A flame retardant FDC acquisition circuit and its preparation method and application

Abstract

The present invention belongs to the technical field of battery collection circuit components, and discloses a flame retardant FDC collection circuit and its preparation method and application. The flame retardant FDC collection circuit includes an intermediate copper circuit layer and upper and lower packaging film layers, and at least one layer between the intermediate copper circuit layer and the upper and lower packaging film layers is provided with a thermosetting flame retardant adhesive layer. The thermosetting flame retardant adhesive layer is prepared by the following method: terephthalic acid or p-phenylenediamine is reacted with ethyl isocyanate acrylate to obtain a cross-linking monomer, and then copolymerized with acrylic acid monomer and acrylate monomer to obtain a modified acrylic resin, and then mixed with epoxy resin and heated to react, and a flame retardant and a curing agent are added to mix to obtain a flame retardant adhesive liquid; the obtained flame retardant adhesive liquid is coated on the packaging film layer, and a thermosetting flame retardant adhesive layer is obtained after curing. The present invention adopts a specific thermosetting flame retardant adhesive layer to achieve the flame retardant and high temperature resistant effect of the FDC collection circuit, and reduce the risk of fire and combustion of the battery pack.

Description

Technical Field

[0001] The invention belongs to the technical field of battery collection circuit components, and in particular relates to a flame retardant FDC collection circuit and a preparation method and application thereof. Background Art

[0002] With the rapid development of new energy vehicles, energy storage and other industries, the CCS integrated busbar market has also expanded rapidly. At the same time, with the advancement of battery integration technology and the increase in automation demand for large-scale production, the CCS of the traditional wiring harness solution has gradually been replaced by the integrated and lightweight FPC (Flexible Printed Circuit) solution. In addition, compared with the FPC solution, the more cost-effective FFC (Flexible Flat Cable) and FDC (Flexible Die Cutting Circuit) solutions are also being continuously promoted. The traditional wiring harness + injection molding bracket solution has lower cost and good stability, but requires manual assembly and has a low degree of automation, which is not conducive to mass production. Compared with the wiring harness solution, the CCS integrated busbar using FPC / FFC + blister board, or hot pressing solution, has a light and regular structure and high integration, which is conducive to improving the space utilization and assembly efficiency of the battery pack, and is in line with the trend of lightweight automobiles, system integration of components and large modules.

[0003] However, due to the complex working conditions of the battery pack, there is currently no mature technology in the industrial technology field to completely avoid thermal runaway of the battery cell. When the battery cell experiences thermal runaway, the explosion-proof valve will start working to release the high-temperature and high-pressure gas in the battery cell. The temperature of this high-temperature and high-pressure gas often reaches above 500°C. Although the CCS products currently on the market are all made of flame-retardant materials, the organic film covering the surface of the acquisition circuit (such as FPC) has a temperature resistance level of only 150°C (PET) or 250°C (PI). When encountering a high temperature of 500°C, it will soften, fluidize, and shrink and deform, which will cause the copper circuit of the acquisition circuit to become less fixed. Once the copper circuit is overlapped, a short circuit will occur, causing the entire battery pack to burn uncontrollably and violently, resulting in significant property and personal safety losses.

[0004] In our previous patent CN116505204A, flame retardant sheets such as mica sheets, flexible ceramic sheets, Mylar sheets or fireproof paper are glued on the film layer to achieve flame retardant effect and improve circuit stability and safety. However, the method of gluing flame retardant sheets increases the battery pack assembly process on the one hand, and on the other hand, the adhesion stability of the flame retardant sheets is poor, and the close fit with the collection circuit components is poor, and the battery cell is easy to delaminate when thermal runaway occurs, and the flame retardant reliability needs to be further improved.

[0005] Therefore, developing an acquisition circuit suitable for new energy battery signal acquisition, which has a simple preparation process and low cost and is stable, flame retardant and high temperature resistant has good application prospects. Summary of the invention

[0006] In view of the above shortcomings and deficiencies in the prior art, the primary purpose of the present invention is to provide a flame retardant FDC acquisition circuit.

