An insulating flame-retardant tape and its preparation method

Abstract

This invention belongs to the technical field of insulating flame-retardant tape, specifically relating to an insulating flame-retardant tape and its preparation method. The invention utilizes a flame-retardant additive prepared by reacting phytic acid with 3-amino-5-methylpyrazole, triaminopyrimidine, and polyetheramine-2000. This additive is then compounded with magnesium hydroxide, zinc borate, and melamine to prepare a modified flame retardant that generates an expanded char layer during combustion to block heat and oxygen, achieving a flame-retardant effect. An alumina layer is formed on synthetic diamond micropowder, acting as an insulating and thermally conductive additive, improving the insulation, abrasion resistance, and corrosion resistance of the insulating flame-retardant tape. It also assists in uniform heat conduction, preventing localized overheating and combustion. The insulating material is prepared by encapsulating the uniformly dispersed insulating and thermally conductive additive, anisoleyl, and boron nitride ceramic powder in epoxy resin and curing it, thereby enhancing the tape's dielectric breakdown performance. The insulating flame-retardant tape prepared by this invention exhibits excellent insulation and flame-retardant properties and does not contain halogen-based flame retardants. The production process is also environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the technical field of insulating flame-retardant tape, specifically relating to an insulating flame-retardant tape and its preparation method. Background Technology

[0002] Adhesive tape consists of two parts: a substrate and an adhesive. It connects two or more unconnected objects together through bonding. The substrate of the tape can be made of materials such as polyethylene, polypropylene, and paper, while the adhesive can be made of materials such as acrylic resin, butyl rubber, and polyester resin. However, these commonly used substrate and adhesive materials are all flammable. In order to make the tape have flame-retardant and insulating properties, flame retardants and insulating agents need to be added to modify the tape.

[0003] Chinese invention patent CN113930168B discloses a flame-retardant insulating electrical tape, comprising a first adhesive layer 1 and a second adhesive layer 2 laminated together. The first adhesive layer 1 contains the following components by weight: 100 parts chlorinated butyl rubber, 10-20 parts POE elastomer, 3-10 parts liquid polyisobutylene, 5-15 parts fumed silica, 100-150 parts hydrophobic aluminum hydroxide, 15-30 parts decabromodiphenyl ethane, 5-10 parts liquid chlorinated paraffin, 5-10 parts trioctyl phosphate, 0.5-2 parts alkyl coupling agent, and 2-5 parts antioxidant. Chinese invention patent CN115926638B discloses a flame-retardant waterproof insulating composite tape, comprising an upper adhesive layer and a lower backing layer. The upper adhesive layer is composed of butyl rubber, magnesium hydroxide, decabromodiphenyl ethane, silica powder, magnesium silicate powder, polyisobutylene, carbon black, and stearic acid; the lower liner layer is composed of ethylene propylene rubber, butyl rubber, chlorinated polyethylene, polyisobutylene, magnesium hydroxide, decabromodiphenyl ethane, silica powder, magnesium silicate powder, chlorinated paraffin, carbon black, stearic acid, and polyethylene wax. However, existing technologies suffer from environmental problems due to the use of halogenated flame retardants and insufficient adhesive strength of the tape layers. Summary of the Invention

[0004] The purpose of this invention is to provide an insulating flame-retardant tape and its preparation method, which solves the technical problems of insufficient environmental protection of halogen flame retardants and insufficient adhesive adhesion of tape layers in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An insulating and flame-retardant tape, comprising, from top to bottom, a base film layer, an adhesive layer, a flame-retardant adhesive layer, an insulating adhesive layer, and a release film layer.

[0007] The base film layer is composed of the following components, in parts by weight: 60-70 parts high-density polyethylene, 30-40 parts low-density polyethylene, 0.5-2 parts antioxidant, and 1-5 parts lubricant;

[0008] The adhesive layer is composed of the following components, in parts by weight: 60-70 parts hydroxyl acrylic resin, 30-40 parts methacrylic resin, 0.5-2 parts defoamer, and 0.5-2 parts leveling agent;

[0009] The release liner is one or more combinations of polyethylene release liner, polypropylene release liner, and polyester release liner;

[0010] The flame-retardant adhesive layer is composed of the following components, in parts by weight: 30-50 parts butyl rubber, 20-30 parts styrene-butadiene rubber, 15-25 parts modified flame retardant, 1-5 parts coupling agent, 0.5-2 parts antioxidant, and 30-50 parts filler.

[0011] The insulating adhesive layer is composed of the following components, in parts by weight: 30-50 parts butyl rubber, 20-30 parts EPDM rubber, 15-30 parts insulating material, 1-5 parts coupling agent, 0.5-2 parts antioxidant, and 30-50 parts filler.

[0012] Preferably, the antioxidants in the base film layer, flame-retardant adhesive layer, and insulating adhesive layer are one or more combinations of 168, 1010, and 1076.

