CN113088168B

CN113088168B - High-hardness optical fiber cladding coating and preparation method thereof

Info

Publication number: CN113088168B
Application number: CN202110299820.5A
Authority: CN
Inventors: 沈亚汝; 郑超; 王朝磊
Original assignee: Shanghai Xianquan Optical Fiber Technology Co ltd
Current assignee: Shanghai Xianquan Optical Fiber Technology Co ltd
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2021-11-05
Anticipated expiration: 2041-03-22
Also published as: CN113088168A

Abstract

The invention discloses a high-hardness optical fiber cladding coating and a preparation method thereof. The optical fiber cladding coating raw material comprises the following components: by weight, 45-55 parts of polyethylene glycol acrylate, 38-42 parts of trimethylpropane triacrylate, 2-3 parts of mercaptotrimethylsilane, 10-15 parts of composite nano filler, 1.2-1.5 parts of bacterial cellulose, 1-1.5 parts of photoinitiator and 0.05-0.1 part of compatilizer. (1) The interaction of hydrogen bonds of the bacterial cellulose and polyethylene glycol branched chains in the polyethylene glycol acrylate is utilized to crosslink with the tri-functional trimethylpropane triacrylate, so that a rich crosslinking network is generated, and the hardness is obviously enhanced and improved. (2) The method is characterized in that a Michael addition reaction is utilized to graft butyl acrylate on hexagonal hollow silica to form a soft shell core, methyl methacrylate is utilized to generate a hard shell by self polymerization, and the interface compatibility, the low refractive index and the fracture toughness are obviously enhanced.

Description

High-hardness optical fiber cladding coating and preparation method thereof

Technical Field

The invention relates to the technical field of optical fiber coatings, in particular to a high-hardness optical fiber cladding coating and a preparation method thereof.

Background

The optical fiber cladding coating is a coating which can protect quartz glass fiber from external environment and has excellent mechanical strength and optical performance. The selection of the coating for the cladding is particularly important due to the complicated conditions and methods for preparing the optical fiber. Among thermosetting, thermoplastic and other coating types, the ultraviolet curing type coating is the first choice for the optical fiber cladding coating because of its green, pollution-free and fast curing speed.

The hardness of the optical fiber coating which is commercialized in the market is not comparable to that of the commonly used glass cladding material, and the hardness problem causes the problem of the flatness of the cut end face when the high-rise optical fiber is cut. One reason for the low hardness is that the photoinitiator is a small molecular substance, and is easy to cause migration or volatilization, so that the photocuring is non-uniform, and the curing is incomplete; in addition, although functional materials such as inorganic materials are usually added to the coating material to increase the hardness of the coating material, the compatibility between the inorganic materials and the coating material matrix affects the refractive index, and thus there is a problem that the energy of the coating layer leaks out. Therefore, the preparation of the high-hardness optical fiber cladding coating is of great significance.

Disclosure of Invention

The invention aims to provide a high-hardness optical fiber cladding coating and a preparation method thereof, so as to solve the problems in the background technology.

In order to solve the technical problems, the invention provides the following technical scheme:

a high-hardness optical fiber cladding coating material, wherein the raw material of the optical fiber cladding coating material comprises the following components: 45-55 parts of polyethylene glycol acrylate, 38-42 parts of trimethylpropane triacrylate, 2-3 parts of mercaptotrimethylsilane, 10-15 parts of composite nano filler, 1.2-1.5 parts of bacterial cellulose, 1-1.5 parts of photoinitiator and 0.05-0.1 part of compatilizer by weight; the photoinitiator comprises 80-90 wt% of load type photoinitiator and 10-20 wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone.

Preferably, the particle size of the composite nano filler is 100-180 nm.

Preferably, the composite nano filler is a nano particle taking aminated silica nano particles/butyl acrylate as a shell core and methyl methacrylate as an outer shell.

Preferably, the raw materials of the supported photoinitiator comprise the following components: 6-12 parts of 2-chlorothioxanthone and 5-10 parts of aminated silicon dioxide nanoparticles by weight.

