Transfer hot melt adhesive film, its preparation method and application

Abstract

This application relates to a transfer hot melt adhesive film, its preparation method, and its application. The transfer hot melt adhesive film includes a hot melt adhesive layer, a high-temperature resistant layer, and a silicone adhesive layer stacked sequentially. This application employs a three-layer structure, successfully avoiding the limitation that silicone is not easily adhered to by hot melt adhesive, and preventing problems such as silicone layer peeling and delamination.

Description

Technical Field

[0001] This application relates to the field of heat transfer materials, and in particular to a heat transfer hot melt adhesive film, its preparation method, and its application. Background Technology

[0002] The application of heat transfer technology in trademarks has greatly promoted production flexibility and shortened delivery time. In particular, silicone products have advantages such as good feel and durability, and can be widely used in various daily necessities.

[0003] In the process of using transfer labels, adhesives are used to adhere to the surface of the product. For products that need to be washed or used outdoors, the adhesion of pressure-sensitive adhesives is difficult to meet the requirements under humid and hot conditions. Hot melt adhesives have good adhesion, but in the transfer process, hot melt adhesives need to be melted into a liquid state to effectively adhere to the surface of the product. However, liquid hot melt adhesives are difficult to completely wet the silicone surface and cannot adhere firmly, resulting in peeling and delamination. Summary of the Invention

[0004] Therefore, it is necessary to provide a transfer hot melt adhesive film, its preparation method and application, to solve the problems of peeling and delamination that occur during silicone transfer.

[0005] In a first aspect, this application provides a transfer hot melt adhesive film, which includes a hot melt adhesive layer, a high-temperature resistant layer and a silicone adhesive layer stacked sequentially.

[0006] In some embodiments, the material of the silicone adhesive layer includes a carbon chain compound containing an olefin group, or a modified siloxane;

[0007] Optionally, the olefin-containing carbon chain compound includes at least one of the following: polyurethane containing vinyl segments, acrylate containing vinyl segments, polyester compound containing vinyl segments, polyurethane containing butadiene segments, acrylate containing butadiene segments, and polyester compound containing butadiene segments.

[0008] Optionally, the modified siloxane is a modified siloxane containing at least one of hydroxyl, epoxy, and olefin groups.

[0009] In some embodiments, the thickness of the silicone adhesive layer is 0.01 to 0.10 mm, for example, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm or 0.10 mm.

[0010] In some embodiments, the material of the high-temperature resistant layer includes at least one of polyurethane, acrylate, and polyester compounds.

[0011] In some embodiments, the melting point of the high-temperature resistant layer is greater than the melting point of the hot melt adhesive layer.

[0012] In some embodiments, the hardness of the high-temperature resistant layer is 50 to 100A, for example, 50A, 55A, 60A, 65A, 70A, 75A, 80A, 85A, 90A, 95A or 100A.

[0013] In some embodiments, the thickness of the high-temperature resistant layer is 0.02 to 0.10 mm, for example, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm or 0.10 mm.

[0014] In some embodiments, the material of the hot melt adhesive layer includes at least one of thermoplastic polyurethane, acrylate, polyester compound, and ethylene-vinyl acetate copolymer.

[0015] Optionally, the melting point of the hot melt adhesive layer is 60 to 150°C, for example, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C.

[0016] In some embodiments, the hardness of the hot melt adhesive layer is 50 to 100A, for example, 50A, 55A, 60A, 65A, 70A, 75A, 80A, 85A, 90A, 95A or 100A.

[0017] In some embodiments, the thickness of the hot melt adhesive layer is 0.08 to 0.20 mm, for example, 0.08 mm, 0.09 mm, 0.10 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm or 0.20 mm.

[0018] In some embodiments, the hot melt adhesive layer is prepared from at least two raw materials with different melting points.

[0019] Optionally, the hot melt adhesive layer is made of a first thermoplastic polyurethane and a second thermoplastic polyurethane, wherein the melting point of the first thermoplastic polyurethane is lower than that of the second thermoplastic polyurethane.

[0020] Optionally, the melting point of the first polyurethane is 60–100°C.

[0021] Optionally, the melting point of the second polyurethane is 120–150°C.

[0022] In some embodiments, the hot melt adhesive layer is prepared by melt casting, and the raw material composition of the hot melt adhesive layer is as follows, according to parts by mass:

[0023] First thermoplastic polyurethane: 19.8–44 parts;

[0024] 45-75 parts of the second thermoplastic polyurethane.

[0025] Optionally, the raw materials of the hot melt adhesive layer further include a co-solvent, an antioxidant, and an ultraviolet absorber. The raw material composition of the hot melt adhesive layer, by weight, is as follows:

[0026]

[0027]

[0028] In some embodiments, the hot melt adhesive layer is prepared by solution coating, and the raw material composition of the hot melt adhesive layer is as follows, according to parts by mass:

[0029] 6-13 parts of the first thermoplastic polyurethane;

[0030] 14–27 parts of the second thermoplastic polyurethane;

[0031] Solvent: 66.7–78.4 parts.

