Hot melt adhesive film for ultra-high-speed transmission FFC (flexible flat cable) and preparation method of hot melt adhesive film

Abstract

The invention discloses a hot melt adhesive film for an ultra-high-speed transmission FFC (flexible flat cable) and a preparation method of the hot melt adhesive film. The hot melt adhesive film is formed by coating insulating glue and then curing the insulating glue; the insulating glue comprises the following components in parts by mass: 40-80 parts of a toluene solvent, 20-40 parts of foamed polyolefin resin and 20-50 parts of a halogen-free flame retardant, the foamed polyolefin resin comprises modified polyolefin, a foaming agent and a catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50: 1. In addition, the invention further provides a preparation method of the hot melt adhesive film for the ultra-high-speed transmission FFC, and the hot melt adhesive film for the ultra-high-speed transmission FFC and the preparation method of the hot melt adhesive film for the ultra-high-speed transmission FFC solve the problem that in the prior art, a hot melt adhesive film of an FFC wire cannot give consideration to the high-temperature performance and the high transmission performance at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt adhesive films, and in particular to a hot melt adhesive film for FFC with ultra-high-speed transmission and a preparation method thereof. Background Art

[0002] Flexible Flat Cable (FFC) is a new type of data cable made of hot-melt adhesive film and extremely thin tinned flat conductors, pressed together through an automated production line.

[0003] In the prior art, the hot melt adhesive film of FFC wire is made of PET insulating material plus a certain thickness of fireproof insulating adhesive. The FFC wire made by this method can meet the general high-frequency transmission performance requirements. However, for transmission wires with higher requirements, this type of hot melt adhesive film cannot meet the higher transmission function requirements after being pressed into FFC wires. This is because the relative dielectric constant (Dk) of PET itself is 3.2, and its loss factor (Df) is 0.006, which will greatly increase the relative dielectric constant and loss factor of the hot melt adhesive film as a whole. The larger the relative dielectric constant and loss factor, the smaller the transmission speed of the signal in the hot melt adhesive film will be, and the greater the attenuation during the transmission process will be, which will affect the transmission effect of the pressed FFC wire.

[0004] Although PET insulation material will affect the transmission effect of FFC wires, it can be used at higher temperatures, which allows FFC wires to maintain corresponding performance in high temperature environments. In order to ensure the transmission effect of FFC wires, other insulation materials are generally used to replace PET in the prior art, and the high temperature resistance of the above insulation materials is generally worse than that of PET, resulting in the hot melt adhesive film being unable to take into account both high temperature resistance and high transmission performance. Summary of the invention

[0005] The purpose of the present invention is to provide a hot melt adhesive film for FFC with ultra-high-speed transmission, so as to solve the problem that the hot melt adhesive film of FFC wire in the prior art cannot take into account both high temperature performance and high transmission performance.

[0006] The second purpose of the present invention is to provide a method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission, so as to ensure that the obtained hot melt adhesive film can take into account both high temperature performance and high transmission performance and meet actual product standards.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] A hot melt adhesive film for FFC with ultra-high-speed transmission, which is formed by coating and curing the insulating adhesive;

[0009] Calculated by weight, the insulating adhesive includes 40-80 parts of toluene solvent, 20-40 parts of foamed polyolefin resin and 20-50 parts of halogen-free flame retardant;

[0010] The foamed polyolefin resin comprises modified polyolefin, a foaming agent and a catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1.

[0011] Preferably, the molecular weight of the foamed polyolefin resin is greater than 150,000.

[0012] Preferably, the main chain of the foamed polyolefin resin is styrene-butadiene-styrene copolymer.

[0013] Preferably, the foaming agent is a carbonate foaming agent.

[0014] Preferably, the halogen-free flame retardant is a phosphorus-nitrogen series flame retardant.

[0015] A method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission, which is used to prepare the above-mentioned hot melt adhesive film for FFC with ultra-high-speed transmission, comprises the following steps:

[0016] A: According to the formula of the insulating adhesive, a formulated amount of toluene solvent and a foamed polyolefin resin are mixed at a high speed, and after the foamed polyolefin resin is completely dissolved, a formulated amount of halogen-free flame retardant is added, and the mixture is evenly mixed to obtain the insulating adhesive;

[0017] B: coating the insulating adhesive on a release film, and removing the release film after baking and curing to obtain the hot melt adhesive film for FFC with ultra-high-speed transmission.

