Flexible low-temperature-resistant optical fiber cable and preparation method thereof

Abstract

The invention relates to the field of optical fiber cables, in particular to a flexible low-temperature-resistant optical fiber cable and a preparation method thereof, and is used for solving the problem that an existing optical fiber cable is poor in cold resistance. According to the preparation method, high-density polyethylene and linear low-density polyethylene are used as main raw materials, and the freezing-resistant modifier has good low-temperature toughness, so that the low-temperature brittleness of a cable jacket can be greatly reduced when the freezing-resistant modifier is added into the optical fiber cable, the cable jacket still cannot be embrittled under the low-temperature condition, the optical fiber cable is prevented from being frozen and fractured, and the service life of the cable jacket is prolonged. And the service life of the optical fiber cable is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber cables, and in particular to a flexible low-temperature-resistant optical fiber cable and a preparation method thereof. Background Art

[0002] Optical fiber cable is a communication cable, which is composed of two or more glass or plastic optical fiber cores. To protect the optical fiber core, an optical cable sheath must be set outside the optical fiber core. However, since most cables are working outdoors for a long time, weather changes greatly affect the service life of optical fiber cables. Especially in northern my country, the temperature is low and the time is long in winter. The optical fiber cable is in a cold environment for a long time, which will cause the optical cable sheath material to become brittle and crack. In addition, heavy snow in continuous snowfall weather can easily break the cable, causing great safety hazards. Therefore, improving the cold resistance of the optical cable sheath is the key to the present invention. Therefore, there is an urgent need for a flexible, low-temperature-resistant optical fiber cable and a preparation method thereof to solve the problem of poor cold resistance of existing optical fiber cables. Summary of the invention

[0003] In order to overcome the above technical problems, the object of the present invention is to provide a flexible low-temperature resistant optical fiber cable and a preparation method thereof: by uniformly mixing high-density polyethylene, linear low-density polyethylene, a freeze-resistant modifier, titanium dioxide, a lubricant, an antioxidant and an ultraviolet absorber to obtain a cable material, extruding the cable material onto a cable core through an extruder, cooling and shaping, and forming a cable jacket on the outside of the cable core to obtain a flexible low-temperature resistant optical fiber cable, thereby solving the problem of poor cold resistance of existing optical fiber cables.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a flexible low-temperature-resistant optical fiber cable comprises the following steps: Weigh 65-75 parts of high-density polyethylene, 18-26 parts of linear low-density polyethylene, 2-16 parts of frost resistance modifier, 3-6 parts of titanium dioxide, 3-8 parts of lubricant, 1-3 parts of antioxidant and 1-3 parts of ultraviolet absorber according to weight parts and set aside; High-density polyethylene, linear low-density polyethylene, a freeze-resistant modifier, titanium dioxide, a lubricant, an antioxidant and an ultraviolet absorber are uniformly mixed to obtain a cable material; The cable material is extruded onto the cable core through an extruder, cooled and shaped, and a cable jacket is formed outside the cable core to obtain a flexible, low-temperature resistant optical fiber cable.

[0005] As a further solution of the present invention: the lubricant is one of polyethylene wax and vinyl acetate wax; the antioxidant is one of antioxidant 168 and antioxidant 1076; the ultraviolet absorber is one of ultraviolet absorber UVP-327 and ultraviolet absorber UV-531.

[0006] As a further solution of the present invention: the freeze resistance modifier is prepared by the following steps: Step A1: p-xylene, iodine and dichloromethane are added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and liquid bromine is added dropwise while stirring at a temperature of -5-0°C and a stirring rate of 400-500r / min, and the dropping rate is controlled to be 1-2 drops / s. After the dropwise addition is completed, the temperature is raised to 10-15°C and the stirring reaction is continued for 15-20h, and then potassium hydroxide solution is added and the stirring reaction is continued for 30-50min. After the reaction is completed, the reaction product is allowed to stand at a temperature of -5-0°C for 8-10h, and then vacuum filtered, and the filter cake is washed with distilled water 2-3 times, and then placed in a vacuum drying oven and dried at a temperature of 70-80°C for 2-3h to obtain intermediate 1; The reaction principle is as follows:

