or equal to the decimal value and less than or equal to the large number value. For example, if the average thickness of the carrier layer is 2 micrometers to 10 micrometers, it means that the numerical range of the average thickness of the carrier layer is "greater than or equal to 2 micrometers and less than or equal to 10 micrometers".

The following illustrations illustrate the implementation of the transfer film of this invention. It should be noted that in the description of this invention, the use of terms such as "center," "upper," "lower," "top," "bottom," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the illustrations and is only for the purpose of describing this invention. It does not mean or imply that the elements referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, a specific orientation should not be understood as a limitation of this invention.

Referring to Figure 1, the transfer film 10 includes a carrier layer 11 and a transfer layer 12, with the transfer layer 12 disposed on the inner surface 111 of the carrier layer 11 and separable from the carrier layer 11. The transfer layer 12 sequentially includes a peeling layer 13 and a coloring layer 14 from top to bottom, with the peeling layer 13 in contact with the inner surface 111 of the carrier layer 11. The average thickness of the carrier layer 11 is 2 μm to 10 μm; the average thickness of the transfer layer 12 is 0.5 μm to 0.9 μm.

Referring to Figure 2, the transfer film 10 includes a carrier layer 11 and a transfer layer 12, with the transfer layer 12 disposed on the inner surface 111 of the carrier layer 11 and separable from the carrier layer 11. The transfer layer 12, from top to bottom, sequentially includes a peel layer 13, a coloring layer 14, a metal layer 15, and a bonding layer 16. That is, the peel layer 13 is in contact with the inner surface 111 of the carrier layer 11, and the bonding layer 16 is disposed on the outermost side of the transfer layer 12 opposite to the carrier layer 11. The average thickness of the carrier layer 11 is 2 μm to 10 μm; the average thickness of the transfer layer 12 is 0.5 μm to 0.9 μm.

Referring to Figure 3, the transfer film 10 includes a carrier layer 11 and a transfer layer 12, with the transfer layer 12 disposed on the inner surface 111 of the carrier layer 11 and separable from the carrier layer 11. The transfer layer 12, from top to bottom, sequentially includes a peeling layer 13, a coloring layer 14, a laser pattern layer 17, a metal layer 15, and a bonding layer 16. The peeling layer 13 is in contact with the inner surface 111 of the carrier layer 11, and the bonding layer 16 is disposed on the outermost side of the transfer layer 12 opposite to the carrier layer 11. The average thickness of the carrier layer 11 is 2 μm to 10 μm; the average thickness of the transfer layer 12 is 0.5 μm to 0.9 μm.

Referring to Figure 4, the transfer film 10 includes a carrier layer 11 and a transfer layer 12, with the transfer layer 12 disposed on the inner surface 111 of the carrier layer 11 and separable from the carrier layer 11. The transfer layer 12, from top to bottom, sequentially includes a peeling layer 13, a coloring layer 14, a metal layer 15, a laser pattern layer 17, and a bonding layer 16. The peeling layer 13 is in contact with the inner surface 111 of the carrier layer 11, and the bonding layer 16 is disposed on the outermost side of the transfer layer 12 opposite to the carrier layer 11. The average thickness of the carrier layer 11 is 2 μm to 10 μm; the average thickness of the transfer layer 12 is 0.5 μm to 0.9 μm.

In addition, several raw materials for preparing the transfer film of this invention are listed to illustrate the rheological properties of the peel layer and the coloring layer. Several embodiments are also provided to illustrate the implementation of the transfer film of this invention, and several comparative examples are provided for comparison. Those skilled in the art can easily understand the advantages and effects of this invention through the following embodiments and comparative examples. It should be understood that the embodiments listed in this specification are only used to illustrate the implementation of this invention and are not intended to limit the scope of this invention. Those skilled in the art can make various modifications and changes based on their ordinary knowledge without departing from the spirit of this invention to implement or apply the content of this invention.

Delamination

Preparation Example 1-1 : Peeling layer 1

First, the components are added to a reaction vessel to achieve the composition and corresponding amounts recorded in Table 1. Next, the components are mixed uniformly to obtain release coating A for release layer 1. Subsequently, the aforementioned release coating A is applied to the surface of an aluminum tray (parallel plate sample tray) and dried in an oven at 120°C for 1 hour, thereby forming a dried layer with a thickness of approximately 2.5 mm.

