A migration-resistant, environmentally friendly flexible PVC sheathed cable

Abstract

The invention belongs to the technical field of cable protective layer materials, and particularly relates to a migration-resistant environmentally friendly flexible PVC sheathed cable, comprising one or more core units, each core unit comprising a conductor core, a shielding layer coaxially tightly wrapped outside the conductor core, and an insulating layer coaxially tightly wrapped outside the shielding layer. All the core units are twisted together as a whole, coaxially tightly wrapped by a flame retardant layer, and a PVC sheath layer coaxially tightly wrapped outside the flame retardant layer. Polyacrylate-based phthalate molecular imprinted microspheres are distributed in the PVC sheath layer. These imprinted microspheres form a combination and containment of phthalate plasticizer molecules in the sheath, thereby reducing the migration of plasticizer molecules in the cable sheath to the cable surface.

Description

Technical Field

[0001] The invention belongs to the technical field of cable protective layer materials, and in particular relates to a migration-resistant and environment-friendly flexible PVC sheathed cable. Background Art

[0002] Polyvinyl chloride is a common plastic material with good insulation and can effectively block electric current; it has good chemical corrosion resistance and can often be used in harsh environmental conditions, such as moisture, acid, alkali and other corrosive media; it has high mechanical strength and wear resistance, can withstand a certain amount of tension and pressure, so that the product is not easily damaged during use and has a long service life; it also has good fire resistance and flame retardant properties, safety and reliability, and low cost. This makes PVC cables widely used in power transmission and electrical equipment.

[0003] However, due to the large intermolecular polarity of PVC materials, a large amount of plasticizers need to be added to improve their flexibility and processability. However, plasticizers are easy to migrate from the product to the outside, especially under the influence of heat, pressure and other environmental factors. After the plasticizers migrate out of the PVC cable, they will pollute the soil where the cable is located, and it is easy to endanger human health after contact with the environment. Therefore, controlling the migration of plasticizers is of great significance in terms of environmental protection, and has always been a focus in the field of PVC cables.

[0004] Among them, phthalates are the most widely used plasticizer in the field of PVC products. Compared with some large molecular weight plasticizers, phthalates and other plasticizers with smaller molecular weight are more likely to migrate out of the PVC matrix. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a migration-resistant and environment-friendly flexible PVC sheathed cable, comprising one or more core units, each core unit comprising a conductor core, a shielding layer coaxially tightly wrapped outside the conductor core, and an insulating layer coaxially tightly wrapped outside the shielding layer. All the core units are twisted together as a whole, coaxially tightly wrapped by a flame retardant layer, and a PVC sheath layer coaxially tightly wrapped outside the flame retardant layer.

[0006] The PVC sheath layer is calculated by weight and includes 100 parts of PVC, 5-15 parts of polyacrylate-based phthalate molecular imprinted microspheres, 20-40 parts of phthalate plasticizers, 2-4 parts of stabilizers, 1-2 parts of lubricants, 0.5-1 parts of antioxidants, and 5-10 parts of white carbon black.

[0007] The preparation method of polyacrylate-based phthalate molecular imprinted microspheres is as follows: after fully mixing acrylate monomers, crosslinking monomers, and phthalate template molecules in a solvent at a weight ratio of 1-4:5-15:1, an initiator is added thereto and dispersed sufficiently, the mixture is heated to 70-80°C under a protective atmosphere for reaction for 10-20 hours, the mixture is naturally cooled to room temperature, and then filtered to obtain a crude product, the obtained crude product is first fully washed with acetone, dried, ball-milled, and then fully washed with an acetic acid alcohol dispersion to remove the phthalate template molecules, and then fully washed with ethanol to remove the residual acetic acid, and then vacuum dried;

[0008] As a preferred embodiment: each conductor core is respectively formed by twisting a number of round copper wires; there are more than two core units, and the gaps between the core units inside the flame retardant layer are filled with filling ropes;

[0009] Preferably, the acrylate monomer is methyl methacrylate, butyl methacrylate, glycidyl methacrylate, etc., the crosslinking monomer is ethylene glycol dimethacrylate, etc., the solvent is toluene, xylene, diphenyl ether or ethyl acetate, etc., the initiator is azobisisobutyronitrile, etc., the mass concentration of acetic acid in the alcohol dispersion of acetic acid is 10% to 15%, and the alcohol used as the solvent is ethanol or methanol;

[0010] Preferably, the phthalate plasticizer is dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, diisodecyl phthalate, diphenyl phthalate, etc.

