Frost-crack-resistant cable and preparation method thereof

Abstract

The invention discloses an anti-frost-crack cable and a preparation method thereof, and relates to the field of cable materials. The frost-crack-resistant cable comprises an outer sheath, a shielding layer, a wrapping layer and a cable core which are sequentially arranged from outside to inside, wherein a filling layer is arranged in a gap between the cable core and the wrapping layer; the outer sheath is prepared from the following raw materials in parts by weight: 100 parts of methyl vinyl silicone rubber, 20-30 parts of a modified filler, 1-1.5 parts of a peroxide crosslinking agent, 1.5-2.5 parts of a coloring agent, 25-35 parts of a flame retardant and 2-4 parts of hydroxyl silicone oil; in the methyl vinyl silicone rubber, the content of vinyl is 0.1 to 0.2 percent; the modified filler is obtained by grafting an alkenyl silane coupling agent to a filler to obtain a silane coupling agent modified filler, and then carrying out hydrosilylation reaction on the silane coupling agent modified filler and hydrogen-containing fluorosilicone oil. The anti-frost-crack cable has excellent anti-frost-crack performance and mechanical performance, and can be applied in a severe cold environment.

Description

Technical Field

[0001] This application relates to the field of cable materials, and particularly to an anti-freezing and cracking cable and its preparation method. Background Art

[0002] As an important part of modern power and communication systems, cables are widely used in industries, buildings, transportation and other fields, and their performance directly affects the stability of power transmission and the quality of communication signals. With the development of technology, the usage environment of cables has become increasingly diverse, especially the application requirements in low-temperature environments are constantly increasing. However, the outer sheaths of traditional cables are prone to cracking problems in low-temperature environments, seriously affecting the popularization and application of cables in severe cold environments, especially in low-temperature environments above -70°C. Summary of the Invention

[0003] In order to improve the problem that traditional cables are difficult to be popularized and applied in environments above -70°C, this application provides an anti-freezing and cracking cable and its preparation method.

[0004] In the first aspect, an anti-freezing and cracking cable provided by this application adopts the following technical solution: An anti-freezing and cracking cable includes an outer sheath, a shielding layer, a wrapping layer and a cable core arranged in sequence from outside to inside, and a filling layer is provided in the gap between the cable core and the wrapping layer; the preparation raw materials of the outer sheath include 100 parts by weight of methyl vinyl silicone rubber, 20 - 30 parts by weight of modified filler, 1 - 1.5 parts by weight of peroxide cross-linking agent, 1.5 - 2.5 parts by weight of coloring agent, 25 - 35 parts by weight of flame retardant and 2 - 4 parts by weight of hydroxy silicone oil; in the methyl vinyl silicone rubber, the content of vinyl is 0.1 - 0.2%; the modified filler is obtained by grafting an alkenyl silane coupling agent to the filler to obtain a silane coupling agent-modified filler, and then carrying out a hydrosilylation reaction between the silane coupling agent-modified filler and hydrogen fluoride-containing silicone oil.

[0005] In this application, the content of vinyl in the methyl vinyl silicone rubber is controlled at 0.1 - 0.2%, and through the cooperation of a peroxide cross-linking agent and a modified filler in a specific ratio, the cable can be applicable to a low-temperature environment of -70°C and is not prone to brittle cracking, especially suitable for severe cold regions. Among them, the modified filler is obtained by modifying the filler with an alkenyl silane coupling agent and hydrogen fluoride-containing silicone oil, significantly improving the dispersion of the filler in the silicone rubber matrix, and the interfacial bonding strength between the modified filler and the silicone rubber is high, which can improve the mechanical tensile strength and anti-freezing and cracking performance of the cable outer sheath. In addition, the addition of the flame retardant is used to improve the flame retardant performance of the cable outer sheath, and the hydroxy silicone oil is used to assist the uniform dispersion of the flame retardant.

[0006] In some specific embodiments, the mass ratio of the alkenyl silane coupling agent to the filler is (0.3 - 0.5):10, and the mass ratio of the silane coupling agent-modified filler to the hydrogen-containing fluorosilicone oil is 10:(4 - 6).

[0007] In this application, by controlling the weight ratio of each raw material in the modified filler within the above range, the dispersion of the filler in the silicone rubber matrix is effectively improved, the interfacial bonding strength between the filler and the silicone rubber matrix is increased, and the mechanical properties and anti-freezing crack properties of the outer sheath can be enhanced.

[0008] In some specific embodiments, the structural formula of the hydrogen-containing fluorosilicone oil is as follows: Among them, the value range of m is 1 - 2, the value range of n is 8 - 15, and the value range of x is 1 - 2.

