A sensor optical cable for detecting vibration

Abstract

The invention discloses a sensor optical cable for detecting vibrations, which belongs to the technical field of communication cables. The sensor optical cable for detecting vibrations of the invention comprises, from the inside to the outside, an inner layer of sensing optical fiber, a TPEE casing, an inner layer of water-blocking fiber paste, a PBT casing, an outer layer of water-blocking fiber paste and an outer sheath; the inner layer of water-blocking fiber paste and the outer layer of water-blocking fiber paste are both optical fiber filling pastes; the optical fiber filling paste is prepared from paraffin-based hydrogenated white oil, poly-α-olefin synthetic oil, epoxy vinyl silicone oil, oil separation inhibitor, polyisobutylene material, siloxane-modified polyvinyl alcohol, organic ammonium-modified bentonite, acetylacetonate iron and an antioxidant; the sensor optical cable for detecting vibrations of the invention has a simple structure, and has excellent mechanical strength, toughness, gas barrier properties, waterproofness, corrosion resistance, high and low temperature resistance, wear resistance, aging resistance and flame retardancy, etc., and can still ensure high stability and high sensitivity of optical fiber vibration detection in harsh environments such as underwater or underground, thereby extending the service life of the sensor optical cable.

Description

Technical Field

[0001] The invention belongs to the technical field of communication cables, and in particular relates to a sensor optical cable for detecting vibration and a filling paste for its optical fiber. Background Art

[0002] With the development of communication optical cables, the application of sensor optical cables is very extensive. my country has a vast territory, with high mountains, rivers and lakes; the climate is changeable, with severe winters, high temperatures and humidity, wind and sun, ants and birds. In order to adapt to the requirements of laying methods and operating environments, the structure of optical cables is constantly developing. Today, as humans enter the information society, people have more urgent requirements for information extraction, processing, transmission and integration. As a functional device for information extraction, the relationship between sensor optical cables and humans is getting closer and closer. Sensing technology is an important part of modern information technology and one of the core technologies representing the country's scientific and technological competitiveness.

[0003] At present, a kind of sensing optical cable for detecting vibration in the prior art needs to have extremely high sensitivity in the field of optical fiber sensing. The interior of the sensing optical cable should completely block the entry of air to prevent the reflected light from being refracted and scattered in the air, block the erosion of moisture, and avoid the decline of transmission performance, which affects normal use. At the same time, in the process of detecting vibration, in order to detect vibration signals and reduce signal loss, the protective layer of the optical fiber should not be too much or too thick and needs to be directly buried. For optical cables with relatively weak armor, direct burial will be repeatedly impacted by vibration, resulting in deformation or even damage, and the service life is short. In the prior art, the optical fiber of the sensing optical cable for detecting vibration is provided with grease, plastic sheath, reinforcement and other structures on the periphery of the optical fiber to protect the optical fiber, so as to prevent the optical fiber from being broken and damaged, and to protect the optical fiber from being eroded by the external environment, and to protect the transmission performance and sensitivity of the optical cable.

[0004] Fiber optic filling paste is mainly filled between the cable core and the sheath. It plays a role of sealing, waterproofing, moisture-proofing and buffering protection in the sensor optical cable, and is one of the determining factors for the long-term stability of the optical cable performance. However, under harsh environmental conditions such as the seabed, hydrogen-containing, and cold, the existing fiber optic filling paste is long-term eroded by water, high and low temperatures, hydrogen, etc., and its waterproof, anti-corrosion, and airtightness properties are all affected, thereby reducing the transmission stability and reliability of the optical cable, affecting the detection effect and the service life of the optical cable. Conventional filling pastes mainly include water-repellent paste and water-swelling paste. The water-repellent paste mainly uses the hydrophobicity of the material itself to block moisture, air, etc. However, the current filling process cannot guarantee a 100% filling rate. Once the outer sheath of the optical cable is damaged or corroded, external moisture, gas and its harmful components will enter the interior of the optical cable from the residual gaps, destroying the cable core, and thus affecting the transmission performance of the optical cable; the water-swelling paste absorbs moisture and retains water by adding a desiccant, thereby achieving the effect of water blocking the optical cable. The filling rate of more than 70% can achieve the expected water-blocking purpose, but once the optical cable absorbs water and expands, the local optical cable will be immersed in the cable paste after water absorption for a long time, which will have an adverse effect on the quality of the optical cable, and some components in the paste may precipitate after water absorption, thereby affecting the water-blocking effect of the paste, and ultimately affecting the transportability and service life of the optical cable.

[0005] Invention patent CN201010137136.9 discloses an environmentally friendly semi-dry high water-absorbing and swelling water-blocking paste, whose components are: refined white mineral oil, delamination inhibitor, double-layer thermoplastic structure microspheres, antioxidant, polymer water-absorbing and swelling agent and silica. It has the advantages of light weight, easy filling and easy cleaning. However, the polymer water-absorbing and swelling agent is an acrylate, which makes it easy to form white powder on the surface of the paste under the influence of multiple factors such as moisture or pressure. In addition, the compatibility of hydrophilic silica with refined white mineral oil is poor, and the dispersibility of silica in the water-blocking paste is poor, which in turn affects the quality and use effect of the patented product. Invention patent CN201010290309.0 discloses a water-repellent cold-applied optical fiber filling paste for optical cables, the components of which are: base oil, tackifier, oil separation inhibitor, thickener, antioxidant, thickener and anti-emulsifier, and it has the characteristics of high and low temperature resistance, salt water resistance, anti-emulsification, and high thixotropic index value. However, its filling process has high requirements, and if it is under extreme temperature and humidity conditions, it is easy to affect its sealing and protection effect. Therefore, the quality and life of the optical cable are affected. Summary of the invention

