An environmentally friendly water-blocking photovoltaic cable and its processing technology

Abstract

The present invention relates to the technical field of cables, and particularly to an environmentally friendly water-blocking photovoltaic cable and its processing technology. The present invention includes the following steps: Step S1: Mix modified attapulgite, polypropylene, compatibilizer, and lubricant evenly, and melt and extrude to obtain a water-blocking layer; Step S2: Mix modified attapulgite, terminal epoxy polydimethylsiloxane, water-based epoxy resin, and curing agent evenly to obtain a protective coating; Step S3: Wrap the water-blocking layer, shielding layer, and water-blocking layer on the outer surface of the wire core in sequence, coat the protective coating on the surface of the water-blocking layer, and after curing, obtain a protective layer sleeve, thereby manufacturing an environmentally friendly water-blocking photovoltaic cable, which also has excellent flame retardant properties.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and specifically to an environmentally friendly water-blocking photovoltaic cable and its processing technology. Background Art

[0002] With the increasing attention to environmental issues, the environmentally friendly material polypropylene has gradually become a research hotspot in cable insulation. Polypropylene has the advantages of low cost, good heat resistance, and plasticization and reuse. However, the flammability of polypropylene limits its application in some cases.

[0003] In addition, an important problem faced by photovoltaic cables during use is water intrusion. The infiltration of water not only leads to a decline in the insulation performance of the cable, but may also cause electrical faults such as short circuits, seriously affecting the safety and stability of the photovoltaic system. Currently, most traditional waterproof agents on the market use fluorine-containing compounds. Although these materials have good waterproof performance, they have significant deficiencies in environmental friendliness and pose a potential threat to the ecological environment.

[0004] Therefore, we propose an environmentally friendly water-blocking photovoltaic cable and its processing technology. Summary of the Invention

[0005] The purpose of the present invention is to provide an environmentally friendly water-blocking photovoltaic cable and its processing technology to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A processing technology for an environmentally friendly water-blocking photovoltaic cable includes the following steps:

[0008] Step S1: Mix modified attapulgite, polypropylene, compatibilizer, and lubricant evenly, and melt and extrude to obtain a water-blocking layer;

[0009] Step S2: Mix modified attapulgite, terminal epoxy polydimethylsiloxane, waterborne epoxy resin, and curing agent evenly to obtain a protective coating;

[0010] Step S3: Wrap the water-blocking layer, shielding layer, and water-blocking layer on the outer surface of the wire core in sequence, coat the protective coating on the surface of the water-blocking layer, and after curing, obtain a protective layer sleeve to produce an environmentally friendly water-blocking photovoltaic cable.

[0011] Further, the water-blocking layer is composed of the following components in parts by weight: 50 - 60 parts of polypropylene, 10 - 20 parts of modified attapulgite, 1 - 3 parts of compatibilizer, and 0.5 - 1.0 part of lubricant.

[0012] Further, the compatibilizer is one of polypropylene grafted maleic anhydride and maleic anhydride grafted ethylene-octene copolymer.

[0013] Further, the lubricant is PP wax.

[0014] Further, the protective coating is composed of the following components in parts by weight: 5 - 10 parts of modified attapulgite, 3 - 8 parts of terminal epoxy polydimethylsiloxane, 40 - 50 parts of waterborne epoxy resin, and 8 - 12 parts of curing agent.

[0015] Further, the preparation method of the modified attapulgite is as follows:

[0016] Step (1): Ultrasonically disperse attapulgite in a mixed solution of ammonia water and propylene glycol methyl ether, add tetraethyl orthosilicate, hexadecyltrimethoxysilane, and γ - methacryloxypropyltrimethoxysilane, react at 55 - 65 °C for 2 - 4 h, and after filtration, washing, and drying, obtain attapulgite with double bonds;

[0017] Step (2): Under nitrogen protection, uniformly mix a mercapto - containing flame retardant and octadecanethiol to obtain a mixture; uniformly mix the attapulgite with double bonds, the mixture, and a photoinitiator, and after ultraviolet light irradiation, obtain modified attapulgite.

