An adhesion promoter for optical fiber coatings, its preparation method and application

Abstract

This invention provides an adhesion promoter for optical fiber coatings, its preparation method, and its application. The optical fiber coating adhesion promoter comprises the following components in parts by weight: 20-25 parts modified epoxy resin, 4-7 parts epoxy acrylate, 12-16 parts modified filler, 32-38 parts propylene glycol methyl ether acetate, 13-18 parts isobutanol, 6-10 parts phosphoric acid, and 5-7 parts water. The preparation method of the modified epoxy resin is as follows: (1) Under a nitrogen atmosphere, the epoxy resin is heated to 135-140°C, and then N,N-dimethylbenzylamine is added. After holding at this temperature for 8-10 hours, a polyepoxy compound is obtained; (2) N-methylethanolamine and amino-terminated liquid nitrile rubber are added sequentially to the polyepoxy compound. After reacting at 125-130°C for 6-8 hours, the mixture is cooled to room temperature to obtain the modified epoxy resin. The optical fiber coating adhesion promoter of this invention can improve the adhesion between the optical fiber and the coating, thereby enhancing the reliability of the optical fiber.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to an adhesion promoter for optical fiber coatings, its preparation method, and its application. Background Technology

[0002] Fiber optic coating is a material specifically designed to coat the surface of optical fibers. Its main purpose is to protect the fiber from physical damage and environmental factors (such as humidity and temperature changes), and to maintain the fiber's optical performance. Fiber optic coating typically consists of two layers: a primary coating and a secondary coating. The primary coating is applied directly to the bare fiber surface, and its thickness is usually around a few micrometers. Its main functions are: to provide cushioning and resilience, absorbing external impacts and preventing the fiber from bending or breaking; to reduce microbending loss, maintaining high efficiency in signal transmission; and to prevent moisture penetration, avoiding performance degradation over time. The secondary coating is a harder coating applied on top of the primary coating, and its thickness can reach tens of micrometers. Its main functions are: to provide additional mechanical protection, enhancing the fiber's abrasion and scratch resistance; to facilitate fiber handling during cabling and installation, such as perforation and bending; and sometimes to serve as a color identifier, facilitating the identification of different fiber types.

[0003] Optical fiber coatings formulated with acrylate resins are used for primary coating. They primarily adhere to the fiber surface through physical forces such as hydrogen bonds. However, the forces formed by hydrogen bonds are relatively weak, and coating peeling may occur during fiber use, affecting the fiber's lifespan. Therefore, adhesion promoters are usually added to the optical fiber coatings.

[0004] Conventional fiber optic coating adhesion promoters, such as silane coupling agents like KH550 and KH560, suffer from poor compatibility, instability, and easy hydrolysis. They also tend to form localized aggregates, resulting in excessive localized adhesion and making the coating impossible to remove completely. Chinese Patent 202211057564.X provides a fiber optic coating adhesion promoter and its preparation method, which requires only a small amount of the promoter to improve the adhesion between the fiber and the coating, thus enhancing fiber reliability. However, its long-term reliability and successful removal rate remain poor, severely impacting its performance and market competitiveness.

[0005] Therefore, there is an urgent need for an adhesion promoter for optical fiber coatings that has good adhesion-promoting effect and high reliability. Summary of the Invention

[0006] The purpose of this invention is to provide an adhesion promoter for optical fiber coatings, its preparation method, and its application, which can improve the adhesion between optical fibers and coatings and enhance the reliability of optical fibers.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An adhesion promoter for optical fiber coatings comprises the following components in parts by weight: 20-25 parts modified epoxy resin, 4-7 parts epoxy acrylate, 12-16 parts modified filler, 32-38 parts propylene glycol methyl ether acetate, 13-18 parts isobutanol, 6-10 parts phosphoric acid, and 5-7 parts water.

[0009] The preparation method of modified epoxy resin is as follows:

[0010] (1) In a nitrogen atmosphere, 700-710 parts by weight of epoxy resin are heated to 135-140℃, and then 0.7-0.9 parts by weight of N,N-dimethylbenzylamine are added. After holding at the temperature for 8-10 hours, a polyepoxy compound is obtained.

