Polyurea repair coating for power distribution cable sheath below 35kV
By coating polyurea repair coatings with isocyanate and other components on the cable sheath, and using halogen-free flame retardant elements and triazine-type structures to form a crosslinking network, the problem of easy damage and fire in the cable sheath is solved, achieving high efficiency The flame retardant, UV resistance and hydrophobic effects extend the service life of the cable.
Patent Information
- Application Number
- CN202411157476.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2024-12-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the prior art, power cable sheath is prone to local damage, cracking, powdering and other problems during use, and is prone to catch fire in dry climates or special occasions, resulting in fire accidents, and the existing flame retardant effect is insufficient.
A polyurea repair coating with components such as isocyanate, polyether polyol, vinyl polydimethylsiloxane, etc., and the halogen-free flame retardant elements nitrogen, phosphorus, silicon and Triazine-like structures form hybrid crosslinking network structures, giving coatings high efficiency flame retardant, UV resistance and hydrophobicity.
The coating significantly improves the aging resistance, wear resistance, waterproof and flame retardant properties of the cable sheath, extends the service life of the cable, and reduces the occurrence of fire accidents.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coatings, and in particular relates to a polyurea repair coating for sheaths of distribution cables below 35 kV. Background Art
[0002] Power cables are cables used to transmit and distribute high-power electrical energy in the trunk lines of power systems. They are commonly used in urban underground power grids, lead-out lines of power stations, internal power supplies of industrial and mining enterprises, and underwater transmission lines across rivers and seas. With the rapid development of the power cable industry, the number of power cables continues to increase, and the overall technical level of the industry is greatly improving. However, during use, power cables often have problems such as local damage, cracking, and powdering of the cable sheath, making the cable unusable. In order to better protect and repair the cable, polyurea repair coating can be coated on the cable sheath to make the cable sheath more resistant to aging, wear and waterproof, so that it can continue to be used and reduce economic losses.
[0003] In addition, although the purpose of fire prevention and flame retardancy is achieved by adding a variety of flame retardants to the cable sheath material, the cable material is still prone to ignition and cause fires in areas with dry climates and certain special occasions. In order to better protect the cable, the polyurea repair coating of the cable sheath can be given a flame retardant effect to further enhance the flame retardant properties of the cable sheath, thereby reducing the occurrence of fire accidents. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a polyurea repair coating for the sheath of distribution cables below 35 kV.
[0005] The purpose of the present invention can be achieved by the following technical solutions: A polyurea repair coating for distribution cable sheaths below 35 kV comprises an A component and a B component.
[0006] Further, the component A comprises the following raw materials in parts by weight: 55-65 parts of isocyanate, 30-40 parts of polyether polyol, and 5-8 parts of vinyl polydimethylsiloxane; Furthermore, the B component comprises the following raw materials in parts by weight: 40-45 parts of amino polyether, 30-38 parts of chain extender, 12-15 parts of plasticizer, 10-15 parts of filler, and 3-6 parts of auxiliary agent.
[0007] Furthermore, the isocyanate is one or more of 3,3-dimethyl-4,4-dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.
[0008] Furthermore, the polyether polyol is one or both of polyether polyol 330N and polyether polyol 3050.
[0009] Furthermore, the amino polyether is diaminodiphenyl ether.
[0010] Furthermore, the chain extender is one or both of diethyltoluenediamine and isophoronediamine.
[0011] Furthermore, the plasticizer is one or more of diisononyl phthalate, dioctyl terephthalate, and dipropylene glycol dibenzoate.
[0012] Furthermore, the filler is one or more of nano calcium carbonate, nano titanium dioxide, nano silicon dioxide, kaolin and talc.
