Hydrolysis resistant jacketing material and photovoltaic cable

Abstract

The application discloses a hydrolysis-resistant sheath material and a photovoltaic cable. The hydrolysis-resistant sheath material comprises the following raw materials in mass fractions: 60-80 parts of modified polyurethane elastomer, and 10-20 parts of fillers. The modified polyurethane is obtained through copolymerization of polyether polyol, diisocyanate, octamethylcyclotetrasiloxane, a chain extender and a catalyst. The cable comprises a sheath layer prepared from the sheath material. In the sheath material, the octamethylcyclotetrasiloxane is introduced into the polymerization chain of the modified polyurethane under the activation of diisocyanate and the catalysis of a catalyst, so that the polyurethane elastomer is modified from the polymerization chain. The hydrolysis resistance of the obtained modified polyurethane elastomer is significantly improved, the hydrolysis resistance of the sheath material is improved, and the service life of the photovoltaic cable in a humid or water-soaked environment is prolonged.

Description

Technical Field

[0001] This application relates to cables, and more particularly to a hydrolysis-resistant sheathing material and photovoltaic cables. Background Technology

[0002] With the widespread adoption and maturity of solar power generation technology, the solar photovoltaic grid-connected power generation industry has become one of the most watched emerging industries in the world today. As the solar photovoltaic grid-connected power generation industry develops, the increased land area required for its installation has led to the relocation of installation sites to water or even more challenging environments. Consequently, the photovoltaic cables used in solar photovoltaic grid-connected power generation often have to endure sun and rain, and may even float on water.

[0003] When the sheath of a photovoltaic cable is in prolonged contact with and immersed in water, it is prone to swelling and hydrolysis, which reduces the strength of the sheath and makes it susceptible to damage. This can expose the internal insulation layer or other components, affecting the service life and performance of the photovoltaic cable. Summary of the Invention

[0004] To extend the service life of photovoltaic cables in humid or water-immersed environments, a hydrolysis-resistant sheath material and a photovoltaic cable are provided.

[0005] The first inventive objective of this invention is achieved through the following technical solution:

[0006] A hydrolysis-resistant sheath material, comprising the following parts by weight of raw materials:

[0007] 60-80 parts of modified polyurethane elastomer,

[0008] The filler is 10-20 parts, and the modified polyurethane is obtained by copolymerization of polyether polyol, diisocyanate, octamethylcyclotetrasiloxane, chain extender, and catalytic copolymerization.

[0009] By adopting the above technical solution, octamethylcyclotetrasiloxane is incorporated into the polymer chain of modified polyurethane under the activation of diisocyanate and catalysis of catalyst, thereby modifying the polyurethane elastomer from the molecular polymer chain. The hydrolysis resistance of the resulting modified polyurethane elastomer is significantly improved, the hydrolysis resistance of the sheath material is improved, and the service life of photovoltaic cables in humid or water-immersed environments is extended.

[0010] Optional: The raw materials for the sheath material may also include 10 to 12 parts of POE.

[0011] By adopting the above technical solution, POE is added to adjust and improve the tensile strength and elongation at break of the sheath material, and to enhance the sheath material's impermeability, thereby improving the sheath material's hydrolysis resistance.

[0012] Optional: The raw materials for the sheath material also include 3 to 5 parts of POE-g-MAH.

[0013] By adopting the above technical solution, POE-g-MAH is used in combination with POE, and the compatibility of POE with modified polyurethane materials is improved, resulting in better improvement in tensile strength, elongation at break and hydrolysis resistance.

[0014] Optionally, the diisocyanate is diphenylmethane diisocyanate, and the polyether polyol is a compound obtained by combining polytetrahydrofuran ether diol and polyoxypropylene ether diol.

[0015] By adopting the above technical solution, the resulting sheath material exhibits superior hydrolysis resistance, tensile strength, and elongation at break.

[0016] Optionally, the mass ratio of the polyether polyol, diisocyanate, and octamethylcyclotetrasiloxane is controlled to be 10:4:0.8.

[0017] By adopting the above technical solution, the sheath material obtained at this ratio exhibits superior hydrolysis resistance, tensile strength, and elongation at break.