[0011] (2) Add 35-38 parts by weight of N-methylethanolamine and 220-230 parts by weight of amino-terminated liquid nitrile rubber to the polyepoxy compound in sequence. After reacting at 125-130℃ for 6-8 hours, cool to room temperature to obtain modified epoxy resin.

[0012] Furthermore, the epoxy resin is selected from one or more of epoxy resin A, epoxy resin B, and epoxy resin C, wherein the epoxy equivalent of epoxy resin A is 179-189 g / Eq; the epoxy equivalent of epoxy resin B is 167-175 g / Eq; and the epoxy equivalent of epoxy resin C is 400-455 g / Eq.

[0013] Furthermore, the epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:(0.5-0.7):(1.3-1.5), and the epoxy equivalent of epoxy resin A is 179-189 g / Eq (brand: Huntsman, model). GY764); the epoxy equivalent of epoxy resin B is 167-175 g / Eq (brand: Huntsman, model). GY289), epoxy resin C has an epoxy equivalent of 400-455 g / Eq (Brand: Huntsman, Model: GY289). GY298).

[0014] Adding both epoxy resin and epoxy acrylate to fiber optic coating adhesion promoters can improve the tensile strength of fiber optic coatings prepared with acrylate resin formulations. However, the effect of these adhesion promoters on improving the long-term reliability of the coatings is not ideal. This invention addresses this issue by combining waterborne epoxy resin EP137 and Huntsman... An epoxy resin modified with a compound of PZ756-1 / 67 epoxy resin and Hansen Epikote 834 liquid bisphenol A type epoxy resin was used to prepare an adhesion promoter for optical fiber coatings, which can improve the long-term reliability of the coatings. By introducing N-methylethanolamine and amino-terminated liquid nitrile rubber into the modified epoxy resin, a more stable cross-linked network can be formed, making it less prone to degradation and enhancing the resin's thermal stability, thereby maintaining the integrity and optical performance of the optical fiber coating. However, under these conditions, the peeling success rate of the optical fiber coating adhesion promoter added to the coating is not ideal.

[0015] Furthermore, the preparation method of the modified filler is as follows:

[0016] (1) Mix carboxylated double-walled carbon nanotubes, carboxylated graphene oxide and carboxylated silica in a mass ratio of 1:(1.2-1.5):(0.4-0.7) to obtain a filler. Under a nitrogen atmosphere, mix 1 part by mass of 3-isocyanate-propyltrimethoxysilane and 0.12-0.15 parts by mass of the filler, sonicate for 20-25 min, add 50-55 parts by mass of N,N-dimethylformamide, stir at 100-108℃ for 2-3 h, centrifuge, and freeze-dry the obtained solid product A to obtain isocyanate-modified filler;

[0017] (2) Mix 9-12 parts by weight of isocyanate-based modified filler and 60-65 parts by weight of ethanol, then add carboxylated polystyrene microsphere aqueous solution dropwise, stir at 55-60℃ for 2-3 hours, centrifuge, and freeze-dry the obtained solid product B to obtain the modified filler.

[0018] Furthermore, the carboxylated polystyrene microspheres in the aqueous solution have an average particle size of 20 nm and a solid content of 2.5 wt%. They were purchased from Xianfeng Nano, catalog number: 103392. Further, the mass ratio of the isocyanate-modified filler to the carboxylated polystyrene microspheres is 10:2-5.

[0019] Furthermore, the carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt%. They were purchased from Xianfeng Nanomaterials, catalog number 100227.

[0020] Furthermore, the carboxylated graphene oxide sheets have a diameter of 0.5-5 micrometers and a thickness of 0.8-1.2 nm. Purchased from Xianfeng Nano, item number: 100009.

[0021] Furthermore, the carboxylated silica has an average size of 20 nm. Purchased from Xianfeng Nano, catalog number: 103113.

