Low-viscosity and high-strength optical fiber coloring ink based on novel photoinitiator system as well as preparation method, use method and application of low-viscosity and high-strength optical fiber coloring ink

Abstract

The invention discloses low-viscosity and high-strength optical fiber coloring ink based on a novel photoinitiator system as well as a preparation method, a use method and application of the low-viscosity and high-strength optical fiber coloring ink. The optical fiber coloring ink is prepared from the following components in parts by weight: 30 parts of polyurethane acrylate, 20 to 30 parts of epoxy acrylate, 10 parts of reactive diluent, 2 to 10 parts of coloring pigment, 1.5 to 3 parts of bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide (BAPO), 0.5 to 1.0 part of isopropyl thioxanthone (ITX) and 0.3 to 0.8 part of 2, 4, 6-tri (dimethylaminomethyl) phenol (DMP-30). The optical fiber coloring ink provided by the invention has extremely low hydrogen evolution amount (24h, 100 DEG C) of 0.37 [mu] L / g. The optical fiber coloring ink has low viscosity (2020 mPa.s, 25 DEG C) and high tensile shear strength (13.7 MPa), and compared with existing optical fiber coloring ink, the viscosity is reduced by 50%, the tensile shear strength is improved by 20%, and the curing degree is improved by 8%.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, its preparation method, usage method, and application. Background Technology

[0002] Fiber optic coloring ink is a special ink used to coat the surface of optical fibers with different colors. Its main function is to give the fibers identification marks, making it easier to distinguish and manage individual optical fibers in complex optical cable structures. Currently, fiber optic coloring inks on the market are mainly divided into two categories: solvent-based and non-solvent-based. Among them, UV curing technology has become the mainstream development direction in the industry due to its environmental friendliness and high efficiency. Summary of the Invention

[0003] To reduce the viscosity and increase the strength of optical fiber coloring ink, enabling its rapid curing and coloring for marking and physical protection on optical fiber surfaces, this invention proposes a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, comprising the following components: 30 parts by weight of polyurethane acrylate, 20-30 parts by weight of epoxy acrylate, 10 parts by weight of reactive diluent, 2-10 parts by weight of coloring pigment, 1.5-3 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BAPO), 0.1-1.0 parts by weight of isopropylthioxanthone (ITX), and 0.3-0.8 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30).

[0004] Optionally, the content of the epoxy acrylate is 20 parts by weight.

[0005] Optionally, the reactive diluent is one or a combination of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate; preferably, the reactive diluent is a combination of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate in a mass ratio of 1:1.

[0006] Optionally, the coloring pigment is one or a combination of phthalocyanine blue BGS, phthalocyanine green G, lithol magenta, and carbon black; preferably phthalocyanine blue BGS or carbon black, more preferably carbon black.

[0007] Optionally, the content of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is 2-3 parts by weight, preferably 2.0 parts by weight.

[0008] Optionally, the content of isopropylthioxanthone (ITX) is 0.5 parts by weight.

[0009] Optionally, the content of 2,4,6-tris(dimethylaminomethyl)phenol is 0.5 parts by weight.

[0010] Optionally, it may also include dispersants, leveling agents, defoamers, hindered phenolic antioxidants, and adhesion promoters.

[0011] Optionally, the dispersant is a polyurethane dispersant; the polyurethane dispersant is one or a combination of BYK-190, BYK-2190, EFKA4010, NEO-1101, and DH-6328; preferably DH-6328 or BYK-2190; more preferably DH-6328.

[0012] Optionally, the leveling agent is a polyether-modified siloxane, used in an amount of 0.1-0.3 parts by weight, preferably 0.2 parts by weight.

[0013] Optionally, the hindered phenolic antioxidant is 2,6-di-tert-butyl-p-cresol (BHT), with a content of 0.2-1.0 parts by weight, preferably 0.5 parts by weight.

[0014] Optionally, the adhesion promoter is 2-hydroxyethyl methacrylate phosphate (HEMAP), with a content of 0.2-1.0 parts by weight, preferably 0.5 parts by weight.