Preparation Example 1-2 : Peeling layer 2

This preparation example is similar to the preparation example 1-1 above, except that the raw material used in this preparation example (i.e., the release coating B) is not exactly the same as the release coating A in preparation example 1-1. For the specific composition, please refer to the composition and corresponding content recorded in Table 1.

Table 1 Peeling layer 1 Peeling layer 2 Release coating A solid content (parts by weight) Release coating B solids content (parts by weight) Waterborne polyurethane dispersion (without silica modification) 100 59 Waterborne polyurethane dispersion (modified with silica) -- 41 La 1 to 5 0.6 to 3 acrylic resins 5 to 10 2.9 to 6 Cellulose acetate 1 to 5 0.6 to 3

Chromogenic layer

Preparation Example 2-1 : dye layer 1

First, the components are added to a reaction vessel to achieve the composition and corresponding amounts recorded in Table 2. Next, the components are mixed uniformly to obtain the coloring coating I for the coloring layer 1. Subsequently, the aforementioned coloring coating I is applied to the surface of an aluminum disc and dried in an oven at 120°C for 1 hour, thereby forming a dried layer with a thickness of approximately 2.5 mm.

Preparation Example 2-2 : dye layer 2

This preparation example is similar to the preparation example 2-1 above, except that the raw material used in this preparation example (i.e., coloring layer coating II) is not exactly the same as the coloring layer coating I in preparation example 2-1. For the specific composition, please refer to the composition and corresponding content recorded in Table 2.

Table 2 Color layer 1 Color layer 2 Coloring Coating I Solid Content (parts by weight) Coloring Coating II Solid Content (parts by weight) Acrylic resin I (Mw is 10,000 to 20,000) 59 63 Acrylic resin II (Mw > 20,000 to 80,000) 41 37 Nitrocellulose 2.9 to 6 18.8 to 31.3 SMA resin 2.9 to 6 3.1 to 9.5

analyze 1 Rheology   

According to standard methods ASTM D4440, ASTM D4473, and ASTM D52779, a sufficient amount of dried exfoliated layer 1 was used as the test sample and placed in a 25 mm parallel plate sample tray, which was then mounted in a rheometer (manufacturer: TA Instruments, model: Discovery Hybrid). The rheometer was then heated to 80°C for 5 minutes to soften the test sample. The "conditioning sample loading" mode was then used to adjust the sample tray gap (GAP) from 0.5 µm to 1500 µm, and relevant parameters were controlled to ensure that the test sample exhibited controlled rheological behavior. After the test is completed, a new sample plate is replaced and the same procedure is repeated to obtain rheological data under different gap conditions. Similarly, the rheological properties of the release layer 2, the tinting layer 1, and the tinting layer 2 in the same manner are tested in the same way. The test results of release coating A and release coating B are shown in Figure 5, and the test results of tinting coating I and tinting coating II are shown in Figure 6. The relevant parameters of this test are recorded as follows: (1) Test frequency: 1.0 Hz; (2) Temperature range: 25°C to 180°C; (3) Heating rate: 3°C/min.

Furthermore, since the transfer film is usually separated from the release layer during the transfer process (i.e., the transfer layer is separated from the release layer) in an environment with a temperature of 25°C to 35°C, when studying the relationship between the rheological properties of the coatings that form the above layers and the release (transfer) effect, the tan δ value at 30°C is evaluated first, and the tan δ values (30°C) of release layer coating A, release layer coating B, color layer coating I, and color layer coating II are recorded in Table 3.

Table 3 Paint number Peel-off coating A Peel-off coating B Coloring layer coating I Coloring layer coating II Formation of layers Peeling layer 1 Peeling layer 2 Color layer 1 Color layer 2 tan δ value (30°C) 0.51 0.19 0.75 0.27

Transfer Membrane

The following tests were conducted on the edge trimming and transfer quality of the transfer films prepared using the layer structure shown in Figure 2 for both the embodiment and the comparative example.

Implementation Example 1 (E1)

First, the release layer coating A of Preparation Example 1-1 is applied to the inner surface 111 of a carrier film 11 and baked at a temperature of 120°C to 140°C for 6 to 8 seconds to form a release layer 13. Next, the coloring layer coating I of Preparation Example 2-1 is applied to the aforementioned release layer 13 and baked at a temperature of 130°C to 150°C for 6 to 8 seconds to form a coloring layer 14. Subsequently, a metal layer 15 is formed on the aforementioned colored layer 14 by vacuum evaporation; then, an adhesive is applied to the aforementioned metal layer 15, and it is baked at a temperature of 100°C to 120°C for 4 to 6 seconds to form an adhesion layer 16. Finally, the transfer film 10 of Embodiment 1 is obtained. That is, the transfer layer 12 in the transfer film 10 of Embodiment 1 is composed of a release layer 13, a colored layer 14, a metal layer 15 and an adhesion layer 16 stacked in sequence.

