Low-shrinkage optical cable sheath material and preparation method thereof

Abstract

The invention discloses a low-shrinkage optical cable sheath material and a preparation method thereof.The preparation method comprises the steps that epoxy amino reaction components and nano TiO2 are evenly dispersed in a shearing stirrer, a non-amino catalyst is slowly added into nano filler, stirring is continuously conducted to enable the non-amino catalyst to be evenly distributed, then a silane functional surfactant is added, stirring is conducted continuously, and the low-shrinkage optical cable sheath material is obtained. Slowly and sequentially adding an anti-ultraviolet hydrogel and an antioxidant into the pre-mixed system, mixing a special chain extender with a cross-linking agent, adding the mixture into the mixture system to promote the cross-linking reaction, and gradually adding a pre-prepared epoxy prepolymer into the mixture system to form a reaction system with a network structure with high cross-linking density; and injecting the mixture into an optical cable sheath mold, and then carrying out curing treatment to obtain the low-shrinkage optical cable sheath material. Through innovative material components and optimized process steps, the performance of the optical cable sheath material is comprehensively improved, and the requirements for low-shrinkage and high-durability materials in outdoor high-temperature and high-ultraviolet specific scenes are met.

Description

Technical Field

[0001] The invention relates to a field, and in particular to a low-shrinkage optical cable sheath material and a preparation method thereof. Background Art

[0002] With the rapid development of modern communication technology, the application scope of optical cables, as the core infrastructure of information transmission, has been continuously expanded, covering many fields such as urban communication networks, data center interconnection, wide area network construction, and various industrial control systems. Especially in outdoor environments, optical cable sheath materials need to withstand the long-term effects of high temperature, high ultraviolet radiation, and harsh weather conditions. These special application scenarios put forward higher performance requirements for optical cable sheath materials, especially low shrinkage, excellent weather resistance, and long-term mechanical strength, to ensure the stable operation of optical cables in complex environments and extend their service life.

[0003] At present, the common optical cable sheath materials on the market mainly adopt the traditional polyurethane foam system. This type of material performs well in conventional application environments and has good flexibility and mechanical strength. However, in special outdoor environments with high temperature and high sun, traditional polyurethane sheath materials have significant shrinkage problems. This shrinkage not only causes stress concentration in the internal structure of the optical cable, affecting the quality of signal transmission, but may also cause cracking and aging of the sheath material, shortening the service life of the optical cable. In addition, traditional materials are prone to degradation under high ultraviolet radiation, resulting in rapid degradation of physical properties, further limiting their application in extreme environments.

[0004] Therefore, the existing technology cannot effectively meet the requirements of low shrinkage and high durability of optical cable sheath materials in outdoor high temperature and high sunlight environments. It is urgent to develop innovative sheath material preparation methods with excellent low shrinkage performance and excellent weather resistance to improve the reliability and service life of optical cables in special application scenarios. Summary of the invention

[0005] The purpose of the present invention is to provide a low-shrinkage optical cable sheath material and a preparation method thereof to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions: A method for preparing a low-shrinkage optical cable sheath material, comprising: Step S1, weighing epoxy amino reaction components, non-amine catalysts, silane functional surfactants, anti-ultraviolet hydrogels, special chain extenders, crosslinking agents, nano-TiO2 and antioxidants according to a preset ratio; uniformly dispersing the epoxy amino reaction components and nano-TiO2 in a shear mixer to obtain uniform nanofillers; Step S2, slowly adding the non-amine catalyst to the nanofiller, continuously stirring to uniformly distribute the non-amine catalyst, then adding a silane functional surfactant, and further stirring the mixture to form a premixed system; Step S3, during the stirring process, slowly adding the anti-ultraviolet hydrogel and the antioxidant to the premixed system in sequence to complete the integration of the functional additives to form a mixture system; Step S4, after mixing the special chain extender and the cross-linking agent, adding them to the mixture system, controlling the reaction temperature at 60° C. to promote the cross-linking reaction, and then gradually adding the pre-prepared epoxy prepolymer to the mixture system to make it fully react with other components to form a reaction system with a network structure with a high cross-linking density; Step S5, injecting the reaction system into the optical cable sheath mold, and performing a curing treatment for 2 hours at a preset temperature and pressure to make the material completely cross-linked and achieve low shrinkage performance, then gradually cooling to room temperature, demolding and performing quality inspection to obtain a low shrinkage optical cable sheath material.

