High-speed transmission hot melt adhesive film having high adhesion to metal and preparation method therefor

Abstract

A high-speed transmission hot melt adhesive film having high adhesion to metal and a preparation method therefor, which belong to the technical field of high-speed transmission hot melt adhesive films. The high-speed transmission hot melt adhesive film having high adhesion to metal sequentially comprises, from bottom to top, a PET film and an insulating adhesive layer, wherein the insulating adhesive layer is prepared from the following raw materials in parts by mass: 10-25 parts of a maleic-anhydride-modified polyolefin resin, 8-25 parts of a flame retardant, and 2-5 parts of polypropylene powder. The high-speed transmission hot melt adhesive film for an FFC has a very strong adhesive force on a metal conductor, can achieve the purpose of directly adhering to the conductor, and barely has the problem of the detachment of the metal conductor from pins after a later gold plating process, thereby greatly improving the yield of FFC cables, solving the problem of the decreased yield of FFC cables due to an existing hot melt adhesive film being adhered to a conductor by means of a gasket, and also significantly improving the signal transmission rate of FFC cables and reducing attenuation.

Description

A high-speed transmission hot-melt adhesive film with high metal adhesion and its preparation method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application with application number 202311761947.X filed with the Patent Office of China on December 20, 2023, entitled "A high-speed transmission hot-melt adhesive film with high metal adhesion and its preparation method", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present invention relates to the technical field of hot melt adhesive films, and in particular to a high-speed transmission hot melt adhesive film with high metal adhesion and a preparation method thereof. Background Art

[0004] Flexible Flat Cable (FFC) is a new type of data cable made of hot-melt adhesive film and extremely thin tinned flat conductors, which are pressed together through an automated production line.

[0005] Common hot melt adhesive films usually include PET film and an insulating adhesive layer. Currently, the insulating adhesive layer in hot melt adhesive films generally uses polyester resin as the main material. Since polyester resin has low adhesion to metal conductors (copper wires) or the amount of adhesive overflow at the port is relatively large, it is usually necessary to first add a gasket with high metal adhesion to the outside of the conductor located at the FFC wire port to achieve the effect of adhering to the metal conductor, and then affix the hot melt adhesive film to the outside of the gasket. Because the gasket has a certain thickness and in order to ensure that the gasket meets the requirements of anti-glue overflow, it is usually required that the gasket's fluidity during high temperature (160℃~210℃) pressing is not too good. This makes the gasket relatively hard. After the conductor, gasket and PET insulating film are pressed together, it is easy to cause gaps between the gasket and the hot melt adhesive film, causing holes in the pressed product. Since the pressed product must subsequently be placed in an electroplating bath for gold plating, the presence of holes between the gasket and the hot-melt adhesive film can easily allow the plating bath to seep into the FFC cable during gold plating, leading to conductor de-pinning and significantly reducing the yield of the FFC cable. Furthermore, since the insulating layer in existing hot-melt adhesive films is primarily made of polyester resin, which has a high dielectric constant, this results in slower signal transmission speeds in FFC cables made with these films. Therefore, there is an urgent need to develop a hot-melt adhesive film for FFC that can directly adhere to conductors without the use of gaskets and exhibits a higher transmission rate.

[0006] Summary of the Invention

[0007] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to propose a high-speed transmission hot-melt adhesive film with high metal adhesion, which has strong adhesion to metal conductors and can achieve the purpose of directly bonding the conductors. After the later gold plating process, there is almost no problem of metal conductor PIN debonding, which greatly improves the yield of FFC wires and solves the problem that the yield of FFC wires will be reduced by bonding conductors through gaskets using existing hot-melt adhesive films. At the same time, the hot-melt adhesive film uses polyolefin materials with low dielectric constant and loss factor to prepare FFC wires, which can improve the transmission rate of FFC wires and reduce the attenuation of FFC wires.