[0022] This invention improves the peeling success rate of optical fiber coatings by adding modified fillers to the fiber optic coating adhesion promoter. The fillers, through surface modification, achieve better dispersion in the epoxy resin matrix, preventing aggregation and agglomeration in the coating, thus forming a more uniform coating and reducing defects on the optical fiber surface. Modification with carboxylated polystyrene microspheres improves the compatibility of the system components and enhances the stability of the optical fiber coating adhesion promoter.

[0023] Furthermore, the epoxy acrylate is selected from one or more of CN104NS, CN120NS, CN150NS, and CN2003NS. Purchased from the brand: Sartomer.

[0024] To improve the elongation at break, the epoxy acrylate is further a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:(1.4-1.6):(0.2-0.5).

[0025] This invention also provides a method for preparing an adhesion promoter for optical fiber coatings. The preparation method includes the following steps: mixing propylene glycol methyl ether acetate, isobutanol and water, and under stirring conditions, sequentially adding epoxy resin, modified filler and epoxy acrylate, stirring evenly, and then adding phosphoric acid dropwise, and continuing to stir for 2-3 hours to obtain the product.

[0026] This invention also provides the application of an adhesion promoter for optical fiber coatings, used in the preparation of optical fiber coatings formulated with acrylate resins.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0028] 1. The fiber optic coating adhesion promoter of the present invention simultaneously incorporates modified epoxy resin and epoxy acrylate, which can improve the tensile strength of fiber optic coatings prepared by acrylate resin formulation systems.

[0029] 2. This invention utilizes waterborne epoxy resin EP137 and Huntsman... An epoxy resin modified with PZ756-1 / 67 epoxy resin and Hansen Epikote 834 liquid bisphenol A type epoxy resin was used to prepare an adhesion promoter for optical fiber coatings, which can improve the long-term reliability of the coatings.

[0030] 3. This invention improves the peeling success rate of optical fiber coatings by adding modified fillers to the optical fiber coating adhesion promoter. Modification with carboxylated polystyrene microspheres enhances the compatibility of the system components and improves the stability of the optical fiber coating adhesion promoter. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides an adhesion promoter for optical fiber coatings, comprising the following components in parts by weight: 22 parts modified epoxy resin, 6 parts epoxy acrylate, 14 parts modified filler, 36 parts propylene glycol methyl ether acetate, 15 parts isobutanol, 8 parts phosphoric acid, and 6 parts water.

[0034] The preparation method of modified epoxy resin is as follows:

[0035] (1) In a nitrogen atmosphere, 705 parts by weight of epoxy resin were heated to 138°C, and then 0.8 parts by weight of N,N-dimethylbenzylamine were added. After holding at the temperature for 9 hours, a polyepoxy compound was obtained.

[0036] (2) 37 parts by mass of N-methylethanolamine and 225 parts by mass of amino-terminated liquid nitrile rubber were added to the polyepoxy compound in sequence. After reacting at 127°C for 7 hours, the mixture was cooled to room temperature to obtain the modified epoxy resin.

[0037] Amino-terminated liquid nitrile rubber, purchased from Jining Fangyu Chemical Co., Ltd., with an average molecular weight of 10,000 Da.

[0038] The epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:0.6:1.4. The epoxy equivalent of epoxy resin A is 179-189 g / Eq (product brand: Huntsman, model). GY764); the epoxy equivalent of epoxy resin B is 167-175 g / Eq (product brand: Huntsman, model...). GY289), epoxy resin C has an epoxy equivalent of 400-455 g / Eq (product brand: Huntsman, model...). GY298).

[0039] The preparation method of the modified filler is as follows:

[0040] (1) Carboxylated double-walled carbon nanotubes, carboxylated graphene oxide and carboxylated silica were mixed in a mass ratio of 1:1.4:0.6 to obtain a filler. Under a nitrogen atmosphere, 1 part by mass of 3-isocyanate-propyltrimethoxysilane and 0.14 parts by mass of the filler were mixed and sonicated for 22 min. 52 parts by mass of N,N-dimethylformamide were added and stirred at 105 °C for 2.5 h. After centrifugation, the solid product A was obtained and freeze-dried to obtain the isocyanate-modified filler.