[0007] Optionally, the epoxy reactive component is an epoxy reactive agent having an average functionality of 2.0-2.5 and a polyol derivative having a molecular weight higher than 600 g / mol.

[0008] Optionally, the step S2 specifically includes: Step S21, under the condition that the stirring temperature is controlled at 25°C to 30°C, a high shear rate stirring device is used to start stirring at an initial stirring speed of 500 rpm; Step S22, slowly and gradually adding the non-amine catalyst to the pre-uniformly dispersed nanofiller suspension at a preset constant rate through a constant flow feeding device; Step S23, using an online particle size analyzer to monitor the dispersion state of the nanofiller in real time, and adjusting the stirring rate according to the monitoring results to maintain the shear force in the range of 1000 to 1500 S⁻¹.

[0009] Optionally, after step S23, the following steps are further included: Step S24, when the non-amine catalyst is completely dispersed, slowly adding the silane functional surfactant at a rate of 2 grams per minute, while keeping the stirring speed unchanged, so that the surfactant is evenly distributed in the system; Step S25, during the process of adding the silane functional surfactant, a phased addition strategy is adopted, first adding 50% of the silane functional surfactant, stirring for 10 minutes, and then adding the remaining 50% of the silane functional surfactant; Step S26, after the surfactant is added, continue mixing at a stirring speed of 500 rpm for at least 30 minutes to form a premixed system with a uniform nanofiller dispersion state and a stable catalyst and surfactant distribution.

[0010] Optionally, the step S3 specifically includes: Step S31, transferring the premixed system to a reaction vessel equipped with a temperature control and high shear stirring device, ensuring that the stirring temperature is maintained between 30°C and 35°C; Step S32, using a constant flow feeding system, slowly adding the anti-ultraviolet hydrocoagulant to the premixed system in batches at a constant rate of 3 grams per minute, adding 1 gram each time in three times, and stirring continuously for 5 minutes after each addition; Step S33, after the anti-ultraviolet hydrocoagulant is completely dispersed, the feed rate is adjusted to 2 grams per minute, and the antioxidant is slowly added in two portions of 1 gram each time, and stirring is continued for 5 minutes after each addition to ensure stable integration of the antioxidant; Step S34, during the process of adding the antioxidant, an online spectrometer is used to monitor the ultraviolet absorption characteristics in the system in real time, so that the effective dispersion concentration of the anti-ultraviolet hydrocoagulant reaches a desired value; Step S35, using a detector to perform particle size analysis on the mixture system after adding the functional additive, so that the particle diameter is maintained at a preset nanometer level; Step S36, after the addition is completed, continue to stir the mixture system for at least 15 minutes to allow the anti-ultraviolet hydrogel and antioxidant to fully blend with other components in the premixed system to form a stable mixture system.

[0011] Optionally, the step S4 specifically includes: Step S41, in a premixing system, a special chain extender and a crosslinking agent are weighed in an equimolar ratio, and the special chain extender and the crosslinking agent are placed in a dry reaction container under the protection of an inert gas for premixing; Step S42, slowly adding the mixed special chain extender and cross-linking agent into the mixture system in a segmented manner, with the amount added each time not exceeding 20% ​​of the total amount; Step S43, during the addition process, start the constant temperature water bath system, gradually raise the temperature of the reaction container to 60°C, and then maintain the temperature at 60°C; Step S44: At the same time, a high shear rate stirrer is used to continuously stir the mixture system at a stirring speed of 800 rpm to uniformly disperse the special chain extender and the cross-linking agent in the mixture system.