[0011] As a preferred embodiment: the stabilizer is zinc stearate, lead stearate, calcium stearate, etc.;

[0012] As a preferred embodiment: the lubricant is polyethylene wax, hydroxy silicone oil, etc.;

[0013] Preferably, the antioxidant is antioxidant 1010, antioxidant 1076, etc.

[0014] As a preference: the preparation operation of the above PVC sheathed cable is:

[0015] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly coated on the shielding layer is formed, thereby obtaining a core unit; all the core units (and the filling ropes used to fill the gaps) are matched together in parallel and then twisted, and then the twisted core units (and the filling ropes) are evenly and tightly wrapped with mica tape as a whole, thereby forming a flame retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch is melted in an extruder and evenly extruded on the flame retardant layer, thereby forming a PVC sheath layer coaxially and tightly coated with the flame retardant layer.

[0016] The preparation operation of the PVC jacket layer masterbatch is as follows: PVC, polyacrylate-based phthalate molecular imprinted microspheres, phthalate plasticizers, stabilizers, lubricants, antioxidants, and white carbon black are fully mixed together, and then added into a twin-screw extruder at 150-175° C. for extrusion and granulation;

[0017] In addition, the filling rope is fluffy and elastic in its natural state. Therefore, during the concentrated twisting and mica tape wrapping process, the filling rope is further squeezed by the core unit or the mica tape, and the gap can be basically filled.

[0018] The beneficial effects of the present invention are as follows: polyacrylate-based phthalate molecular imprinted microspheres are added to PVC, and the imprinted microspheres are concentrated with specific binding sites for phthalates, and because the imprinted microspheres themselves are formed by cross-linking based on a relatively high proportion of acrylic acid ester cross-linking monomers, the chemical structure is relatively stable, and after being added to the PVC matrix and extruded, the imprinted microspheres still retain the binding property for phthalate plasticizer molecules. These imprinted microspheres are distributed in the sheath matrix, and can form binding and restraint on the phthalate plasticizer molecules nearby (the applicant believes that the reason why the plasticizer molecules can gradually migrate out from the inside of the product indicates that the plasticizer molecules also have certain activity in the product, and it is precisely because of this activity of the plasticizer molecules that they can also contact and bind with the imprinted microspheres in the sheath product), thereby effectively reducing the migration of plasticizer molecules in the cable sheath to the external environment, and also reducing the adverse effects on the cable surrounding environment and organisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a distribution diagram of the internal layer structure of the migration-resistant, environment-friendly flexible PVC sheathed cable of the present invention (radial cross-sectional view),

[0020] Among them, 1 is the conductor core, 2 is the shielding layer, 3 is the insulation layer, 4 is the flame retardant layer, 5 is the PVC sheath layer, and 6 is the filling rope. DETAILED DESCRIPTION

[0021] Example 1

[0022] (1) Preparation of polyacrylate-based dioctyl phthalate imprinted microspheres

[0023] At room temperature (25°C, the same below), 12 parts of butyl methacrylate, 60 parts of ethylene glycol dimethacrylate, and 6 parts of dioctyl phthalate are mixed in 2000 parts of toluene by weight in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and dispersed sufficiently, the mixture is heated to 73°C in a nitrogen atmosphere and stirred for reaction for 12 hours, the mixture is naturally cooled to room temperature and the stirring is stopped and the mixture is filtered to obtain a crude product, the crude product is first fully washed with acetone and then dried at 60°C, then ball-milled and dispersed to a particle size of 120 to 150 meshes, then fully washed with an ethanol solution of acetic acid with a solute mass concentration of 10% to remove dioctyl phthalate molecules, then fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0024] (2) Preparation of PVC sheath layer masterbatch

[0025] Calculated by weight, 100 parts of PVC (type ‌SG-3), 13 parts of polyacrylate-based dioctyl phthalate imprinted microspheres obtained in step (1) of this embodiment, 40 parts of plasticizer dioctyl phthalate, 1.5 parts of zinc stearate, 1.5 parts of lead stearate, 2 parts of hydroxy silicone oil, 0.5 parts of antioxidant 1010, and 6 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder at 150-175°C (the temperature of the first zone is set to 150°C, the temperature of the second zone is set to 160°C, the temperature of the third zone is set to 165°C, the temperature of the fourth zone is set to 170°C, the temperature of the fifth zone is set to 175°C, and the temperature of the die is set to 170°C, the same below) for extrusion and granulation to obtain a PVC sheath layer masterbatch;

