CN115394479A - A low noise flexible cable - Google Patents

Abstract

The invention discloses a low-noise flexible cable, which belongs to the technical field of electric cables, and comprises a conductor, an insulating layer, a braided shielding layer and a sheath layer sequentially arranged from the inside to the outside, the conductor is twisted with copper wires, and the insulating layer Coated on the outer wall of the conductor by winding and sintering, the surface of the insulating layer is coated with semi-conductive adhesive, the braided shielding layer is wrapped on the outside of the insulating layer and bonded to the outer wall of the insulating layer through semi-conductive adhesive, and the sheath layer is wrapped on the outside of the braided shielding layer . The present invention adopts polytetrafluoroethylene film as insulating layer, adopts semi-insulating polysilicon material as semi-conductive adhesive, forms semi-insulating polysilicon film after curing, can realize noise reduction effect; by adding magnesium hydroxide and Flame retardant, which endows the sheath material with a stable and long-lasting flame retardant effect; so that the obtained cable can meet the requirements of low noise and fire resistance at the same time, and has a wide application prospect.

Description

A low noise flexible cable

technical field

The invention belongs to the technical field of cables, and in particular relates to a low-noise flexible cable.

Background technique

The impact on the cable comes from the outside and inside of the cable. The disturbance from the outside of the cable is called interference, and the disturbance from the inside of the cable due to physical reasons such as material and structure is called noise. The metal shielding layer is usually used to suppress the external interference of the cable, and the main cause of noise is that when the cable is subjected to external forces (bending, vibration, etc.), the relative displacement between the internal insulating layer and the inner and outer conductors of the insulating layer causes friction.

Low-noise cables are cables whose pulse signals generated by the cable itself are less than 5mV under the action of external factors such as bending, vibration, shock, and temperature changes. Low noise cables are mainly used for the measurement of tiny signals. When the 5G base station is running, there are external factors such as bending, vibration, temperature and frequency changes, which make low-noise cables have a wide application prospect in the construction of 5G base stations. At the same time, the miniaturization and dense coverage of 5G base stations are a major trend. The cables used in the core area of the computer room, some public places, and commercial areas must consider the safety performance of low-smoke, halogen-free, flame-retardant, and fire-proof. The demand for halogen flame-retardant and fire-resistant low-noise cables has broad prospects.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a low-noise flexible cable.

The present invention covers the outer wall of the conductor by adopting high-temperature-resistant polytetrafluoroethylene film and wrapping sintering process to form an insulating layer. After wrapping and sintering, the polytetrafluoroethylene film can form a tight package with the conductor, so that the It is not easy to produce relative movement and separation, thereby reducing cable noise and making the cable more flexible; by using semi-insulating polysilicon material as the semi-conductive adhesive, it will form a semi-insulating polysilicon film after curing, which is a high-temperature resistant film with semi-conductive properties. A semi-conductive layer is formed between the shielding layer and the insulating interface, which can reduce noise;

In the present invention, magnesium hydroxide and flame retardant are added to the outer sheath material at the same time. The flame retardant is a highly efficient and multi-phase flame retardant component, and the material can obtain excellent flame retardant and fireproof effects with a small amount of addition; in addition, the flame retardant The flame retardant molecule also contains terminal C=C, which can participate in the copolymerization process during the melting and mixing process with the matrix material, improving the interaction force between the flame retardant and the matrix, thereby improving the stability of the flame retardant and improving The migration and exudation resistance of the flame retardant endows the sheath material with a stable and long-lasting flame-retardant effect; so that the obtained cable can meet the requirements of low noise and fire resistance at the same time, and has a wide range of application prospects.

The purpose of the present invention can be achieved through the following technical solutions:

A low-noise flexible cable, comprising a conductor, an insulating layer, a braided shielding layer and a sheath layer arranged sequentially from inside to outside;

The conductor is twisted with copper wires, the insulating layer is coated on the outer wall of the conductor by wrapping and sintering, the surface of the insulating layer is coated with semi-conductive glue, the braided shielding layer is wrapped on the outside of the insulating layer and is connected to the outer wall of the insulating layer by the semi-conductive glue Snug, the jacket wraps over the braided shield.