[0018] Optional: The raw materials for the sheath material also include 11 to 14 parts of basalt fiber.

[0019] By adopting the above technical solution, basalt fiber can enhance the toughness of the sheath material.

[0020] Optional: The basalt fiber is surface-hydrophobic modified.

[0021] By adopting the above technical solutions, basalt fiber can enhance the toughness of the sheath material. The hydrophobic modified basalt fiber can enhance the tensile strength and elongation at break of the sheath material, and also enhance the hydrolysis resistance of the sheath material.

[0022] The second objective of this invention is achieved through the following technical solution:

[0023] A photovoltaic cable includes an inner core, an insulation layer, and a sheath layer, wherein the sheath layer is made of the aforementioned hydrolysis-resistant sheath material.

[0024] In summary, this application has at least the following beneficial effects:

[0025] 1. By incorporating octamethylcyclotetrasiloxane into the polymer chain of modified polyurethane, the polyurethane elastomer is modified from the molecular polymer chain. The hydrolysis resistance of the resulting modified polyurethane elastomer is significantly improved, the hydrolysis resistance of the sheath material is improved, and the service life of photovoltaic cables in humid or water-immersed environments is extended.

[0026] 2. Basalt fiber can enhance the toughness of sheath materials. The unevenness of hydrophobically modified basalt fiber can enhance the tensile strength and elongation at break of the sheath material, as well as enhance the hydrolysis resistance of the sheath material. Detailed Implementation

[0027] raw material

[0028] Polytetrahydrofuran ether diol is PTMG 1000, a commercially available product of Mitsubishi Chemical Corporation of Japan.

[0029] Polyoxypropylene ether glycol is a commercially available product of Greenlink (Jining) Chemical Technology Co., Ltd., namely PPG 1000.

[0030] Diphenylmethylmethane diisocyanate, isophorone diisocyanate, octamethylcyclotetrasiloxane, 1,4-butanediol, sodium methoxide, hexadecyltrimethoxysilane, and dibutyltin dilaurate are all commercially available industrial-grade raw materials.

[0031] The basalt fibers are 10 mm long and 0.1 μm in diameter.

[0032] The filler is light calcium carbonate, a commercially available product.

[0033] The POE is Dow Chemical's ENGAGE POE 8150.

[0034] POE-g-MAH is Dow Chemical's GR216.

[0035] Preparation Example 1

[0036] A modified polyurethane elastomer, the raw materials of which include polyether polyol, diisocyanate, octamethylcyclotetrasiloxane, and chain extender.

[0037] The polyether polyol is a compound of polytetrahydrofuran ether diol and polyoxypropylene ether diol in a mass ratio of 1:0.6.

[0038] The diisocyanate is diphenylmethylmethane diisocyanate.

[0039] The chain extender is 1,4-butanediol.

[0040] The specific preparation process is as follows:

[0041] 9.6 kg of polyether polyol was divided into group A polyether polyol and group B polyether polyol, with a mass ratio of group A polyether polyol to group B polyether polyol of 6:4.

[0042] Group A polyether polyol was heated to 68℃, and 0.9 kg of diisocyanate was added. The mixture was stirred rapidly until it was mixed. When the temperature rise rate of the mixed material was less than 2℃ / min, the temperature was adjusted to 80±1℃ and the reaction was continued for 1 hour to obtain the transition reaction material. 0.92 kg of octamethylcyclotetrasiloxane and 0.01 kg of sodium methoxide were added to the transition reaction material. The temperature was controlled at 85±1℃ and the reaction was continued for 2 hours. Then, the mixture was vacuum treated to obtain the prepolymer.

[0043] The mixture was prepared by mixing group B polyether polyol, 4.08 kg chain extender, and 0.02 kg dibutyltin dilaurate.

[0044] The prepolymer and the mixture are heated to 60°C and then rapidly mixed at 1200 r / min to obtain a polyurethane elastomer by extrusion granulation.

[0045] Preparation Example 2

[0046] A modified polyurethane elastomer differs from Preparation Example 1 in that the amount of octamethylcyclotetrasiloxane used in the preparation process is 0.4 kg.

