High-strength rodent-proof optical cable and preparation method thereof

Abstract

The application discloses a kind of high-strength rat-proof optical cable and preparation method thereof, including at least one reinforcing member, at least one cable core distributed outside the reinforcing member, an inner protective layer coated outside the cable core, an armored layer coated outside the inner protective layer, a rat-proof outer sheath coated outside the armored layer, wherein the cable core is composed of at least one optical fiber and loose tube;Wherein, by weight parts, the rat-proof outer sheath is made of the following raw materials: linear low density polyethylene 70-80 parts, nylon 12 20-30 parts, compatibilizer 5-8 parts, modified composite filler 15-20 parts, antioxidant 1-3 parts, lubricant 0.5-1 part.The high-strength rat-proof optical cable uses LLDPE / nylon 12 alloy matrix with a specific formula in the outer sheath, and introduces modified composite filler, so that the finally prepared optical cable outer sheath not only has excellent mechanical strength, wear resistance, realizes efficient, long-acting and environment-friendly biological rat-proof effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical cable, and particularly relates to a high-strength rat-proof optical cable and a preparation method thereof. BACKGROUND

[0002] As the core infrastructure of modern information society, optical cable is a communication cable that uses optical fiber as transmission medium and is coated and protected by a series of precise processes. With its incomparable advantages such as large transmission capacity, low attenuation loss, strong anti-electromagnetic interference ability and good confidentiality, it has been widely used in long-distance trunk communication, metropolitan area network, data center interconnection and even fiber to the home (FTTH) and other fields, and has become the cornerstone of the global information superhighway. In order to ensure that the optical fiber can work stably for a long time in complex actual environment, the optical cable structure usually contains multiple protection levels such as reinforcing member, loose tube, filling paste and sheath to resist the influence of external factors such as stretching, lateral pressure, bending and temperature change.

[0003] However, in actual deployment and long-term operation, the protection ability of the existing ordinary optical cable still faces severe challenges. Especially in the environment where rodents are active frequently, such as in the wild, pipelines, rural areas and warehouses, the gnawing of rodents and other animals has become one of the main reasons for the damage of optical cable and the interruption of communication. In order to solve this problem, the industry has developed various rat-proof optical cable technologies. One common method is to add a chemical aversive agent, such as a bittering agent, to the sheath material, which uses the taste that rodents hate to prevent gnawing. However, the effect of this method is discounted due to the tolerance difference of individual rodents, and its long-term effectiveness is questionable. Another method is to use physical protection, such as adding a metal armor layer (such as steel belt or steel wire) to the optical cable structure, or using a special engineering plastic (such as nylon) with extremely high hardness as a sheath.

[0004] Chinese patent application CN104371191A discloses a special material for anti-biting and anti-mouse communication cable sheath pipe and a preparation method thereof, which is made of the following raw materials by weight: polypropylene 52-76, ethylene-trifluoro chlorovinyl copolymer 31-43, benzyl benzoate 3-6, allyl diglycol dicarbonate 4-6, cycloheximide 2-4, lead sulfate 3-5, dicyclohexyl phthalate 10-15, spherical quartz sand 16-22, tin triphenyl acetate 2-4, m-chloroaniline 1.5-2.5, dibutyl azelate 5-10, monophenyl diisodecyl phosphite 2-3, chlorinated paraffin 4-8, barium metatitanate 8-14, coated red phosphorus 5-10, phenethyl m-diphenol 1-2, and auxiliary agent 4.5-6.5. The special material for sheath pipe of the present application adds benzyl benzoate, tin triphenyl acetate, m-chloroaniline and other substances, which can greatly improve the anti-biting and anti-mouse performance of the sheath pipe, effectively prevent the invasion of insects and mice on the sheath pipe, ensure the safe and normal operation of the optical cable, and have excellent wear resistance, weather resistance, corrosion resistance and temperature resistance, long service life and wide application range. Chinese patent application CN113793724A discloses a cross-linked polyethylene insulation environment-friendly anti-mouse and anti-termite flame-retardant control cable, belonging to the technical field of cables. The cable comprises a copper conductor, the outer surface of the copper conductor is coated with a cross-linked polyethylene insulation layer, the copper conductor and the cross-linked polyethylene insulation layer form a cable core, seven cable cores form a group, the outer layer of the group of cable cores is wound with a polyester tape to form a wrapped polyester tape layer, the wrapped polyester tape layer is coated with a copper wire braid layer, the outer surface of the copper wire braid layer is coated with an anti-mouse and anti-termite flame-retardant polyolefin sheath; the anti-mouse and anti-termite flame-retardant polyolefin sheath is made of an anti-mouse and anti-termite flame-retardant polyolefin material, and an anti-mouse and anti-termite agent is added during preparation of the anti-mouse and anti-termite flame-retardant polyolefin material; the anti-mouse and anti-termite component in the anti-mouse and anti-termite agent prepared by the present application is a nonivamide-based anti-mouse and anti-termite agent, which belongs to synthetic capsaicin. The difference from the prior art is that the anti-mouse and anti-termite agent not only has the effect of preventing mice and termites, but also has a certain flame-retardant effect. However, the above-mentioned patents directly add anti-mouse agents to the sheath material by physical mixing method, but with long-term use, on the one hand, the sheath material will age and the material performance will decrease, making it more easily damaged by mice; on the other hand, the anti-mouse agent may precipitate, thereby losing the anti-mouse effect.