[0008] Another object of the present invention is to provide a method for preparing a high-speed transmission hot-melt adhesive film with high metal adhesion, which can produce a hot-melt adhesive film for FFC that can be directly attached to the conductor and has high-speed transmission function.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] A high-speed transmission hot melt adhesive film with high metal adhesion, comprising a PET film and an insulating adhesive layer from bottom to top;

[0011] Calculated by mass, the raw materials of the insulating adhesive layer include 10 to 25 parts of maleic anhydride modified polyolefin resin, 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder.

[0012] Preferably, the maleic anhydride modified polyolefin resin is a resin having a styrene-butadiene-styrene block copolymer as a main body and maleic anhydride grafted at both ends of the main body.

[0013] Preferably, calculated as a percentage by mass, the grafting amount of maleic anhydride in the maleic anhydride-modified polyolefin resin is 1.2-1.5%.

[0014] Preferably, the particle size of the polypropylene powder is ≤5 μm.

[0015] Preferably, the flame retardant is a bromine-containing flame retardant or a halogen-free flame retardant.

[0016] Preferably, the thickness of the PET film is 7 to 100 μm, and the thickness of the insulating adhesive layer is 5 to 100 μm.

[0017] Preferably, calculated by mass, the raw materials of the insulating adhesive layer further include 40 to 80 parts of toluene solvent.

[0018] A method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion, for preparing the high-speed transmission hot melt adhesive film with high metal adhesion, comprises the following steps:

[0019] (1) Add 10 to 25 parts of maleic anhydride modified polyolefin resin to 40 to 80 parts of toluene solvent by weight, and after the maleic anhydride modified polyolefin resin is completely dissolved, add 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder in sequence, and disperse them evenly to obtain an insulating adhesive;

[0020] (2) coating the surface of the PET film with insulating adhesive to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot melt adhesive film with high metal adhesion.

[0021] The technical solutions provided by the embodiments of the present application can have the following beneficial effects: The main material of the insulating adhesive layer of the present invention is a maleic anhydride-modified polyolefin resin, with maleic anhydride grafted onto both ends of the maleic anhydride-modified polyolefin resin. Maleic anhydride can form chemical bonds or physical adsorption with the metal conductor, significantly increasing the bonding strength between the insulating adhesive layer and the metal conductor. This ensures that the high-speed transmission hot-melt adhesive film used in the present invention for FFCs has strong adhesion to the metal conductor, enabling direct bonding to the conductor without the use of a gasket. Since no gasket is required, after lamination, the high-speed transmission hot-melt adhesive film of the present invention and the metal conductor can be tightly bonded, with virtually no gaps or holes. Therefore, the problem of metal conductor de-pinning after subsequent gold plating is virtually eliminated, significantly improving the yield rate of FFC cables. Furthermore, since the high-speed transmission hot-melt adhesive film of the present invention is directly bonded to the metal conductor, no gasket is required, eliminating the gasketing step and significantly reducing the difficulty and time required to manufacture the FFC cables. At the same time, the insulating adhesive layer of this technical solution uses polyolefin materials with low dielectric constant and loss factor. Compared with the FFC wire prepared by ordinary polyester hot melt adhesive film, the FFC wire pressed with the hot melt adhesive film of this solution has a higher transmission rate and can reduce the attenuation of the FFC wire. DETAILED DESCRIPTION

[0022] For ease of understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0023] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in this field or the product instructions were used. Raw materials used without manufacturer specified are all commercially available conventional products.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0026] A high-speed transmission hot melt adhesive film with high metal adhesion, comprising a PET film and an insulating adhesive layer from bottom to top;

[0027] Calculated by mass, the raw materials of the insulating adhesive layer include 10 to 25 parts of maleic anhydride modified polyolefin resin, 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder.

