Cold-resistant high-insulation polyvinyl chloride cable material and preparation method thereof

Abstract

The invention provides a cold-resistant high-insulation polyvinyl chloride cable material and a preparation method thereof, and belongs to the technical field of cables, and the cold-resistant high-insulation polyvinyl chloride cable material comprises the following components by mass: 100 parts of polyvinyl chloride resin; 30 to 40 parts of dioctyl sebacate; 1-7 parts of a composite stabilizer; 5 to 10 parts of nano filler; 0.1 to 0.5 part of an antioxidant; and 1-1.5 parts of a lubricant. According to the cold-resistant high-insulation polyvinyl chloride cable material and the preparation method thereof provided by the invention, the low-temperature performance of the polyvinyl chloride cable material is improved, and the insulation performance of the polyvinyl chloride cable material is also improved, so that the cold-resistant high-insulation polyvinyl chloride cable material is formed and is suitable for wide popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to a cold-resistant high-insulation polyvinyl chloride cable material and a preparation method thereof. Background Art

[0002] Polyvinyl chloride is a very good material with low price and wide source of raw materials. It has the advantages of wear resistance, chemical corrosion resistance, excellent electrical insulation performance and high mechanical strength. It is widely used in various industries, such as in the production of cables.

[0003] Traditional polyvinyl chloride cable materials are easily brittle in low temperature environments and have insufficient insulation performance (volume resistivity is usually less than 1×101 1Ω·cm). In the prior art, plasticizers are mostly single phthalates (such as DOP) and fillers are mostly ordinary calcium carbonate. There is a problem that low-temperature performance and insulation are difficult to improve synergistically, which limits the application of polyvinyl chloride to a certain extent. Therefore, a cold-resistant high-insulation polyvinyl chloride cable material and a preparation method thereof are needed. Summary of the invention

[0004] The object of the present invention is to provide a cold-resistant high-insulation polyvinyl chloride cable material and a preparation method thereof, so as to solve the technical problem that the low-temperature performance and insulation properties of the existing polyvinyl chloride cable materials are difficult to improve in a coordinated manner.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A cold-resistant high-insulation polyvinyl chloride cable material, comprising the following components by mass:

[0007] 100 parts of polyvinyl chloride resin;

[0008] 30-40 parts of dioctyl sebacate;

[0009] 1-7 parts of composite stabilizer;

[0010] 5-10 parts of nano filler;

[0011] Antioxidant 0.1-0.5 parts;

[0012] Lubricant 1-1.5 parts.

[0013] Furthermore, the composite stabilizer is a calcium-zinc composite stabilizer.

[0014] Furthermore, the calcium-zinc composite stabilizer contains 0.5 parts of rare earth additive.

[0015] Furthermore, the nanofiller is nano silicon dioxide.

[0016] Furthermore, the nano-silica is nano-silica whose surface is modified by a silane coupling agent.

[0017] Furthermore, the antioxidant is antioxidant 1010.

[0018] Furthermore, the lubricant is calcium stearate.

[0019] A method for preparing a cold-resistant high-insulation polyvinyl chloride cable material comprises the following steps:

[0020] (1) Weighing polyvinyl chloride resin, dioctyl sebacate, composite stabilizer, nanofiller, antioxidant and lubricant according to the above mass parts;

[0021] (2) putting polyvinyl chloride resin and dioctyl sebacate into a high-speed mixer and mixing them at a temperature of 60° C. for 15 minutes to form a uniform premix;

[0022] (3) adding the composite stabilizer, nanofiller, antioxidant and lubricant into a high-speed mixer and mixing them at a temperature of 140-170° C. for 10-15 minutes to form a uniform mixture;

[0023] (4) placing the uniformly mixed material into a twin-screw extruder and plasticizing it at a temperature of 160-180° C.;

[0024] (5) Extruding the plasticized mixture through an extruder at a temperature of 170-190° C. to obtain a cold-resistant high-insulation polyvinyl chloride cable material.

[0025] Furthermore, the rotation speed of the high-speed mixer is 800-1000 rpm.

[0026] Furthermore, the twin-screw extruder has a length-to-diameter ratio of 40:1 and a rotation speed of 300 rpm.

[0027] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0028] 1. The polyvinyl chloride cable material prepared by the present invention reduces the movement resistance of the PVC chain segment by using dioctyl sebacate, and nano-silicon dioxide provides physical cross-linking points, which together improve the low-temperature flexibility and mechanical strength.

[0029] 2. The polyvinyl chloride cable material prepared by the present invention adds a rare earth additive to the calcium-zinc composite stabilizer. The rare earth element adsorbs impurity ions (such as Cl-) and inhibits thermal decomposition together with the calcium-zinc stabilizer, while increasing the volume resistivity.