[0005] Therefore, it is of great significance to develop a high-strength optical cable with long anti-mouse time. SUMMARY

[0006] In view of the shortcomings of the prior art, the purpose of the present application is to provide a high-strength anti-mouse optical cable and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A high-strength rat-proof optical cable, comprising at least one reinforcing member, at least one cable core distributed outside the reinforcing member, an inner protective layer wrapped outside the cable core, an armored layer wrapped outside the inner protective layer, and a rat-proof outer sheath wrapped outside the armored layer, wherein the cable core is composed of at least one optical fiber and a loose tube;

[0009] The rat-proof outer sheath is made of the following raw materials in parts by weight: linear low-density polyethylene 70-80 parts, nylon 12 20-30 parts, a compatibilizer 5-8 parts, modified composite fillers 15-20 parts, an antioxidant 1-3 parts, and a lubricant 0.5-1 part.

[0010] In the present application, the LLDPE / nylon 12 alloy matrix with a specific formula is used in the outer sheath, and the modified composite fillers are creatively introduced, so that the finally prepared optical cable outer sheath not only has excellent mechanical strength, wear resistance and processing fluidity, but also realizes high-efficiency, long-term and environmentally friendly biological rat-proof effect through the chemical functionalization design of the fillers.

[0011] Preferably, the preparation method of the modified composite fillers comprises the following steps:

[0012] S1, adding nano-silicon dioxide into an ethanol aqueous solution, then adding γ-glycidoxypropyltrimethoxysilane, stirring and reacting, filtering, washing and drying after the reaction is completed to obtain pretreated silicon dioxide;

[0013] S2, adding composite silicon dioxide into deionized water, then adding hydroxypropyl-β-cyclodextrin and triethylamine, heating and reacting, filtering, washing and drying after the reaction is completed to obtain a solid product, then adding the solid product into DMF, then adding 6-mercaptopyridine-3-carboxylic acid, N,N'-dicyclohexyl carbodiimide and 4-dimethylaminopyridine, constant-temperature reacting, filtering, washing and drying after the reaction is completed to obtain organic silicon dioxide;

[0014] S3, adding the organic silicon dioxide in step S2 into toluene, then adding erucamide and azobisisobutyronitrile, performing mercapto-olefin reaction, filtering, washing and drying after the reaction is completed to obtain composite silicon dioxide;

[0015] S4, adding capsaicin into ethanol, stirring uniformly, then adding the composite silicon dioxide in step S3, stirring and adsorbing, filtering and drying after the adsorption is completed to obtain modified composite fillers.

[0016] Preferably, the mass ratio of the nano-silicon dioxide and γ-glycidoxypropyltrimethoxysilane in step S1 is 80-90:7-10, the stirring and reaction temperature is 50-60℃, and the time is 3-4h.

[0017] In the present application, the modified composite filler takes nano-silica as the skeleton, which has a huge specific surface area, can provide enough reaction sites and interaction area with the matrix at a small addition amount, and at the same time, its inherent high hardness and high modulus provide the basic rigidity and strength for the sheath material; the nano-silica is reacted with γ-glycidoxypropyltrimethoxysilane to introduce epoxy groups on the surface of the nano-silica, which is not only beneficial to the subsequent reaction, but also improves the interfacial compatibility of the filler and the sheath material matrix.

[0018] Preferably, the mass ratio of the composite silica, hydroxypropyl-β-cyclodextrin and triethylamine in step S2 is 80-90:10-15:3-5, the temperature of the heating reaction is 60-70℃, and the time is 5-7h; the mass ratio of the solid product, 6-mercaptopyridine-3-carboxylic acid, N,N'-dicyclohexyl carbodiimide and 4-dimethylaminopyridine is 90-100:8-12:10-15:1-2, and the temperature of the constant temperature reaction is 60-70℃, and the time is 4-7h.