[0015] Optionally, the defoamer is a mineral oil-based non-silicone defoamer, preferably RP-6213, with a content of 0.01-0.1 parts by weight, preferably 0.05 parts by weight.

[0016] Optionally, the reactive diluent is a combination of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate in a mass ratio of 1:1.

[0017] This invention also provides a method for preparing a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, comprising the following steps: Step 1: Dry the coloring pigment to remove moisture, and obtain the dried coloring pigment; Step 2: Add the dried coloring pigment and dispersant to a high-speed disperser at a mass ratio of 2:3, mix evenly to obtain the coloring agent; Step 3: Add 10% of the total mass of preheated reactive diluent to the colorant, and continue to disperse it in a high-speed disperser to form a preliminary uniform pigment predispersed slurry. Step 4: Transfer the pre-dispersed pigment slurry into a three-roll mill, control the roller temperature at 20-30℃, adjust the roller spacing, and circulate the slurry until the particle size is <1μm to obtain a stable pigment slurry. Step 5: Under low-speed stirring, add the preheated polyurethane acrylate and epoxy acrylate to the reactor in sequence and stir for 10 minutes; then slowly add the color paste and the remaining preheated reactive diluent and continue stirring to form a uniform main resin matrix. Step 6: While maintaining stirring and avoiding light, add BAPO, ITX and DMP-30 of the initiator system to the main resin matrix, and continue to add the hindered phenolic antioxidant, adhesion promoter, leveling agent and defoamer in sequence to ensure that all components are completely mixed and there are no bubbles. Step 7: Filter, store in the dark, and obtain the final low-viscosity, high-strength optical fiber coloring ink based on the novel photoinitiator system.

[0018] The present invention also provides a method for using a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, wherein the ink is cured by irradiating it with a UV-LED lamp for 10 seconds.

[0019] Optionally, the UV-LED lamp is a 365nm / 395nm / 405nm multi-band composite lamp.

[0020] This invention also provides an application of a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, used for rapid curing, coloring, marking, and physical protection of optical fiber surfaces.

[0021] The advantages and beneficial effects of this invention are as follows: (1) The optical fiber coloring ink of the present invention has an extremely low hydrogen evolution amount (24h, 100℃) of 0.37μL / g.

[0022] (2) The optical fiber coloring ink of the present invention has a lower viscosity (2020 mPa·s, 25°C) and a higher tensile shear strength (13.7 MPa). Compared with existing optical fiber coloring inks, the viscosity is reduced by 50%, the tensile shear strength is increased by 20%, and the curing degree is increased by 8%.

[0023] (3) The optical fiber coloring ink of the present invention is used to color optical fibers. After curing, it can be wiped 50 times without falling off, and has good abrasion resistance.

[0024] (4) The optical fiber coloring ink of the present invention has a high degree of curing and a double bond conversion rate of 92.33%. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the embodiments.

[0026] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0027] The present invention provides a method for preparing a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, the specific steps of which are as follows: Step 1: Place the coloring pigment in a vacuum oven at 80℃ for 2 hours to remove moisture and avoid generating air bubbles during the mixing process, thus obtaining the dried coloring pigment. Step 2: The reactive diluent composed of polyurethane acrylate, epoxy acrylate, tripropylene glycol diacrylate and 1,6-hexanediol diacrylate is preheated at 30°C to obtain preheated polyurethane acrylate, epoxy acrylate and reactive diluent, which reduces viscosity and facilitates mixing. Step 3: Add the dried carbon black and polyurethane dispersant DH-6328 to a high-speed disperser at a mass ratio of 2:3, mix evenly to obtain a carbon black slurry; add 10% of the total mass of preheated reactive diluent to the carbon black slurry, disperse at 1500 rpm for 20 minutes to form a preliminary uniform pigment predispersed slurry. Step 4: Transfer the pre-dispersed pigment slurry into a three-roll mill, control the roller temperature at 25°C, adjust the roller spacing, and circulate the mill 5 times until the slurry particle size is <1μm (confirmed by laser particle size analyzer) to obtain a stable pigment slurry; the roller spacing is 0.2mm for the first pass, 0.1mm for the second pass, and 0.02mm for the third pass. Step 5: Under low-speed stirring at 800 rpm, add the preheated polyurethane acrylate and epoxy acrylate to the reactor in sequence and stir for 10 min; then slowly add the color paste and the remaining preheated reactive diluent and continue stirring for 20 min to form a uniform main resin matrix.

