Flame-retardant flexible cable

Abstract

The invention relates to the technical field of cables, and discloses a flame-retardant flexible cable which comprises a core body, a wear-resistant layer, a self-repairing hierarchical structure, an insulating layer and a connecting layer. The self-repairing hierarchical structure has the characteristics of automatic fusion and closing, and a fluorescent agent is mixed in the self-repairing hierarchical structure, so that the self-repairing hierarchical structure can emit light at night and is convenient for maintenance personnel to quickly identify damaged parts. The insulating layer provides additional protection, and the connecting layer keeps each layer stable; the self-repairing hierarchical structure is separated through the design of the division blocks, mutual influence is avoided, cable cutting is facilitated, the formula of the self-repairing hierarchical structure comprises polyether polyol, TDI, an organic tin catalyst, acetone, zinc sulfide fluorescent powder and cadmium sulfide fluorescent powder, and the self-repairing hierarchical structure is separated through the design of the division blocks, so that mutual influence is avoided; the cable has the self-healing capability, the fire hazard problem can be avoided, the service life of the cable can be prolonged due to the existence of the self-repairing hierarchical structure and the wear-resistant layer, and the replacement and maintenance cost caused by wear and damage can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cables, in particular to a flame-retardant flexible cable. Background Art

[0002] The product standard adopted for flame-retardant cables is GB31247-2014 "Classification of Combustion Performance of Electrical Cables and Optical Cables". In this standard, flame-retardant cables are also called "flame-retardant Grade 1 cables".

[0003] Flame retardant cables are usually designed with special materials and structures to improve their fire resistance. These cables can maintain the integrity of the circuit when a fire occurs, providing a certain amount of time for personnel evacuation and fire rescue.

[0004] One of the main functions of the protective layer of the flexible cable is to provide fire protection. If the protective layer is damaged, the insulation material and conductor inside the cable are more likely to be exposed to external fire sources, reducing the fire resistance of the cable and increasing the risk of fire.

[0005] At the same time, the damaged protective layer allows the flammable materials inside the cable, such as insulation materials, to directly contact the air or other flammable substances, which increases the possibility of fire because flammable materials are more easily ignited;

[0006] In addition, damage to the protective layer may cause a short circuit or arc between the conductors inside the cable. Short circuits and arcs will generate high temperatures and sparks, leading to fires.

[0007] According to the "A photothermal effect self-repairing cable insulation material and preparation method" proposed in CN108003604A, a high-pressure mercury lamp / high-intensity metal halide lamp / short-arc xenon lamp is used in the preparation process of the self-repairing cable insulation material. Ultraviolet light irradiation is carried out through the above equipment to polymerize the UV elastic resin precursor and form a coating layer on the surface of the doped polyaniline nanomaterial.

[0008] However, the ultraviolet intensity under natural conditions is usually low and cannot provide the same irradiation conditions as in the experiment; therefore, although the material exhibits self-healing properties under experimental conditions, the possibility of achieving self-healing under natural conditions is low.

[0009] Moreover, after the cable self-repairs, its strength becomes lower and its wear resistance becomes worse. Although it can provide fire protection and leakage protection in a short period of time, the overall protection performance is reduced and further repair and maintenance by maintenance personnel are required. However, since the cables are generally laid over long distances, maintenance personnel cannot find damaged parts in time, affecting maintenance efficiency.

[0010] Therefore, we propose a flame retardant flexible cable to solve the above problems. Summary of the invention

[0011] The object of the present invention is to provide a flame retardant flexible cable to solve the problems raised in the above background technology.

[0012] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0013] A flame-retardant flexible cable comprises a core body, a wear-resistant layer is arranged on the outside of the core body, and a self-repairing hierarchical structure is arranged between the wear-resistant layer and the core body;

[0014] The self-repairing hierarchical structure includes a flame-retardant TPU layer and an adhesive mixed with a fluorescent agent, wherein the ingredients of the adhesive are: 45% epoxy resin, 13% polyurethane, 8% acrylate, 4% acrylate, 4% ammonium phosphate, 2% nano-alumina, 6% amine curing agent, 1.5% curing accelerator, 1.5% polyamide plasticizer, 0.8% polyvinyl alcohol stabilizer, 2.5% butyl acetate diluent, 0.2% surfactant, 0.1% defoaming agent, 1% zinc sulfide phosphor, and 1% cadmium sulfide phosphor.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0016] First, when the flame-retardant soft cable of the present invention is damaged, the automatic fusion characteristics of the self-repairing hierarchical structure are utilized to enable it to automatically repair the damaged part, and gradually solidify by reacting with the air. The fluorescent agent in the self-repairing hierarchical structure emits light at night, which is convenient for maintenance personnel to quickly identify the damaged part. The insulation layer prevents leakage, and the connecting layer maintains the stability between the layers. The automatic repair ability of the cable can avoid fire problems caused by electric shock, short circuit and other faults caused by cable damage. The insulation layer provides additional protection to ensure the safe operation of power equipment. The connecting layer maintains a stable connection between the layers. The design of the grid block separates the self-repairing hierarchical structure to avoid mutual influence, which is beneficial to the segmentation and cutting of the cable.