[0018] In the above technical solution, using attapulgite (ATP), tetraethyl orthosilicate (TEOS), hexadecyltrimethoxysilane (HDTMS), and γ - methacryloxypropyltrimethoxysilane (MPTMS) as the main raw materials, attapulgite with double bonds is prepared by the Stober method; then, through the thiol - ene click reaction of the attapulgite with double bonds with a mercapto - containing flame retardant and octadecanethiol, modified attapulgite is obtained.

[0019] Further, in the step (1), the attapulgite with double bonds is composed of the following components in parts by weight: 15 - 25 parts of attapulgite, 20 - 40 parts of ammonia water, 80 - 100 parts of propylene glycol methyl ether, 15 - 30 parts of tetraethyl orthosilicate, 5 - 10 parts of hexadecyltrimethoxysilane, and 8 - 12 parts of γ - methacryloxypropyltrimethoxysilane.

[0020] Further, in the step (2), the mass ratio of the mercapto - containing flame retardant to octadecanethiol is 1:(0.5 - 1.0).

[0021] Further, in the step (2), the mass ratio of the attapulgite with double bonds, the mixture, and the photoinitiator is 1:(1 - 3):(0.03 - 0.10).

[0022] Further, the photoinitiator is 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone

[0023] Further, the process conditions for the ultraviolet light irradiation are as follows: the irradiation wavelength is 360 - 400 nm, the irradiation time is 0.5 - 2.0 h, and the irradiation intensity is 25 - 35 mW / cm 2 .

[0024] Further, the preparation method of the mercapto - containing flame retardant is as follows:

[0025] Step A: Mix 1,5 - diamino naphthalene, 3 - aminopropyltriethoxysilane, and ethanol uniformly, add the mixed solution of terephthalaldehyde and ethanol, and react at 60 - 70 °C for 4 - 6 h to obtain an amino - containing compound;

[0026] Step B: Under nitrogen protection, mix L - cysteine, 1 - (3 - dimethylaminopropyl) - 3 - ethylcarbodiimide hydrochloride, and 1 - hydroxybenzotriazole uniformly, react for 2 - 3 h, dropwise add the mixed solution of the amino - containing compound and DMF, finish dropping in 30 - 50 min, and react at 30 - 40 °C for 6 - 8 h. After filtration, washing, and drying, an intermediate is obtained;

[0027] Step C: Under nitrogen protection, mix the intermediate, DOPO, and ethanol uniformly, reflux and react at 70 - 80 °C for 10 - 12 h, cool to room temperature, and after filtration, washing, and drying, a mercapto - containing flame retardant is obtained.

[0028] In the above - mentioned technical solution, the amino groups in 1,5 - diamino naphthalene and 3 - aminopropyltriethoxysilane respectively react with the aldehyde groups at both ends of terephthalaldehyde through Schiff base reaction to obtain an amino - containing compound containing C=N bonds; then, the carboxyl group in L - cysteine reacts with the amino group in the amino - containing compound through condensation reaction to introduce mercapto and amino groups to obtain an intermediate; finally, the C=N bond of the intermediate reacts with the P - H bond in DOPO to obtain a flame retardant containing N, Si, S, and P elements, which has excellent flame - retardant effect and reactivity.

[0029] Further, in the above - mentioned Step A, the mass ratio of 1,5 - diamino naphthalene, 3 - aminopropyltriethoxysilane, ethanol, and terephthalaldehyde is 1:(1.4 - 1.6):(8 - 10):(0.8 - 0.9).

[0030] Further, in the above - mentioned Step A, the mass ratio of terephthalaldehyde and ethanol is 1:(2 - 4).

[0031] Further, in the above - mentioned Step B, the mass ratio of L - cysteine, 1 - (3 - dimethylaminopropyl) - 3 - ethylcarbodiimide hydrochloride, and 1 - hydroxybenzotriazole is 1:(0.1 - 0.2):(0.08 - 0.10).

[0032] Further, in the step B, the mass of the amino group-containing compound is 2-2.5 times that of L-cysteine, and the mass ratio of the amino group-containing compound to DMF is 1:(2-4).

[0033] Further, in the step C, the mass ratio of the intermediate, DOPO and ethanol is 1:(1-3):(8-10).

[0034] Further, the core is stranded by 3-6 tinned copper wire conductors.

[0035] Further, the shielding layer is a copper strip with a thickness of 2-5 mm.