[0012] Optionally, after step S44, the following steps may be further performed: Step S45, after the special chain extender and the cross-linking agent are completely mixed and evenly dispersed, slowly start the gradual addition process of the pre-prepared epoxy prepolymer, using a constant flow feeding device, adding the epoxy prepolymer in batches at a rate of 4 grams per minute, with the amount added each time not exceeding 10% of the total amount, and continue stirring for 10 minutes after each addition; Step S46, during the addition of the epoxy prepolymer, real-time monitoring of the viscosity change of the reaction system, and using an online viscometer to ensure that the viscosity is within a preset range; Step S47, using an infrared spectrometer to analyze the reaction system in real time to monitor the progress of the cross-linking reaction, so that the reaction between the epoxy group and the amino group is complete and a preset cross-linking density is achieved; Step S48, after all components have been added and fully reacted, continue stirring at 60° C. for at least 45 minutes to form a reaction system with a network structure having a high cross-linking density.

[0013] Optionally, the pre-preparation process of the epoxy prepolymer is: Step S401, weighing a preset ratio of epoxy resin, curing agent, and reaction aid; Step S402, adding the weighed epoxy resin and curing agent into the reaction container in proportion, starting the stirrer, and performing preliminary mixing at a stirring speed of 500 rpm, and continuing stirring for 30 minutes; during the stirring process, gradually adding the reaction aid, adding 0.2 grams per minute, so that the reaction aid is evenly distributed; Step S403, start the heating system, slowly raise the temperature of the mixture in the reaction container to 80°C, keep stirring the reaction under constant temperature, and promote the partial cross-linking reaction between the epoxy resin and the curing agent; react at 80°C for 2 hours, and adjust the stirring rate to 700 rpm; Step S404, using a viscometer to monitor the viscosity change of the mixture in real time, and when the viscosity reaches a predetermined value, it is confirmed that part of the cross-linking reaction has been completed to form a preliminary epoxy prepolymer; Step S405, after the reaction is completed, slowly turn off the heating system, and continue to stir the mixture at room temperature for at least 30 minutes, remove unreacted solid impurities from the prepared epoxy prepolymer through a filtering device, and transfer the filtered epoxy prepolymer to a storage container.

[0014] The present invention also provides a low-shrinkage optical cable sheath material, which is prepared by the method for preparing the low-shrinkage optical cable sheath material as described above, and the components of the low-shrinkage optical cable sheath material include: Epoxyamino reactive component, mass fraction is 40%; TiO2, mass fraction is 1-10%; Non-amine catalyst, mass fraction is 0.5-5%; Silane functional surfactant, mass fraction is 0.1-2%; Anti-ultraviolet hydrogel, mass fraction is 0.5-3%; Antioxidant, mass fraction is 0.2-1.5%; Special chain extender, mass fraction is 2-8%; Cross-linking agent, mass fraction is 1-6%; Epoxy prepolymer, mass fraction is 10-20%.

[0015] Compared with the prior art, the present invention has the following beneficial effects: firstly, the epoxyamino reaction component and nano-TiO2 are uniformly dispersed in a high-shear mixer to form a nano-filler with good dispersibility; a stable premixed system is formed by slowly adding a non-amine catalyst and a silane functional surfactant, and the distribution and interface stability of the catalyst are optimized; an anti-ultraviolet hydrogel and an antioxidant are further integrated into the premixed system to enhance the anti-ultraviolet and anti-oxidation properties of the material, and improve its durability in a high-temperature and high-ultraviolet environment; by adding a special chain extender and a crosslinking agent, and gradually introducing an epoxy prepolymer, the formation of a high-crosslinking density network structure is promoted at a controlled temperature, and the thermal stability and low shrinkage performance of the material are significantly improved; the reaction system is injected into a mold for curing treatment; through strict temperature and pressure control, the complete crosslinking and low shrinkage characteristics of the material are achieved, and a low-shrinkage optical cable sheath material is obtained; the method comprehensively improves the performance of the optical cable sheath material through innovative material components and optimized process steps, and meets the demand for low-shrinkage and high-durability materials in specific outdoor high-temperature and high-ultraviolet scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0018] Figure 1 This is one of the flow diagrams of the method for preparing the low-shrinkage optical cable sheath material of the first embodiment; Figure 2This is the second flow chart of the method for preparing the low-shrinkage optical cable sheath material of the first embodiment. DETAILED DESCRIPTION

[0019] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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.