[0047] Preparation Example 3

[0048] A modified polyurethane elastomer differs from Preparation Example 1 in that the amount of octamethylcyclotetrasiloxane used in the preparation process is 1.35 kg.

[0049] Preparation Example 4

[0050] A modified polyurethane elastomer, which differs from Preparation Example 1 in that the diisocyanate is isophorone diisocyanate.

[0051] Preparation Example 5

[0052] A modified polyurethane elastomer, which differs from Preparation Example 1 in that the polyether polyol is a single polytetrahydrofuran ether diol.

[0053] Preparation Example 6

[0054] A polyurethane elastomer obtained by copolymerization of polyether polyol and diisocyanate.

[0055] The polyether polyol is a compound of polytetrahydrofuran ether diol and polyoxypropylene ether diol in a mass ratio of 1:0.6.

[0056] The diisocyanate is diphenylmethylmethane diisocyanate.

[0057] The specific preparation process is as follows:

[0058] 9.6 kg of polyether polyol was divided into group A polyether polyol and group B polyether polyol, with a mass ratio of group A polyether polyol to group B polyether polyol of 6:4.

[0059] Group A polyether polyol was heated to 68℃, and 0.9 kg of diisocyanate was added. The mixture was stirred rapidly until it was mixed. The temperature of the mixed material was raised at a rate of less than 2℃ / min. The temperature was adjusted to 80±1℃ and the reaction was continued for 3 hours. Then, the mixture was vacuumed to obtain the prepolymer.

[0060] The mixture was prepared by mixing group B polyether polyol, 4.08 kg chain extender, and 0.02 kg dibutyltin dilaurate.

[0061] The prepolymer and the mixture are heated to 60°C and then rapidly mixed at 1200 r / min to obtain a polyurethane elastomer by extrusion granulation.

[0062] Preparation Example 7

[0063] A hydrophobically modified basalt fiber is obtained by modifying basalt fiber with hexadecyltrimethoxysilane.

[0064] The specific modification process is as follows:

[0065] Basalt fiber, hexadecyltrimethoxysilane, and methanol were mixed evenly at a mass ratio of 100:12:4. After removing the methanol by evaporation, hydrophobic modified basalt fiber was obtained.

[0066] Example 1

[0067] A hydrolysis-resistant sheath material, the raw materials of which are modified polyurethane elastomer, filler, POE, POE-g-MAH and hydrophobic modified basalt fiber.

[0068] The modified polyurethane elastomer was prepared as described in Preparation Example 1.

[0069] The hydrophobically modified basalt fiber was prepared in Preparation Example 7.

[0070] The specific preparation process is as follows:

[0071] The mixed raw materials were obtained by uniformly mixing 75 kg of modified polyurethane elastomer, 17 kg of filler, 11.3 kg of POE, 4.5 kg of POE-g-MAH and 12 kg of hydrophobic modified basalt fiber.

[0072] The mixed raw materials are fed into a screw extruder for melting and mixing, and then extruded into a coating machine to coat the cable.

[0073] To prepare a test sample, the mixed raw materials are fed into a screw extruder for melting and mixing, then injected into a sample mold. After cooling, the sample is obtained.

[0074] Example 2

[0075] A hydrolysis-resistant sheath material, which differs from Example 1 in that the modified polyurethane elastomer was prepared in Preparation Example 2.

[0076] Example 3

[0077] A hydrolysis-resistant sheath material, which differs from Example 1 in that the modified polyurethane elastomer was prepared in Preparation Example 3.

[0078] Example 4

[0079] A hydrolysis-resistant sheath material, which differs from Example 1 in that the modified polyurethane elastomer was prepared in Preparation Example 4.

[0080] Example 5

[0081] A hydrolysis-resistant sheath material, which differs from Example 1 in that the modified polyurethane elastomer was prepared in Preparation Example 5.

[0082] Example 6

[0083] A hydrolysis-resistant sheath material differs from Example 1 in that its raw materials are modified polyurethane elastomer, filler, and hydrophobic modified basalt fiber.