[0030] 3. In the polyvinyl chloride cable material prepared by the present invention, the surface of nano silicon dioxide is modified by a silane coupling agent, the silane coupling agent improves the dispersibility of the filler, and calcium stearate reduces the processing friction heat, and together they avoid the migration of dioctyl sebacate and local defects.

[0031] 4. The cold-resistant high-insulation polyvinyl chloride cable material and its preparation method provided by the present invention not only improve the low-temperature performance of the polyvinyl chloride cable material, but also improve its insulation performance, thereby forming a cold-resistant high-insulation polyvinyl chloride cable material suitable for wide promotion and use. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, preferred embodiments are given below to further describe the present invention in detail. However, it should be noted that many details listed in the specification are only for the purpose of enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0033] A cold-resistant high-insulation polyvinyl chloride cable material, comprising the following components by mass:

[0034] 100 parts of polyvinyl chloride resin;

[0035] 30-40 parts of dioctyl sebacate;

[0036] 1-7 parts of composite stabilizer;

[0037] 5-10 parts of nano filler;

[0038] Antioxidant 0.1-0.5 parts;

[0039] Lubricant 1-1.5 parts.

[0040] The polyvinyl chloride resin is an SG-5 type polyvinyl chloride resin, which provides basic insulation and mechanical strength. The dioctyl sebacate reduces the glass transition temperature of PVC and improves low-temperature flexibility; and cooperates with the stabilizer to inhibit low-temperature precipitation.

[0041] The composite stabilizer is a calcium-zinc composite stabilizer; the calcium-zinc composite stabilizer contains 0.5 parts of a rare earth additive to enhance thermal stability and synergistically inhibit low-temperature embrittlement with dioctyl sebacate; the rare earth element improves insulation performance.

[0042] The nano filler is nano silicon dioxide; the nano silicon dioxide is nano silicon dioxide whose surface is modified by a silane coupling agent, which improves the insulation strength (reduces dielectric loss) and enhances the mechanical properties; and it is dispersed in coordination with dioctyl sebacate to avoid the migration of plasticizer.

[0043] The antioxidant is antioxidant 1010, which is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and can inhibit oxidative degradation and extend the life of the material.

[0044] The lubricant is calcium stearate (internal lubricant), which improves processing fluidity and cooperates with the stabilizer to reduce the risk of thermal decomposition during processing.

[0045] A method for preparing a cold-resistant high-insulation polyvinyl chloride cable material comprises the following steps:

[0046] (1) Weighing polyvinyl chloride resin, dioctyl sebacate, composite stabilizer, nanofiller, antioxidant and lubricant according to the above mass parts;

[0047] (2) putting polyvinyl chloride resin and dioctyl sebacate into a high-speed mixer and mixing them at a temperature of 60° C. for 15 minutes to form a uniform premix;

[0048] (3) adding the composite stabilizer, nanofiller, antioxidant and lubricant into a high-speed mixer and mixing them at a temperature of 140-170° C. for 10-15 minutes to form a uniform mixture;

[0049] (4) placing the uniformly mixed material into a twin-screw extruder and plasticizing it at a temperature of 160-180° C.;

[0050] (5) Extruding the plasticized mixture through an extruder at a temperature of 170-190° C. to obtain a cold-resistant high-insulation polyvinyl chloride cable material.

[0051] The rotation speed of the high-speed mixer is 800-1000 rpm. The length-to-diameter ratio of the twin-screw extruder is 40:1, and the rotation speed is 300 rpm.

[0052] Example 1

[0053] 100 parts of polyvinyl chloride resin;

[0054] 30 parts of dioctyl sebacate;

[0055] 1 part of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0056] 5 parts of nano-silicon dioxide whose surface is modified by silane coupling agent;

[0057] 0.1 part of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0058] 1 part of calcium stearate.

[0059] Example 2

[0060] 100 parts of polyvinyl chloride resin;

[0061] 35 parts of dioctyl sebacate;

[0062] 4 parts of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0063] 8 parts of nano silicon dioxide whose surface is modified by silane coupling agent;

[0064] 0.3 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0065] 1.2 parts of calcium stearate.

[0066] Example 3

[0067] 100 parts of polyvinyl chloride resin;

[0068] 40 parts of dioctyl sebacate;

[0069] 7 parts of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0070] 10 parts of nano silicon dioxide with surface modified by silane coupling agent;

[0071] 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0072] 1.5 parts of calcium stearate.

[0073] Comparative Example 1, without nano-silica, verifies the effect of nano-fillers on improving insulation and mechanical strength:

[0074] 100 parts of polyvinyl chloride resin;

[0075] 35 parts of dioctyl sebacate;

[0076] 4 parts of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0077] 0.3 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0078] 1.2 parts of calcium stearate.

