Coating material for optical fiber and method for producing the same, optical fiber insulator and method for producing the same

Abstract

The application discloses a coating material for optical fiber and a preparation method thereof, an optical fiber insulator and a preparation method thereof. The preparation raw material of the coating material comprises the following components in parts by weight: tetrahydrofuran acrylate 40-60 parts by weight, carboxyl modified polyurethane acrylate oligomer 30-50 parts by weight, silicone modified epoxy acrylate bifunctional linker 5-15 parts by weight, vinyl silane surface modified SiO2 nanoparticles 2-5 parts by weight, triaryl sulfonium hexafluoroantimonate cationic initiator 0.1-1 part by weight, and TPO free radical photoinitiator 0.5-4 parts by weight. According to the embodiment of the application, the silicone modified epoxy acrylate bifunctional linker in the coating layer realizes active chemical bonding between the optical fiber coating layer and the alicyclic epoxy resin sheath, reduces the physical gap and thermal stress mismatch of the multi-material interface, and thus can fundamentally improve the interface strength, internal insulation performance and long-term reliability of the optical fiber insulator.

Description

Technical Field

[0001] This application belongs to the field of optical fiber sensing technology and power equipment technology, and particularly relates to a coating material for optical fiber and its preparation method, and an optical fiber insulator and its preparation method. Background Technology

[0002] As voltage levels continue to rise, more stringent requirements are being placed on the insulation performance and reliability of power equipment. As a key component in power transmission and monitoring systems, the performance of fiber optic insulators directly affects the safe and stable operation of the power grid.

[0003] Currently, alicyclic epoxy resins, due to their excellent electrical insulation properties and mechanical strength, can be used as insulation materials for high-voltage optical fiber insulators. However, existing optical fiber coating materials on the market (such as acrylates and polyimides) are mainly geared towards low-voltage, low-electric-field scenarios. Furthermore, traditional optical fiber coatings have significant differences in thermal expansion coefficients and insufficient chemical compatibility with alicyclic epoxy resins. This makes it easy for physical micro-gaps to form between the coating and the sheath under long-term high voltage, high field strength, and temperature changes, leading to partial discharge and accelerated insulation performance degradation. Simultaneously, this thermal stress mismatch can also cause the coating to peel off from the sheath, damaging the overall structure of the optical fiber insulator and severely affecting its service life and reliability. Summary of the Invention

[0004] This application provides a coating material for optical fibers and its preparation method, as well as an optical fiber insulator and its preparation method. The specially made optical fiber coating material can be applied under high voltage and high electric field conditions, and the optical fiber insulator can be applied in 500kV-1100kV AC / DC environments. This is intended to at least solve the problems of physical micro-gap and thermal stress mismatch caused by poor interfacial compatibility between traditional coating layers and alicyclic epoxy resin sheaths in optical fiber insulators in related technologies.

[0005] In a first aspect, embodiments of this application provide a coating material for optical fibers, wherein the raw materials for preparing the coating material comprise the following components in parts by weight:

[0006] 40-60 parts by weight of tetrahydrofuran acrylate

[0007] 30-50 parts by weight of carboxyl-modified polyurethane acrylate oligomer,

[0008] 5-15 parts by weight of organosilicon-modified epoxy acrylate bifunctional binder

[0009] 2-5 parts by weight of vinylsilane-modified SiO2 nanoparticles.

[0010] 0.1-1 parts by weight of triarylthionium hexafluoroantimonate cationic initiator

[0011] 0.5 to 4 parts by weight of TPO free radical photoinitiator.

[0012] Optionally, the organosilicon-modified epoxy acrylate bifunctional linker contains acryloyloxy and epoxy groups.

[0013] Secondly, embodiments of this application provide a method for preparing a coating material for optical fibers as described in any embodiment of the first aspect, the method comprising the following steps:

[0014] S110. Tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomer are mixed to obtain a matrix resin solution.

[0015] S120. Under nitrogen protection, the matrix resin solution obtained in step S110 is mixed with the organosilicon-modified epoxy acrylate bifunctional binder, then vinyl silane surface-modified SiO2 nanoparticles are added and ultrasonically dispersed, and then mixed with triarylthionium hexafluoroantimonate cationic initiator and TPO free radical photoinitiator to obtain the coating material.

[0016] Optionally, in step S110, the tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomer are mixed under constant temperature of 50-70°C and stirring conditions of 400-600 r / min.

[0017] Optionally, in step S120, the mixture is prepared with the triarylthionium hexafluoroantimonate cationic initiator and the TPO free radical photoinitiator under light-protected conditions and with a stirring speed of 150-250 r / min.