[0006] The main purpose of the present invention is to provide a sensor optical cable for detecting vibrations, which has a simple layer structure and has excellent mechanical strength, toughness, gas barrier properties, waterproofness, corrosion resistance, high and low temperature resistance, wear resistance, aging resistance and flame retardancy, etc. It can still ensure high stability and high sensitivity of optical fiber seismic detection in harsh environments such as underwater or underground, thereby extending the service life of the sensor optical cable.

[0007] In order to achieve the purpose of the present invention, the present invention provides a sensor optical cable for detecting vibration, comprising a sensor cable core and a protective layer outside the sensor cable core, wherein the sensor cable core is a tight-sleeved optical fiber composed of a sensor optical fiber and a TPEE sleeve wrapped outside the sensor optical fiber, and the protective layer comprises, from inside to outside, an inner layer of water-blocking fiber paste, a PBT sleeve, an outer layer of water-blocking fiber paste and an outer sheath;

[0008] The inner layer water-blocking fiber paste and the outer layer water-blocking fiber paste are both optical fiber filling pastes, which are made of the following raw materials in parts by weight: 0-70 parts of paraffin-based hydrogenated white oil, 0-70 parts of poly-α-olefin synthetic oil, 10-30 parts of epoxy vinyl silicone oil, 2-5 parts of oil separation inhibitor, 3-8 parts of polyisobutylene material, 8-15 parts of siloxane-modified polyvinyl alcohol, 5-15 parts of organic ammonium-modified bentonite, 0.1-0.3 parts of ferric acetylacetonate and 0.5-2.0 parts of antioxidant;

[0009] The preparation method of the silicone-modified polyvinyl alcohol comprises the following steps:

[0010] S1. The polyvinyl alcohol was dissolved in deionized water, and then 1 wt% nanocellulose solution was added and stirred at room temperature for 1-2 h to obtain a pretreated polyvinyl alcohol mixture;

[0011] S2. Add the double-terminal carboxyl silicone oil to toluene and stir for 0.5-1h, then add it to the above polyvinyl alcohol mixture, react at 65-85°C for 3-4h under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol at least 3 times, and then place it in a 90-110°C oven to dry for 6-8h to obtain siloxane-modified polyvinyl alcohol.

[0012] Furthermore, the raw materials of the outer layer of water-blocking fiber paste also include 5-20 parts by mass of polymer water-absorbing material.

[0013] Furthermore, the polymer water-absorbing material is sodium polyacrylate or chitosan grafted modified polyacrylamide.

[0014] Furthermore, the polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of (3-5):1.

[0015] Furthermore, the viscosity average molecular weight of the medium molecular weight polyisobutylene is 40000-55000, the molecular weight of the high activity low molecular weight polyisobutylene is 900-1150, and the α-olefin content is ≥80%.

[0016] Further, the ratio of the polyvinyl alcohol to the nanocellulose solution is 0.08-0.15 g / mL;

[0017] The added amount of the double-terminal carboxyl silicone oil is 10-18% of the mass of the polyvinyl alcohol.

[0018] Furthermore, the preparation method of the optical fiber filling paste specifically comprises the following steps:

[0019] P1. Add paraffin-based hydrogenated white oil and poly-α-olefin synthetic oil to a reactor and mix, heat to 150-170°C, remove impurities and moisture, and obtain a mixed oil A;

[0020] P2. Add epoxy vinyl silicone oil, 1 / 3 mass fraction of oil separation inhibitor and 1 / 2 mass fraction of polyisobutylene material to the above mixed oil A, stir at 150-180°C for 0.5-1h, cool to 25±5°C, and obtain mixed oil B;

[0021] P3. The siloxane-modified polyvinyl alcohol, the remaining 2 / 3 mass parts of the oil separation inhibitor and the remaining 1 / 2 mass parts of the polyisobutylene material are added to the mixed oil B, stirred at 80-90 ° C, and cooled to 40 ± 5 ° C to obtain a mixture C;

[0022] P4. Add organic ammonium modified bentonite, ferric acetylacetonate and antioxidant to mixture C, stir evenly to obtain optical fiber filling paste.

[0023] Furthermore, the outer diameter of the TPEE sleeve is 2.0±0.1 mm, the wall thickness is 0.5±0.1 mm, and the TPEE sleeve is made of TPEE material with a Poisson's ratio of <0.5;

[0024] The outer diameter of the PBT sleeve is 5.0±0.3 mm, and the wall thickness is 0.5±0.1 mm;

[0025] The outer diameter of the outer sheath is 8.0±0.5 mm, the wall thickness is 1.0±0.1 mm, and the outer sheath is made of HDPE material.

