Water-blocking cable and preparation method and application thereof

Abstract

The invention belongs to the technical field of marine cables, and particularly relates to a water-blocking cable and a preparation method and application thereof. The water-blocking cable comprises an aluminum conductor, an inner insulating layer, an inner protective layer, a first armor layer, a composite water-blocking layer, a second armor layer and an outer sheath which are sequentially arranged from inside to outside. The composite water-blocking layer comprises a first water-blocking tape layer, a water-blocking filling layer and a second water-blocking tape layer; the water-blocking filling layer is located between the first water-blocking tape layer and the second water-blocking tape layer; and the first water-blocking tape layer or the second water-blocking tape layer is connected with the inner insulating layer. The water-blocking cable has excellent water-blocking performance and corrosion resistance, the problems that an existing cable is insufficient in water-blocking performance in the marine environment, an aluminum conductor is prone to corrosion and the like are solved, and it is ensured that the cable can stably and reliably operate for a long time in the marine environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of submarine cables, and particularly relates to a water-blocking cable, a preparation method thereof, and an application thereof. Background Art

[0002] In the field of cable water-blocking, with the continuous deepening of marine resource development, such as the construction of facilities like offshore wind farms and offshore oil exploitation platforms, the demand for submarine cables is increasing day by day. In the marine environment, cables are faced with harsh conditions such as high humidity, seawater immersion, and strong corrosion. Traditional cables are prone to problems such as a decline in insulation performance, conductor corrosion, and water tree growth in such an environment, seriously affecting the service life of the cables and the stability of power transmission.

[0003] In view of the above problems, it is necessary to carry out water-blocking treatment on cables. The methods of water-blocking treatment generally include filling water-blocking paste, setting water-blocking tapes, etc. However, in the long-term marine environment, the water-blocking effect is still not ideal enough. Especially for aluminum conductor cables, due to the relatively active chemical properties of aluminum, it is more likely to corrode in the presence of water and oxygen, thereby leading to the deterioration of cable performance.

[0004] Therefore, it is of great significance to develop an aluminum conductor cable that can effectively adapt to the marine environment and has excellent water-blocking performance. Summary of the Invention

[0005] To achieve the above object, the present invention provides a water-blocking cable, a preparation method thereof, and an application thereof. The water-blocking cable has excellent water-blocking performance and corrosion resistance, solves the problems of insufficient water-blocking performance and easy corrosion of aluminum conductors in existing cables in the marine environment, and ensures that the cable can operate stably and reliably for a long time in the marine environment.

[0006] The present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a water-blocking cable, which includes an aluminum conductor, an inner insulation layer, an inner sheath, a first armor layer, a composite water-blocking layer, a second armor layer, and an outer sheath arranged in sequence from the inside to the outside;

[0008] The composite water-blocking layer includes a first water-blocking tape layer, a water-blocking filling layer, and a second water-blocking tape layer;

[0009] The water-blocking filling layer is located between the first water-blocking tape layer and the second water-blocking tape layer;

[0010] The first water-blocking tape layer or the second water-blocking tape layer is connected to the inner insulation layer;

[0011] The material of the water-blocking filling layer includes water-blocking paste;

[0012] The water-blocking paste includes raw materials in the following weight parts:

[0013] 10 to 30 parts of sodium polyacrylate, 20 to 50 parts of bentonite, 5 to 15 parts of fiber material and 0.5 to 3 parts of antioxidant.

[0014] In some possible implementations, the thickness of the first water-blocking tape layer is 1.0 mm to 1.5 mm.

[0015] In some possible implementations, the thickness of the second water-blocking tape layer is 1.0 mm to 1.5 mm.

[0016] In some possible implementations, the material of the first water-blocking tape layer includes a first carrier and a first highly water-absorbent resin loaded on the first carrier;

[0017] The loading amount of the first highly absorbent resin is 40 g / m 2 ~50g / m 2 .

[0018] In some possible implementations, the material of the second water-blocking tape layer includes a second carrier and a second highly water-absorbent resin loaded on the second carrier;

[0019] The loading amount of the second super absorbent resin is 40 g / m 2 ~50g / m 2 .

[0020] In some possible implementations, the aluminum conductor includes aluminum and also includes rare earth elements with a mass fraction of 0.01% to 0.10%.

[0021] In some possible implementations, the surface of the aluminum conductor contains a dense oxide film layer;

[0022] The thickness of the dense oxide film layer is 0.5 μm to 1.5 μm.

[0023] In some possible implementations, the first armor layer includes a first anti-corrosion coating, a double stainless steel tape layer, and a second anti-corrosion coating;

[0024] The first anti-corrosion coating is located on one surface of the double-layer stainless steel belt layer;

[0025] The second anti-corrosion coating is located on the other surface of the double-layer stainless steel strip layer away from the first anti-corrosion coating;

[0026] The first anti-corrosion coating or the second anti-corrosion coating is attached to the inner insulating layer.