[0018] Thirdly, embodiments of this application provide a method for fabricating an optical fiber insulator, the method comprising the following steps:

[0019] S210. Coating the optical fiber with the coating material as described in any embodiment of the first aspect;

[0020] S220. Attach the optical fiber to the surface of the core rod;

[0021] S230. An sheath and a shed are pressed onto the surface of the core rod using an injection molding process, so that the sheath and the shed are integrally formed on the surface of the core rod to obtain an optical fiber insulator; wherein, the sheath is an alicyclic epoxy resin sheath.

[0022] Optionally, step S210 includes:

[0023] Plasma activation treatment is applied to the surface of the optical fiber;

[0024] The coating material is applied to the surface of an optical fiber by high-speed drawing under nitrogen protection conditions.

[0025] UV curing is performed under ultraviolet light to form a preliminary coating with residual epoxy active groups.

[0026] Optionally, step S230 includes:

[0027] During the injection molding stage of the alicyclic epoxy resin sheath, the curing heat of the sheath is used to simultaneously trigger the ring-opening crosslinking reaction between the residual epoxy active groups and the sheath, thereby achieving covalent bonding between the coating layer and the sheath interface and the integrated molding of the interpenetrating network (IPN) structure.

[0028] Fourthly, embodiments of this application provide an optical fiber insulator, which is prepared using the optical fiber insulator preparation method described in any embodiment of the third aspect.

[0029] The fiber optic coating material and its preparation method, as well as the fiber optic insulator and its preparation method, of this application embodiment achieve active chemical bonding between the fiber optic coating layer and the alicyclic epoxy resin sheath through the organosilicon-modified epoxy acrylate bifunctional binder in the coating layer, reducing physical gaps and thermal stress mismatch at the multi-material interface; furthermore, the combination of vinyl silane-modified SiO2 nanoparticles to fill micropores and block the growth of electrical trees ensures that the signal loss increment after thermal cycling is far below the industry failure threshold; thereby fundamentally improving the interface strength, internal insulation performance, and long-term reliability of the fiber optic insulator. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic flowchart of a method for preparing a coating material for optical fibers provided in an embodiment of this application;

[0032] Figure 2 This is a schematic flowchart of a method for fabricating an optical fiber insulator provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the structure of an optical fiber insulator provided in an embodiment of this application.

[0034] Figure label:

[0035] Sheath 1, umbrella skirt 2, optical fiber 3, core rod 4. Detailed Implementation

[0036] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0038] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0039] Currently, fiber-optic composite insulators used in high-voltage power transmission face a severe interface failure problem. Significant differences in thermal expansion coefficients and insufficient chemical compatibility exist between traditional fiber coatings (such as acrylate or polyimide) and the alicyclic epoxy resin materials of the insulator sheath. This leads to microcracks and delamination at the coating-sheath interface under temperature cycling, humid environments, or mechanical stress. These interface defects not only disrupt the stability of fiber-optic sensing signals but also trigger partial discharge and insulation resistance degradation, causing a continuous decline in the insulator's internal insulation performance. Ultimately, this significantly shortens the equipment's service life, becoming a key bottleneck restricting the reliability of high-voltage power transmission systems.

[0040] To address the problems in related technologies, embodiments of this application provide a coating material for optical fibers and its preparation method, as well as an optical fiber insulator and its preparation method, relating to the fields of optical fiber sensing technology and power equipment technology.

[0041] This application upgrades the coating layer from a "passive protective layer" to an "active interface bonding layer" through material chemical bonding and process synergy, solving the core challenge of multi-material interface synergy. It aims to address the physical gaps, thermal stress mismatch, and process defects caused by poor interfacial compatibility between traditional coating layers and alicyclic epoxy resin sheaths in optical fiber insulators. By innovatively designing an organosilicon hybrid coating material with dual reactive groups (acryloyloxy and epoxy groups), combined with plasma activation pretreatment and UV / thermal dual-mode gradient curing, a basic protective structure is formed through free radical polymerization during the coating curing stage. During sheath thermal curing, a covalent bonding reaction is triggered between the residual epoxy groups in the coating layer and the alicyclic epoxy resin, simultaneously constructing an interpenetrating network interface structure. This completely eliminates physical gaps at the interface, suppresses the risk of thermal expansion peeling, and eliminates the leakage hazards of traditional filler adhesive processes. This significantly improves the interfacial strength, internal insulation withstand voltage, and long-term signal transmission stability of optical fiber insulators, meeting the requirements of high-voltage power grids for monitoring reliability and a lifespan of over 30 years.