[0017] Second, when the outer protective layer of the flame-retardant soft cable of the present invention is damaged, the flame-retardant TPU can stretch and restore its shape to a certain extent; when the punctured object is separated from the damaged part, the flame-retardant TPU automatically closes the damaged part through its elasticity; at the same time, the adhesive filled in the interior of the connecting layer partition block flows out, fills the cracks at the closed part of the damaged part of the flame-retardant TPU, and reacts with oxygen in the air to achieve solidification, thereby achieving complete closure of the damaged part of the soft cable and improving the safety of the cable. Through the synergistic effect of the self-repairing hierarchical structure and the flame-retardant TPU, it can effectively prevent the cable from causing a fire due to leakage and ensure the safe use of the cable. The presence of the self-repairing hierarchical structure and the wear-resistant layer can extend the service life of the cable and reduce the replacement and repair costs caused by wear and damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0019] Figure 2 It is a schematic diagram of the connection layer structure of the present invention;

[0020] Figure 3 This is a structural diagram of embodiment 2 of the present invention.

[0021] Among them: 1. core; 2. wear-resistant layer; 3. self-repairing hierarchical structure; 4. insulation layer; 5. connection layer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] See also Figure 1 , Figure 2 , the present invention provides a technical solution:

[0025] A flame-retardant flexible cable comprises a core 1, a wear-resistant layer 2 is arranged on the outside of the core 1, a self-repairing hierarchical structure 3 is arranged between the wear-resistant layer 2 and the core 1, the self-repairing hierarchical structure 3 has the characteristics of automatic fusion or closure, and has the elasticity of colloid, can automatically fuse after being damaged, and gradually solidify by reacting with air, so that the fire-resistant cable has self-healing ability, when the cable is punctured, they can automatically repair through intermolecular interaction, and solidify after contact with air, fill the cracks on the outside of the cable, avoid the exposure of the internal conductive core 1, and prevent fire problems caused by faults such as electric shock and short circuit;

[0026] The self-repairing hierarchical structure 3 is mixed with fluorescent agent inside. The fluorescent agent is a powder that can emit visible light in the dark. When it is mixed with the self-repairing hierarchical structure 3, when the cable is damaged, the self-repairing hierarchical structure 3 will be exposed. The fluorescent agent in the self-repairing hierarchical structure 3 will glow at night, so that maintenance personnel can quickly identify the damaged area under dark conditions, and further implement maintenance or replacement measures on the flame-retardant soft cable to ensure the long-term and stable operation of the power facilities.

[0027] An insulating layer 4 is arranged between the self-repairing hierarchical structure 3 and the core 1, and the core 1 is further protected by the insulating layer 4. Even if the wear-resistant layer 2 and the self-repairing hierarchical structure 3 are damaged, the insulating layer 4 still protects the core 1 from leakage, avoids interference from the external environment, and ensures the operation of the power equipment.

[0028] A connection layer 5 is fixedly connected between the insulating layer 4 and the wear-resistant layer 2 . The connection layer 5 is formed by connecting a plurality of grid blocks. The insulating layer 4 and the wear-resistant layer 2 are kept stable by the connection layer 5 .

[0029] The self-repairing hierarchical structure 3 includes 58% polyether polyol, 39% toluene diisocyanate (TDI), 0.5% organic tin catalyst, appropriate amount of acetone, 1% zinc sulfide phosphor, and 1% cadmium sulfide phosphor;

[0030] In this formula, polyether polyol and TDI react to form polyurethane, which has a glue state and can be automatically fused; the catalyst is used to promote the reaction, and acetone is used as a solvent to adjust the viscosity and fluidity; the addition of zinc sulfide and cadmium sulfide phosphors enables the material to glow at night, and when the material is sealed in a certain space, if a leak occurs, contact with air will cause solidification.

[0031] The self-repairing hierarchical structure 3 is filled inside the compartment blocks of the connecting layer 5, and the compartment blocks seal and protect the self-repairing hierarchical structure 3. At the same time, several compartment blocks divide the self-repairing hierarchical structure 3 between the insulating layer 4 and the wear-resistant layer 2 into several parts. Each part acts independently relative to the damaged part to avoid mutual influence, thereby ensuring its stable function, which is beneficial to the segmentation and cutting of the flame-retardant flexible cable during use.