[0020] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0021] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0022] Embodiment 1: Combination Figure 1 to Figure 2 As shown, an embodiment of the present invention provides a method for preparing a low-shrinkage optical cable sheath material, comprising: Step S1, weighing epoxy amino reaction components, non-amine catalysts, silane functional surfactants, anti-ultraviolet hydrogels, special chain extenders, crosslinking agents, nano-TiO2 and antioxidants according to preset proportions; uniformly dispersing the epoxy amino reaction components and nano-TiO2 in a shear mixer to obtain uniform nanofillers.

[0023] Step S2, slowly adding the non-amine catalyst to the nanofiller, continuously stirring to evenly distribute the non-amine catalyst, then adding the silane functional surfactant, and further stirring the mixture to form a premixed system.

[0024] Step S3, during the stirring process, slowly add the anti-ultraviolet hydrogel agent and the antioxidant to the premixed system in sequence to complete the integration of the functional additives and form a mixture system.

[0025] Step S4, after mixing the special chain extender and the cross-linking agent, add them to the mixture system, control the reaction temperature at 60°C to promote the cross-linking reaction, and then gradually add the pre-prepared epoxy prepolymer to the mixture system to make it fully react with other components to form a reaction system with a network structure with a high cross-linking density.

[0026] Step S5, injecting the reaction system into the optical cable sheath mold, and performing a curing treatment for 2 hours at a preset temperature and pressure to make the material completely cross-linked and achieve low shrinkage performance, then gradually cooling to room temperature, demolding and performing quality inspection to obtain a low shrinkage optical cable sheath material.

[0027] The working principle of the present invention is as follows: first, epoxy amino reaction components and nano-TiO2 are uniformly dispersed in a high shear mixer to form a nano-filler with good dispersibility, and a non-amine catalyst and a silane functional surfactant are slowly added to form a stable premixed system to optimize the distribution and interface stability of the catalyst; further, an anti-ultraviolet hydrogel and an antioxidant are integrated into the premixed system to enhance the anti-ultraviolet and anti-oxidation properties of the material and improve its durability in a high-temperature and high-ultraviolet environment; by adding a special chain extender and a crosslinking agent, and gradually introducing an epoxy prepolymer, the formation of a high-crosslinking density network structure is promoted at a controlled temperature, and the thermal stability and low shrinkage performance of the material are significantly improved; the reaction system is injected into a mold for curing treatment, and through strict temperature and pressure control, the complete crosslinking and low shrinkage characteristics of the material are achieved to obtain a low-shrinkage optical cable sheath material; the method comprehensively improves the performance of the optical cable sheath material through innovative material components and optimized process steps, and meets the demand for low-shrinkage and high-durability materials in specific outdoor high-temperature and high-ultraviolet scenarios.

[0028] In this embodiment, it is specifically described that the epoxy reactive component is an epoxy reactive agent having an average functionality of 2.0-2.5 and a polyol derivative having a molecular weight higher than 600 g / mol.

[0029] In this embodiment, it is specifically described that step S2 specifically includes: Step S21, under the condition that the stirring temperature is controlled at 25°C to 30°C, a high shear rate stirring device is used to start stirring at an initial stirring speed of 500 rpm; Step S22, slowly and gradually adding the non-amine catalyst to the pre-uniformly dispersed nanofiller suspension at a preset constant rate through a constant flow feeding device; During the addition of the non-amine catalyst, stirring was continued for at least 20 minutes to ensure uniform distribution of the catalyst in the nanofiller and to prevent excessive local concentration of the catalyst; Step S23, using an online particle size analyzer to monitor the dispersion state of the nanofiller in real time, and adjusting the stirring rate according to the monitoring results to maintain the shear force in the range of 1000 to 1500 S⁻¹ to promote sufficient dispersion of the catalyst.