[0026] (3) Preparation of PVC sheathed cable

[0027] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulating layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulating layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a number of filling ropes used to fill the gaps between these core units are fully matched and concentrated together in parallel and then twisted, and then the twisted core units and filling ropes are evenly and tightly wrapped with flame-retardant mica tape as a whole The PVC sheath layer masterbatch obtained in step (2) of this embodiment is added into a twin-screw extruder at 150-175°C (the temperature of zone 1 is set at 150°C, the temperature of zone 2 is set at 160°C, the temperature of zone 3 is set at 165°C, the temperature of zone 4 is set at 170°C, the temperature of zone 5 is set at 175°C, and the temperature of the die is set at 175°C, the same below) and is evenly extruded on the flame retardant layer, and after cooling, a PVC sheath layer (the thickness of the PVC sheath layer is about 1.5 mm, the same below) coaxially and tightly covering the flame retardant layer is formed.

[0028] Example 2

[0029] (1) Preparation of polyacrylate-based diisobutyl phthalate imprinted microspheres

[0030] At room temperature, 7 parts of glycidyl methacrylate, 8 parts of butyl methacrylate, 50 parts of ethylene glycol dimethacrylate, and 5 parts of diisobutyl phthalate are mixed in 1800 parts of xylene by weight and fully mixed in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and fully dispersed, the mixture is heated to 75° C. in a nitrogen atmosphere and stirred for reaction for 12 hours, the mixture is naturally cooled to room temperature and the stirring is stopped and the mixture is filtered to obtain a crude product, the crude product is fully washed with acetone and then dried at 60° C., then ball-milled and dispersed to a particle size of 120 to 150 meshes, then fully washed with an ethanol solution of acetic acid with a solute mass concentration of 10% to remove diisobutyl phthalate molecules, then fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0031] (2) Preparation of PVC sheath layer masterbatch

[0032] Calculated by weight, 100 parts of PVC (type ‌SG-3), 10 parts of polyacrylate-based diisobutyl phthalate imprinted microspheres obtained in step (1) of this embodiment, 30 parts of plasticizer diisobutyl phthalate, 3 parts of zinc stearate, 2 parts of hydroxy silicone oil, 1 part of antioxidant 1010, and 9 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder for extrusion and granulation at 150-175° C. to obtain a PVC sheath layer masterbatch;

[0033] (3) Preparation of PVC sheathed cable

[0034] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a plurality of filling ropes used to fill the gaps between the core units are fully matched and concentrated together in parallel and then twisted, and then the core units and filling ropes twisted together are evenly and tightly wrapped with flame-retardant mica tape as a whole, thereby forming a flame-retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch obtained in step (2) of this embodiment is added to a twin-screw extruder and evenly extruded on the flame-retardant layer at 150-175°C, and after cooling, a PVC sheath layer coaxially and tightly wrapped with the flame-retardant layer is formed.

[0035] Example 3

[0036] (1) Preparation of polyacrylate-based diisodecyl phthalate imprinted microspheres

[0037] At room temperature, 8 parts of methyl methacrylate, 12 parts of butyl methacrylate, 70 parts of ethylene glycol dimethacrylate, and 12 parts of diisodecyl phthalate are mixed in 2500 parts of ethyl acetate by weight and fully mixed in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and fully dispersed, and then heated to 75° C. in a nitrogen atmosphere and stirred for reaction for 12 hours, and then naturally cooled to room temperature and stopped stirring and filtered to obtain a crude product, the obtained crude product is first fully washed with acetone and then dried at 60° C., and then ball-milled and dispersed to a particle size of 120 to 150 meshes, and then fully washed with an ethanol solution of acetic acid with a solute mass concentration of 10% to remove diisodecyl phthalate molecules, and then fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0038] (2) Preparation of PVC sheath layer masterbatch

[0039] Calculated by weight, 100 parts of PVC (type ‌SG-3), 8 parts of polyacrylate-based diisodecyl phthalate imprinted microspheres obtained in step (1) of this embodiment, 30 parts of plasticizer diisodecyl phthalate, 3 parts of lead stearate, 2 parts of hydroxy silicone oil, 1 part of antioxidant 1010, and 5 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder for extrusion and granulation at 150-175° C. to obtain a PVC sheath layer masterbatch;