[0028] It is worth noting that the main material of the insulating adhesive layer of the present technical solution is maleic anhydride modified polyolefin resin, and maleic anhydride is grafted on both ends of the maleic anhydride modified polyolefin resin. Maleic anhydride can form chemical bonds or physical adsorption with the metal conductor, which can significantly increase the bonding strength between the insulating adhesive layer and the metal conductor, so that the high-speed transmission hot melt adhesive film used for FFC wires in the present technical solution has strong adhesion to the metal conductor, and can achieve the purpose of directly bonding the conductor without using a gasket. Since there is no need for a gasket, after pressing, the high-speed transmission hot melt adhesive film and the metal conductor can be tightly bonded with each other, with basically no gaps or holes. Therefore, after the later gold plating process, there is almost no problem of metal conductor PIN debonding, which greatly improves the yield of FFC wires. Moreover, since the high-speed transmission hot melt adhesive film of the present technical solution is directly bonded to the metal conductor, there is no need for a gasket, which saves the step of gasketing and greatly reduces the difficulty and time of making FFC wires.

[0029] Further explanation: Because the main material of the insulating adhesive layer in traditional hot-melt adhesive films is polyester resin, which has a high dielectric constant, typically around 3.0 to 6.0, this results in slow signal transmission speeds in FFC cables made with traditional hot-melt adhesive films. The main material of the insulating adhesive layer in this technical solution is maleic anhydride-modified polyolefin resin, which has a low dielectric constant and dissipation factor. Using the hot-melt adhesive film of this technical solution with FFC cables can significantly increase the transmission rate of FFC cables and reduce their attenuation. Therefore, FFC cables made with the high-speed transmission hot-melt adhesive film of this technical solution have high-speed transmission capabilities.

[0030] Specifically, the raw materials of the insulating adhesive layer include 10 to 25 parts of maleic anhydride-modified polyolefin resin, 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder. Under this formula, the insulating adhesive layer not only has excellent metal adhesion and can achieve the purpose of directly sticking to the conductor, but also under this formula, the maleic anhydride-modified polyolefin resin and PP powder can increase the softening point of the insulating adhesive layer to 120 to 160°C, increase the insulation adhesive layer's anti-overflow ability, and the insulation adhesive layer will not have anti-stickiness. At the same time, by adding 8 to 25 parts of flame retardant, the insulating adhesive layer can reach the UL94VTM-0 flame retardant level.

[0031] Further explanation: the PET film in the high-speed transmission hot melt adhesive film of this technical solution is a film using PET as the main material, which is the base material of the high-speed transmission hot melt adhesive film. The PET film of this technical solution can be purchased on the market or prepared using existing conventional formulas and processes.

[0032] To further illustrate, the maleic anhydride modified polyolefin resin is a resin having a styrene-butadiene-styrene block copolymer as a main body and maleic anhydride grafted at both ends of the main body.

[0033] The maleic anhydride-modified polyolefin resin used in the technical solution has maleic anhydride grafted on both ends, which can significantly improve the adhesion of the insulating adhesive layer to the conductor.

[0034] It is worth noting that the main component of the maleic anhydride-modified polyolefin resin in this technical solution is a polyolefin resin, and more preferably, a styrene-butadiene-styrene block copolymer. Compared to other polymers, polyolefin resins have lower dielectric constants and dissipation factors, making them more conducive to the transmission of FFC cable signals. Compared with conventional polyester-grafted maleic anhydride, the modified resin in this technical solution with a styrene-butadiene-styrene block copolymer as the main component has a dielectric constant of approximately 2.2 to 2.3 and a dissipation factor of approximately 0.003 to 0.004. Other maleic anhydride-modified polymers have higher dielectric constants and dissipation factors, especially polyester-based maleic anhydride-modified resins, which have dielectric constants and dissipation factors far higher than those of maleic anhydride-modified polyolefin resins. Therefore, if other polymers are used as the main material, the transmission effect of the modified resin obtained is far inferior to the transmission effect of the hot melt adhesive film made with a styrene-butadiene-styrene block copolymer as the main component.

[0035] To further illustrate, calculated by mass percentage, the grafting amount of maleic anhydride in the maleic anhydride-modified polyolefin resin is 1.2-1.5%.

[0036] It is worth noting that the maleic anhydride-modified polyolefin resin of the present technical solution is based on a styrene-butadiene-styrene block copolymer, with 1.2% to 1.5% maleic anhydride grafted at both ends, so that the maleic anhydride-modified polyolefin resin has excellent adhesion to the metal conductor, so that the high-speed transmission hot melt adhesive film for FFC of the present technical solution can achieve the purpose of directly sticking to the conductor without a gasket, greatly improving the yield of FFC wires, and can increase the transmission rate of FFC wires and reduce the attenuation of FFC wires.