[0018] Preferably, the extrusion temperature for preparing the foamed polyolefin resin is 150-300° C., and the extrusion speed is 5-20 r / min.

[0019] Preferably, in step A, the rotation speed of the high-speed mixing is 500-1200 r / min.

[0020] Preferably, in step B, the coating thickness of the insulating adhesive is 10-300 μm.

[0021] Preferably, in step B, the release force of the release film is 50-100 gf.

[0022] The technical solution provided by the present invention may include the following beneficial effects:

[0023] This technical solution removes the PET layer structure in the traditional hot melt adhesive film, adopts an insulating adhesive layer with a specific formula to directly prepare the hot melt adhesive film, and selects foamed polyolefin resin, which itself has a very low relative dielectric constant and low loss factor. It works together with the halogen-free flame retardant added subsequently, so that the prepared hot melt adhesive film can have a low relative dielectric constant and loss factor, which can not only ensure that the hot melt adhesive film itself achieves a flame retardant effect, but also greatly improve the transmission function of the hot melt adhesive film. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0025] In order to facilitate the understanding of the present invention, the present invention is 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.

[0026] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] The technical solution provides a hot melt adhesive film for FFC with ultra-high-speed transmission, which is formed by coating and curing the insulating adhesive;

[0028] Calculated by weight, the insulating adhesive includes 40-80 parts of toluene solvent, 20-40 parts of foamed polyolefin resin and 20-50 parts of halogen-free flame retardant;

[0029] The foamed polyolefin resin comprises modified polyolefin, a foaming agent and a catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1.

[0030] In order to solve the technical problems existing in the prior art, this technical solution proposes a hot melt adhesive film for FFC with ultra-high-speed transmission. Compared with the hot melt adhesive film of FFC wire in the prior art, which is made of PET insulating material and fireproof insulating glue, the hot melt adhesive film proposed in this technical solution is directly formed by coating the insulating glue and then curing, eliminating the use of PET insulating material, and can effectively reduce the relative dielectric constant and loss factor of the prepared hot melt adhesive film, increase the transmission speed of the signal in the hot melt adhesive film, and reduce the attenuation of the signal during the transmission process, thereby improving the transmission effect of the pressed FFC wire. In addition, this solution also optimizes the raw materials and ratio of the insulating glue, and can obtain a hot melt adhesive film that takes into account both high temperature resistance and high transmission performance.

[0031] Specifically, the insulating adhesive comprises toluene solvent, foamed polyolefin resin and halogen-free flame retardant. The foamed polyolefin resin is dissolved in toluene solvent and serves as a substrate of the hot melt adhesive film to provide stability, and the addition of halogen-free flame retardant can ensure the flame retardant performance of the hot melt adhesive film, so that the softening point of the hot melt adhesive film is significantly improved, and the film has the function of being able to withstand high temperatures of 125°C for a long time.

[0032] However, the addition of halogen-free flame retardants will increase the relative dielectric constant of the hot melt adhesive film. In order to overcome the above-mentioned defects, this scheme selects foamed polyolefin resin as the main raw material of the insulating adhesive and uses it in combination with halogen-free flame retardants. The foamed polyolefin resin has a very low relative dielectric constant and low loss factor. After being mixed with a corresponding mass fraction of halogen-free flame retardants, the resulting hot melt adhesive film still has a low relative dielectric constant and loss factor and has good transmission performance, thereby solving the problem that the current hot melt adhesive film can achieve high temperature resistance but cannot meet higher requirements for transmission functions.

[0033] Furthermore, in the insulating adhesive, the ratio of the foamed polyolefin resin to the halogen-free flame retardant also affects the transmission performance of the obtained hot melt adhesive film. If too much halogen-free flame retardant is added, the polarity of the insulating adhesive will be greatly increased, and the relative dielectric constant and loss factor of the subsequently obtained hot melt adhesive film will be increased, affecting the transmission performance, which violates the purpose of the present technical solution. Therefore, the mass fraction of the foamed polyolefin resin is limited to 20-40 parts and the mass fraction of the halogen-free flame retardant is limited to 20-50 parts. Within this range, it is ensured that the obtained hot melt adhesive film has a lower relative dielectric constant and loss factor, that is, it takes into account both high temperature resistance and higher transmission performance, and can also give the hot melt adhesive film excellent flame retardant effect.

