A binder in a photovoltaic cell film screen protective film and a preparation method thereof
By using binders made of raw materials such as polyimide, the problems of large particle size of the binder, difficult to control the coating thickness, poor temperature resistance and low peel strength in the prior art, and a binder with high heat resistance, reliability and flame retardant performance are solved.
Patent Information
- Application Number
- CN202411887664.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-04-04
AI Technical Summary
The binder in the existing film screen protective film has problems such as large particle size and difficult to control the coating thickness, the epoxy resin has poor temperature resistance and the acrylic resin peeling strength is relatively low.
Polyimide (PAID) is used as the main resin, combined with phosphorus-based flame retardant, toughener and DMAC, and the binder is prepared by coating, and is dried, partially cross-linked and maturated.
It improves the heat resistance, reliability, ion migration resistance, weather resistance and flame retardant properties of the binder, and reduces the cost of equipment and raw materials.
Smart Images
Figure CN119752397A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of chemical materials, and in particular to an adhesive in a photovoltaic cell film screen protective film and a preparation method thereof. Background Art
[0002] Film screen protective film is a film material used to protect photolithography film negatives. It usually has good UV light resistance and excellent light transmittance, and has the functions of anti-scratch and anti-static, avoiding dust and increasing the service life of the film. It is mainly used in PCB negatives, LCD negatives, etc., to play a protective role and increase the service life of the film. It can adapt to the protection of different circuit films and glass chrome plates. In the field of photovoltaic cells, film screen protective film may be used to protect photovoltaic cells from damage during production, transportation and use, such as preventing scratches, stains or breakage. The binder in the film screen protective film is an important component of the protective film. Its function is to firmly adhere the protective film to the film screen to ensure that the film screen is protected from damage during processing, transportation and use.
[0003] Currently, the film screen protective films produced on the market are mainly of two types: epoxy resin covering film and acrylic resin covering film. Epoxy resin has large particle size, and the coating thickness is difficult to control, and it is not easy to reach the required thickness; after the thickness of acrylic resin is reduced, the peel strength is low, and its temperature resistance is poor. Summary of the invention
[0004] The purpose of the present invention is to provide a binder in a photovoltaic cell film screen protective film and a preparation method thereof, so as to solve the technical problems that the epoxy resin has large particle size, the coating thickness is difficult to control, and it is not easy to reach the corresponding required thickness; and after the thickness of the acrylic resin is reduced, the peel strength is low and its temperature resistance is poor.
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0006] The invention discloses a binder in a photovoltaic cell film screen protective film, which is prepared from the following raw materials in parts by weight: 50-70 parts of polyimide (PAID), 5-25 parts of a phosphorus-based flame retardant, 10 parts of a toughening agent, and 25 parts of DMAC.
[0007] Furthermore, it is made of the following raw materials in parts by weight: 65 parts of PAID, 10 parts of phosphorus-based flame retardant, 10 parts of toughening agent, and 25 parts of DMAC.
[0008] Furthermore, it is made of the following raw materials in parts by weight: 55 parts of PAID, 20 parts of phosphorus-based flame retardant, 10 parts of toughening agent, and 25 parts of DMAC.
[0009] Furthermore, it is made of the following raw materials in parts by weight: 60 parts of PAID, 15 parts of phosphorus-based flame retardant, 10 parts of toughening agent, and 25 parts of DMAC.
[0010] Furthermore, a method for preparing an adhesive in a photovoltaic cell film screen protective film includes: adding PAID, a phosphorus-based flame retardant, a toughening agent, and DMAC in sequence according to a formula, stirring for 5 hours, and preparing an adhesive solution with a solid content of 40%.
[0011] Furthermore, a method for preparing a binder in a photovoltaic cell film screen protective film also includes coating an adhesive solution on a PI film, controlling the dry adhesive thickness to be 3-10 μm, drying and partially cross-linking, and then placing the adhesive in an oven at 80° C. for 3 hours to obtain the binder.
[0012] Compared with the prior art, the present invention has the following beneficial effects:
[0013] The adhesive is prepared by using polyimide as the main resin, in combination with a phosphorus-based flame retardant, a toughening agent, and DMAC, and then by a coating method, thereby reducing the cost of equipment and raw materials. The prepared adhesive has good heat resistance and reliability, ion migration resistance, weather resistance, and flame retardancy. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 This is the result of dynamic thermomechanical analysis of adhesive and PI composite film.
[0015] Figure 2 Comb circuit used for ion migration resistance test.
[0016] Figure 3 This is the test result of the adhesive's ion migration resistance.
[0017] Figure 4 This is the adhesive peel strength test result diagram.
[0018] Figure 5 This is the flame retardant performance test result of the adhesive. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0020] Example 1
[0021] This embodiment discloses an adhesive in a photovoltaic cell film screen protective film of the present invention and a preparation method thereof. The adhesive is made of the following raw materials in parts by weight: 65 parts of PAID, 10 parts of a phosphorus-based flame retardant, 10 parts of a toughening agent, and 25 parts of DMAC. The preparation method is as follows: mixing according to the above formula, stirring for 5 hours, to obtain an adhesive solution with a solid content of 40%, and then coating the adhesive solution on a PI film, controlling the dry adhesive thickness to be 3-10 μm, drying, partially cross-linking, and then placing in an 80°C oven for aging for 3 hours to obtain the adhesive.
[0022] Example 2
[0023] This embodiment discloses an adhesive in a photovoltaic cell film screen protective film of the present invention and a preparation method thereof. The adhesive is made of the following raw materials in parts by weight: 55 parts of PAID, 20 parts of a phosphorus-based flame retardant, 10 parts of a toughening agent, and 25 parts of DMAC. The preparation method is as follows: mixing according to the above formula, stirring for 5 hours, to obtain an adhesive solution with a solid content of 40%, and then coating the adhesive solution on a PI film, controlling the dry adhesive thickness to be 3-10 μm, drying, partially cross-linking, and then placing in an 80°C oven for aging for 3 hours to obtain the adhesive.