[0028] Step 6: While maintaining a stirring speed of 800 rpm, add BAPO, ITX and DMP-30 of the initiator system to the main resin matrix under light-protected conditions, and stir for 15 minutes to ensure that the initiator system is evenly dispersed and to avoid excessively high local concentrations. Step 7: After premixing the hindered phenolic antioxidant 2,6-di-tert-butyl-p-cresol (BHT) and the adhesion promoter 2-hydroxyethyl methacrylate phosphate (HEMAP), add them to the main resin matrix system and stir for 10 minutes. Step 8: Continue to add leveling agent polyether modified siloxane to the main resin matrix system, stir for 15 minutes to improve interfacial compatibility and spreadability. Step 9: Finally, add mineral oil-based non-silicone defoamer RP-6213 to the main resin matrix system and stir at low speed for 5 minutes to avoid introducing new bubbles through high-speed stirring.

[0029] Step 10: Adjust the stirring speed to 1500 rpm and continue stirring for 30 minutes to ensure that all components are completely combined; during this period, control the system temperature to not exceed 40℃ to avoid premature decomposition of the initiator or abnormal changes in resin viscosity. Step 11: Filter the ink using a 300-mesh nylon filter to remove incompletely dispersed particles or impurities; after filtration, quickly transfer it to a brown sealed container for light protection to obtain the final low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system.

[0030] The compounds used in the examples were sourced from the following sources: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is from Shandong Jiuri Chemical Technology Co., Ltd. (China); Isopropylthioxanthone is sourced from Anhui Shenlan Huahong Color Materials Co., Ltd. (China); The carbon black is from Shanghai Maclean Biotechnology Co., Ltd. (China); 2,4,6-Tris(dimethylaminomethyl)phenol is from Shanghai Maclean Biochemical Technology Co., Ltd. (China). 2,6-Di-tert-butyl-p-cresol is from Shanghai Maclean Biotechnology Co., Ltd. (China). 2-Hydroxyethyl methacrylate phosphate is from Shanghai Maclean Biotechnology Co., Ltd. (China); The mineral oil-based non-silicone defoamer is from Shandong Punio Water Treatment Technology Co., Ltd. (China); The polyurethane dispersant (DH-6328) is from Shanghai McLean Biochemical Technology Co., Ltd. (China). The polyurethane acrylate was synthesized in-house by Beijing University of Chemical Technology (China). The synthesis method is as follows: Under nitrogen protection, diisocyanate and polyol were added to a reaction vessel at a NCO / OH molar ratio of 2:1. The mixture was heated to 75°C and stirred for 2 hours. The characteristic peak of the -NCO group (2270 cm⁻¹) was monitored by infrared spectroscopy. -1 A polyurethane prepolymer with terminal-NCO was prepared. The temperature was maintained at 75°C, and hydroxyl-containing acrylate was added dropwise to the prepolymer. The NCO / OH molar ratio was controlled at 1.1:1. The reaction was carried out for 3 hours until the characteristic peak of -NCO in the infrared spectrum completely disappeared, indicating that the reaction was complete. Finally, the temperature was lowered to below 40°C, and impurities were removed by filtration to obtain a light yellow transparent polyurethane acrylate prepolymer.

[0031] The epoxy acrylate was prepared by Beijing University of Chemical Technology (China). The synthesis method is as follows: E-51 epoxy resin was dehydrated under vacuum at 60℃ for 1 hour to remove impurities. Acrylic monomer (containing MEHQ polymerization inhibitor) was stirred and dissolved. Under nitrogen protection, it was fed at a molar ratio of epoxy groups to carboxyl groups of 1:1.1. 0.5% catalyst was added, the temperature was raised to 80℃, and the reaction was stirred for 4 hours. The acid value was measured every 1 hour. When the acid value dropped to 5 mg KOH / g, the reaction was terminated. The temperature was lowered to below 40℃, and the mixture was filtered to obtain a light yellow transparent prepolymer.