Further, the insulating layer is made of high-temperature-resistant polytetrafluoroethylene (PTFE) film, and is covered on the outer wall of the conductor by wrapping and sintering process. After wrapping and sintering, the PTFE film can form a tight package with the conductor, so that the two It is not easy to produce relative movement and separation between them, thereby reducing cable noise and making the cable more flexible.

Further, the semi-conductive adhesive adopts semi-insulating polysilicon material, which forms a semi-insulating polysilicon film after curing, which belongs to a high-temperature-resistant film with semi-conductive properties, and forms a semi-conductive layer between the braided shielding layer and the insulating interface, which can reduce noise. .

Further, the sheath layer is made of rubber material, and the rubber material includes the following raw materials in parts by weight: 100 parts of polyperfluoroethylene propylene resin, 35-45 parts of ABS resin, 30-40 parts of mica powder, fumed white 15-19 parts of carbon black, 20-30 parts of magnesium hydroxide, 2-3 parts of flame retardant, 1-2 parts of vulcanizing agent, 3-5 parts of heat stabilizer;

Polyfluoroethylene propylene resin can not only be continuously extruded into thin films in small sizes, but also has good wear resistance, flexibility, and high temperature resistance of 200 °C; acrylonitrile-butadiene-styrene copolymer (ABS), is A thermoplastic polymer material with high strength, good toughness and easy processing.

Further, the flame retardant is prepared through the following steps:

S1. Add cyanuric chloride and tetrahydrofuran into a four-necked flask with a mechanical stirring device, stir to dissolve and maintain the temperature of the system at 25°C, dissolve N-methylacrylamine in an appropriate amount of tetrahydrofuran, and gradually dissolve under stirring Add it dropwise into a four-neck flask. After all the addition is complete, raise the temperature of the reaction solution to 50°C, and continue the reaction at this temperature for 48h (during the reaction, use a NaOH solution with a concentration of 0.1mol/L to maintain the pH value above 10) , after the reaction is completed, most of the THF solvent is removed by rotary evaporation, and then extracted 2-3 times with toluene, the organic phase is washed 3-4 times with saturated NaCl aqueous solution, dried with anhydrous sodium sulfate, filtered with suction, and concentrated under reduced pressure to obtain Intermediate 1; the ratio of the amount of cyanuric chloride, tetrahydrofuran, and N-methacrylamine is 0.1mol:150mL:0.33mol;

Cyanuric chloride reacts chemically with N-methylacrylamine to obtain intermediate 1, and the specific reaction process is as follows:

S2. Add mercaptoethylamine and methanol aqueous solution (the volume ratio of methanol to distilled water is 10:1) into a four-necked flask with a stirring device, stir to dissolve and maintain the temperature of the system at 70°C, and intermediate 1 and AIBN (Azobisisobutyronitrile) was dissolved in an appropriate amount of methanol, and was added dropwise into a four-necked flask under stirring, and reacted at 70°C for 4 hours. After the reaction, cooled to room temperature, filtered, and the filter cake was washed with methanol and Wash with deionized water for 3-4 times, and dry in vacuum to obtain intermediate 2; the ratio of the amount of mercaptoethylamine, aqueous methanol, intermediate 1, and AIBN is 0.021mol:110mL:2.88g:0.22g;

Under the action of AIBN, the C=C on the intermediate 1 molecule and the thiol on the mercaptoethylamine molecule undergo a mercapto-ene click reaction, and the intermediate 2 is prepared by controlling the molar ratio of the two to be close to 1:2. The reaction process As follows:

