Based on chemically resistant insulating paper

Abstract

This invention discloses a chemically resistant insulating paper, relating to the field of insulating materials technology. The chemically resistant insulating paper includes an outer layer, with an inner intermediate layer; the intermediate layer is bonded to the inner layer. This invention, combining a multi-layered composite structure with a unique fiber interweaving and porous structure, effectively blocks the penetration of chemical substances. The outer PTFE coating provides the first line of protection, the dense structure and chemically stable materials of the intermediate layer further block the penetration, and the modified fibers of the inner layer also possess a certain degree of corrosion resistance. Testing showed that after immersion in a 10% hydrochloric acid solution for 1000 hours, the insulating paper's performance did not significantly decrease. Each layer of material itself possesses excellent insulation properties, and the structural design optimizes the internal electric field distribution. The aramid fiber and nano-silica composite structure of the intermediate layer, and the modified cellulose and PPS fiber interweaving structure of the inner layer, reduce electron migration paths and improve insulation resistance, reaching over 10^15 Ω·cm.

Description

Technical Field

[0001] This utility model specifically relates to the field of insulating materials technology, and more specifically to insulating paper based on chemical corrosion resistance. Background Technology

[0002] In modern industrial production, the environments in which many electrical devices operate are increasingly complex, frequently facing corrosion from various chemical substances. Traditional insulating paper experiences a rapid decline in insulation and mechanical properties under chemically corrosive environments. For example, in chemical workshops, insulating paper is susceptible to corrosion from acid and alkali mists; on offshore platforms, it suffers from salt spray corrosion. This not only affects the normal operation of equipment but also poses safety hazards. Existing chemically resistant insulating papers are mostly achieved through improvements in raw materials, lacking effective innovation in structural design and failing to meet the demands of demanding applications. Therefore, developing an insulating paper with structural breakthroughs and superior chemical corrosion resistance is essential. Utility Model Content

[0003] The purpose of this invention is to provide a chemically resistant insulating paper that, through a unique structural design, can effectively resist chemical corrosion while possessing good electrical insulation and mechanical properties, thus meeting the needs of electrical equipment in complex industrial environments.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A chemically resistant insulating paper includes an outer layer, an inner layer thereof, and the inner layer thereof is further bonded to the inner layer.

[0006] The outer layer is a protective coating;

[0007] The intermediate layer is a reinforcement and barrier structure;

[0008] The inner layer is an insulating and supporting structure.

[0009] As a further technical solution of this utility model, the outer layer is a polytetrafluoroethylene coating.

[0010] As a further technical solution of this utility model, the intermediate layer is a fiber layer composed of aramid fiber and nano-silica.

[0011] As a further technical solution of this utility model, the inner layer is a fiber layer with good heat resistance and chemical stability.

[0012] As a further technical solution of this utility model, the intermediate layer is a mesh structure formed by aramid fibers interwoven in both longitudinal and transverse directions; nano-silica is embedded therein.

[0013] As a further technical solution of this utility model, the thickness of the outer layer is 0.05-0.2mm, the thickness of the middle layer is 0.3-0.8mm, and the thickness of the inner layer is 0.5-1.5mm.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model combines a multi-layered composite structure with a unique interwoven fiber and porous structure to effectively block the penetration of chemical substances. The outer PTFE coating provides the first line of protection, the dense structure and chemically stable materials of the middle layer further block the penetration, and the modified fibers of the inner layer also have a certain degree of corrosion resistance. Tests show that after soaking in a 10% hydrochloric acid solution for 1000 hours, the insulation paper's performance did not significantly decrease.

[0016] 2. In this invention, each layer of material possesses excellent insulation properties, and the structural design optimizes the internal electric field distribution. The aramid fiber and nano-silica composite structure in the middle layer, as well as the modified cellulose and PPS fiber interwoven structure in the inner layer, reduce electron migration paths and improve insulation resistance, reaching over 10^15 Ω·cm.

[0017] 3. In this invention, aramid fibers enhance the tensile and tear strength of the insulating paper, while the interwoven fiber structure and transition layer enhance the overall structural stability. The tensile strength can reach 120-200 MPa, and the tear strength is 6-12 kN / m, enabling it to withstand mechanical stress in complex environments.