[0013] Furthermore, the auxiliary agent is prepared by the following steps: S1. Under nitrogen protection, 2-(perfluorohexyl)ethyl methacrylate, DBU (1,8-diazobisspiro[5.4.0]undec-7-ene) and chloroform were added to a three-necked flask, stirred evenly, and then a mixed solution of diethylaminomethanephosphonate and chloroform was slowly added. After the addition was completed, the temperature was raised to 60°C and the reaction was carried out for 48 hours. After the reaction was completed, the intermediate 1 was obtained by distillation under reduced pressure; the dosage ratio of 2-(perfluorohexyl)ethyl methacrylate, diethylaminomethanephosphonate, DBU and chloroform was 7.3 g:11.6 mL:1.3 mL:120 mL; Under the catalytic action of DBU, the molar ratio of diethylaminomethanephosphonate to 2-(perfluorohexyl)ethyl methacrylate is controlled to be 1.05-1.1:1, and diethylaminomethanephosphonate and 2-(perfluorohexyl)ethyl methacrylate undergo Michael addition reaction, and the reaction process is as follows:
[0014] S2, under nitrogen protection, add cyanuric chloride, intermediate 1 and xylene into a dry three-necked flask, stir until completely dissolved, then slowly add 20wt% sodium bicarbonate solution, control the temperature at 0-5°C to react for 8h after the addition is complete, add deionized water after shaking and stand for stratification after completion of the reaction, separate the aqueous phase and measure the pH until the pH of the aqueous phase is neutral, then take the organic phase and dry it with anhydrous magnesium sulfate, filter, and distill the filtrate under reduced pressure to obtain intermediate 2; the molar ratio of cyanuric chloride to intermediate 1 is 1.05-1.1:1; Under alkaline conditions, a -Cl of cyanuric chloride and -NH- of intermediate 1 undergo nucleophilic substitution reaction. The reaction process is as follows:
[0015] S3. In a dry brown three-necked flask under nitrogen protection, resorcinol, anhydrous aluminum chloride and DMSO (dimethyl sulfoxide) were added in sequence, and after stirring evenly, a mixed solution of intermediate 2 and DMSO was added, and then the mixture was heated to 115°C with stirring, and reacted at 115°C for 12 hours. After the reaction was completed, the reaction mixture was slowly poured into ice water, solids were precipitated, filtered, and then recrystallized with 80% methanol aqueous solution to obtain intermediate 3; the dosage ratio of intermediate 2, resorcinol, anhydrous aluminum chloride and DMSO was 22.4g:6mL:2.1g:180mL; The molar ratio of intermediate 2 to resorcinol is controlled to be 1:2.1-2.4, and intermediate 2 and resorcinol undergo Friedel-Crafts acylation reaction under the catalysis of anhydrous aluminum chloride. The reaction process is as follows:
[0016] S4, blow the dry three-necked flask with nitrogen for 30 minutes to drive away the air in the flask, then add intermediate 3 and DMSO, stir thoroughly until mixed, then slowly add KH540 (3-aminopropyltrimethoxysilane) under nitrogen protection, after the addition is complete, heat to 120 ° C and react for 2 hours, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain intermediate 4; the amount ratio of intermediate 3, KH540 and DMSO is 17.9g:3.5mL:140mL; Under heating conditions, intermediate 3 and KH540 undergo the following chemical reaction, and the reaction equation is shown below:
[0017] S5. Blow the dried three-necked flask with nitrogen for 30 minutes to drive away the air in the flask, then add intermediate 4 and DMF (N,N-dimethylformamide), stir thoroughly until mixed, then slowly add 1,3-propylenediamine under nitrogen protection, heat to 120℃ and react for 2h after the addition is complete, cool to room temperature after the reaction is complete, and distill under reduced pressure to obtain an auxiliary agent. The dosage ratio of intermediate 4, 1,3-propylenediamine and DMF is 20.6g:1.7mL:140mL.
[0018] Under heating conditions, intermediate 4 and 1,3-propylenediamine undergo the following chemical reaction, and the reaction equation is shown below:
[0019] The additive contains halogen-free flame retardant elements nitrogen, phosphorus and silicon. The three flame retardant elements work synergistically to give the polyurea repair coating an efficient and safe flame retardant effect.
[0020] The additive contains triazine structure, which can absorb ultraviolet light. Adding the additive containing triazine structure into the polyurea repair coating can make the coating more resistant to aging, thereby protecting the cable sheath and making it less likely to crack and powder. Compared with benzophenone and benzotriazole ultraviolet light absorbers, triazine structures have a higher ultraviolet light absorption coefficient and can strongly absorb ultraviolet rays of 280nm-400nm; at the same time, they are also better in terms of color retention and degradation time. In addition, triazine structures have the advantages of high efficiency, high temperature resistance, light color and good compatibility.
[0021] The additives are rich in fluorine atoms. Adding additives containing multiple fluorine atoms into polyurea repair coatings can give the coatings excellent hydrophobicity. After the polyurea repair coating containing silane oxygen bonds is coated on the cable sheath, the -Si-O-Si- chain formed will migrate to the surface of the film layer. The silicon atom is at the center of the tetrahedron in the compound. According to the tetrahedral structure, the two methyl groups are perpendicular to the plane connecting silicon and two adjacent oxygen atoms. In addition, the Si-O bond is long, so that the three hydrogens on the two non-polar methyl groups are like an open umbrella, which makes it very hydrophobic, and thus makes the coating film have excellent water resistance and adhesion.