S3. Under the protection of N ₂ , add p-carboxyphenylphosphonic acid, intermediate 2, and triethylamine to a dichloromethane solution in which DIC (N,N-diisopropylcarbodiimide) is dissolved, and Stir the reaction at room temperature and under the protection of _N2 for 3h. After the reaction is over, the solvent dichloromethane is distilled off under reduced pressure, and n-hexane is added for recrystallization, filtered, and vacuum-dried to obtain a flame retardant; p-carboxyphenylphosphonic acid, intermediate 2. The ratio of the amount of triethylamine, DIC and dichloromethane is 0.02mol:4.43g:2.02g:1.26g:150mL;

Under the action of DIC and triethylamine, the -COOH on the p-carboxyphenylphosphonic acid molecule reacts with _-NH2 on the intermediate 2 molecule to generate a flame retardant. The reaction process is as follows:

The obtained flame retardant molecules contain nitrogen-containing heterocycles, benzene rings, sulfur-containing groups and phosphoric acid groups. The nitrogen-containing heterocycles and benzene rings can form an expanded carbon layer in case of fire or high temperature, and the phosphoric acid groups can Condensed phase and gas phase flame retardant, sulfur-containing groups can enhance the flame retardant effect of phosphorus and nitrogen, and play an excellent flame retardant effect in the condensed phase. Therefore, the obtained flame retardant is a highly efficient, multi-phase flame retardant component. A small amount of addition can make the material obtain excellent flame retardant and fireproof effects; in addition, the flame retardant molecule also contains terminal C=C, which can participate in the copolymerization process during the melting and mixing process with the matrix material to improve the flame retardant The interaction force between the agent and the matrix, thereby improving the stability of the flame retardant, improving the migration resistance and exudation resistance of the flame retardant, and endowing the sheath material with a stable and lasting flame retardant effect.

Beneficial effects of the present invention:

The present invention covers the outer wall of the conductor by adopting high-temperature-resistant polytetrafluoroethylene film and wrapping sintering process to form an insulating layer. After wrapping and sintering, the polytetrafluoroethylene film can form a tight package with the conductor, so that the It is not easy to produce relative movement and separation, thereby reducing cable noise and making the cable more flexible; by using semi-insulating polysilicon material as the semi-conductive adhesive, it will form a semi-insulating polysilicon film after curing, which is a high-temperature resistant film with semi-conductive properties. A semi-conductive layer is formed between the shielding layer and the insulating interface, which can reduce noise;

In the present invention, magnesium hydroxide and flame retardant are added to the outer sheath material at the same time. The flame retardant is a highly efficient and multi-phase flame retardant component, and the material can obtain excellent flame retardant and fireproof effects with a small amount of addition; in addition, the flame retardant The flame retardant molecule also contains terminal C=C, which can participate in the copolymerization process during the melting and mixing process with the matrix material, improving the interaction force between the flame retardant and the matrix, thereby improving the stability of the flame retardant and improving The migration and exudation resistance of the flame retardant endows the sheath material with a stable and long-lasting flame-retardant effect; so that the obtained cable can meet the requirements of low noise and fire resistance at the same time, and has a wide range of application prospects.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

Preparation of flame retardant:

S1. Add 0.1mol cyanuric chloride and 150mL tetrahydrofuran into a four-necked flask with a mechanical stirring device, stir to dissolve and maintain the temperature of the system at 25°C, and dissolve 0.33mol of N-methylacrylamine in an appropriate amount of tetrahydrofuran , and added dropwise in the four-necked flask under stirring, after all the dropwise addition was completed, the reaction solution was warmed up to 50°C, and continued to react at this temperature for 48h (in the reaction process, the NaOH solution with a concentration of 0.1mol/L was used to maintain pH value above 10), after the reaction, most of the tetrahydrofuran solvent was removed by rotary evaporation, and then extracted twice with toluene, the organic phase was washed three times with saturated NaCl aqueous solution, dried with anhydrous sodium sulfate, filtered with suction, and concentrated under reduced pressure , to obtain intermediate 1;