[0027] In some possible implementations, the second armor layer includes a third anti-corrosion coating, a double stainless steel tape layer, and a fourth anti-corrosion coating;

[0028] The third anti-corrosion coating is located on one surface of the double-layer stainless steel strip layer;

[0029] The fourth anti-corrosion coating is located on the other surface of the double-layer stainless steel strip layer facing away from the third anti-corrosion coating;

[0030] The third anti-corrosion coating or the fourth anti-corrosion coating is attached to the composite water-blocking layer.

[0031] In a second aspect, the present invention provides a method for manufacturing a water-blocking cable, comprising the following steps:

[0032] The inner insulation layer, the first armor layer, the composite water-blocking layer, the second armor layer and the outer sheath are sequentially coated on the aluminum conductor to obtain the water-blocking cable.

[0033] In a third aspect, the present invention provides an application of the water-blocking cable provided by the present invention in the technical field of submarine cables.

[0034] The water-blocking cable provided by the present invention, its manufacturing method and application, compared with the prior art, have at least the following beneficial technical effects:

[0035] (1) In the water-blocking cable provided by the present invention, the composite water-blocking layer includes a first water-blocking tape layer, a water-blocking filling layer and a second water-blocking tape layer with a "sandwich" structure, which can effectively prevent the intrusion of moisture. Even in an environment of long-term seawater immersion, it can ensure the dryness inside the cable and prevent problems such as the decline of insulation performance and conductor corrosion caused by moisture.

[0036] (2) In the water-blocking cable provided by the present invention, the aluminum conductor contains trace amounts of rare earth elements, which refine the grains of the aluminum conductor, improve the strength and corrosion resistance of the aluminum conductor, and extend the service life of the cable.

[0037] (3) In the water-blocking cable provided by the present invention, the surface of the aluminum conductor contains a dense oxide film, which further enhances the corrosion resistance of the aluminum conductor and extends the service life of the cable.

[0038] (4) In the water-blocking cable provided by the present invention, the armor layers (the first armor layer and the second armor layer) composed of the double-layer stainless steel strip wound by the double-layer stainless steel strip and the anti-corrosion coatings on both the inner and outer surfaces, and the outer sheath with good mechanical properties and seawater corrosion resistance provide reliable mechanical protection and excellent seawater corrosion resistance for the cable, ensuring the stable operation of the cable in a harsh marine environment. Description of the Drawings

[0039] To more clearly illustrate the technical solutions in the embodiments of the present drawings or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present drawings. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0040] Figure 1 It is a schematic cross-sectional structure diagram of the water-blocking cable in the embodiment of the present invention.

[0041] Explanation of the reference numerals in the drawings: 1 - aluminum conductor, 2 - inner insulation layer, 3 - inner sheath, 4 - first armor layer, 5 - composite water-blocking layer, 6 - second armor layer, 7 - outer sheath.

[0042] The realization of the purpose of the present drawings, functional features and advantages will be further described in conjunction with the embodiments with reference to the drawings. Specific embodiments

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clear and understandable, the following describes and explains the present invention in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0044] Obviously, the following description is only some examples or embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, the present invention can also be applied to other similar scenarios. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed by the present invention, some designs, manufacturing or production changes based on the technical content disclosed by the present invention are only conventional technical means and should not be understood as the content disclosed by the present invention being insufficient.

[0045] However, there will be cases where unnecessary detailed descriptions are omitted. For example, there are cases where the detailed descriptions of well-known matters are omitted and the repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present invention and is not intended to limit the subject matter recited in the claims.

[0046] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present invention can be combined with each other to form new technical solutions.

[0047] The following is a detailed description of a water-blocking cable and its preparation method according to an embodiment of the present invention.

[0048]

Water-blocking cable

[0049] In the first aspect of the embodiment of the present invention, a water-blocking cable is provided, as Figure 1 shown, which includes an aluminum conductor 1, an inner insulating layer 2, an inner sheath 3, a first armor layer 4, a composite water-blocking layer 5, a second armor layer 6, and an outer sheath 7 arranged in sequence from inside to outside;

[0050] The composite water-blocking layer 5 includes a first water-blocking tape layer, a water-blocking filling layer, and a second water-blocking tape layer;

[0051] The water-blocking filling layer is located between the first water-blocking tape layer and the second water-blocking tape layer;

[0052] The first water-blocking tape layer or the second water-blocking tape layer is connected to the inner insulating layer 2;

[0053] The material of the water-blocking filling layer includes water-blocking paste;

[0054] The water-blocking paste includes raw materials in the following weight parts:

[0055] 10 parts to 30 parts of sodium polyacrylate, 20 parts to 50 parts of bentonite, 5 parts to 15 parts of fiber material, and 0.5 parts to 3 parts of a first antioxidant.