[0007] Step A2: Add intermediate 1, benzyltriethylammonium chloride and deionized water to a three-necked flask equipped with a stirrer and a thermometer, add potassium permanganate while stirring at a temperature of 100-105°C and a stirring rate of 400-500r / min, add in 3-5 times, the amount added each time is the same, the interval time is 0.5-1h, continue to stir and react for 8-10h after the addition is completed, filter the reaction product while hot after the reaction is completed, add sodium bisulfite to the filtrate to adjust until the purple color disappears, then adjust the pH to 12-13 with potassium hydroxide solution, then remove the solvent by rotary evaporation, then add to concentrated hydrochloric acid, then vacuum filter, place the filter cake in a vacuum drying oven, and dry it at a temperature of 60-65°C for 3-4h to obtain intermediate 2; The reaction principle is as follows:

[0008] Step A3: Add intermediate 2, sodium hydroxide, copper powder and deionized water to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, stir and react for 20-30 minutes at a temperature of 25-30°C and a stirring rate of 400-500r / min, then heat to reflux while stirring, control the heating rate to 2-3°C / min, and continue stirring to react for 10-15 hours. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, adjust the filtrate to pH 3-4 with hydrochloric acid solution, precipitate, and then vacuum filter, wash the filter cake with distilled water 2-3 times, and then place it in a vacuum drying oven and dry it at a temperature of 60-70°C for 4-5 hours to obtain intermediate 3; The reaction principle is as follows:

[0009] Step A4: Add biphenyl, anhydrous aluminum chloride and dichloromethane to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, add liquid bromine dropwise while stirring at a temperature of -5-0°C and a stirring rate of 400-500r / min, and control the dropping rate to 1-2 drops / s. After the addition is completed, the temperature is raised to 25-30°C and the stirring reaction is continued for 6-8h. After the reaction is completed, the reaction product is poured into ethyl acetate, and then washed with sodium hydroxide solution 2-3 times, and then allowed to stand for stratification. The organic phase is dried over anhydrous magnesium sulfate, and then vacuum filtered, and the filtrate is rotary evaporated to remove the solvent to obtain intermediate 4; The reaction principle is as follows:

[0010] Step A5: Add intermediate 3, intermediate 4, anhydrous potassium carbonate and N,N-dimethylformamide to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stir the mixture for 30-40 min at a temperature of 25-30° C. and a stirring rate of 400-500 r / min, then heat the mixture to reflux while stirring, control the heating rate to 2-3° C. / min, and continue stirring the mixture for 20-30 h. After the reaction is completed, cool the reaction product to room temperature, and then vacuum filter it, and rotary evaporate the filtrate to remove the solvent to obtain intermediate 5; The reaction principle is as follows:

[0011] Step A6: Add intermediate 5, n-octanol, p-toluenesulfonic acid and chloroform to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 30-40 minutes at a temperature of 25-30°C and a stirring rate of 400-500r / min, then raise the temperature to 135-140°C and continue stirring and reacting for 5-6 hours. After the reaction is completed, the reaction product is cooled to room temperature, washed with distilled water 2-3 times, and then allowed to stand for stratification. The organic phase is rotary evaporated to remove the solvent, and then recrystallized with n-hexane to obtain a freeze-resistant modifier.

[0012] The reaction principle is as follows:

[0013] As a further scheme of the present invention: the dosage ratio of the p-xylene, iodine, dichloromethane, liquid bromine and potassium hydroxide solution in step A1 is 0.1 mol: 0.25-0.3 g: 70-80 mL: 0.1 mol: 70-80 mL, and the mass fraction of the potassium hydroxide solution is 25-30%.

[0014] As a further scheme of the present invention: the usage ratio of the intermediate 1, benzyltriethylammonium chloride, deionized water and potassium permanganate in step A2 is 0.1 mol: 0.2-0.3 g: 180-200 mL: 40-45 g, the mass fraction of the potassium hydroxide solution is 25-30%, and the mass fraction of the concentrated hydrochloric acid is 36-38%.

[0015] As a further solution of the present invention: the usage ratio of the intermediate 2, sodium hydroxide, copper powder and deionized water in step A3 is 0.1 mol: 2.5-3.5 g: 0.3-0.4 g: 50-60 mL, and the mass fraction of the hydrochloric acid solution is 25-30%.