[0013] Preferably, the lubricant of the base film layer is one or a combination of polyethylene wax, sodium stearate and polyethylene glycol.

[0014] Preferably, the defoamer of the adhesive layer is one or more of BYK-021, BYK-028 and BYK-A530, and the leveling agent is one or more of ASK-191, LD-9601 and LB-575.

[0015] Preferably, the coupling agents for the flame-retardant adhesive layer and the insulating adhesive layer are one or more combinations of KH-550, KH-560, KH-570 and KH-590.

[0016] Preferably, the fillers in the flame-retardant adhesive layer and the insulating adhesive layer are one or more combinations of fumed silica, calcium carbonate and montmorillonite.

[0017] A method for preparing an insulating flame-retardant tape includes the following steps:

[0018] S1. Preparation of base film layer: Weigh the materials used for the base film layer, add the weighed materials to a high-speed mixer and mix for 10~20 minutes, then add to an extruder for extrusion and calendering, controlling the thickness to 0.2~0.5 mm to obtain the base film layer;

[0019] S2. Preparation of adhesive layer material: Weigh the materials used for the adhesive layer, dilute the hydroxyl acrylic resin and methacrylic resin in deionized water, add leveling agent and defoamer and stir evenly to obtain the adhesive layer material;

[0020] S3. Preparation of adhesive paste: Weigh the materials used for flame retardant adhesive layer and insulating adhesive layer respectively. Mix the materials used for flame retardant adhesive layer and insulating adhesive layer evenly, and then mix them through a two-roll mill and a mixing mill to produce sheets. Crush and granulate, add organic solvent, and stir at 70~85℃ until there is no gel-like solid. Let stand for 24 hours to obtain flame retardant adhesive paste and insulating adhesive paste.

[0021] S4. Adhesive coating: After the base film layer is coated with adhesive material through the composite molding machine, flame retardant adhesive and insulating adhesive are coated in sequence, composite molding is performed, and the film is wound up by the guide roller.

[0022] S5. Applying the release film layer: After cooling by rollers, the release film layer is applied, with the thickness controlled at 1.4~1.8mm. The tape is then wound up by a traction machine to obtain a large roll of insulating flame-retardant tape.

[0023] S6. Cutting and Packaging: Place the large roll of insulating flame-retardant tape into a slitting machine to cut and package it to obtain the insulating flame-retardant tape product.

[0024] Preferably, in S1, the extruder inlet temperature is 130~150℃ and the extrusion outlet temperature is 160~180℃.

[0025] Preferably, in step S2, deionized water is added to dilute the acrylic resin to a total content of 30-50 wt%.

[0026] Preferably, the organic solvent in S3 is one or a combination of n-hexane, n-propanol, and isopropanol.

[0027] Preferably, in S3, the initial mixing temperature of the flame-retardant adhesive layer is 120~150℃, the mixing temperature is 140~160℃, and the initial mixing temperature of the insulating adhesive layer is 140~160℃, the mixing temperature is 160~180℃.

[0028] Preferably, the preparation method of the modified flame retardant includes the following steps:

[0029] S11. Dissolve 3-amino-5-methylpyrazole in deionized water, add phytic acid, react at 110~150℃ for 1~2h, then add triaminopyrimidine and react at 120~150℃ for 1~2h, and dry to obtain mixture 1;

[0030] S12. Add mixture 1 to polyetheramine-2000 solution, react at 60~70℃ for 1~2h, and dry to obtain flame retardant additive;

[0031] S13. Mix the flame retardant additive with magnesium hydroxide, zinc borate and melamine for 10-20 minutes to obtain the modified flame retardant.

[0032] Preferably, the modified flame retardant comprises, by weight, 10-20 parts of 3-amino-5-methylpyrazole, 10-50 parts of triaminopyrimidine, 100 parts of deionized water, 10-15 parts of phytic acid, 10-20 parts of polyetheramine-2000 solution, 5-25 parts of magnesium hydroxide, 5-25 parts of zinc borate, and 10-15 parts of melamine.

[0033] Preferably, the reaction mechanism involved in the flame retardant additive is as follows:

[0034]

[0035] R1 represents the phytic acid remaining after removing the phosphate group, and R2 represents the 3-amino-5-methylpyrazole, triaminopyrimidine, and polyetheramine-2000 remaining after removing the amino group. The amino groups in 3-amino-5-methylpyrazole and triaminopyrimidine undergo amidation reactions with the carboxyl groups on multiple phosphate groups in phytic acid to synthesize a mixture with multiple phosphoramide groups. Introducing nitrogen-rich groups can increase the thermal stability and mechanical properties of the material. During combustion, phytic acid decomposes to generate phosphate, which catalyzes the triaminopyrimidine and 3-amino-5-methylpyrazole to generate a large amount of nitrogen and water vapor during combustion. These gases react with the polymer matrix to form an expanded char layer, achieving a flame-retardant effect.