[0024] Example 3
[0025] This embodiment discloses an adhesive in a photovoltaic cell film screen protective film of the present invention and a preparation method thereof. The adhesive is made of the following raw materials in parts by weight: 60 parts of PAID, 15 parts of a phosphorus-based flame retardant, 10 parts of a toughening agent, and 25 parts of DMAC. The preparation method is as follows: mixing according to the above formula, stirring for 5 hours, to obtain an adhesive solution with a solid content of 40%, and then coating the adhesive solution on a PI film, controlling the dry adhesive thickness to be 3-10 μm, drying, partially cross-linking, and then placing in an 80°C oven for aging for 3 hours to obtain the adhesive.
[0026] Test Case
[0027] The adhesive and binder prepared in Example 3 were tested for performance, and the results are as follows: Figure 1-5 The glass transition temperature of the adhesive was tested by dynamic mechanical analysis (DMA), and the test curve is shown in Figure 1 As shown. Figure 1It can be seen that the temperatures corresponding to the peak values of the dielectric loss factor (tanδ) are 180°C and 333°C, respectively, which are the glass transition temperature of the PAID adhesive and the glass transition temperature of the copper foil or copper plate, respectively. The glass transition temperature of the PAID adhesive is much higher than the epoxy resin adhesive and the acrylate adhesive (<100°C) used for the epoxy substrate. This indicates that the heat resistance and reliability of the adhesive of the present invention are better than those of the epoxy resin adhesive and the acrylate adhesive. The glass transition temperature of the adhesive can reflect the heat resistance of the adhesive to some extent. For a photovoltaic cell film screen protective film adhesive, the higher the glass transition temperature of the adhesive, the higher the heat resistance and reliability of the adhesive.
[0028] The insulation reliability of a photovoltaic cell film screen protective film adhesive is usually evaluated by ion migration resistance. Figure 2 The comb circuit shown in the figure tests the ion migration resistance of the adhesive. The line width / line spacing of the adhesive is 50μm / 50μm, and the power supply parameter is DC 12V. The sample is placed in a constant temperature and humidity chamber (temperature is 85℃, humidity is 85%RH) according to the path, and the resistance of the sample is tested at different times. The results are shown in Figure 3 As shown. Figure 3 It can be seen that the adhesive of the present invention has very high insulation reliability.
[0029] To evaluate the weather resistance of the adhesive, the peel strength of the adhesive after being treated in a "double 85" environment (temperature: 85°C, humidity: 85% RH) was tested. The test results are as follows: Figure 4 As shown. Before treatment, the peel strength of a photovoltaic cell film screen protective film adhesive was 1.28kgf / cm. After 240h treatment, the peel strength decreased, but still remained at a high level (1.06kgf / cm), meeting the use requirements of a photovoltaic cell film screen protective film adhesive. The weather resistance test results show that the adhesive with polyimide as the main resin has good resistance to moisture and heat aging and can be used in the preparation of a photovoltaic cell film screen protective film adhesive.
[0030] The flame retardant properties of the binder were tested by vertical combustion experiments. The test results are as follows: Figure 5 As shown. During the test, the flame extinguishing time was less than 1s, which indicates that the flame retardant grade of the adhesive reached UL94-V-0. The excellent flame retardant performance of the adhesive is closely related to the PAID resin (limiting oxygen index is 47%). The addition of reactive phosphorus flame retardants (DOPO, SPH-100) in the adhesive can further improve the flame retardant performance of the adhesive.
[0031] Table 1 is a table of test results of comprehensive properties of the adhesive. It can be seen from Table 1 that various properties of the adhesive of the present invention meet the IPC standard.
[0032]
[0033]
[0034] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. In other words, any changes or modifications made to the main design concept and spirit of the present invention that have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention in other related technical fields is also included in the patent protection scope of the present invention.
Claims
1. A binder in a photovoltaic cell film screen protective film, characterized in that: The invention is prepared from the following raw materials in parts by weight: 50-70 parts of polyimide (PAID), 5-25 parts of phosphorus-based flame retardant, 10 parts of toughening agent and 25 parts of DMAC.
2. The adhesive in the photovoltaic cell film screen protective film according to claim 1, characterized in that: The invention is made of the following raw materials in parts by weight: 65 parts of PAID, 10 parts of phosphorus flame retardant, 10 parts of toughening agent and 25 parts of DMAC.
3. The adhesive in the photovoltaic cell film screen protective film according to claim 1, characterized in that: The invention is made of the following raw materials in parts by weight: 55 parts of PAID, 20 parts of phosphorus flame retardant, 10 parts of toughening agent and 25 parts of DMAC.
4. The adhesive in the photovoltaic cell film screen protective film according to claim 1, characterized in that: The invention is made of the following raw materials in parts by weight: 60 parts of PAID, 15 parts of phosphorus-based flame retardant, 10 parts of toughening agent and 25 parts of DMAC.
5. A method for preparing a binder in a photovoltaic cell film screen protective film according to any one of claims 1 to 4, characterized in that: include: PAID, phosphorus flame retardant, toughening agent and DMAC were added in sequence according to the formula and stirred for 5 hours to obtain an adhesive solution with a solid content of 40%.
6. The method for preparing a binder in a photovoltaic cell film screen protective film according to claim 5, characterized in that: The method also includes coating the adhesive solution on the PI film, controlling the dry adhesive thickness to be 3-10 μm, drying and partially cross-linking, and then placing the film in an oven at 80° C. for aging for 3 hours to obtain the adhesive.