The carrier film 11 has an average thickness of about 6 µm and its material mainly includes PET; the peel layer 13 has an average thickness of about 0.075 µm; the coloring layer 14 has an average thickness of about 0.375 µm; the metal layer 15 mainly includes aluminum metal and has a resistance of about 2.5 mΩ/sq to 3.5 mΩ/sq, and the thickness of the metal layer 15 is less than 60 nm; the bonding layer 16 has an average thickness of about 0.15 µm and its material mainly includes vinyl acetate-based adhesive and chlorinated polypropylene adhesive.

Examples 2 (E2) to 11 (E11)

Following the same steps as in Example 1, transfer films of Examples 2 to 11 were prepared respectively. The main difference is that the release layer coating forming the release layer and its average thickness and/or the coloring layer coating forming the coloring layer and its average thickness are not completely the same. Detailed information is shown in Table 4.

Comparative Examples 1 (C1) to 8 (C8)

Following the same steps as in Preparation Example 1, transfer films of Comparative Examples 1 to 8 were prepared respectively. The main difference is that the release layer coating forming the release layer and its average thickness and/or the coloring layer coating forming the coloring layer and its average thickness are not completely the same. Detailed information is shown in Table 4.

Table 4 Group Peeling layer Color layer The average thickness ratio of the exfoliating layer to the dyed layer Total thickness of transfer layer (µm) Paint number Average thickness (µm) tan δ value (30°C) Paint number Average thickness (µm) tan δ value (30°C) E1 A 0.075 0.51 I 0.375 0.75 1:5 Approximately 0.60 E2 A 0.075 0.51 I 0.675 0.75 1:9 Approximately 0.90 E3 A 0.075 0.51 I 0.215 0.75 1:2.87 Approximately 0.44 E4 A 0.075 0.51 I 0.525 0.75 1:7 Approximately 0.75 E5 B 0.075 0.19 II 0.375 0.27 1:5 Approximately 0.60 E6 B 0.075 0.19 II 0.675 0.27 1:9 Approximately 0.90 E7 B 0.075 0.19 II 0.215 0.27 1:2.87 Approximately 0.44 E8 B 0.075 0.19 II 0.525 0.27 1:7 Approximately 0.75 E9 B 0.100 0.19 II 0.600 0.27 1:6 Approximately 0.85 E10 B 0.190 0.19 II 0.510 0.27 1:2.68 Approximately 0.85 E11 B 0.290 0.19 II 0.410 0.27 1:1.41 Approximately 0.85 C1 A 0.075 0.51 I 0.975 0.75 1:13 Approximately 1.20 C2 A 0.075 0.51 I 1.235 0.75 1:16.47 Approximately 1.46 C3 A 0.075 0.51 I 1.275 0.75 1:17 Approximately 1.50 C4 A 0.075 0.51 I 1.575 0.75 1:21 Approximately 1.80 C5 B 0.075 0.19 II 0.975 0.27 1:13 Approximately 1.20 C6 B 0.075 0.19 II 1.235 0.75 1:16.47 Approximately 1.46 C7 B 0.075 0.19 II 1.275 0.27 1:17 Approximately 1.50 C8 B 0.075 0.19 II 1.575 0.27 1:21 Approximately 1.80

analyze 2 : Release layer thickness, color layer thickness and total transfer layer thickness   

First, during the preparation of the transfer films in Examples 1 to 11 and Comparative Examples 1 to 8, when the release layer, the coloring layer, and the transfer film were formed in sequence, the total thickness of the current stack was measured using a shape analysis laser confocal white light interference microscope (manufacturer: KEYENCE, model: VK-X3000). Specifically, for each example/comparative example, the thickness of the release layer, the total thickness of the release layer and the coloring layer, and the total thickness of the transfer film were measured. Then, the thickness of the coloring layer was obtained by subtracting the thickness of the release layer from the total thickness of the release layer and the coloring layer. The experimental results obtained from Examples 1 to 4 and Comparative Examples 1 to 4 are recorded in Table 5-1, and the experimental results obtained from Examples 5 to 11 and Comparative Examples 5 to 8 are recorded in Table 5-2.  

analyze 3 The average size of the broken powder at the cut end of the transfer film.   