[0084] The specific preparation method is as follows:

[0085] The mixed raw material was obtained by uniformly mixing 75 kg of modified polyurethane elastomer, 17 kg of filler, 0.6 kg of antioxidant, 0.4 kg of UV stabilizer, and 12 kg of hydrophobic modified basalt fiber.

[0086] The mixed raw materials are fed into a screw extruder for melting and mixing, and then extruded into a coating machine to coat the cable.

[0087] To prepare a test sample, the mixed raw materials are fed into a screw extruder for melting and mixing, then injected into a sample mold. After cooling, the sample is obtained.

[0088] Example 7

[0089] A hydrolysis-resistant sheath material differs from Example 1 in that its raw materials are modified polyurethane elastomer, filler, POE and hydrophobic modified basalt fiber.

[0090] The specific preparation method is as follows:

[0091] The mixed raw material was obtained by uniformly mixing 75 kg of modified polyurethane elastomer, 17 kg of filler, 0.6 kg of antioxidant, 0.4 kg of UV stabilizer, 11.3 kg of POE, and 12 kg of hydrophobic modified basalt fiber.

[0092] The mixed raw materials are fed into a screw extruder for melting and mixing, and then extruded into a coating machine to coat the cable.

[0093] To prepare a test sample, the mixed raw materials are fed into a screw extruder for melting and mixing, then injected into a sample mold. After cooling, the sample is obtained.

[0094] Example 8

[0095] A hydrolysis-resistant sheath material differs from Example 1 in that its raw materials are modified polyurethane elastomer, filler, POE, and POE-g-MAH.

[0096] The specific preparation method is as follows:

[0097] The modified polyurethane elastomer, 17 kg filler, 0.6 kg antioxidant, 0.4 kg UV stabilizer, 11.3 kg POE, and 4.5 kg POE-g-MAH were mixed evenly to obtain the mixed raw material.

[0098] The mixed raw materials are fed into a screw extruder for melting and mixing, and then extruded into a coating machine to coat the cable.

[0099] To prepare a test sample, the mixed raw materials are fed into a screw extruder for melting and mixing, then injected into a sample mold. After cooling, the sample is obtained.

[0100] Example 9

[0101] A hydrolysis-resistant sheath material differs from Example 1 in that its raw materials are modified polyurethane elastomer, filler, POE, POE-g-MAH and basalt fiber.

[0102] The specific preparation method is as follows:

[0103] The mixed raw material was obtained by uniformly mixing 75 kg of modified polyurethane elastomer, 17 kg of filler, 0.6 kg of antioxidant, 0.4 kg of UV stabilizer, 11.3 kg of POE, 4.5 kg of POE-g-MAH, and 12 kg of basalt fiber.

[0104] The mixed raw materials are fed into a screw extruder for melting and mixing, and then extruded into a coating machine to coat the cable.

[0105] To prepare a test sample, the mixed raw materials are fed into a screw extruder for melting and mixing, then injected into a sample mold. After cooling, the sample is obtained.

[0106] Example 10

[0107] A hydrolysis-resistant sheath material differs from Example 1 in the amount of raw materials used, specifically: 60 kg of modified polyurethane elastomer, 10 kg of filler, 11.3 kg of POE, 4.5 kg of POE-g-MAH, and 12 kg of hydrophobic modified basalt fiber.

[0108] Example 11

[0109] A hydrolysis-resistant sheath material differs from Example 1 in the amount of raw materials used, specifically: 80 kg of modified polyurethane elastomer, 20 kg of filler, 12 kg of POE, 5 kg of POE-g-MAH and 14 kg of hydrophobic modified basalt fiber.

[0110] Comparative Example 1

[0111] A sheath material, which differs from Example 1 in that it uses an equal mass of the polyurethane elastomer prepared in Preparation Example 6 instead of the modified polyurethane elastomer prepared in Preparation Example 1.

[0112] The tensile strength, elongation at break, and performance change rate after simulated hydrolysis were tested for Examples 1-11 and Comparative Example 1.

[0113] Tensile strength testing was conducted according to ASTM-D412.

[0114] Elongation at break was tested according to ASTM-D412.