[0019] In the present application, the hydroxypropyl-β-cyclodextrin is introduced onto the silica by the reaction of the epoxy groups on the composite silica and the hydroxyl groups on the hydroxypropyl-β-cyclodextrin, so that the subsequently added rodent repellent (capsaicin) can be included and released slowly, and the hydroxypropyl-β-cyclodextrin is introduced in a chemical bonding manner, which can ensure its uniform dispersion in the sheath material and also reduce its subsequent precipitation, achieving long-acting rodent prevention effect of the sheath material; then the silica with the introduced hydroxypropyl-β-cyclodextrin is subjected to esterification reaction with 6-mercaptopyridine-3-carboxylic acid, which introduces high-activity sulfydryl groups on one hand, providing the possibility for subsequent grafting of long-chain molecules, and on the other hand, due to the presence of the pyridine ring, can complex the metal ions produced in the degradation process, playing the role of auxiliary antioxidant, delaying the aging of the sheath material, improving the weather resistance of the sheath, and thus prolonging the long-acting rodent prevention function of the optical cable.

[0020] Preferably, the mass ratio of the organicized silica, erucamide and azobisisobutyronitrile in step S3 is 90-100:7-10:0.5-0.8, and the temperature of the mercapto-olefin reaction is 70-80℃, and the time is 1-2h.

[0021] In the present application, the erucamide is introduced onto the organicized silica through mercapto-olefin reaction, thereby avoiding the problem of insufficient compatibility of the hydroxypropyl-β-cyclodextrin introduced on the silica with LLDPE in the sheath material, and the erucamide has a hydrophobic fatty long chain similar to the structure of polyethylene, which can physically entangle and embed into the molecular chain of LLDPE, firmly fixing the filler in the matrix through the "physical anchoring" effect, greatly improving the interfacial bonding force, and thus significantly improving the impact strength and toughness of the sheath material; at the same time, the erucamide itself is also a lubricant, which can improve the processing fluidity.

[0022] Preferably, in step S4, the mass ratio of capsaicin, ethanol, and composite silica is 7-10:600-700:90-100, and the stirring and adsorption temperature is 40-50℃ for 3-4 hours.

[0023] In this invention, capsaicin, a natural and highly effective biostimulant, is introduced into the modified composite filler through the inclusion effect of hydroxypropyl-β-cyclodextrin, thereby achieving a long-lasting, efficient, low-migration, and environmentally friendly rodent-proof effect on optical cables.

[0024] Preferably, the compatibilizer is maleic anhydride-grafted POE.

[0025] Preferably, the antioxidant is one or more of antioxidant 168, antioxidant 1098, and antioxidant 1010; the lubricant is silicone masterbatch.

[0026] Preferably, the preparation method of the rodent-proof outer sheath includes the following steps: weighing linear low-density polyethylene, nylon 12, compatibilizer, modified composite filler, antioxidant, and lubricant according to the formula, adding them to a high-speed mixer, mixing them evenly, and then adding the mixture to a twin-screw extruder, extruding and granulating it at 190-240℃ to obtain the product.

[0027] This invention also protects a method for preparing a high-strength rodent-proof optical cable as described above, comprising the following steps:

[0028] Step 1: Fabricating colored optical fibers: The bare optical fibers are colored into different colors;

[0029] Step 2: Cable core fabrication: Loose tubes are formed using a secondary coating extruder, and colored optical fibers of different colors are placed into the loose tubes and wound to form a single cable core.

[0030] Step 3: Multiple cable cores are bundled together: The reinforcing member and multiple cable cores are bundled together in a stranding machine, with the reinforcing member in the center and the multiple cable cores outside the reinforcing member;

[0031] Step 4: Fabrication of inner sheath and armor layer: Extruding low-density polyethylene, medium-density polyethylene or high-density polyethylene material over the multiple cable cores formed in step 3 to form an inner sheath, and weaving aluminum tape around the inner sheath to form an armor layer.

[0032] Step 5: Fabricate the rodent-proof outer sheath: Extrude the rodent-proof outer sheath over the armor layer using an extruder to obtain the high-strength rodent-proof optical cable.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) The high-strength rat-proof optical cable provided by the application adopts a specific formula of LLDPE / nylon 12 alloy matrix in the outer sheath, and creatively introduces a modified composite filler, so that the finally prepared optical cable outer sheath not only has excellent mechanical strength, wear resistance and processing fluidity, but also realizes high-efficiency, long-acting and environment-friendly biological rat-proof effect through the chemical functionalization design of the filler; the filler is uniformly dispersed in the matrix, has good interfacial compatibility with the high molecular matrix, and cooperatively improves the strength and tear resistance of the material, and at the same time, imparts excellent weather resistance and service life to the outer sheath, thereby ensuring long-term, stable and reliable operation of the optical cable in complex outdoor environments.