[0040] (3) Preparation of PVC sheathed cable

[0041] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a plurality of filling ropes used to fill the gaps between the core units are fully matched and concentrated together in parallel and then twisted, and then the core units and filling ropes twisted together are evenly and tightly wrapped with flame-retardant mica tape as a whole, thereby forming a flame-retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch obtained in step (2) of this embodiment is added to a twin-screw extruder and evenly extruded on the flame-retardant layer at 150-175°C, and after cooling, a PVC sheath layer coaxially and tightly wrapped with the flame-retardant layer is formed.

[0042] Comparative Example 1

[0043] In step (1), the polyacrylate is not prepared with imprinted microspheres as the target product, and the remaining operations and components are the same as those in Example 1:

[0044] (1) Preparation of polyacrylate microspheres

[0045] At room temperature, 12 parts of butyl methacrylate and 60 parts of ethylene glycol dimethacrylate are mixed in 2000 parts of toluene by weight and fully mixed in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and fully dispersed, the temperature is raised to 73° C. in a nitrogen atmosphere, and the mixture is stirred for reaction for 12 hours. After the temperature naturally drops to room temperature, the stirring is stopped and the crude product is filtered to obtain the crude product. The crude product is fully washed with acetone and dried at 60° C., then ball-milled and dispersed to a particle size of 120 to 150 meshes, and then washed with an ethanol solution of acetic acid with a solute mass concentration of 10%, fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0046] (2) Preparation of PVC sheath layer masterbatch

[0047] Calculated by weight, 100 parts of PVC (type ‌SG-3), 13 parts of polyacrylate microspheres obtained in step (1) of this embodiment, 40 parts of plasticizer dioctyl phthalate, 1.5 parts of zinc stearate, 1.5 parts of lead stearate, 2 parts of hydroxy silicone oil, 0.5 parts of antioxidant 1010, and 6 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder for extrusion and granulation at 150-175° C. to obtain a PVC sheath layer masterbatch;

[0048] (3) Preparation of PVC sheathed cable

[0049] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a plurality of filling ropes used to fill the gaps between the core units are fully matched and concentrated together in parallel and then twisted, and then the core units and filling ropes twisted together are evenly and tightly wrapped with flame-retardant mica tape as a whole, thereby forming a flame-retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch obtained in step (2) of this embodiment is added to a twin-screw extruder and evenly extruded on the flame-retardant layer at 150-175°C, and after cooling, a PVC sheath layer coaxially and tightly wrapped with the flame-retardant layer is formed.

[0050] Comparative Example 2

[0051] In step (1), polyacrylate is not prepared with imprinted microspheres as the target product, and the remaining operations and components are the same as those in Example 2:

[0052] (1) Preparation of polyacrylate microspheres

[0053] At room temperature, 7 parts of glycidyl methacrylate, 8 parts of butyl methacrylate, and 50 parts of ethylene glycol dimethacrylate are mixed in 1800 parts of xylene by weight and fully mixed in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and fully dispersed, the mixture is heated to 75° C. in a nitrogen atmosphere and stirred for reaction for 12 hours, the mixture is naturally cooled to room temperature and the stirring is stopped and the mixture is filtered to obtain a crude product, the crude product is fully washed with acetone and then dried at 60° C., then ball-milled and dispersed to a particle size of 120 to 150 meshes, then washed with an ethanol solution of acetic acid having a solute mass concentration of 10%, then fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0054] (2) Preparation of PVC sheath layer masterbatch

[0055] Calculated by weight, 100 parts of PVC (type SG-3), 10 parts of polyacrylate microspheres obtained in step (1) of this embodiment, 30 parts of plasticizer diisobutyl phthalate, 3 parts of zinc stearate, 2 parts of hydroxy silicone oil, 1 part of antioxidant 1010, and 9 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder for extrusion and granulation at 150-175° C. to obtain a PVC sheath layer masterbatch;

[0056] (3) Preparation of PVC sheathed cable

[0057] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a plurality of filling ropes used to fill the gaps between the core units are fully matched and concentrated together in parallel and then twisted, and then the core units and filling ropes twisted together are evenly and tightly wrapped with flame-retardant mica tape as a whole, thereby forming a flame-retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch obtained in step (2) of this embodiment is added to a twin-screw extruder and evenly extruded on the flame-retardant layer at 150-175°C, and after cooling, a PVC sheath layer coaxially and tightly wrapped with the flame-retardant layer is formed.