[0042] The reagents or materials used in the following examples can all be purchased from conventional manufacturers. Specific manufacturers and models are shown in Table 1:

[0043] Table 1

[0044]

[0045] First, the coating material for optical fibers and its preparation method provided in this application will be described in detail through specific embodiments and application scenarios.

[0046] Examples 1-3

[0047] A coating material for optical fibers, the specific components of which are shown in Table 2, with the amount of each component expressed in "parts by weight":

[0048] Table 2

[0049]

[0050] Among them, the organosilicon-modified epoxy acrylate bifunctional linker has an acryloyloxy group and an epoxy group in its molecular structure.

[0051] refer to Figure 1 The preparation method of the coating material for optical fibers provided in Examples 1 to 3 may include the following steps S110 to S120:

[0052] S110. Tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomers are mixed to obtain a matrix resin solution.

[0053] In practice, tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomers are placed in a reaction vessel and thoroughly stirred and mixed at a constant temperature of 60°C and a rotation speed of 500 r / min to form a homogeneous and transparent solution.

[0054] S120. Under nitrogen protection, the matrix resin solution obtained in step S110 is mixed with the organosilicon-modified epoxy acrylate bifunctional binder, then vinyl silane surface-modified SiO2 nanoparticles are added and ultrasonically dispersed, and then mixed with triarylthionium hexafluoroantimonate cationic initiator and TPO free radical photoinitiator to obtain the coating material.

[0055] In practice, the steps include S121 to S123:

[0056] S121. Under nitrogen protection, add organosilicon-modified epoxy acrylate bifunctional linker and stir continuously for 30 minutes to ensure molecular-level dispersion and prevent epoxy group pre-reaction.

[0057] S122, Add vinylsilane surface-modified SiO2 nanoparticles, and eliminate agglomerates by ultrasonic dispersion for 20 minutes. The modified SiO2 is embedded in polymer chains during ultrasonic dispersion and migrates to the interface region during thermosetting to form a dual barrier of "pore filling + electric field homogenization".

[0058] S123. Under light-protected conditions, add triarylthionium hexafluoroantimonate cationic initiator and TPO free radical photoinitiator, stir at 200 r / min for 10 minutes until completely mixed, to obtain a functionalized hybrid coating material that can trigger dual-mode curing (UV polymerization + thermal ring-opening crosslinking).

[0059] The temperature, rotation speed, stirring time, and ultrasonic dispersion time parameters of S110, S121, S122, and S123 in Examples 1-3 are shown in Table 3 below:

[0060] Table 3

[0061]

[0062] Comparative Example 1

[0063] A coating material for optical fibers, which differs from Example 1 in that it does not contain a silicone-modified epoxy acrylate bifunctional binder, while the other components, dosages, and preparation methods are the same as in Example 1.

[0064] Comparative Example 2

[0065] A coating material for optical fibers, which differs from Example 1 in that it lacks vinylsilane surface-modified SiO2 nanoparticles, while the other components, amounts, and preparation methods are the same as in Example 1.

[0066] Comparative Example 3

[0067] A coating material for optical fibers, which differs from Example 1 in that the silicone-modified epoxy acrylate bifunctional binder is 25 parts by weight, while the other components, amounts, and preparation methods are the same as in Example 1.

[0068] Performance testing:

[0069] (1) Interface peel strength test: 90° peel test was adopted, the test speed was 50mm / min, the ambient temperature was 25℃, and each group of samples was tested 5 times and the average value was taken.

[0070] (2) Signal loss test after thermal cycling: 500 cycles (12 hours each) were performed in the range of -40℃ to 80℃, and the signal loss increment at a wavelength of 1550nm was measured using an optical time domain reflectometer (OTDR).

[0071] (3) Internal insulation breakdown voltage test: The oil immersion method was used, the voltage rise rate was 1kV / s, the ambient temperature was 25℃, the relative humidity was 50%, and the voltage value at the moment of breakdown was recorded.

[0072] (4) Electric tree growth inhibition test: A DC electric field of 10kV / mm was applied for 72 hours, and the length of the electric tree was observed through a microscope. Three parallel samples were tested for each group of samples.

[0073] The optical fiber coating materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested according to the above test methods. The test results are shown in Table 4.