[0034] At the same time, the mass fraction of toluene solvent is limited to 40-80 parts, which matches the 20-40 parts of foamed polyolefin resin, so that the foamed polyolefin resin can be completely dissolved in the toluene solvent, and the insulating adhesive can have a relatively ideal viscosity (3000-10000), and the subsequent coating operation is easy to carry out and less likely to leak, and the obtained hot melt adhesive film can also have a good appearance.

[0035] In addition, the foamed polyolefin resin includes modified polyolefin, foaming agent and catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1. The foamed polyolefin resin obtained at this ratio has a relative dielectric constant of less than 2.2 and a moderate foaming density. The foamed polyolefin resin obtained further reduces its relative dielectric constant without weakening the insulation resistance and tensile strength, effectively ensuring that the voltage resistance of the subsequently obtained insulating film meets the standard, that is, the foamed polyolefin resin can have the original physical properties while having a lower relative dielectric constant and loss factor. Even after adding a certain amount of halogen-free flame retardant, the prepared hot melt adhesive film still has a lower relative dielectric constant and loss factor, which not only achieves the purpose of flame retardancy, but also effectively improves the transmission performance of the prepared hot melt adhesive film.

[0036] Preferably, the molecular weight of the foamed polyolefin resin is greater than 150,000.

[0037] If the molecular weight of the foamed polyolefin resin is less than 150,000, the softening point of the foamed polyolefin resin is low. A lower softening point means that the foamed polyolefin resin will begin to soften at a lower temperature, which limits its application in high temperature environments because it may not be able to withstand higher temperatures without losing structural integrity and cannot meet high temperature resistance requirements.

[0038] Preferably, the main chain of the foamed polyolefin resin is styrene-butadiene-styrene copolymer.

[0039] Specifically, styrene-butadiene-styrene copolymer is called the "third generation synthetic rubber", which combines the properties of plastic and rubber, that is, it has the processing convenience of plastic and the elasticity and flexibility of rubber, which is conducive to the extrusion process to obtain the foamed polyolefin resin.

[0040] Preferably, the foaming agent is a carbonate foaming agent.

[0041] Specifically, this type of foaming agent has a good nucleating effect, which means that they can form evenly distributed bubbles to meet the needs of the foamed polyolefin resin and form a foamed polyolefin resin with a lower dielectric constant and loss factor. In addition, carbonate foaming agents are relatively safe during use, especially inorganic foaming agents such as sodium bicarbonate, because the gas produced by their decomposition is carbon dioxide, which is relatively harmless to the human body and the environment.

[0042] Preferably, the carbonate foaming agent is one of calcium carbonate, magnesium carbonate and sodium bicarbonate.

[0043] Preferably, the halogen-free flame retardant is a phosphorus-nitrogen series flame retardant.

[0044] It is worth noting that the phosphorus-nitrogen series of flame retardants do not contain halogen elements, so they will not release harmful gases when burned. They comply with international environmental regulations, reduce potential harm to the environment and human body, and have excellent flame retardant properties. They can effectively prevent the spread of flames, reduce the heat generated by combustion, and improve product safety and reliability.

[0045] Preferably, the halogen-free flame retardant is one of melamine phosphate, ammonium polyphosphate and phosphate ester.

[0046] A method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission, which is used to prepare the above-mentioned hot melt adhesive film for FFC with ultra-high-speed transmission, comprises the following steps:

[0047] A: According to the formula of the insulating adhesive, a formulated amount of toluene solvent and a foamed polyolefin resin are mixed at a high speed, and after the foamed polyolefin resin is completely dissolved, a formulated amount of halogen-free flame retardant is added, and the mixture is evenly mixed to obtain the insulating adhesive;

[0048] B: coating the insulating adhesive on a release film, and removing the release film after baking and curing to obtain the hot melt adhesive film for FFC with ultra-high-speed transmission.

[0049] It should be noted that, the foamed polyolefin resin is first added, and then the toluene solvent is added to dissolve the foamed polyolefin resin, dispersed evenly at a high speed, and then the halogen-free flame retardant is added after dissolution. This allows the halogen-free flame retardant to be more fully filled in the dissolved foamed polyolefin resin. If the halogen-free flame retardant is first mixed with the toluene solvent and then added to the foamed polyolefin resin, the obtained insulating adhesive will not be uniform enough and the desired hot melt adhesive film cannot be obtained.

