A composite cable with high insulation performance and its preparation method

Abstract

The present invention belongs to the technical fields of polymer materials and wire and cable, and discloses a composite cable with high insulation performance and a preparation method thereof. The preparation method is as follows: A hydroxyl-terminated hydrogen-containing polysiloxane is copolymerized with a diol and a diisocyanate to obtain an organosilicon-modified polyurethane elastomer solution; then a vinyl crosslinking agent is added for crosslinking reaction, and after the reaction is completed, it is dried and granulated to obtain organosilicon-modified polyurethane elastomer pellets; then the elastomer pellets are mixed uniformly with PE, EVA and a reinforcing filler, and extruded into a mold containing a metal wire for coating and curing to form an insulating layer; finally, nylon chips and a color masterbatch are mixed and injection-coated on the surface of the insulating layer and cured to form a composite cable with high insulation performance. In the present invention, the insulating layer uses a specific TPE material to blend and modify PE, which can significantly improve its strength, toughness and heat aging resistance, and can maintain high insulation performance.

Description

Technical Field

[0001] The present invention belongs to the technical fields of polymer materials and wire and cable, and particularly relates to a composite cable with high insulation performance and a preparation method thereof. Background Art

[0002] Insulating materials used for cables mainly include polyvinyl chloride (PVC), polyethylene (PE), cross-linked polyethylene (XLPE), rubber, silicone rubber, etc. PVC has good insulation, chemical resistance and easy processing characteristics, but has poor high temperature resistance, weather resistance and flexibility. PE has good flexibility and easy processing characteristics, but has poor high temperature resistance and weather resistance. XLPE can improve the high temperature resistance and mechanical properties of PE to a certain extent, but has limited improvement effect on weather resistance. Rubbers such as ethylene-propylene rubber and silicone rubber have excellent aging resistance, electrical insulation and chemical resistance, but have low hardness and poor thermoplastic processing performance.

[0003] Thermoplastic elastomer (TPE) has been increasingly widely used in insulating materials such as cables because it has excellent properties such as high elasticity, aging resistance and oil resistance of traditional cross-linked vulcanized rubber, and at the same time has the characteristics of convenient processing and wide processing methods of ordinary plastics. For example, the invention patent with the publication number of CN 117894529 A discloses a preparation method of a high-toughness cable, using a composite material of nano-composite powder and organosilicon thermoplastic elastomer to coat the outside of a conductor to form an insulating layer, thereby improving the toughness and strength of the cable. However, the strength and aging resistance of the composite insulating material used therein need to be further improved, resulting in a reduction in the protection durability and insulation stability of the cable. Summary of the Invention

[0004] Aiming at the above-mentioned shortcomings and deficiencies of the prior art, the primary object of the present invention is to provide a preparation method of a composite cable with high insulation performance.

[0005] Another object of the present invention is to provide a composite cable with high insulation performance prepared by the above method.

[0006] The present invention uses a TPE insulating material + nylon sheath with excellent insulation performance and higher strength, which can achieve insulation performance equivalent to that of conventional PVC materials, and has higher strength and high temperature resistance characteristics. It can meet the anti-impact protection and insulation stability under higher voltages with a lower thickness of the coating layer, reducing the volume of the wire and the cost.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] A preparation method of a composite cable with high insulation performance, comprising the following preparation steps:

[0009] (1) React the hydroxyl-terminated hydrogen-containing polysiloxane with a diol and a diisocyanate under the conditions of an organic solvent and an organotin catalyst to obtain a solution of an organosilicon-modified polyurethane elastomer; then add a vinyl crosslinking agent and a chloroplatinic acid solution catalyst and continue the heat preservation crosslinking reaction. After the reaction is completed, dry and granulate to obtain organosilicon-modified polyurethane elastomer pellets;

[0010] (2) Add the obtained organosilicon-modified polyurethane elastomer pellets, polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), and a reinforcing filler to a mixer and melt-knead evenly, and then extrude into a mold with a metal wire placed therein for coating and curing to form an insulating layer;

[0011] (3) Add nylon chips and a color masterbatch to an injection molding machine, heat and melt them, and then injection mold and coat them on the surface of the insulating layer for curing to form a high-insulation performance composite cable.

[0012] In the above preparation method, the hydroxyl-terminated hydrogen-containing polysiloxane has the following molecular structural formula:

[0013] In the formula, x is an integer from 0 to 100, and y is an integer from 10 to 100. It is a commonly used raw material in the art and can be obtained by ring-opening polymerization of hydrogen-containing cyclic siloxanes or by ring-opening copolymerization of hydrogen-containing cyclic siloxanes and methyl cyclic siloxanes.