[0041] (2) Mix 10 parts by mass of isocyanate-based modified filler and 62 parts by mass of ethanol, then add carboxylated polystyrene microsphere aqueous solution dropwise, stir at 57°C for 2.5 h, centrifuge, and freeze-dry the resulting solid product B to obtain the modified filler.

[0042] The carboxylated polystyrene microspheres in the aqueous solution had an average particle size of 20 nm and a solid content of 2.5 wt%. They were purchased from Xianfeng Nano, catalog number: 103392.

[0043] The mass ratio of the isocyanate-modified filler to the carboxylated polystyrene microspheres is 10:3.

[0044] The carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt%. They were purchased from Xianfeng Nanomaterials, catalog number 100227.

[0045] Carboxylated graphene oxide sheets with a diameter of 0.5-5 micrometers and a thickness of 0.8-1.2 nm. Purchased from Xianfeng Nanomaterials, item number: 100009.

[0046] The carboxylated silica has an average size of 20 nm. It was purchased from Xianfeng Nano, item number: 103113.

[0047] The epoxy acrylate is a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:1.5:0.4.

[0048] The preparation method of the optical fiber coating adhesion promoter includes the following steps: propylene glycol methyl ether acetate, isobutanol and water are mixed, and under stirring conditions, epoxy resin, modified filler and epoxy acrylate are added in sequence. After stirring evenly, phosphoric acid is added dropwise, and stirring is continued for 2.5 hours to obtain the product.

[0049] Example 2

[0050] This embodiment provides an adhesion promoter for optical fiber coatings, comprising the following components in parts by weight: 20 parts modified epoxy resin, 4 parts epoxy acrylate, 12 parts modified filler, 32 parts propylene glycol methyl ether acetate, 13 parts isobutanol, 6 parts phosphoric acid, and 5 parts water.

[0051] The preparation method of modified epoxy resin is as follows:

[0052] (1) In a nitrogen atmosphere, 700 parts by weight of epoxy resin were heated to 135°C, and then 0.7 parts by weight of N,N-dimethylbenzylamine were added. After holding at the temperature for 8 hours, a polyepoxy compound was obtained.

[0053] (2) 35 parts by mass of N-methylethanolamine and 220 parts by mass of amino-terminated liquid nitrile rubber were added to the polyepoxy compound in sequence. After reacting at 125°C for 6 hours, the mixture was cooled to room temperature to obtain the modified epoxy resin.

[0054] Amino-terminated liquid nitrile rubber, purchased from Jining Fangyu Chemical Co., Ltd., with an average molecular weight of 10,000 Da.

[0055] The epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:0.5:1.3. The epoxy equivalent of epoxy resin A is 179-189 g / Eq (product brand: Huntsman, model). GY764); the epoxy equivalent of epoxy resin B is 167-175 g / Eq (product brand: Huntsman, model...). GY289), epoxy resin C has an epoxy equivalent of 400-455 g / Eq (product brand: Huntsman, model...). GY298).

[0056] The preparation method of the modified filler is as follows:

[0057] (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanate-propyltrimethoxysilane and 0.12 parts by mass of filler were mixed and sonicated for 20 min. 50 parts by mass of N,N-dimethylformamide were added and stirred at 100 °C for 2 h. After centrifugation, the solid product A was obtained and freeze-dried to obtain isocyanate-modified filler.

[0058] (2) Mix 10 parts by mass of isocyanate-based modified filler and 60 parts by mass of ethanol, then add carboxylated polystyrene microsphere aqueous solution dropwise, stir at 55°C for 2 hours, centrifuge, and freeze-dry the resulting solid product B to obtain the modified filler.

[0059] The carboxylated polystyrene microspheres in the aqueous solution had an average particle size of 20 nm and a solid content of 2.5 wt%. They were purchased from Xianfeng Nano, catalog number: 103392.

[0060] The mass ratio of the isocyanate-modified filler to the carboxylated polystyrene microspheres is 5:1.

[0061] The carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt%. They were purchased from Xianfeng Nanomaterials, catalog number 100227.

[0062] The epoxy acrylate is a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:1.4:0.2.