[0036] Preferably, the method for preparing the insulating material includes the following steps:

[0037] S21. Add the insulating and thermally conductive additive to the anisoleyl and boron nitride ceramic powder, stir for 10-15 minutes to obtain the insulating mixed powder.

[0038] S22. Add the insulating mixed powder to the epoxy resin, stir and mix evenly, add the polyetheramine curing agent, and cure at 50~60℃ for 3~4h. Then crush and granulate to obtain the insulating material.

[0039] Preferably, the insulating material comprises, by weight, 30-50 parts of insulating and thermally conductive additive, 10-20 parts of anisole, 20-30 parts of boron nitride ceramic powder, 50-60 parts of epoxy resin, and 20-40 parts of polyetheramine curing agent.

[0040] Preferably, the particle size of the boron nitride ceramic powder in S21 is between 10 and 20 μm.

[0041] Preferably, the preparation method of the insulating and thermally conductive additive includes the following steps:

[0042] S31. Add synthetic diamond micro powder and surfactant to deionized water and ultrasonically disperse at 70~80℃ for 10~30min to obtain a suspension.

[0043] S32. Keep the suspension at 75~80℃, add 10wt% aluminum nitrate solution dropwise while stirring, and simultaneously add 10wt% sodium hydroxide solution dropwise to maintain the pH of the system at 6~7. After the aluminum nitrate solution is added dropwise over 1~2 hours, continue stirring and reacting for 2~3 hours. After filtration and drying, calcine at 600~700℃ for 3~4 hours to obtain the insulating and thermally conductive additive.

[0044] Preferably, the insulating and thermally conductive additive comprises, by weight, 5-10 parts of synthetic diamond micro powder, 1-5 parts of surfactant, 15-20 parts of aluminum nitrate solution, and 100 parts of deionized water.

[0045] Preferably, the particle size of the synthetic diamond powder in S31 is between 0.1 and 5 μm.

[0046] Preferably, the surfactant in S31 is one or more combinations of sodium hexadecyl sulfonate, dodecyl alcohol polyoxyethylene ether, and lauramide propyl betaine.

[0047] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0048] 1. Based on existing technology, this invention optimizes the composition and preparation process of the flame-retardant adhesive layer and the insulating adhesive layer. The resulting insulating flame-retardant tape not only has strong adhesion but also good flexibility and mechanical properties. Using butyl rubber and styrene-butadiene rubber as the flame-retardant adhesive layer substrate, it has excellent heat resistance and air tightness. Using butyl rubber and EPDM rubber as the insulating adhesive layer substrate, it has excellent heat resistance and air tightness, as well as excellent chemical corrosion resistance and weather resistance. Furthermore, the insulating flame-retardant tape prepared by this invention does not contain halogenated flame retardants, and the production process is environmentally friendly.

[0049] 2. In this invention, 3-amino-5-methylpyrazole and triaminopyrimidine are grafted onto phytic acid via reaction. The flame retardant additive, which is combined with polyetheramine through reaction, is a good acid source and carbon source. The flame retardant additive and the gas source melamine are compounded to generate an expanded char layer during combustion to block heat and isolate oxygen, thereby achieving a flame retardant effect. Polyetheramine-2000 is loaded with nitrogen-rich groups and phytic acid through an amidation reaction, so that the nitrogen-rich groups and phytic acid are more uniformly dispersed in the adhesive layer and have higher interfacial compatibility. Zinc borate can cover the surface of the expanded char layer with a glassy protective layer to improve the density and heat insulation of the char layer.

[0050] 3. This invention generates a dense layer of alumina on artificial diamond micropowder as an insulating and thermally conductive additive, which not only improves the insulation, wear resistance and corrosion resistance of the insulating and flame-retardant tape, but also helps the tape to conduct heat evenly, prevents the tape from burning due to excessive local temperature, and gives the insulating adhesive layer a certain flame-retardant property.

[0051] 4. The insulating material of the present invention is prepared by curing epoxy resin to encapsulate uniformly dispersed insulating and thermally conductive additives, anisole, and boron nitride ceramic powder. The epoxy resin encapsulation of anisole prevents the active ingredient from migrating out during tape production, and can improve the partial discharge initiation voltage and extinction voltage of the tape, and to a certain extent slow down the growth rate of electrical treeing on the tape. The combination of insulating and thermally conductive additives, anisole, and boron nitride ceramic powder enhances the dielectric breakdown performance of the tape. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 A schematic diagram of the layer structure of an insulating flame-retardant tape according to the present invention is shown.

[0054] Explanation of key figure labels:

[0055] 1-Substrate layer, 2-Adhesive layer, 3-Flame-retardant adhesive layer, 4-Insulating adhesive layer, 5-Release film layer. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Example 1, see Figure 1 As shown, an insulating flame-retardant tape of this embodiment is provided with a base film layer 1, an adhesive layer 2, a flame-retardant adhesive layer 3, an insulating adhesive layer 4, and a release film layer 5 from top to bottom.