[0014] In the above preparation method, the diol is a polyether diol (such as ethylene glycol polyether, propylene glycol polyether, etc.) or a polyester diol (such as ethylene glycol adipate diol, butylene glycol adipate diol, polycaprolactone diol, polycarbonate diol, etc.) with a molecular weight of 500 to 3000; preferably a polyester diol. Using a polyester diol as the soft segment of the polyurethane elastomer in the present invention can further improve the strength.

[0015] In the above preparation method, the diisocyanate is one or more of 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and hexamethylene diisocyanate.

[0016] In the above preparation method, the organic solvent is one or more of toluene, benzene, ethyl acetate, and N,N-dimethylformamide.

[0017] In the above preparation method, the molar ratio of the hydroxyl-terminated hydrogen-containing polysiloxane to the diol and the diisocyanate in the reaction is 1:1 to 2:2 to 4.

[0018] In the above preparation method, the vinyl crosslinking agent is one or more of divinylbenzene, terminal diene (such as 1,5 - hexadiene, 1,6 - heptadiene, 1,7 - octadiene, 1,8 - nonadiene, etc.), and terminal vinyl polydimethylsiloxane. Terminal vinyl polydimethylsiloxane with a molecular weight of 1000 - 3000 is preferred. Using terminal vinyl polydimethylsiloxane as the crosslinking agent for polyurethane elastomer in the present invention can significantly improve the strength of the elastomer, and at the same time, the obtained elastomer has better flexibility and heat - aging resistance compared with other crosslinking agents.

[0019] In the above preparation method, the addition amount of the vinyl crosslinking agent is 5% - 40% of the mass of the hydroxyl - terminated hydrogen - containing polysiloxane.

[0020] In the above preparation method, the temperature of the reaction and the heat - preservation crosslinking reaction is 70 - 90 °C, and the time is 2 - 6 h.

[0021] In the above preparation method, the reinforcing filler is one or more of nano - calcium carbonate, nano - silica, and nano - kaolin.

[0022] In the above preparation method, the mass - part ratio of the organosilicon - modified polyurethane elastomer pellets, PE, EVA, and the reinforcing filler added is: 10 - 40 parts of the organosilicon - modified polyurethane elastomer pellets, 60 - 100 parts of PE, 5 - 20 parts of EVA, and 5 - 15 parts of the reinforcing filler.

[0023] A high - insulation composite cable is prepared by the above method.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] (1) The insulating layer of the composite cable of the present invention uses organosilicon - modified polyurethane elastomer to blend - modify the PE matrix, which can significantly improve its strength, toughness, and heat - aging resistance, and can maintain a high insulation performance.

[0026] (2) The present invention further conducts a crosslinking reaction on the organosilicon - modified polyurethane elastomer, while further improving its strength and heat - aging resistance, ensuring good toughness.

[0027] (3) By adding a certain amount of EVA to the insulating layer of the present invention, the blending - modification effect of the organosilicon - modified polyurethane elastomer and the PE substrate can be significantly improved, thereby improving the comprehensive performance. Detailed implementation mode

[0028] The following combines examples to further describe the present invention in detail, but the implementation modes of the present invention are not limited thereto.

[0029] Example 1

[0030] A preparation method of a composite cable with high insulation performance, comprising the following preparation steps:

[0031] (1) Under nitrogen protection, a hydroxyl-terminated hydrogen-containing polysiloxane with a hydrogen content of 0.65 wt%, a molecular weight of 3000 (hydroxyl value 37 mgKOH / g), a butanediol adipate diol with a molecular weight of 1000, and 4,4'-diphenylmethane diisocyanate are heated to 80 °C and reacted for 3 h under the conditions of toluene solvent and organotin catalyst in a molar ratio of 1:1.5:3 to obtain an organosilicon-modified polyurethane elastomer solution. Then, a vinyl crosslinking agent (divinylbenzene, 1,7-octadiene, and a vinyl-terminated polydimethylsiloxane with a molecular weight of 2000 (vinyl content 2.8 wt%)) accounting for 20% of the mass of the hydroxyl-terminated hydrogen-containing polysiloxane and a chloroplatinic acid solution catalyst are added, and the crosslinking reaction is continued under insulation for 4 h. After the reaction is completed, it is dried and granulated to obtain organosilicon-modified polyurethane elastomer pellets.

[0032] (2) The obtained organosilicon-modified polyurethane elastomer pellets, PE material, EVA material, and nano calcium carbonate filler are added to a mixer in a mass ratio of 20:80:10:10, melt-kneaded evenly, and then extruded into a mold with a metal wire placed inside for coating and curing to form an insulating layer.