[0032] The testing instruments and conditions used in this embodiment are as follows: Universal tensile testing machine: The model of the testing machine is ESM303, and the test method is in accordance with GB / T 7124-2008; MEK test (butanone method): The test method shall be performed in accordance with GB / T 23989-2009; Rotational rheometer: The testing machine was an Anton Paar MCR 102, and the test method was in accordance with GB / T 12007.7-1989. The viscosity was taken as the average of three measurements. Hydrogen evolution test: gas chromatography, the testing machine model is Shimadzu GC-2014C, and the test method is in accordance with GB / T4946-2008; Titration of double bonds: The test method shall be in accordance with GB / T 11136-2025.

[0033] Curing operation The UV-LED lamp used for curing the ink is a multi-band composite lamp of 365 nm / 395 nm / 405 nm, which completes the curing process in 10 seconds.

[0034] The composition of the optical fiber coloring ink in a specific embodiment is as follows: Example 1 The composition of the optical fiber coloring ink in this embodiment is shown in Table 1.

[0035] Table 1 Example 2 The composition of the ink in this embodiment is shown in Table 2.

[0036] Table 2 Example 3 The composition of the ink in this embodiment is shown in Table 3.

[0037] Table 3 Example 4 The composition of the ink in this embodiment is shown in Table 4.

[0038] Table 4 Example 5 The composition of the ink in this embodiment is shown in Table 5.

[0039] Table 5 The performance test results of the optical fiber coloring inks obtained in Examples 1-5 are shown in Table 6.

[0040] Table 6. Performance of the optical fiber coloring inks prepared in Examples 1-5 Compared to Example 1, Example 2 shows an increased content of epoxy acrylate, which allows the rigid epoxy skeleton provided by the epoxy acrylate to effectively block the penetration of methyl ethyl ketone (MEK) molecules. With the increased epoxy content, the proportion of flexible polyester segments in the ink decreases, the crosslinking network density increases, and MEK is less likely to penetrate and swell the resin network, resulting in an increase in the abrasion resistance of the cured ink coating to 62 cycles. Due to the significant increase in epoxy group content, its tensile shear strength also increases to 17.2 MPa. After the epoxy groups open, hydroxyl groups (-OH) are easily retained, and trace amounts of amine catalysts may remain during the synthesis process. These groups easily react with trace metal impurities in the substrate or system to generate hydrogen gas. The significant increase in the number of epoxy groups in Example 1 led to an increase in hydrogen evolution to 1.78 μL / g.

[0041] Compared to Example 1, Example 3 shows a decrease in the content of epoxy acrylate, which means the rigid epoxy skeleton provided by the epoxy acrylate cannot effectively block the penetration of methyl ethyl ketone (MEK) molecules. This decrease increases the proportion of flexible polyester segments in the ink, leading to stronger segment mobility, a lower crosslinking network density, and easier penetration and swelling of the resin network by MEK. This results in surface erosion and peeling of the paint film, ultimately reducing the abrasion resistance of the cured ink coating to 15 cycles, rendering it unusable for practical applications. Due to the significant decrease in epoxy group content, its tensile shear strength also drops sharply to 8.3 MPa. After the epoxy groups open, hydroxyl groups (-OH) are easily retained, and trace amounts of amine catalysts may remain during the synthesis process. These groups readily react with trace metal impurities in the substrate or system to generate hydrogen gas. The significant decrease in the number of epoxy groups in Example 2 resulted in a reduction in hydrogen evolution to 0.21 μL / g.

[0042] Compared with Example 1, Example 4 showed a decrease in the content of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, resulting in insufficient free radical generation and an inability to meet curing requirements. All properties exhibited a linear decline, which could not be fully compensated for by the co-initiators (ITX and DMP-30). The insufficient free radical concentration, coupled with the absorption of some UV light by the carbon black, meant that deep free radicals were almost unable to initiate double bond reactions, leading to an incomplete crosslinking network. Ultimately, this resulted in a significant decrease in the number of abrasion cycles and a drop in tensile shear strength to 7.7 MPa.