[0007] Another object of the present invention is to provide a method for preparing the flame-retardant FDC acquisition circuit.

[0008] Another object of the present invention is to provide an application of the flame-retardant FDC acquisition circuit in a battery module acquisition integrated component.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A flame retardant FDC acquisition circuit, comprising an intermediate copper circuit layer and upper and lower packaging film layers, wherein at least one layer between the intermediate copper circuit layer and the upper and lower packaging film layers is provided with a thermosetting flame retardant adhesive layer;

[0011] The thermosetting flame retardant adhesive layer is prepared by the following method:

[0012] (1) adding terephthalic acid or p-phenylenediamine and ethyl isocyanate acrylate to an ethyl acetate solvent and heating and stirring to react to obtain a crosslinking monomer solution;

[0013] (2) mixing the cross-linking monomer solution obtained in step (1) with acrylic acid monomer and acrylic ester monomer, adding ethyl acetate solvent to dilute, deoxygenating with nitrogen, adding an initiator, heating and performing copolymerization reaction to obtain a modified acrylic resin solution;

[0014] (3) mixing the modified acrylic resin solution obtained in step (2) with the epoxy resin, heating the mixture for reaction, cooling the mixture to room temperature, adding a flame retardant and a curing agent, and mixing the mixture to obtain a flame retardant adhesive solution;

[0015] (4) applying the flame retardant adhesive liquid obtained in step (3) to the encapsulation adhesive film layer, and obtaining a thermosetting flame retardant adhesive layer after curing.

[0016] Furthermore, in step (1), the molar ratio of terephthalic acid or p-phenylenediamine to ethyl isocyanate acrylate is 1:2.

[0017] Furthermore, when the reaction raw material in step (1) is terephthalic acid, dibutyltin dilaurate is also added as a catalyst, and the temperature of the heating and stirring reaction is 60 to 90°C; when the reaction raw material is p-phenylenediamine, the temperature of the heating and stirring reaction is 30 to 60°C.

[0018] Furthermore, the acrylic acid monomer in step (2) is one or a mixture of acrylic acid and methacrylic acid; the acrylic acid ester monomer is at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, butyl acrylate, butyl methacrylate, isooctyl acrylate, and isooctyl methacrylate.

[0019] Furthermore, in step (2), the mass ratio of the cross-linking monomer to the acrylic acid monomer and the acrylic ester monomer in the cross-linking monomer solution is 0.05-0.3:1-2:1-2.

[0020] Furthermore, the amount of ethyl acetate solvent added for dilution in step (2) is such that the solid content of the reaction system is 30% to 50%; the initiator is azobisisobutyronitrile or azobisisoheptanenitrile; and the temperature for heating the copolymerization reaction is 60 to 80°C.

[0021] Furthermore, the epoxy resin in step (3) is bisphenol A epoxy resin or bisphenol F epoxy resin; and the mass ratio of the modified acrylic resin to the epoxy resin contained in the modified acrylic resin solution is 2-4:1-2.

[0022] Furthermore, the temperature of the heating reaction in step (3) is 40-60° C., and the heating reaction time is 0.5-3 hours. The heating reaction allows a portion of the epoxy groups of the epoxy resin to undergo a grafting reaction with the acrylic acid segments in the modified acrylic resin, thereby improving the compatibility stability of the mixed adhesive and enhancing the bonding and curing effect of the flame retardant adhesive.

[0023] Furthermore, the flame retardant in step (3) is one or more of diethyl aluminum phosphinate, hexaphenoxy cyclotriphosphazene, and ammonium polyphosphate; the amount of the flame retardant added is 0.25 to 4 times the total mass of the modified acrylic resin and the epoxy resin.

[0024] Furthermore, the curing agent in step (3) is one or more of 4,4'-diaminodiphenyl sulfone, dicyandiamide, acid anhydride, imidazole, HDI, TDI, and melamine; and the amount of the curing agent added is 0.05 to 1 times the total mass of the modified acrylic resin and the epoxy resin.