[0058] Comparative Example 3

[0059] In step (1), polyacrylate is not prepared with imprinted microspheres as the target product, and the remaining operations and components are the same as those in Example 3:

[0060] (1) Preparation of polyacrylate microspheres

[0061] At room temperature, 8 parts of methyl methacrylate, 12 parts of butyl methacrylate, and 70 parts of ethylene glycol dimethacrylate are mixed in 2500 parts of ethyl acetate by weight in a reactor with a condensing mechanism, 1 part of azobisisobutyronitrile is added thereto and dispersed sufficiently, the mixture is heated to 75° C. in a nitrogen atmosphere and stirred for reaction for 12 hours, the mixture is naturally cooled to room temperature and the stirring is stopped and filtered to obtain a crude product, the crude product is first fully washed with acetone and then dried at 60° C., then ball-milled and dispersed to a particle size of 120 to 150 meshes, then washed with an ethanol solution of acetic acid having a solute mass concentration of 10%, then fully washed with ethanol to remove residual acetic acid, and then vacuum dried;

[0062] (2) Preparation of PVC sheath layer masterbatch

[0063] Calculated by weight, 100 parts of PVC (type ‌SG-3), 8 parts of polyacrylate microspheres obtained in step (1) of this embodiment, 30 parts of plasticizer diisodecyl phthalate, 3 parts of lead stearate, 2 parts of hydroxy silicone oil, 1 part of antioxidant 1010, and 5 parts of fumed silica are added to a high-speed mixer and stirred thoroughly, and then added to a twin-screw extruder for extrusion and granulation at 150-175° C. to obtain a PVC sheath layer masterbatch;

[0064] (3) Preparation of PVC sheathed cable

[0065] The aluminum-plastic tape is evenly and tightly wrapped on the outer surface of the conductor core to form a shielding layer coaxially arranged with the conductor core; the conventional insulation layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer, and after cooling, an insulation layer coaxially and tightly wrapped on the shielding layer is formed, thereby obtaining a core unit; three such core units and a plurality of filling ropes used to fill the gaps between the core units are fully matched and concentrated together in parallel and then twisted, and then the core units and filling ropes twisted together are evenly and tightly wrapped with flame-retardant mica tape as a whole, thereby forming a flame-retardant layer coaxially arranged with the whole; the PVC sheath layer masterbatch obtained in step (2) of this embodiment is added to a twin-screw extruder and evenly extruded on the flame-retardant layer at 150-175°C, and after cooling, a PVC sheath layer coaxially and tightly wrapped with the flame-retardant layer is formed.

[0066] The migration degree of the plasticizer in the PVC sheath layer of the cable obtained in the above-mentioned embodiments and comparative embodiments was tested respectively. The testing operation was as follows: the prepared PVC sheathed cable was cut to obtain a 5 cm long straight section as a sample (the cross section of the cut surface was kept flush and parallel to the radial direction of the cable), and each sample was horizontally placed in a beaker of a specification of 150 ml, and then 80 ml of ethanol was added to the beaker to immerse the sample, and the beaker was sealed with a plastic film. After being placed at room temperature for 48 hours, the sample in the beaker was carefully taken out and washed by shaking in another 80 ml of ethanol. Wash, shake and wash thoroughly, take out the sample, combine the washing ethanol with the previous soaking ethanol, filter through a filter membrane, and then use high performance liquid chromatography to measure the concentration of the plasticizer in the combined solution (wherein, the chromatographic column is a C18 column (particle size 5μm, size 4.6x250mm), column temperature 35℃, detection wavelength 225nm, mobile phase methanol, flow rate 1.0mL / min, injection volume ‌10μL). The higher the measured concentration, the more plasticizer migrated from the sample; conversely, the lower the measured concentration, the less plasticizer migrated from the sample. In the same embodiment or comparative embodiment, three samples are taken for the above test, and the average is taken, as shown in Table 1.

[0067] The PVC sheath layer of the cable obtained in the above-mentioned embodiments and comparative embodiments was subjected to mechanical property testing according to the standard of GB / T 2951 "General test methods for insulation and sheath materials of electric and optical cables". In the same embodiment or comparative embodiment, three samples were taken for testing and the average was taken, as shown in Table 1.