[0063] The preparation method of the optical fiber coating adhesion promoter includes the following steps: propylene glycol methyl ether acetate, isobutanol and water are mixed, and under stirring conditions, epoxy resin, modified filler and epoxy acrylate are added in sequence. After stirring evenly, phosphoric acid is added dropwise, and stirring is continued for 2 hours to obtain the product.

[0064] Example 3

[0065] This embodiment provides an adhesion promoter for optical fiber coatings, comprising the following components in parts by weight: 25 parts modified epoxy resin, 7 parts epoxy acrylate, 16 parts modified filler, 38 parts propylene glycol methyl ether acetate, 18 parts isobutanol, 10 parts phosphoric acid, and 7 parts water.

[0066] The preparation method of modified epoxy resin is as follows:

[0067] (1) In a nitrogen atmosphere, 710 parts by weight of epoxy resin were heated to 140°C, and then 0.9 parts by weight of N,N-dimethylbenzylamine were added. After holding at the temperature for 10 hours, a polyepoxy compound was obtained.

[0068] (2) 38 parts by mass of N-methylethanolamine and 230 parts by mass of amino-terminated liquid nitrile rubber were added to the polyepoxy compound in sequence. After reacting at 130°C for 8 hours, the mixture was cooled to room temperature to obtain the modified epoxy resin.

[0069] Amino-terminated liquid nitrile rubber, purchased from Jining Fangyu Chemical Co., Ltd., with an average molecular weight of 10,000 Da.

[0070] The epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:0.7:1.5. The epoxy equivalent of epoxy resin A is 179-189 g / Eq (product brand: Huntsman, model). GY764); the epoxy equivalent of epoxy resin B is 167-175 g / Eq (product brand: Huntsman, model...). GY289), epoxy resin C has an epoxy equivalent of 400-455 g / Eq (product brand: Huntsman, model...). GY298).

[0071] The preparation method of the modified filler is as follows:

[0072] (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanate-propyltrimethoxysilane and 0.15 parts by mass of filler were mixed and sonicated for 25 min. 55 parts by mass of N,N-dimethylformamide were added and stirred at 108 °C for 3 h. After centrifugation, the solid product A was obtained and freeze-dried to obtain isocyanate-modified filler.

[0073] (2) Mix 10 parts by mass of isocyanate-based modified filler and 65 parts by mass of ethanol, then add carboxylated polystyrene microsphere aqueous solution dropwise, stir at 60°C for 3 hours, centrifuge, and freeze-dry the resulting solid product B to obtain the modified filler.

[0074] The carboxylated polystyrene microspheres in the aqueous solution had an average particle size of 20 nm and a solid content of 2.5 wt%. They were purchased from Xianfeng Nano, catalog number: 103392.

[0075] The mass ratio of the isocyanate-modified filler to the carboxylated polystyrene microspheres is 2:1.

[0076] The carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt%. They were purchased from Xianfeng Nanomaterials, catalog number 100227.

[0077] Carboxylated graphene oxide sheets with a diameter of 0.5-5 micrometers and a thickness of 0.8-1.2 nm. Purchased from Xianfeng Nanomaterials, item number: 100009.

[0078] The carboxylated silica has an average size of 20 nm. It was purchased from Xianfeng Nano, item number: 103113.

[0079] The epoxy acrylate is a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:1.6:0.5.

[0080] The preparation method of the optical fiber coating adhesion promoter includes the following steps: propylene glycol methyl ether acetate, isobutanol and water are mixed, and under stirring conditions, epoxy resin, modified filler and epoxy acrylate are added in sequence. After stirring evenly, phosphoric acid is added dropwise, and stirring is continued for 3 hours to obtain the product.

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 1 is that this example provides an adhesion promoter for optical fiber coating, comprising the following components in parts by weight: 15 parts modified epoxy resin, 13 parts epoxy acrylate, 14 parts modified filler, 36 parts propylene glycol methyl ether acetate, 15 parts isobutanol, 8 parts phosphoric acid, and 6 parts water.