[0058] The base film layer is composed of the following components, in parts by weight: 60 parts high-density polyethylene, 40 parts low-density polyethylene, 2 parts antioxidant, and 3 parts lubricant;

[0059] The adhesive layer is composed of the following components, in parts by weight: 65 parts hydroxyl acrylic resin, 35 parts methacrylic resin, 1 part defoamer, and 1 part leveling agent;

[0060] The release liner is a polyethylene release liner;

[0061] The flame-retardant adhesive layer is composed of the following components, in parts by weight: 30 parts butyl rubber, 30 parts styrene-butadiene rubber, 20 parts modified flame retardant, 3 parts coupling agent, 2 parts antioxidant and 30 parts filler;

[0062] The insulating adhesive layer is composed of the following components, in parts by weight: 30 parts butyl rubber, 20 parts EPDM rubber, 20 parts insulating material, 3 parts coupling agent, 1 part antioxidant, and 30 parts filler.

[0063] The antioxidant type of the base film layer, flame retardant adhesive layer and insulating adhesive layer is 168; the lubricant of the base film layer is polyethylene wax; the defoamer of the adhesive layer is BYK-021 and the leveling agent is ASK-191; the coupling agent type of the flame retardant adhesive layer and the insulating adhesive layer is KH-550; the filler of the flame retardant adhesive layer and the insulating adhesive layer is fumed silica.

[0064] The method for preparing an insulating flame-retardant tape according to this embodiment includes the following steps:

[0065] S1. Preparation of base film layer: Weigh the materials used for the base film layer, add the weighed materials to a high-speed mixer and mix for 10 minutes, then add them to an extruder for extrusion and calendering, controlling the thickness to 0.2 mm to obtain the base film layer;

[0066] S2. Preparation of adhesive layer material: Weigh the materials used for the adhesive layer, add hydroxyl acrylic resin and methacrylic resin to deionized water and dilute until the total content of acrylic resin is 40wt%, add leveling agent and defoamer and stir evenly to obtain adhesive layer material;

[0067] S3. Preparation of adhesive paste: Weigh the materials used for the flame-retardant adhesive layer and the insulating adhesive layer respectively. Mix the materials used for the flame-retardant adhesive layer and the insulating adhesive layer evenly, and then pass them through a two-roll mill and a mixing mill. The two-roll temperature of the flame-retardant adhesive layer is 130℃ and the two-roll temperature is 150℃. The two-roll temperature of the insulating adhesive layer is 150℃ and the two-roll temperature is 170℃. After mixing and extruding into sheets, crush and granulate. Add n-hexane and stir at 75℃ until there is no gel-like solid. Let stand for 24 hours to obtain flame-retardant adhesive paste and insulating adhesive paste.

[0068] S4. Adhesive coating: After the base film layer is coated with adhesive material through the composite molding machine, flame retardant adhesive and insulating adhesive are coated in sequence, composite molding is performed, and the film is wound up by the guide roller.

[0069] S5. Applying the release film layer: After cooling by the roller, the release film layer is applied, with the thickness controlled at 1.4mm. The tape is then wound up by a traction machine to obtain a large roll of insulating flame-retardant tape.

[0070] S6. Cutting and Packaging: Place the large roll of insulating flame-retardant tape into a slitting machine to cut and package it to obtain the insulating flame-retardant tape product.

[0071] The preparation method of the modified flame retardant in this embodiment includes the following steps:

[0072] S11. Dissolve 10 parts of 3-amino-5-methylpyrazole in deionized water, add 10 parts of phytic acid, react at 130°C for 2 hours, then add 50 parts of triaminopyrimidine and react at 150°C for 2 hours, and dry to obtain mixture 1.

[0073] S12. Add mixture 1 to 10 parts of polyetheramine-2000 solution, react at 70°C for 2 hours, and dry to obtain flame retardant additive;

[0074] S13. Mix the flame retardant additive with 10 parts magnesium hydroxide, 15 parts zinc borate and 15 parts melamine for 20 minutes to obtain the modified flame retardant.

[0075] The method for preparing the insulating material in this embodiment includes the following steps:

[0076] S21. Add 30 parts of insulating and thermally conductive additive to 15 parts of anisole and 25 parts of 10μm boron nitride ceramic powder, stir for 15 minutes to obtain insulating mixed powder.

[0077] S22. Add the insulating mixed powder to 50 parts of epoxy resin, stir and mix evenly, add 30 parts of polyetheramine-650 curing agent, cure at 60℃ for 3 hours, and then crush and granulate to obtain the insulating material.

[0078] The preparation method of the insulating and thermally conductive additive in this embodiment includes the following steps:

[0079] S31. Add 7 parts of synthetic diamond micro powder and 2 parts of sodium hexadecyl sulfonate to 100 parts of deionized water, and ultrasonically disperse at 70°C for 20 min to obtain a suspension.