[0025] Furthermore, in step (4), the mixed adhesive solution is coated on the packaging adhesive film layer using a roll-to-roll process.

[0026] Furthermore, the upper and lower packaging film layers are PET (polyester) or PI (polyimide) films.

[0027] Furthermore, the thickness of the upper and lower packaging film layers is 0.03-0.5 mm, and the thickness of the thermosetting flame-retardant adhesive layer is 0.05-1 mm.

[0028] The method for preparing the flame retardant FDC acquisition circuit comprises the following steps:

[0029] The copper foil is die-cut and shaped, and then a packaging adhesive film layer coated with a flame-retardant adhesive liquid is used for hot-pressing packaging and curing to obtain a flame-retardant FDC collection circuit.

[0030] The above-mentioned flame-retardant FDC acquisition circuit is used in the battery module acquisition integrated component.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention provides a thermosetting flame-retardant adhesive layer between the copper circuit layer and the encapsulation film layer of the FDC acquisition circuit, thereby achieving tight bonding and fixation between the copper circuit layer and the encapsulation film layer, while achieving flame retardant and high temperature resistant effects, effectively reducing the overlapping short circuit ignition of the copper circuit during thermal runaway of the battery cell, and reducing the risk of fire and combustion of the battery pack.

[0033] (2) The invention further adopts a modified thermosetting resin system of modified acrylic resin and epoxy resin, which has good thermosetting effect and bonding effect; by using specific cross-linking monomers to copolymerize and cross-link the acrylic resin, on the one hand, the cohesive strength of the resin can be improved, and on the other hand, the bonding strength with the packaging film can be improved, and the bonding strength between the flame retardant adhesive layer and the packaging film and the copper circuit can be improved, so as to achieve the bonding and hot pressing packaging and fixing of the copper circuit under the condition of high flame retardant addition, and finally improve the structural stability and flame retardant effect of the FDC collection circuit.

[0034] (3) The flame-retardant FDC acquisition circuit provided with a thermosetting flame-retardant adhesive layer of the present invention can be produced by a roll-to-roll process. Compared with the conventional high-temperature resistant and insulating flame-retardant sheet composite solution, it has the advantages of high reliability, high production efficiency, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the overall structure of a flame-retardant FDC acquisition circuit in an embodiment;

[0036] Figure 2 It is a schematic diagram of the stacked structure of a flame-retardant FDC acquisition circuit in an embodiment. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] A flame retardant FDC acquisition circuit, the overall structure diagram and the stacked structure diagram are respectively as shown in Figure 1 and Figure 2 It comprises a middle copper circuit layer and upper and lower packaging film layers, wherein a thermosetting flame retardant adhesive layer is arranged between the middle copper circuit layer and the upper and lower packaging film layers.

[0040] The flame retardant FDC acquisition circuit is prepared by the following method:

[0041] (1) Add terephthalic acid, ethyl isocyanate acrylate and catalyst dibutyltin dilaurate to ethyl acetate solvent and heat and stir to react. The molar ratio of terephthalic acid to ethyl isocyanate acrylate is 1:2, the amount of catalyst added is 0.4% of the mass of the polymerized monomer, the temperature of the heating and stirring reaction is 85° C., and the reaction time is 3 hours to obtain a cross-linking monomer solution.

[0042] (2) The cross-linking monomer solution obtained in step (1) (based on the cross-linking monomer content) is mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.15:1:2, and then ethyl acetate is added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile is added, and the mixture is heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0043] (3) The modified acrylic resin solution obtained in step (2) (40 parts by solid content) was mixed with bisphenol A epoxy resin (E-44, 20 parts by solid content), heated to 50° C. for reaction for 1 hour, then cooled to room temperature, 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0044] (4) The flame retardant adhesive obtained in step (3) is coated on a 0.3 mm thick PET packaging adhesive film through a roll-to-roll process. The thickness of the flame retardant adhesive coating is 0.5 mm, so as to obtain a PET packaging adhesive film coated with a flame retardant adhesive layer.