[0056] For the water-blocking cable provided by the embodiment of the present invention, the composite water-blocking layer 5 includes a first water-blocking tape layer, a water-blocking filling layer, and a second water-blocking tape layer with a "sandwich" structure, which can effectively prevent the intrusion of moisture. When moisture intrudes into the water-blocking layer, the superabsorbent resin and the water-blocking paste quickly absorb water and expand, preventing further penetration of moisture. Even in an environment of long-term seawater immersion, it can ensure the dryness inside the cable and prevent problems such as a decrease in insulation performance and conductor corrosion caused by moisture. The water-blocking cable provided by the embodiment of the present invention has excellent water-blocking performance, insulation performance, mechanical performance, and seawater corrosion resistance, and can meet the power transmission requirements in the marine environment. It solves the problems of insufficient water-blocking performance and easy corrosion of the aluminum conductor 1 in the existing cable in the marine environment, and ensures that the cable can operate stably and reliably for a long time in the marine environment.

[0057] In some embodiments, in the aluminum conductor 1, it includes aluminum element and also includes rare earth elements with a mass fraction of 0.01% to 0.10%. In this case, adding rare earth elements to aluminum can refine the grains of aluminum and improve the strength and corrosion resistance of the aluminum conductor 1.

[0058] In some embodiments, the rare earth elements include at least one of lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd).

[0059] In some specific embodiments, in the aluminum conductor 1, in addition to aluminum element, it further includes cerium (Ce) with a mass fraction of 0.01% - 0.05% and lanthanum (La) with a mass fraction of 0.01% - 0.05%.

[0060] In some embodiments, in the aluminum conductor 1, the purity of aluminum is above 99.7%.

[0061] In some possible implementation manners, the diameter of the aluminum conductor 1 is 1.5 mm - 30 mm.

[0062] In some possible implementation manners, the surface of the aluminum conductor 1 contains a dense oxide film layer;

[0063] The thickness of the dense oxide film layer is 0.5 μm - 1.5 μm. In this case, the dense oxide film layer further enhances the corrosion resistance of the aluminum conductor 1.

[0064] In some embodiments, the material of the inner insulating layer 2 includes cross-linked polyethylene. In this case, cross-linked polyethylene has excellent electrical insulation properties. Its insulation resistance is very high, which can effectively reduce power loss, and it can withstand a relatively high voltage, which is crucial for long-distance submarine cable transmission, ensuring stable power transmission under the sea floor and avoiding leakage and other situations. Secondly, it has good water resistance. In the submarine environment, the cable is immersed in seawater for a long time, and cross-linked polyethylene can prevent seawater from penetrating into the cable interior and damaging the insulation performance and the cable core, and can maintain the insulation effect for a long time. At the same time, it also has anti-aging performance, can resist the erosion of chemical substances in the seawater environment and the influence of marine climate factors, and extend the service life of the submarine cable.

[0065] In some embodiments, the average molecular weight of the cross-linked polyethylene is 2×10 5 ~5×10 5 .

[0066] In some embodiments, the thickness of the inner insulating layer 2 is 1.0 mm - 10 mm.

[0067] In some embodiments, the material of the inner sheath 3 is TPE (Thermoplastic Elastomer).

[0068] In some specific embodiments, the TPE is JLS-FR331W804E produced by Hangzhou Jiersi Flame Retardant Chemical Co., Ltd.

[0069] In some embodiments, the thickness of the inner sheath 3 is 1.0 mm - 1.5 mm.

[0070] In some embodiments, the first armor layer 4 includes a first anti-corrosion coating, a double-layer stainless steel strip layer, and a second anti-corrosion coating;

[0071] The first anti-corrosion coating is located on one surface of the double-layer stainless steel strip layer;

[0072] The second anti-corrosion coating is located on the other surface of the double-layer stainless steel strip layer facing away from the first anti-corrosion coating;

[0073] The first anti-corrosion coating or the second anti-corrosion coating is attached to the inner insulation layer 2.

[0074] In the above-mentioned first armor layer 4, the double-layer stainless steel strip layer can significantly enhance the tensile strength and compressive strength of the cable, enabling the cable to withstand greater external forces, thereby improving its overall mechanical properties. It also has excellent corrosion resistance, preventing the aluminum conductor 1 in the cable from being corroded during long-term seawater immersion; the first anti-corrosion coating and the second anti-corrosion coating can further enhance the corrosion resistance of the armor layer. The armor layer can also prevent the cable from being mechanically damaged during laying or operation, ensuring the integrity of the internal structure of the cable.

[0075] In some embodiments, the material of the first anti-corrosion coating is epoxy zinc-rich paint, and the epoxy zinc-rich paint is Interzinc 52 of AkzoNobel.