[0030] Step S24, after the non-amine catalyst is completely dispersed, slowly add the silane functional surfactant at a rate of 2 grams per minute while keeping the stirring speed constant to ensure uniform distribution of the surfactant in the system.

[0031] Step S25, during the addition of the silane functional surfactant, a phased addition strategy is adopted, first adding 50% of the silane functional surfactant, stirring for 10 minutes and then adding the remaining 50% of the silane functional surfactant to prevent excessive aggregation of the surfactant.

[0032] Step S26, after the surfactant is added, continue mixing at a stirring speed of 500 rpm for at least 30 minutes to form a premixed system with a uniform nanofiller dispersion state and a stable catalyst and surfactant distribution.

[0033] During the entire process of step S2, a temperature control system is used to maintain the system temperature between 25°C and 30°C to prevent excessive reaction or uneven dispersion of components due to temperature fluctuations.

[0034] In this embodiment, it is specifically described that step S3 specifically includes: Step S31, transferring the premixed system to a reaction vessel equipped with a temperature control and high shear stirring device, ensuring that the stirring temperature is maintained between 30°C and 35°C to optimize the dissolution and dispersion of the functional additive; Step S32, using a constant flow feeding system, slowly adding the anti-UV hydrocoagulant in batches to the premixed system at a constant rate of 3 grams per minute, adding 1 gram each time in three times, and stirring continuously for 5 minutes after each addition to ensure uniform distribution of the anti-UV hydrocoagulant.

[0035] Step S33, after the anti-ultraviolet hydrocoagulant is completely dispersed, the feeding rate is adjusted to 2 grams per minute, and the antioxidant is slowly added in two portions of 1 gram each time, and stirring is continued for 5 minutes after each addition to ensure stable integration of the antioxidant.

[0036] Step S34, during the process of adding the antioxidant, an online spectrometer is used to monitor the ultraviolet absorption characteristics in the system in real time, so that the effective dispersion concentration of the anti-ultraviolet hydrocoagulant reaches a desired value.

[0037] Step S35, using a detector to perform particle size analysis on the mixture system after adding the functional additive, so that the particle diameter is maintained at a preset nanometer level (less than 100 nanometers) to improve the uniformity and performance of the material.

[0038] During the entire addition and stirring process, the stirring rate was kept constant at 800 rpm to provide sufficient shear force (about 1200 s⁻¹) to promote the full dispersion of functional additives while avoiding excessive shearing that would lead to a decrease in system stability; A temperature recorder is used to monitor the temperature change in the reaction container in real time to ensure that the temperature of the entire step S3 is always maintained between 30°C and 35°C to prevent aggregation or decomposition of additives caused by temperature fluctuations.

[0039] Step S36, after the addition is completed, continue to stir the mixture system for at least 15 minutes to allow the anti-ultraviolet hydrogel and antioxidant to fully blend with other components in the premixed system to form a stable mixture system.

[0040] The final mixture system should show good transparency and uniformity, without obvious precipitation or phase separation, to ensure the effective dispersion and performance improvement of the functional additives in the low-shrinkage optical cable sheath material; In this embodiment, it is specifically described that step S4 specifically includes: Step S41, in a premixed system, weigh a special chain extender and a crosslinking agent in an equimolar ratio, and place the special chain extender and the crosslinking agent in a dry reaction container under the protection of an inert gas for premixing; and fully mix them in a mass ratio of 1:1.

[0041] Step S42, slowly adding the mixed special chain extender and cross-linking agent into the mixture system in a segmented manner, with the amount added each time not exceeding 20% ​​of the total amount to prevent uneven reaction caused by excessive local concentration.

[0042] Step S43, during the adding process, start the constant temperature water bath system, gradually raise the temperature of the reaction container to 60°C, and then maintain the temperature at 60°C to ensure that the cross-linking reaction is carried out at the optimal temperature.

[0043] Step S44: At the same time, a high shear rate stirrer is used to continuously stir the mixture system at a stirring speed of 800 rpm to uniformly disperse the special chain extender and the cross-linking agent in the mixture system to promote their reaction activity.