[0045] (5) After the copper foil is die-cut and shaped, it is hot-pressed and packaged with a PET packaging film coated with a flame-retardant adhesive layer to obtain a flame-retardant FDC collection circuit.

[0046] Example 2

[0047] A flame retardant FDC acquisition circuit comprises a middle copper circuit layer and upper and lower packaging film layers, wherein a thermosetting flame retardant adhesive layer is arranged between the middle copper circuit layer and the upper packaging film layer.

[0048] The flame retardant FDC acquisition circuit is prepared by the following method:

[0049] (1) Add terephthalic acid, ethyl isocyanate acrylate and catalyst dibutyltin dilaurate to ethyl acetate solvent and heat and stir to react. The molar ratio of terephthalic acid to ethyl isocyanate acrylate is 1:2, the amount of catalyst added is 0.4% of the mass of the polymerized monomer, the temperature of the heating and stirring reaction is 75° C., and the reaction time is 4 hours to obtain a cross-linking monomer solution.

[0050] (2) The cross-linking monomer solution obtained in step (1) (based on the cross-linking monomer content) is mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.05:1:1, and then ethyl acetate is added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile is added, and the mixture is heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0051] (3) The modified acrylic resin solution obtained in step (2) (30 parts by solid content) was mixed with bisphenol A epoxy resin (E-44, 30 parts by solid content), heated to 40°C for reaction for 3 hours, and then cooled to room temperature. 100 parts of flame retardant hexaphenoxy cyclotriphosphazene and 20 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0052] (4) The flame retardant adhesive obtained in step (3) is coated on a 0.4 mm thick PET packaging film through a roll-to-roll process. The thickness of the flame retardant adhesive coating is 0.6 mm, thereby obtaining a PET packaging film coated with a flame retardant adhesive layer.

[0053] (5) After the copper foil is die-cut and shaped, a PET packaging film coated with a flame-retardant adhesive layer is used as an upper packaging film layer and an ordinary PET film is used as a lower packaging film layer for hot pressing packaging and curing to obtain a flame-retardant FDC collection circuit.

[0054] Example 3

[0055] A flame retardant FDC acquisition circuit comprises a middle copper circuit layer and upper and lower packaging film layers, wherein a thermosetting flame retardant adhesive layer is arranged between the middle copper circuit layer and the lower packaging film layer.

[0056] The flame retardant FDC acquisition circuit is prepared by the following method:

[0057] (1) Add terephthalic acid, ethyl isocyanate acrylate and catalyst dibutyltin dilaurate to ethyl acetate solvent and heat and stir to react. The molar ratio of terephthalic acid to ethyl isocyanate acrylate is 1:2, the amount of catalyst added is 0.4% of the mass of the polymerized monomer, the temperature of the heating and stirring reaction is 70° C., and the reaction time is 5 hours to obtain a cross-linking monomer solution.

[0058] (2) The cross-linking monomer solution obtained in step (1) (based on the cross-linking monomer content) is mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.3:2:1, and then ethyl acetate is added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile is added, and the mixture is heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0059] (3) The modified acrylic resin solution obtained in step (2) (60 parts by solid content) and bisphenol F epoxy resin (20 parts by solid content) are mixed and heated to 60° C. for reaction for 0.5 h, then cooled to room temperature, 50 parts by flame retardant ammonium polyphosphate and 5 parts by curing agent dicyandiamide are added and mixed to obtain a flame retardant adhesive.

[0060] (4) The flame retardant adhesive obtained in step (3) is coated on a 0.5 mm thick PET packaging film through a roll-to-roll process. The thickness of the flame retardant adhesive coating is 0.8 mm, thereby obtaining a PET packaging film coated with a flame retardant adhesive layer.

[0061] (5) After the copper foil is die-cut and shaped, a PET packaging film coated with a flame-retardant adhesive layer is used as a lower packaging film layer and an ordinary PET film is used as an upper packaging film layer for hot pressing packaging and curing to obtain a flame-retardant FDC collection circuit.