[0076] In some embodiments, the thickness of the first anti-corrosion coating is 50μm - 80μm.

[0077] In some embodiments, the thickness of the double-layer stainless steel strip layer is 0.5mm - 0.8mm.

[0078] In some embodiments, the double-layer stainless steel strip layer is formed by winding double-layer stainless steel strips, and the winding gap is not greater than 40% of the width of the steel strip.

[0079] In some specific embodiments, the material of the double-layer stainless steel strip is 316L stainless steel.

[0080] In some specific embodiments, the thickness of the double-layer stainless steel strip is 0.3mm - 0.5mm.

[0081] In some embodiments, the material of the second anti-corrosion coating is epoxy zinc-rich paint, and the epoxy zinc-rich paint is Interzinc 52 of AkzoNobel.

[0082] In some embodiments, the thickness of the second anti-corrosion coating is 50μm - 80μm.

[0083] In some embodiments, the thickness of the first water-blocking tape layer is 1.0mm - 1.5mm.

[0084] In some embodiments, the thickness of the second water-blocking tape layer is 1.0 mm to 1.5 mm.

[0085] In some embodiments, the material of the first water-blocking tape layer includes a first carrier and a first superabsorbent resin loaded on the first carrier;

[0086] The loading amount of the first superabsorbent resin is 40 g / m 2 to 50 g / m 2 .

[0087] In some embodiments, the first carrier includes one of non-woven fabric and carbon fiber.

[0088] In some embodiments, the first superabsorbent resin includes raw materials with the following mass fractions: 40% to 50% ethylene-vinyl acetate copolymer, 15% to 25% bromobutyl rubber, 10% to 20% stearic acid-modified nano calcium carbonate, 5% to 10% amino silane coupling agent-modified glass fiber, 5% to 10% plasticizer, and 0.5% to 1.3% auxiliary agent.

[0089] In some specific embodiments, in the water-blocking paste, the average molecular weight of sodium polyacrylate is 5×10 5 to 2×10 6 .

[0090] In some specific embodiments, the fiber material is E-glass or S-glass of Owens Corning.

[0091] In some specific embodiments, the first antioxidant includes pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010).

[0092] In some embodiments, the thickness of the water-blocking filling layer is 0.8 mm to 1.0 mm.

[0093] In some embodiments, the material of the second water-blocking tape layer includes a second carrier and a second superabsorbent resin loaded on the second carrier;

[0094] The loading amount of the second superabsorbent resin is 40 g / m 2 to 50 g / m 2 .

[0095] In some embodiments, the second superabsorbent resin includes raw materials with the following mass fractions: 40% to 50% ethylene-vinyl acetate copolymer, 15% to 25% bromobutyl rubber, 10% to 20% stearic acid-modified nano calcium carbonate, 5% to 10% amino silane coupling agent-modified glass fiber, 5% to 10% plasticizer, and 0.5% to 1.3% auxiliary agent.

[0096] In some embodiments, the second carrier includes one of non-woven fabric and carbon fiber.

[0097] In some embodiments, in the ethylene-vinyl acetate copolymer, the content of vinyl acetate is 28% - 40%.

[0098] In some embodiments, the plasticizer includes diisononyl phthalate.

[0099] In some embodiments, the additives include a second antioxidant and an ultraviolet absorber; based on the mass of the first superabsorbent resin or the second superabsorbent resin being 100%, the mass fractions of the second antioxidant and the ultraviolet absorber are respectively:

[0100] 0.2% - 0.5% of the second antioxidant, 0.3% - 0.8% of the ultraviolet absorber.

[0101] In some specific embodiments, the second antioxidant includes pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (antioxidant 1010). In this case, antioxidant 1010 is a highly efficient hindered phenol antioxidant that can effectively inhibit the oxidative degradation of the polymer during processing and use, and extend the service life of the water-blocking tape. Multiple hindered phenol groups in its molecular structure can capture free radicals, interrupt the oxidative chain reaction, and protect the polymer molecular chain from being damaged.

[0102] In some specific embodiments, the ultraviolet absorber includes UV-531. In this case, UV-531 can strongly absorb ultraviolet light with wavelengths in the range of 270nm - 340nm, convert it into heat energy and release it, thereby effectively preventing the polymer from aging and degrading due to ultraviolet irradiation, and ensuring that the water-blocking cable can still maintain good performance after long-term use in outdoor environments.

[0103] In some embodiments, the second armor layer 6 includes a third anti-corrosion coating, a double-layer stainless steel tape layer, and a fourth anti-corrosion coating;

[0104] The third anti-corrosion coating is located on one surface of the double-layer stainless steel tape layer;

[0105] The fourth anti-corrosion coating is located on the other surface of the double-layer stainless steel tape layer facing away from the third anti-corrosion coating;

[0106] The third anti-corrosion coating or the fourth anti-corrosion coating is attached to the composite water-blocking layer 5.