[0016] As a further scheme of the present invention: the usage ratio of the biphenyl, anhydrous aluminum chloride, dichloromethane and liquid bromine in step A4 is 0.1 mol: 0.0015-0.003 mol: 50-60 mL: 0.22-0.25 mol, and the mass fraction of the sodium hydroxide solution is 15-20%.

[0017] As a further scheme of the present invention: the usage ratio of the intermediate 3, intermediate 4, anhydrous potassium carbonate and N,N-dimethylformamide in step A5 is 0.2 mol: 0.1 mol: 0.22-0.25 mol: 150-200 mL.

[0018] As a further scheme of the present invention: the usage ratio of the intermediate 5, n-octanol, p-toluenesulfonic acid and chloroform in step A6 is 0.1 mol: 0.44-0.5 mol: 2.4-3.6 g: 80-100 mL.

[0019] As a further solution of the present invention: a flexible low-temperature resistant optical fiber cable comprises a cable core and a cable jacket wrapped around the cable core, wherein the flexible low-temperature resistant optical fiber cable is prepared according to the preparation method of the flexible low-temperature resistant optical fiber cable.

[0020] Beneficial effects of the present invention: The present invention discloses a flexible low-temperature-resistant optical fiber cable and a preparation method thereof. The cable material is obtained by uniformly mixing high-density polyethylene, linear low-density polyethylene, a freezing-resistant modifier, titanium dioxide, a lubricant, an antioxidant and an ultraviolet absorber. The cable material is extruded on a cable core through an extruder, cooled and shaped, and a cable jacket is formed outside the cable core to obtain a flexible low-temperature-resistant optical fiber cable. In the preparation method, high-density polyethylene and linear low-density polyethylene are used as main raw materials, and a freezing-resistant modifier is added thereto to give the high-density polyethylene and the low-temperature-resistant optical fiber cable good flexibility and low-temperature resistance, so that the prepared optical fiber cable will not become brittle under low-temperature conditions, thereby preventing the optical fiber cable from being broken due to freezing. In the process of preparing a flexible low-temperature resistant optical fiber cable, a freeze-resistant modifier is first prepared. First, p-xylene is brominated with liquid bromine to introduce bromine atoms to obtain intermediate 1. Then, the methyl group on intermediate 1 is oxidized to a carboxyl group using potassium permanganate to obtain intermediate 2. Then, the bromine atom on intermediate 2 is converted into a hydroxyl group to obtain intermediate 3 containing 2 carboxyl groups and 1 hydroxyl group. Then, biphenyl is brominated with liquid bromine to introduce bromine atoms to obtain intermediate 4. Then, the bromine atom on intermediate 4 and the hydroxyl group on intermediate 3 undergo a nucleophilic substitution reaction to obtain intermediate 5, forming a skeleton containing 4 carboxyl groups. Then, The carboxyl group on the intermediate 5 undergoes an esterification reaction with n-octanol, thereby connecting four long carbon chains on the skeleton to obtain a freeze-resistant modifier; the freeze-resistant modifier has a large number of benzene rings as the skeleton, which gives the freeze-resistant modifier good support, a highly branched structure, is difficult to crystallize, has a large molecular free volume, and contains a large amount of unoccupied space in the three-dimensional network. The connected long carbon chains give it good flexibility, and it still has good mobility in ultra-low temperature environments, giving it good low-temperature toughness. Therefore, the freeze-resistant modifier is added to the optical fiber cable to greatly reduce the low-temperature brittleness of the cable jacket, and will not be damaged by freezing, thereby increasing the service life of the optical fiber cable. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0022] Embodiment 1: This embodiment is a method for preparing a freeze-resistant modifier, comprising the following steps: Step A1: 0.1 mol of p-xylene, 0.25 g of iodine and 70 mL of dichloromethane are added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and 0.1 mol of liquid bromine is added dropwise while stirring at a temperature of -5°C and a stirring rate of 400 r / min, and the dropping rate is controlled to be 1 drop / s. After the dropwise addition is completed, the temperature is raised to 10°C and the stirring reaction is continued for 15 hours, and then 70 mL of a 25% potassium hydroxide solution is added and the stirring reaction is continued for 30 minutes. After the reaction is completed, the reaction product is allowed to stand at a temperature of -5°C for 8 hours, and then vacuum filtered, the filter cake is washed twice with distilled water, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 2 hours to obtain intermediate 1; Step A2: 0.1 mol of intermediate 1, 0.2 g of benzyltriethylammonium chloride and 180 mL of deionized water are added to a three-necked flask equipped with a stirrer and a thermometer, and 40 g of potassium permanganate is added while stirring at a temperature of 100° C. and a stirring rate of 400 r / min. The mixture is added in three times, with the same amount added each time and an interval of 0.5 h. After the addition is completed, the reaction is continued to stir for 8 h. After the reaction is completed, the reaction product is filtered while hot, sodium bisulfite is added to the filtrate to adjust until the purple color disappears, and then the pH is adjusted to 12 with a potassium hydroxide solution with a mass fraction of 25%, and then the solvent is removed by rotary evaporation, and then added to a concentrated hydrochloric acid with a mass fraction of 36%, and then vacuum filtered. The filter cake is placed in a vacuum drying oven and dried at a temperature of 60° C. for 3 h to obtain intermediate 2; Step A3: 0.1 mol of intermediate 2, 2.5 g of sodium hydroxide, 0.3 g of copper powder and 50 mL of deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 25°C and a stirring rate of 400 r / min for 20 min, then heated to reflux while stirring, and the heating rate was controlled to be 2°C / min, and then the stirring reaction was continued for 10 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered, and the filtrate was adjusted to pH 3 with a 25% hydrochloric acid solution to precipitate, and then vacuum filtered, and the filter cake was washed twice with distilled water, and then placed in a vacuum drying oven and dried at a temperature of 60°C for 4 h to obtain intermediate 3; Step A4: 0.1 mol of biphenyl, 0.0015 mol of anhydrous aluminum chloride and 50 mL of dichloromethane were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and 0.22 mol of liquid bromine was added dropwise while stirring at a temperature of -5°C and a stirring rate of 400 r / min. The dropping rate was controlled to be 1 drop / s. After the addition was completed, the temperature was raised to 25°C and the stirring reaction was continued for 6 hours. After the reaction was completed, the reaction product was poured into ethyl acetate, and then washed twice with a sodium hydroxide solution with a mass fraction of 15%, and then allowed to stand for stratification. The organic phase was dried over anhydrous magnesium sulfate, and then vacuum filtered. The filtrate was rotary evaporated to remove the solvent to obtain intermediate 4; Step A5: 0.2 mol of intermediate 3, 0.1 mol of intermediate 4, 0.22 mol of anhydrous potassium carbonate and 150 mL of N,N-dimethylformamide were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 25°C and a stirring rate of 400 r / min for 30 min, then heated to reflux while stirring, and the heating rate was controlled to 2°C / min, and then the stirring reaction was continued for 20 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain intermediate 5; Step A6: Add 0.1 mol of intermediate 5, 0.44 mol of n-octanol, 2.4 g of p-toluenesulfonic acid and 80 mL of chloroform into a three-necked flask equipped with a stirrer and a thermometer, and stir the reaction for 30 min at a temperature of 25°C and a stirring rate of 400 r / min. Then, raise the temperature to 135°C and continue stirring the reaction for 5 h. After the reaction, cool the reaction product to room temperature, wash it twice with distilled water, and then let it stand to separate the layers. Rotate the organic phase to remove the solvent, and then recrystallize it with n-hexane to obtain a freeze-resistant modifier.