[0062] Example 4

[0063] A flame retardant FDC acquisition circuit, the overall structure diagram and the stacked structure diagram are respectively as shown in Figure 1 and Figure 2 It comprises a middle copper circuit layer and upper and lower packaging film layers, wherein a thermosetting flame retardant adhesive layer is arranged between the middle copper circuit layer and the upper and lower packaging film layers.

[0064] The flame retardant FDC acquisition circuit is prepared by the following method:

[0065] (1) Add p-phenylenediamine and ethyl isocyanate acrylate to ethyl acetate solvent and heat and stir to react. The molar ratio of p-phenylenediamine to ethyl isocyanate acrylate is 1:2, the temperature of the heating and stirring reaction is 40° C., and the reaction time is 0.5 h to obtain a crosslinking monomer solution.

[0066] (2) The cross-linking monomer solution obtained in step (1) (based on the cross-linking monomer content) is mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.15:1:2, and then ethyl acetate is added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile is added, and the mixture is heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0067] (3) The modified acrylic resin solution obtained in step (2) (40 parts by solid content) was mixed with bisphenol A epoxy resin (E-44, 20 parts by solid content), heated to 50° C. for reaction for 1 hour, then cooled to room temperature, 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0068] (4) The flame retardant adhesive obtained in step (3) is coated on a 0.3 mm thick PI packaging film through a roll-to-roll process. The thickness of the flame retardant adhesive coating is 0.5 mm, and a PI packaging film coated with a flame retardant adhesive layer is obtained.

[0069] (5) After the copper foil is die-cut and shaped, it is hot-pressed and packaged with a PI packaging film coated with a flame-retardant adhesive layer to obtain a flame-retardant FDC collection circuit.

[0070] Comparative Example 1

[0071] In the preparation method of a flame retardant adhesive in this comparative example, compared with Example 1, the bonding resin uses a single epoxy resin, which is prepared by the following method:

[0072] Bisphenol A epoxy resin (E-44, 60 parts by solid content) was mixed with 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone at room temperature to obtain a flame retardant adhesive.

[0073] Comparative Example 2

[0074] In the preparation method of a flame retardant adhesive in this comparative example, compared with Example 1, the modified acrylic resin solution is not pre-heated with the epoxy resin for modification reaction, and is prepared by the following method:

[0075] The modified acrylic resin solution obtained in step (2) of Example 1 (40 parts by solid content) and bisphenol A epoxy resin (E-44, 20 parts by solid content) were mixed at room temperature with 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone to obtain a flame retardant adhesive.

[0076] Comparative Example 3

[0077] The preparation method of a flame retardant adhesive in this comparative example is, compared with Example 1, no crosslinking monomer is added in the preparation of the modified acrylic resin, and the modified acrylic resin is prepared by the following method:

[0078] (1) Methacrylic acid and butyl acrylate were mixed in a mass ratio of 1:2, and then ethyl acetate was added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile was added, and the mixture was heated to 75° C. for copolymerization for 4 hours to obtain an acrylic resin solution.

[0079] (2) The acrylic resin solution obtained in step (1) (40 parts by solid content) and bisphenol A epoxy resin (E-44, 20 parts by solid content) were mixed and heated to 50° C. for reaction for 1 hour, then cooled to room temperature, 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0080] Comparative Example 4

[0081] In the preparation method of a flame retardant adhesive in this comparative example, compared with Example 1, the modified acrylic resin is prepared by using conventional ethylene glycol dimethacrylate (EGDMA) crosslinking agent, which is prepared by the following method:

[0082] (1) A crosslinking monomer ethylene glycol dimethacrylate (EGDMA) was mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.15:1:2, and then an ethyl acetate solvent was added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile was added, and the mixture was heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0083] (2) The modified acrylic resin solution obtained in step (1) (40 parts by solid content) and bisphenol A epoxy resin (E-44, 20 parts by solid content) were mixed and heated to 50° C. for reaction for 1 hour, then cooled to room temperature, 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0084] Comparative Example 5

[0085] In the preparation method of a flame retardant adhesive of this comparative example, compared with Example 4, aliphatic diamine 1,6-hexanediamine is used to replace p-phenylenediamine to prepare the crosslinking monomer, and the specific preparation steps are as follows:

[0086] (1) Add 1,6-hexanediamine and ethyl isocyanate acrylate to ethyl acetate solvent and heat and stir to react. The molar ratio of 1,6-hexanediamine to ethyl isocyanate acrylate is 1:2, the temperature of the heating and stirring reaction is 40° C., and the reaction time is 0.5 h to obtain a crosslinking monomer solution.