[0107] In the above-mentioned second armor layer 6, the double-layer stainless steel tape layer can significantly enhance the tensile strength and compressive strength of the cable, enabling the cable to withstand greater external forces, thereby improving its overall mechanical properties. It also has excellent corrosion resistance, preventing the aluminum conductor 1 in the cable from being corroded during long-term seawater immersion. The third anti-corrosion coating and the second anti-corrosion coating can further enhance the corrosion resistance of the armor layer. The armor layer can also prevent the cable from being mechanically damaged during laying or operation, ensuring the integrity of the internal structure of the cable.

[0108] In some embodiments, the material of the third anti-corrosion coating is epoxy zinc-rich paint, and the epoxy zinc-rich paint is Amercoat391, PPG Industries.

[0109] In some embodiments, the thickness of the third anti-corrosion coating is 50μm - 80μm.

[0110] In some embodiments, the thickness of the double-layer stainless steel tape layer is 0.3mm - 0.5mm.

[0111] In some embodiments, the double-layer stainless steel tape layer is formed by winding double-layer stainless steel tapes, and the winding gap is not greater than 40% of the width of the steel tape.

[0112] In some specific embodiments, the material of the double-layer stainless steel tape is 316L stainless steel.

[0113] In some embodiments, the material of the fourth anti-corrosion coating is epoxy zinc-rich paint, and the epoxy zinc-rich paint is Amercoat391, PPG Industries.

[0114] In some embodiments, the thickness of the fourth anti-corrosion coating is 50μm - 80μm.

[0115] In some embodiments, the material of the outer sheath 7 is TPE (Thermo-Plastic Elastomer). In this case, TPE has good resistance to ultraviolet rays, ozone, and hydrolysis, and can resist the effects of ultraviolet irradiation, ozone erosion, and long-term seawater immersion in the marine environment, ensuring the stable performance of the submarine cable outer sheath during long-term use. Secondly, it has good chemical corrosion resistance: it can withstand the erosion of seawater, salt spray, and various chemicals in the ocean, preventing the outer sheath 7 from being corroded and damaged, and extending the service life of the submarine cable. The TPE material has high elasticity and rebound shrinkage rate similar to rubber, enabling the submarine cable to withstand a certain degree of external forces such as stretching, bending, and torsion during laying and use, and is not easily damaged by external forces.

[0116] In some specific embodiments, the TPE is JLS-FR331W804E produced by Hangzhou Jiersi Flame Retardant Chemical Co., Ltd.

[0117] In some embodiments, the thickness of the outer sheath 7 is 2.5 mm to 4.5 mm.

[0118]

Preparation Method of Water-blocking Cable

[0119] The second aspect of the embodiments of the present invention provides a preparation method of the water-blocking cable provided by the embodiments of the present invention, including the following steps:

[0120] S1. The inner insulating layer 2, the inner sheath 3, the first armor layer 4, the composite water-blocking layer 5, the second armor layer 6, and the outer sheath 7 are sequentially coated on the aluminum conductor 1 to obtain a water-blocking cable.

[0121] In some embodiments, in the above step S1, the preparation of the aluminum conductor 1 includes the following steps:

[0122] S101. The aluminum conductor 1 is surface-treated to obtain an aluminum conductor 1 with a dense oxide film layer on its surface.

[0123] In some embodiments, in the above step S101, the surface treatment includes the following steps: The aluminum conductor 1 is immersed in a mixed treatment solution, and anodic oxidation treatment is carried out for 20 min to 30 min under the conditions of a temperature of 20°C to 30°C and a current density of 1 A / dm 2 ~2 A / dm 2 ;

[0124] Among them, the mixed treatment solution contains phosphoric acid, sulfuric acid, and an additive, and the mass ratio is (3 to 5):(2 to 4):1.

[0125] In some embodiments, the concentration of phosphoric acid is 10% to 20%.

[0126] In some embodiments, the concentration of sulfuric acid is 15% to 20%.

[0127] In some embodiments, the additive is oxalic acid. In this case, oxalic acid can refine the oxide film structure and improve the surface density.

[0128] In some embodiments, in the above step S1, the preparation of the composite water-blocking layer 5 includes the following steps:

[0129] S102. The raw materials of the first carrier, the first superabsorbent resin, the second carrier, the second superabsorbent resin, and the water-blocking paste are respectively obtained.

[0130] S103. After the first superabsorbent resin is coated on the first carrier and dried, a first water-blocking tape layer is obtained;

[0131] After the second superabsorbent resin is coated on the second carrier and dried, a second water-blocking tape layer is obtained.

[0132] S104. Fill the water-blocking paste between the first water-blocking tape layer and the second water-blocking tape layer and dry it to obtain the composite water-blocking layer 5.