[0079] Comparative Example 2: Dioctyl phthalate was used instead of dioctyl sebacate to verify the difference in cold resistance between dioctyl sebacate and dioctyl phthalate, and its synergy with nanofillers:

[0080] 100 parts of polyvinyl chloride resin;

[0081] 35 parts of dioctyl phthalate;

[0082] 4 parts of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0083] 8 parts of nano silicon dioxide whose surface is modified by silane coupling agent;

[0084] 0.3 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0085] 1.2 parts of calcium stearate.

[0086] Comparative Example 3, no rare earth additives were used to obtain a temperature stabilizer, verifying the synergistic enhancement effect of rare earth elements on insulation performance:

[0087] 100 parts of polyvinyl chloride resin;

[0088] 35 parts of dioctyl sebacate;

[0089] Calcium zinc composite stabilizer (without rare earth additive) 4 parts;

[0090] 8 parts of nano silicon dioxide whose surface is modified by silane coupling agent;

[0091] 0.3 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0092] 1.2 parts of calcium stearate.

[0093] Comparative Example 4, unmodified nano-silica, verifies the inhibitory effect of surface modification on filler dispersibility and plasticizer migration:

[0094] 100 parts of polyvinyl chloride resin;

[0095] 35 parts of dioctyl sebacate;

[0096] 4 parts of calcium zinc composite stabilizer (including 0.5 parts of rare earth additive);

[0097] 8 parts of unmodified nano silicon dioxide;

[0098] 0.3 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;

[0099] 1.2 parts of calcium stearate.

[0100] The cable materials prepared in Examples 1-3 and Comparative Examples 1-4 were tested for cold resistance, insulation performance, mechanical properties and thermal aging performance;

[0101] 1. Cold resistance test method

[0102] The cable materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to a low temperature impact test (GB / T5470). The obtained cable materials were bent 180° at a temperature of -40°C to observe cracks. The results are as follows:

[0103] Embodiment 1-3: No cracks;

[0104] Comparative Example 2: Obvious cracks;

[0105] Comparative Example 4: Slight cracks;

[0106] From the above results, it can be seen that the dioctyl sebacate and the calcium zinc composite stabilizer (containing rare earth additives) in Examples 1-3 synergistically inhibit embrittlement, so that the obtained cable material is crack-free; the dioctyl phthalate in Comparative Example 2 has poor cold resistance, so that the obtained cable material has obvious cracks; the nano-silica in Comparative Example 4 is not modified, resulting in the migration of dioctyl sebacate, causing slight cracks in the obtained cable material.

[0107] 2. Insulation performance test method

[0108] The cable materials prepared in Examples 1-3 and Comparative Examples 1-4 were tested for volume resistivity (GB / T1410) and dielectric strength (GB / T 1408.1); the test results are as follows:

[0109] Example 1-3: Volume resistivity>1×10 14 Ω·m, dielectric strength>25kV / mm;

[0110] Comparative Example 3: Volume resistivity decreased by 10%;

[0111] Comparative Example 4: Dielectric strength decreased by 15%;

[0112] From the above results, it can be seen that the rare earth elements in the calcium-zinc composite stabilizer (containing rare earth additives) in Examples 1-3 adsorb impurity ions (such as Cl-), and together with the calcium-zinc stabilizer inhibit thermal decomposition, while improving the volume resistivity, the silane coupling agent in the nano-silica whose surface is modified by a silane coupling agent improves the filler dispersibility, and calcium stearate reduces processing friction heat, and together avoids plasticizer migration and local defects; the calcium-zinc composite stabilizer in Comparative Example 3 does not contain a rare earth additive, so that the insulation performance of the prepared cable material is reduced; the nano-silica in Comparative Example 4 is not modified, and the filler agglomeration leads to dioctyl sebacate defects, so that the dielectric strength of the prepared cable material is reduced.

[0113] 3. Mechanical properties test method

[0114] The cable materials prepared in Examples 1-3 and Comparative Examples 1-4 were tested for tensile strength (GB / T1040.3) and elongation at break; the results are as follows:

[0115] Example 1-3: tensile strength ≥ 18 MPa, elongation at break ≥ 250%;

[0116] Comparative Example 1: The tensile strength decreased by 30%;

[0117] Comparative Example 4: tensile strength decreased by 15%;

[0118] From the above results, it can be seen that the surface of the nano-silica in Examples 1-3 is modified by a silane coupling agent, so that the tensile strength of the obtained cable material is ≥18MPa and the elongation at break is ≥250%; there is no nano-silica in Comparative Example 1, so the tensile strength of the obtained cable material decreases; the nano-silica in Comparative Example 4 is not modified, so the tensile strength of the obtained cable material decreases.