[0036] Further, the coating thickness of the protective coating is 100-200 μm.

[0037] Further, the thickness of the water blocking layer is 3-5 mm.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. An environmentally friendly water-blocking photovoltaic cable and its processing technology of the present invention use 1,5-diaminonaphthalene, 3-aminopropyltriethoxysilane and terephthalaldehyde as raw materials to obtain an amino group-containing compound. The rigid compound 1,5-diaminonaphthalene with a naphthalene ring is introduced to improve its heat resistance. Then, a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) / 1-hydroxybenzotriazole (HOBt) dehydration system is used to promote the condensation reaction between the carboxyl group in L-cysteine and the amino group in the amino group-containing compound, introducing a mercapto group and an amino group to obtain an intermediate. Finally, the C=N bond of the intermediate reacts with the P-H bond in DOPO to obtain a mercapto group-containing flame retardant containing N, Si, S, and P elements, forming a multi-element synergistic effect, which can release smoke and flame-retardant gases that inhibit combustion at high temperatures and improve the flame retardant effect of the material.

[0040] 2. An environmentally friendly water-blocking photovoltaic cable and its processing technology of the present invention graft double bonds and hydrophobic long carbon chains on the surface of attapulgite to obtain attapulgite containing double bonds. The mercapto group-containing flame retardant and octadecanethiol are compounded, and further undergo a thiol-ene click reaction with the attapulgite containing double bonds. The reaction process is environmentally friendly, not only improving the flame retardant performance of the material, but also endowing it with excellent hydrophobic properties. Further introducing the compounding of terminal epoxy polydimethylsiloxane, the molecular structure of terminal epoxy polydimethylsiloxane contains a silicon-oxygen chain and an epoxy group, which helps to improve the hydrophobic properties of the material, effectively improving the compatibility between the modified attapulgite and epoxy resin, improving the adhesion and durability of the coating, and finally obtaining a durable superhydrophobic protective layer. Specific embodiments

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] In this embodiment, attapulgite: the particle size is 2000 mesh, sourced from Tuoyi New Materials (Guangzhou) Co., Ltd.; polypropylene: the grade is Shanghai Petrochemical R700M; tinned copper wire conductor: the diameter is 0.5 mm, sourced from Shenzhen Hongguansheng Technology Co., Ltd.; PP wax: the grade is Clariant Licocene PP2502; compatibilizer: polypropylene grafted maleic anhydride, the grade is Exxon PO1020 from the United States; terminal epoxy polydimethylsiloxane: the grade is 276-6K, sourced from Jiaxing United Chemical Co., Ltd.; shielding layer: copper tape, the material is T2, sourced from Shanghai Xingnuo Industry Co., Ltd.; waterborne epoxy resin: the grade is Dow DER-916 from the United States.

[0043] In the following examples and comparative examples, 1 part is equal to 10 g.

[0044] Example 1: A processing technology for an environmentally friendly water-blocking photovoltaic cable, including the following processes:

[0045] Step S1: Mix 10 parts of modified attapulgite, 50 parts of polypropylene, 1 part of compatibilizer, and 0.5 part of PP wax evenly, and melt-extrude to obtain a water-blocking layer.

[0046] Step S2: Mix 5 parts of modified attapulgite, 3 parts of terminal epoxy polydimethylsiloxane, 40 parts of waterborne epoxy resin, and 8 parts of curing agent evenly to obtain a protective coating.

[0047] Step S3: Wrap a water-blocking layer, a shielding layer, and a water-blocking layer on the outer surface of the wire core (stranded by 5 tinned copper wire conductors) in sequence, coat the protective coating on the surface of the water-blocking layer, and after curing, obtain a protective layer sleeve, thus manufacturing an environmentally friendly water-blocking photovoltaic cable.

[0048] The preparation method of the modified attapulgite is as follows:

[0049] Step (1): Ultrasonically disperse 15 parts of attapulgite in a mixed solution of 20 parts of ammonia water and 80 parts of propylene glycol monomethyl ether, add 15 parts of tetraethyl orthosilicate, 5 parts of hexadecyltrimethoxysilane, and 8 parts of γ-methacryloxypropyltrimethoxysilane, react at 55 °C for 2 h, and after filtration, washing, and drying, obtain double-bond-containing attapulgite.