[0032] Optionally, the raw materials of the hot melt adhesive layer further include a co-solvent, an antioxidant, and an ultraviolet absorber. The raw material composition of the hot melt adhesive layer, by weight, is as follows:

[0033]

[0034] Secondly, this application provides a method for preparing a transfer hot melt adhesive film as described in the first aspect, the method comprising:

[0035] Hot melt adhesive material is mixed with an additive solution to obtain a hot melt adhesive slurry, and a hot melt adhesive layer is prepared using the hot melt adhesive slurry.

[0036] A high-temperature resistant layer and a silicone adhesive layer are sequentially deposited on the surface of the hot melt adhesive layer to prepare the transfer hot melt adhesive film.

[0037] In some embodiments, the hot melt adhesive layer is formed by melt casting or solution coating.

[0038] In some embodiments, the hot melt adhesive layer is formed by melt casting, which includes mixing hot melt adhesive material with an additive solution, and then sequentially melting, granulating and casting to form a hot melt adhesive layer.

[0039] In some embodiments, the hot melt adhesive layer is formed by a solution coating method, which includes: mixing hot melt adhesive material, additive solution and solvent to obtain hot melt adhesive slurry, and coating to form a hot melt adhesive layer.

[0040] In some embodiments, the adjuvant solution also includes antioxidants and ultraviolet absorbers.

[0041] In some embodiments, the high-temperature resistant layer is formed by screen printing or coating, and the silicone adhesive layer is formed by screen printing or coating.

[0042] Thirdly, this application provides an application of the transfer hot melt adhesive film as described in the first aspect, wherein the transfer hot melt adhesive film is applied to silicone transfer.

[0043] The numerical range described in this application includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0044] This application has the following beneficial effects:

[0045] The transfer hot melt adhesive film in this application has a three-layer structure. The silicone adhesive layer is a transition layer that connects the silicone of the silicone-based polymer compound and the high-temperature resistant layer of the carbon-based polymer compound. The high-temperature resistant layer can maintain solid properties during the transfer process, avoiding the cohesive force when the hot melt adhesive cools and solidifies, as well as the deformation and rebound of the silicone after pressure relief, which would cause the hot melt adhesive to peel off and delaminate from the silicone. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the transfer hot melt adhesive film in some embodiments of this application.

[0047] Figure 2 This is a schematic diagram illustrating the application of transfer hot melt adhesive film in some embodiments of this application.

[0048] 100 - Transfer hot melt adhesive film; 110 - Hot melt adhesive layer; 120 - High temperature resistant layer; 130 - Silicone adhesive layer; 200 - Release paper; 300 - Silicone layer; 400 - Attached substrate. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0051] Traditional silicone transfer hot melt adhesive films, whether grafted or with a transition layer structure, suffer from interlayer compatibility issues between carbon-based and silicon-based materials. Furthermore, during the transfer process, high temperatures lead to poor compatibility between the liquid hot melt adhesive and solid silicone. After cooling, the cohesive force of the hot melt adhesive and the elasticity of the silicone after pressure relief cause the hot melt adhesive to peel off and delaminate from the silicone. Therefore, a transfer hot melt adhesive film is needed to solve the peeling and delamination problems.

[0052] The first aspect of this application provides a transfer hot melt adhesive film, which includes a hot melt adhesive layer, a high-temperature resistant layer, and a silicone adhesive layer stacked sequentially. For example... Figure 1 As shown, the hot melt adhesive film 100 is disposed on the release paper 200, and a hot melt adhesive layer 110, a high temperature resistant layer 120 and a silicone adhesive layer 130 are sequentially stacked on the surface of the release paper 200.

[0053] In this application, a high-temperature resistant layer is provided between the hot melt adhesive layer and the silicone adhesive layer. The high-temperature resistant layer can maintain its solid properties during the transfer process, providing a stable contact interface for the hot melt adhesive layer and the silicone adhesive layer, thereby improving the interlayer stability. Moreover, the silicone adhesive layer has good compatibility with silicone, which improves the adhesion between the hot melt adhesive film and the silicone.

[0054] In some embodiments, the material of the silicone adhesive layer includes a carbon chain compound containing an olefin group, or a modified siloxane.

[0055] This application uses carbon chain compounds containing olefin groups or modified siloxanes as silicone adhesives, which are compatible with both the high-temperature resistant layer and the silicone layer, thereby improving the adhesion between the silicone adhesive layer and the high-temperature resistant layer and the silicone layer.