[0018] 4. This utility model is applicable to the insulation of electrical equipment in industries such as chemical, marine, and pharmaceutical, and can also be used in fields such as electronic chip manufacturing where insulation and chemical corrosion resistance are extremely important, with huge market potential. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the structure of the intermediate layer of this utility model.

[0021] In the diagram: 1-outer layer, 2-middle layer, 3-inner layer. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1-2 In this embodiment of the utility model, an insulating paper based on chemical corrosion resistance includes an outer layer 1, an inner layer 2 on the inner side of the outer layer 1, the inner layer 2 being bonded to an inner layer 3, the outer layer 1 being a protective coating, the inner layer 2 being a reinforcing and barrier structure, and the inner layer 3 being an insulating and support structure.

[0024] In this embodiment, the outer layer 1 is a chemically resistant coating structure made of polytetrafluoroethylene (PTFE). PTFE has extremely low surface energy and excellent chemical stability, and hardly reacts with any chemical substances. The coating thickness is 0.05-0.2 mm, and it is uniformly applied to the surface of the insulating paper through spraying or impregnation processes. Its tight molecular structure forms a strong barrier, preventing the penetration of chemical substances and protecting the internal structure.

[0025] In this embodiment, the intermediate layer 2 is composed of aramid fibers and nano-silica. Aramid fibers possess high strength and high modulus, significantly enhancing the mechanical properties of the insulating paper, such as tensile strength and tear strength. The nano-silica particles, with a particle size between 5-50 nm, are uniformly dispersed among the aramid fibers. On one hand, the nano-silica fills the gaps between the fibers, making the structure more compact and reducing the channels for chemical penetration; on the other hand, its chemical stability also helps to enhance the overall chemical corrosion resistance. The thickness of this intermediate layer is 0.3-0.8 mm.

[0026] In this embodiment, the inner layer 3 is based on modified cellulose fibers with a certain proportion of polyphenylene sulfide (PPS) fibers added. The modified cellulose fibers are chemically treated to introduce chemically resistant groups, improving their corrosion resistance. PPS fibers have good heat resistance and chemical stability, and when interwoven with the modified cellulose fibers, they enhance insulation performance and structural stability. The inner layer thickness is 0.5-1.5 mm.

[0027] In this embodiment, a special three-dimensional interlacing process is employed during the fabrication of each fiber layer. Taking the middle layer as an example, aramid fibers interlace in both longitudinal and transverse directions to form a mesh structure, with nano-silica particles embedded within. This interlacing method increases the friction and bonding force between the fibers, making the structure more stable. Simultaneously, at the connection points with the outer PTFE coating and the inner insulating paper body, the fibers interpenetrate, further enhancing the interlayer bonding strength.

[0028] In this embodiment, a transition bonding layer is provided between the layers to strengthen the connection between them. The transition bonding layer uses an adhesive with good compatibility with the materials of the two adjacent layers, such as an epoxy resin adhesive containing active groups. The adhesive is cured under certain temperature and pressure to form a strong chemical bond, ensuring that the layers do not delaminate under chemical corrosion conditions.

[0029] As a further illustration of the above embodiments, by controlling the preparation process parameters, a specific distribution of micropores is formed inside the insulating paper. These pores are irregularly distributed in the direction perpendicular to the plane of the insulating paper, and the pore size gradually decreases from the outer layer to the inner layer. The outer layer pores have a larger diameter, ranging from 1 to 5 μm, which is used for initial adsorption and buffering of chemical substances; the inner layer pores have a diameter of 0.1 to 1 μm, reducing the possibility of chemical substances penetrating inward.

[0030] For larger pores, chemically stable inorganic nanoparticles, such as nano-calcium carbonate, are used as fillers. After filling, the pores are sealed with low-viscosity silicone resin. This ensures the air permeability of the insulating paper, which is beneficial for heat dissipation, while preventing chemical substances from penetrating the interior through the pores and damaging the insulation performance.

[0031] Preparation Example 1

[0032] Raw material preparation

[0033] Prepare a polytetrafluoroethylene emulsion for the preparation of an outer protective coating.

[0034] 100g of aramid fiber and 10g of nano-silica were used to uniformly disperse the nano-silica in the aramid fiber suspension using a high-speed stirring method, which was then used to make the intermediate layer.