[0037] Further explanation: the softening point of the maleic anhydride-modified polyolefin resin of the present technical solution is about 90-165°C. Since the FFC line port position has certain requirements on the amount of glue overflow, the maleic anhydride-modified polyolefin resin at this softening point, combined with 2-5 parts of polypropylene powder (PP powder), can increase the softening point of the insulating adhesive layer to 130-160°C, giving it better anti-glue overflow function.

[0038] Preferably, the maleic anhydride modified polyolefin resin of the present technical solution is a resin with a medium molecular weight. Preferably, the molecular weight of the maleic anhydride modified polyolefin resin is 100,000 to 180,000.

[0039] Further description, the particle size of the polypropylene powder is ≤5 μm.

[0040] This technical solution not only reduces back-sticking by adding polypropylene powder (PP powder) with a particle size of ≤5μm into the insulating adhesive layer, but also increases the softening point of the insulating adhesive layer, giving it better anti-overflow function.

[0041] Specifically, if the particle size of PP powder is ≤5μm, it can be more evenly dispersed in the insulating adhesive layer, making the surface of the insulating adhesive layer finer and there will not be too large particles when coating the insulating adhesive; if the particle size of PP powder is too large, it will be difficult for PP powder to be evenly dispersed in the insulating adhesive, and the coating appearance will be relatively rough. After being pressed into FFC wire, there will be many particles on the wire body.

[0042] To further illustrate, the flame retardant is a bromine-containing flame retardant or a halogen-free flame retardant.

[0043] In the present technical solution, (3) the flame retardant is a common bromine-containing flame retardant or a halogen-free flame retardant, etc., which is added to the insulating rubber layer to play a flame retardant role.

[0044] To further illustrate, the thickness of the PET film is 7 to 100 μm, and the thickness of the insulating adhesive layer is 5 to 100 μm.

[0045] Specifically, the thickness of the PET film in the high-speed transmission hot-melt adhesive film for FFC in this technical solution is 7μm to 100μm, which can be selected according to the application scenario requirements of the FFC wire. The thickness of the insulating adhesive layer in this technical solution should not be less than 5μm. Preferably, the thickness of the insulating adhesive layer is 5-100μm, and more preferably, the thickness of the insulating adhesive layer is 5-50μm. If the thickness of the insulating adhesive layer is too thin, the fluidity is insufficient during high-temperature pressing, resulting in insufficient adhesion to the conductor. If the thickness of the insulating adhesive layer is too thick, it is not easy to apply it in one go.

[0046] Further explanation: calculated by mass, the raw materials of the insulating adhesive layer also include 40 to 80 parts of toluene solvent.

[0047] A method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion, for preparing the high-speed transmission hot melt adhesive film with high metal adhesion, comprises the following steps:

[0048] (1) Add 10 to 25 parts of maleic anhydride modified polyolefin resin to 40 to 80 parts of toluene solvent by weight, and after the maleic anhydride modified polyolefin resin is completely dissolved, add 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder in sequence, and disperse them evenly to obtain an insulating adhesive;

[0049] (2) Insulating adhesive is coated on the surface of the PET film to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot-melt adhesive film with high metal adhesion.

[0050] It is worth noting that, in this technical solution, insulating adhesive is first coated on the PET film to prepare a hot melt adhesive film for FFC that can be directly attached to the conductor and has high-speed transmission function.

[0051] The technical solution of the present invention is further described below in conjunction with embodiments and comparative examples.