Preferably, the aminated silica nanoparticles are hexagonal hollow structures.

Preferably, the preparation method of the high-hardness optical fiber cladding coating comprises the following steps:

step 1: preparation of silica nanoparticles: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles into an ethanol solution, adding an ammonia water solution, and stirring; slowly adding tetraethoxysilane, reacting, centrifugally separating, washing and drying; transferring the solution into a hydrochloric acid solution, stirring for reaction, changing the solution from milky white to transparent, washing and filtering to obtain the silicon dioxide nano particles with the hexagonal hollow structures for later use;

step 2: ultrasonically dispersing silicon dioxide nanoparticles in an ethanol solution, adding a 3-aminopropyltriethoxysilane coupling agent aqueous solution, setting the reaction temperature to be 60-70 ℃, reacting for 7-9 hours, filtering, washing and drying to obtain aminated silicon dioxide nanoparticles;

and step 3: preparation of supported photoinitiator: sequentially dispersing the aminated silicon dioxide nano particles and 2-chlorothioxanthone in a toluene solution, stirring, mixing, reacting, filtering, washing and drying to obtain a supported photoinitiator;

and 4, step 4: preparing the composite nano filler: weighing aminated silica nanoparticles, butyl acrylate and methyl methacrylate according to a proportion for later use; sequentially adding the aminated silicon dioxide nanoparticles, 4-sodium dodecyl sulfate and an ethanol-water solution into a reaction kettle, and stirring for 15-30 minutes; slowly dripping 5% butyl acrylate at 60-100 ℃, setting the reaction time to be 4-8 hours, and cooling; slowly adding the rest 95% of butyl acrylate for 2-2.5 hours; adding an ammonium persulfate solution and a sodium formaldehyde sulfoxylate solution which are in a molar ratio of 1:1 as initiators for 3-3.5 hours; reacting for 50-60 minutes to obtain silicon dioxide nano particles/poly (butyl acrylate); sequentially and slowly adding methyl methacrylate and tert-butyl hydroperoxide for 2.5-3 hours and 3.5-4 hours respectively; reacting for 60-80 minutes, filtering, washing and drying to obtain the composite nano filler;

and 5: preparing the optical fiber cladding coating: mixing polyethylene glycol acrylate, trimethylpropane triacrylate and mercapto-trimethylsilane, setting the stirring speed to be 800-1000 rmp, heating to 75-85 ℃, and stirring for 20-40 minutes; sequentially adding the composite nano filler, the bacterial cellulose and the compatilizer, continuously stirring for 15-30 minutes, and shearing for 5-8 minutes; and cooling to 48-52 ℃, adding 80-90 wt% of load type photoinitiator and 10-20 wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone, and stirring for 30-40 minutes to obtain the optical fiber cladding coating.

Preferably, the specific process of step 1 is as follows: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles in an ethanol solution containing PVP, adding an ammonia water solution, and stirring for 10-20 minutes at room temperature; slowly adding tetraethoxysilane, reacting for 4-5 hours, centrifugally separating, washing and drying; and transferring the solution into 0.2-0.22M hydrochloric acid solution, stirring and reacting for 5-6 hours, changing the solution from milky white to transparent, washing and filtering to obtain the silicon dioxide nano particles with the hexagonal hollow structures.

Preferably, the specific process of step 3 is as follows: sequentially dispersing the aminated silicon dioxide nano particles and 2-chlorothioxanthone in a toluene solution, and stirring and mixing for 30-50 minutes; and (3) reacting for 6-8 hours at the temperature of 60-70 ℃, filtering, washing and drying to obtain the supported photoinitiator.

Preferably, in the step 4, the molar ratio of the aminated silica nanoparticles to the butyl acrylate to the methyl methacrylate is (1: 4: 5) - (1: 8: 10).

Preferably, in the step 4, the temperature for cooling is 70-75 ℃.