[0009] In this application, when using the hydrogen-containing fluorosilicone oil with the above structure to modify the filler, the residual silicon-hydrogen bond in the modified filler can perform a hydrosilylation reaction with the vinyl group in the vinyl methyl silicone rubber, which is beneficial to further enhancing the interfacial bonding strength between the modified filler and the silicone rubber matrix. At the same time, by controlling an appropriate fluorine content, the hydrophobic property of the outer sheath can be improved, and the probability of ice formation on the outer sheath can be reduced, thereby further improving the anti-freezing crack property of the cable outer sheath without affecting the dispersion performance of the modified filler.

[0010] Preferably, the values of m and x are 2, and the value of n is 10 - 12.

[0011] In this application, when the values of m and x in the hydrogen-containing fluorosilicone oil are 2 and the value of n is 10 - 12, the hydrogen-containing fluorosilicone oil with this specific structure can more effectively improve the dispersion of the modified filler in the silicone rubber matrix and enhance the interfacial bonding strength between the modified filler and the silicone rubber matrix, enabling the cable outer sheath to be applicable to a low-temperature environment of -100°C. At the same time, the mechanical tensile strength of the outer sheath is also maximally improved.

[0012] In some specific embodiments, the filler is a composition with a mass ratio of fumed silica to nano calcium carbonate of 1:(3 - 4).

[0013] In this application, when fumed silica and nano calcium carbonate are used in combination according to a specific mass ratio, the mechanical tensile strength and anti-freezing crack property of the outer sheath can be ensured while reducing the cost.

[0014] In some specific embodiments, the alkenyl silane coupling agent is vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2 - methoxyethoxy)silane, vinyltris(diethylphosphoryloxy)silane, or γ - methacryloxypropyltrimethoxysilane.

[0015] In some specific embodiments, the peroxide crosslinking agent is bis(2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane), bis(4-methylbenzoyl)peroxide, dicumyl peroxide or bis(tert-butylperoxyisopropyl)benzene.

[0016] Preferably, the peroxide crosslinking agent is a composition of bis(2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane) and bis(4-methylbenzoyl)peroxide with a weight ratio of (1 - 1.5):1.

[0017] In this application, the peroxide crosslinking agent is preferably a composition in which bis(2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane) and bis(4-methylbenzoyl)peroxide are compounded in a specific ratio, which can significantly improve the crosslinking density and uniformity of the outer sheath material. It can not only enhance the mechanical properties of the outer sheath, but also further improve the anti-freezing and cracking performance of the cable outer sheath in a low-temperature environment.

[0018] In some specific embodiments, the flame retardant is aluminum hydroxide modified with an alkenyl silane coupling agent.

[0019] In a second aspect, a preparation method of an anti-freezing and cracking cable provided by this application adopts the following technical solution: A preparation method of an anti-freezing and cracking cable includes the following steps: Fill a filling layer on the outer surface of the cable core, then wrap a wrapping layer on the outer surface of the filling layer, and then braid a shielding layer on the outer surface of the wrapping layer to obtain a cable without a sheath; Mix methyl vinyl silicone rubber, modified filler, flame retardant, colorant, and hydroxy silicone oil evenly at 80 - 100 °C, then cool down to below 50 °C, add the peroxide crosslinking agent and continue mixing to obtain silicone rubber material; extrude the silicone rubber material onto the outer surface of the cable without a sheath at 120 - 150 °C, and then transfer the cable into an environment of 200 - 250 °C for vulcanization to obtain an anti-freezing and cracking cable.

[0020] In summary, this application includes at least the following beneficial technical effects: (1) Through the cooperation of methyl vinyl silicone rubber, modified filler, peroxide crosslinking agent, colorant, flame retardant, and hydroxy silicone oil with specific ratios, this application can effectively improve the anti-freezing and cracking performance of the cable outer sheath, enabling the cable outer sheath to meet the popularization and application in a -70 °C low-temperature environment. At the same time, the addition of the modified filler obtained by the hydrosilylation reaction of the silane coupling agent-modified filler and hydrogen-containing fluorosilicone oil can simultaneously improve the mechanical tensile strength of the cable outer sheath.

[0021] (2) In this application, when the values of m and x in the hydrogen-containing fluorosilicone oil are 2 and the value of n is 10 - 12, the hydrogen-containing fluorosilicone oil with this specific structure can more effectively improve the dispersion of the modified filler in the silicone rubber matrix and enhance the interfacial bonding strength between the modified filler and the silicone rubber matrix, enabling the cable outer sheath to be applicable to a low-temperature environment of -100°C. At the same time, the mechanical tensile strength of the outer sheath is also maximally improved. Brief Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the anti-freezing and cracking cable of this application.