[0056] Optionally, the olefin-containing carbon chain compound includes at least one of polyurethane containing vinyl segments, acrylate containing vinyl segments, polyester compound containing vinyl segments, polyurethane containing butadiene segments, acrylate containing butadiene segments, and polyester compound containing butadiene segments. For example, the polyester compound containing vinyl segments includes vinyl polycarbonate.

[0057] The silicone adhesive layer of this application uses a carbon chain compound containing olefin groups. The double bonds in the olefin groups can undergo addition polymerization with the silanyl hydrogen in the silicone, thereby forming a strong chemical bond between the silicone adhesive layer and the silicone, improving the adhesion between the silicone adhesive layer and the silicone. Moreover, the carbon-based segments have good compatibility with the high-temperature resistant layer, allowing them to penetrate into the high-temperature resistant layer and improve the adhesion between the silicone adhesive layer and the high-temperature resistant layer.

[0058] Optionally, the modified siloxane is a modified siloxane containing at least one of hydroxyl, epoxy, and olefin groups.

[0059] In this application, the silicone adhesive layer uses modified siloxane. Firstly, siloxane has good compatibility with silicone, which can enhance the physical force formed by the penetration and entanglement between the silicone adhesive and silicone. At the same time, the olefin groups in the modified silane can also form chemical bonds with the excess silanyl hydrogen in the silicone during the silicone vulcanization process. Moreover, the grafted hydroxyl and epoxy groups can be compatible with, penetrate, and form chemical bonds with the high-temperature resistant layer. Thus, the silicone adhesive layer is a transition layer connecting the silicone and the high-temperature resistant layer, effectively ensuring the stability and adhesion of the hot melt adhesive film.

[0060] In some embodiments, the thickness of the silicone adhesive layer is 0.01 to 0.10 mm.

[0061] In some embodiments, the modified siloxane is preferably a modified siloxane having hydroxyl and olefin groups, a modified siloxane having epoxy and olefin groups, or a modified siloxane having hydroxyl, epoxy, and olefin groups. Based on the mechanical strength of the silicone adhesive layer, the thickness of the silicone adhesive layer is preferably 0.02 to 0.05 mm.

[0062] In some embodiments, the material of the high-temperature resistant layer includes at least one of polyurethane, acrylate and polyester compounds, such as polycarbonate.

[0063] In some embodiments, the melting point of the high-temperature resistant layer is greater than the melting point of the hot melt adhesive layer. In this application, no specific requirements or special limitations are made for the melting point of the high-temperature resistant layer. Those skilled in the art can make reasonable selections based on actual usage requirements. Optionally, based on the garment washing requirements of the apparel industry, the melting point of the high-temperature resistant layer is greater than 150°C.

[0064] In this application, the melting point of the high-temperature resistant layer is higher than that of the hot melt adhesive layer, and the temperature during transfer does not exceed the melting point of the high-temperature resistant layer, ensuring its solid properties during the transfer process. Therefore, during the transfer process, the high-temperature resistant layer, the silicone adhesive layer, and the silicone layer all remain solid, guaranteeing the stability between them. Furthermore, the material selection for the high-temperature resistant layer is similar to that of the hot melt adhesive material to ensure good compatibility between the two layers. The high-temperature resistant layer also provides a stable carbon-based contact surface for the hot melt adhesive layer, ensuring effective adhesion between them.

[0065] In some embodiments, the hardness of the high-temperature resistant layer is 50–100A, preferably 60–80A, and the thickness of the high-temperature resistant layer is 0.02–0.10 mm. The hardness and thickness of the high-temperature resistant layer are selected in this application to facilitate mold cutting.

[0066] In some embodiments, the hot melt adhesive layer is made of at least one of thermoplastic polyurethane, acrylate, polyester compounds, and ethylene-vinyl acetate copolymer. Optionally, based on the garment washing requirements of the apparel industry, a hydrolysis-resistant thermoplastic polyurethane is selected, and correspondingly, a polyurethane material with a higher melting point is selected for the high-temperature resistant layer to ensure good compatibility between the high-temperature resistant layer and the hot melt adhesive.

[0067] In some embodiments, the melting point of the hot melt adhesive layer is 60–150°C; the hardness of the hot melt adhesive layer is 50–100A, preferably 60–80A; and the thickness of the hot melt adhesive layer is 0.08–0.20 mm, preferably 0.10–0.15 mm.

[0068] In some embodiments, the hot melt adhesive layer is prepared from at least two raw materials with different melting points. In this application, hot melt adhesive raw materials with different melting points are mixed to create a significant gradient in the process of the hot melt adhesive changing from a liquid to a solid state. This ensures that the cooling and curing of the hot melt adhesive is a slow process, achieving gradual curing. This facilitates the release of cohesive forces during the cooling and curing process, reduces the degree of hot melt adhesive shrinkage, and prevents peeling between adhesive film layers and curling around the edges of the adhesive film.