[0074] Table 4

[0075]

[0076]

[0077] As shown in Table 4, the optical fiber coating material provided in this application exhibits superior interfacial bonding. The bifunctional binder can covalently bond with the alicyclic epoxy resin sheath, forming an interpenetrating network structure that significantly enhances interfacial peel strength. Regarding thermal stability, the vinyl silane-modified SiO2 nanoparticles fill micropores, blocking electrical tree growth paths and effectively suppressing thermal stress damage. In terms of insulation performance, the synergistic effect of the covalently bonded structure constructed by the bifunctional binder and the nanoparticles significantly improves the internal insulation breakdown voltage.

[0078] Specifically, comparing Example 1, Comparative Example 1, and Comparative Example 2 reveals the following: Comparative Example 1, lacking a silicone-modified epoxy acrylate bifunctional binder, exhibits an interfacial peel strength of only 3.2 N / cm, significantly lower than Example 1's 8.6 N / cm; its signal loss increment after thermal cycling reaches 0.82 dB / km, 16.4 times that of Example 1; its internal insulation breakdown voltage is only 65 kV, less than half that of Example 1; and its maximum electrical tree length reaches 150 μm, 6 times that of Example 1. Comparative Example 2, lacking vinylsilane-modified SiO2 nanoparticles, has an interfacial peel strength of 6.8 N / cm, 79.1% of Example 1; its signal loss increment after thermal cycling is 0.35 dB / km, 7 times that of Example 1; its internal insulation breakdown voltage is 92 kV, only 71.9% of Example 1; and its maximum electrical tree length is 80 μm, 3.2 times that of Example 1. This indicates that organosilicon-modified epoxy acrylate bifunctional binders and vinyl silane-modified SiO2 nanoparticles play an important role in improving the performance of optical fiber coating materials.

[0079] Comparing Examples 1, 2, and 3 reveals that the material properties change with increasing amounts of the organosilicon-modified epoxy acrylate bifunctional binder and the vinyl silane surface-modified SiO2 nanoparticles. Example 2 exhibits an interfacial peel strength of 9.2 N / cm, higher than Example 1's 8.6 N / cm and Example 3's 8.9 N / cm; a signal loss increment after thermal cycling of 0.04 dB / km, lower than Example 1's 0.05 dB / km and Example 3's 0.06 dB / km; an internal insulation breakdown voltage of 135 kV, higher than Example 1's 128 kV and Example 3's 130 kV; and a maximum electrical tree length of 20 μm, lower than Example 1's 25 μm and Example 3's 22 μm. This indicates that, within a certain range, increasing the amount of these two core materials can further optimize the material properties.

[0080] Comparing Example 1 and Comparative Example 3, it can be found that the amount of silicone-modified epoxy acrylate bifunctional binder added in Comparative Example 3 exceeds the set range. Its interfacial peel strength is 5.1 N / cm, lower than 8.6 N / cm in Example 1; the signal loss increase after thermal cycling is 0.58 dB / km, 11.6 times that of Example 1; the internal insulation breakdown voltage is 80 kV, only 62.5% of that in Example 1; and the maximum electrical tree length is 110 μm, 4.4 times that of Example 1. This indicates that the amount of silicone-modified epoxy acrylate bifunctional binder added needs to be controlled within a reasonable range; exceeding this range will lead to a decrease in material performance.

[0081] Therefore, by using the organosilicon-modified epoxy acrylate bifunctional binder in the coating layer, active chemical bonding between the optical fiber coating layer and the alicyclic epoxy resin sheath can be achieved, reducing physical gaps and thermal stress mismatch at the multi-material interface. Furthermore, by combining vinyl silane-modified SiO2 nanoparticles to fill micropores and block the growth of electrical trees, the signal loss increment after thermal cycling is far below the industry failure threshold. This fundamentally improves the interfacial strength, internal insulation performance, and long-term reliability of optical fiber insulators.

[0082] Furthermore, this application also provides a method for fabricating an optical fiber insulator. It should be noted that this method for fabricating an optical fiber insulator can be applied to the optical fiber coating material as described in any of the above embodiments.

[0083] It is understandable that, as a key carrier of power transmission line monitoring systems, optical fiber insulators have significant interfacial compatibility issues between the traditional coating layer of the internal optical fiber and the alicyclic epoxy resin material of the outer sheath. This leads to weak physical bonding and lack of chemical bonding, causing interfacial micro-gaps and exacerbating the risk of surface discharge. At the same time, the difference in the thermal expansion coefficients of the materials induces interfacial peeling and moisture intrusion under alternating temperature conditions, accelerating interface degradation and affecting the stability of optical fiber signal transmission.