[0050] Step (2): Under nitrogen protection, 10 parts of mercapto-containing flame retardant and 5 parts of octadecanethiol are mixed evenly to obtain a mixture; 15 parts of double bond-containing attapulgite, 15 parts of the mixture and 0.45 parts of photoinitiator are mixed evenly, and after ultraviolet irradiation (irradiation wavelength 360 nm, irradiation time 0.5 h, irradiation intensity 25 mW / cm 2 ), the modified attapulgite is obtained;

[0051] The preparation method of the mercapto-containing flame retardant is as follows:

[0052] Step A: 10 parts of 1,5-diaminonaphthalene, 14 parts of 3-aminopropyltriethoxysilane and 80 parts of ethanol are mixed evenly, and a mixed solution of 8 parts of terephthalaldehyde and 16 parts of ethanol is added, and the reaction is carried out at 60 °C for 4 h to obtain an amino-containing compound;

[0053] Step B: Under nitrogen protection, 5 parts of L-cysteine, 0.5 part of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.4 part of 1-hydroxybenzotriazole are mixed evenly, and the reaction is carried out for 2 h. A mixed solution of 10 parts of the amino-containing compound and 20 parts of DMF is added dropwise, and the addition is completed in 30 min. The reaction is carried out at 30 °C for 6 h. After filtration, washing and drying, an intermediate is obtained;

[0054] Step C: Under nitrogen protection, 10 parts of the intermediate, 10 parts of DOPO and 80 parts of ethanol are mixed evenly, and the reaction is refluxed at 70 °C for 10 h, cooled to room temperature, and after filtration, washing and drying, the mercapto-containing flame retardant is obtained.

[0055] Example 2: A processing technology of an environmentally friendly water-blocking photovoltaic cable, including the following processes:

[0056] Step S1: 15 parts of modified attapulgite, 55 parts of polypropylene, 2 parts of compatibilizer, and 0.8 part of PP wax are mixed evenly and melt-extruded to obtain a water-blocking layer;

[0057] Step S2: 8 parts of modified attapulgite, 5 parts of terminal epoxy polydimethylsiloxane, 45 parts of waterborne epoxy resin and 10 parts of curing agent are mixed evenly to obtain a protective coating;

[0058] Step S3: The water-blocking layer, the shielding layer and the water-blocking layer are sequentially wrapped on the outer surface of the wire core (stranded by 5 tinned copper wire conductors), and the protective coating is coated on the surface of the water-blocking layer. After curing, a protective layer sleeve is obtained, and an environmentally friendly water-blocking photovoltaic cable is prepared;

[0059] The preparation method of the modified attapulgite is as follows:

[0060] Step (1): Ultrasonically disperse 23 parts of attapulgite in a mixed solution of 30 parts of ammonia water and 90 parts of propylene glycol methyl ether. Add 25 parts of tetraethyl orthosilicate, 8 parts of cetyltrimethoxysilane, and 10 parts of γ-methacryloxypropyltrimethoxysilane, and react at 60 °C for 3 h. After filtration, washing, and drying, attapulgite containing double bonds is obtained;

[0061] Step (2): Under nitrogen protection, uniformly mix 28 parts of a mercapto-containing flame retardant and 18 parts of octadecanethiol to obtain a mixture; uniformly mix 23 parts of attapulgite containing double bonds, 46 parts of the mixture, and 1 part of a photoinitiator, and irradiate with ultraviolet light (irradiation wavelength 380 nm, irradiation time 1 h, irradiation intensity 30 mW / cm 2 ), to obtain modified attapulgite;

[0062] The preparation method of the mercapto-containing flame retardant is as follows:

[0063] Step A: Uniformly mix 28 parts of 1,5-diaminonaphthalene, 42 parts of 3-aminopropyltriethoxysilane, and 250 parts of ethanol. Add a mixed solution of 24 parts of terephthalaldehyde and 72 parts of ethanol, and react at 65 °C for 5 h to obtain an amino-containing compound;

[0064] Step B: Under nitrogen protection, uniformly mix 11.2 parts of L-cysteine, 1.68 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1 part of 1-hydroxybenzotriazole, and react for 2.5 h. Dropwise add a mixed solution of 28 parts of the amino-containing compound and 84 parts of DMF, finish dropping in 40 min, and react at 35 °C for 7 h. After filtration, washing, and drying, an intermediate is obtained;

[0065] Step C: Under nitrogen protection, uniformly mix 28 parts of the intermediate, 56 parts of DOPO, and 250 parts of ethanol, reflux and react at 75 °C for 11 h, cool to room temperature, and after filtration, washing, and drying, a mercapto-containing flame retardant is obtained.