[0069] In some embodiments, based on the temperature during garment washing and drying, hot melt adhesives with high, medium, and low melting points are mixed to form a gradient range of 60–150°C, wherein the peak value of the component content is between 120–140°C.

[0070] In some embodiments, the hot melt adhesive layer is prepared from a first thermoplastic polyurethane and a second thermoplastic polyurethane, wherein the melting point of the first thermoplastic polyurethane is lower than that of the second thermoplastic polyurethane.

[0071] Optionally, the melting point of the first polyurethane is 60-100°C, and the melting point of the second polyurethane is 120-150°C.

[0072] In some embodiments, the hot melt adhesive layer is prepared by melt casting, and the raw material composition of the hot melt adhesive layer is as follows, according to parts by mass:

[0073] First thermoplastic polyurethane: 19.8–44 parts;

[0074] 45-75 parts of the second thermoplastic polyurethane.

[0075] In some embodiments, the raw materials of the hot melt adhesive layer further include a cosolvent, an antioxidant, and an ultraviolet absorber. The raw material composition of the hot melt adhesive layer, by weight, is as follows:

[0076]

[0077]

[0078] In some embodiments, the hot melt adhesive layer is prepared by solution coating, and the raw material composition of the hot melt adhesive layer is as follows, according to parts by weight:

[0079] 6-13 parts of the first thermoplastic polyurethane;

[0080] 14–27 parts of the second thermoplastic polyurethane;

[0081] Solvent: 66.7–78.4 parts.

[0082] Optionally, the raw materials of the hot melt adhesive layer further include a co-solvent, an antioxidant, and an ultraviolet absorber. The raw material composition of the hot melt adhesive layer, by weight, is as follows:

[0083]

[0084] In some embodiments, the solvent includes at least one of N,N-dimethylformamide (DMF), isopropanol, and butanone.

[0085] In some embodiments, the co-solvent includes at least one of acetone, ethyl acetate, isopropanol, and butanone.

[0086] In some embodiments, the antioxidant includes at least one of antioxidant 1076, antioxidant 1010, and antioxidant 164.

[0087] In some embodiments, the ultraviolet absorber includes benzophenones and / or benzotriazoles, for example, benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone.

[0088] A second aspect of this application provides a method for preparing a transfer hot melt adhesive film as described in the first aspect, the method comprising:

[0089] Hot melt adhesive material is mixed with an additive solution to obtain a hot melt adhesive slurry, and a hot melt adhesive layer is prepared using the hot melt adhesive slurry.

[0090] A high-temperature resistant layer and a silicone adhesive layer are sequentially deposited on the surface of the hot melt adhesive layer to prepare the transfer hot melt adhesive film.

[0091] In the process of preparing the three-layer transfer hot melt adhesive film in this application, although the number of coating times is increased, the thickness of the silicone adhesive layer and the high temperature resistant layer is low, the coating efficiency is high, the drying speed is fast, and the preparation cost and efficiency are basically the same as those of the hot melt adhesive film in the traditional technology.

[0092] In some embodiments, the hot melt adhesive layer is formed by melt casting, which includes: mixing hot melt adhesive material with an additive solution, and then sequentially melting, granulating and casting into a film.

[0093] In some embodiments, the hot melt adhesive layer is formed by a solution coating method, which includes: mixing hot melt adhesive material, an additive solution, and a solvent to obtain a hot melt adhesive slurry, and then coating it to form a hot melt adhesive layer. Optionally, during the coating process, the wet film thickness is 0.05–0.15 mm each time, and during the drying process, the drying temperature is 60–100°C, and the drying time is 3–10 min.

[0094] In some embodiments, the adjuvant solution further includes antioxidants and ultraviolet absorbers.

[0095] In some embodiments, the high-temperature resistant layer is formed by screen printing or coating, and the silicone adhesive layer is formed by screen printing or coating.

[0096] In some embodiments, the drying temperature of the high-temperature resistant layer coating step is 60–100°C, and the drying time is 3–10 min.

[0097] In some embodiments, during the coating process of the silicone adhesive layer, the wet film thickness is 0.01 to 0.03 mm each time, and during the drying process, the drying temperature is 80 to 120°C and the drying time is 3 to 10 minutes.

[0098] According to one specific embodiment, the method for preparing the transfer hot melt adhesive film includes the following steps:

[0099] 1) Mix the antioxidant, ultraviolet absorber and cosolvent in a certain proportion to form an auxiliary agent solution;

[0100] 2) Preparation of hot melt adhesive layer by melt casting method: After mixing the various hot melt adhesive components and additive solutions, the mixture is sequentially melted, granulated, and cast to form a hot melt adhesive layer; or,

[0101] Solution coating method for preparing hot melt adhesive layer: Mix the hot melt adhesive components, solvent and additive solution to obtain a mixed slurry. Coat the mixed slurry with a wet film thickness of about 0.05-0.15 mm each time. After coating, bake at 60-100℃ for 3-10 minutes to form hot melt adhesive layer.