[0133] In some embodiments, in the above step S102, preparing the water-blocking paste includes the following steps:

[0134] Mix and stir the raw materials of the water-blocking paste evenly;

[0135] The raw materials of the water-blocking paste include sodium polyacrylate, bentonite, fiber material and the first antioxidant.

[0136] In some embodiments, in the above step S103, when preparing the first water-blocking tape layer, the drying temperature is 70°C to 90°C.

[0137] In some embodiments, in the above step S103, when preparing the second water-blocking tape layer, the drying temperature is 70°C to 90°C.

[0138] In some embodiments, in the above step S104, the drying temperature is 70°C to 90°C.

[0139] The following is further described with specific embodiments.

[0140] For the convenience of comparison, in the following examples and comparative examples, unless otherwise specified, the materials involved are as follows:

[0141] (1) Aluminum conductor:

[0142] ① The aluminum conductor is composed of the following components by mass fraction: 0.03% cerium (Ce), 0.04% lanthanum (La), and the balance is aluminum (Al) and inevitable impurities.

[0143] ② The thickness of the dense oxide film on the surface of the aluminum conductor is 1 μm, and the surface treatment steps are as follows: Immerse the aluminum conductor in the mixed treatment solution and perform anodic oxidation treatment for 25 minutes at a temperature of 25°C and a current density of 1.5 A / dm 2 under the condition of;

[0144] Among them, the mixed treatment solution contains phosphoric acid, sulfuric acid and oxalic acid (concentration about 1%), and the mass ratio is 4:3:1; the concentration of phosphoric acid is 15%, and the concentration of sulfuric acid is 18%.

[0145] (2) Inner insulating layer: The material of the inner insulating layer is cross-linked polyethylene with an average molecular weight of 3×10 5 and a thickness of 2 ± 0.5 mm.

[0146] (3) Inner sheath: The material is TPE (Thermoplastic Elastomer); TPE is JLS-FR331W804E produced by Hangzhou Jiersi Flame Retardant Chemical Co., Ltd.; the thickness is 1.0 mm to 1.5 mm.

[0147] (4) The first armor layer and the second armor layer:

[0148] ① The materials of the first anti-corrosion coating and the second anti-corrosion coating are both Interzinc 52 of AkzoNobel, and the materials of the third anti-corrosion coating and the fourth anti-corrosion coating are both Amercoat 391, PPG Industries; the thickness is 60 μm.

[0149] ② The material of the double-layer stainless steel tape is 316L stainless steel, and the winding gap is 25% of the width of the steel tape.

[0150] (5) Composite water-blocking layer:

[0151] ① The water-blocking paste is composed of the following components by weight: 20 parts of sodium polyacrylate, 30 parts of bentonite, 10 parts of fiber material and 1 part of antioxidant 1010; the average molecular weight of sodium polyacrylate is 2×10 6 .

[0152] ② Both the first superabsorbent resin and the second superabsorbent resin are composed of the following components by mass fraction: 45% ethylene-vinyl acetate copolymer, 22.2% brominated butyl rubber, 18% stearic acid-modified nano calcium carbonate, 9% amino silane coupling agent-modified glass fiber, 5% diisononyl phthalate, 0.3% antioxidant 1010, 0.5% UV-531; among them, the content of vinyl acetate in the ethylene-vinyl acetate copolymer is 30%, and the bromine content of the brominated butyl rubber is 2.1%.

[0153] ③ The materials of the first carrier and the second carrier are both non-woven fabrics.

[0154] ④ The loading amounts of the first superabsorbent resin and the second superabsorbent resin are both 25 g / m 2 .

[0155] (6) Outer sheath: The material of the outer sheath is TPE, and the thickness is 3 mm.

[0156] Example 1

[0157] Example 1 provides a water-blocking cable, which is composed of an aluminum conductor, an inner insulating layer, an inner sheath, a first armor layer, a composite water-blocking layer, a second armor layer and an outer sheath arranged in sequence from inside to outside;

[0158] The composite water-blocking layer is composed of a first water-blocking tape layer, a water-blocking filling layer and a second water-blocking tape layer;

[0159] The water-blocking filling layer is located between the first water-blocking tape layer and the second water-blocking tape layer;

[0160] The first water-blocking tape layer is connected to the inner insulating layer.

[0161] Among them, the thickness of the water-blocking filling layer is 0.8 mm; the thicknesses of the first water-blocking tape layer and the second water-blocking tape layer are both 1.5 mm.

[0162] Example 2

[0163] Example 2 provides a water-blocking cable, the structure of which is basically the same as that of Example 1, except that:

[0164] The thickness of the water-blocking filling layer is 0.9 mm; the thicknesses of the first water-blocking tape layer and the second water-blocking tape layer are both 1.5 mm.