According to the technical scheme, polyethylene glycol acrylate is used as a main body, trimethylpropane triacrylate is used as an active diluent, mercaptotrimethylsilane is introduced to increase the adhesive force, bacterial cellulose is added to increase the hardness, and a composite nano filler is introduced to increase the elongation at break and the low refractive index performance. The mixed photoinitiator is adopted and is cured into a cladding under the ultraviolet condition, and the prepared coating has the advantages of fast curing, uniform curing, high hardness, low refractive index and the like.

The polyethylene glycol acrylate is a linear polymer with acrylate and polyethylene glycol bifunctional groups, the bacterial cellulose is a polymer with a unique three-dimensional structure and has flexibility and biocompatibility, the polyethylene glycol acrylate can be self-rotated and diffused in the three-dimensional structure of the bacterial cellulose, and a staggered three-dimensional network is generated after cross-linking, so that the generated network has high rigidity and high hardness; the polyethylene glycol branched chain on the polyethylene glycol acrylate can generate intermolecular hydrogen bond interaction with the hydrogen bond on the bacterial cellulose, so that the bacterial cellulose has certain elasticity, and the storage stability of the coating is improved. However, when the content is too high and the hardness is too high, brittleness occurs and cracks easily occur, and therefore, it is necessary to control the amount of the bacterial cellulose to be added to suppress brittleness. Under the ration, the coating has high hardness, stronger compression deformation resistance and certain elasticity.

Meanwhile, the tri-functional trimethylolpropane triacrylate has high activity, low volatility, hardness adhesive force, good compatibility with acrylic substances, unsaturated bonds with polyethylene glycol acrylate, crosslinking under the action of a photoinitiator to generate abundant crosslinking networks and increase hardness. And the sulfydryl in the mercaptopropyl trimethoxy silane can generate thiol-ene click reaction with unsaturated bonds, and is embedded in a cross-linked network, so that the cross-linking abundance is increased, and the adhesion capacity of the coating and the optical fiber is increased. And the content of unsaturated bond compounds needs to be controlled, the oligomeric chains are easily entangled because there may be an excess of olefin moieties that are incompletely cured, reducing the conversion of carbon-carbon double bonds.

In addition, hollow hexagonal silica nanoparticles were prepared using hexagonal zinc oxide as a template. Firstly, the addition of the silicon dioxide nano particles increases the hardness of the coating, has extremely strong absorption characteristic to ultraviolet rays, improves the curing rate, increases the double bond conversion rate and solves the defect of incomplete curing of the ubiquitous acrylic resin coating. Secondly, the hexagonal shape enables the surface energy to be higher and the optical activity to be better; the hollow structure reduces the density and the weight of the coating, and the hexagonal hollow structure enables the coating to have lower refractive index, thereby inhibiting the energy leakage of the coating, and the refractive index is about 1.36.

Meanwhile, in order to increase the compatibility and dispersibility of the inorganic nanoparticles and the polypropylene coating, butyl acrylate is grafted by utilizing the Michael addition reaction, and is used as a central core, a soft shell core is generated by self-polymerization, and a hard shell is generated by self-polymerization of methyl methacrylate, so that the composite nano-filler is formed; the soft shell core can be uniformly distributed in a cross-linked network through a cross-linking process to increase interface compatibility, and meanwhile, because the particles in the soft shell core are hexagonal, gaps can be generated, and when stress is concentrated, a multi-axial stress field can be formed, so that the particles are subjected to bond removal and stress dispersion. Therefore, the composite nano filler prepared by the method can effectively enhance the fracture toughness of the cladding.

In addition, the supported photoinitiator replaces most of the commonly used 2-hydroxy-2-methyl-1-phenyl-1-propanone. Because the photoinitiator has mobility and volatility, the traditional photosensitizer 2-chlorothioxanthone is loaded on the nano particles, so that the volatilization of the photoinitiator and the migration to the outer surface of a cladding can be inhibited, and the silica nano particles with a loading mechanism absorb ultraviolet light, increase the conversion rate of carbon-carbon double bonds and complete curing. Meanwhile, the prepared load type photosensitive hair dye has hexagonal hollow silicon dioxide, so that the load type photosensitive hair dye and the composite nano filler generate a synergistic effect to enhance the hardness and the low refractivity. It also improves the interfacial interaction between the coating and the nanoparticles due to the loading of 2-chlorothioxanthone.