[0023] Embodiment 2: This embodiment is a method for preparing a freeze-resistant modifier, comprising the following steps: Step A1: 0.1 mol of p-xylene, 0.3 g of iodine and 80 mL of dichloromethane are added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and 0.1 mol of liquid bromine is added dropwise while stirring at a temperature of 0°C and a stirring rate of 500 r / min, and the dropping rate is controlled to be 2 drops / s. After the dropwise addition is completed, the temperature is raised to 15°C and the stirring reaction is continued for 20 hours, and then 80 mL of a 30% potassium hydroxide solution is added and the stirring reaction is continued for 50 minutes. After the reaction is completed, the reaction product is allowed to stand at a temperature of 0°C for 10 hours, and then vacuum filtered, the filter cake is washed with distilled water 3 times, and then placed in a vacuum drying oven and dried at a temperature of 80°C for 3 hours to obtain intermediate 1; Step A2: 0.1 mol of intermediate 1, 0.3 g of benzyltriethylammonium chloride and 200 mL of deionized water are added to a three-necked flask equipped with a stirrer and a thermometer, and 45 g of potassium permanganate is added while stirring at a temperature of 105° C. and a stirring rate of 500 r / min. The mixture is added in 5 times, each time in the same amount, with an interval of 1 h. After the addition is completed, the reaction is continued to be stirred for 10 h. After the reaction is completed, the reaction product is filtered while hot, and sodium bisulfite is added to the filtrate to adjust until the purple color disappears, and then the pH is adjusted to 13 with a potassium hydroxide solution with a mass fraction of 30%, and then the solvent is removed by rotary evaporation, and then added to a concentrated hydrochloric acid with a mass fraction of 38%, and then vacuum filtered. The filter cake is placed in a vacuum drying oven and dried at a temperature of 65° C. for 4 h to obtain intermediate 2; Step A3: 0.1 mol of intermediate 2, 3.5 g of sodium hydroxide, 0.4 g of copper powder and 60 mL of deionized water were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30°C and a stirring rate of 500 r / min for 30 min, then heated to reflux while stirring, and the heating rate was controlled to be 3°C / min, and then the stirring reaction was continued for 15 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered, and the filtrate was adjusted to pH 4 with a mass fraction of 30% hydrochloric acid solution to precipitate, and then vacuum filtered, and the filter cake was washed with distilled water 3 times, and then placed in a vacuum drying oven and dried at a temperature of 70°C for 5 h to obtain intermediate 3; Step A4: 0.1 mol of biphenyl, 0.003 mol of anhydrous aluminum chloride and 60 mL of dichloromethane were added to a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, and 0.25 mol of liquid bromine was added dropwise while stirring at a temperature of 0°C and a stirring rate of 500 r / min. The dropping rate was controlled to be 2 drops / s. After the addition was completed, the temperature was raised to 30°C and the stirring reaction was continued for 8 hours. After the reaction was completed, the reaction product was poured into ethyl acetate, and then washed with a sodium hydroxide solution with a mass fraction of 20% for 3 times, and then allowed to stand for stratification. The organic phase was dried over anhydrous magnesium sulfate, and then vacuum filtered. The filtrate was rotary evaporated to remove the solvent to obtain intermediate 4; Step A5: 0.2 mol of intermediate 3, 0.1 mol of intermediate 4, 0.25 mol of anhydrous potassium carbonate and 200 mL of N,N-dimethylformamide were added to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, and stirred for reaction at a temperature of 30°C and a stirring rate of 500 r / min for 40 min, then heated to reflux while stirring, and the heating rate was controlled to 3°C / min, and then the stirring reaction was continued for 30 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered, and the filtrate was rotary evaporated to remove the solvent to obtain intermediate 5; Step A6: Add 0.1 mol of intermediate 5, 0.5 mol of n-octanol, 3.6 g of p-toluenesulfonic acid and 100 mL of chloroform into a three-necked flask equipped with a stirrer and a thermometer, and stir the reaction for 40 min at a temperature of 30°C and a stirring rate of 500 r / min. Then, raise the temperature to 140°C and continue stirring the reaction for 6 h. After the reaction, cool the reaction product to room temperature, wash it with distilled water three times, let it stand to separate, and rotary evaporate the organic phase to remove the solvent. Then, recrystallize it with n-hexane to obtain a freeze-resistant modifier.