[0165] Example 3

[0166] Example 3 provides a water-blocking cable, the structure of which is basically the same as that of Example 1, except that:

[0167] The thickness of the water-blocking filling layer is 1.0 mm; the thicknesses of the first water-blocking tape layer and the second water-blocking tape layer are both 1.3 mm.

[0168] Comparative Example 1

[0169] Comparative Example 1 provides a water-blocking cable, which is composed of an aluminum conductor, an inner insulating layer, a first armor layer, a water-blocking layer, a second armor layer, and an outer sheath arranged in sequence from the inside to the outside;

[0170] The materials and thicknesses of the aluminum conductor, the inner insulating layer, the first armor layer, the second armor layer, and the outer sheath are the same as those in Example 1;

[0171] The water-blocking layer is a single water-blocking tape layer, which is composed of non-woven fabric and superabsorbent resin loaded on the non-woven fabric;

[0172] The superabsorbent resin is composed of the following component raw materials by mass fraction: 45% ethylene-vinyl acetate copolymer, 22.2% bromobutyl rubber, 18% stearic acid-modified nano calcium carbonate, 9% amino silane coupling agent-modified glass fiber, 5% diisononyl phthalate, 0.3% antioxidant 1010, 0.5% UV-531; among them, the content of vinyl acetate in the ethylene-vinyl acetate copolymer is 30%, and the bromine content of the bromobutyl rubber is 2.1%;

[0173] The loading amount of the superabsorbent resin is 25 g / m 2 .

[0174] Comparative Example 2

[0175] Comparative Example 2 provides a water-blocking cable, whose structural components are basically the same as those of Example 1, except that:

[0176] The water-blocking layer is composed of two water-blocking tape layers, and both of the two water-blocking tape layers are composed of non-woven fabric and superabsorbent resin loaded on the non-woven fabric;

[0177] The component raw materials and loading amount of the superabsorbent resin are the same as those of Comparative Example 1.

[0178] Comparative Example 3

[0179] Comparative Example 3 provides a water-blocking cable, which is composed of an aluminum conductor, an inner insulating layer, a composite water-blocking layer, an armor layer and an outer sheath arranged in sequence from inside to outside.

[0180] The materials and thicknesses of the aluminum conductor, the inner insulating layer, the composite water-blocking layer and the outer sheath are the same as those of Example 1;

[0181] The armor layer is wound by 316L stainless steel tape, and the winding gap is 25% of the width of the steel tape (i.e., without an anti-corrosion coating).

[0182] To verify the progressiveness of the water-blocking cable and its preparation method of the embodiment of the present invention, water-blocking performance, insulation performance, mechanical performance and seawater corrosion resistance tests are carried out on the water-blocking cables provided by the examples and comparative examples, and the test results are shown in Table 1 below.

[0183] The test contents are as follows:

[0184] (1) Water-blocking performance

[0185] Water permeability (24h):

[0186] According to IEC60811-504, the cable is aged in an environment of 85°C and 85% RH (relative humidity environment) for 7 days;

[0187] Then the cable is immersed in deionized water with a water depth of 1m and a temperature of 20°C for 24h, and the water absorption per unit length of the cable (g / m) is measured.

[0188] (2) Insulation performance

[0189] Volume resistivity (20°C): According to the standard GB / T30483, the resistivity of the insulating layer (Ω·m) is detected.

[0190] (3) Mechanical performance

[0191] ① Tensile strength: According to the standard GB / T2951.11, the tensile strength (kN) in the axial direction of the cable is detected.

[0192] ② Bending test: The cable is bent 10 times around a cylinder with a diameter of 20D (D is the outer diameter of the cable), and the cracking or delamination of the armor layer is checked.

[0193] (4) Seawater corrosion resistance

[0194] Salt spray test (3000 h): Test the cable without outer sheath (to detect the corrosion resistance of the second armor layer / armor layer) according to ASTM B117, where the concentration of sodium chloride solution is 5%, and the spray temperature is 35°C.

[0195] Table 1

[0196]

[0197] At least the following conclusions can be drawn from Table 1 above:

[0198] (1) For the water-blocking cables provided by the examples and comparative examples, after aging for seven days, the water absorption rates of Examples 1-3 are still relatively low; while the water absorption rates of Comparative Examples 1-3 are relatively high. Thus, it can be seen that the water-blocking cables provided by the examples of the present invention have high water-blocking performance. The "sandwich" structure of the first water-blocking tape layer, water-blocking filling layer and second water-blocking tape layer in the composite water-blocking layer can effectively prevent the intrusion of moisture. When moisture intrudes into the water-blocking layer, the superabsorbent resin and water-blocking paste quickly absorb water and swell to prevent further penetration of moisture.

[0199] (2) For the water-blocking cables provided by the examples and comparative examples, the resistivity of the examples is relatively large, indicating that the insulation performance of the water-blocking cables provided by the examples of the present invention has also been improved.