[0023] Description of the Reference Numerals: 1. Outer sheath; 2. Shielding layer; 3. Wrapping layer; 4. Cable core; 41. Conductor; 42. Insulating layer; 5. Filling layer. Detailed Embodiments

[0024] The following further describes this application in combination with specific experiments.

[0025] Preparation Examples

Preparation Example 1

[0026] Among them, the filler in Sa includes fumed silica and nano calcium carbonate, and the weight ratio of fumed silica to nano calcium carbonate is 1:3; the structural formula of the hydrogen-containing fluorosilicone oil is as follows: The value range of m is 1, the value range of n is 8, and the value range of x is 1.

[0027]

Preparation Example 2

[0028] Among them, the filler in Sa includes fumed silica and nano-calcium carbonate, and the weight ratio of fumed silica to nano-calcium carbonate is 1:4. The structural formula of the hydrogen-containing fluorosilicone oil is as follows: The value range of m is 1, the value range of n is 15, and the value range of x is 1.

[0029]

Preparation Example 3

Preparation Example 1

[0030]

Preparation Example 4

Preparation Example 1

[0031]

Preparation Example 5

Preparation Example 3

[0032]

Preparation Example 6

Preparation Example 4

[0033] Comparative Preparation Example

Comparative Preparation Example 1

Example 1

[0034]

Example 1

Preparation Example 1

[0035] The preparation method of the anti-freezing and cracking cable includes the following steps: Fill the filling layer on the outer surface of the cable core, then wrap the wrapping layer on the outer surface of the filling layer, and then braid the shielding layer on the outer surface of the wrapping layer to obtain a cable without a sheath; Mix the methyl vinyl silicone rubber, the modified filler, the flame retardant, the coloring agent, and the hydroxy silicone oil evenly at 80°C, then cool down to below 50°C, add the peroxide cross-linking agent and continue to mix to obtain a silicone rubber material; Extrude the silicone rubber material onto the outer surface of the cable without a sheath at 120°C, and then transfer the cable into an environment of 250°C and vulcanize for 30 s to obtain an anti-freezing and cracking cable.

[0036]

Example 2

Example 1

[0037] In this embodiment, the raw materials for preparing the outer sheath include 100 kg of methyl vinyl silicone rubber, 30 kg of the modified filler prepared in

Preparation Example 2

[0038] The preparation method of the freezing and cracking cable includes the following steps: A filler layer is filled on the outer surface of the cable core, then a wrapping layer is wrapped on the outer surface of the filler layer, and then a shielding layer is braided on the outer surface of the wrapping layer to obtain a cable without a sheath; Mix methyl vinyl silicone rubber, modified filler, flame retardant, colorant, and hydroxyl silicone oil evenly at 100 °C, then cool down to below 50 °C, add a peroxide crosslinking agent and continue mixing to obtain a silicone rubber compound; extrude the silicone rubber compound onto the outer surface of the cable without a sheath at 150 °C, and then transfer the cable into an environment of 200 °C for vulcanization for 1 min to obtain an anti-freezing and cracking cable.

[0039]

Example 3

Example 1

Preparation Example 3

[0040]

Example 4

Example 1

Preparation Example 4

[0041]

Example 5

Example 1

Preparation Example 5

[0042]

Example 6

Example 1

Preparation Example 6

[0043] Comparative example

Comparative Example 1

Example 1

Comparative Preparation Example 1

[0044] Performance detection test 1. Low-temperature anti-freezing and cracking performance: Treat the cables in each example and comparative example in environments of -70 °C, -85 °C, and -100 °C for 24 h, with an environmental humidity of 85%. After the freezing treatment is completed, take out the cables and place them in the natural environment. After the temperature of the cables naturally returns to 20 - 25 °C, take 10 cable specimens from each example and comparative example that have completed the freezing treatment respectively, bend the specimens by 90 °C, and observe whether there are cracking problems in the outer sheaths of the cables. Among them, if more than 90% of the cable specimens do not crack, it is considered qualified.

[0045] 2. Tensile strength: Detect the tensile strength of the outer sheath with reference to the regulations in GB / T 33430-2016, and the test speed is 500 mm / min.

[0046] Table 1 Low-temperature anti-freezing crack test Table 2 Tensile strength test specimen Tensile strength MPa Example 1 9.2 Example 2 8.9 Example 3 9.6 Example 4 9.1 Example 5 10.2 Example 6 9.7 Comparative Example 1 7.3 Combined with the detection data in Example 1 and Comparative Example 1 of this application and Tables 1-2, it can be seen that when preparing the modified filler, using dihydrogen-terminated polydimethylsiloxane to replace the specific hydrogen-containing fluorosilicone oil of this application, the anti-freezing crack performance and tensile strength of the cable outer sheath both decrease significantly.