[0026] The present invention has achieved the following beneficial effects:

[0027] The sensor optical cable for detecting vibrations of the present invention is prepared from the inside out by a sensor optical fiber, a TPEE casing, an inner layer of water-blocking fiber paste, a PBT casing, an outer layer of water-blocking fiber paste and an HDPE outer sheath, and has excellent waterproofness and gas barrier properties. It also has excellent mechanical strength, corrosion resistance, aging resistance, flame retardancy, and high and low temperature resistance. Moreover, when detecting vibrations in extremely harsh environments, the sensor optical cable of the present invention still has extremely high sensitivity and transmission stability of the sensor optical fiber.

[0028] The sensing optical cable of the present invention adopts a double-layer water-blocking fiber paste structure, which makes the present invention have better gas barrier properties, waterproof and moisture-proof properties, and buffering protection effects, reduces the loss of the sensing optical fiber, and improves the transmission stability of the detection vibration signal; at the same time, the water-blocking filling paste used in the present invention has low density, good compatibility between the components, and is not easy to precipitate under extreme environments. It has excellent water barrier properties, air tightness, high and low temperature resistance, thixotropy, and low hydrogen evolution degree. All technical indicators meet the national standard requirements for water-blocking pastes.

[0029] The raw materials of the sleeve, outer sheath, etc. of the present invention are easily available and environmentally friendly, which can ensure that the present invention can remain unchanged under extreme environmental conditions. It has excellent mechanical strength, elasticity, resilience, low-temperature flexibility, weather resistance, friction resistance, etc., ensuring that the sensing optical fiber can operate stably and has a service life of up to 30-40 years.

[0030] The vibration detection optical sensor cable prepared by the present invention has few layers, simple structure, easy operation in the manufacturing process, excellent waterproofness and airtightness, high optical fiber sensitivity, and can be used in extreme environments such as high temperature and seabed; the raw materials are environmentally friendly, meet the requirements of energy saving, and are environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of an embodiment of a sensor optical cable for detecting vibrations of the present invention.

[0032] Figure symbols: 1. Sensing optical fiber; 2. TPEE casing; 3. Inner layer of water-blocking fiber paste; 4. PBT casing; 5. Outer layer of water-blocking fiber paste; 6. Outer sheath. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1 As shown, the present invention provides a sensing optical cable for detecting vibrations, including a sensing cable core and a protective layer outside the sensing cable core, wherein the sensing cable core is a tight-sleeved optical fiber composed of a sensing optical fiber 1 and a TPEE sleeve 2 wrapped around the sensing optical fiber 1, and the protective layer includes, from the inside to the outside, an inner layer of water-blocking fiber paste 3, a PBT sleeve 4, an outer layer of water-blocking fiber paste 5 and an outer sheath 6.

[0035] Preferably, the inner layer water-blocking fiber paste 3 and the outer layer water-blocking fiber paste 5 are both water-blocking and air-tight optical fiber filling pastes. The optical fiber filling paste is made of the following raw materials in parts by weight: 0-70 parts of paraffin-based hydrogenated white oil, 0-70 parts of poly-α-olefin synthetic oil, 10-30 parts of epoxy vinyl silicone oil, 2-5 parts of oil separation inhibitor, 3-8 parts of polyisobutylene material, 8-15 parts of siloxane-modified polyvinyl alcohol, 5-15 parts of organic ammonium-modified bentonite, 0.1-0.3 parts of ferric acetylacetonate and 0.5-2.0 parts of antioxidant.

[0036] The optical fiber filling paste of the present invention is based on paraffin-based hydrogenated white oil, poly-α-olefin synthetic oil and epoxy vinyl silicone oil. The three base oils are used in different proportions and have good compatibility, so that the prepared filling paste can meet the rheological properties and yield strength of different requirements. At the same time, the low-temperature softness, high and low temperature resistance and temperature viscosity of the filling paste are improved, so that the filling paste has better waterproof and moisture-proof properties and stability, and extends the service life and application range of the sensor optical cable. The raw material combination and proportion of the optical fiber filling paste ensure that the optical fiber filling paste of the present invention has excellent elasticity, water resistance, high and low temperature resistance, air tightness, thixotropy, low hydrogen evolution degree, etc., and has excellent comprehensive performance; it interacts with the various component structures of the sensor optical cable, so that it can ensure the transmission stability of the optical fiber of the optical cable of the present invention and the sensitivity of detecting vibration under extreme environments.

[0037] Specifically, in the embodiment of the present invention, the paraffin-based hydrogenated white oil is 150N base oil; the poly-α-olefin synthetic oil is selected from etus PAO of Chevron; and the epoxy vinyl silicone oil is selected from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.

[0038] Preferably, the raw materials of the outer layer of water-blocking fiber paste 5 also include 5-20 parts of polymer water-absorbing materials by weight. When the outer layer of water-blocking fiber paste 5 is added with polymer water-absorbing materials, the outer layer of water-blocking fiber paste 5 integrates water-blocking and water-absorbing materials, and expands rapidly after encountering water, effectively blocking the water seepage channel, that is, the two layers of water-blocking fiber paste (the inner layer of water-blocking fiber paste 3 is a water-repellent optical fiber filling paste, and the outer layer of water-blocking fiber paste 5 is a water-absorbing and swelling optical fiber filling paste) have better water-blocking and air-tightness, and also have excellent oleophilic swelling and suspension thixotropy. When the outer layer of water-blocking fiber paste 5 is not added with polymer water-absorbing materials, the double-layer water-blocking fiber paste of the present invention is all water-repellent optical fiber filling paste, that is, the inner layer of water-blocking fiber paste 3 is a water-repellent water-blocking fiber paste, and the outer layer of water-blocking fiber paste 5 is also a water-repellent optical fiber filling paste. The double-layer water-blocking fiber paste can ensure that the present invention has better water-blocking and air-tightness, and the water-blocking performance is stable.