[0044] Step S45, after the special chain extender and the cross-linking agent are completely mixed and evenly dispersed, slowly start the gradual addition process of the pre-prepared epoxy prepolymer, use a constant flow feeding device, add the epoxy prepolymer in batches at a rate of 4 grams per minute, and the amount added each time shall not exceed 10% of the total amount, and continue stirring for 10 minutes after each addition to ensure that the epoxy prepolymer reacts fully with other components.

[0045] Step S46, during the addition of the epoxy prepolymer, the viscosity change of the reaction system is monitored in real time, and an online viscometer is used to ensure that the viscosity is within a preset range (500 to 700 mPa·s) to prevent excessive thickening or insufficient reaction.

[0046] Step S47, using an infrared spectrometer to perform real-time analysis on the reaction system to monitor the progress of the cross-linking reaction, so that the reaction between the epoxy group and the amino group is complete and a preset cross-linking density is achieved.

[0047] Step S48, after all components have been added and fully reacted, continue stirring at 60°C for at least 45 minutes to form a reaction system with a network structure with a high cross-linking density to enhance the mechanical strength and heat resistance of the material.

[0048] Finally, through the temperature recorder and stirring rate monitoring system, it is confirmed that the temperature of the reaction system is stable and the stirring is uniform during the entire step S4, ensuring the formation of a high cross-linking density network structure, providing an ideal reaction basis for the subsequent curing step; The reaction system after forming a high cross-linking density network structure is transferred to a predetermined reaction container to prepare for the next step of curing treatment.

[0049] In this embodiment, it is specifically described that the pre-preparation process of the epoxy prepolymer is: Step S401, weighing a preset ratio of epoxy resin (e.g., bisphenol A epoxy resin), a curing agent (e.g., dioctyl adipate), and a reaction aid (e.g., tert-butyl phosphonate); Step S402, add the weighed epoxy resin and curing agent into the reaction container in proportion, start the agitator, perform preliminary mixing at a stirring speed of 500 rpm, and continue stirring for 30 minutes; during the stirring process, gradually add the reaction aid, adding 0.2 grams per minute to ensure uniform distribution of the reaction aid.

[0050] Step S403, start the heating system, slowly raise the temperature of the mixture in the reaction container to 80°C, maintain the reaction under constant temperature conditions and stir to promote the partial cross-linking reaction between the epoxy resin and the curing agent; react at 80°C for 2 hours, and adjust the stirring rate to 700 rpm.

[0051] Step S404, using a viscometer to monitor the viscosity change of the mixture in real time, when the viscosity reaches a predetermined value (about 1500 mPa·s), it is confirmed that part of the cross-linking reaction has been completed to form a preliminary epoxy prepolymer.

[0052] Step S405, after the reaction is completed, slowly turn off the heating system, and continue to stir the mixture at room temperature for at least 30 minutes, remove unreacted solid impurities from the prepared epoxy prepolymer through a filtering device, and transfer the filtered epoxy prepolymer to a storage container.

[0053] Embodiment 2: A low-shrinkage optical cable sheath material, characterized in that it is prepared by the preparation method of the low-shrinkage optical cable sheath material according to any one of claims 1 to 8, and the components of the low-shrinkage optical cable sheath material include: Epoxyamino reactive component, mass fraction is 40%; TiO2, mass fraction is 1-10%; Non-amine catalyst, mass fraction is 0.5-5%; silane functional surfactant, mass fraction is 0.1-2%; anti-UV hydrogel, mass fraction is 0.5-3%; antioxidant, mass fraction is 0.2-1.5%; special chain extender, mass fraction is 2-8%; cross-linking agent, mass fraction is 1-6%; epoxy prepolymer, mass fraction is 10-20%.