[0035] (2) The high-strength rat-proof optical cable provided by the application solves the problems of easy migration, easy failure and influence on material performance of the traditional rat-proof agent through multi-step chemical reactions; with nano-silicon dioxide as the core, cyclodextrin with inclusion ability, mercaptopyridine carboxylic acid for connecting subsequent functional groups are grafted in turn, and long-chain erucic acid amide is connected through efficient mercapto-alkene click chemistry reaction, this structure firmly anchors the functional components on the filler, and stores the rat-proof active substances in the cavity of cyclodextrin through inclusion, realizes slow release of the rat-proof agent, greatly prolongs the effective period of the rat-proof function, and ensures that the active ingredients will not pollute the environment or affect other layer structures of the optical cable due to migration; and 6-mercaptopyridine-3-carboxylic acid is ingeniously used as a bridge molecule, one end of which is connected to cyclodextrin through a stable ester bond, and the other end exposes a highly active mercapto group, which enables subsequent grafting of erucic acid amide through mild reaction conditions, high yield and no by-products, the introduction of the long carbon chain of erucic acid amide not only improves the interfacial compatibility of the filler and the LLDPE / nylon matrix as a lubricating and compatibilizing component, but more importantly, the terminal amide structure can form a hydrogen bond with the molecular chain of nylon 12, acting as a physical crosslinking point, further enhancing the toughness and interlayer bonding force of the composite material.

[0036] (3) The high-strength rat-proof optical cable provided by the application uses molecular inclusion technology to load rat-proof active substances (capsaicin), compared with traditional physical blending, the hydrophobic inner cavity and hydrophilic outer wall of cyclodextrin are used to efficiently include the hydrophobic small molecules of capsaicin in the cavity, this inclusion not only greatly improves the dispersion stability of these active substances in aqueous and polar environments, but more importantly, forms a micro “molecular capsule”, when the bite of rodents destroys the inclusion balance, the active substances are slowly released, thereby realizing the slow release effect of the active substances, reducing unnecessary loss of active substances to the minimum while ensuring the rat-proof effect, and prolonging the rat-proof time of the optical cable. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1The structural schematic diagram of the high-strength rat-proof optical cable.

[0038] In the figure, 1, reinforcing member; 2, cable core; 3, loose tube; 4, optical fiber; 5, inner protective layer; 6, armored layer; 7, rat-proof outer sheath. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0040] Unless otherwise specified, the chemical reagents and materials in the present application are purchased through market channels or synthesized from raw materials purchased through market channels.

[0041] The brand of the linear low-density polyethylene is Exxon Mobil LL 7020YB; the brand of the nylon 12 is Arkema 35R53 SP01 from France; the particle size of the nano-silicon dioxide is 200-300 nm; the brand of the maleic anhydride grafted POE is Mitsui MA8510, and the grafting rate is 1%.

[0042] Embodiment 1

[0043] A high-strength rat-proof optical cable comprises at least one reinforcing member 1, at least one cable core 2 distributed outside the reinforcing member 1, an inner protective layer 5 wrapped outside the cable core, an armored layer 6 wrapped outside the inner protective layer, and a rat-proof outer sheath 7 wrapped outside the armored layer, wherein the cable core 2 is composed of at least one optical fiber 4 and a loose tube 3.

[0044] The rat-proof outer sheath is made of the following raw materials in parts by weight: linear low-density polyethylene 75 parts, nylon 12 25 parts, maleic anhydride grafted POE 7 parts, modified composite filler 18 parts, anti-antioxidant 1098 2 parts, and silicone master batch 0.8 part.

[0045] The preparation method of the modified composite filler comprises the following steps:

[0046] S1, 85 g of nano-silicon dioxide is added to 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), then 9 g of γ-glycidoxypropyltrimethoxysilane is added, and stirring reaction is carried out at 55℃ for 3.5 h. After the reaction is completed, the product is filtered, washed, and dried to obtain pretreated silicon dioxide;

[0047] S2, 85 g of pretreated silica is added to 1.3 L of deionized water, then 13 g of hydroxypropyl-β-cyclodextrin, 4 g of triethylamine are added, and the reaction is carried out at 65°C for 6 h. After the reaction is completed, filtration, washing and drying are carried out to obtain a solid product, and then 95 g of the solid product is added to 1.5 L of DMF, then 10 g of 6-mercaptopyridine-3-carboxylic acid, 13 g of N,N'-dicyclohexyl carbodiimide, 1.5 g of 4-dimethylaminopyridine are added, and the reaction is carried out at 65°C for 6 h. After the reaction is completed, filtration, washing and drying are carried out to obtain organic modified silica;

[0048] S3, 95 g of organic modified silica in step S2 is added to 1.5 L of toluene, then 9 g of erucic acid amide, 0.7 g of azobisisobutyronitrile are added, and the reaction is carried out at 75°C for 1.5 h. After the reaction is completed, filtration, washing and drying are carried out to obtain composite silica;

[0049] S4, 9 g of capsaicin is added to 650 g of ethanol, stirred uniformly, and then 95 g of composite silica in step S3 is added, and the adsorption is carried out at 45°C for 3.5 h. After the adsorption is completed, filtration and drying are carried out to obtain a modified composite filler.