[0039] Specifically, the polymer water-absorbing material is sodium polyacrylate or chitosan grafted modified polyacrylamide. When sodium polyacrylate is used as a water-absorbing agent, it has super high water absorption capacity and excellent water retention capacity in the optical fiber filling paste, and the water loss is very small even under external force extrusion. However, under the action of multiple factors such as voltage and moisture or pressure and moisture, white powder will precipitate from the outer layer of water-blocking fiber paste 5, which is easy to diffuse to the adjacent layer structure to cause corrosion, thereby affecting the use effect of the sensor optical cable of the present invention (but this process is a long erosion process, and the effect on the sensor optical cable is not great over a long period of time). When the homemade chitosan grafted modified polyacrylamide of the present invention is used as a water-absorbing agent, it not only ensures that it has better compatibility with other components of the optical fiber filling paste, but also has similar water absorption capacity and water retention capacity as sodium polyacrylate, and under the action of multiple factors such as pressure or voltage under humid conditions, it will not react or precipitate to affect its water absorption and water retention capacity, thereby ensuring the transmission performance and sensitivity of the sensor optical cable of the present invention and extending the service life of the present invention.

[0040] In the embodiment of the present invention, the preparation method of the homemade chitosan grafted modified polyacrylamide is as follows: 1g chitosan and 2.5g acrylic acid are added to 80mL 1wt% acetic acid solution, stirred until dissolved, and then 10g acrylamide is added and mixed evenly, nitrogen is passed for 30min, the temperature is raised to 55°C under a nitrogen atmosphere, 0.03g potassium persulfate initiator is added, the reaction is performed for 2-4h, and the reaction is cooled to room temperature. The obtained product is dehydrated with anhydrous ethanol for 6-8h, filtered, washed with anhydrous ethanol for 3-4 times, and then placed in a 60°C oven for drying for 3-5h, and taken out to obtain the desired chitosan grafted modified polyacrylamide.

[0041] It is worth noting that by adjusting the ratio of chitosan and polyacrylamide, the degree of grafting and other parameters, the performance and function (compatibility, water retention, water absorption, etc.) of chitosan grafted modified polyacrylamide can be adjusted. Therefore, the performance of the products obtained by modifying the components in different ratios is also different. The technicians of the present invention have found through experiments with different raw material ratios and parameters that the chitosan grafted modified polyacrylamide obtained by the above preparation method can better react with the optical fiber filling paste of the present invention, which can ensure that the outer layer of the water-blocking fiber paste 5 of the present invention has better water absorption and water retention, and is not easy to precipitate under extreme environments, so that the present invention has better signal transmission and service life.

[0042] Preferably, the oil separation inhibitor of the present invention is SEBS G1702H of Kraton, USA, which can significantly improve the high and low temperature stability and oxidation resistance of the optical fiber filling paste of the present invention, effectively reduce the oil separation of the paste under extreme conditions without affecting the fluidity of the paste, and ensure the comprehensive performance of the sensor optical cable of the present invention.

[0043] Preferably, the polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of (3-5):1. Among them, the viscosity average molecular weight of the medium molecular weight polyisobutylene is 40000-55000, the molecular weight of the high activity low molecular weight polyisobutylene is 900-1150, and the α-olefin content is ≥80%. The use of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene can improve the viscosity index of the optical fiber filling paste, not only improve the viscosity stability of the optical fiber filling paste at high and low temperatures, but also enable the optical fiber filling paste to be used stably for a long time, further ensure that oil separation does not occur, and effectively prevent erosion by water, air, etc.; the combination of the two significantly improves the elasticity and water resistance of the optical fiber filling paste, enhances the adhesion of the optical fiber filling paste, makes it difficult to form gaps between layers, improves the corrosion resistance, oxidation resistance and aging resistance of the present invention, and ensures the signal transmission stability and service life of the sensor optical cable of the present invention.

[0044] Specifically, in the embodiment of the present invention, the medium molecular weight polyisobutylene selected is polyisobutylene B11 produced by BASF; the high activity low molecular weight polyisobutylene is high activity polyisobutylene produced by Fengtong Chemical.

[0045] Preferably, the preparation method of siloxane-modified polyvinyl alcohol comprises the following steps:

[0046] S1. The polyvinyl alcohol was dissolved in deionized water, and then 1 wt% nanocellulose solution was added and stirred at room temperature for 1-2 h to obtain a pretreated polyvinyl alcohol mixture;

[0047] S2. Add the double-terminal carboxyl silicone oil to toluene and stir for 0.5-1h, then add it to the above polyvinyl alcohol mixture, react at 65-85°C for 3-4h under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol at least 3 times, and then place it in a 90-110°C oven to dry for 6-8h to obtain siloxane-modified polyvinyl alcohol.

[0048] Preferably, the ratio of polyvinyl alcohol to nanocellulose solution is 0.08-0.15 g / mL; and the amount of double-terminal carboxyl silicone oil added is 10-18% of the mass of the polyvinyl alcohol.