[0033] (3) Nylon 66 chips and color masterbatch are added to an injection molding machine, heated and melted, and then injection molded and coated on the surface of the insulating layer for curing to form a composite cable with high insulation performance.

[0034] The insulation performance (measuring volume resistivity), tensile strength, elongation at break (GB / T 528-2009), and heat aging performance (GB / T 7141-2008, exposure temperature 110 °C, time 240 h; then testing the tensile strength retention rate) of the insulating layers obtained in this example under different vinyl crosslinking agent conditions are tested, and the uncrosslinked organosilicon-modified polyurethane elastomer and the insulating layer obtained without adding the organosilicon-modified polyurethane elastomer (control group) are used for comparison. The results are shown in Table 1 below.

[0035] Table 1

[0036]

[0037]

[0038] It can be seen from the results in Table 1 that the insulating layer of the composite cable of the present invention has a high volume resistivity and excellent insulation performance. By crosslinking the organosilicon-modified polyurethane elastomer, the strength and heat aging performance of the obtained insulating layer can be significantly improved, and the insulating layer obtained by using vinyl-terminated polydimethylsiloxane as the crosslinking agent has better flexibility and heat aging performance compared with other crosslinking agents.

[0039] Example 2

[0040] A preparation method of a high-insulation composite cable, comprising the following preparation steps:

[0041] (1) Under nitrogen protection, a hydroxyl-terminated hydrogen-containing polysiloxane with a hydrogen content of 0.65 wt%, a molecular weight of 3000 (hydroxyl value 37 mgKOH / g), a butanediol adipate diol with a molecular weight of 1000, and p-phenylene diisocyanate are heated to 85 °C and reacted for 4 h under the conditions of toluene solvent and organotin catalyst according to a molar ratio of 1:1:2 to obtain an organosilicon-modified polyurethane elastomer solution. Then, a vinyl crosslinking agent (vinyl-terminated polydimethylsiloxane with a molecular weight of 1000 (vinyl content 5.6 wt%)) accounting for 5% of the mass of the hydroxyl-terminated hydrogen-containing polysiloxane and a chloroplatinic acid solution catalyst are added, and the crosslinking reaction is continued for 4 h while maintaining the temperature. After the reaction is completed, it is dried and granulated to obtain organosilicon-modified polyurethane elastomer pellets.

[0042] (2) The obtained organosilicon-modified polyurethane elastomer pellets, PE material, EVA material, and nano-silica filler are added to a mixer according to a mass ratio of 40:100:20:15, melted and kneaded evenly, and then extruded into a mold with a metal wire placed therein for coating and curing to form an insulating layer.

[0043] (3) Nylon 66 chips and color masterbatch are added to an injection molding machine, heated and melted, and then injection molded and coated on the surface of the insulating layer for curing to form a high-insulation composite cable.

[0044] The insulating layer obtained in this example has a volume resistivity of 1.4*10 15 Ω·cm, a tensile strength of 35 MPa, an elongation at break of 514%, and a heat aging strength retention rate of 90%.

[0045] Example 3

[0046] A preparation method of a high-insulation composite cable, comprising the following preparation steps:

[0047] (1) Under nitrogen protection, a hydroxyl-terminated hydrogen-containing polysiloxane with a hydrogen content of 0.65 wt%, a molecular weight of 3000 (hydroxyl value 37 mgKOH / g), a polycarbonate diol with a molecular weight of 1000, and isophorone diisocyanate are heated to 90 °C and reacted for 2 h under the conditions of toluene solvent and organotin catalyst according to a molar ratio of 1:2:4 to obtain an organosilicon-modified polyurethane elastomer solution. Then, a vinyl crosslinking agent (vinyl-terminated polydimethylsiloxane with a molecular weight of 3000 (vinyl content 1.9 wt%)) accounting for 40% of the mass of the hydroxyl-terminated hydrogen-containing polysiloxane and a chloroplatinic acid solution catalyst are added, and the crosslinking reaction is continued for 4 h while maintaining the temperature. After the reaction is completed, it is dried and granulated to obtain organosilicon-modified polyurethane elastomer pellets.

[0048] (2) The obtained organosilicon-modified polyurethane elastomer pellets, PE material, EVA material, and nano-silica filler are added to a kneader in a mass ratio of 10:60:5:5, melt-kneaded uniformly, and then extruded into a mold with metal wires placed therein for coating and curing to form an insulating layer.

[0049] (3) Nylon 66 chips and color masterbatch are added to an injection molding machine, heated and melted, and then injection-molded and coated on the surface of the insulating layer for curing to form a high-insulation performance composite cable.