[0115] The performance retention rate after simulated hydrolysis was tested according to ASTM-D412. The tensile strength and elongation at break were prepared and immersed in deionized water at 70°C for 168 hours. After immersion, the tensile strength and elongation at break after simulated hydrolysis were tested according to ASTM-D412, and the retention rate of tensile strength and elongation at break were calculated.

[0116] Tensile strength retention rate = (Tensile strength after simulated hydrolysis / Tensile strength) × 100%.

[0117] Elongation at break retention rate = Elongation at break after simulated hydrolysis / Elongation at break × 100%.

[0118] The test results are shown in Table 1.

[0119] Table 1. Detection results of Examples 1-11 and Comparative Example 1

[0120]

[0121]

[0122] Based on Table 1, comparing Example 1 and Comparative Example 1, it can be seen that the tensile strength and elongation at break of Example 1 are better than those of Comparative Example 1. Furthermore, after simulated hydrolysis, the retention rate of tensile strength and elongation at break of Example 1 are significantly better than those of Comparative Example 1.

[0123] The sheath material of Example 1 has superior hydrolysis resistance compared to the sheath material of Comparative Example 1.

[0124] In Example 1, a catalyst and octamethylcyclotetrasiloxane were added to the sheath material during the polymerization of polyurethane elastomer. Under the activation of diisocyanate, octamethylcyclotetrasiloxane was ring-opened and incorporated into the polymer chain of the modified polyurethane, thereby modifying the polyurethane elastomer from the molecular polymerization chain. The hydrolysis resistance of the resulting modified polyurethane elastomer was significantly improved, and the hydrolysis resistance of the sheath material was improved, thus extending the service life of the photovoltaic cable in humid or water-immersed environments.

[0125] In conjunction with Examples 1-3, the addition of octamethylcyclotetrasiloxane to the polymer chain of the modified polyurethane enhances the hydrolysis resistance of the modified polyurethane elastomer, but also affects the tensile strength and tensile breaking rate of the modified polyurethane elastomer. Comparing the test results of Examples 1-3, it can be seen that the tensile strength retention rate and elongation at break retention rate of Examples 1 and 3 are better than those of Example 2. Furthermore, the tensile strength and elongation at break of Example 1 are the best among Examples 1-3. Therefore, it can be concluded that when octamethylcyclotetrasiloxane is added to the polymer chain of the modified polyurethane, the tensile strength and elongation at break of the sheath material first increase and then decrease with increasing addition amount. Therefore, in this application, a mass ratio of polyether polyol, diisocyanate, and octamethylcyclotetrasiloxane of 10:4:0.8 is preferred for the modified polyurethane elastomer.

[0126] Comparing Examples 1 and 4-5, it can be seen that the polyether polyol used in Example 4 is different from that in Example 1, and the diisocyanate used in Example 5 is different from that in Example 1. In the test results, the tensile strength and elongation at break of Example 1 are greater than those of Examples 4-5, and the retention rates of tensile strength and elongation at break of Example 1 are also greater than those of Examples 4-5. Therefore, it can be concluded that in this application, the polyether polyol is better when it is a blend of polytetrahydrofuran ether diol and polyoxypropylene ether diol, and the diisocyanate is better when it is diphenylmethane diisocyanate.

[0127] Comparing Examples 1 and 6-7, it can be seen that the raw materials in Example 1 included POE and POE-g-MAH, the raw materials in Example 6 did not include POE and POE-g-MAH, and the raw materials in Example 7 only included POE without POE-g-MAH. In the test results, the tensile strength and elongation at break of Example 7 were greater than those of Example 6, and the retention rates of tensile strength and elongation at break of Example 7 were greater than those of Example 6. The tensile strength and elongation at break of Example 1 were greater than those of Example 7, and the retention rates of tensile strength and elongation at break of Example 1 were greater than those of Example 7. Therefore, the addition of POE to the sheath material of this application can enhance the hydrolysis resistance of the sheath material. Furthermore, the addition of POE-g-MAH on the basis of POE can improve the compatibility of POE in the modified polyurethane elastomer, making the POE mix more thoroughly, and further improving the strength and hydrolysis resistance of the sheath material.