[0080] S32. Keep the suspension at 70°C and add 15 parts of 10wt% aluminum nitrate solution dropwise while stirring. At the same time, add 10wt% sodium hydroxide solution dropwise to maintain the pH of the system at 7. After the aluminum nitrate solution is added dropwise over 2 hours, continue stirring and reacting for another 2 hours. After filtration and drying, calcine at 700°C for 3 hours to obtain the insulating and thermally conductive additive.

[0081] Example 2, see Figure 1 As shown, an insulating flame-retardant tape of this embodiment is provided with a base film layer 1, an adhesive layer 2, a flame-retardant adhesive layer 3, an insulating adhesive layer 4, and a release film layer 5 from top to bottom.

[0082] The base film layer is composed of the following components, in parts by weight: 70 parts high-density polyethylene, 30 parts low-density polyethylene, 2 parts antioxidant, and 5 parts lubricant;

[0083] The adhesive layer is composed of the following components, in parts by weight: 60 parts hydroxyl acrylic resin, 40 parts methacrylic resin, 2 parts defoamer and 2 parts leveling agent;

[0084] The separator layer is a polyester separator layer;

[0085] The flame-retardant adhesive layer is composed of the following components, in parts by weight: 50 parts butyl rubber, 20 parts styrene-butadiene rubber, 25 parts modified flame retardant, 3 parts coupling agent, 1 part antioxidant, and 45 parts filler.

[0086] The insulating adhesive layer is composed of the following components, in parts by weight: 50 parts butyl rubber, 30 parts EPDM rubber, 25 parts insulating material, 3 parts coupling agent, 1 part antioxidant, and 30 parts filler.

[0087] The antioxidant type of the base film layer, flame retardant adhesive layer, and insulating adhesive layer is 1076; the lubricant of the base film layer is polyethylene wax; the defoamer of the adhesive layer is BYK-028, and the leveling agent is LD-9601; the coupling agent type of the flame retardant adhesive layer and the insulating adhesive layer is KH-570; and the filler of the flame retardant adhesive layer and the insulating adhesive layer is calcium carbonate.

[0088] The method for preparing an insulating flame-retardant tape according to this embodiment includes the following steps:

[0089] S1. Preparation of base film layer: Weigh the materials used for the base film layer, add the weighed materials to a high-speed mixer and mix for 15 minutes, then add them to an extruder for extrusion and calendering, controlling the thickness to 0.4 mm to obtain the base film layer;

[0090] S2. Preparation of adhesive layer material: Weigh the materials used for the adhesive layer, add hydroxyl acrylic resin and methacrylic resin to deionized water and dilute until the total content of acrylic resin is 30wt%, add leveling agent and defoamer and stir evenly to obtain adhesive layer material;

[0091] S3. Preparation of adhesive paste: Weigh the materials used for the flame-retardant adhesive layer and the insulating adhesive layer respectively. Mix the materials used for the flame-retardant adhesive layer and the insulating adhesive layer evenly, and then pass them through a two-roll mill and a mixing mill. The two-roll temperature of the flame-retardant adhesive layer is 125℃ and the two-roll temperature is 155℃. The two-roll temperature of the insulating adhesive layer is 155℃ and the two-roll temperature is 175℃. After mixing and extruding into sheets, crush and granulate. Add n-propanol and stir at 80℃ until there is no gel-like solid. Let stand for 24 hours to obtain flame-retardant adhesive paste and insulating adhesive paste.

[0092] S4. Adhesive coating: After the base film layer is coated with adhesive material through the composite molding machine, flame retardant adhesive and insulating adhesive are coated in sequence, composite molding is performed, and the film is wound up by the guide roller.

[0093] S5. Applying the release film layer: After cooling by rollers, the release film layer is applied, with the thickness controlled at 1.8mm. The tape is then wound up by a traction machine to obtain a large roll of insulating flame-retardant tape.

[0094] S6. Cutting and Packaging: Place the large roll of insulating flame-retardant tape into a slitting machine to cut and package it to obtain the insulating flame-retardant tape product.

[0095] The modified flame retardant in this embodiment is prepared using the same method as in Example 1.

[0096] The difference between the insulating material in this embodiment and that in Embodiment 1 is that the materials used in the insulating material by weight are changed to 50 parts of insulating and thermally conductive additive, 20 parts of anisole, 20 parts of boron nitride ceramic powder, 60 parts of epoxy resin, and 30 parts of polyetheramine D-230 curing agent.

[0097] The insulating and thermally conductive additive in this embodiment is prepared using the same method as in Example 1.

[0098] Example 3, see Figure 1 As shown, an insulating flame-retardant tape of this embodiment is provided with a base film layer 1, an adhesive layer 2, a flame-retardant adhesive layer 3, an insulating adhesive layer 4, and a release film layer 5 from top to bottom.