[0068] Table 1

[0069]

[0070] According to the concentration of plasticizer in about 160mL of the combined liquid detected by liquid chromatography, and according to the approximate mass and composition of the PVC sheath layer on the sample, it can be inferred that the migration rate of the plasticizer in Comparative Example 1 is about 3.25%, by comparison, the migration rate of the plasticizer in Example 1 after the introduction of molecular imprinting modification means is only about 1.4%; the migration rate of the plasticizer in Comparative Example 2 is about 3%, by comparison, the migration rate of the plasticizer in Example 2 after the introduction of molecular imprinting modification means is only about 1.5%; the migration rate of the plasticizer in Comparative Example 3 is about 4%, by comparison, the migration rate of the plasticizer in Example 3 after the introduction of molecular imprinting modification means is only about 2.3%. It can be seen that significant improvements have occurred in all items.

Claims

1. A migration-resistant, environmentally friendly flexible PVC sheathed cable, characterized in that: The PVC sheathed cable comprises one or more core units, each of which comprises a conductor core (1), a shielding layer (2) tightly wrapped around the conductor core (1), and an insulating layer (3) tightly wrapped around the shielding layer (2); all the core units are twisted together as a whole and are tightly wrapped by a flame retardant layer (4); the flame retardant layer (4) is tightly wrapped by a PVC sheath layer (5); The PVC sheath layer (5) comprises, by weight, 100 parts of PVC, 5 to 15 parts of polyacrylate-based phthalate molecular imprinted microspheres, 20 to 40 parts of phthalate plasticizers, 2 to 4 parts of stabilizers, 1 to 2 parts of lubricants, 0.5 to 1 parts of antioxidants, and 5 to 10 parts of white carbon black.

2. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: There are more than two wire core units, and the gaps between the wire core units inside the flame retardant layer (4) are filled with filling ropes (6).

3. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: The preparation method of the polyacrylate-based phthalate molecular imprinted microspheres is as follows: after fully mixing an acrylate monomer, a cross-linking monomer, and a phthalate template molecule in a solvent at a weight ratio of 1-4:5-15:1, an initiator is added thereto and fully dispersed, the mixture is heated to 70-80°C under a protective atmosphere for reaction for 10-20 hours, the mixture is naturally cooled to room temperature, and then filtered to obtain a crude product; the obtained crude product is first fully washed with acetone, dried, ball-milled, and then fully washed with an acetic acid alcohol dispersion to remove the phthalate template molecule; then fully washed with ethanol to remove residual acetic acid, and then vacuum dried.

4. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 3, characterized in that: The acrylic acid ester monomer is methyl methacrylate, butyl methacrylate or glycidyl methacrylate; the cross-linking monomer is ethylene glycol dimethacrylate; and the solvent is toluene, xylene, diphenyl ether or ethyl acetate.

5. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: The phthalate plasticizer is dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, diisodecyl phthalate or diphenyl phthalate.

6. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: The stabilizer is zinc stearate, lead stearate or calcium stearate.

7. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: The lubricant is polyethylene wax or hydroxy silicone oil.

8. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 1, characterized in that: The preparation operation of the PVC sheathed cable is as follows: The aluminum-plastic tape is evenly and tightly wrapped around the outer surface of the conductor core (1) to form the shielding layer (2); the insulating layer masterbatch is melted in an extruder and evenly extruded on the outer surface of the shielding layer (2), and after cooling, the insulating layer (3) tightly wrapped on the shielding layer (2) is formed, thereby obtaining the core unit; all the core units are matched together in parallel and then twisted, and then the twisted core units are evenly and tightly wrapped with mica tape as a whole, thereby forming the flame retardant layer (4); the PVC sheath layer masterbatch is melted in an extruder and evenly extruded on the flame retardant layer (4), thereby forming the PVC sheath layer (5) tightly covering the flame retardant layer (4).

9. The migration-resistant and environment-friendly flexible PVC sheathed cable according to claim 8, characterized in that: The preparation operation of the PVC sheath layer masterbatch is to fully mix the PVC, the polyacrylate-based phthalate molecular imprinted microspheres, the phthalate plasticizer, the stabilizer, the lubricant, the antioxidant, and the white carbon black, and then add them into a twin-screw extruder at 150-175° C. for extrusion and granulation.

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