[0050] The preparation method of the rat-proof outer sheath comprises the following steps: linear low density polyethylene, nylon 12, maleic anhydride grafted POE, modified composite filler, antioxidant 1098 and silicone master batch are weighed according to the formula amount, added into a high-speed mixer, mixed uniformly, then the mixture is added into a double-screw extruder, and extrusion granulation is carried out at 230°C, and the rat-proof outer sheath is obtained.

[0051] Example 2

[0052] A high-strength rat-proof optical cable comprises at least one reinforcing member 1, at least one cable core 2 distributed outside the reinforcing member 1, an inner protective layer 5 wrapped outside the cable core, an armor layer 6 wrapped outside the inner protective layer, and a rat-proof outer sheath 7 wrapped outside the armor layer, wherein the cable core 2 is composed of at least one optical fiber 4 and a loose tube 3;

[0053] The rat-proof outer sheath is prepared from the following raw materials in parts by weight: linear low density polyethylene 80 parts, nylon 12 20 parts, maleic anhydride grafted POE 5 parts, modified composite filler 15 parts, antioxidant 1098 1 part, and silicone master batch 0.5 part.

[0054] The preparation method of the modified composite filler comprises the following steps:

[0055] S1, 80 g of nano-silica is added to 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 4:1), then 7 g of γ-glycidoxypropyltrimethoxysilane is added, and the reaction is carried out at 50°C for 4 h. After the reaction is completed, filtration, washing and drying are carried out to obtain pretreated silica.

[0056] S2, 80 g of pretreated silica is added to 1.3 L of deionized water, then 10 g of hydroxypropyl-β-cyclodextrin, 3 g of triethylamine are added, and the reaction is carried out at 60°C for 7 h. After the reaction is completed, filtration, washing, and drying are performed to obtain a solid product. Then, 90 g of the solid product is added to 1.5 L of DMF, then 8 g of 6-mercaptopyridine-3-carboxylic acid, 10 g of N,N'-dicyclohexyl carbodiimide, 1 g of 4-dimethylaminopyridine are added, and the reaction is carried out at 60°C for 7 h. After the reaction is completed, filtration, washing, and drying are performed to obtain organicized silica;

[0057] S3, 90 g of the organicized silica in step S2 is added to 1.5 L of toluene, then 6 g of erucic acid amide, 0.5 g of azobisisobutyronitrile are added, and the reaction is carried out at 70°C for 2 h. After the reaction is completed, filtration, washing, and drying are performed to obtain composite silica;

[0058] S4, 7 g of capsaicin is added to 600 g of ethanol, and after being stirred uniformly, 90 g of the composite silica in step S3 is added, and the adsorption is carried out at 40°C for 4 h. After the adsorption is completed, filtration and drying are performed to obtain a modified composite filler.

[0059] The preparation method of the rat-proof outer sheath includes the following steps: linear low-density polyethylene, nylon 12, maleic anhydride grafted POE, modified composite filler, antioxidant 1098, and silicone master batch are weighed according to the formula amount, added to a high-speed mixer, uniformly mixed, then the mixture is added to a double-screw extruder, and extrusion granulation is carried out at 230°C, and the rat-proof outer sheath is obtained.

[0060] Example 3

[0061] A high-strength rat-proof optical cable includes at least one reinforcing member 1, at least one cable core 2 distributed outside the reinforcing member 1, an inner protective layer 5 wrapped outside the cable core, an armor layer 6 wrapped outside the inner protective layer, and a rat-proof outer sheath 7 wrapped outside the armor layer, wherein the cable core 2 is composed of at least one optical fiber 4 and a loose tube 3;

[0062] The rat-proof outer sheath is made of the following raw materials in parts by weight: linear low-density polyethylene 70 parts, nylon 12 30 parts, maleic anhydride grafted POE 8 parts, modified composite filler 20 parts, antioxidant 1098 3 parts, and silicone master batch 1 part.