[0099] The base film layer is composed of the following components, in parts by weight: 65 parts high-density polyethylene, 35 parts low-density polyethylene, 0.5 parts antioxidant, and 2 parts lubricant;

[0100] The adhesive layer is composed of the following components, in parts by weight: 70 parts hydroxyl acrylic resin, 30 parts methacrylic resin, 0.5 parts defoamer, and 0.5 parts leveling agent;

[0101] The release liner is a polypropylene release liner;

[0102] The flame-retardant adhesive layer is composed of the following components, in parts by weight: 30 parts butyl rubber, 30 parts styrene-butadiene rubber, 20 parts modified flame retardant, 3 parts coupling agent, 2 parts antioxidant and 30 parts filler;

[0103] The insulating adhesive layer is composed of the following components, in parts by weight: 30 parts butyl rubber, 20 parts EPDM rubber, 20 parts insulating material, 3 parts coupling agent, 1 part antioxidant, and 30 parts filler.

[0104] The antioxidants in the base film layer, flame-retardant adhesive layer, and insulating adhesive layer are all of type 1010; the lubricant in the base film layer is sodium stearate; the defoamer in the adhesive layer is BYK-A530, and the leveling agent is LB-575; the coupling agent in the flame-retardant adhesive layer and the insulating adhesive layer is KH-560; and the filler in the flame-retardant adhesive layer and the insulating adhesive layer is montmorillonite.

[0105] The method for preparing an insulating flame-retardant tape according to this embodiment includes the following steps:

[0106] S1. Preparation of base film layer: Weigh the materials used for the base film layer, add the weighed materials to a high-speed mixer and mix for 10 minutes, then add them to an extruder for extrusion and calendering, controlling the thickness to 0.3 mm to obtain the base film layer;

[0107] S2. Preparation of adhesive layer material: Weigh the materials used for the adhesive layer, add hydroxyl acrylic resin and methacrylic resin to deionized water and dilute until the total content of acrylic resin is 40wt%, add leveling agent and defoamer and stir evenly to obtain adhesive layer material;

[0108] S3. Preparation of adhesive paste: Weigh the materials used for the flame-retardant adhesive layer and the insulating adhesive layer respectively. Mix the materials used for the flame-retardant adhesive layer and the insulating adhesive layer evenly, and then pass them through a two-roll mill and a mixing mill. The two-roll temperature of the flame-retardant adhesive layer is 150℃ and the two-roll temperature is 160℃. The two-roll temperature of the insulating adhesive layer is 160℃ and the two-roll temperature is 180℃. After mixing and extruding into sheets, crush and granulate. Add isopropanol and stir at 70℃ until there is no gel-like solid. Let stand for 24 hours to obtain flame-retardant adhesive paste and insulating adhesive paste.

[0109] S4. Adhesive coating: After the base film layer is coated with adhesive material through the composite molding machine, flame retardant adhesive and insulating adhesive are coated in sequence, composite molding is performed, and the film is wound up by the guide roller.

[0110] S5. Applying the release film layer: After cooling by rollers, the release film layer is applied, with the thickness controlled at 1.6mm. The tape is then wound up by a traction machine to obtain a large roll of insulating flame-retardant tape.

[0111] S6. Cutting and Packaging: Place the large roll of insulating flame-retardant tape into a slitting machine to cut and package it to obtain the insulating flame-retardant tape product.

[0112] The difference between the modified flame retardant in this embodiment and that in Example 1 is that the modified flame retardant uses 20 parts by weight of 3-amino-5-methylpyrazole, 40 parts of triaminopyrimidine, 100 parts of deionized water, 15 parts of phytic acid, 10 parts of polyetheramine-2000 solution, 25 parts of magnesium hydroxide, 5 parts of zinc borate and 10 parts of melamine.

[0113] The insulating material and the insulating thermal conductive additive in this embodiment are prepared in the same way as in Example 1.

[0114] Comparative Example 1 differs from Example 1 in that the 3-amino-5-methylpyrazole and triaminopyrimidine components in the modified flame retardant are replaced with diethylenetriamine.

[0115] Comparative Example 2 differs from Example 1 in that the insulating materials are directly blended and prepared without the addition of epoxy resin and curing agent.

[0116] Comparative Example 3 differs from Example 1 in that the insulating and thermally conductive additive is replaced with alumina micro powder.

[0117] Performance testing

[0118] Mechanical property testing

[0119] The tensile strength and elongation at break of the tapes prepared in each example and comparative example were determined according to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0120] The peel strength of the adhesive tapes prepared in each example and comparative example was determined according to GB / T 2792-2014 "Test method for peel strength of adhesive tape".

[0121] The test results are shown in Table 1 below:

[0122] Table 1

[0123] Serial Number Tensile strength (MPa) Elongation at break (%) Adhesive tape peel strength (N / cm) Example 1 17.1 416 23.7 Example 2 16.8 413 22.6 Example 3 16.6 415 23.4 Comparative Example 1 15.2 378 20.9 Comparative Example 2 16.1 409 23.7 Comparative Example 3 16.3 414 21.1

[0124] Flame retardant performance test

[0125] The limiting oxygen index of the tapes prepared in each example and comparative example was determined according to GB / T 10707-2008 "Determination of the flammability of rubber".

