An anti-cracking cable and a method for manufacturing the same

Abstract

The application discloses an anti-freezing and cracking cable and a preparation method thereof, and relates to the field of cable materials. The anti-freezing and cracking cable comprises, from outside to inside, an outer sheath, a shielding layer, a wrapping layer and a cable core, and a filling layer is arranged in the gap between the cable core and the wrapping layer; the preparation raw material of the outer sheath comprises 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 colorant, 25-35 parts by weight of flame retardant and 2-4 parts by weight of hydroxyl silicone oil; the content of vinyl in the methyl vinyl silicone rubber is 0.1-0.2%; the modified filler is obtained by grafting filler with alkenyl silane coupling agent to obtain silane coupling agent modified filler, and then by carrying out silane hydrogen addition reaction between the silane coupling agent modified filler and hydrogen-containing fluorosilicone oil. The anti-freezing and cracking cable has excellent anti-freezing and cracking performance and mechanical performance, and can be applied in a severe cold environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cable materials, in particular to an anti-cracking cable and a preparation method thereof. BACKGROUND

[0002] As an important component in 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 use environment of cables is becoming increasingly diversified, and the demand for their application in low-temperature environments is increasing. However, the outer sheath of traditional cables is prone to cracking in low-temperature environments, which seriously affects the popularization and application of cables in cold environments, especially in low-temperature environments above -70℃. SUMMARY

[0003] In order to improve the problem that traditional cables are difficult to popularize and apply in environments above -70℃, the present application provides an anti-cracking cable and a preparation method thereof.

[0004] In a first aspect, the present application provides an anti-cracking cable using the following technical solution:

[0005] An anti-cracking cable, comprising an outer sheath, a shielding layer, a wrapping layer and a cable core arranged in sequence from the outside to the inside, and a filling layer arranged 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; the content of vinyl in the methyl vinyl silicone rubber 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 by performing a silicon-hydrogen addition reaction on the silane coupling agent modified filler and hydrogen-containing fluorosilicone oil.

[0006] In the present application, the content of vinyl in the methyl vinyl silicone rubber is controlled to be 0.1-0.2%, and the peroxide crosslinking agent and the modified filler are matched in a specific ratio, so that the cable can be applied in a low-temperature environment of -70℃ and is not prone to brittle cracking, especially in cold regions. The modified filler is obtained by modifying the filler with an alkenyl silane coupling agent and hydrogen-containing fluorosilicone oil, which significantly improves the dispersibility of the filler in the silicone rubber matrix, and the interface bonding strength between the modified filler and the silicone rubber is high, which can improve the mechanical tensile strength and anti-cracking performance of the outer sheath of the cable. In addition, the addition of the flame retardant improves the flame retardant performance of the outer sheath of the cable, and the hydroxyl silicone oil is used to assist the uniform dispersion of the flame retardant.

[0007] 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).

[0008] In the present application, the weight ratio of each raw material in the modified filler is controlled within the above range, which effectively improves the dispersibility of the filler in the silicone rubber matrix, increases the interfacial bonding strength between the filler and the silicone rubber matrix, and can enhance the mechanical properties and anti-cracking properties of the outer sheath.

[0009] In some specific embodiments, the hydrogen-containing fluorosilicone oil has the following structural formula:

[0010]

[0011] wherein m is in the range of 1-2, n is in the range of 8-15, and x is in the range of 1-2.

[0012] In the present application, when the hydrogen-containing fluorosilicone oil with the above structure is used to modify the filler, the residual silicon-hydrogen bond in the modified filler can undergo silicon-hydrogen addition with the vinyl group in the vinyl methyl silicone rubber, which is conducive to further improving the interfacial bonding strength between the modified filler and the silicone rubber matrix. At the same time, by controlling the appropriate fluorine content, the hydrophobic properties of the outer sheath can be improved, and the probability of icing on the outer sheath can be reduced, thereby further improving the anti-cracking properties of the cable outer sheath without affecting the dispersibility of the modified filler.

[0013] Preferably, m and x are 2, and n is in the range of 10-12.

[0014] In the present application, when m and x are 2, and n is in the range of 10-12 in the hydrogen-containing fluorosilicone oil, the hydrogen-containing fluorosilicone oil with this specific structure can more effectively improve the dispersibility of the modified filler in the silicone rubber matrix and increase the interfacial bonding strength between the modified filler and the silicone rubber matrix, so that the cable outer sheath can be applied to a low temperature environment of-100℃. At the same time, the mechanical tensile strength of the outer sheath is also maximized.

[0015] In some specific embodiments, the filler is a combination of fumed silica and nano calcium carbonate in a mass ratio of 1:(3-4).