[0063] The preparation method of the modified composite filler includes the following steps:

[0064] S1, 90 g of nano-silica was added into 1 L of ethanol aqueous solution (volume ratio of ethanol to water was 4:1), then 10 g of γ-glycidoxypropyltrimethoxysilane was added, and the mixture was stirred and reacted at 60°C for 3 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated silica;

[0065] S2, 90 g of the pretreated silica was added into 1.3 L of deionized water, then 15 g of hydroxypropyl-β-cyclodextrin and 5 g of triethylamine were added, and the mixture was reacted at 70°C for 5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a solid product. Then, 100 g of the solid product was added into 1.5 L of DMF, then 12 g of 6-mercaptopyridine-3-carboxylic acid, 15 g of N,N'-dicyclohexyl carbodiimide, and 2 g of 4-dimethylaminopyridine were added, and the mixture was reacted at 70°C for 4 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain organically modified silica;

[0066] S3, 100 g of the organically modified silica in step S2 was added into 1.5 L of toluene, then 10 g of erucic acid amide and 0.8 g of azobisisobutyronitrile were added, and the mixture was reacted at 80°C for 1 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite silica;

[0067] S4, 10 g of capsaicin was added into 700 g of ethanol, and the mixture was stirred to be uniform. Then, 100 g of the composite silica in step S3 was added, and the mixture was stirred and adsorbed at 50°C for 3 h. After the adsorption was completed, the mixture was filtered and dried to obtain modified composite filler.

[0068] The preparation method of the rat-proof outer sheath comprises the following steps: linear low-density polyethylene, nylon 12, maleic anhydride grafted POE, modified composite filler, antioxidant 1098, and silicone master batch are weighed according to the formula amount, added into a high-speed mixer, uniformly mixed, then the mixture is added into a double-screw extruder, and the mixture is extruded and granulated at 230°C to obtain the rat-proof outer sheath.

[0069] Comparative Example 1

[0070] A high-strength rat-proof optical cable comprises at least one reinforcing member 1, at least one cable core 2 distributed outside the reinforcing member 1, an inner protective layer 5 wrapped outside the cable core, an armor layer 6 wrapped outside the inner protective layer, and a rat-proof outer sheath 7 wrapped outside the armor layer, wherein the cable core 2 is composed of at least one optical fiber 4 and a loose tube 3;

[0071] The rat-proof outer sheath is prepared from the following raw materials in parts by weight: linear low-density polyethylene 75 parts, nylon 12 25 parts, maleic anhydride grafted POE 7 parts, modified composite filler 18 parts, antioxidant 1098 2 parts, and silicone master batch 0.8 part.

[0072] The preparation method of the modified composite filler comprises the following steps:

[0073] S1, 85 g of nano-silica was added into 1 L of ethanol aqueous solution (volume ratio of ethanol to water was 4:1), then 9 g of γ-glycidoxypropyltrimethoxysilane was added, and the mixture was stirred and reacted at 55°C for 3.5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated silica;

[0074] S2, 85 g of the pretreated silica was added into 1.3 L of deionized water, then 13 g of hydroxypropyl-β-cyclodextrin and 4 g of triethylamine were added, and the mixture was reacted at 65°C for 6 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain organically modified silica;

[0075] S3, 95 g of the organically modified silica in step S2 was added into 1.5 L of toluene, then 9 g of erucamide and 0.7 g of azobisisobutyronitrile were added, and the mixture was reacted at 75°C for 1.5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite silica;

[0076] S4, 9 g of capsaicin was added into 650 g of ethanol, and the mixture was stirred to be uniform. Then 95 g of the composite silica in step S3 was added, and the mixture was stirred and adsorbed at 45°C for 3.5 h. After the adsorption was completed, the mixture was filtered and dried to obtain modified composite filler.

[0077] The preparation method of the rat-proof outer sheath comprises the following steps: linear low-density polyethylene, nylon 12, maleic anhydride grafted POE, modified composite filler, antioxidant 1098, and silicone master batch are weighed according to the formula amount, added into a high-speed mixer, uniformly mixed, then the mixture is added into a double-screw extruder, and extruded and granulated at 230°C to obtain the rat-proof outer sheath.

[0078] Compared with Example 1, the present comparative example does not introduce 6-mercapto-pyridine-3-carboxylic acid into the modified composite filler.

[0079] Comparative Example 2

[0080] A high-strength rat-proof optical cable comprises at least one reinforcing member 1, at least one cable core 2 distributed outside the reinforcing member 1, an inner protective layer 5 wrapped outside the cable core, an armor layer 6 wrapped outside the inner protective layer, and a rat-proof outer sheath 7 wrapped outside the armor layer, wherein the cable core 2 is composed of at least one optical fiber 4 and a loose tube 3.