First, the transfer films of Examples 1 to 11 and Comparative Examples 1 to 8 were cut using a slitting device (pneumatic circular knife) to obtain their cut end faces as test objects. Second, each cut end face was placed on a shape analysis laser confocal white light interference microscope (manufacturer: KEYENCE, model: VK-X3000), the "laser confocal" module was selected, and the magnification was adjusted to X50. After focusing on the edge of each cut end face, measurement began. Next, the "planar measurement" mode was selected, the lead hammer baseline in the measurement tools was selected, and a horizontal line was drawn at the aforementioned edge. Then, at least five fracture points were randomly selected for measurement, and the average value of the obtained measurements was recorded in Tables 5-1 and 5-2.

Furthermore, if the average size of the broken powder is less than 12 µm, it is rated as "Excellent"; if the average size of the broken powder is greater than or equal to 12 µm and less than or equal to 15.5 µm, it is rated as "Good"; if the average size of the broken powder is greater than or equal to 15.5 µm and less than 20 µm, it is rated as "Fair"; and if the average size of the broken powder is greater than or equal to 20 µm, it is rated as "Poor".

In addition, referring to Figures 7A to 7C, taking the transfer films of Embodiment 7, Embodiment 8 and Comparative Example 2 as examples, it can be found that the broken powder generated at the edge of the cut end face of the transfer film of this invention after being cut does indeed have a smaller size.

analyze 4 : 90% Dot density   

First, the transfer films of Examples 1 to 11 and Comparative Examples 1 to 8 were subjected to the same transfer process (the adhesive layer of each transfer film was fixed onto a substrate to be heat-printed and its carrier layer was removed); then, images of each transferred layer were captured using a computer, and the images were compared with a standard using image analysis software (ImageJ); each dot in the image should be clearly distinguishable. Clear and free of foil debris; conversely, the more foil debris there is, the larger the value of the 90% dot coverage (i.e., the worse the transfer effect). Further, the 90% dot coverage of each transfer film is calculated according to formula (1), and the experimental results measured in Examples 1 to 4 and Comparative Examples 1 to 4 are recorded in Table 5-1. The experimental results measured in Examples 5 to 11 and Comparative Examples 5 to 8 are recorded in Table 5-2.  Equation (1): 90% dot coverage = foil area / normal blank area x 100%.  

Furthermore, if the 90% dot coverage rate is less than 1.0%, it is rated as "Excellent"; if the 90% dot coverage rate is greater than or equal to 1.0% and less than 2%, it is rated as "Good"; if the 90% dot coverage rate is greater than or equal to 2% and less than 4.0%, it is rated as "Fair"; and if the 90% dot coverage rate is greater than or equal to 4.0%, it is rated as "Poor".  

In addition, please refer to Figure 8. Taking the transfer films of Embodiment 3, Embodiment 4 and Comparative Example 2 as examples, it can be found that the performance of the transfer film of this invention at 90% dot coverage is significantly better than that of the transfer film of Comparative Example 2 at 90% dot coverage. Therefore, the transfer film of this invention does have better cutting performance.  

analyze 5 : Saturation and integrity rate   

Continuing with analysis 4, images of each group of transferred layers after transfer were taken with the aforementioned computer, and the images were compared with a standard product using image analysis software. The entire area in the aforementioned image should be completely covered with black dots and without any white showing. Therefore, the more white showing (i.e., missing heat), the lower the value of the fullness and integrity rate. Further, the fullness and integrity rate of each group of transfer films was calculated according to formula (2), and the experimental results measured in Examples 1 to 4 and Comparative Examples 1 to 4 were recorded in Table 5-1. The experimental results measured in Examples 5 to 11 and Comparative Examples 5 to 8 were recorded in Table 5-2. Formula (2): Fullness and integrity rate = 100% - (Area of missing hot spots / Total area) x 100%.  

Furthermore, if the fullness and integrity rate is greater than or equal to 99%, it is rated as "Excellent"; if the fullness and integrity rate is less than 99% but greater than or equal to 96%, it is rated as "Good"; if the fullness and integrity rate is less than 96% but greater than or equal to 92%, it is rated as "Fair"; and if the fullness and integrity rate is less than 92%, it is rated as "Poor".  

analyze 6 : 70% Outlet hot rate   

Continuing with analysis 4, images of each group of transferred layers after transfer were captured using the aforementioned computer, and the images were compared with a standard using image analysis software (ImageJ). Each dot in the aforementioned image should be a complete dot. However, the higher the incompleteness of the dots, the more severe the heat loss (i.e., the larger the heat loss rate). Further, the 70% dot heat loss rate of each group of transfer films was calculated according to formula (3), and the experimental results measured in Examples 1 to 4 and Comparative Examples 1 to 4 were recorded in Table 5-1. The experimental results measured in Examples 5 to 11 and Comparative Examples 5 to 8 were recorded in Table 5-2. Formula (3): 70% black dot defect rate = Black dot defect area / Normal complete black dot area x 100%.