[0050] In the prior art, the foamed polyolefin resin is generally present in the form of sheets. In a preferred embodiment of the present technical solution, it can be cut into small pieces by a cutting machine before being added, which is conducive to the subsequent dissolution of the foamed polyolefin resin by toluene solvent.

[0051] It is further explained that the extrusion temperature for preparing the foamed polyolefin resin is 150-300° C. and the extrusion speed is 5-20 r / min.

[0052] Specifically, under the temperature and speed conditions, the foamed polyolefin particles obtained have a moderate foaming density and a high air content, so that the relative dielectric constant is 1.6-2.2 and the loss factor is 0.0002-0.0005, meeting the low dielectric requirements.

[0053] To further illustrate, in step A, the rotation speed of the high-speed mixing is 500-1200 r / min.

[0054] If the speed is higher than 1200r / min in this step, it will be dangerous and not conducive to production, while if the speed is lower than 500r / min, the foamed polyolefin resin is not easily dissolved in the toluene solvent, which increases the time cost. In short, limiting the speed within 500-1200r / min can further shorten the time and reduce the production cost under the premise of safe production.

[0055] Preferably, in step B, the coating thickness of the insulating adhesive is 10-300 μm.

[0056] If the coating thickness of the insulating adhesive is less than 10 μm during the coating step, it will easily lead to poor flame retardant effect, failure to pass the flame retardant test, and poor appearance of the crimping wire.

[0057] Preferably, in step B, the release force of the release film is 50-100 gf.

[0058] Specifically, a release film with a release force of 50-100gf is selected as the shaping material during coating. If the release force is too low, the insulating adhesive may not be easy to peel off after being coated on the release film, which may cause the hot melt adhesive film to deform. If the release force is too high, the hot melt adhesive film may automatically detach during the coating and baking process, affecting the yield of the hot melt adhesive film.

[0059] Preferably, a PET release film is selected, which has low cost and meets the required release force.

[0060] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0061] Example Group

[0062] Example 1

[0063] A: According to the formula of the insulating adhesive, 75 parts of toluene solvent and 30 parts of foamed polyolefin resin are mixed by weight, and dispersed evenly at high speed. After the foamed polyolefin resin is completely dissolved, 45 parts of halogen-free flame retardant are added to obtain the insulating adhesive; wherein the foamed polyolefin resin includes modified polyolefin, foaming agent and catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1, the foaming agent is sodium bicarbonate, and the halogen-free flame retardant is melamine phosphate;

[0064] B: The insulating adhesive is coated on a release film with a thickness of 60 μm, and the release film is removed after being baked and cured to obtain a hot melt adhesive film for FFC with ultra-high-speed transmission.

[0065] Example 2

[0066] A: According to the formula of the insulating adhesive, 60 parts of toluene solvent and 30 parts of foamed polyolefin resin are mixed by weight, and dispersed evenly at high speed. After the foamed polyolefin resin is completely dissolved, 30 parts of halogen-free flame retardant are added to obtain the insulating adhesive; wherein the foamed polyolefin resin includes modified polyolefin, foaming agent and catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1, the foaming agent is sodium bicarbonate, and the halogen-free flame retardant is melamine phosphate;

[0067] B: Coat the insulating adhesive with a thickness of 10 μm on a release film, and remove the release film after baking and curing to obtain a hot melt adhesive film for FFC with ultra-high-speed transmission.

[0068] Example 3

[0069] A: According to the formula of the insulating adhesive, 45 parts of toluene solvent and 40 parts of foamed polyolefin resin are mixed by weight, and dispersed evenly at high speed. After the foamed polyolefin resin is completely dissolved, 20 parts of halogen-free flame retardant are added to obtain the insulating adhesive; wherein the foamed polyolefin resin includes modified polyolefin, foaming agent and catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1, the foaming agent is sodium bicarbonate, and the halogen-free flame retardant is melamine phosphate;

[0070] B: coating, coating the insulating adhesive with a thickness of 300 μm on the release film, and removing the release film after baking and curing to obtain a hot melt adhesive film for FFC with ultra-high-speed transmission.

[0071] Comparative group

[0072] Comparative Example 1

[0073] A: 60 parts of toluene solvent and 30 parts of modified polyolefin resin are mixed according to the weight parts, and dispersed evenly at high speed. After the modified polyolefin resin is completely dissolved, 30 parts of halogen-free flame retardant are added to obtain insulating glue; wherein the modified polyolefin resin is the same type of modified polyolefin resin (unfoamed) in Example 1, and the halogen-free flame retardant is melamine phosphate;

[0074] B: coating the insulating adhesive with a thickness of 60 μm on a release film, and removing the release film after baking and curing to obtain a hot melt adhesive film.