[0049] The present invention first uses cellulose and polyvinyl alcohol for pretreatment to generate hydrogen bonds, and then uses double-terminal carboxyl silicone oil to modify the pretreated polyvinyl alcohol to obtain siloxane-modified polyvinyl alcohol, which has better compatibility with organic ammonium-modified bentonite, and increases the compatibility of organic ammonium-modified bentonite in base oil. Siloxane-modified polyvinyl alcohol and organic ammonium-modified bentonite cooperate with each other, are added to the optical fiber filling paste, are miscible with the base oil, and thicken the flowing base oil into a viscous and non-flowing semi-solid state, and can maintain a completely dispersed state in the base oil for a long time, so that the base oil molecules are uniformly and stably mixed in the grid composed of the siloxane-modified polyvinyl alcohol molecular chain, and oil separation will not occur; the use of siloxane-modified polyvinyl alcohol not only improves the water resistance and high and low temperature resistance of the optical fiber filling paste, but also improves the comprehensive performance of the present invention such as air tightness and chemical corrosion resistance.

[0050] Specifically, in the embodiment of the present invention, the double-terminated carboxyl silicone oil is selected from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.; the nanocellulose solution is selected from Xianfeng Endurance Materials, model XFJ107, with a diameter of 15-25 nm; and the organic ammonium modified bentonite is selected from Zhejiang Fenghong's QAS-1260 quaternary ammonium salt-18 bentonite.

[0051] Preferably, the antioxidant selected in the embodiment of the present invention is antioxidant 1010, which improves the antioxidant performance of the optical fiber filling paste, prevents or reduces hydrogen evolution of the optical fiber filling paste, and ensures the transmission stability and service life of the sensing optical fiber 1.

[0052] Preferably, the preparation method of the optical fiber filling paste specifically comprises the following steps:

[0053] P1. Add paraffin-based hydrogenated white oil and poly-α-olefin synthetic oil to a reactor and mix, heat to 150-170°C, remove impurities and moisture, and obtain a mixed oil A;

[0054] P2. Add epoxy vinyl silicone oil, 1 / 3 mass fraction of oil separation inhibitor and 1 / 2 mass fraction of polyisobutylene material to the above mixed oil A, stir at 150-180°C for 0.5-1h, cool to 25±5°C, and obtain mixed oil B;

[0055] P3. The siloxane-modified polyvinyl alcohol, the remaining 2 / 3 mass parts of the oil separation inhibitor and the remaining 1 / 2 mass parts of the polyisobutylene material are added to the mixed oil B, stirred at 80-90 ° C, and cooled to 40 ± 5 ° C to obtain a mixture C;

[0056] P4. Add organic ammonium modified bentonite, ferric acetylacetonate and antioxidant to mixture C, stir evenly to obtain optical fiber filling paste.

[0057] Preferably, the type of the sensing optical fiber 1 of the present invention is G652D-high-sensitivity optical fiber; the TPEE sleeve 2 is made of TPEE material with a Poisson's ratio of <0.5, the outer diameter of the TPEE sleeve 2 is 2.0±0.1mm, and the wall thickness is 0.5±0.1mm; the outer diameter of the PBT sleeve 4 is 5.0±0.3mm, and the wall thickness is 0.5±0.1mm; the outer sheath 6 is made of HDPE material, and the outer diameter of the outer sheath 6 is 8.0±0.5mm, and the wall thickness is 1.0±0.1mm. The structure and material settings of the present invention can ensure that the optical fiber attenuation constant of the present invention is low, α1550≤0.185dB / km; the tensile strength of the optical cable is high, and the tensile strength is>400N; the bending performance of the optical cable is good, and it can pass the bending test of 15 times the outer diameter of the optical cable; and it meets the environmental performance requirements, adopts environmentally friendly materials, meets the requirements of energy saving, and is environmentally friendly.

[0058] The present invention also provides a preparation process of a sensor optical cable for detecting vibration, and the process is as follows:

[0059] Step 1, in a straight-up manner, the sensing optical fiber 1 and the TPEE are placed through a mold to obtain a tight-fitting optical fiber;

[0060] Step 2: The tight-fitting optical fiber and the inner layer of water-blocking fiber paste 3 are passed through the mold in a straight manner to extrude the PBT sleeve;

[0061] Step three, put the PBT sleeve and the outer layer of water-blocking fiber paste 5 through the die in a straight manner, and extrude the PE outer sheath 6.

[0062] The optical sensor cable for detecting vibration of the present invention will be described below in conjunction with specific embodiments.

[0063] In Example 1, the inner layer water-blocking fiber paste 3 and the outer layer water-blocking fiber paste 5 are both water-repellent optical fiber filling pastes. The preparation method of the optical fiber filling paste of this embodiment is as follows:

[0064] P1. Weigh each raw material component by mass and set aside;

[0065] P2. 70 parts of paraffin-based hydrogenated white oil were added to the reactor and mixed, and the temperature was raised to 160 ° C, and impurities and water were removed to obtain a mixed oil A;

[0066] P2. 30 parts of epoxy vinyl silicone oil, 1.7 parts of oil separation inhibitor and 3 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1 hour, cooled to 25 ° C, to obtain a mixed oil B;

[0067] P3. 10 parts of siloxane-modified polyvinyl alcohol, 3.3 parts of oil separation inhibitor and 3 parts of polyisobutylene material were added to the mixed oil B, stirred at 80 ° C, cooled to 40 ° C to obtain a mixture C;

[0068] P4. Add 12 parts of organic ammonium modified bentonite, 0.1 parts of ferric acetylacetonate and 0.8 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0069] The polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of 3:1.