[0066] Example 3: A processing technology for an environmentally friendly water-blocking photovoltaic cable, including the following processes:

[0067] Step S1: Uniformly mix 20 parts of modified attapulgite, 60 parts of polypropylene, 3 parts of a compatibilizer, and 1.0 part of PP wax, and melt and extrude to obtain a water-blocking layer;

[0068] Step S2: Uniformly mix 10 parts of modified attapulgite, 8 parts of terminal epoxy polydimethylsiloxane, 50 parts of waterborne epoxy resin, and 12 parts of a curing agent to obtain a protective coating;

[0069] Step S3: Wrap a water-blocking layer, a shielding layer, and another water-blocking layer around the outer surface of the conductor (which is composed of 5 stranded tinned copper wires). Apply a protective coating on the surface of the water-blocking layer. After curing, a protective layer sleeve is obtained, and an environmentally friendly water-blocking photovoltaic cable is manufactured.

[0070] The preparation method of the modified attapulgite is as follows:

[0071] Step (1): Ultrasonically disperse 25 parts of attapulgite in a mixed solution of 40 parts of ammonia water and 100 parts of propylene glycol methyl ether. Add 30 parts of tetraethyl orthosilicate, 10 parts of hexadecyltrimethoxysilane, and 12 parts of γ-methacryloxypropyltrimethoxysilane. React at 65 °C for 4 h. After filtration, washing, and drying, attapulgite containing double bonds is obtained.

[0072] Step (2): Under nitrogen protection, uniformly mix 37.5 parts of a mercapto-containing flame retardant and 37.5 parts of octadecanethiol to obtain a mixture; uniformly mix 25 parts of attapulgite containing double bonds, 75 parts of the mixture, and 2.5 parts of a photoinitiator. After ultraviolet light irradiation (irradiation wavelength 400 nm, irradiation time 2.0 h, irradiation intensity 35 mW / cm 2 ), modified attapulgite is obtained.

[0073] The preparation method of the mercapto-containing flame retardant is as follows:

[0074] Step A: Uniformly mix 40 parts of 1,5-diaminonaphthalene, 64 parts of 3-aminopropyltriethoxysilane, and 400 parts of ethanol. Add a mixed solution of 36 parts of terephthalaldehyde and 144 parts of ethanol. React at 70 °C for 6 h to obtain an amino-containing compound.

[0075] Step B: Under nitrogen protection, uniformly mix 16 parts of L-cysteine, 3.2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1.6 parts of 1-hydroxybenzotriazole. React for 3 h. Dropwise add a mixed solution of 40 parts of the amino-containing compound and 160 parts of DMF over 50 min. React at 40 °C for 8 h. After filtration, washing, and drying, an intermediate is obtained.

[0076] Step C: Under nitrogen protection, uniformly mix 40 parts of the intermediate, 120 parts of DOPO, and 400 parts of ethanol. React under reflux at 80 °C for 12 h. Cool to room temperature. After filtration, washing, and drying, a mercapto-containing flame retardant is obtained.

[0077] Comparative Example 1: The processing technology of an environmentally friendly water-blocking photovoltaic cable includes the following processes:

[0078] Step S1: Uniformly mix 15 parts of attapulgite containing double bonds, 55 parts of polypropylene, 2 parts of a compatibilizer, and 0.8 part of PP wax, and melt-extrude to obtain a water-blocking layer.