[0052] Example 1

[0053] The high-speed transmission hot melt adhesive film of this embodiment with high metal adhesion comprises, from bottom to top, a PET film and an insulating adhesive layer; wherein the thickness of the PET film is 50 μm, and the thickness of the insulating adhesive layer is 20 μm;

[0054] Calculated by weight, the raw materials of the insulating adhesive layer include 20 parts of maleic anhydride modified polyolefin resin, 18 parts of flame retardant and 2 parts of polypropylene powder; wherein the particle size of the polypropylene powder is ≤5μm; the flame retardant is a bromine-containing flame retardant;

[0055] The maleic anhydride modified polyolefin resin used in the insulating adhesive layer is a resin with a styrene-butadiene-styrene block copolymer as the main body and maleic anhydride grafted at both ends of the main body. Calculated by mass percentage, the grafting amount of maleic anhydride in the maleic anhydride modified polyolefin resin is 1.4%.

[0056] The method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion in this embodiment includes the following steps:

[0057] (1) First, add 60 parts of toluene solvent into a disperser, then add 20 parts of maleic anhydride modified polyolefin resin, and after the maleic anhydride modified polyolefin resin is completely dissolved, add 18 parts of flame retardant, disperse evenly, and then add 2 parts of polypropylene powder and disperse evenly to obtain an insulating adhesive;

[0058] (2) Insulating adhesive is coated on the surface of the PET film to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot-melt adhesive film with high metal adhesion.

[0059] Example 2

[0060] The high-speed transmission hot melt adhesive film of this embodiment with high metal adhesion comprises, from bottom to top, a PET film and an insulating adhesive layer; wherein the thickness of the PET film is 50 μm, and the thickness of the insulating adhesive layer is 20 μm;

[0061] Calculated by weight, the raw materials of the insulating adhesive layer include 18.5 parts of maleic anhydride modified polyolefin resin, 25 parts of flame retardant and 3.5 parts of polypropylene powder; wherein the particle size of the polypropylene powder is ≤5μm; the flame retardant is a halogen-free flame retardant;

[0062] The maleic anhydride modified polyolefin resin used in the insulating adhesive layer is a resin with a styrene-butadiene-styrene block copolymer as the main body and maleic anhydride grafted at both ends of the main body. Calculated by mass percentage, the graft amount of maleic anhydride in the maleic anhydride modified polyolefin resin is 1.4%.

[0063] The method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion in this embodiment includes the following steps:

[0064] (1) First, add 53 parts of toluene solvent into a disperser, then add 18.5 parts of maleic anhydride modified polyolefin resin, and after the maleic anhydride modified polyolefin resin is completely dissolved, add 25 parts of flame retardant, disperse evenly, and then add 3.5 parts of polypropylene powder and disperse evenly to obtain an insulating adhesive;

[0065] (2) Insulating adhesive is coated on the surface of the PET film to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot-melt adhesive film with high metal adhesion.

[0066] Example 3

[0067] The high-speed transmission hot melt adhesive film of this embodiment with high metal adhesion comprises, from bottom to top, a PET film, a primer layer, and an insulating adhesive layer; wherein the thickness of the PET film is 50 μm, and the thickness of the insulating adhesive layer is 20 μm;

[0068] Calculated by weight, the raw materials of the insulating adhesive layer include 17 parts of maleic anhydride modified polyolefin resin, 18 parts of flame retardant and 5 parts of polypropylene powder; wherein the particle size of the polypropylene powder is ≤5μm; the flame retardant is a bromine-containing flame retardant;

[0069] The maleic anhydride modified polyolefin resin used in the insulating adhesive layer is a resin with a styrene-butadiene-styrene block copolymer as the main body and maleic anhydride grafted at both ends of the main body. Calculated by mass percentage, the grafting amount of maleic anhydride in the maleic anhydride modified polyolefin resin is 1.4%.

[0070] The method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion in this embodiment includes the following steps:

[0071] (1) First, add 60 parts of toluene solvent into a disperser, then add 17 parts of maleic anhydride modified polyolefin resin, and after the maleic anhydride modified polyolefin resin is completely dissolved, add 18 parts of flame retardant, disperse evenly, and then add 5 parts of polypropylene powder and disperse evenly to obtain an insulating adhesive;

[0072] (2) Insulating adhesive is coated on the surface of the PET film to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot-melt adhesive film with high metal adhesion.

[0073] Comparative Example 1

[0074] This comparative example is a traditional hot melt adhesive film for FFC.

