Photocuring high-temperature-resistant optical fiber coating and preparation method thereof

Abstract

The invention provides a photocuring high-temperature-resistant optical fiber coating and a preparation method thereof, and the photocuring high-temperature-resistant optical fiber coating comprises the following components by weight: 40-80% of high-modulus acrylate modified methyl phenyl silicone oil; 10-50% of low-modulus acrylic ester modified methyl phenyl silicone oil; 5-30% of an acrylate monomer; 0.5 to 6% of a photoinitiator; and 0.05-1% of an antioxidant. According to the invention, high-modulus and low-modulus acrylic ester modified methyl phenyl silicone oil is compounded, high-modulus and low-molecular-weight acrylic ester modified methyl phenyl silicone oil is taken as a main body, the mechanical property is adjusted by the low-modulus and high-molecular-weight acrylic ester modified methyl phenyl silicone oil, and then the viscosity is adjusted by the active acrylic ester monomer; the optical fiber has the advantages of simple synthesis process, excellent heat resistance and low temperature resistance, adjustable refractive index and mechanical property, easy stripping of an optical fiber coating and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber coatings, and in particular to a high temperature resistant light-cured optical fiber coating and a preparation method thereof. Background Art

[0002] High temperature resistant optical fiber is a kind of optical fiber transmission equipment that can be used in high temperature environment. It uses special materials and manufacturing processes, which can maintain its normal working state in high temperature environment, and is suitable for application in some special fields. In recent years, optical fibers for nuclear power plants, drilling exploration, and aircraft have become more and more popular. These high temperature scenes require the use of special high temperature resistant optical fibers, which are generally coated and produced using thermosetting systems such as polyimide and silicone modification. However, the raw material cost is high, the production speed is slow, the energy consumption of the production process is high, the optical fiber produced has large attenuation, and the low temperature resistance is poor. There are also photocuring coatings modified with inorganic fillers, but their glass transition temperature is high and cannot be used in low temperature fields at the same time. In addition, the coatings are easy to settle and storage is unstable.

[0003] The key to the materials and manufacturing process of high-temperature resistant optical fiber mainly includes two aspects: optical fiber core and optical fiber coating. The optical fiber core is usually made of high-temperature glass and ceramic materials, which have excellent high-temperature stability and anti-oxidation properties, and can maintain its normal working state for a long time in a high-temperature environment. The optical fiber coating uses high-temperature resistant materials such as modified acrylate, silicone resin and polyimide resin to protect the optical fiber core from external factors.

[0004] Chinese invention patents CN115466566A and CN113402967B both contain silicone-modified acrylate systems, and composite acrylate monomers or UV silicone monomers to form a high-temperature resistant coating system. The acrylate content in the system is relatively high, but the actual temperature resistance and yellowing resistance are still worse than those of systems with high silicone content.

[0005] Japanese patents JP1989286939A and JP1991074463A use ultraviolet curing mercapto alkyl polyorganosiloxane compositions to prepare high temperature resistant silicone coatings, which have good high temperature resistance and can prepare high refractive index UV silicone resins. However, the mercapto type synthesis route in the preparation method is cumbersome and has high requirements, and an organic solvent is required, which makes post-processing difficult.

[0006] Generally speaking, silicone has poor mechanical properties, including poor strength, modulus and cohesion. As a UV silicone resin, it is difficult to achieve the characteristics of flexibility and a certain modulus. As an optical fiber coating, it is prone to low modulus and poor cohesion, and it is easy to leave residues after optical fiber stripping. There have been attempts to use high-functional acrylate monomers to compound it to improve the mechanical properties, but the curing shrinkage is too large, affecting the optical fiber performance. Summary of the invention

[0007] The present invention solves the deficiencies in the prior art and provides a light-cured high-temperature resistant optical fiber coating having the advantages of simple synthesis process, excellent heat resistance and low-temperature resistance, adjustable refractive index and mechanical properties, and easy stripping of the optical fiber coating.

[0008] The technical solution adopted to achieve the above-mentioned purpose of the present invention is:

[0009] A light-cured high-temperature resistant optical fiber coating, the coating comprising the following components by weight percentage:

[0010]

[0011] Furthermore, the 2.5% specific modulus of the low modulus acrylate-modified methylphenyl silicone oil is between 0.1 and 0.4 MPa.