S2. Add 0.021mol mercaptoethylamine and 110mL methanol aqueous solution (the volume ratio of methanol to distilled water is 10:1) into a four-necked flask with a stirring device, stir to dissolve and maintain the temperature of the system at 70°C. 2.88g Intermediate 1 and 0.22 g of AIBN (azobisisobutyronitrile) were dissolved in an appropriate amount of methanol, and were added dropwise into a four-neck flask under stirring, and reacted at 70°C for 4 hours. After the reaction was completed, cooled to room temperature, Filtration, the filter cake was washed three times with methanol and deionized water, and dried in vacuum to obtain intermediate 2;

S3, under the protection of N ₂ , add 0.02mol p-carboxyphenylphosphonic acid, 4.43g intermediate 2, 2.02g triethylamine to 1.26g DIC (N,N-diisopropylcarbodiimide ) in 150mL dichloromethane solution, and stirred at room temperature and under the protection of N ₂ for 3h. After the reaction, the solvent dichloromethane was distilled off under reduced pressure, and n-hexane was added for recrystallization, filtered, and vacuum-dried to obtain a flame retardant .

Example 2

Preparation of flame retardant:

S1. Add 0.2mol cyanuric chloride and 300mL tetrahydrofuran into a four-neck flask with a mechanical stirring device, stir to dissolve and maintain the temperature of the system at 25°C, and dissolve 0.66mol of N-methylacrylamine in an appropriate amount of tetrahydrofuran , and added dropwise in the four-necked flask under stirring, after all the dropwise addition was completed, the reaction solution was warmed up to 50°C, and continued to react at this temperature for 48h (in the reaction process, the NaOH solution with a concentration of 0.1mol/L was used to maintain pH value above 10), after the reaction, most of the tetrahydrofuran solvent was removed by rotary evaporation, then extracted 3 times with toluene, the organic phase was washed 4 times with saturated NaCl aqueous solution, dried with anhydrous sodium sulfate, suction filtered, and concentrated under reduced pressure , to obtain intermediate 1;

S2. Add 0.042mol mercaptoethylamine and 220mL methanol aqueous solution (the volume ratio of methanol to distilled water is 10:1) into a four-necked flask with a stirring device, stir to dissolve and maintain the temperature of the system at 70°C. 5.76g Intermediate 1 and 0.44g of AIBN (azobisisobutyronitrile) were dissolved in an appropriate amount of methanol, and were added dropwise into a four-neck flask under stirring, and reacted at 70°C for 4 hours. After the reaction, cooled to room temperature, Filtration, the filter cake was washed 4 times with methanol and deionized water successively, and dried in vacuum to obtain intermediate 2;

S3, under the protection of N ₂ , add 0.04mol p-carboxyphenylphosphonic acid, 8.86g intermediate 2, 4.04g triethylamine to 2.52g DIC (N,N-diisopropylcarbodiimide ) in 300mL dichloromethane solution, and stirred at room temperature and under the protection of N ₂ for 3h. After the reaction, the solvent dichloromethane was distilled off under reduced pressure, and n-hexane was added for recrystallization, filtered, and vacuum-dried to obtain a flame retardant .

Example 3

The sheath layer is made of a rubber material, and the rubber material includes raw materials of the following weight: 100 g of polyperfluoroethylene propylene resin, 35 g of ABS resin, 30 g of mica powder, 15 g of fumed white carbon black, 20 g of magnesium hydroxide, and 1 prepared flame retardant 2g, vulcanizing agent 1g, heat stabilizer 3g;

After mixing the raw materials, they were put into an internal mixer and kneaded for 20 minutes, and then vulcanized by a flat vulcanizer to obtain rubber materials.

Example 4

The sheath layer is made of rubber material, and the rubber material includes raw materials of the following weight: 100 g of polyperfluoroethylene propylene resin, 40 g of ABS resin, 35 g of mica powder, 17 g of fumed white carbon black, 25 g of magnesium hydroxide, and 2. Prepared flame retardant 2.5g, vulcanizing agent 1.5g, heat stabilizer 4g;

After mixing the raw materials, they were put into an internal mixer and kneaded for 25 minutes, and then vulcanized by a flat vulcanizer to obtain rubber materials.