Furthermore, if the rate of missing hot pot at 70% of outlets is less than 0.85%, it is rated as "Excellent"; if the rate of missing hot pot at 70% of outlets is greater than or equal to 0.85% but less than 2%, it is rated as "Good"; if the rate of missing hot pot at 70% of outlets is greater than or equal to 2% but less than 3.0%, it is rated as "Fair"; and if the rate of missing hot pot at 70% of outlets is greater than or equal to 3.0%, it is rated as "Poor".

Table 5-1   Group Total thickness of transfer layer (µm) Average size of broken powder fragments (µm) 90% of the dots were filled with ink. Saturation and integrity rate 70% of outlets are out of service E1 Approximately 0.60 8.0 2.0% -- -- E2 Approximately 0.90 10.0 3.0% -- -- E3 Approximately 0.44 6.0 0.0% 95.16% 0.0% E4 Approximately 0.75 8.0 1.4% 99.85% 0.0% C1 Approximately 1.20 12.0 4.0% -- -- C2 Approximately 1.46 13.0 5.7% 100% 0.0% C3 Approximately 1.50 14.0 5.0% -- -- C4 Approximately 1.80 16.0 6.0% -- -- Table 5-2 Group Total thickness of transfer layer (µm) Average size of broken powder fragments (µm) 90% of the dots were filled with ink. Saturation and integrity rate 70% of outlets are out of service E5 Approximately 0.60 16.0 0.1% -- -- E6 Approximately 0.90 18.0 0.5% -- -- E7 Approximately 0.44 9.0 0.0% 86.62% 11.99% E8 Approximately 0.75 10.0 0.0% 87.31% 4.93% E9 Approximately 0.85 10.0 0.0% 94.52% 3.41% E10 Approximately 0.85 10.0 0.8% 96.88% 0.0% E11 Approximately 0.85 9.0 3.8% 100.0% 0.0% C5 Approximately 1.20 20.0 1.0% -- -- C6 Approximately 1.46 20.0 1.1% 98.87% 0.0% C7 Approximately 1.50 22.0 1.5% -- -- C8 Approximately 1.80 24.0 2.0% -- --

Discussion of experimental results

The analysis results in Tables 5-1 and 5-2 show that, after cutting, the fractured powder on the cut edges of the transfer films of Examples 1 to 11 is less than 20 μm, and the dot jamming rate of the transfer films of Examples 1 to 11 after hot stamping is less than 4%. This proves that the transfer film created in this invention can indeed have good edge trimming properties and printing quality, thereby reducing material consumption, carbon emissions, and energy consumption.

Furthermore, from the analysis results of Examples 1 and 5, it can be seen that even if the total thickness of the transfer layer is the same, when the rheological tan δ value (30°C) of the release layer and/or the dyeing layer is higher, the average size of the broken powder on the cut end face of the transfer film is smaller after cutting. Similarly, the comparison of the analysis results of Examples 2 and 6, Examples 3 and 7, Examples 4 and 8, etc., all show the same trend.

Furthermore, a comparison of the analysis results 5 and 6 of Examples 3 and 7 shows that even with the same total thickness of the transfer layer, when the rheological properties tan δ (30°C) of the release layer coating are 0.35 to 0.8 and the rheological properties tan δ (30°C) of the coloring layer coating are 0.4 to 0.97, the transfer film has better saturation integrity and a lower 70% dot defect rate, indicating that the transfer film has better edge cutting properties and hot stamping performance.

Furthermore, a comparison of the analysis results of the transfer films from Examples 9 to 11 shows that even if the total thickness of the transfer layers is the same, when the average thickness ratio of the release layer to the dyeing layer is in the range of 1:2.8 to 1:1.33, better fullness and integrity and a lower 70% dot defect rate can be achieved.

Furthermore, by comparing the average size of the broken powder particles in Examples 1 to 4 and Comparative Examples 1 to 4 in Table 5-1, it can be seen that the larger the total thickness of the transfer layer, the larger the size of the broken powder particles generated at the edge of its cut surface.