[0022] In addition, the silane oxygen bonds in the additive can hydrolyze, condense, crosslink, and form covalent bonds with the hydroxyl groups on the surface of the filler, which not only reduces the surface energy of the filler and evenly disperses it in the polyurea repair coating, improving the wear resistance of the coating, but also makes the additive itself evenly dispersed in the coating, giving full play to the flame retardant, anti-ultraviolet and hydrophobic effects. In addition, the end of the additive also contains an amino group, which can react chemically with the unreacted isocyanate group in the polyurea repair coating, and then the additive can be grafted on the polyurea macromolecular chain. Therefore, the additive of the present invention can be further dispersed and stably present in the polyurea repair coating, and is not easy to migrate and fall out, giving full play to the flame retardant, anti-ultraviolet and hydrophobic effects. This chemical reaction can also further improve the dispersibility of the filler, thereby further improving the wear resistance of the coating, so as to protect the cable sheath and make it not easy to break and crack.
[0023] The beneficial effects of the present invention are as follows: the additive of the present invention contains rich halogen-free flame retardant elements such as nitrogen, phosphorus, silicon, triazine structures and multiple fluorine atoms. In addition, there is a chemical reaction between the additive and the filler, and the additive is grafted onto the polyurea macromolecular chain. The three form a hybrid cross-linked network structure in the polyurea repair coating. This network structure allows the filler and the additive to be highly dispersed and stably present in the polyurea repair coating, and fully exert their functions, giving the polyurea repair coating excellent and stable flame retardant effects, anti-ultraviolet effects, hydrophobicity and wear resistance, thereby protecting and repairing the cable sheath, making it less likely to crack or break, and extending the service life of the cable sheath. DETAILED DESCRIPTION
[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] Example 1
[0026] Preparation of auxiliary agent, the specific steps are as follows: S1. Under nitrogen protection, 7.3 g of 2-(perfluorohexyl)ethyl methacrylate, 1.3 mL of DBU and 105 mL of chloroform were added to a 250 mL three-necked flask. After stirring, a mixed solution of 11.6 mL of diethylaminomethanephosphonate and 15 mL of chloroform was slowly added. After the addition was completed, the temperature was raised to 60 ° C and the reaction was carried out for 48 hours. After the reaction was completed, the reaction was distilled under reduced pressure to obtain intermediate 1; S2, under nitrogen protection, add 7g of cyanuric chloride, 21g of intermediate 1 and 180mL of xylene into a dry 500mL three-necked flask, stir until completely dissolved, then slowly add 4mL of 20wt% sodium bicarbonate solution, after the addition is complete, control the temperature at 0-5°C to react for 8h, after the reaction is completed, add deionized water and shake, let stand to separate, separate the aqueous phase and measure the pH until the pH of the aqueous phase is neutral, then take the organic phase and dry it with anhydrous magnesium sulfate, filter, and distill the filtrate under reduced pressure to obtain intermediate 2; S3. In a dry 500mL brown three-necked flask under nitrogen protection, 6mL of resorcinol, 2.1g of anhydrous aluminum chloride and 100mL of DMSO were added in sequence, and after stirring evenly, a mixed solution of 22.4g of intermediate 2 and 80mL of DMSO was added, and then the mixture was heated to 115°C with stirring, and reacted at 115°C for 12h. After the reaction was completed, the reaction mixture was slowly poured into ice water, the solid was precipitated, filtered, and then recrystallized with 80% methanol aqueous solution to obtain intermediate 3; S4, blow a dry 250mL three-necked flask with nitrogen for 30 minutes to drive away the air in the flask, then add 17.9g of intermediate 3 and 140mL DMSO, stir thoroughly until mixed, then slowly add 3.5mL of KH540 under nitrogen protection, after the addition is complete, heat to 120℃ and react for 2h, cool to room temperature after the reaction is completed, and distill under reduced pressure to obtain intermediate 4; S5. Blow nitrogen gas into a dry 250 mL three-necked flask for 30 min to drive away the air in the flask, then add 20.6 g of intermediate 4 and 140 mL of DMF, stir thoroughly until the mixture is uniform, and then slowly add 1.7 mL of 1,3-propylenediamine under nitrogen protection. After the addition is complete, heat to 120 ° C and react for 2 h. After the reaction is completed, cool to room temperature and distill under reduced pressure to obtain an auxiliary agent.