[0087] (2) The cross-linking monomer solution obtained in step (1) (based on the cross-linking monomer content) is mixed with methacrylic acid and butyl acrylate in a mass ratio of 0.15:1:2, and then ethyl acetate is added to dilute the mixture to a solid content of 40%. After deoxygenation with nitrogen, an initiator azobisisobutyronitrile is added, and the mixture is heated to 75° C. for copolymerization for 4 hours to obtain a modified acrylic resin solution.

[0088] (3) The modified acrylic resin solution obtained in step (2) (40 parts by solid content) was mixed with bisphenol A epoxy resin (E-44, 20 parts by solid content), heated to 50° C. for reaction for 1 hour, then cooled to room temperature, 60 parts of flame retardant aluminum diethylphosphinate and 10 parts of curing agent 4,4'-diaminodiphenyl sulfone were added and mixed to obtain a flame retardant adhesive.

[0089] The peel strength (in Example 1 and Comparative Examples 1 to 4, the flame retardant adhesive was coated on the PET base film and hot-pressed and cured, and then a 180° peel force test was performed; in Example 4 and Comparative Example 5, the flame retardant adhesive was coated on the PI base film and hot-pressed and cured, and then a 180° peel force test was performed), mechanical properties (after the flame retardant adhesive liquid was dried to form a film, the tensile strength was tested using a universal mechanical testing machine) and heat resistance (the flame retardant adhesive was used for composite bonding of two pieces of glass fiber cloth, and after hot-pressing and curing, it was placed in a 300°C oven and baked for 5 minutes to observe whether debonding and cracking occurred) of the flame retardant adhesive obtained in the above Example 1 and Example 4 and Comparative Examples 1 to 5 were tested, and the results are shown in Table 1 below.

[0090] Table 1

[0091]

[0092]

[0093] It can be seen from the comparison results of Example 1 and Comparative Example 1 that the flame retardant adhesive of the present invention uses a mixture of modified acrylic resin and epoxy resin as a bonding resin, which can significantly improve the bonding force and strength of the flame retardant adhesive compared with the single epoxy resin. It can be seen from the comparison results of Example 1 and Comparative Example 2 that the bonding force and strength of the flame retardant adhesive can be significantly improved by reacting the modified acrylic resin with the epoxy resin in advance. It can be seen from the comparison results of Example 1 and Comparative Example 3 that the preparation of modified acrylic resin can significantly improve the bonding force and strength of the flame retardant adhesive by introducing a specific cross-linking monomer. It can be seen from the comparison results of Example 1 and Comparative Examples 3 to 4 that the introduction of conventional cross-linking monomers in the preparation of modified acrylic resin can improve the mechanical strength of the flame retardant adhesive, but has an adverse effect on the bonding force. It can be seen from the comparison results of Example 4 and Comparative Example 5 that the bonding force and strength of the flame retardant adhesive obtained by using p-phenylenediamine to prepare the cross-linking monomer is significantly improved compared with linear aliphatic diamine.