[0054] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a low-shrinkage optical cable sheath material, characterized in that: include: Step S1, weighing epoxy amino reaction components, non-amine catalysts, silane functional surfactants, anti-ultraviolet hydrogels, special chain extenders, crosslinking agents, nano-TiO2 and antioxidants according to a preset ratio; uniformly dispersing the epoxy amino reaction components and nano-TiO2 in a shear mixer to obtain uniform nanofillers; Step S2, slowly adding the non-amine catalyst to the nanofiller, continuously stirring to uniformly distribute the non-amine catalyst, then adding a silane functional surfactant, and further stirring the mixture to form a premixed system; Step S3, during the stirring process, slowly adding the anti-ultraviolet hydrogel and the antioxidant to the premixed system in sequence to complete the integration of the functional additives to form a mixture system; Step S4, after mixing the special chain extender and the cross-linking agent, adding them to the mixture system, controlling the reaction temperature at 60° C. to promote the cross-linking reaction, and then gradually adding the pre-prepared epoxy prepolymer to the mixture system to make it fully react with other components to form a reaction system with a network structure with a high cross-linking density; Step S5, injecting the reaction system into the optical cable sheath mold, and performing a curing treatment for 2 hours at a preset temperature and pressure to make the material completely cross-linked and achieve low shrinkage performance, then gradually cooling to room temperature, demolding and performing quality inspection to obtain a low shrinkage optical cable sheath material.

2. The method for preparing a low shrinkage optical cable sheath material according to claim 1, characterized in that: The epoxy reactive component is an epoxy reactive agent with an average functionality of 2.0-2.5 and a polyol derivative with a molecular weight higher than 600 g / mol.

3. The method for preparing a low shrinkage optical cable sheath material according to claim 1, characterized in that: The step S2 specifically includes: Step S21, under the condition that the stirring temperature is controlled at 25°C to 30°C, a high shear rate stirring device is used to start stirring at an initial stirring speed of 500 rpm; Step S22, slowly and gradually adding the non-amine catalyst to the pre-uniformly dispersed nanofiller suspension at a preset constant rate through a constant flow feeding device; Step S23, using an online particle size analyzer to monitor the dispersion state of the nanofiller in real time, and adjusting the stirring rate according to the monitoring results to maintain the shear force in the range of 1000 to 1500 S⁻¹.

4. The method for preparing a low shrinkage optical cable sheath material according to claim 3, characterized in that: After step S23, the following steps are also included: Step S24, when the non-amine catalyst is completely dispersed, slowly adding the silane functional surfactant at a rate of 2 grams per minute, while keeping the stirring speed unchanged, so that the surfactant is evenly distributed in the system; Step S25, during the process of adding the silane functional surfactant, a phased addition strategy is adopted, first adding 50% of the silane functional surfactant, stirring for 10 minutes, and then adding the remaining 50% of the silane functional surfactant; Step S26, after the surfactant is added, continue mixing at a stirring speed of 500 rpm for at least 30 minutes to form a premixed system with a uniform nanofiller dispersion state and a stable catalyst and surfactant distribution.

5. The method for preparing a low shrinkage optical cable sheath material according to claim 1, characterized in that: The step S3 specifically includes: Step S31, transferring the premixed system to a reaction vessel equipped with a temperature control and high shear stirring device, ensuring that the stirring temperature is maintained between 30°C and 35°C; Step S32, using a constant flow feeding system, slowly adding the anti-ultraviolet hydrocoagulant to the premixed system in batches at a constant rate of 3 grams per minute, adding 1 gram each time in three times, and stirring continuously for 5 minutes after each addition; Step S33, after the anti-ultraviolet hydrocoagulant is completely dispersed, the feed rate is adjusted to 2 grams per minute, and the antioxidant is slowly added in two portions of 1 gram each time, and stirring is continued for 5 minutes after each addition to ensure stable integration of the antioxidant; Step S34, during the process of adding the antioxidant, an online spectrometer is used to monitor the ultraviolet absorption characteristics in the system in real time, so that the effective dispersion concentration of the anti-ultraviolet hydrocoagulant reaches a desired value; Step S35, using a detector to perform particle size analysis on the mixture system after adding the functional additive, so that the particle diameter is maintained at a preset nanometer level; Step S36, after the addition is completed, continue to stir the mixture system for at least 15 minutes to allow the anti-ultraviolet hydrogel and antioxidant to fully blend with other components in the premixed system to form a stable mixture system.