[0070] The preparation method of the above-mentioned siloxane-modified polyvinyl alcohol comprises the following steps:

[0071] S1. 15 g of polyvinyl alcohol was dissolved in 125 mL of deionized water, and then 100 mL of 1 wt % nanocellulose solution was added and stirred at room temperature for 2 h to obtain a pretreated polyvinyl alcohol mixture;

[0072] S2. Add 2.5 g of double-terminal carboxyl silicone oil to 50 mL of toluene and stir for 1 hour, then add to the above polyvinyl alcohol mixture, react at 70°C for 4 hours under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol 3 times, and then place it in an oven at 100°C to dry for 8 hours to obtain siloxane-modified polyvinyl alcohol.

[0073] In Example 2, the inner layer water-blocking fiber paste 3 and the outer layer water-blocking fiber paste 5 are both water-repellent optical fiber filling pastes. The preparation method of the optical fiber filling paste of this embodiment is as follows:

[0074] P1. Weigh each raw material component by mass and set aside;

[0075] P2. 70 parts of poly-α-olefin synthetic oil were added to the reactor and mixed, and the temperature was raised to 150 ° C, and impurities and water were removed to obtain a mixed oil A;

[0076] P2. 30 parts of epoxy vinyl silicone oil, 1.7 parts of oil separation inhibitor and 4 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1 hour, cooled to 25 ° C, to obtain a mixed oil B;

[0077] P3. 8 parts of siloxane-modified polyvinyl alcohol, 3.3 parts of oil separation inhibitor and 4 parts of polyisobutylene material were added to the mixed oil B, stirred at 80 ° C, cooled to 40 ° C, to obtain a mixture C;

[0078] P4. Add 15 parts of organic ammonium modified bentonite, 0.3 parts of ferric acetylacetonate and 1.2 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0079] The polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of 5:1.

[0080] The preparation method of the above-mentioned siloxane-modified polyvinyl alcohol comprises the following steps:

[0081] S1. 15 g of polyvinyl alcohol was dissolved in 125 mL of deionized water, and then 180 mL of 1 wt % nanocellulose solution was added and stirred at room temperature for 2 h to obtain a pretreated polyvinyl alcohol mixture;

[0082] S2. Add 1.8 g of double-terminal carboxyl silicone oil to 50 mL of toluene and stir for 1 hour, then add to the above polyvinyl alcohol mixture, react at 70°C for 4 hours under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol 3 times, and then place it in an oven at 100°C to dry for 8 hours to obtain siloxane-modified polyvinyl alcohol.

[0083] In Example 3, the inner layer water-blocking fiber paste 3 and the outer layer water-blocking fiber paste 5 are both water-repellent optical fiber filling pastes. The preparation method of the optical fiber filling paste of this embodiment is as follows:

[0084] P1. Weigh each raw material component by mass and set aside;

[0085] P2. 50 parts of paraffin-based hydrogenated white oil and 40 parts of poly-α-olefin synthetic oil were added to the reactor and mixed, heated to 170 ° C, and impurities and water were removed to obtain a mixed oil A;

[0086] P2. 10 parts of epoxy vinyl silicone oil, 1.0 parts of oil separation inhibitor and 2.5 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1h, cooled to 25 ° C, to obtain a mixed oil B;

[0087] P3. 15 parts of silicone-modified polyvinyl alcohol, 2 parts of oil separation inhibitor and 2.5 parts of polyisobutylene material were added to the mixed oil B, stirred at 80 ° C, cooled to 40 ° C to obtain a mixture C;

[0088] P4. Add 10 parts of organic ammonium modified bentonite, 0.2 parts of ferric acetylacetonate and 1.0 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0089] The polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of 4:1.

[0090] The preparation method of the above-mentioned siloxane-modified polyvinyl alcohol comprises the following steps:

[0091] S1. 15 g of polyvinyl alcohol was dissolved in 125 mL of deionized water, and then 120 mL of 1 wt % nanocellulose solution was added and stirred at room temperature for 2 h to obtain a pretreated polyvinyl alcohol mixture;

[0092] S2. Add 2.1 g of double-terminal carboxyl silicone oil to 50 mL of toluene and stir for 1 hour, then add to the above polyvinyl alcohol mixture, react at 70°C for 4 hours under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol 3 times, and then place it in an oven at 100°C to dry for 8 hours to obtain siloxane-modified polyvinyl alcohol.