[0016] In the present application, fumed silica and nano calcium carbonate are used in a specific mass ratio, which can reduce costs while ensuring the mechanical tensile strength and anti-cracking properties of the outer sheath.

[0017] In some specific embodiments, the alkenyl silane coupling agent is vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(2-methoxyethoxy)silane, vinyl tri(diethylphosphatoxy)silane or gamma-methacryloxypropyltrimethoxysilane.

[0018] 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-butylperoxyisopropylbenzene.

[0019] Preferably, the peroxide crosslinking agent is a combination of bis(2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane) and bis(4-methylbenzoyl)peroxide in a weight ratio of (1-1.5):1.

[0020] In the present application, the peroxide crosslinking agent is preferably a combination of bis(2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane) and bis(4-methylbenzoyl)peroxide in a specific ratio, which can significantly improve the crosslinking density and uniformity of the outer sheath material, not only enhancing the mechanical properties of the outer sheath, but also further improving the anti-cracking performance of the cable outer sheath in low temperature environment.

[0021] In some specific embodiments, the flame retardant is modified aluminum hydroxide with alkenyl silane coupling agent.

[0022] In a second aspect, the present application provides a preparation method of an anti-cracking cable, which adopts the following technical scheme:

[0023] A preparation method of an anti-cracking cable, comprising the following steps:

[0024] Filling a filler layer on the outer surface of the cable core, then wrapping a wrapping layer on the outer surface of the filler layer, and then weaving a shielding layer on the outer surface of the wrapping layer to obtain a sheathless cable;

[0025] Mixing methyl vinyl silicone rubber, modified filler, flame retardant, colorant and hydroxyl silicone oil uniformly at 80-100℃, then cooling to below 50℃, adding peroxide crosslinking agent and continuing to mix to obtain a silicone rubber material; extruding the silicone rubber material to the outer surface of the sheathless cable at 120-150℃, then transferring the cable into an environment of 200-250℃ for vulcanization to obtain an anti-cracking cable.

[0026] In summary, the present application at least includes the following beneficial technical effects:

[0027] (1) The application can effectively improve the anti-cracking performance of the cable outer sheath by matching methyl vinyl silicone rubber, modified filler, peroxide crosslinking agent, colorant, flame retardant and hydroxyl silicone oil in a specific ratio, so that the cable outer sheath can meet the popularization and application in a low temperature environment of-70℃. At the same time, the mechanical tensile strength of the cable outer sheath can be improved simultaneously by adding the modified filler obtained by the silicon-hydrogen addition reaction of the silane coupling agent modified filler and the hydrogen-containing fluorosilicone oil.

[0028] (2) In the 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 dispersibility of the modified filler in the silicone rubber matrix and improve the interfacial bonding strength of the modified filler and the silicone rubber matrix, so that the cable outer sheath can be applied to a low temperature environment of-100℃, and at the same time, the mechanical tensile strength of the outer sheath is also maximally improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic diagram of the anti-cracking cable of the application.

[0030] BRIEF DESCRIPTION OF DRAWINGS

[0031] 1, outer sheath; 2, shielding layer; 3, wrapping layer; 4, cable core; 41, conductor; 42, insulation layer; 5, filling layer. DETAILED DESCRIPTION

[0032] The application will be further described below in combination with specific experiments.

[0033] Preparation Example

[0034] Preparation Example 1

[0035] A modified filler, the preparation method is as follows:

[0036] Sa, 0.3kg of vinyltrimethoxysilane is dissolved in 100kg of ethanol solution with a mass concentration of 75%, then 10kg of filler is added, stirred at 50℃ for 60min, then filtered, the filter residue is washed and dried to obtain a silane coupling agent modified filler;

[0037] Sb, 4kg of hydrogen-containing fluorosilicone oil is added to perfluorohexane, then 10kg of silane coupling agent modified filler and 0.002kg of Speier catalyst are added, heated to 80℃, and reacted for 2h, then filtered, the filter residue is washed and dried to obtain a modified filler.

[0038] In Sa, the filler includes fumed silica and nano calcium carbonate, and the weight ratio of fumed silica and nano calcium carbonate is 1:3; the structure of the hydrogen-containing fluorosilicone oil is as follows:

[0039]

[0040] m is 1, n is 8, and x is 1.

[0041] Preparation Example 2

[0042] A modified filler is prepared by the following method:

[0043] Sa, 0.5 kg of vinyltriethoxysilane is dissolved in 100 kg of an ethanol solution with a mass concentration of 75%, then 10 kg of a filler is added, and stirring is performed at 60°C for 40 min, then filtration is performed, the filter residue is washed and dried to obtain a silane coupling agent modified filler;

[0044] Sb, 6 kg of hydrogen-containing fluorosilicone oil is added to perfluorohexane, then 10 kg of a silane coupling agent modified filler and 0.002 kg of Speier catalyst are added, and the temperature is increased to 120°C, and reaction is performed for 1 h, then filtration is performed, the filter residue is washed and dried to obtain a modified filler.