[0027] Example 2
[0028] Preparation of polyurea repair coating, the specific steps are as follows: (1) Weigh 30 parts of polyether polyol 330N and 5 parts of vinyl polydimethylsiloxane in a reaction kettle, raise the temperature to 125°C while stirring, and introduce nitrogen for atmosphere protection. Dehydrate the above substances under reduced pressure for 3 hours. After dehydration, lower the temperature to 80°C, then add 55 parts of hexamethylene diisocyanate, stir evenly and react for 3 hours to obtain component A; (2) Weigh 40 parts of diaminodiphenyl ether, 30 parts of diethyltoluenediamine, and 12 parts of dipropylene glycol dibenzoate into another reaction kettle, introduce nitrogen protection and dehydrate under reduced pressure at 120° C. for 3 hours, then add 5 parts of nano calcium carbonate, 5 parts of nano titanium dioxide, nano silicon dioxide, kaolin, talcum powder, and 3 parts of the auxiliary agent prepared in Example 1 into the reaction kettle and stir at high speed to obtain component B; (3) Component A and component B are mixed evenly to obtain a polyurea repair coating.
[0029] Example 3
[0030] Preparation of polyurea repair coating, the specific steps are as follows: (1) Weigh 35 parts of polyether polyol 3050 and 6 parts of vinyl polydimethylsiloxane in a reaction kettle, raise the temperature to 125°C while stirring, and introduce nitrogen for atmosphere protection. Dehydrate the above substances under reduced pressure for 3 hours. After completion, lower the temperature to 80°C, then add 60 parts of diphenylmethane diisocyanate, stir evenly and react for 3 hours to obtain component A; (2) Weigh 43 parts of diaminodiphenyl ether, 35 parts of isophorone diamine, and 14 parts of dioctyl terephthalate into another reaction kettle, introduce nitrogen protection, and dehydrate under reduced pressure at 120° C. for 3 h, then add 6 parts of nano-silicon dioxide, 4 parts of kaolin, 4 parts of talc, and 5 parts of the additive prepared in Example 1 into the reaction kettle and stir at high speed to obtain component B; (3) Component A and component B are mixed evenly to obtain a polyurea repair coating.
[0031] Example 4
[0032] Preparation of polyurea repair coating, the specific steps are as follows: (1) Weigh 40 parts of polyether polyol 330N and 8 parts of vinyl polydimethylsiloxane in a reaction kettle, raise the temperature to 125°C while stirring, and introduce nitrogen for atmosphere protection. Decompress and dehydrate the above substances for 3 hours. After completion, lower the temperature to 80°C, then add 65 parts of 3,3-dimethyl-4,4-dicyclohexylmethane diisocyanate, stir evenly and react for 3 hours to obtain component A; (2) Weigh 45 parts of diaminodiphenyl ether, 38 parts of diethyltoluenediamine, and 15 parts of diisononyl phthalate into another reaction kettle, introduce nitrogen protection, and dehydrate under reduced pressure at 120° C. for 3 hours, then add 5 parts of nano calcium carbonate, 5 parts of nano titanium dioxide, 5 parts of talc, and 6 parts of the additive prepared in Example 1 into the reaction kettle and stir at high speed to obtain component B; (3) Component A and component B are mixed evenly to obtain a polyurea repair coating.
[0033] Comparative Example 1 Preparation of auxiliary agent, the specific steps are as follows: The remaining steps remain unchanged, and only step S5 of Example 1 is removed to prepare the auxiliary agent.
[0034] Comparative Example 2 Preparation of auxiliary agent, the specific steps are as follows: The remaining steps remain unchanged, and only steps S4 and S5 of Example 1 are removed to prepare the auxiliary agent.
[0035] Comparative Example 3 The remaining steps remain unchanged, only the auxiliary agent in Example 4 is replaced by the auxiliary agent prepared in Comparative Example 1, thereby preparing a polyurea repair coating.
[0036] Comparative Example 4 The remaining steps remain unchanged, only the auxiliary agent in Example 4 is replaced by the auxiliary agent prepared in Comparative Example 2, thereby preparing a polyurea repair coating.
[0037] Comparative Example 5 Preparation of polyurea repair coating, the specific steps are as follows: The remaining steps remain unchanged, and only the additive in Example 4 is removed, thereby preparing a polyurea repair coating.