[0102] 3) A high-temperature resistant layer is formed by screen printing or coating on the hot melt adhesive layer;

[0103] 4) A silicone adhesive layer is formed by screen printing or coating on the high-temperature resistant layer.

[0104] A third aspect of this application provides an application of the transfer hot melt adhesive film as described in the first aspect, wherein the transfer hot melt adhesive film is used for silicone transfer. Figure 2 As shown, the transfer hot melt adhesive film 100 is disposed between the substrate 400 and the silicone layer 300, bonding the silicone layer 300 to the surface of the substrate 400. From the substrate 400 to the silicone layer 300, the transfer hot melt adhesive film 100 sequentially includes a hot melt adhesive layer 110, a high-temperature resistant layer 120, and a silicone adhesive layer 130.

[0105] Optionally, the thickness of the silicone layer is ≥2mm.

[0106] Optionally, the line width in the silicone layer is ≤1mm.

[0107] The raw materials used in the following examples are as follows:

[0108] The first thermoplastic polyurethane was purchased from Huafeng Group, with the grade HF-3H95SL, a melting point of 80℃, and a hardness of 90A.

[0109] The second thermoplastic polyurethane was purchased from Huafeng Group, with the grade HF-3H80AL, a melting point of 135℃, and a hardness of 75A.

[0110] The high-temperature resistant layer is made of solvent-based polyurethane, which was purchased from Qingyuan Fanyi Polyurethane Co., Ltd., with the brand name GS-3055M. This polyurethane is unmodified.

[0111] The silicone adhesive layer is prepared using a silicone adhesive purchased from Huizhou Yirun Organosilicon Co., Ltd., with the brand name XG-360Z-3. This silicone adhesive is a modified siloxane containing hydroxyl groups.

[0112] Example 1

[0113] 1) Weigh the raw materials according to their mass percentages, as follows:

[0114]

[0115] First, mix antioxidant 1076, ultraviolet absorber 2,4-dihydroxybenzophenone and cosolvent acetone in a certain proportion to form an auxiliary agent solution, and set it aside for later use;

[0116] 2) After completely dissolving HF-3H95SL and HF-3H80AL in methyl ethyl ketone, add the additive solution and stir evenly to obtain a hot melt adhesive slurry. Coat the hot melt adhesive slurry onto the release paper with a wet film thickness of 0.1 mm each time and bake at 80°C for 3 minutes. Coat twice to form a hot melt adhesive layer with a dry film thickness of 0.1 mm.

[0117] 3) After the hot melt adhesive layer is dried, a solvent-based polyurethane GS-3055M is coated on the surface of the hot melt adhesive layer with a wet film thickness of 0.1 mm. It is then baked at 100°C for 3 minutes to form a high-temperature resistant layer with a dry film thickness of 0.02 mm.

[0118] 4) After the high-temperature resistant layer is dried, a silicone adhesive XG-360Z-3 solution is coated on the surface of the high-temperature resistant layer. The wet film thickness is 0.03 mm. The film is then baked at 100°C for 10 minutes to form a silicone adhesive layer with a dry film thickness of 0.02 mm, thus preparing the transfer hot melt adhesive film.

[0119] Example 2

[0120] 1) Weigh the raw materials according to their mass percentages, as follows:

[0121]

[0122] The above raw materials are mixed and then granulated using a screw extruder to obtain thermoplastic polyurethane granules;

[0123] 2) Thermoplastic polyurethane granules are cast onto release paper using a casting machine to form a hot melt adhesive layer with a thickness of 0.1 mm;

[0124] 3) Apply solvent-based polyurethane GS-3055M to the surface of the hot melt adhesive layer, with a wet film thickness of 0.1 mm, and bake at 100°C for 3 minutes to form a high-temperature resistant layer with a dry film thickness of 0.02 mm.

[0125] 4) After the high-temperature resistant layer is dried, a silicone adhesive XG-360Z-3 solution is coated on the surface of the high-temperature resistant layer. The wet film thickness is 0.03 mm. The film is then baked at 100°C for 10 minutes to form a silicone adhesive layer with a dry film thickness of 0.02 mm, thus preparing the transfer hot melt adhesive film.

[0126] Example 3

[0127] 1) Weigh the raw materials according to their mass percentages, as follows:

[0128]

[0129] First, mix antioxidant 1076, ultraviolet absorber 2,4-dihydroxybenzophenone and cosolvent acetone in a certain proportion to form an auxiliary agent solution, and set it aside for later use;

[0130] 2) After completely dissolving HF-3H95SL and HF-3H80AL in methyl ethyl ketone, add the additive solution and stir evenly to obtain a hot melt adhesive slurry. Coat the hot melt adhesive slurry onto the release paper with a wet film thickness of 0.1 mm each time and bake at 80°C for 3 minutes. Coat 3 times to form a hot melt adhesive layer with a dry film thickness of 0.15 mm.