[0045] In the formula, the filler in Sa includes fumed silica and nano calcium carbonate, and the weight ratio of the fumed silica and the nano calcium carbonate is 1:4; the hydrogen-containing fluorosilicone oil has the following structure:

[0046]

[0047] m is 1, n is 15, and x is 1.

[0048] Preparation Example 3

[0049] A modified filler, which is different from the modified filler in Preparation Example 1, is that the value of n in the hydrogen-containing fluorosilicone oil is different, and in this preparation example, the value of n in the hydrogen-containing fluorosilicone oil ranges from 12.

[0050] Preparation Example 4

[0051] A modified filler, which is different from the modified filler in Preparation Example 1, is that the value of n in the hydrogen-containing fluorosilicone oil is different, and in this preparation example, the value of n in the hydrogen-containing fluorosilicone oil ranges from 15.

[0052] Preparation Example 5

[0053] A modified filler, which is different from the modified filler in Preparation Example 3, is that the values of m and x in the hydrogen-containing fluorosilicone oil are different, and in this preparation example, the value of m in the hydrogen-containing fluorosilicone oil ranges from 2, and the value of x ranges from 2.

[0054] Preparation Example 6

[0055] A modified filler, which is different from

Preparation Example 4

[0056] Comparative Preparation Example

[0057]

Comparative Preparation Example 1

[0058] A modified filler, which is different from

Preparation Example 4

[0059] The hydrogen-containing fluorosilicone oil is replaced by an equal amount of double hydrogen-terminated polydimethylsiloxane with a molecular weight of 1000.

[0060] Preparation Example

[0061]

Preparation Example 1

[0062] An anti-cracking cable, referring to Figure 1 , comprising an outer sheath, a shielding layer, a wrapping layer and a cable core arranged in turn from the outside, the cable core comprises a conductor and an insulating layer wrapped on the outer peripheral side of the conductor, and a filler layer is arranged in the gap between the cable core and the wrapping layer. Among them, the raw materials for preparing the outer sheath include 100 kg of methyl vinyl silicone rubber, 20 kg of modified filler prepared by

Preparation Example 1

[0063] The preparation method of the anti-cracking cable comprises the following steps:

[0064] The filler layer is filled on the outer surface of the cable core, then the wrapping layer is wrapped on the outer surface of the filler layer, and then the shielding layer is woven on the outer surface of the wrapping layer to obtain a sheathless cable;

[0065] The methyl vinyl silicone rubber, the modified filler, the flame retardant, the colorant and the hydroxyl silicone oil are uniformly mixed at 80°C, then the temperature is lowered to below 50°C, the peroxide crosslinking agent is added and continuously mixed to obtain a silicone rubber material; the silicone rubber material is extruded onto the outer surface of the sheathless cable at 120°C, then the cable is transferred into an environment of 250°C for vulcanization for 30s to obtain an anti-cracking cable.

[0066]

Preparation Example 2

[0067] An anti-freeze cable, which is different from

Example 1

[0068] In this embodiment, the preparation raw material of the outer sheath includes 100 kg of methyl vinyl silicone rubber, 30 kg of modified filler prepared in

Preparation Example 2

[0069] The preparation method of the freeze cable includes the following steps:

[0070] The filling layer is filled on the outer surface of the cable core, then the wrapping layer is coated on the outer surface of the filling layer, and then the shielding layer is woven on the outer surface of the wrapping layer to obtain a sheathless cable;

[0071] The methyl vinyl silicone rubber, modified filler, flame retardant, colorant, and hydroxyl silicone oil are uniformly mixed at 100℃, then the temperature is lowered to below 50℃, the peroxide crosslinking agent is added and continuously mixed to obtain a silicone rubber material; the silicone rubber material is extruded onto the outer surface of the sheathless cable at 150℃, then the cable is transferred into an environment of 200℃ for vulcanization for 1 min to obtain an anti-freeze cable.