[0043] Compared to Example 1, Example 5 showed an increase in the content of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, leading to a higher concentration of free radicals and a greater probability of double bond collisions with the resin and diluent. This effectively compensated for the insufficient free radical content caused by carbon black light absorption, resulting in a more complete deep double bond reaction. However, excessive free radicals could lead to over-crosslinking, increased internal stress in the paint film, decreased flexibility, and a reduction in the number of methyl ethyl ketone (MEK) rubbing cycles. In production, the initiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is expensive, and increasing its content did not bring about more ideal economic benefits.

Claims

1. A low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system, characterized in that, It contains the following components: 30 parts by weight of polyurethane acrylate, 20-30 parts by weight of epoxy acrylate, 10 parts by weight of reactive diluent, 2-10 parts by weight of coloring pigment, 1.5-3 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (BAPO), 0.5-1.0 parts by weight of isopropylthioxanthone (ITX), and 0.3-0.8 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30).

2. The low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system according to claim 1, characterized in that, It also contains dispersants, leveling agents, defoamers, hindered phenolic antioxidants, and adhesion promoters.

3. The low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system according to claim 1, characterized in that, The reactive diluent is one or a combination of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate.

4. The low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system according to claim 1, characterized in that, The coloring pigment is one or a combination of phthalocyanine blue BGS, phthalocyanine green G, lithol magenta, and carbon black.

5. The low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system according to claim 2, characterized in that, The dispersant is a polyurethane dispersant; and / or, the leveling agent is a polyether-modified siloxane; and / or, the hindered phenolic antioxidant is 2,6-di-tert-butyl-p-cresol (BHT); and / or, the adhesion promoter is 2-hydroxyethyl methacrylate phosphate (HEMAP); and / or, the defoamer is a mineral oil-based non-silicone defoamer.

6. A method for preparing a low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Dry the coloring pigment to remove moisture, and obtain the dried coloring pigment; Step 2: Add the dried coloring pigment and dispersant to a high-speed disperser at a mass ratio of 2:3, mix evenly to obtain the coloring agent; Step 3: Add 10% of the total mass of preheated reactive diluent to the colorant, and continue to disperse it in a high-speed disperser to form a preliminary uniform pigment predispersed slurry. Step 4: Transfer the pre-dispersed pigment slurry into a three-roll mill, control the roller temperature at 20-30℃, adjust the roller spacing, and circulate the slurry until the particle size is <1μm to obtain a stable pigment slurry. Step 5: Under low-speed stirring, add the preheated polyurethane acrylate and epoxy acrylate to the reactor in sequence and stir for 10 minutes; then slowly add the color paste and the remaining preheated reactive diluent and continue stirring to form a uniform main resin matrix. Step 6: While maintaining stirring and avoiding light, add BAPO, ITX and DMP-30 of the initiator system to the main resin matrix, and continue to add the hindered phenolic antioxidant, adhesion promoter, leveling agent and defoamer in sequence to ensure that all components are completely mixed and there are no bubbles. Step 7: Filter, store in the dark, and obtain the final low-viscosity, high-strength optical fiber coloring ink based on the novel photoinitiator system.

7. The preparation method according to claim 6, characterized in that, The preparation process of the dried coloring pigment is as follows: place the coloring pigment in a vacuum oven at 80°C and dry for 2 hours to remove moisture.

8. The method of using the low-viscosity, high-strength optical fiber coloring ink based on a novel photoinitiator system obtained by the preparation method according to claim 6, characterized in that, The ink is cured by irradiating it with a UV-LED lamp for 10 seconds.

9. The method of use according to claim 8, characterized in that, The UV-LED lamp is a multi-band composite lamp with wavelengths of 365nm / 395nm / 405nm.

10. The application of the low-viscosity, high-strength optical fiber coloring ink based on the novel photoinitiator system according to any one of claims 1-5, characterized in that, Used for rapid curing of color markings and physical protection on optical fiber surfaces.

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