[0126] The flame retardancy ratings of the tapes prepared in each example and comparative example were determined according to UL 94-2020, "Tests for flammability of plastic materials for use in equipment and electrical components".

[0127] The test results are shown in Table 2 below:

[0128] Table 2

[0129] Serial Number Limiting oxygen index (%) Flame retardant rating Example 1 32.9 V-0 Example 2 33.6 V-0 Example 3 33.1 V-0 Comparative Example 1 25.7 V-1 Comparative Example 2 31.7 V-0 Comparative Example 3 30.4 V-0

[0130] Insulation performance test

[0131] The breakdown voltage strength of the tapes prepared in each example and comparative example was determined according to GB / T 1695-2005 "Determination of power frequency breakdown voltage strength and withstand voltage of vulcanized rubber".

[0132] The volume resistivity of the tapes prepared in each example and comparative example was determined according to GB / T 1692-2008 "Determination of Insulation Resistivity of Vulcanized Rubber".

[0133] The test results are shown in Table 3 below:

[0134] Table 3

[0135] Serial Number Breakdown voltage (kV / mm) Volume resistivity (Ω×mm) Example 1 25.7 <![CDATA[4.5×10 15 ]]> Example 2 26.1 <![CDATA[4.7×10 15 ]]> Example 3 26.2 <![CDATA[4.6×10 15 ]]> Comparative Example 1 23.1 <![CDATA[3.4×10 15 ]]> Comparative Example 2 21.4 <![CDATA[6.9×10 14 ]]> Comparative Example 3 23.6 <![CDATA[7.1×10 14 ]]>

[0136] According to the data in the table above, the tensile strength of the tapes prepared in Examples 1-3 is between 16.6 and 17.1 MPa, the elongation at break is between 413 and 416%, and the peel strength is between 22.6 and 23.7 N / cm, indicating that the tapes prepared by this invention have good mechanical properties and strong adhesion; the limiting oxygen index is between 32.9 and 33.6%, and the flame retardancy rating is V-0, indicating that the tapes prepared by this invention have excellent flame retardant properties; the breakdown voltage is between 25.7 and 26.3 kV / mm, and the volume resistivity is 4.5 × 10⁻⁶. 15 ~4.7×10 15 The values ​​between Ω and mm indicate that the tape prepared according to this invention has excellent dielectric breakdown and insulation properties. In Comparative Example 1, because the 3-amino-5-methylpyrazole and triaminopyrimidine components in the modified flame retardant were replaced with diethylenetriamine, the rubber in the adhesive layer underwent an addition reaction with the diethylenetriamine, resulting in a more brittle adhesive layer. Therefore, Comparative Example 1 had the lowest tensile strength, elongation at break, and peel strength.

[0137] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0138] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An insulating and flame-retardant tape, characterized in that, From top to bottom, the following layers are arranged in sequence: base film layer (1), adhesive layer (2), flame retardant adhesive layer (3), insulating adhesive layer (4) and release film layer (5); The base film layer is composed of the following components, in parts by weight: 60-70 parts high-density polyethylene, 30-40 parts low-density polyethylene, 0.5-2 parts antioxidant, and 1-5 parts lubricant; The adhesive layer is composed of the following components, in parts by weight: 60-70 parts hydroxyl acrylic resin, 30-40 parts methacrylic resin, 0.5-2 parts defoamer, and 0.5-2 parts leveling agent; The flame-retardant adhesive layer is composed of the following components, in parts by weight: 30-50 parts butyl rubber, 20-30 parts styrene-butadiene rubber, 15-25 parts modified flame retardant, 1-5 parts coupling agent, 0.5-2 parts antioxidant, and 30-50 parts filler. The insulating adhesive layer is composed of the following components, in parts by weight: 30-50 parts butyl rubber, 20-30 parts EPDM rubber, 15-30 parts insulating material, 1-5 parts coupling agent, 0.5-2 parts antioxidant, and 30-50 parts filler; The preparation method of the modified flame retardant includes the following steps: S11. Dissolve 3-amino-5-methylpyrazole in deionized water, add phytic acid, react at 110~150℃ for 1~2h, then add triaminopyrimidine and react at 120~150℃ for 1~2h, and dry to obtain mixture 1; S12. Add mixture 1 to polyetheramine-2000 solution, react at 60~70℃ for 1~2h, and dry to obtain flame retardant additive; S13. Mix the flame retardant additive with magnesium hydroxide, zinc borate and melamine for 10-20 minutes to obtain the modified flame retardant; The modified flame retardant comprises, by weight, 10-20 parts of 3-amino-5-methylpyrazole, 10-50 parts of triaminopyrimidine, 100 parts of deionized water, 10-15 parts of phytic acid, 10-20 parts of polyetheramine-2000 solution, 5-25 parts of magnesium hydroxide, 5-25 parts of zinc borate, and 10-15 parts of melamine. The method for preparing the insulating material includes the following steps: S21. Add the insulating and thermally conductive additive to the anisoleyl and boron nitride ceramic powder, stir for 10-15 minutes to obtain the insulating mixed powder. S22. Add the insulating mixed powder to the epoxy resin, stir and mix evenly, add the polyetheramine curing agent, and cure at 50~60℃ for 3~4h. Then crush and granulate to obtain the insulating material. The preparation method of the insulating and thermally conductive additive includes the following steps: S31. Add synthetic diamond micro powder and surfactant to deionized water and ultrasonically disperse at 70~80℃ for 10~30min to obtain a suspension. S32. Keep the suspension at 75~80℃, add 10wt% aluminum nitrate solution dropwise while stirring, and simultaneously add 10wt% sodium hydroxide solution dropwise to maintain the pH of the system at 6~7. After the aluminum nitrate solution is added dropwise over 1~2 hours, continue stirring and reacting for 2~3 hours. After filtration and drying, calcine at 600~700℃ for 3~4 hours to obtain the insulating and thermally conductive additive.