In summary, this invention, by controlling the average thickness range of the carrier layer and the transfer layer comprising the release layer and the coloring layer, helps to reduce the size of broken dust particles generated at the cut edge of the transfer film during cutting, thereby reducing material consumption and improving cost-effectiveness. Furthermore, due to the improved cutability, it also exhibits better dot packing rate, enhancing the transfer quality. In addition, the transfer film of this invention, by reducing the overall thickness of the transfer layer, can reduce the amount of organic coatings and solvents used, offering a clear cost advantage and environmental friendliness, thus enhancing the application value of this invention and meeting the expectations of modern corporate sustainability.

The above embodiments are merely examples for illustrative purposes. The scope of the rights claimed in this work shall be based on the contents of the patent application, and not limited to the above embodiments.

10: Transfer film; 11: Carrier layer; 111: Inner surface; 12: Transfer layer; 13: Peel layer; 14: Coloring layer; 15: Metal layer; 16: Adhesive layer; 17: Laser pattern layer.

Figure 1 is a schematic side view of the first embodiment of the transfer film of the present invention. Figure 2 is a schematic side view of the second embodiment of the transfer film of the present invention. Figure 3 is a schematic side view of the third embodiment of the transfer film of the present invention. Figure 4 is a schematic side view of the fourth embodiment of the transfer film of the present invention. Figure 5 shows the rheological test results of release coating A and release coating B. Figure 6 shows the rheological test results of color coating I and color coating II. Figures 7A to 7C are, in order, images of the cut ends of Embodiment 7, Embodiment 8 and Comparative Example 2 in Analysis 3. Figure 8 shows the heat transfer results (90%, 80%, and 70% dots) of the transfer films of Examples 3, 4, and 2.

without

10: Transfer membrane

11: Carrier Layer

111: Inner surface

12: Transfer Layer

13: Delamination

14: Color layer

Claims (12)

A transfer film includes: a carrier layer; and a transfer layer disposed on the inner surface of the carrier layer and detachable from the carrier layer; wherein the transfer layer includes a release layer and a coloring layer, the release layer being in contact with the inner surface of the carrier layer; wherein the average thickness of the carrier layer is 2 micrometers to 10 micrometers; and the average thickness of the transfer layer is 0.5 micrometers to 0.9 micrometers. The transfer film as described in claim 1, wherein at least one of the release layer coating forming the release layer and the coloring layer coating forming the coloring layer has a rheological tan δ value (30°C) of 0.1 to 1. The transfer film as described in claim 2, wherein the rheological tan δ values (30°C) of the release layer coating and the coloring layer coating are each independently 0.1 to 1. The transfer film as described in claim 1, wherein the 180° peel force of the transfer layer separating from the carrier layer is 0.8 centineutons to 3.0 centineutons. The transfer film as described in claim 4, wherein the vertical amplitude of the 180° peeling force on which the transfer layer separates from the carrier layer is less than 0.3 cN. The transfer film as described in any one of claims 1 to 5, wherein the average thickness ratio of the peeling layer to the dyeing layer is from 1:2.8 to 1:0.75. The transfer film as described in claim 6, wherein the average thickness ratio of the peeling layer to the dyeing layer is from 1:2.5 to 1:1.33. The transfer film as described in any one of claims 1 to 5, wherein the transfer layer further comprises a metal layer, an adhesive layer, a laser pattern layer, or a combination thereof; the adhesive layer is disposed on the outermost side of the transfer layer opposite to the carrier layer; the metal layer comprises aluminum, copper, silver, magnesium, an alloy comprising the aforementioned metals, or a combination thereof. The transfer film as described in claim 8, wherein the transfer layer sequentially comprises the release layer, the coloring layer, the metal layer and the bonding layer. The transfer film as described in claim 2 or 3, wherein the release coating comprises (meth)acrylate resin, polyurethane dispersion, styrene-maleic anhydride copolymer resin, cellulose acetate, rosin resin, chlorinated polypropylene, polycarbonate, or combinations thereof. The transfer membrane as described in any one of claims 1 to 5, wherein the material of the carrier layer comprises polyethylene terephthalate, polyethylene, polystyrene, polyimide, polylactic acid, polybutylene succinate, polyacrylonitrile, polyurethane, polycarbonate, polyvinyl chloride, glass, stone paper, or combinations thereof. The transfer membrane as described in any of claims 1 to 5, wherein the average size of the broken powder particles at the cut end face of the transfer membrane is less than 20 micrometers.