Compared with the prior art, the invention has the following beneficial effects: (1) by utilizing the interaction of hydrogen bonds of the bacterial cellulose and polyethylene glycol branched chains in the polyethylene glycol acrylate and the crosslinking between the bacterial cellulose and trifunctional trimethylpropane triacrylate, a rich crosslinking network is generated, and the hardness is improved. (2) Thiol-ene click reaction is generated by using thiol in mercaptopropyl trimethoxy silane and unsaturated bonds, and the thiol-ene click reaction is embedded in a cross-linked network, so that the cross-linked abundance is increased, and the adhesion capability of the coating and the optical fiber is increased. (3) The composite nano-filler is obtained by grafting butyl acrylate on hexagonal hollow silica through Michael addition reaction, forming a 'soft shell core' through self-polymerization of the butyl acrylate, and generating a 'hard shell' through self-polymerization of methyl methacrylate on the surface of the butyl acrylate, so that the interface compatibility, the low refractive index and the fracture toughness are obviously enhanced. (4) The prepared load type photoinitiator replaces most of 2-hydroxy-2-methyl-1-phenyl-1-acetone, inhibits the migration and volatilization of the micromolecule photoinitiator, enhances the conversion of carbon-carbon double bonds, and increases the curing speed and the curing effect.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

step 1: preparation of silica nanoparticles: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles in an ethanol solution containing PVP, adding an ammonia water solution, and stirring for 15 minutes at room temperature; slowly adding tetraethoxysilane, reacting for 4.5 hours, centrifugally separating, washing and drying; transferring the solution into 0.21M hydrochloric acid solution, stirring and reacting for 5.6 hours, changing the solution from milky white to transparent, washing and filtering to obtain silicon dioxide nano particles with hexagonal hollow structures for later use;

step 2: ultrasonically dispersing silicon dioxide nano particles in an ethanol solution, adding a 3-aminopropyltriethoxysilane coupling agent aqueous solution, setting the reaction temperature to 65 ℃ and the reaction time to 7.5 hours, filtering, washing and drying to obtain aminated silicon dioxide nano particles;

and step 3: preparation of supported photoinitiator: sequentially dispersing 8 parts of aminated silicon dioxide nano particles and 9 parts of 2-chlorothioxanthone in a toluene solution, and stirring and mixing for 40 minutes; setting the temperature to 65 ℃ for reaction for 7 hours, filtering, washing and drying to obtain a supported photoinitiator;

and 4, step 4: preparing the composite nano filler: weighing aminated silica nanoparticles, butyl acrylate and methyl methacrylate according to the molar ratio of 1:6:8 for later use; sequentially adding the aminated silicon dioxide nano particles, 4-sodium dodecyl sulfate and an ethanol-water solution into a reaction kettle, and stirring for 22 minutes; slowly dripping 5% butyl acrylate at 80 ℃, setting the reaction time to be 6 hours, and cooling to 72 ℃; slowly adding the rest 95% of butyl acrylate for 2.25 hours; adding an ammonium persulfate solution and a sodium formaldehyde sulfoxylate solution which are in a molar ratio of 1:1 as initiators for 3.25 hours; reacting for 55 minutes to obtain silicon dioxide nano particles/poly butyl acrylate; slowly adding methyl methacrylate and tert-butyl hydroperoxide in sequence for 2.8 hours and 3.8 hours respectively; reacting for 70 minutes, filtering, washing and drying to obtain the composite nano filler;

and 5: preparing the optical fiber cladding coating: mixing 50 parts of polyethylene glycol acrylate, 40 parts of trimethylpropane triacrylate and 2.5 parts of mercaptotrimethylsilane, setting the stirring speed to 900rmp, heating to 80 ℃, and stirring for 30 minutes; sequentially adding 12 parts of composite nano filler, 1.35 parts of bacterial cellulose and 0.08 part of compatilizer, continuously stirring for 22 minutes, and shearing for 6 minutes; cooling to 50 ℃, adding 1.25 parts of photosensitive initiator comprising 85wt% of supported photoinitiator and 15 wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone, and stirring for 35 minutes to obtain the optical fiber cladding coating.