6. The method for preparing a low shrinkage optical cable sheath material according to claim 1, characterized in that: The step S4 specifically includes: Step S41, in a premixing system, a special chain extender and a crosslinking agent are weighed in an equimolar ratio, and the special chain extender and the crosslinking agent are placed in a dry reaction container under the protection of an inert gas for premixing; Step S42, slowly adding the mixed special chain extender and cross-linking agent into the mixture system in a segmented manner, with the amount added each time not exceeding 20% ​​of the total amount; Step S43, during the addition process, start the constant temperature water bath system, gradually raise the temperature of the reaction container to 60°C, and then maintain the temperature at 60°C; Step S44: At the same time, a high shear rate stirrer is used to continuously stir the mixture system at a stirring speed of 800 rpm to uniformly disperse the special chain extender and the cross-linking agent in the mixture system.

7. The method for preparing a low shrinkage optical cable sheath material according to claim 6, characterized in that: After step S44, the following steps are also included: Step S45, after the special chain extender and the cross-linking agent are completely mixed and evenly dispersed, slowly start the gradual addition process of the pre-prepared epoxy prepolymer, using a constant flow feeding device, adding the epoxy prepolymer in batches at a rate of 4 grams per minute, with the amount added each time not exceeding 10% of the total amount, and continue stirring for 10 minutes after each addition; Step S46, during the addition of the epoxy prepolymer, real-time monitoring of the viscosity change of the reaction system, and using an online viscometer to ensure that the viscosity is within a preset range; Step S47, using an infrared spectrometer to analyze the reaction system in real time to monitor the progress of the cross-linking reaction, so that the reaction between the epoxy group and the amino group is complete and a preset cross-linking density is achieved; Step S48, after all components have been added and fully reacted, continue stirring at 60° C. for at least 45 minutes to form a reaction system with a network structure having a high cross-linking density.

8. The method for preparing a low-shrinkage optical cable sheath material according to claim 7, characterized in that: The pre-preparation process of the epoxy prepolymer is: Step S401, weighing a preset ratio of epoxy resin, curing agent, and reaction aid; Step S402, adding the weighed epoxy resin and curing agent into the reaction container in proportion, starting the stirrer, performing preliminary mixing at a stirring speed of 500 rpm, and continuing stirring for 30 minutes; During the stirring process, the reaction aid was gradually added at a rate of 0.2 g per minute to ensure that the reaction aid was evenly distributed; Step S403, start the heating system, slowly raise the temperature of the mixture in the reaction container to 80°C, keep stirring the reaction under constant temperature, and promote the partial cross-linking reaction between the epoxy resin and the curing agent; react at 80°C for 2 hours, and adjust the stirring rate to 700 rpm; Step S404, using a viscometer to monitor the viscosity change of the mixture in real time, and when the viscosity reaches a predetermined value, it is confirmed that part of the cross-linking reaction has been completed to form a preliminary epoxy prepolymer; Step S405, after the reaction is completed, slowly turn off the heating system, and continue to stir the mixture at room temperature for at least 30 minutes, remove unreacted solid impurities from the prepared epoxy prepolymer through a filtering device, and transfer the filtered epoxy prepolymer to a storage container.

9. A low shrinkage optical cable sheath material, characterized in that: The low-shrinkage optical cable sheath material is prepared by the preparation method of any one of claims 1 to 8, wherein the components of the low-shrinkage optical cable sheath material include: Epoxyamino reactive component, mass fraction is 40%; TiO2, mass fraction is 1-10%; Non-amine catalyst, mass fraction is 0.5-5%; Silane functional surfactant, mass fraction is 0.1-2%; Anti-ultraviolet hydrogel, mass fraction is 0.5-3%; Antioxidant, mass fraction is 0.2-1.5%; Special chain extender, mass fraction is 2-8%; Cross-linking agent, mass fraction is 1-6%; Epoxy prepolymer, mass fraction is 10-20%.

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