[0079] Step S2: Mix 8 parts of double-bonded attapulgite, 5 parts of terminal epoxy polydimethylsiloxane, 45 parts of waterborne epoxy resin and 10 parts of curing agent evenly to obtain a protective coating;

[0080] Step S3: Wrap a water-blocking layer, a shielding layer, and a water-blocking layer on the outer surface of the core (stranded by 5 tinned copper wire conductors) in sequence. Coat the protective coating on the surface of the water-blocking layer. After curing, a protective layer sleeve is obtained, and an environmentally friendly water-blocking photovoltaic cable is prepared;

[0081] Compared with Example 2, in Comparative Example 1, the modified attapulgite is replaced with the same mass of double-bonded attapulgite, and other steps are the same as those in Example 2.

[0082] Comparative Example 2: A processing technology for an environmentally friendly water-blocking photovoltaic cable, including the following processes:

[0083] Step S1: Mix 15 parts of modified attapulgite, 55 parts of polypropylene, 2 parts of compatibilizer, and 0.8 part of PP wax evenly, and melt-extrude to obtain a water-blocking layer;

[0084] Step S2: Mix 8 parts of modified attapulgite, 45 parts of waterborne epoxy resin and 10 parts of curing agent evenly to obtain a protective coating;

[0085] Step S3: Wrap a water-blocking layer, a shielding layer, and a water-blocking layer on the outer surface of the core (stranded by 5 tinned copper wire conductors) in sequence. Coat the protective coating on the surface of the water-blocking layer. After curing, a protective layer sleeve is obtained, and an environmentally friendly water-blocking photovoltaic cable is prepared;

[0086] Compared with Example 2, the protective coating in Comparative Example 2 does not add terminal epoxy polydimethylsiloxane, and other steps are the same as those in Example 2.

[0087] Comparative Example 3: A processing technology for an environmentally friendly water-blocking photovoltaic cable, including the following processes:

[0088] The preparation method of the modified attapulgite is as follows:

[0089] Step (1): Ultrasonically disperse 23 parts of attapulgite in a mixed solution of 30 parts of ammonia water and 90 parts of propylene glycol methyl ether. Add 25 parts of tetraethyl orthosilicate, 8 parts of cetyltrimethoxysilane, and 10 parts of γ-methacryloxypropyltrimethoxysilane, and react at 60 °C for 3 h. After filtration, washing, and drying, double-bonded attapulgite is obtained;

[0090] Step (2): Under nitrogen protection, mix 28 parts of DOPO and 18 parts of octadecanethiol evenly to obtain a mixture; Mix 23 parts of double-bonded attapulgite, 46 parts of the mixture and 1 part of photoinitiator evenly, and irradiate with ultraviolet light (irradiation wavelength 380 nm, irradiation time 1 h, irradiation intensity 30 mW / cm2 ), obtaining modified attapulgite;

[0091] Compared with Example 2, in Comparative Example 3, the mercapto-containing flame retardant was replaced with the same mass of DOPO, and the other steps were the same as those in Example 2.

[0092] Experiment: Take the protective layer sleeves obtained in Examples 1-3 and Comparative Examples 1-3 to prepare specimens, and detect their properties respectively and record the test results:

[0093] Flammability: Test according to the vertical combustion test flame retardant grade in GB / T2408-2008, and the size of the specimen is 100mm in length × 50mm in width; Hydrophobicity: Measure the water contact angle using a contact angle tester, and the test liquid is a 4μL water droplet; Tensile strength: Determine the tensile strength with reference to GB / T 1040.3-2006 "Testing of Plastics - Tensile Properties", the size of the specimen is 150mm × 15mm × 1mm, and the tensile speed is 25mm / min.

[0094] The test results are as follows:

[0095] Flame retardant grade Water contact angle / ° Tensile strength / MPa Example 1 V-0 148.4 37.2 Example 2 V-0 149.2 37.5 Example 3 V-0 147.5 36.8 Comparative example 1 V-1 133.6 34.3 Comparative example 2 V-0 138.7 36.1 Comparative example 3 V-1 145.0 35.7

[0096] According to the data in the above table, the following conclusions can be clearly obtained:

[0097] 1. Compared with Examples 1-3, the flame retardant grade, water contact angle and tensile strength of the product obtained in Comparative Example 1 all decreased, indicating that compared with the attapulgite containing double bonds, the modified attapulgite prepared in the present invention has better flame retardant effect and hydrophobic performance, and introduces a rigid structure, thereby effectively improving the flame retardant performance and mechanical properties of the material; the water contact angle of the product obtained in Comparative Example 2 decreased to some extent, and it can be seen that the introduction of terminal epoxy polydimethylsiloxane in the present invention helps to improve the hydrophobic performance of the material.