[0084] In addition, existing coating processes have defects such as insufficient curing and poor coating uniformity. The passive solution that relies on filler adhesive to compensate for interface gaps is prone to local electric field distortion, which ultimately leads to a decrease in the insulation performance of the insulator, a reduction in mechanical strength, and an inability to meet the long-term operation requirements of high-voltage power grids.

[0085] Figure 2 A schematic flowchart illustrating the fabrication method of an optical fiber insulator according to an embodiment of this application is shown. Figure 2 As shown, the fabrication method of this optical fiber insulator may specifically include the following steps:

[0086] S210. Coat the optical fiber with the coating material prepared in any of the above embodiments;

[0087] S220. Attach the optical fiber to the surface of the core rod;

[0088] S230. An sheath and a shed are pressed onto the surface of the core rod using an injection molding process, so that the sheath and the shed are integrally formed on the surface of the core rod to obtain an optical fiber insulator; wherein, the sheath is an alicyclic epoxy resin sheath.

[0089] The specific implementation methods for each of the above steps are described below.

[0090] In some embodiments, in S210, the surface of the optical fiber is subjected to plasma activation treatment; the coating material is coated on the surface of the optical fiber by high-speed drawing under nitrogen protection; and UV curing is performed under ultraviolet light to form a preliminary coating with residual epoxy active groups.

[0091] In practice, the surface of the bare optical fiber is first treated with argon / oxygen low-temperature plasma to generate highly active silanol groups (-Si-OH); then, a hybrid coating material is applied under nitrogen protection, and the initial UV curing is completed by UV-triggered free radical polymerization to form a pre-cured coating with epoxy active groups.

[0092] In this way, plasma pretreatment generates silanol groups (-Si-OH), which improves the adhesion of the optical fiber coating. Dual-mode gradient curing is adopted, with UV curing under nitrogen protection to avoid oxidation interference. Chemical bonding is triggered during the heat curing stage of the sheath, eliminating the risk of leakage. Modified SiO2 nanoparticles are introduced to improve the density and resistance to electrical tracking of the coating.

[0093] In some embodiments, in S220, the optical fiber is wound around the surface of the core rod, so that the optical fiber is attached to the cylindrical surface of the core rod.

[0094] In some embodiments, in S230, during the injection molding stage of the alicyclic epoxy resin sheath, the curing heat of the sheath is used to simultaneously trigger the ring-opening crosslinking reaction between the residual epoxy active groups and the sheath, thereby achieving covalent bonding between the coating layer and the sheath interface and the integrated molding of the interpenetrating network (IPN) structure.

[0095] In this way, the organosilicon-modified epoxy acrylate bifunctional binder (containing acryloyloxy and epoxy groups) in the coating layer undergoes ring-opening polymerization with the alicyclic epoxy resin during the sheath thermosetting stage (150–180℃), forming a covalently bonded "molecular bridge" structure, which completely eliminates interfacial micro-gaps and prevents surface discharge.

[0096] Therefore, by employing a synergistic process of plasma activation-gradient curing (UV initial curing + thermal synergistic curing), the residual epoxy groups in the coating layer are triggered to crosslink with the sheath resin during sheath molding, forming an interpenetrating network (IPN) structure, which synchronously matches the thermal expansion behavior of both and inhibits peeling.

[0097] Therefore, this application embodiment designs an organosilicon hybrid resin containing dual reactive groups (acryloyloxy and epoxy) as the core component of the coating layer. During the coating stage, a basic protective layer is formed by photocuring, and the epoxy ring-opening reaction is triggered during the subsequent thermal curing of the sheath alicyclic epoxy resin, realizing the direct covalent bond connection between the coating layer and the sheath interface. Simultaneously, plasma surface activation pretreatment and staged gradient curing process are combined to eliminate physical gaps at the interface and construct an integrated interpenetrating network structure. Functional nanofillers are used to enhance the density of the coating, fundamentally solving the reliability problems caused by poor interface compatibility, thermal stress mismatch and process defects, and significantly improving the interface strength, electrical resistance and long-term stability of the insulator.

[0098] In addition, this application also provides an optical fiber insulator. It should be noted that the optical fiber insulator in this application embodiment is manufactured using the optical fiber insulator manufacturing method of any of the above embodiments.

[0099] refer to Figure 3 This is a schematic diagram of the structure of an optical fiber insulator according to an embodiment of this application. Figure 3 As shown, the optical fiber insulator consists of four parts: core rod 4, optical fiber 3, sheath 1, and shed 2.