[0094] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A flame retardant FDC acquisition circuit, characterized in that: It comprises an intermediate copper circuit layer and upper and lower packaging film layers, wherein at least one layer between the intermediate copper circuit layer and the upper and lower packaging film layers is provided with a thermosetting flame retardant adhesive layer; The thermosetting flame retardant adhesive layer is prepared by the following method: (1) adding terephthalic acid or p-phenylenediamine and ethyl isocyanate acrylate to an ethyl acetate solvent and heating and stirring to react to obtain a crosslinking monomer solution; (2) mixing the cross-linking monomer solution obtained in step (1) with acrylic acid monomer and acrylic ester monomer, adding ethyl acetate solvent to dilute, deoxygenating with nitrogen, adding an initiator, heating and performing copolymerization reaction to obtain a modified acrylic resin solution; (3) mixing the modified acrylic resin solution obtained in step (2) with the epoxy resin, heating the mixture for reaction, cooling the mixture to room temperature, adding a flame retardant and a curing agent, and mixing the mixture to obtain a flame retardant adhesive solution; (4) applying the flame retardant adhesive liquid obtained in step (3) to the encapsulation adhesive film layer, and curing the encapsulation adhesive film layer to obtain a thermosetting flame retardant adhesive layer; The molar ratio of terephthalic acid or p-phenylenediamine to ethyl isocyanate acrylate in step (1) is 1:

2.

2. A flame retardant FDC acquisition circuit according to claim 1, characterized in that: In step (1), when the reaction raw material is terephthalic acid, dibutyltin dilaurate is also added as a catalyst, and the temperature of the heating and stirring reaction is 60-90°C; when the reaction raw material is p-phenylenediamine, the temperature of the heating and stirring reaction is 30-60°C.

3. A flame retardant FDC acquisition circuit according to claim 1, characterized in that: The acrylic acid monomer in step (2) is one or a mixture of acrylic acid and methacrylic acid; the acrylic acid ester monomer is at least one of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, butyl acrylate, butyl methacrylate, isooctyl acrylate, and isooctyl methacrylate.

4. A flame retardant FDC acquisition circuit according to claim 1, characterized in that: The mass ratio of the cross-linking monomer to the acrylic acid monomer and the acrylic ester monomer in the cross-linking monomer solution in step (2) is 0.05-0.3:1-2:1-2.

5. The flame retardant FDC acquisition circuit according to claim 1, characterized in that: The amount of ethyl acetate solvent added for dilution in step (2) is such that the solid content of the reaction system is 30% to 50%; the initiator is azobisisobutyronitrile or azobisisoheptanenitrile; and the temperature for heating the copolymerization reaction is 60 to 80°C.

6. The flame retardant FDC acquisition circuit according to claim 1, characterized in that: The epoxy resin in step (3) is bisphenol A epoxy resin or bisphenol F epoxy resin; the mass ratio of the modified acrylic resin to the epoxy resin contained in the modified acrylic resin solution is 2-4:1-2; the temperature of the heating reaction is 40-60° C., and the heating reaction time is 0.5-3 h.

7. The flame retardant FDC acquisition circuit according to claim 1, characterized in that: The flame retardant in step (3) is one or more of diethyl aluminum phosphinate, hexaphenoxy cyclotriphosphazene, and ammonium polyphosphate; the amount of the flame retardant added is 0.25 to 4 times the total mass of the modified acrylic resin and the epoxy resin; the curing agent is one or more of 4,4'-diaminodiphenyl sulfone, dicyandiamide, acid anhydride, imidazole, HDI, TDI, and melamine; the amount of the curing agent added is 0.05 to 1 times the total mass of the modified acrylic resin and the epoxy resin.

8. The flame retardant FDC acquisition circuit according to claim 1, characterized in that: In step (4), the flame retardant adhesive solution is coated on the packaging film layer using a roll-to-roll process.

9. The flame retardant FDC acquisition circuit according to claim 1, characterized in that: The upper and lower packaging film layers are PET or PI films; the thickness of the upper and lower packaging film layers is 0.03-0.5 mm, and the thickness of the thermosetting flame retardant adhesive layer is 0.05-1 mm.

10. A method for preparing a flame retardant FDC acquisition circuit according to any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: The copper foil is die-cut and shaped, and then a packaging adhesive film layer coated with a flame-retardant adhesive liquid is used for hot-pressing packaging and curing to obtain a flame-retardant FDC collection circuit.

11. Application of a flame retardant FDC acquisition circuit as claimed in any one of claims 1 to 9 in a battery module acquisition integrated component.

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