[0075] Specifically, conventional hot melt adhesive film performance testing methods in the art were used to test the anti-sticking and softening points of the insulating adhesive layers in the high-speed transmission hot melt adhesive films of Examples 1-3 and the conventional hot melt adhesive film for FFCs of Comparative Example 1. The test data are shown in Table 1 below. Simultaneously, the high-speed transmission hot melt adhesive films for FFCs of Examples 1-3 and the conventional hot melt adhesive film for FFCs of Comparative Example 1 were laminated to conductors, respectively. The conductor specifications and lamination conditions were as follows:

[0076] Conductor specifications: 0.05mm thickness × 0.3mm width bare copper conductor, conductor spacing 0.5mm;

[0077] Pressing conditions: pressing temperature 180°C, pressure: 0.5MPa, speed: 1.2m / min;

[0078] After lamination under the above lamination conditions, the adhesion of the high-speed transmission hot melt adhesive film to the 0.3 mm width bare copper conductor obtained after lamination was tested using a test method commonly used in the field. The test results are shown in Table 1 below.

[0079] Table 1 Performance test results

[0080] The data in Table 1 demonstrates that, compared to the conventional hot-melt adhesive film for FFCs in Comparative Example 1, the high-speed transmission hot-melt adhesive films of Examples 1-3 exhibit significantly greater adhesion to bare copper conductors (0.3 mm width) than the conventional hot-melt adhesive film for FFCs in Comparative Example 1, ranging from 39.7 to 51.4 g / 0.3 mm. Furthermore, the high-speed transmission hot-melt adhesive film produced using the insulating adhesive formulation of Example 1 exhibits the highest adhesion to bare copper conductors (0.3 mm width), reaching 51.4 g / 0.3 mm. Furthermore, the insulating adhesive layers of Examples 1-3 exhibit low back-tack, all less than 0.15 N / 50 mm. Furthermore, the insulating adhesive layers of Examples 1-3 exhibit higher softening points than those of Comparative Example 1, demonstrating improved adhesive overflow resistance.

[0081] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A high-speed transmission hot melt adhesive film with high metal adhesion, characterized in that: From bottom to top, it includes a PET film and an insulating adhesive layer; Calculated by weight, the raw materials of the insulating adhesive layer include 10 to 25 parts of maleic anhydride modified polyolefin resin, 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder.

2. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 1, characterized in that: The maleic anhydride modified polyolefin resin is a resin with a copolymer of styrene-butadiene-styrene blocks as the main body and maleic anhydride grafted on both ends of the main body.

3. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 2, characterized in that: Calculated by mass percentage, the grafting amount of maleic anhydride in the maleic anhydride modified polyolefin resin is 1.2-1.5%.

4. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 1, characterized in that: The particle size of the polypropylene powder is ≤5 μm.

5. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 1, characterized in that: The flame retardant is a bromine-containing flame retardant or a halogen-free flame retardant.

6. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 1, characterized in that: The thickness of the PET film is 7-100 μm, and the thickness of the insulating adhesive layer is 5-100 μm.

7. The high-speed transmission hot melt adhesive film with high metal adhesion according to claim 1, characterized in that: Calculated by weight, the raw materials of the insulating adhesive layer also include 40 to 80 parts of toluene solvent.

8. A method for preparing a high-speed transmission hot melt adhesive film with high metal adhesion, characterized in that: The method for preparing the high-speed transmission hot melt adhesive film with high metal adhesion according to any one of claims 1 to 7 comprises the following steps: (1) adding 10 to 25 parts of maleic anhydride modified polyolefin resin to 40 to 80 parts of toluene solvent by weight, and after the maleic anhydride modified polyolefin resin is completely dissolved, adding 8 to 25 parts of flame retardant and 2 to 5 parts of polypropylene powder in sequence, and dispersing them evenly to obtain an insulating adhesive; (2) coating an insulating adhesive on the surface of the PET film to obtain an insulating adhesive layer, thereby preparing a high-speed transmission hot-melt adhesive film with high metal adhesion.

Images