Example 2:

step 1: preparation of silica nanoparticles: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles in an ethanol solution containing PVP, adding an ammonia water solution, and stirring for 10 minutes at room temperature; slowly adding tetraethoxysilane, reacting for 4 hours, centrifugally separating, washing and drying; transferring the solution into 0.2M hydrochloric acid solution, stirring and reacting for 5 hours, changing the solution from milky white to transparent, washing and filtering to obtain silicon dioxide nano particles with hexagonal hollow structures for later use;

step 2: ultrasonically dispersing silicon dioxide nano particles in an ethanol solution, adding a 3-aminopropyltriethoxysilane coupling agent aqueous solution, setting the reaction temperature to be 60 ℃, reacting for 7 hours, filtering, washing and drying to obtain aminated silicon dioxide nano particles;

and step 3: preparation of supported photoinitiator: dispersing 5 parts of aminated silicon dioxide nano particles and 6 parts of 2-chlorothioxanthone in a toluene solution in sequence, and stirring and mixing for 30 minutes; setting the temperature to be 60 ℃ for reaction for 6 hours, filtering, washing and drying to obtain a supported photoinitiator;

and 4, step 4: preparing the composite nano filler: weighing aminated silica nanoparticles, butyl acrylate and methyl methacrylate according to the molar ratio of 1:4:5 for later use; sequentially adding the aminated silicon dioxide nano particles, 4-sodium dodecyl sulfate and an ethanol-water solution into a reaction kettle, and stirring for 15 minutes; slowly dripping 5% butyl acrylate at 60-100 ℃, setting the reaction time to be 4 hours, and cooling to 70 ℃; slowly adding the rest 95% of butyl acrylate for 2 hours; adding an ammonium persulfate solution and a sodium formaldehyde sulfoxylate solution which are in a molar ratio of 1:1 as initiators for 3 hours; reacting for 50 minutes to obtain silicon dioxide nano particles/poly butyl acrylate; slowly adding methyl methacrylate and tert-butyl hydroperoxide in sequence for 2.5 hours and 3.5 hours respectively; reacting for 60 minutes, filtering, washing and drying to obtain the composite nano filler;

and 5: preparing the optical fiber cladding coating: mixing 45 parts of polyethylene glycol acrylate, 38 parts of trimethylpropane triacrylate and 2 parts of mercaptotrimethylsilane, setting the stirring speed to be 800rmp, heating to 75 ℃, and stirring for 20 minutes; sequentially adding 10 parts of composite nano filler, 1.2 parts of bacterial cellulose and 0.05 part of compatilizer, continuously stirring for 15 minutes, and shearing for 5 minutes; cooling to 48 ℃, adding 1 part of photosensitive initiator comprising 80wt% of supported photoinitiator and 20wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone, and stirring for 30 minutes to obtain the optical fiber cladding coating.

Example 3:

step 1: preparation of silica nanoparticles: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles in an ethanol solution containing PVP, adding an ammonia water solution, and stirring for 20 minutes at room temperature; slowly adding tetraethoxysilane, reacting for 5 hours, centrifugally separating, washing and drying; transferring the solution into 0.22M hydrochloric acid solution, stirring and reacting for 6 hours, changing the solution from milky white to transparent, washing and filtering to obtain silicon dioxide nano particles with hexagonal hollow structures for later use;

step 2: ultrasonically dispersing silicon dioxide nano particles in an ethanol solution, adding a 3-aminopropyltriethoxysilane coupling agent aqueous solution, setting the reaction temperature to be 70 ℃, reacting for 9 hours, filtering, washing and drying to obtain aminated silicon dioxide nano particles;

and step 3: preparation of supported photoinitiator: sequentially dispersing 10 parts of aminated silicon dioxide nano particles and 12 parts of 2-chlorothioxanthone in a toluene solution, and stirring and mixing for 50 minutes; setting the temperature to 70 ℃ for reaction for 8 hours, filtering, washing and drying to obtain a supported photoinitiator;