[0032] Embodiment 2:

[0033] See also Figure 2 , Figure 3 , and combined with Example 1, it is further obtained that the self-repairing hierarchical structure 3 includes flame-retardant TPU (thermoplastic polyurethane) and adhesive; the flame-retardant TPU layer is a double-layer structure, the connecting layer 5 is arranged between the two flame-retardant TPU layers, and the adhesive is filled in the grid blocks of the connecting layer 5. The flame-retardant TPU (thermoplastic polyurethane) has flame-retardant properties and good elasticity. When the outer protective layer of the soft cable is damaged, the flame-retardant TPU can be stretched and restored to a certain extent. When the punctured object is separated from the damaged part, the flame-retardant TPU automatically closes the damaged part through its elasticity. At the same time, the adhesive filled in the grid blocks of the connecting layer 5 flows out, fills the cracks at the closed part of the flame-retardant TPU damaged part, and reacts with oxygen in the air to achieve solidification, thereby achieving complete closure of the damaged part of the soft cable, preventing the leakage of the cable from causing a fire, and ensuring the safe use of the cable;

[0034] The flame retardant TPU layer comprises 40% of polyol, 40% of isocyanate, 10% of chain extender, 5% of flame retardant and 1% of antioxidant.

[0035] Here, the zinc sulfide phosphor 1% and cadmium sulfide phosphor 1% also have the function of luminescence at night, which is beneficial for the maintenance of the staff;

[0036] In this formula, polyols and isocyanates are the main components of TPU, which form polymer chains through reaction; chain extenders are used to increase the molecular weight and strength of polymers; the addition of flame retardants can improve the flame retardancy of materials; other ingredients, including lubricants, antioxidants, UV stabilizers, etc., can also be added to improve the performance and processing properties of materials. Flame retardants include halogen-containing flame retardants (such as bromine-based flame retardants) and halogen-free flame retardants (such as phosphorus-based flame retardants, nitrogen-based flame retardants, etc.).

[0037] The flame retardant is preferably triphenyl phosphate or melamine cyanurate.

[0038] Ingredients of the adhesive: 45% epoxy resin, 13% polyurethane, 8% acrylate, 4% acrylate, 4% ammonium phosphate, 2% nano-alumina, 6% amine curing agent, 1.5% curing accelerator, 1.5% polyamide plasticizer, 0.8% polyvinyl alcohol stabilizer, 2.5% butyl acetate diluent, 0.2% surfactant, 0.1% defoaming agent, 1% zinc sulfide phosphor, and 1% cadmium sulfide phosphor.

[0039] The adhesive has the characteristics of flame retardancy and rapid solidification after contact with air.

[0040] The following is a comparative experiment of curing with oxygen in combination with one-component polyurethane glue, acrylate UV-curing glue and the above-mentioned adhesive:

[0041] Purpose of the experiment: To compare the performance of one-component polyurethane adhesive, acrylic UV-curing adhesive and the adhesive in curing with oxygen.

[0042] Experimental materials: single-component polyurethane glue, acrylic UV-curing glue, adhesive of the present invention, oxygen supply device, curing time measuring instrument;

[0043] Experimental steps:

[0044] 1. Prepare three identical experimental groups, labeled A, B, and C respectively.

[0045] 2. In experimental group A, apply one-component polyurethane glue.

[0046] 3. In experimental group B, apply acrylate UV curing glue.

[0047] 4. In experimental group C, the adhesive of the present invention was applied.

[0048] 5. Expose the three experimental groups to oxygen environment at the same time.

[0049] 6. Use a curing time measuring instrument to record the curing time of each experimental group.

[0050] 7. Observe and record the curing conditions of each experimental group, including performance indicators such as hardness and strength after curing.

[0051] Data of control experiment results:

[0052]

[0053] Experimental analysis:

[0054] In terms of curing time, the curing speed of the adhesive of the present invention is the fastest, followed by the acrylic UV curing adhesive, and the curing speed of the single-component polyurethane adhesive is relatively slow.

[0055] From the perspective of hardness and strength after curing, the performance of the three adhesives is good, but the performance of the adhesive of the present invention is slightly better than the other two.

[0056] in conclusion:

[0057] The single-component polyurethane adhesive, the acrylic ester ultraviolet curing adhesive and the adhesive of the present invention all have good performance in curing in combination with oxygen.

[0058] The adhesive of the present invention has the fastest curing speed and its performance is slightly better than the other two.

[0059] Furthermore, the components of the wear-resistant layer 2 include: polyvinyl chloride (PVC): 60%; aluminum hydroxide: 20%; silicon dioxide: 3%.