[0081] The rat-proof outer sheath is made of the following raw materials in parts by weight: linear low-density polyethylene 75 parts, nylon 12 25 parts, maleic anhydride grafted POE 7 parts, modified composite filler 18 parts, antioxidant 1098 2 parts, and silicone master batch 0.8 parts.

[0082] The preparation method of the modified composite filler comprises the following steps:

[0083] S1, 85 g of nano-silica was added into 1 L of ethanol aqueous solution (volume ratio of ethanol to water was 4:1), then 9 g of γ-glycidoxypropyltrimethoxysilane was added, and the mixture was stirred and reacted at 55°C for 3.5 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain pretreated silica;

[0084] S2, 85 g of the pretreated silica was added into 1.3 L of deionized water, then 13 g of hydroxypropyl-β-cyclodextrin and 4 g of triethylamine were added, and the mixture was reacted at 65°C for 6 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain a solid product. Then, 95 g of the solid product was added into 1.5 L of DMF, then 10 g of 6-mercaptopyridine-3-carboxylic acid, 13 g of N,N'-dicyclohexyl carbodiimide, and 1.5 g of 4-dimethylaminopyridine were added, and the mixture was reacted at 65°C for 6 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain organically modified silica.

[0085] S3, 9 g of capsaicin was added into 650 g of ethanol, and the mixture was stirred and mixed uniformly. Then, 95 g of the organically modified silica in step S2 was added, and the mixture was stirred and adsorbed at 45°C for 3.5 h. After the adsorption was completed, the mixture was filtered and dried to obtain a modified composite filler.

[0086] The preparation method of the rat-proof outer sheath included the following steps: linear low-density polyethylene, nylon 12, maleic anhydride grafted POE, modified composite filler, antioxidant 1098, and silicone master batch were weighed according to the formula amount, added into a high-speed mixer, and mixed uniformly. Then, the mixture was added into a twin-screw extruder, and extruded and granulated at 230°C to obtain the rat-proof outer sheath.

[0087] Compared with Example 1, the comparative example did not introduce erucamide into the modified composite particles.

[0088] The rat-proof outer sheath prepared from Example 1-3 and Comparative Example 1-2 is prepared into a sample strip for performance testing. The tensile strength and elongation at break are tested according to GB / T 2951.11-2008 "Cable and optical cable insulation and sheath materials - General test methods - Part 11: General test methods - Measurement of thickness and outer dimensions - Mechanical property tests". The aging test is performed according to GB / T 2951.12-2008 "Cable and optical cable insulation and sheath materials - General test methods - Part 12: General test methods - Heat aging test methods", the aging temperature is 100℃±2℃, the air exchange rate is 15 times per hour, and the test time is 240 hours. The rat bite resistance test: the rat-proof outer sheath prepared from Example 1-3 and Comparative Example 1-2 is dried in a 105℃ air oven for 6 hours, and the dried particles are injected into a 150mm×30mm rectangular sheet sample on an injection molding machine. 20 test rats, half male and half female and healthy (no missing upper and lower teeth), are respectively fed in the rat cages, one test rat is fed in one rat cage, and the related requirements of the test rats and the rat cages refer to the standard of GB / T 29199-2012 "Optical cable rat resistance performance test method". The sample is placed in the rat cage, and after 7 days, the total number of tooth marks in the 20 rat cages is recorded, the tooth marks include single tooth marks and double tooth marks, and the test rats are normally fed during the test period. The sample placement, tooth mark recording and test rat feeding operation refer to the standard of GB / T 29199-2012 "Optical cable rat resistance performance test method". The rat resistance rating evaluation standard is: 1st grade, total tooth mark number≤5; 2nd grade, 5<total tooth mark number≤10; 3rd grade, 10<total tooth mark number≤20; 4th grade, 20<total tooth mark number≤30; 5th grade, 30<total tooth mark number≤50; 6th grade, total tooth mark number>50. The rat bite resistance performance of the rat-proof outer sheath before and after aging is tested. The test results are shown in Table 1.

[0089] Table 1 Performance test results of rat-proof outer sheaths of various groups

[0090]

[0091] As can be seen from the above table, the rat-proof outer sheath prepared by the present application has good mechanical properties, and also has good long-term rat resistance performance, thereby improving the strength and rat resistance performance of the optical cable.

[0092] The above content is a further detailed description of the present application in combination with specific implementation examples, and cannot be considered as limiting the specific implementation of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present application, and all of them should be considered as falling within the protection scope of the present application.