and 4, step 4: preparing the composite nano filler: weighing aminated silica nanoparticles, butyl acrylate and methyl methacrylate according to the molar ratio of 1:8:10 for later use; sequentially adding the aminated silicon dioxide nano particles, 4-sodium dodecyl sulfate and an ethanol-water solution into a reaction kettle, and stirring for 30 minutes; slowly dripping 5% butyl acrylate at 100 ℃, setting the reaction time to be 8 hours, and cooling to 75 ℃; slowly adding the rest 95% of butyl acrylate for 2.5 hours; adding an ammonium persulfate solution and a sodium formaldehyde sulfoxylate solution which are in a molar ratio of 1:1 as initiators for 3.5 hours; reacting for 60 minutes to obtain silicon dioxide nano particles/poly butyl acrylate; slowly adding methyl methacrylate and tert-butyl hydroperoxide in sequence for 3 hours and 4 hours respectively; reacting for 80 minutes, filtering, washing and drying to obtain the composite nano filler;

and 5: preparing the optical fiber cladding coating: mixing 55 parts of polyethylene glycol acrylate, 2 parts of trimethylpropane triacrylate and 3 parts of mercaptotrimethylsilane, setting the stirring speed to 1000rmp, heating to 85 ℃, and stirring for 40 minutes; sequentially adding 15 parts of composite nano filler, 1.5 parts of bacterial cellulose and 0.1 part of compatilizer, continuously stirring for 30 minutes, and shearing for 8 minutes; cooling to 52 ℃, adding 1.5 parts of photosensitive initiator comprising 90wt% of supported photoinitiator and 10wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone, and stirring for 40 minutes to obtain the optical fiber cladding coating.

Example 4: no bacterial cellulose is added; the rest is the same as in example 1.

Example 5: replacing the hexagonal hollow silica nanoparticles with the round hollow silica nanoparticles; the rest is the same as in example 1.

Example 6: hexagonal hollow silica nano particles are directly added without coating a shell layer; the rest is the same as in example 1.

Example 7: adding a hexagonal hollow silica grafted butyl acrylate soft shell core without coating a hard shell; the rest is the same as in example 1.

Example 8: the same procedure as in example 1 was repeated except that the photocatalyst was directly added without being supported.

Experiment:

coating the high-hardness optical fiber cladding coating prepared in the embodiment 1-8 on a quartz glass plate, irradiating by using an ultraviolet lamp, curing to form a film, and characterizing the basic performance: (1) testing the hardness of the alloy by referring to a GB/T6739-2006 standard method; (2) measuring the refractive index of the coating by using an Abbe refractometer, measuring the refractive index in three points, and taking an average value; (3) testing the elongation at break of the coating by adopting a universal mechanical testing instrument according to a T1731-93 standard method; (4) testing the adhesive force of the coating by referring to a GB/T5210-198 standard method, and testing the adhesive force of the coating by adopting a pull-off method adhesive force measuring instrument; specific experimental data are shown in the following table:

and (4) conclusion: from the data of examples 1 to 3, it can be seen that: the prepared optical fiber cladding coating has high hardness which can reach 5H, the refractive index can be as low as 1.366, certain flexibility is realized while the high hardness is maintained, the elongation at break can reach 130%, the adhesion is better 5B, and the coating is a high-strength optical fiber cladding coating.

Comparing the data from example 4 with example 1, it can be seen that: without the addition of bacterial cellulose coating, the hardness decreased and the elongation at break increased due to: the polyethylene glycol acrylate can be self-spun and diffused in a three-dimensional structure of the bacterial cellulose, so that a staggered three-dimensional network is generated after cross-linking, and the generated network has high rigidity and high hardness.