[0047] Combined with the detection data in Example 1 and Examples 3-4 of this application and Tables 1-2, it can be seen that the length of the fluorine-containing chain segment in the hydrogen-containing fluorosilicone oil affects the anti-freezing crack performance and tensile strength performance of the cable outer sheath. Among them, as the polymerization degree of the fluorine-containing chain segment increases, the anti-freezing performance of the cable outer sheath generally improves. However, when the polymerization degree of the fluorine-containing chain segment is too large, it is easy to cause the limited improvement of the tensile strength of the cable outer sheath. The reason may be that the excessive polymerization degree of the fluorine-containing chain segment slightly decreases the dispersibility of the modified filler.

[0048] Combined with the detection data in Example 3 and Example 5 of this application, Example 4 and Example 6, and Tables 1-2, it can be seen that an appropriate increase in the content of silicon-hydrogen bonds is beneficial to further improving the tensile strength of the cable outer sheath.

[0049] This specific embodiment is only an interpretation of this application, and it is not a limitation of this application. After reading this specification, those skilled in the art can make modifications without creative contributions to this specific embodiment as needed, but as long as they are within the scope of the claims of this application, they are protected by the patent law.

Claims

1. An anti-freezing and cracking cable, characterized in that: It includes an outer sheath, a shielding layer, a wrapping layer and a cable core which are arranged from outside to inside in sequence. A filling layer is provided in the gap between the cable core and the wrapping layer; The preparation raw materials of the outer sheath include 100 parts by weight of methyl vinyl silicone rubber, 20 - 30 parts by weight of modified filler, 1 - 1.5 parts by weight of peroxide crosslinking agent, 1.5 - 2.5 parts by weight of colorant, 25 - 35 parts by weight of flame retardant and 2 - 4 parts by weight of hydroxyl silicone oil; In the methyl vinyl silicone rubber, the content of vinyl is 0.1 - 0.2%; The modified filler is obtained by grafting a filler with an alkenyl silane coupling agent to obtain a silane coupling agent - modified filler, and then carrying out a hydrosilylation reaction between the silane coupling agent - modified filler and a hydrogen - containing fluorosilicone oil.

2. The anti-freezing and cracking cable according to claim 1, wherein: The mass ratio of the alkenyl silane coupling agent to the filler is (0.3 - 0.5):10, and the mass ratio of the silane coupling agent - modified filler to the hydrogen - containing fluorosilicone oil is 10:(4 - 6).

3. An anti-freezing and cracking cable according to claim 1, characterized in that: The structural formula of the hydrogen - containing fluorosilicone oil is as follows: Among them, the value range of m is 1 - 2, the value range of n is 8 - 15, and the value range of x is 1 - 2.

4. The anti-freezing and cracking cable according to claim 3, characterized in that: The values of m and x are 2, and the value of n is 10 - 12.

5. The anti-freezing and cracking cable according to claim 2, wherein: The filler adopts a composition with a mass ratio of fumed silica and nano - calcium carbonate of 1:(3 - 4).

6. The anti-freezing and cracking cable according to claim 2, wherein: The alkenyl silane coupling agent adopts at least one of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2 - methoxyethoxy)silane, vinyltris(diethylphosphoryloxy)silane, γ - methacryloxypropyltrimethoxysilane.

7. The anti-freezing and cracking cable according to claim 1, characterized in that: The peroxide crosslinking agent adopts at least one of bis - 2,5 (2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)hexane), bis(4 - methylbenzoyl)peroxide, dicumyl peroxide, bis - tert - butylperoxyisopropylbenzene.

8. The anti-freezing and cracking cable according to claim 7, characterized in that: The peroxide crosslinking agent adopts a composition with a weight ratio of bis - 2,5 (2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)hexane) and bis(4 - methylbenzoyl)peroxide of (1 - 1.5):

1.

9. The anti-cracking cable according to claim 1, characterized in that: The flame retardant adopts an alkenyl silane coupling agent - modified aluminum hydroxide.

10. A method for preparing an anti-freezing and cracking cable according to any one of claims 1-9, characterized in that, It includes the following steps: Fill the filling layer on the outer surface of the cable core, then wrap the wrapping layer on the outer surface of the filling layer, and then braid the shielding layer on the outer surface of the wrapping layer to obtain a cable without a sheath; Mix methyl vinyl silicone rubber, modified filler, flame retardant, colorant, and hydroxyl silicone oil evenly at 80 - 100 °C, then cool down to below 50 °C, add the peroxide crosslinking agent and continue mixing to obtain a silicone rubber material; extrude the silicone rubber material onto the outer surface of the cable without a sheath at 120 - 150 °C, and then transfer the cable into an environment of 200 - 250 °C for vulcanization to obtain an anti - freeze - cracking cable.

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