[0024] Embodiment 3: This embodiment is a method for preparing a flexible low-temperature resistant optical fiber cable, comprising the following steps: Step 1: prepare a freeze-resistant modifier according to the method in Example 1 and set aside; Step 2: Weigh 65 parts of high-density polyethylene, 18 parts of linear low-density polyethylene, 2 parts of frost resistance modifier, 3 parts of titanium dioxide, 3 parts of lubricant, 1 part of antioxidant and 1 part of ultraviolet absorber according to weight parts, and set aside; the lubricant is polyethylene wax; the antioxidant is antioxidant 168; the ultraviolet absorber is ultraviolet absorber UVP-327; Step 3: Evenly mix high-density polyethylene, linear low-density polyethylene, antifreeze modifier, titanium dioxide, lubricant, antioxidant and ultraviolet absorber to obtain cable material; Step 4: Extruding the cable material onto the cable core through an extruder, cooling and shaping, forming a cable jacket on the outside of the cable core, and obtaining a flexible, low-temperature-resistant optical fiber cable.

[0025] Embodiment 4: This embodiment is a method for preparing a flexible low-temperature resistant optical fiber cable, comprising the following steps: Step 1: prepare a freeze-resistant modifier according to the method in Example 2 and set aside; Step 2: Weigh 75 parts of high-density polyethylene, 26 parts of linear low-density polyethylene, 16 parts of frost resistance modifier, 6 parts of titanium dioxide, 8 parts of lubricant, 3 parts of antioxidant and 3 parts of ultraviolet absorber according to weight parts, and set aside; the lubricant is vinyl acetate wax; the antioxidant is antioxidant 1076; the ultraviolet absorber is ultraviolet absorber UV-531; Step 3: Evenly mix high-density polyethylene, linear low-density polyethylene, antifreeze modifier, titanium dioxide, lubricant, antioxidant and ultraviolet absorber to obtain cable material; Step 4: Extruding the cable material onto the cable core through an extruder, cooling and shaping, forming a cable jacket on the outside of the cable core, and obtaining a flexible, low-temperature-resistant optical fiber cable.

[0026] Comparative Example 1: The difference between this comparative example and Example 4 is that no freezing resistance modifier is added.

[0027] Comparative Example 2: The difference between this comparative example and Example 4 is that di(2-ethylhexyl)phthalate is added instead of the antifreeze modifier.

[0028] The cable materials of Examples 3-4 and Comparative Examples 1-2 were directly extruded into test samples, and then performance tests were performed. The test results are shown in the following table: sample Example 3 Example 4 Comparative Example 1 Comparative Example 2 Tensile strength at 0℃, MPa 85.9 88.7 79.8 82.2 Elongation at break at 40℃ 328% 340% 252% 311% Brittle temperature, °C -69 -74 -48 -62 Referring to the data in the above table, by comparing Examples 3-4 and Comparative Examples 1-2, it can be seen that the addition of di(2-ethylhexyl) phthalate and frost-resistant modifier can significantly improve the mechanical properties and low-temperature resistance of the cable jacket, among which the frost-resistant modifier has a better improvement effect.

[0029] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0030] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A method for preparing a flexible low-temperature resistant optical fiber cable, characterized in that: The following steps are involved: Weigh 65-75 parts of high-density polyethylene, 18-26 parts of linear low-density polyethylene, 2-16 parts of frost resistance modifier, 3-6 parts of titanium dioxide, 3-8 parts of lubricant, 1-3 parts of antioxidant and 1-3 parts of ultraviolet absorber according to weight parts and set aside; High-density polyethylene, linear low-density polyethylene, a freeze-resistant modifier, titanium dioxide, a lubricant, an antioxidant and an ultraviolet absorber are uniformly mixed to obtain a cable material; The cable material is extruded onto the cable core through an extruder, cooled and shaped, and a cable jacket is formed outside the cable core to obtain a flexible, low-temperature resistant optical fiber cable.

2. The method for preparing a flexible low-temperature resistant optical fiber cable according to claim 1, characterized in that: The lubricant is one of polyethylene wax and vinyl acetate wax; the antioxidant is one of antioxidant 168 and antioxidant 1076; the ultraviolet absorber is one of ultraviolet absorber UVP-327 and ultraviolet absorber UV-531.