[0131] 3) After the hot melt adhesive layer dries, apply solvent-based polyurethane GS-3055M to the surface of the hot melt adhesive layer. The wet film thickness is 0.1mm. Bake at 100℃ for 3 minutes. Apply 5 times to form a high-temperature resistant layer with a dry film thickness of 0.10mm.

[0132] 4) After the high-temperature resistant layer is dried, a silicone adhesive XG-360Z-3 solution is coated on the surface of the high-temperature resistant layer. The wet film thickness is 0.03 mm. The layer is baked at 100°C for 10 minutes. The coating is applied twice to form a silicone adhesive layer with a dry film thickness of 0.05 mm, thus preparing the transfer hot melt adhesive film.

[0133] Example 4

[0134] 1) Weigh the raw materials according to their mass percentages, as follows:

[0135]

[0136] The above raw materials are mixed and then granulated using a screw extruder to obtain thermoplastic polyurethane granules;

[0137] 2) Thermoplastic polyurethane granules are cast onto release paper using a casting machine to form a hot melt adhesive layer with a thickness of 0.15 mm;

[0138] 3) Apply solvent-based polyurethane GS-3055M to the surface of the hot melt adhesive layer, with a wet film thickness of 0.1 mm. Bake at 100°C for 3 minutes, apply twice, to form a high-temperature resistant layer with a dry film thickness of 0.04 mm.

[0139] 4) After the high-temperature resistant layer is dried, a silicone adhesive XG-360Z-3 solution is coated on the surface of the high-temperature resistant layer. The wet film thickness is 0.03 mm. The layer is baked at 100°C for 10 minutes and coated 5 times to form a silicone adhesive layer with a dry film thickness of 0.10 mm, thus preparing the transfer hot melt adhesive film.

[0140] Example 5

[0141] The transfer hot melt adhesive film was prepared according to the preparation method of Example 1, except that HF-3H95SL was adjusted to be of the same mass as HF-3H80AL.

[0142] Comparative Example 1

[0143] 1) Weigh the raw materials according to their mass percentages, as follows:

[0144]

[0145] First, mix antioxidant 1076, ultraviolet absorber 2,4-dihydroxybenzophenone and cosolvent acetone in a certain proportion to form an auxiliary agent solution, and set it aside for later use;

[0146] 2) After completely dissolving HF-3H95SL and HF-3H80AL in methyl ethyl ketone, add the additive solution and stir evenly to obtain a hot melt adhesive slurry. Coat the hot melt adhesive slurry onto the release paper with a wet film thickness of 0.1 mm each time and bake at 80°C for 3 minutes. Coat twice to form a hot melt adhesive layer with a dry film thickness of 0.1 mm.

[0147] 3) After the hot melt adhesive layer is dried, a silicone adhesive solution is coated on the surface of the hot melt adhesive layer with a wet film thickness of 0.03 mm. The film is then baked at 100°C for 10 minutes to form a silicone adhesive layer with a dry film thickness of 0.02 mm, thus preparing the transfer hot melt adhesive film.

[0148] Comparative Example 2

[0149] 1) Weigh the raw materials according to their mass percentages, as follows:

[0150]

[0151] The above raw materials are mixed and then granulated using a screw extruder to obtain thermoplastic polyurethane granules;

[0152] 2) Thermoplastic polyurethane granules are cast onto release paper using a casting machine to form a hot melt adhesive layer with a thickness of 0.1 mm;

[0153] 3) Coat the surface of the hot melt adhesive layer with a silicone adhesive solution, the wet film thickness is 0.03 mm, and bake at 100°C for 10 minutes to form a silicone adhesive layer with a dry film thickness of 0.02 mm, thus preparing the transfer hot melt adhesive film.

[0154] Test case

[0155] The prepared mold silicone paste is placed in the mold, and the side of the hot melt transfer adhesive film with the silicone adhesive layer described in Examples 1-5 and Comparative Examples 1-2 is attached. The film is then vulcanized at 190°C for 60 seconds to prepare a hot transfer silicone trademark. The thickness of the hot transfer silicone trademark is 3mm and the size is 35mm×25mm.

[0156] Test at 150℃ and 180℃ respectively, transfer silicone trademarks to the surface of the substrate such as fabric with 2Kg and 10s heat pressing, and observe whether the hot melt adhesive film and silicone delaminate.