[0050] The insulating layer obtained in this example has a volume resistivity of 1.7×10 15 Ω·cm, a tensile strength of 49 MPa, an elongation at break of 350%, and a heat aging strength retention rate of 91%.

[0051] Example 4

[0052] A preparation method of a high-insulation performance composite cable. Compared with Example 1, propylene glycol polyether with a molecular weight of 1000 is used to replace adipic acid butanediol diol, and the vinyl cross-linking agent is vinyl-terminated polydimethylsiloxane with a molecular weight of 2000, and the rest are the same.

[0053] The insulating layer obtained in this example has a volume resistivity of 1.6×10 15 Ω·cm, a tensile strength of 32 MPa, an elongation at break of 370%, and a heat aging strength retention rate of 92%.

[0054] From the comparison results of this example and Example 1, it can be seen that using polyester diol as the soft segment of the polyurethane elastomer in the present invention can further improve the strength of the obtained insulating layer compared with polyether diol.

[0055] Comparative Example 1

[0056] Compared with Example 1 in this comparative example, EVA material is not added in the preparation of the insulating layer, and the vinyl cross-linking agent is vinyl-terminated polydimethylsiloxane with a molecular weight of 2000, and the rest are the same.

[0057] The insulating layer obtained in this example has a volume resistivity of 1.5×10 15 Ω·cm, a tensile strength of 34 MPa, an elongation at break of 338%, and a heat aging strength retention rate of 85%.

[0058] From the comparison results of this comparative example and Example 1, it can be seen that without adding EVA, the comprehensive performance of the insulating layer decreases significantly. The reason is that EVA can significantly improve the blending and modification effect of the organosilicon-modified polyurethane elastomer and the PE substrate in the present invention, thereby improving the comprehensive performance.

[0059] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of a composite cable with high insulation performance, characterized in that, It includes the following preparation steps: (1) React a hydroxyl-terminated hydrogen-containing polysiloxane with a diol and a diisocyanate under the conditions of an organic solvent and an organotin catalyst to obtain a solution of an organosilicon-modified polyurethane elastomer; then add a vinyl crosslinking agent and a chloroplatinic acid solution catalyst and continue the heat-insulated crosslinking reaction. After the reaction is completed, dry and granulate to obtain organosilicon-modified polyurethane elastomer pellets; the hydroxyl-terminated hydrogen-containing polysiloxane has the following molecular structural formula: , where x is an integer from 0 to 100 and y is an integer from 10 to 100; The molar ratio of the reaction of the hydroxyl-terminated hydrogen-containing polysiloxane with the diol and the diisocyanate is 1:1~2:2~4; The vinyl crosslinking agent uses a vinyl-terminated polydimethylsiloxane with a molecular weight of 1000~3000; the addition amount of the vinyl crosslinking agent is 5%~40% of the mass of the hydroxyl-terminated hydrogen-containing polysiloxane; (2) Add the obtained organosilicon-modified polyurethane elastomer pellets, PE, EVA and a reinforcing filler to a mixer and melt and knead evenly, and then extrude into a mold with a metal wire placed therein for coating and curing to form an insulating layer; (3) Add nylon chips and a color masterbatch to an injection molding machine, heat and melt them, and then injection mold and coat the surface of the insulating layer for curing to form a composite cable with high insulation performance.

2. The preparation method of a composite cable with high insulation performance according to claim 1, characterized in that, The diol uses a polyether diol or a polyester diol with a molecular weight of 500~3000; the diisocyanate uses one or more of 4,4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and hexamethylene diisocyanate.

3. The preparation method of a composite cable with high insulation performance according to claim 1, characterized in that, The organic solvent uses one or more of toluene, benzene, ethyl acetate, and N,N-dimethylformamide.

4. The preparation method of a composite cable with high insulation performance according to claim 1, characterized in that, The temperature of the reaction and the heat-insulated crosslinking reaction is 70~90°C, and the time is 2~6 h; the reinforcing filler uses one or more of nano calcium carbonate, nano silica, and nano kaolin.

5. The preparation method of a composite cable with high insulation performance according to claim 1, characterized in that, The mass part ratio of the addition of the organosilicon-modified polyurethane elastomer pellets, PE, EVA and the reinforcing filler is: 10~40 parts of the organosilicon-modified polyurethane elastomer pellets, 60~100 parts of PE, 5~20 parts of EVA, and 5~15 parts of the reinforcing filler.

6. A composite cable with high insulation performance, characterized in that, It is prepared by the method according to any one of claims 1 to 5.

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