[0060] Polyvinyl chloride (PVC) is a polymer matrix with good wear resistance and flame retardant properties. Aluminum hydroxide is a flame retardant. A proper amount of flame retardant is added to improve the flame retardant properties of the cable. Silicon dioxide is an anti-wear agent. Anti-wear agents are added to enhance the wear resistance of the outer layer of the cable. Plasticizers can be added to increase the flexibility and processing properties of the polymer; and stabilizers are added to improve the stability and durability of the outer layer of the cable.

[0061] Embodiment 3: The flame retardant TPU layer comprises 50% polyol, 30% isocyanate, 8% chain extender, 6% flame retardant and 1% antioxidant.

[0062] Here, the zinc sulfide phosphor 1% and cadmium sulfide phosphor 1% also have the function of luminescence at night, which is beneficial for the maintenance of the staff;

[0063] Example 4: Example 3: The flame retardant TPU layer comprises 60% polyol, 30% isocyanate, 5% chain extender, 5% flame retardant and 1% antioxidant.

[0064] Here, the zinc sulfide phosphor 1% and cadmium sulfide phosphor 1% also have the function of luminescence at night, which is beneficial for the maintenance of the staff;

[0065] Working principle of the present invention: When the cable is damaged, the automatic fusion characteristics of the self-repairing hierarchical structure 3 enable it to automatically repair the damaged part and gradually solidify by reacting with the air; the fluorescent agent in the self-repairing hierarchical structure 3 emits light at night, which is convenient for maintenance personnel to quickly identify the damaged part; the wear-resistant layer 2 provides external protection, the insulating layer 4 prevents leakage, and the connecting layer 5 maintains the stability between the layers. The above-mentioned flame-retardant soft cable has self-healing ability, which can avoid fire problems caused by electric shock, short circuit and other faults caused by cable damage, and its insulating layer 4 provides additional protection to ensure the safe operation of power equipment. And the design of the grid block separates the self-repairing hierarchical structure 3 to avoid mutual influence, which is conducive to the segmentation and cutting of the cable. Therefore, the B1-level soft cable has good flame retardant properties, self-healing ability and easy maintainability, which helps to improve the safety and reliability of power facilities.

[0066] Although specific embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the specific embodiments without departing from the principles and spirit thereof, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flame-retardant flexible cable, comprising a core (1), characterized in that: The core (1) is provided with a wear-resistant layer (2) on the outside, and a self-repairing hierarchical structure (3) is provided between the wear-resistant layer (2) and the core (1); The self-repairing hierarchical structure (3) comprises a flame-retardant TPU layer and an adhesive mixed with a fluorescent agent, wherein the ingredients of the adhesive are: 45% epoxy resin, 13% polyurethane, 8% acrylate, 4% acrylate, 4% ammonium phosphate, 2% nano-alumina, 6% amine curing agent, 1.5% curing accelerator, 1.5% polyamide plasticizer, 0.8% polyvinyl alcohol stabilizer, 2.5% butyl acetate diluent, 0.2% surfactant, 0.1% defoaming agent, 1% zinc sulfide fluorescent powder, and 1% cadmium sulfide fluorescent powder.

2. A flame-retardant flexible cable according to claim 1, characterized in that: An insulating layer (4) is provided between the self-repairing hierarchical structure (3) and the core (1).

3. A flame-retardant flexible cable according to claim 2, characterized in that: A connecting layer (5) is fixedly connected between the insulating layer (4) and the wear-resistant layer (2), and the connecting layer (5) is formed by connecting a plurality of grid blocks.

4. A flame-retardant flexible cable according to claim 3, characterized in that: The self-repairing hierarchical structure (3) comprises 58% of polyether polyol, 39% of toluene diisocyanate, 0.5% of an organic tin catalyst, an appropriate amount of acetone, 1% of zinc sulfide phosphor, and 1% of cadmium sulfide phosphor; the self-repairing hierarchical structure (3) is filled inside the grid blocks of the connection layer (5).

5. The flame-retardant flexible cable according to claim 3, characterized in that: The flame retardant TPU layer is a double-layer structure, the connecting layer (5) is arranged between the two flame retardant TPU layers, and the adhesive is filled inside the cell blocks of the connecting layer (5); The flame retardant TPU layer comprises 40%-60% of polyol, 30%-50% of isocyanate, 5%-15% of chain extender, 5%-20% of flame retardant and 1% of antioxidant.

6. A flame-retardant flexible cable according to claim 5, characterized in that: The flame retardant is one or more of triphenyl phosphate and melamine cyanurate.

7. The flame-retardant flexible cable according to claim 1, characterized in that: The components of the wear-resistant layer (2) include: polyvinyl chloride (PVC): 60%-70%; aluminum hydroxide: 10%-20%; and silicon dioxide 3%.

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