Example 5

The sheath layer is made of rubber material, and the rubber material includes raw materials of the following weight: 100 g of polyperfluoroethylene propylene resin, 45 g of ABS resin, 40 g of mica powder, 19 g of fumed white carbon black, 30 g of magnesium hydroxide, and 1 prepared flame retardant 3g, vulcanizing agent 2g, heat stabilizer 5g;

After mixing the raw materials, put them into an internal mixer and knead for 30 minutes, and then use a flat vulcanizer to vulcanize to obtain rubber materials.

To the rubber material that embodiment 3-5 obtains, be processed into standard test sample, carry out following performance test:

Mechanical properties: use electronic universal testing machine for test and characterization (dumbbell-shaped standard sample with a length of 50mm, keep 200mm/min for tensile test);

Flame retardant performance: use a digital display oxygen index meter to test the oxygen index LOI of the material (sample size 100x6.5x3mm ³ ); use a horizontal and vertical combustion tester to test the UL-94 vertical combustion level (sample size is 100x13x3mm ³ );

The measured results are shown in the table below:

Example 3 Example 4 Example 5 Tensile strength/MPa 30.3 31.2 30.8 Elongation at break/% 1270 1355 1295 Oxygen Index/% 31.2 31.6 31.5 UL-94 rating V-0 V-0 V-0

It can be seen from the data in the above table that the rubber material prepared by the present invention has higher mechanical properties and excellent flame retardancy.

Example 6

A low-noise flexible cable, comprising a conductor, an insulating layer, a braided shielding layer and a sheath layer arranged sequentially from inside to outside;

The conductor is made of twisted copper wires, the insulating layer is coated on the outer wall of the conductor by wrapping and sintering the polytetrafluoroethylene film, the surface of the insulating layer is coated with semi-insulating polysilicon material, and the braided shielding layer is wrapped on the outside of the insulating layer and passed through The semi-insulating polysilicon material is attached to the outer wall of the insulating layer, and the rubber material obtained in Example 3 is used for the sheath layer to cover the outside of the braided shielding layer.

Example 7

A low-noise flexible cable, comprising a conductor, an insulating layer, a braided shielding layer and a sheath layer arranged sequentially from inside to outside;

The conductor is made of twisted copper wires, the insulating layer is coated on the outer wall of the conductor by wrapping and sintering the polytetrafluoroethylene film, the surface of the insulating layer is coated with semi-insulating polysilicon material, and the braided shielding layer is wrapped on the outside of the insulating layer and passed through The semi-insulating polysilicon material is bonded to the outer wall of the insulating layer, and the rubber material prepared in Example 4 is used for the sheath layer to cover the outside of the braided shielding layer.

Example 8

A low-noise flexible cable, comprising a conductor, an insulating layer, a braided shielding layer and a sheath layer arranged sequentially from inside to outside;

The conductor is made of twisted copper wires, the insulating layer is coated on the outer wall of the conductor by wrapping and sintering the polytetrafluoroethylene film, the surface of the insulating layer is coated with semi-insulating polysilicon material, and the braided shielding layer is wrapped on the outside of the insulating layer and passed through The semi-insulating polysilicon material is attached to the outer wall of the insulating layer, and the rubber material obtained in Example 5 is used for the sheath layer to cover the outside of the braided shielding layer.

The cables of Examples 6-8 were tested according to the GB/T17737.1 standard for the cable's own pulse signal (the lower the cable's own pulse signal, the lower the noise), and the results are shown in the table below:

Example 6 Example 7 Example 8 Self pulse signal/mV 0.82 0.77 0.79

It can be seen from the data in the above table that the cable obtained by the present invention has low noise characteristics.

In the description of the specification, descriptions referring to the terms "one embodiment", "example", "specific example" and the like mean that specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one of the present invention. Examples or examples. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above content is only an example and description of the present invention. Those skilled in the art will make various modifications or supplements to the described specific embodiments or replace them in similar ways, as long as they do not deviate from the invention or exceed the rights of the present invention. The scope defined in the claims should all belong to the protection scope of the present invention.