[0093] In Example 4, the inner layer water-blocking fiber paste 3 and the outer layer water-blocking fiber paste 5 are both water-repellent optical fiber filling pastes. The preparation method of the optical fiber filling paste of this embodiment is as follows:

[0094] P1. Weigh each raw material component by mass and set aside;

[0095] P2. 50 parts of paraffin-based hydrogenated white oil and 30 parts of poly-α-olefin synthetic oil were added to the reactor and mixed, heated to 170 ° C, and impurities and water were removed to obtain a mixed oil A;

[0096] P2. 20 parts of epoxy vinyl silicone oil, 0.7 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1 hour, cooled to 25 ° C, and obtained mixed oil B;

[0097] P3. 12 parts of siloxane-modified polyvinyl alcohol, 1.3 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil B, stirred at 80 ° C, cooled to 40 ° C, to obtain a mixture C;

[0098] P4. Add 12 parts of organic ammonium modified bentonite, 0.2 parts of ferric acetylacetonate and 0.6 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0099] The raw material components of the polyisobutylene material and the siloxane-modified polyvinyl alcohol are the same as those in Example 3, and specific details are referred to Example 3.

[0100] In Example 5, the inner layer of water-blocking fiber paste 3 is a water-repellent optical fiber filling paste, and the outer layer of water-blocking fiber paste 5 is a water-swellable optical fiber filling paste. The preparation method of the outer layer of water-blocking fiber paste 5 of this Example 5 is:

[0101] P1. Weigh each raw material component by mass and set aside;

[0102] P2. 50 parts of paraffin-based hydrogenated white oil and 30 parts of poly-α-olefin synthetic oil were added to the reactor and mixed, heated to 170 ° C, and impurities and water were removed to obtain a mixed oil A;

[0103] P2. 20 parts of epoxy vinyl silicone oil, 0.7 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1 hour, cooled to 25 ° C, and obtained mixed oil B;

[0104] P3. 15 parts of sodium polyacrylate, 12 parts of siloxane-modified polyvinyl alcohol, 1.3 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil B, stirred at 80 ° C, cooled to 40 ° C, to obtain a mixture C;

[0105] P4. Add 12 parts of organic ammonium modified bentonite, 0.2 parts of ferric acetylacetonate and 0.6 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0106] The raw material components of the polyisobutylene material and the siloxane-modified polyvinyl alcohol are the same as those in Example 3, and specific details are referred to Example 3.

[0107] In Example 6, the inner layer of water-blocking fiber paste 3 is a water-repellent optical fiber filling paste, and the outer layer of water-blocking fiber paste 5 is a water-absorbing and swelling optical fiber filling paste. The preparation method of the outer layer of water-blocking fiber paste 5 of this Example 6 is:

[0108] P1. Weigh each raw material component by mass and set aside;

[0109] P2. 50 parts of paraffin-based hydrogenated white oil and 30 parts of poly-α-olefin synthetic oil were added to the reactor and mixed, heated to 170 ° C, and impurities and water were removed to obtain a mixed oil A;

[0110] P2. 20 parts of epoxy vinyl silicone oil, 0.7 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil A, stirred at 170 ° C for 1 hour, cooled to 25 ° C, and obtained mixed oil B;

[0111] P3. 15 parts of chitosan grafted modified polyacrylamide, 12 parts of siloxane modified polyvinyl alcohol, 1.3 parts of oil separation inhibitor and 2 parts of polyisobutylene material were added to the mixed oil B, stirred at 80°C, and cooled to 40°C to obtain a mixture C;

[0112] P4. Add 12 parts of organic ammonium modified bentonite, 0.2 parts of ferric acetylacetonate and 0.6 parts of antioxidant 1010 to mixture C, stir evenly to obtain optical fiber filling paste.

[0113] The raw material components of the polyisobutylene material and the siloxane-modified polyvinyl alcohol are the same as those in Example 3, and specific details are referred to Example 3.

[0114] Comparative Example 1: The raw materials and preparation method of the optical fiber filling paste in this comparative example 1 are the same as those in Example 4, and specific reference is made to Example 4. The difference is that no siloxane-modified polyvinyl alcohol is added in this comparative example 1, and the amount of organic ammonium-modified bentonite added is 24 parts.

[0115] Comparative Example 2: The raw materials and preparation method of the optical fiber filling paste in this comparative example 2 are the same as those in Example 4, and specific reference is made to Example 4. The difference is that in this comparative example 2, a mixture of double-terminal carboxyl silicone oil and polyvinyl alcohol is used to replace the siloxane-modified polyvinyl alcohol, that is, the mixture is composed of double-terminal carboxyl silicone oil and polyvinyl alcohol in a mass ratio of 7:50.

[0116] Comparative Example 3, the raw materials and preparation method of the optical fiber filling paste in this comparative example 3 are the same as those in Example 4, and specific reference is made to Example 4. The difference is that the preparation method of the siloxane-modified polyvinyl alcohol in this comparative example 3 is as follows: 15g of polyvinyl alcohol is added to 125mL of deionized water to dissolve; 2.1g of double-terminated carboxyl silicone oil is added to 50mL of toluene and stirred for 1h, and then added to the above polyvinyl alcohol solution, reacted at 70°C for 4h under a nitrogen atmosphere, and then diluted acid was added to adjust the pH value to 7, cooled to room temperature, and the product was washed 3 times with anhydrous ethanol, and then placed in an oven at 100°C for 8h to obtain siloxane-modified polyvinyl alcohol.

[0117] Comparative Example 4: The raw materials and preparation method of the optical fiber filling paste in this comparative example 3 are the same as those in Example 4, and specific reference is made to Example 4. The difference is that the polyisobutylene material in this comparative example 3 is medium molecular weight polyisobutylene.

[0118] The optical fiber filling pastes prepared in the above-mentioned Examples 1-4 and Comparative Examples 1-4 were subjected to performance tests, and the test results are shown in Table 1 below.