[0072]

Example 3

[0073] An anti-freeze cable, which is different from

Example 1

Preparation Example 3

[0074]

Example 4

[0075] An anti-freeze cable, which is different from

Example 1

Preparation Example 4

[0076]

Example 5

[0077] An anti-freeze cable, which is different from

Example 1

Preparation Example 5

[0078]

Example 6

[0079] An anti-cracking cable, which differs from

Example 1

Preparation Example 6

[0080] Comparative Example

[0081]

Comparative Example 1

[0082] An anti-cracking cable, which differs from

Example 1

Comparative Preparation Example 1

[0083] Performance test

[0084] 1. Low-temperature anti-cracking performance: the cables in each example and comparative example were respectively treated at -70℃, -85℃ and -100℃ for 24h, and the ambient humidity was 85%. After the cold treatment was completed, the cables were taken out and placed in a natural environment. After the temperature of the cables naturally recovered to 20-25℃, 10 cable samples of each example and comparative example that completed the cold treatment were taken, and the samples were bent 90°. The outer sheath of the cable was observed for cracking problems. More than 90% of the cable samples that did not crack were considered to be qualified.

[0085] 2. Tensile strength: the tensile strength of the outer sheath was detected according to the provisions in GB / T 33430-2016, and the test speed was 500mm / min.

[0086] Table 1 Low-temperature anti-cracking test

[0087]

[0088] Table 2 Tensile strength test

[0089] 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

[0090] According to the detection data in Example 1 and Comparative Example 1 of the present application and Tables 1-2, when preparing the modified filler, using a double hydrogen-terminated polydimethylsiloxane instead of the specific hydrogen-containing fluorosilicone oil of the present application, the anti-cracking performance and tensile strength of the cable outer sheath are both greatly reduced.

[0091] According to the detection data in Example 1 and Examples 3-4 of the present application and Tables 1-2, the length of the fluorine-containing segment in the hydrogen-containing fluorosilicone oil affects the anti-cracking performance and tensile strength performance of the cable outer sheath. As the polymerization degree of the fluorine-containing segment increases, the anti-cracking performance of the cable outer sheath generally improves, but when the polymerization degree of the fluorine-containing segment is too large, the tensile strength of the cable outer sheath is limited to improve, which may be caused by the slight decrease in the dispersibility of the modified filler due to the too large polymerization degree of the fluorine-containing segment.

[0092] From the test data in Table 1-2 of Example 3 and Example 5 and Example 4 and Example 6, it can be seen that the appropriate increase of the content of silicon-hydrogen bond is beneficial to further improve the tensile strength of the outer sheath of the cable.

[0093] The specific embodiment is only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the specific embodiment without creative contribution after reading the specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A freeze-resistant cable, characterized in that: The cable comprises, from the outside in, an outer sheath, a shielding layer, a wrapping layer, and a cable core, wherein a filling layer is provided between the cable core and the wrapping layer; the raw materials for preparing 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; the vinyl content in the methyl vinyl silicone rubber is 0.1-0.2%; the modified filler is obtained by grafting an alkenyl silane coupling agent onto a filler to obtain a silane coupling agent modified filler, and then by a hydrosilylation reaction between the silane coupling agent modified filler and hydrofluoric silicone oil; 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 hydrofluoric silicone oil is 10:(4-6). The filler is a composition of fumed silica and nano-calcium carbonate in a mass ratio of 1:(3-4); The structural formula of the hydrofluoric silicone oil is as follows: ； Where m ranges from 1 to 2, n ranges from 8 to 15, and x ranges from 1 to 2.

2. The anti-freeze crack cable according to claim 1, characterized in that: The values ​​of m and x are 2, and the values ​​of n are 10-12.

3. The anti-freeze crack cable according to claim 1, characterized in that: The alkenyl silane coupling agent is at least one of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltri(diethylphosphoryloxy)silane, and γ-methacryloyloxypropyltrimethoxysilane.

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

5. The anti-freeze crack cable according to claim 4, characterized in that: The peroxide crosslinking agent is a composition of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and bis(4-methylbenzoyl)peroxide in a weight ratio of (1-1.5):

1.

6. The anti-freeze crack cable according to claim 1, characterized in that: The flame retardant is aluminum hydroxide modified with an alkenylsilane coupling agent.

7. A method for preparing a freeze-crack resistant cable as described in any one of claims 1-6, characterized in that, Includes the following steps: A filler layer is filled on the outer surface of the cable core, then a wrapping layer is wrapped around the outer surface of the filler layer, and then a shielding layer is woven on the outer surface of the wrapping layer to obtain an unsheathed cable; Methyl vinyl silicone rubber, modified filler, flame retardant, colorant, and hydroxyl silicone oil are mixed evenly at 80-100℃, then cooled to below 50℃, and a peroxide crosslinking agent is added to continue mixing to obtain silicone rubber material; The silicone rubber material is extruded onto the outer surface of the unsheathed cable at 120-150℃, and then the cable is transferred to an environment of 200-250℃ for vulcanization to obtain a freeze-crack resistant cable.

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