Comparing the data from example 5 with example 1, it can be seen that: the hardness is reduced, the refractive index is reduced, and the elongation at break is not obviously increased. The reason is that: the hexagonal hollow silica nano particle has better low refractive index and better photocatalytic activity, can assist a photosensitive initiator to increase the conversion rate of carbon-carbon double bonds and generate a denser crosslinking network, thereby increasing the hardness. Because the particles in the soft shell core are hexagonal, gaps can be generated, and when stress is concentrated, a multiaxial stress field can be formed, so that the particles are subjected to bond removal, and stress is dispersed. Therefore, the composite nano filler prepared by the method can effectively enhance the fracture toughness of the cladding, so that the fracture elongation rate is basically not changed, the crosslinking degree is reduced, and the fracture elongation rate is increased.

Comparing the data from example 6 with example 1, it can be seen that: the hardness and elongation at break decrease simultaneously, the refractive index increases, because: the non-coating shell results in poor compatibility, increases the refractive index, and generates a delamination phenomenon such that the elongation at break is reduced and the hardness is reduced due to the reduction of the crosslinking degree. This can be confirmed again by the data from example 7.

Comparing the data from example 8 with example 1, it can be seen that: the hardness is reduced because the supported photoinitiator replaces most of 2-hydroxy-2-methyl-1-phenyl-1-acetone, the migration and volatilization of the micromolecule photoinitiator can be effectively inhibited, the conversion of carbon-carbon double bonds is enhanced, and the curing speed and the curing effect are increased.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-hardness optical fiber cladding coating is characterized in that: the optical fiber cladding coating raw material comprises the following components: 45-55 parts of polyethylene glycol acrylate, 38-42 parts of trimethylpropane triacrylate, 2-3 parts of mercaptotrimethylsilane, 10-15 parts of composite nano filler, 1.2-1.5 parts of bacterial cellulose, 1-1.5 parts of photoinitiator and 0.05-0.1 part of compatilizer by weight; the photoinitiator comprises 80-90 wt% of load type photoinitiator and 10-20 wt% of 2-hydroxy-2-methyl-1-phenyl-1-acetone;

the preparation method comprises the following steps:

2. The high-hardness optical fiber cladding coating according to claim 1, wherein: the particle size of the composite nano filler is 100-180 nm.

3. The high-hardness optical fiber cladding coating according to claim 1, wherein: the composite nano filler is a nano particle taking aminated silicon dioxide nano particles/butyl acrylate as a shell core and methyl methacrylate as an outer shell.

4. The high-hardness optical fiber cladding coating according to claim 1, wherein: the raw materials of the supported photoinitiator comprise the following components: 6-12 parts of 2-chlorothioxanthone and 5-10 parts of aminated silicon dioxide nanoparticles by weight.

5. The high-hardness optical fiber cladding coating according to any one of claims 3 to 4, wherein: the aminated silica nanoparticles are hexagonal hollow structures.

6. The high-hardness optical fiber cladding coating according to claim 1, wherein: the specific process of step 1 is as follows: taking hexagonal zinc oxide particles as a template, ultrasonically dispersing the hexagonal zinc oxide particles in an ethanol solution containing PVP, adding an ammonia water solution, and stirring for 10-20 minutes at room temperature; slowly adding tetraethoxysilane, reacting for 4-5 hours, centrifugally separating, washing and drying; and transferring the solution into 0.2-0.22M hydrochloric acid solution, stirring and reacting for 5-6 hours, changing the solution from milky white to transparent, washing and filtering to obtain the silicon dioxide nano particles with the hexagonal hollow structures.

7. The high-hardness optical fiber cladding coating according to claim 1, wherein: the specific process of step 3 is as follows: sequentially dispersing the aminated silicon dioxide nano particles and 2-chlorothioxanthone in a toluene solution, and stirring and mixing for 30-50 minutes; and (3) reacting for 6-8 hours at the temperature of 60-70 ℃, filtering, washing and drying to obtain the supported photoinitiator.

8. The high-hardness optical fiber cladding coating according to claim 1, wherein: in the step 4, the molar ratio of the aminated silica nanoparticles to the butyl acrylate to the methyl methacrylate is (1: 4: 5) - (1: 8: 10).

9. The high-hardness optical fiber cladding coating according to claim 1, wherein: in the step 4, the temperature for cooling is 70-75 ℃.