[0038] Performance Testing The main indicators of the polyurea repair coatings prepared in Examples 2-4 and Comparative Examples 3-5 were tested according to GB / T23446-2009 "Spray Polyurea Waterproof Coatings", and the flame retardancy test was carried out according to GB / T2406.2-2009. The contact angle of water on the coating surface was used to test the surface hydrophobic effect of the polyurea repair coatings prepared in Examples 2-4 and Comparative Examples 3-5; the test results are shown in the following table:
[0039] It can be seen from the test results in the above table that the polyurea repair coatings prepared in Examples 2-4 of the present invention have excellent flame retardancy, hydrophobicity, wear resistance and resistance to ultraviolet aging.
[0040] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0041] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.
Claims
1. A polyurea repair coating for distribution cable sheath below 35kV, characterized in that: The method comprises component A and component B; the component A comprises the following raw materials in parts by weight: 55-65 parts of isocyanate, 30-40 parts of polyether polyol, and 5-8 parts of vinyl polydimethylsiloxane; the component B comprises the following raw materials in parts by weight: 40-45 parts of amino polyether, 30-38 parts of chain extender, 12-15 parts of plasticizer, 10-15 parts of filler, and 3-6 parts of auxiliary agent; Wherein, the auxiliary agent is prepared by the following steps: S1. Add 2-(perfluorohexyl)ethyl methacrylate, DBU and chloroform into a flask under nitrogen protection, stir, add diethylaminomethanephosphonate and chloroform, react at 60° C. for 48 h, and distill under reduced pressure to obtain intermediate 1; S2, under nitrogen protection, add cyanuric chloride, intermediate 1 and xylene into a flask, stir, add 20wt% sodium bicarbonate solution, react at 0-5℃ for 8h, add deionized water, separate, measure pH, take the organic phase, dry, filter, and distill the filtrate under reduced pressure to obtain intermediate 2; S3, under nitrogen protection, add resorcinol, anhydrous aluminum chloride and DMSO into a flask, stir, add intermediate 2 and DMSO, react at 115°C for 12 hours, pour into ice water, precipitate solid, filter, and recrystallize to obtain intermediate 3; S4, purging the flask with nitrogen, adding intermediate 3 and DMSO, stirring, adding KH540, reacting at 120°C for 2h, cooling, and distilling under reduced pressure to obtain intermediate 4; S5. Purge the flask with nitrogen, add intermediate 4 and DMF, stir, add 1,3-propylenediamine, react at 120°C for 2h, cool, and distill under reduced pressure to obtain an auxiliary agent.
2. The polyurea repair coating for the sheath of distribution cables below 35 kV according to claim 1, characterized in that: The amount ratio of 2-(perfluorohexyl)ethyl methacrylate, diethylaminomethanephosphonate, DBU and chloroform in step S1 is 7.3g:11.6mL:1.3mL:120mL; the molar ratio of cyanuric chloride and intermediate 1 in step S2 is 1.05-1.1:1; the amount ratio of intermediate 2, resorcinol, anhydrous aluminum chloride and DMSO in step S3 is 22.4g:6mL:2.1g:180mL; the amount ratio of intermediate 3, KH540 and DMSO in step S4 is 17.9g:3.5mL:140mL; the amount ratio of intermediate 4, 1,3-propylenediamine and DMF in step S5 is 20.6g:1.7mL:140mL.
3. The polyurea repair coating for the sheath of distribution cables below 35 kV according to claim 1, characterized in that: The isocyanate is one or more of 3,3-dimethyl-4,4-dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.
4. The polyurea repair coating for distribution cable sheath below 35 kV according to claim 1, characterized in that: The polyether polyol is one or both of polyether polyol 330N and polyether polyol 3050.
5. The polyurea repair coating for distribution cable sheath below 35 kV according to claim 1, characterized in that: The amino polyether is diaminodiphenyl ether.
6. The polyurea repair coating for distribution cable sheath below 35 kV according to claim 1, characterized in that: The chain extender is one or both of diethyltoluenediamine and isophoronediamine.
7. The polyurea repair coating for distribution cable sheath below 35 kV according to claim 1, characterized in that: The plasticizer is one or more of diisononyl phthalate, dioctyl terephthalate, and dipropylene glycol dibenzoate.
8. The polyurea repair coating for distribution cable sheath below 35 kV according to claim 1, characterized in that: The filler is one or more of nano calcium carbonate, nano titanium dioxide, nano silicon dioxide, kaolin and talcum powder.