[0093] Those skilled in the art can easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high strength rodent resistant optical cable characterized by, The cable includes at least one reinforcing member (1), at least one cable core (2) distributed outside the reinforcing member (1), an inner protective layer (5) wrapped outside the cable core, an armored layer (6) wrapped outside the inner protective layer, and a rat-proof outer sheath (7) wrapped outside the armored layer, wherein the cable core (2) is composed of at least one optical fiber (4) and a loose tube (3); The rat-proof outer sheath is made of the following raw materials in parts by weight: linear low-density polyethylene 70-80 parts, nylon 12 20-30 parts, a compatible agent 5-8 parts, modified composite filler 15-20 parts, antioxidant 1-3 parts, and lubricant 0.5-1 part. The preparation method of the modified composite filler comprises the following steps: S1, adding nano-silicon dioxide into an ethanol aqueous solution, then adding γ-glycidoxypropyltrimethoxysilane, and stirring to obtain pretreated silicon dioxide; S2, adding the pretreated silicon dioxide into deionized water, then adding hydroxypropyl-β-cyclodextrin and triethylamine, and heating to obtain a solid product, then adding the solid product into DMF, and then adding 6-mercaptopyridine-3-carboxylic acid, N,N'-dicyclohexyl carbodiimide and 4-dimethylaminopyridine, and constant temperature reaction to obtain organic silicon dioxide; S3, adding the organic silicon dioxide into toluene, then adding erucamide and azobisisobutyronitrile, and performing mercapto-olefin reaction to obtain composite silicon dioxide; S4, adding capsaicin into ethanol, stirring to obtain a uniform mixture, then adding the composite silicon dioxide, and stirring to adsorb, then filtering and drying to obtain the modified composite filler.

2. The high strength rodent resistant optical cable of claim 1, wherein, In step S1, the mass ratio of the nano-silicon dioxide and the γ-glycidoxypropyltrimethoxysilane is 80-90:7-10, the stirring reaction is performed at a temperature of 50-60°C for 3-4 hours.

3. The high strength rodent resistant optical cable of claim 1, wherein, In step S2, the mass ratio of the pretreated silicon dioxide, the hydroxypropyl-β-cyclodextrin and the triethylamine is 80-90:10-15:3-5, the heating reaction is performed at a temperature of 60-70°C for 5-7 hours, the mass ratio of the solid product, the 6-mercaptopyridine-3-carboxylic acid, the N,N'-dicyclohexyl carbodiimide and the 4-dimethylaminopyridine is 90-100:8-12:10-15:1-2, and the constant temperature reaction is performed at a temperature of 60-70°C for 4-7 hours.

4. The high strength rodent resistant optical cable of claim 1, wherein, In step S3, the mass ratio of the organic silicon dioxide, the erucamide and the azobisisobutyronitrile is 90-100:7-10:0.5-0.8, and the mercapto-olefin reaction is performed at a temperature of 70-80°C for 1-2 hours.

5. The high strength rodent resistant optical cable of claim 1, wherein, In step S4, the mass ratio of the capsaicin, the ethanol and the composite silicon dioxide is 7-10:600-700:90-100, and the stirring adsorption is performed at a temperature of 40-50°C for 3-4 hours.

6. The high strength rodent resistant optical cable of claim 1, wherein, The compatible agent is maleic anhydride grafted POE.

7. The high strength rodent resistant optical cable of claim 1, wherein, The antioxidant is one or more of antioxidant 168, antioxidant 1098 and antioxidant 1010, and the lubricant is silicone master granules.

8. The high strength rodent resistant optical cable of claim 1, wherein, The preparation method of the rat-proof outer sheath comprises the following steps: linear low-density polyethylene, nylon 12, a compatibilizer, modified composite filler, an antioxidant and a lubricant are weighed according to the formula amount, added into a high-speed mixer and uniformly mixed, then the mixture is added into a double-screw extruder, and extruded and granulated at 190-240 DEG C to obtain the rat-proof outer sheath.

9. A process for the production of a high strength rodent resistant optical cable as claimed in any one of claims 1 to 8, characterised in that, The method comprises the following steps: Step one, making colored optical fibers: bare optical fibers are colored into colored optical fibers of different colors; Step two, making cable cores: loose sleeves are formed through a secondary coating extruder, and the colored optical fibers of different colors are placed into the loose sleeves to form single cable cores through winding; Step three, combining multiple cable cores: a reinforcing member and multiple cable cores are combined into a cable in a stranding machine, so that the reinforcing member is located in the center and the multiple cable cores are located outside the reinforcing member; Step four, making an inner protective layer and an armor layer: low-density polyethylene or medium-density polyethylene or high-density polyethylene material is extruded to coat the multiple cable cores formed in step three to form an inner protective layer, and aluminum belts are braided outside the inner protective layer to form an armor layer; Step five, making a rat-proof outer sheath layer: an extruder is used to extrude and coat a rat-proof outer sheath outside the armor layer to obtain the high-strength rat-proof optical cable.

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