Claims (9)

1. The utility model provides a low noise flexible cable, its characterized in that includes conductor, insulating layer, braided shield and restrictive coating that from interior to exterior set gradually, the conductor adopts the copper wire transposition to form, and the insulating layer scribbles the semi-conductive glue through wrapping sintering cladding in the conductor outer wall, insulating layer surface, and the braided shield cladding is outside and through the laminating of semi-conductive glue and insulating layer outer wall at the insulating layer, and the restrictive coating cladding is outside at the braided shield.

2. A low noise flexible cable according to claim 1, wherein said insulating layer is made of teflon.

3. The low noise flexible cable according to claim 1, wherein the semi-conductive adhesive is made of a semi-insulating polysilicon material.

4. The low-noise flexible cable according to claim 1, wherein the sheath layer is made of a rubber material, and the rubber material comprises the following raw materials in parts by weight: 100 parts of fluorinated ethylene propylene resin, 35-45 parts of ABS resin, 30-40 parts of mica powder, 15-19 parts of fumed silica, 20-30 parts of magnesium hydroxide, 2-3 parts of flame retardant, 1-2 parts of vulcanizing agent and 3-5 parts of heat stabilizer.

5. The low noise flexible cable according to claim 4, wherein the flame retardant is prepared by the steps of:

s1, adding cyanuric chloride and tetrahydrofuran into a four-neck flask with a mechanical stirring device, stirring to dissolve, maintaining the temperature of a system at 25 ℃, dissolving N-methylacrylamine into a proper amount of tetrahydrofuran, dropwise adding the N-methylacrylamine into the four-neck flask under stirring, heating a reaction solution to 50 ℃ after all dropwise adding is finished, continuing reacting for 48 hours at the temperature, removing most tetrahydrofuran solvent by rotary evaporation after the reaction is finished, extracting for 2-3 times by using toluene, washing an organic phase by using a saturated NaCl aqueous solution for 3-4 times, drying by using anhydrous sodium sulfate, carrying out suction filtration and reduced pressure concentration to obtain an intermediate 1;

s2, adding mercaptoethylamine and a methanol aqueous solution into a four-neck flask with a stirring device, stirring to dissolve, maintaining the temperature of a system at 70 ℃, dissolving the intermediate 1 and AIBN into a proper amount of methanol, dropwise adding the intermediate 1 and AIBN into the four-neck flask under stirring, reacting for 4 hours at 70 ℃, cooling to room temperature after the reaction is finished, filtering, washing a filter cake with methanol and deionized water respectively for 3-4 times, and performing vacuum drying to obtain an intermediate 2;

s3, in N ₂ Under protection, p-carboxyphenylphosphonic acid,The intermediate 2 and triethylamine are added into dichloromethane solution dissolved with DIC and then mixed at room temperature and N ₂ Stirring and reacting for 3h under protection, after the reaction is finished, distilling under reduced pressure to remove a solvent dichloromethane, adding n-hexane for recrystallization, filtering, and drying in vacuum to obtain the flame retardant.

6. The flexible low-noise cable according to claim 5, wherein the pH of the reaction solution is maintained at 10 or more by using NaOH solution with a concentration of 0.1mol/L during the reaction in step S1.

7. The flexible low-noise cable according to claim 5, wherein the ratio of the amounts of cyanuric chloride, tetrahydrofuran and N-methylacrylamine used in step S1 is 0.1 mol.

8. The flexible cable of claim 5, wherein the ratio of the amounts of mercaptoethylamine, aqueous methanol, intermediate 1 and AIBN used in step S2 is 0.021mol.

9. A low noise flexible cable according to claim 5, wherein the ratio of the amounts of p-carboxyphenylphosphonic acid, intermediate 2, triethylamine, DIC and dichloromethane in step S3 is 0.02mol.