[0119] Table 1 Performance test results of optical fiber filling paste

[0120]

[0121] It can be seen from the experimental results in Table 1 above that the optical fiber filling paste of the present invention still has a good cone penetration under high and low temperature conditions, has excellent water barrier properties, high and low temperature resistance, oxidation resistance, etc., lower hydrogen evolution degree, oil evolution amount, etc., and has good compatibility with the adjacent layers of the sensor optical cable, ensuring the transmission stability of the optical fiber of the optical cable of the present invention and the sensitivity of detecting vibration.

[0122] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A sensor optical cable for detecting vibrations, comprising a sensor cable core and a protective layer outside the sensor cable core, characterized in that: The sensing cable core is a tight-fitting optical fiber consisting of a sensing optical fiber (1) and a TPEE sleeve (2) wrapped around the sensing optical fiber (1), and the protective layer comprises, from the inside to the outside, an inner layer of water-blocking fiber paste (3), a PBT sleeve (4), an outer layer of water-blocking fiber paste (5), and an outer sheath (6); The inner layer water-blocking fiber paste (3) and the outer layer water-blocking fiber paste (5) are both optical fiber filling pastes, and the optical fiber filling paste is made of the following raw materials in parts by weight: 0-70 parts of paraffin-based hydrogenated white oil, 0-70 parts of poly-α-olefin synthetic oil, 10-30 parts of epoxy vinyl silicone oil, 2-5 parts of oil separation inhibitor, 3-8 parts of polyisobutylene material, 8-15 parts of siloxane-modified polyvinyl alcohol, 5-15 parts of organic ammonium-modified bentonite, 0.1-0.3 parts of ferric acetylacetonate, and 0.5-2.0 parts of antioxidant; The preparation method of the silicone-modified polyvinyl alcohol comprises the following steps: S1. Add polyvinyl alcohol to deionized water to dissolve, then add the nanocellulose solution and stir for 1-2h at room temperature to obtain a pretreated polyvinyl alcohol mixture; The ratio of the polyvinyl alcohol to the nanocellulose solution is 0.08-0.15 g / mL, and the mass concentration of the nanocellulose solution is 1%; S2. Add the double-terminal carboxyl silicone oil to toluene and stir for 0.5-1h, then add it to the above polyvinyl alcohol mixture, react at 65-85°C for 3-4h under a nitrogen atmosphere, then add dilute acid to adjust the pH value to 7, cool to room temperature, wash the product with anhydrous ethanol at least 3 times, and then place it in an oven at 90-110°C to dry for 6-8h to obtain siloxane-modified polyvinyl alcohol; The added amount of the double-terminal carboxyl silicone oil is 10-18% of the mass of the polyvinyl alcohol.

2. The optical sensor cable for detecting vibration according to claim 1, characterized in that: The raw materials of the outer layer water-blocking fiber paste (5) further include 5-20 parts by weight of polymer water-absorbing material.

3. The optical sensor cable for detecting vibration according to claim 2, characterized in that: The polymer water-absorbing material is sodium polyacrylate or chitosan grafted modified polyacrylamide.

4. The optical sensor cable for detecting vibration according to claim 1, characterized in that: The polyisobutylene material is composed of medium molecular weight polyisobutylene and high activity low molecular weight polyisobutylene in a mass ratio of (3-5):

1.

5. The optical sensor cable for detecting vibration according to claim 4, characterized in that: The viscosity average molecular weight of the medium molecular weight polyisobutylene is 40000-55000, the molecular weight of the high activity low molecular weight polyisobutylene is 900-1150, and the α-olefin content is ≥80%.

6. The optical sensor cable for detecting vibration according to claim 1, characterized in that: The preparation method of the optical fiber filling paste specifically comprises the following steps: P1. Add paraffin-based hydrogenated white oil and poly-α-olefin synthetic oil to a reactor and mix, heat to 150-170°C, remove impurities and moisture, and obtain a mixed oil A; P2. Add epoxy vinyl silicone oil, 1 / 3 mass fraction of oil separation inhibitor and 1 / 2 mass fraction of polyisobutylene material to the above mixed oil A, stir at 150-180°C for 0.5-1h, cool to 25±5°C, and obtain mixed oil B; P3. The siloxane-modified polyvinyl alcohol, the remaining 2 / 3 mass parts of the oil separation inhibitor and the remaining 1 / 2 mass parts of the polyisobutylene material are added to the mixed oil B, stirred at 80-90 ° C, and cooled to 40 ± 5 ° C to obtain a mixture C; P4. Add organic ammonium modified bentonite, ferric acetylacetonate and antioxidant to mixture C, stir evenly to obtain optical fiber filling paste.

7. The optical sensor cable for detecting vibration according to claim 1, characterized in that: The TPEE sleeve (2) has an outer diameter of 2.0±0.1 mm and a wall thickness of 0.5±0.1 mm. The TPEE sleeve (2) is made of a TPEE material with a Poisson's ratio of less than 0.

5. The outer diameter of the PBT sleeve (4) is 5.0±0.3 mm, and the wall thickness is 0.5±0.1 mm; The outer diameter of the outer sheath (6) is 8.0±0.5 mm, and the wall thickness is 1.0±0.1 mm. The outer sheath (6) is made of HDPE material.

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