[0100] In summary, the embodiments of this application propose a high-interface-stability optical fiber insulator coating material and preparation method, as well as a coating process for a special optical fiber coating material for optical fiber composite insulators. The aim is to eliminate physical gaps at the interface and construct an integrated interpenetrating network structure by optimizing the interfacial chemical bonding between the optical fiber coating and the sheath alicyclic epoxy resin through innovative coating material design and process optimization, based on the molecular bridging chemical bonding mechanism. This significantly improves the internal insulation performance and long-term stability of the insulator and enables online monitoring. Specifically, through material formulation innovation (organosilicon-epoxy hybrid acrylate system) and process breakthroughs (plasma activation-gradient curing synergy), the coating layer has been upgraded from a "passive protective layer" to an "actively bonded functional layer," solving the long-standing problem of multi-material interface synergistic failure between the optical fiber coating layer and the sheath. Its core disruptiveness lies in: molecular-level interface design, with bifunctional binders achieving covalent bond bridging between the coating layer and the sheath, breaking through the limitations of traditional physical adhesion; process-material synergy, with plasma activation and gradient curing forming an integrated interpenetrating network, simultaneously optimizing thermal matching and density; and full life cycle improvement, from interface strength and electrical resistance to signal stability, systematically meeting the stringent requirements of ultra-high voltage power grids for monitoring reliability.

[0101] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0102] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0103] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0104] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0105] In this application, "multiple" means two or more (including two).

[0106] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0107] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0108] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for fabricating an optical fiber insulator, characterized in that, The method includes the following steps: S210. Apply the coating material to the optical fiber; S220. Attach the optical fiber to the surface of the core rod; S230. An sheath and a shed are pressed onto the surface of the core rod using an injection molding process, so that the sheath and the shed are integrally formed on the surface of the core rod to obtain an optical fiber insulator; wherein, the sheath is an alicyclic epoxy resin sheath. The raw materials for preparing the coating material include the following components in parts by weight: 40-60 parts by weight of tetrahydrofuran acrylate 30-50 parts by weight of carboxyl-modified polyurethane acrylate oligomer, 5-15 parts by weight of organosilicon-modified epoxy acrylate bifunctional binder 2-5 parts by weight of vinylsilane surface-modified SiO2 nanoparticles 0.1-1 parts by weight of triarylthionium hexafluoroantimonate cationic initiator 0.5-4 parts by weight of TPO free radical photoinitiator; The organosilicon-modified epoxy acrylate bifunctional linker contains acryloyloxy and epoxy groups.

2. The method for preparing an optical fiber insulator according to claim 1, characterized in that, The preparation method of the coating material includes the following steps: S110. Tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomer are mixed to obtain a matrix resin solution. S120. Under nitrogen protection, the matrix resin solution obtained in step S110 is mixed with the organosilicon-modified epoxy acrylate bifunctional binder, then vinyl silane surface-modified SiO2 nanoparticles are added and ultrasonically dispersed, and then mixed with triarylthionium hexafluoroantimonate cationic initiator and TPO free radical photoinitiator to obtain the coating material.

3. The method for preparing an optical fiber insulator according to claim 2, characterized in that, In step S110, tetrahydrofuran acrylate and carboxyl-modified polyurethane acrylate oligomers are mixed under constant temperature of 50-70°C and stirring conditions of 400-600 r / min.

4. The method for preparing an optical fiber insulator according to claim 2, characterized in that, In step S120, the mixture is prepared by mixing the triarylthionium hexafluoroantimonate cationic initiator and the TPO free radical photoinitiator under light-protected conditions and stirring at a speed of 150-250 r / min.

5. The method for preparing an optical fiber insulator according to claim 1, characterized in that, Step S210 includes: Plasma activation treatment is applied to the surface of the optical fiber; The coating material is applied to the surface of an optical fiber by high-speed drawing under nitrogen protection conditions. UV curing is performed under ultraviolet light to form a preliminary coating with residual epoxy active groups.

6. The method for preparing an optical fiber insulator according to claim 1, characterized in that, Step S230 includes: During the injection molding stage of the alicyclic epoxy resin sheath, the curing heat of the sheath is used to simultaneously trigger the ring-opening crosslinking reaction between the residual epoxy active groups and the sheath, thereby achieving covalent bonding between the coating layer and the sheath interface and the integrated molding of the interpenetrating network (IPN) structure.

7. An optical fiber insulator, characterized in that, It is prepared by the method for preparing optical fiber insulators as described in any one of claims 1-6.

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