[0035] 150g of modified cellulose fiber and 50g of polyphenylene sulfide fiber are mixed evenly to form the main material of the inner layer insulation paper.

[0036] Epoxy resin adhesives containing active groups are used for interlayer bonding.

[0037] Preparation process

[0038] Inner layer preparation: Modified cellulose fiber and polyphenylene sulfide fiber are mixed and formed under 0.3 MPa pressure through wet papermaking process to produce an inner layer insulating paper body with a thickness of 1 mm.

[0039] Intermediate layer preparation: A suspension of aramid fibers with dispersed nano-silica was formed by vacuum filtration under a pressure of 0.5 MPa to produce an intermediate reinforcement and barrier layer with a thickness of 0.5 mm.

[0040] Outer layer preparation: Polytetrafluoroethylene emulsion is uniformly coated onto the outer layer using a spraying process, with the coating thickness controlled at 0.1 mm.

[0041] Composite process: Apply epoxy resin adhesive evenly between each layer, and heat-press and cure at 120℃ and 1MPa pressure for 30 minutes to complete the composite of insulating paper.

[0042] Performance testing

[0043] Chemical corrosion resistance: After immersion in 15% sulfuric acid solution for 800 hours, the insulating paper showed no obvious corrosion and its performance was stable.

[0044] Electrical insulation performance: Insulation resistance reaches 1.2×10^15Ω・cm, and dielectric constant is 2.8 at 1MHz.

[0045] Mechanical properties: tensile strength is 150 MPa, tear strength is 8 kN / m.

[0046] Preparation Example 2

[0047] Raw material preparation

[0048] The outer protective coating was prepared by hot pressing using polytetrafluoroethylene powder.

[0049] 120g of aramid fiber and 15g of nano-silica were uniformly dispersed in the aramid fiber by ultrasonic dispersion.

[0050] 180g of modified cellulose fiber and 60g of polyphenylene sulfide fiber are used for the inner layer.

[0051] Another type of adhesive containing isocyanate groups is used for interlayer bonding.

[0052] Preparation process

[0053] Inner layer preparation: The mixed fibers are molded using a compression molding process to form an inner layer with a thickness of 1.2 mm under a pressure of 0.4 MPa and a temperature of 180°C.

[0054] Intermediate layer preparation: Dispersed aramid fibers and nano-silica are molded under a pressure of 0.6 MPa to form an intermediate layer with a thickness of 0.6 mm.

[0055] Outer layer preparation: Polytetrafluoroethylene powder was hot-pressed into an outer layer of 0.15 mm thickness at 250℃ and 2 MPa pressure.

[0056] Composite process: Apply adhesive between each layer, and heat-press and cure at 150℃ and 1.2MPa pressure for 40 minutes to complete the composite process.

[0057] Performance testing

[0058] Chemical corrosion resistance: The insulating paper maintains good performance after being immersed in a 10% sodium hydroxide solution for 1200 hours.

[0059] Electrical insulation performance: insulation resistance reaches 1.5×10^15Ω・cm, and dielectric constant is 2.6 at 1MHz.

[0060] Mechanical properties: tensile strength is 180 MPa, tear strength is 10 kN / m.

[0061] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0062] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An insulating paper based on chemical corrosion resistance, characterized in that: It includes an outer layer (1), and an inner layer (2) is provided on the inner side of the outer layer (1); the inner layer (2) is also bonded to the inner layer (3); The outer layer (1) is a protective coating; The intermediate layer (2) is a reinforcement and barrier structure; The inner layer (3) is an insulating and supporting structure.

2. The insulating paper based on chemical corrosion resistance according to claim 1, characterized in that: The outer layer (1) is a polytetrafluoroethylene coating.

3. The insulating paper based on chemical corrosion resistance according to claim 1, characterized in that: The inner layer (3) is a fiber layer with good heat resistance and chemical stability.

4. The insulating paper based on chemical corrosion resistance according to claim 1, characterized in that: The outer layer (1) has a thickness of 0.05-0.2 mm, the middle layer (2) has a thickness of 0.3-0.8 mm, and the inner layer (3) has a thickness of 0.5-1.5 mm.

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