[0075] Comparative Example 2

[0076] A: 75 parts of toluene solvent and 30 parts of foamed polyolefin resin are mixed according to the weight parts, and the mixture is dispersed evenly at a high speed. After the foamed polyolefin resin is completely dissolved, 10 parts of halogen-free flame retardant are added to obtain an insulating adhesive; wherein the foamed polyolefin resin comprises a modified polyolefin, a foaming agent and a catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:1, the foaming agent is sodium bicarbonate, and the halogen-free flame retardant is melamine phosphate;

[0077] B: coating the insulating adhesive with a thickness of 60 μm on a release film, and removing the release film after baking and curing to obtain a hot melt adhesive film.

[0078] Comparative Example 3

[0079] A: Calculated by weight, 75 parts of toluene solvent and 30 parts of foamed polyolefin resin are mixed and dispersed evenly at high speed. After the foamed polyolefin resin is completely dissolved, 45 parts of halogen-free flame retardant are added to obtain the insulating adhesive; wherein the foamed polyolefin resin includes modified polyolefin, foaming agent and catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 100:1, the foaming agent is sodium bicarbonate, and the halogen-free flame retardant is melamine phosphate;

[0080] B: coating the insulating adhesive with a thickness of 60 μm on a release film, and removing the release film after baking and curing to obtain a hot melt adhesive film.

[0081] Specifically, the conventional method for testing the performance of hot melt adhesive films in the art was used to test the flame retardant effect, relative dielectric constant, loss factor, softening point and anti-sticking of the ultra-high-speed transmission hot melt adhesive films of Examples 1-3 and the traditional hot melt adhesive films for FFC of Comparative Examples 1-3. The flame retardant effect was determined by the vertical burning test method in the UL94 standard, and the flame retardant grades were divided into VTM-0, VTM-1, VTM-2 and HB from high to low. The corresponding test data are shown in Table 1 below. At the same time, the ultra-high-speed transmission hot melt adhesive films of Examples 1-3 and the traditional hot melt adhesive films for FFC of Comparative Examples 1-3 were pressed with conductors respectively, wherein the conductor specifications and pressing conditions were as follows:

[0082] Conductor specifications: 0.05mm thickness × 0.3mm width bare copper conductor, conductor spacing 0.5mm, line length 1000mm;

[0083] Pressing conditions: pressing temperature 195°C, pressure: 0.5MPa, speed: 1.0m / min;

[0084] After lamination under the above lamination conditions, the transmission performance of the wire was tested by laminating the shielding material of the same thickness using conventional testing methods in the art. The test results are shown in Table 1 below.

[0085] Table 1 Performance test results

[0086]

[0087] Table 1 Performance test results

[0088]

[0089] It can be seen from the data in Table 1 that the flame retardant effects of Examples 1-3 and Comparative Example 1 all meet the required standards. The relative dielectric constant of the hot melt adhesive film for FFC with ultra-high-speed transmission prepared in Examples 1-3 is 2.24-2.4, which is greater than the relative dielectric constant of the hot melt adhesive film of Comparative Example 1 and Comparative Example 3. The loss factor of the hot melt adhesive film for FFC with ultra-high-speed transmission prepared in Examples 1-3 is 0.00050575-0.00059145, which is less than the loss factor of Comparative Example 1 and Comparative Example 3. Moreover, relative to Comparative Example 1 and Comparative Example 2, the thermal conductivity of Examples 1-3 is 0.00050575-0.00059145. The hot melt adhesive film has low back adhesion, all less than <0.3N / 50mm, and a higher softening point, which can achieve the desired purpose of high temperature resistance. At the same time, the attenuation of Examples 1-3 after being pressed into FFC wires is reduced compared to Comparative Examples 1 and 3, and the corresponding transmission performance is improved. Moreover, the maximum eye diagram of the embodiments after being pressed into FFC wires is faster than that of Comparative Examples 1 and 3, that is, the maximum data transmission rate that the prepared FFC wire can support is faster. In summary, the hot melt adhesive film prepared by the present technical solution can achieve flame retardancy while having a high transmission rate and good transmission performance.