[0157] The silicone trademark pressed onto the fabric surface was washed 10 times in a 40℃ washing machine. After drying, the hot melt adhesive film and silicone were observed to see if they separated, and their bonding strength was tested using GB / T39289-2020. The test results for pressing at 150℃ are shown in Table 1, and the test results for pressing at 180℃ are shown in Table 2.

[0158] Table 1

[0159]

[0160] Table 2

[0161]

[0162]

[0163] In Tables 1 and 2, the layer dimensions represent the layer length, and the sharp corner layer dimensions represent the layer length. The layer length refers to the layering of the heat transfer silicone trademark part, and the distance from the edge of the layered part to the edge of the unlayered part is the layer length.

[0164] From Table 1 and Table 2, we can see that:

[0165] (1) As can be seen from Examples 1-4, the hot melt adhesive films prepared by melt casting method and solution coating method in this application are of stable quality. There is no delamination or peeling during the test process. They can be applied to a wider range of heat pressing conditions, thereby reducing the impact on transfer equipment, production environment and operator proficiency, and improving the stability of product quality.

[0166] The three-layer structure of the hot melt adhesive film in this application successfully avoids the limitation that silicone is not easily adhered to by hot melt adhesive. Even for thick silicone trademarks with small areas, it can avoid the problem of silicone layer peeling and delamination.

[0167] During the transfer process, this application maintains the solid properties of the high-temperature resistant layer, the silicone adhesive layer, and the silicone layer, ensuring the stability and firmness of the easily delaminated interface. That is, between the carbon-based materials and the silicon-based materials, only the hot melt adhesive and the high-temperature resistant layer undergo a phase change. However, both the hot melt adhesive and the high-temperature resistant layer are carbon-based materials with good compatibility. Furthermore, by matching the material similarity between the hot melt adhesive and the high-temperature resistant layer, they have similar physical and chemical properties. The liquid hot melt adhesive can completely wet and penetrate into the surface of the high-temperature resistant layer, forming hydrogen bonds and molecular-level entanglement, and even forming a certain amount of chemical bonds at high temperatures, ensuring the interfacial adhesion between the hot melt adhesive layer and the high-temperature resistant layer.

[0168] (2) As can be seen from Example 5, the application uses hot melt adhesives with different melting points in a reasonable combination, which is conducive to the hot melt adhesive having a large gradient in the process of changing from liquid to solid, ensuring that its cooling and curing is a slow process. The gradual curing process is conducive to releasing cohesion, reducing the shrinkage of the hot melt adhesive, and preventing the edges from lifting.

[0169] (3) As can be seen from Comparative Examples 1-2, the three-layer structure of the hot melt adhesive film in this application maintains the solid properties of the high temperature resistant layer during the transfer process, providing a stable contact interface for the silicone adhesive layer and the hot melt adhesive layer, successfully avoiding the limitation that silicone is not easy to be adhered by hot melt adhesive. Even for thick silicone trademarks with small areas, the problem of silicone layer peeling and delamination can be avoided.

[0170] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0171] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A transfer hot melt adhesive film, characterized in that, The transfer hot melt adhesive film includes a hot melt adhesive layer, a high-temperature resistant layer and a silicone adhesive layer stacked in sequence; The material of the silicone adhesive layer includes carbon chain compounds containing olefin groups or modified siloxanes, wherein the modified siloxane is a modified siloxane containing at least one of hydroxyl, epoxy and olefin groups. The melting point of the high-temperature resistant layer is greater than that of the hot melt adhesive layer, and the material of the high-temperature resistant layer includes at least one of polyurethane, acrylate and polyester compounds; The hot melt adhesive layer is made of a first thermoplastic polyurethane and a second thermoplastic polyurethane, wherein the melting point of the first thermoplastic polyurethane is 60~100℃ and the melting point of the second thermoplastic polyurethane is 120~150℃.

2. The transfer hot melt adhesive film as described in claim 1, characterized in that, The thickness of the silicone adhesive layer is 0.01~0.10mm.

3. The transfer hot melt adhesive film as described in claim 1, characterized in that, The olefin-containing carbon chain compound includes at least one of the following: polyurethane containing vinyl segments, acrylate containing vinyl segments, polyester compound containing vinyl segments, polyurethane containing butadiene segments, acrylate containing butadiene segments, and polyester compound containing butadiene segments.

4. The transfer hot melt adhesive film as described in claim 1, characterized in that, The high-temperature resistant layer satisfies at least one of the following conditions: (1) The hardness of the high-temperature resistant layer is 50~100A; (2) The thickness of the high temperature resistant layer is 0.02~0.10mm.

5. The transfer hot melt adhesive film according to any one of claims 1-4, characterized in that, The hot melt adhesive layer satisfies at least one of the following conditions: (1) The material of the hot melt adhesive layer includes at least one of thermoplastic polyurethane, acrylate, polyester compound and ethylene-vinyl acetate copolymer; (2) The melting point of the hot melt adhesive layer is 60~150℃; (3) The hardness of the hot melt adhesive layer is 50~100A; (4) The thickness of the hot melt adhesive layer is 0.08~0.20mm.