[0098] 2. Compared with Examples 1-3, the flame retardant grade and tensile strength of the product obtained in Comparative Example 3 both decreased to some extent, indicating that compared with the same mass of DOPO, the mercapto-containing flame retardant prepared in the present invention has better flame retardant performance and compatibility, and can better improve the mechanical properties of the material.

[0099] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A processing technology for an environmentally friendly water-blocking photovoltaic cable, characterized in that: The steps include: Step S1: uniformly mixing modified attapulgite, polypropylene, a compatibilizer, and a lubricant, and melt-extruding the mixture to obtain a water-blocking layer; Step S2: uniformly mixing the modified attapulgite, the epoxy-terminated polydimethylsiloxane, the waterborne epoxy resin and the curing agent to obtain a protective coating; Step S3: sequentially wrapping a water-blocking layer, a shielding layer, and a water-blocking layer on the outer surface of the wire core, coating the surface of the water-blocking layer with a protective coating, and after curing, obtaining a protective layer sleeve, thereby obtaining an environmentally friendly water-blocking photovoltaic cable; The preparation method of the modified attapulgite is as follows: Step (1): ultrasonically disperse attapulgite in a mixed solution of ammonia water and propylene glycol methyl ether, add tetraethyl orthosilicate, hexadecyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane, react at 55-65° C. for 2-4 hours, and obtain attapulgite containing double bonds after filtering, washing, and drying; Step (2): under nitrogen protection, uniformly mixing a mercapto-containing flame retardant and octadecyl mercaptan to obtain a mixture; uniformly mixing attapulgite containing double bonds, the mixture and a photoinitiator, and irradiating the mixture with ultraviolet light to obtain modified attapulgite; The preparation method of the mercapto-containing flame retardant is as follows: Step A: 1,5-diaminonaphthalene, 3-aminopropyltriethoxysilane and ethanol are uniformly mixed, a mixed solution of terephthalaldehyde and ethanol is added, and the mixture is reacted at 60-70° C. for 4-6 hours to obtain an amino compound; Step B: Under nitrogen protection, L-cysteine, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1-hydroxybenzotriazole are mixed evenly, reacted for 2-3 hours, a mixed solution containing an amino compound and DMF is added dropwise, and the mixture is added dropwise for 30-50 minutes, and the mixture is reacted at 30-40° C. for 6-8 hours. After filtering, washing and drying, an intermediate is obtained; Step C: Under nitrogen protection, the intermediate, DOPO and ethanol are mixed evenly, refluxed at 70-80° C. for 10-12 hours, cooled to room temperature, filtered, washed and dried to obtain a thiol-containing flame retardant.

2. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: The water-blocking layer is composed of the following components in parts by weight: 50-60 parts of polypropylene, 10-20 parts of modified attapulgite, 1-3 parts of a volume extender, and 0.5-1.0 parts of a lubricant.

3. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: The protective coating is composed of the following components in parts by weight: 5-10 parts of modified attapulgite, 3-8 parts of epoxy-terminated polydimethylsiloxane, 40-50 parts of waterborne epoxy resin, and 8-12 parts of curing agent.

4. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: In the step (1), the double bond-containing attapulgite is composed of the following components in parts by weight: 15-25 parts of attapulgite, 20-40 parts of aqueous ammonia, 80-100 parts of propylene glycol methyl ether, 15-30 parts of tetraethyl orthosilicate, 5-10 parts of hexadecyltrimethoxysilane, and 8-12 parts of γ-methacryloxypropyltrimethoxysilane.

5. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: In the step C, the mass ratio of the intermediate, DOPO and ethanol is 1:(1-3):(8-10).

6. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: The wire core is formed by twisting 3 to 6 tinned copper wire conductors.

7. The processing technology of an environmentally friendly water-blocking photovoltaic cable according to claim 1 is characterized in that: The shielding layer is a copper tape.

8. An environmentally friendly water-blocking photovoltaic cable manufactured according to the processing technology described in any one of claims 1 to 7.