[0090] Compared with Example 2, Comparative Example 1 uses a modified polyolefin resin that has not been foamed, and its relative dielectric constant and low loss factor are not as good as those of the foamed polyolefin resin. On the basis of using the same amount of halogen-free flame retardant, the flame retardant effect of Comparative Example 1 is VTM-0, which is consistent with the flame retardant effect of Example 2, but the relative dielectric constant is 3.09, and the loss factor is 0.0117832, which is greater than the relative dielectric constant of 2.31 of Example 2, and much greater than the loss factor of 0.00054791 of Example 2, indicating that although the flame retardant effect is consistent, the transmission performance is not as good as that of Example 2. At the same time, the softening point of Comparative Example 1 is less than the softening point of Example 2, and the anti-stickiness is greater than the example group, indicating that the high temperature resistance is not as good as that of the example group. In short, compared with Example 2, although the flame retardant effect of Comparative Example 1 meets the standard, it is impossible to achieve good transmission performance while having the same good high temperature resistance.

[0091] Compared with Example 1, the added halogen-free flame retardant in Comparative Example 2 is not within the scope of the present technical solution. It can be seen from Table 1 that compared with Example 1, Comparative Example 1 has a lower relative dielectric constant and loss factor, and the attenuation and maximum eye diagram after being pressed into FFC wire are similar to those of the embodiment group, indicating that the transmission performance of Comparative Example 2 is better, but the flame retardant effect of the film of Comparative Example 2 is VTM-1, which does not meet the VTM-0 standard, and the softening point is 124°C, which is less than that of the embodiment group, and the anti-stickiness is 0.37, which is greater than that of the embodiment group, and the high temperature resistance is not as good as that of the embodiment group.

[0092] Compared with Example 1, in Comparative Example 3, in the foamed polyolefin resin used, the mass ratio of the modified polyolefin to the foaming agent is 100:1, which is not the mass ratio specified in the present technical solution. It can be seen from Table 1 that the flame retardant effect of the film of Comparative Example 3 is VTM-0, which meets the standard, and its softening point and anti-stickiness are both near the example group, indicating that Comparative Example 3 has better high temperature resistance, but the relative dielectric constant, loss factor and the maximum eye diagram after being pressed into FFC wire are all smaller than those of Example 1, indicating that Comparative Example 3 has the same high temperature resistance, but cannot achieve better transmission performance at the same time.

[0093] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A hot melt adhesive film for FFC with ultra-high-speed transmission, characterized in that: Made by coating insulating glue and then curing; Calculated by weight, the insulating adhesive includes 40-80 parts of toluene solvent, 20-40 parts of foamed polyolefin resin and 20-50 parts of halogen-free flame retardant; The foamed polyolefin resin comprises modified polyolefin, a foaming agent and a catalyst, and the mass ratio of the modified polyolefin to the foaming agent is 50:

1.

2. The hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 1, characterized in that: The molecular weight of the foamed polyolefin resin is greater than 150,000.

3. The method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 1, characterized in that: The main chain of the foamed polyolefin resin is styrene-butadiene-styrene copolymer.

4. The hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 1, characterized in that: The foaming agent is a carbonate foaming agent.

5. The hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 1, characterized in that: The halogen-free flame retardant is a phosphorus-nitrogen series flame retardant.

6. A method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission, for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to any one of claims 1 to 5, comprising the following steps: A: According to the formula of the insulating adhesive, a formulated amount of toluene solvent and a foamed polyolefin resin are mixed at a high speed, and after the foamed polyolefin resin is completely dissolved, a formulated amount of halogen-free flame retardant is added, and the mixture is evenly mixed to obtain the insulating adhesive; B: coating the insulating adhesive on a release film, and removing the release film after baking and curing to obtain the hot melt adhesive film for FFC with ultra-high-speed transmission.

7. The method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 6, characterized in that: The extrusion temperature for preparing the foamed polyolefin resin is 150-300° C., and the extrusion speed is 5-20 r / min.

8. The method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 6, characterized in that: In step A, the rotation speed of the high-speed mixing is 500-1200 r / min.

9. The method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 6, characterized in that: In step B, the coating thickness of the insulating adhesive is 10-300 μm.

10. The method for preparing a hot melt adhesive film for FFC with ultra-high-speed transmission according to claim 6, characterized in that: In step B, the release force of the release film is 50-100 gf.

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