2. The insulating flame-retardant tape according to claim 1, characterized in that, The release liner is one or more of polyethylene, polypropylene, and polyester; the antioxidants in the base film, flame retardant adhesive, and insulating adhesive are one or more of 168, 1010, and 1076; the lubricant in the base film is one or more of polyethylene wax, sodium stearate, and polyethylene glycol; the defoamer in the adhesive layer is one or more of BYK-021, BYK-028, and BYK-A530, and the leveling agent is one or more of ASK-191, LD-9601, and LB-575; the coupling agents in the flame retardant adhesive and insulating adhesive are one or more of KH-550, KH-560, KH-570, and KH-590; and the fillers in the flame retardant adhesive and insulating adhesive are one or more of fumed silica, calcium carbonate, and montmorillonite.

3. The insulating flame-retardant tape according to claim 1, characterized in that, The insulating material comprises, by weight, 30-50 parts of insulating and thermally conductive additive, 10-20 parts of anisole, 20-30 parts of boron nitride ceramic powder, 50-60 parts of epoxy resin, and 20-40 parts of polyetheramine curing agent; the particle size of the boron nitride ceramic powder in S21 is between 10 and 20 μm.

4. The insulating flame-retardant tape according to claim 1, characterized in that, The insulating and thermally conductive additive consists of 5-10 parts by weight of synthetic diamond micro powder, 1-5 parts by weight of surfactant, 15-20 parts by weight of aluminum nitrate solution, and 100 parts by weight of deionized water; the particle size of the synthetic diamond micro powder in S31 is between 0.1 and 5 μm, and the surfactant is one or more combinations of sodium hexadecyl sulfonate, dodecyl alcohol polyoxyethylene ether, and lauramide propyl betaine.

5. The method for preparing an insulating flame-retardant tape according to claim 1, characterized in that, Includes the following steps: S1. Preparation of base film layer: Weigh the materials used for the base film layer, add the weighed materials to a high-speed mixer and mix for 10~20 minutes, then add to an extruder for extrusion and calendering, controlling the thickness to 0.2~0.5 mm to obtain the base film layer; S2. Preparation of adhesive layer material: Weigh the materials used for the adhesive layer, dilute the hydroxyl acrylic resin and methacrylic resin in deionized water, add leveling agent and defoamer and stir evenly to obtain the adhesive layer material; S3. Preparation of adhesive paste: Weigh the materials used for flame retardant adhesive layer and insulating adhesive layer respectively. Mix the materials used for flame retardant adhesive layer and insulating adhesive layer evenly, and then mix them through a two-roll mill and a mixing mill to produce sheets. Crush and granulate, add organic solvent, and stir at 70~85℃ until there is no gel-like solid. Let stand for 24 hours to obtain flame retardant adhesive paste and insulating adhesive paste. S4. Adhesive coating: After the base film layer is coated with adhesive material through the composite molding machine, flame retardant adhesive and insulating adhesive are coated in sequence, composite molding is performed, and the film is wound up by the guide roller. S5. Applying the release film layer: After cooling by rollers, the release film layer is applied, with the thickness controlled at 1.4~1.8mm. The tape is then wound up by a traction machine to obtain a large roll of insulating flame-retardant tape. S6. Cutting and Packaging: Place the large roll of insulating flame-retardant tape into a slitting machine to cut and package it to obtain the insulating flame-retardant tape product.

6. The method for preparing an insulating flame-retardant tape according to claim 5, characterized in that, In S1, the extruder feed temperature is 130~150℃, and the extrusion outlet temperature is 160~180℃; in S2, deionized water is added to dilute the acrylic resin to a total content of 30~50wt%; in S3, the organic solvent is one or more combinations of n-hexane, n-propanol, and isopropanol; the opening temperature of the flame-retardant adhesive layer is 120~150℃, and the mixing temperature is 140~160℃; the opening temperature of the insulating adhesive layer is 140~160℃, and the mixing temperature is 160~180℃.

Images