6. The transfer hot melt adhesive film as described in claim 1, characterized in that, The hot melt adhesive layer is prepared by melt casting method, and the raw material composition of the hot melt adhesive layer is as follows according to mass parts: The first thermoplastic polyurethane: 19.8-44 parts; 45-75 parts of the second thermoplastic polyurethane.

7. The transfer hot melt adhesive film as described in claim 6, characterized in that, The raw materials of the hot melt adhesive layer also include additives, including cosolvents, antioxidants, and ultraviolet absorbers. The raw material composition of the hot melt adhesive layer, by weight, is as follows: The first thermoplastic polyurethane: 19.8-44 parts; 45-75 parts of the second thermoplastic polyurethane; 5-10 parts of co-solvent; Antioxidant 0.1~0.5 parts; 0.1 to 0.5 parts of ultraviolet absorber.

8. The transfer hot melt adhesive film as described in claim 1, characterized in that, The hot melt adhesive layer is prepared by solution coating method, and the raw material composition of the hot melt adhesive layer is as follows, according to parts by mass: 6-13 parts of the first thermoplastic polyurethane; 14-27 parts of the second thermoplastic polyurethane; Solvent: 66.7-78.4 parts.

9. The transfer hot melt adhesive film as described in claim 8, characterized in that, The raw materials of the hot melt adhesive layer also include additives, including cosolvents, antioxidants, and ultraviolet absorbers. The raw material composition of the hot melt adhesive layer, by weight, is as follows: 6-13 parts of the first thermoplastic polyurethane; 14-27 parts of the second thermoplastic polyurethane; Solvent: 66.7~78.4 parts; Co-solvent 1.54~3 parts; Antioxidant 0.03~0.15 parts; 0.03~0.15 parts of ultraviolet absorber.

10. A method for preparing a transfer hot melt adhesive film according to any one of claims 1-5, characterized in that, The preparation method includes: Hot melt adhesive material is mixed with an additive solution to obtain a hot melt adhesive slurry, and a hot melt adhesive layer is prepared using the hot melt adhesive slurry. A high-temperature resistant layer and a silicone adhesive layer are sequentially deposited on the surface of the hot melt adhesive layer to prepare the transfer hot melt adhesive film.

11. The preparation method according to claim 10, characterized in that, The additive solution includes antioxidants and ultraviolet absorbers.

12. The preparation method according to claim 10, characterized in that, The high-temperature resistant layer is formed by screen printing or coating, and the silicone adhesive layer is formed by screen printing or coating.

13. A method for preparing the transfer hot melt adhesive film according to claim 6 or 7, characterized in that, The preparation method includes: Hot melt adhesive material is mixed with an additive solution to obtain a hot melt adhesive slurry, and a hot melt adhesive layer is prepared from the hot melt adhesive slurry using a melt casting method. A high-temperature resistant layer and a silicone adhesive layer are sequentially deposited on the surface of the hot melt adhesive layer to prepare the transfer hot melt adhesive film.

14. The preparation method according to claim 13, characterized in that, The melt casting method includes: mixing hot melt adhesive material with an additive solution, and then sequentially melting, granulating and casting to form a hot melt adhesive layer.

15. The preparation method according to claim 13, characterized in that, The additive solution also includes a solubilizer, an antioxidant, and an ultraviolet absorber.

16. The preparation method according to claim 13, characterized in that, The high-temperature resistant layer is formed by screen printing or coating, and the silicone adhesive layer is formed by screen printing or coating.

17. A method for preparing the transfer hot melt adhesive film according to claim 8 or 9, characterized in that, The preparation method includes: Hot melt adhesive material is mixed with an additive solution to obtain a hot melt adhesive slurry, and a hot melt adhesive layer is prepared from the hot melt adhesive slurry using a solution coating method. A high-temperature resistant layer and a silicone adhesive layer are sequentially deposited on the surface of the hot melt adhesive layer to prepare the transfer hot melt adhesive film.

18. The preparation method according to claim 17, characterized in that, The solution coating method includes: mixing hot melt adhesive material, additive solution and solvent to obtain hot melt adhesive slurry, and coating to form a hot melt adhesive layer.

19. The preparation method according to claim 17, characterized in that, The additive solution includes a solubilizer, an antioxidant, and an ultraviolet absorber.

20. The preparation method according to claim 17, characterized in that, The high-temperature resistant layer is formed by screen printing or coating, and the silicone adhesive layer is formed by screen printing or coating.

21. An application of the transfer hot melt adhesive film according to any one of claims 1-9, characterized in that, The transfer hot melt adhesive film is used for silicone transfer.

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