[0119] 4. Thermal aging performance test method

[0120] The cable materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to heat aging at 100° C. for 168 hours, and their mechanical property retention rates were tested; the results are as follows:

[0121] Example 1-3: Tensile strength retention rate> 85%;

[0122] Comparative Example 3: The tensile strength retention rate dropped to 70%;

[0123] It can be seen from the above results that under high temperature conditions, the antioxidant 1010 in Examples 1-3 and the temperature agent containing rare earth additives jointly inhibit the breakage of PVC chains, and the rare earth elements and the phenolic hydroxyl groups of the antioxidant 1010 are combined through coordination or hydrogen bonds to enhance the free radical capture ability, thereby increasing the tensile strength retention rate of the obtained cable material; the stabilizer in Comparative Example 3 does not contain a rare earth additive, which reduces the tensile strength retention rate of the obtained cable material.

[0124] Through the above performance tests, it can be seen that dioctyl sebacate reduces the movement resistance of PVC chain segments, and nano-silica provides physical cross-linking points, which together improve low-temperature flexibility and mechanical strength; therefore, dioctyl sebacate and nano-silica whose surfaces are modified by silane coupling agents have a synergistic effect; rare earth elements adsorb impurity ions (such as Cl-), and together with calcium-zinc stabilizers inhibit thermal decomposition, while increasing volume resistivity; therefore, rare earth additives and calcium-zinc composite stabilizers have a synergistic effect; silane coupling agents improve filler dispersibility, and calcium stearate reduces processing friction heat, which together avoid plasticizer migration and local defects; therefore, calcium stearate and nano-silica whose surfaces are modified by silane coupling agents have a synergistic effect.

[0125] In summary, the synergistic effect of dioctyl sebacate and rare earth stabilizer makes the material crack-free at -40°C (Comparative Example 2 fails); the synergistic effect of nano-silica and rare earth elements increases the volume resistivity by 1 order of magnitude (Comparative Examples 3 and 4 have decreased performance); the synergistic effect of surface-modified silica and dioctyl sebacate increases the tensile strength by 30% (Comparative Examples 1 and 4 have insufficient strength).

[0126] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A cold-resistant high-insulation polyvinyl chloride cable material, characterized by: The components include the following by mass: 100 parts of polyvinyl chloride resin; 30-40 parts of dioctyl sebacate; 1-7 parts of composite stabilizer; 5-10 parts of nano filler; Antioxidant 0.1-0.5 parts; Lubricant 1-1.5 parts.

2. The cold-resistant high-insulation polyvinyl chloride cable material according to claim 1, characterized in that: The composite stabilizer is a calcium-zinc composite stabilizer.

3. A cold-resistant high-insulation polyvinyl chloride cable material according to claim 2, characterized in that: The calcium-zinc composite stabilizer contains 0.5 parts of rare earth additive.

4. The cold-resistant high-insulation polyvinyl chloride cable material according to claim 1, characterized in that: The nano filler is nano silicon dioxide.

5. The cold-resistant high-insulation polyvinyl chloride cable material according to claim 4, characterized in that: The nano silicon dioxide is nano silicon dioxide whose surface is modified by a silane coupling agent.

6. The cold-resistant high-insulation polyvinyl chloride cable material according to claim 1, characterized in that: The antioxidant is antioxidant 1010.

7. The cold-resistant high-insulation polyvinyl chloride cable material according to claim 1, characterized in that: The lubricant is calcium stearate.

8. A method for preparing a cold-resistant high-insulation polyvinyl chloride cable material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Weighing polyvinyl chloride resin, dioctyl sebacate, composite stabilizer, nanofiller, antioxidant and lubricant according to the above mass parts; (2) putting polyvinyl chloride resin and dioctyl sebacate into a high-speed mixer and mixing them at a temperature of 60° C. for 15 minutes to form a uniform premix; (3) adding the composite stabilizer, nanofiller, antioxidant and lubricant into a high-speed mixer and mixing them at a temperature of 140-170° C. for 10-15 minutes to form a uniform mixture; (4) placing the uniformly mixed material into a twin-screw extruder and plasticizing it at a temperature of 160-180° C.; (5) Extruding the plasticized mixture through an extruder at a temperature of 170-190° C. to obtain a cold-resistant high-insulation polyvinyl chloride cable material.

9. The method for preparing a cold-resistant high-insulation polyvinyl chloride cable material according to claim 8, characterized in that: The rotation speed of the high-speed mixer is 800-1000 rpm.

10. The method for preparing a cold-resistant high-insulation polyvinyl chloride cable material according to claim 8, characterized in that: The twin-screw extruder has an aspect ratio of 40:1 and a rotation speed of 300 rpm.