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 1 is that the epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:1:1, and the epoxy equivalent of epoxy resin A is 179-189 g / Eq (product brand: Huntsman, model). GY764); the epoxy equivalent of epoxy resin B is 167-175 g / Eq (product brand: Huntsman, model...). GY289), epoxy resin C has an epoxy equivalent of 400-455 g / Eq (product brand: Huntsman, model...). GY298).

[0085] Comparative Example 3

[0086] The difference between this comparative example and Example 1 is as follows: the epoxy resin is a compound of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:0.6:1.4. The epoxy equivalent of epoxy resin A is 460-630 g / mol (waterborne epoxy resin EP137, purchased from Guangdong Qirun New Materials Co., Ltd.); the epoxy equivalent of epoxy resin B is 210-230 g / mol (Phoenix brand WSR6101 epoxy resin); and the epoxy equivalent of epoxy resin C is 184-195 g / mol (Phoenix epoxy resin WSR618).

[0087] The epoxy resin is a mixture of American Hansoh Epikote WD-52A, American Hansoh Epikote™ 6520-WH-53A and Phoenix Epoxy Resin E44 in a mass ratio of 1:0.6:1.4.

[0088] Comparative Example 4

[0089] The difference between this comparative example and Example 1 is that the aqueous solution of carboxylated polystyrene microspheres is replaced with an aqueous solution of nano-titanium dioxide, the nano-titanium dioxide content in the aqueous solution of nano-titanium dioxide is 2.5 wt%, and the average particle size of nano-titanium dioxide is 20 nm.

[0090] Comparative Example 5

[0091] The difference between this comparative example and Example 1 is as follows: the carboxylated double-walled carbon nanotubes have a diameter of 10-20 nm, a length of 0.5-2 μm, and a carboxyl content of 2 wt%. They were purchased from Xianfeng Nanomaterials, catalog number 100262. The average size of the carboxylated silica is 100 nm. It was purchased from Xianfeng Nanomaterials, catalog number 103114. The carboxylated graphene oxide was replaced with graphene oxide, with a sheet diameter of 0.5–5 μm and a thickness of 0.8–1.2 nm, purchased from Xianfeng Nanomaterials, catalog number 100602.

[0092] Comparative Example 6

[0093] The difference between this comparative example and Example 1 is that carboxylated double-walled carbon nanotubes, carboxylated graphene oxide, and carboxylated silicon dioxide were mixed in a mass ratio of 1:1:1 to obtain the filler.

[0094] Comparative Example 7

[0095] The difference between this comparative example and Example 1 is that the epoxy acrylate is a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:1:1.

[0096] Performance test

[0097] 1. Add the fiber optic coating adhesion promoters prepared in Examples 1-3 and Comparative Examples 1-7 to the acrylate coating for fiber optics, with an addition amount of 5 wt%. Conduct the following performance tests:

[0098] The tensile strength and elongation at break tests are respectively carried out in accordance with GBT1040.2-2006 and GBT1040.3-2006.

[0099] 2. Coat the above coating as a primary coating on the surface of the optical fiber with a thickness of 5 microns, and conduct the following performance tests:

[0100] Long-term reliability: Immerse a 150m optical fiber with a diameter of 125μm completely in hot water at 85°C, and measure its cladding loss every 24h (the cladding loss less than 15 dB / km is qualified), and determine the number of qualified days.

[0101] Stripping performance: Take a 1m long optical fiber with a diameter of 400μm, strip it with a fiber stripper, strip 60 roots in each group, wipe the stripped part three times with acetone after each group of samples are stripped, and observe under a microscope whether there is coating residue at the stripped part. It is qualified if the stripped part is clean without residue.

[0102] 3. Storage stability: Place the fiber optic coating adhesion promoters prepared in Examples 1-3 and Comparative Examples 1-7 in a 100mL beaker and expose them at room temperature. Once any one of the phenomena such as crystallization, whitening, turbidity, and delamination occurs, it is unqualified. Count the number of qualified days.

[0103] Table 1 Performance test results

[0104]

[0105]

[0106] From the above performance test results, it can be seen that the fiber optic coating adhesion promoters of Examples 1-3 can improve the adhesion between the optical fiber and the coating and enhance the reliability of the optical fiber. In particular, the comprehensive performance of Example 1 is the most prominent, which is mainly because various components play a synergistic role.