[0200] (3) The water-blocking cables provided by the examples and comparative examples have relatively large tensile strength, and there is no obvious cracking or delamination in the armor layer after bending 10 times, indicating that the water-blocking cables provided by the examples of the present invention have excellent mechanical properties. The armor layer can prevent the cable from being mechanically damaged during laying or operation, and ensure the integrity of the internal structure of the cable.

[0201] (4) For the water-blocking cables provided by the examples and comparative examples, after the salt spray corrosion test, there is no rust on the second armor layer on the outer layer of the water-blocking cables of Examples 1-3 and Comparative Examples 1-2, and the oxide film is intact; while the armor layer of Comparative Example 3 is locally rusted and the oxide film falls off; thus, it can be seen that the water-blocking cables provided by the examples of the present invention have excellent corrosion resistance, preventing the aluminum conductor in the cable from being corroded during long-term seawater immersion; the third anti-corrosion coating and the second anti-corrosion coating can further enhance the corrosion resistance of the armor layer.

[0202] It should be noted that the present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having the same constitution as the technical idea and exhibiting the same effects within the scope of the technical solution of the present invention are all included in the technical scope of the present invention. In addition, within the scope not departing from the gist of the present invention, various modifications that can be conceived by those skilled in the art to the embodiments, and other modes constructed by combining some constituent elements in the embodiments are also included in the scope of the present invention.

Claims

1. A water-blocking cable, characterized in that, It includes an aluminum conductor, an inner insulating layer, an inner sheath, a first armor layer, a composite water-blocking layer, a second armor layer, and an outer sheath, which are arranged in sequence from the inside to the outside; The composite water-blocking layer includes a first water-blocking tape layer, a water-blocking filling layer, and a second water-blocking tape layer; The water-blocking filling layer is located between the first water-blocking tape layer and the second water-blocking tape layer; The first water-blocking tape layer or the second water-blocking tape layer is connected to the inner insulating layer; The material of the water-blocking filling layer includes water-blocking paste; The water-blocking paste includes raw materials in the following weight parts: 10 parts to 30 parts of sodium polyacrylate, 20 parts to 50 parts of bentonite, 5 parts to 15 parts of fiber material, and 0.5 parts to 3 parts of antioxidant.

2. The water-blocking cable according to claim 1, characterized in that, The thickness of the first water-blocking tape layer and the thickness of the second water-blocking tape layer can be independently 1.0 mm to 1.5 mm respectively.

3. The water-blocking cable according to claim 1 or 2, characterized in that The material of the first water-blocking tape layer includes a first carrier and a first superabsorbent resin loaded on the first carrier; The loading amount of the first superabsorbent resin is 40 g / m 2 ~50 g / m 2 .

4. The water-blocking cable according to claim 3, wherein The material of the second water-blocking tape layer includes a second carrier and a second superabsorbent resin loaded on the second carrier; The loading amount of the second superabsorbent resin is 40 g / m 2 to 50 g / m 2 .

5. The water-blocking cable according to claim 1, characterized in that, In the aluminum conductor, it includes aluminum element and also includes rare earth elements with a mass fraction of 0.01% to 0.10%; 6. The water-blocking cable according to any one of claims 1, 2, 4, and 5, characterized in that, The surface of the aluminum conductor contains a dense oxide film layer; The thickness of the dense oxide film layer is 0.5 μm to 1.5 μm.

7. The water-blocking cable according to claim 6, wherein, The first armor layer includes a first anti-corrosion coating, a double-layer stainless steel tape layer, and a second anti-corrosion coating; The first anti-corrosion coating is located on one surface of the double-layer stainless steel tape layer; The second anti-corrosion coating is located on the other surface of the double-layer stainless steel tape layer facing away from the first anti-corrosion coating; The first anti-corrosion coating or the second anti-corrosion coating is attached to the inner insulating layer; 8. The water-blocking cable according to claim 7, wherein, The second armor layer includes a third anti-corrosion coating, a double-layer stainless steel tape layer, and a fourth anti-corrosion coating; The third anti-corrosion coating is located on one surface of the double-layer stainless steel tape layer; The fourth anti-corrosion coating is located on the other surface of the double-layer stainless steel tape layer facing away from the third anti-corrosion coating; The third anti-corrosion coating or the fourth anti-corrosion coating is attached to the composite water-blocking layer; 9. A method for preparing a water-blocking cable according to any one of claims 1 to 8, characterized in that, It includes the following steps: Sequentially wrap the inner insulating layer, the first armor layer, the composite water-blocking layer, the second armor layer, and the outer sheath on the aluminum conductor to obtain the water-blocking cable.

10. Application of a water-blocking cable as described in any one of claims 1 to 8 in the technical field of submarine cables.

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