3. The method for preparing a flexible low-temperature resistant optical fiber cable according to claim 1, characterized in that: The freeze-resistant modifier is prepared by the following steps: Step A1: p-xylene, iodine and dichloromethane are added to a three-necked flask, and liquid bromine is added dropwise while stirring. After the addition is completed, stirring is continued for reaction, and then potassium hydroxide solution is added and stirring is continued for reaction. After the reaction is completed, the reaction product is allowed to stand, and then vacuum filtered, and the filter cake is washed and dried to obtain intermediate 1; Step A2: Add intermediate 1, benzyltriethylammonium chloride and deionized water into a three-necked flask, add potassium permanganate while stirring, continue stirring to react after the addition is complete, filter the reaction product while hot after the reaction is complete, add sodium bisulfite to the filtrate, adjust the pH, remove the solvent by rotary evaporation, add to concentrated hydrochloric acid, and then vacuum filter, and dry the filter cake to obtain intermediate 2; Step A3: Add intermediate 2, sodium hydroxide, copper powder and deionized water into a three-necked flask and stir to react. After the reaction, cool the reaction product to room temperature, then vacuum filter, adjust the pH of the filtrate, precipitate, then vacuum filter, wash and dry the filter cake to obtain intermediate 3; Step A4: Add biphenyl, anhydrous aluminum chloride and dichloromethane into a three-necked flask, add liquid bromine dropwise while stirring, continue stirring to react after the addition is complete, pour the reaction product into ethyl acetate, wash, let stand to separate, dry the organic phase, vacuum filter, and rotary evaporate the filtrate to obtain intermediate 4; Step A5: Add intermediate 3, intermediate 4, anhydrous potassium carbonate and N,N-dimethylformamide into a three-necked flask and stir to react. After the reaction is completed, cool the reaction product to room temperature, then vacuum filter, and rotary evaporate the filtrate to obtain intermediate 5; Step A6: Add intermediate 5, n-octanol, p-toluenesulfonic acid and chloroform into a three-necked flask and stir to react. After the reaction is completed, cool the reaction product to room temperature, wash it, let it stand to separate the layers, rotary evaporate the organic phase, and then recrystallize it to obtain a freeze-resistant modifier.

4. The method for preparing a flexible low-temperature-resistant optical fiber cable according to claim 3, characterized in that: The dosage ratio of the p-xylene, iodine, dichloromethane, liquid bromine and potassium hydroxide solution in step A1 is 0.1 mol: 0.25-0.3 g: 70-80 mL: 0.1 mol: 70-80 mL, and the mass fraction of the potassium hydroxide solution is 25-30%.

5. The method for preparing a flexible low-temperature-resistant optical fiber cable according to claim 3, characterized in that: The usage ratio of the intermediate 1, benzyltriethylammonium chloride, deionized water and potassium permanganate in step A2 is 0.1 mol: 0.2-0.3 g: 180-200 mL: 40-45 g, and the mass fraction of the concentrated hydrochloric acid is 36-38%.

6. The method for preparing a flexible low-temperature-resistant optical fiber cable according to claim 3, characterized in that: The usage ratio of the intermediate 2, sodium hydroxide, copper powder and deionized water in step A3 is 0.1 mol: 2.5-3.5 g: 0.3-0.4 g: 50-60 mL.

7. The method for preparing a flexible low-temperature resistant optical fiber cable according to claim 3, characterized in that: The usage ratio of the biphenyl, anhydrous aluminum chloride, dichloromethane and liquid bromine in step A4 is 0.1 mol: 0.0015-0.003 mol: 50-60 mL: 0.22-0.25 mol.

8. The method for preparing a flexible low-temperature-resistant optical fiber cable according to claim 3, characterized in that: The usage ratio of the intermediate 3, intermediate 4, anhydrous potassium carbonate and N,N-dimethylformamide in step A5 is 0.2 mol: 0.1 mol: 0.22-0.25 mol: 150-200 mL.

9. The method for preparing a flexible low-temperature-resistant optical fiber cable according to claim 3, characterized in that: The usage ratio of the intermediate 5, n-octanol, p-toluenesulfonic acid and chloroform in step A6 is 0.1 mol: 0.44-0.5 mol: 2.4-3.6 g: 80-100 mL.

10. A flexible low-temperature resistant optical fiber cable, characterized in that: The flexible low temperature resistant optical fiber cable The flexible low-temperature resistant optical fiber cable is prepared according to the preparation method of any one of claims 1 to 9, wherein the flexible low-temperature resistant optical fiber cable comprises a cable core and a cable jacket wrapped around the cable core.

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