[0107] The comparative examples, however, did not employ the necessary technical solutions, resulting in significantly inferior performance compared to the examples. The comparative examples altered the ratio of modified epoxy resin and epoxy acrylate, leading to a decrease in overall effectiveness. This demonstrates that the modified epoxy resin and epoxy acrylate scheme significantly impacts the overall effect of the fiber optic coating adhesion promoter. Comparative examples 2-3 did not use the modified epoxy resin scheme, which affected reliability. These experimental results further demonstrate the importance of the technical solutions defined in this invention for its technical effectiveness.

[0108] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An adhesion promoter for optical fiber coatings, characterized in that, The composition includes the following components in parts by weight: 20-25 parts modified epoxy resin, 4-7 parts epoxy acrylate, 12-16 parts modified filler, 32-38 parts propylene glycol methyl ether acetate, 13-18 parts isobutanol, 6-10 parts phosphoric acid, and 5-7 parts water. The preparation method of modified epoxy resin is as follows: (1) In a nitrogen atmosphere, 700-710 parts by weight of epoxy resin are heated to 135-140℃, and then 0.7-0.9 parts by weight of N,N-dimethylbenzylamine are added. After holding at the temperature for 8-10 hours, a polyepoxy compound is obtained. (2) Add 35-38 parts by weight of N-methylethanolamine and 220-230 parts by weight of amino-terminated liquid nitrile rubber to the polyepoxy compound in sequence. After reacting at 125-130℃ for 6-8 hours, cool to room temperature to obtain modified epoxy resin. The epoxy resin is a blend of epoxy resin A, epoxy resin B, and epoxy resin C in a mass ratio of 1:(0.5-0.7):(1.3-1.5). The epoxy equivalent of epoxy resin A is 179-189 g / Eq; the epoxy equivalent of epoxy resin B is 167-175 g / Eq; and the epoxy equivalent of epoxy resin C is 400-455 g / Eq. The preparation method of the modified filler is as follows: (1) Mix carboxylated double-walled carbon nanotubes, carboxylated graphene oxide and carboxylated silica in a mass ratio of 1:(1.2-1.5):(0.4-0.7) to obtain a filler. Under a nitrogen atmosphere, mix 1 part by mass of 3-isocyanate-propyltrimethoxysilane and 0.12-0.15 parts by mass of the filler, sonicate for 20-25 min, add 50-55 parts by mass of N,N-dimethylformamide, stir at 100-108℃ for 2-3 h, centrifuge, and freeze-dry the obtained solid product A to obtain isocyanate-modified filler. (2) Mix 9-12 parts by weight of isocyanate-based modified filler and 60-65 parts by weight of ethanol, then add carboxylated polystyrene microsphere aqueous solution dropwise, stir at 55-60℃ for 2-3 hours, centrifuge, and freeze-dry the solid product B obtained to obtain the modified filler. The epoxy acrylate is a mixture of CN104NS, CN150NS and CN2003NS in a mass ratio of 1:(1.4-1.6):(0.2-0.5).

2. The optical fiber coating adhesion promoter according to claim 1, characterized in that, The average particle size of the carboxylated polystyrene microspheres in the aqueous solution was 20 nm, and the solid content was 2.5 wt%.

3. The optical fiber coating adhesion promoter according to claim 2, characterized in that, The mass ratio of the isocyanate-modified filler to the carboxylated polystyrene microspheres is 10:2-5.

4. A method for preparing the optical fiber coating adhesion promoter according to any one of claims 1-3, characterized in that, The preparation method includes the following steps: propylene glycol methyl ether acetate, isobutanol and water are mixed, and under stirring conditions, epoxy resin, modified filler and epoxy acrylate are added in sequence. After stirring evenly, phosphoric acid is added dropwise, and stirring is continued for 2-3 hours to obtain the final product.

5. The application of the optical fiber coating adhesion promoter according to any one of claims 1-3, characterized in that, Fiber optic coatings prepared using acrylate resin formulation systems.

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