[0128] Comparing Examples 1 and 8-9, Example 1 included the hydrophobic modified basalt fiber prepared in Example 7 in its raw materials, Example 8 did not include either unmodified basalt fiber or hydrophobic modified basalt fiber in its raw materials, and Example 9 included unmodified basalt fiber in its raw materials. The test results showed that the tensile strength of Example 9 was significantly greater than that of Example 8, and the elongation at break of Example 9 was greater than that of Example 8. Therefore, adding basalt fiber to the sheath material can improve the tensile properties of the sheath material.

[0129] Meanwhile, the tensile strength and elongation at break of Example 1 are significantly greater than those of Example 9. Furthermore, the improvement in tensile strength retention rate and elongation at break rate of Example 1 compared to Example 9 is significantly better than the improvement in tensile strength retention rate and elongation at break rate of Example 9 compared to Example 8. Therefore, hydrophobic modification of the basalt fiber added to the sheath material can further improve the tensile properties of the sheath material and also significantly improve its hydrolysis resistance.

[0130] In addition to Example 1, this application also includes other superior examples discovered during the research process, such as Examples 10 and 11. The tensile strength and elongation at break of Examples 10 and 11 were superior to those of Comparative Example 1 in the test results. Furthermore, after simulated hydrolysis, the tensile strength retention rate and elongation at break retention rate of Examples 10 and 11 were significantly better than those of Comparative Example 1. The sheath material of Examples 10 and 11 exhibits superior hydrolysis resistance compared to the sheath material of Comparative Example 1.

[0131] Example 12

[0132] A photovoltaic cable comprises, from the outside in, a sheath layer, an insulation layer, and an inner core. The sheath layer is made of a sheath material, which is one of the materials described in Examples 1 to 11.

[0133] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection claimed in this application.

Claims

1. A hydrolysis-resistant sheath material, characterized in that, The raw materials include the following parts by weight: 60-80 parts of modified polyurethane elastomer, 10-20 parts of filler POE 10-12 copies, POE-g-MAH 3~5 parts, The modified polyurethane elastomer is obtained by copolymerization of polyether polyol, diisocyanate, octamethylcyclotetrasiloxane, chain extender, and catalytic copolymerization. Modified polyurethane elastomers, whose raw materials include polyether polyols, diisocyanates, octamethylcyclotetrasiloxane, and chain extenders; The polyether polyol is a compound of polytetrahydrofuran ether diol and polyoxypropylene ether diol in a mass ratio of 1:0.6; The diisocyanate is diphenylmethylmethane diisocyanate; The chain extender is 1,4-butanediol; The preparation process of modified polyurethane elastomer is as follows: 9.6 kg of polyether polyol was divided into group A polyether polyol and group B polyether polyol, with a mass ratio of group A polyether polyol to group B polyether polyol of 6:

4. Heat the polyether polyol of group A to 68℃, add 0.9 kg of diisocyanate, and stir rapidly to mix it. When the temperature of the mixed material rises at a rate of less than 2℃ / min, adjust the temperature to 80±1℃ and continue the reaction for 1 hour to obtain the transition reaction material. Add 0.92 kg of octamethylcyclotetrasiloxane and 0.01 kg of sodium methoxide to the transition reaction material, control the temperature at 85±1℃, continue the reaction for 2 h, and then vacuum process to obtain the prepolymer. The mixture was prepared by mixing group B polyether polyol, 4.08 kg chain extender, and 0.02 kg dibutyltin dilaurate. The prepolymer and the mixture are heated to 60°C and then rapidly mixed at 1200 r / min to obtain a polyurethane elastomer by extrusion granulation.

2. The hydrolysis-resistant sheath material according to claim 1, characterized in that, The raw materials for the sheath also include 11 to 14 parts of basalt fiber.

3. The hydrolysis-resistant sheath material according to claim 2, characterized in that, The basalt fibers are modified to be hydrophobic on the surface.

4. A photovoltaic cable, characterized in that, It includes an inner core, an insulating layer, and a sheath layer, wherein the sheath layer is made of the hydrolysis-resistant sheath material according to any one of claims 1 to 3.

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