[0012] Furthermore, the low modulus acrylate-modified methylphenyl silicone oil is synthesized from (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl)acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (vi) pure water; wherein the proportion of (methyl)acryloxymethyldimethoxysilane is 1 to 8 mol%.

[0013] Furthermore, the 2.5% specific modulus of the high modulus acrylate-modified methylphenyl silicone oil is between 2.0 and 6.0 MPa.

[0014] Furthermore, the high modulus acrylate-modified methylphenyl silicone oil is synthesized from (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl)acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (vi) pure water; wherein the proportion of (methyl)acryloxymethyldimethoxysilane is 20 to 40 mol%.

[0015] Furthermore, the acrylate monomer is at least one of isobornyl (meth) acrylate, 3,3,5-trimethylcyclohexyl acrylate, dicyclopentyl methacrylate, tricyclodecane dimethanol diacrylate, dioxane dimethanol diacrylate, and tricyclodecane dimethanol dimethacrylate.

[0016] Furthermore, the photoinitiator is selected from at least one of 1173, 184, TPO-L and 819.

[0017] Furthermore, the antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, Irganox L135, Irganox L57, and Irganox 1035.

[0018] The present invention also provides a preparation process of acrylate-modified methylphenyl silicone oil, comprising the following steps: weighing the following components: (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl)acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (viii) i) Pure water synthesis, put into a reactor, heat to 50-70°C and then hydrolyze for 1-3 hours, then heat to 80-110°C, and reduce the pressure to below -0.08Mpa for condensation for 1-2 hours, then continue to heat to 140-160°C to decompose the catalyst tetramethylammonium hydroxide. The colorless and transparent product obtained after the reaction is completed is acrylate-modified methylphenyl silicone oil. By adjusting the addition amount of (meth)acryloxymethyldimethoxysilane, acrylate-modified methylphenyl silicone oil with different high and low moduli can be obtained.

[0019] The present invention also provides a preparation process of the above-mentioned light-cured high-temperature resistant optical fiber coating, comprising the following steps: weighing each component according to weight percentage, fully stirring and filtering to obtain the light-cured high-temperature resistant optical fiber coating.

[0020] Compared with the prior art, the high-temperature resistant photocurable optical fiber coating provided by the present invention has the following advantages: 1. The present invention adopts a compound of high and low modulus acrylate-modified methylphenyl silicone oil, with high modulus and low molecular weight acrylate-modified methylphenyl silicone oil as the main body, and adjusts the mechanical properties by low modulus and high molecular weight acrylate-modified methylphenyl silicone oil, and then adjusts the viscosity with active acrylate monomers, and forms a tough coating with a certain strength after UV curing in combination with photoinitiators and antioxidants (i.e., heat-resistant additives). It has good high and low temperature resistance, can be baked at 200°C for more than 24 hours without abnormalities, and can pass aging tests such as high and low temperature cycles of wet heat and wet freeze. There is no residue when the optical fiber is stripped, avoiding the use of high-functional monomers to affect the performance of the optical fiber.

[0021] 2. In the present invention, when synthesizing low modulus acrylate-modified methylphenyl silicone oil, the crosslinking points are less and the molecular weight is larger, which can provide the main flexibility and low temperature resistance. The characteristic modulus is 0.1-0.4MPa, and the proportion of (meth)acryloxymethyldimethoxysilane is 1-8mol%. If the proportion of (meth)acryloxymethyldimethoxysilane is lower than 1mol%, the curing efficiency will be low and the surface will be sticky. When synthesizing high modulus acrylate-modified methylphenyl silicone oil, the crosslinking points are more and the molecular weight is smaller, which can improve the mechanical properties, cohesion and curing speed of the coating and reduce the residue when the optical fiber coating is stripped. The characteristic modulus is 2.0-6.0MPa, and the proportion of (meth)acryloxymethyldimethoxysilane is 20-40mol%. If the proportion of (meth)acryloxymethyldimethoxysilane is higher than 40mol%, the crosslinking is too high and it is easy to crack in a long-term high temperature environment. By compounding high-modulus acrylate-modified methylphenyl silicone oil with low-modulus acrylate-modified methylphenyl silicone oil, the combined mechanical properties can be adjusted to meet the needs of different scenarios, and the heat resistance of the composite formula is better than the heat resistance of a single acrylate-modified methylphenyl silicone oil with the same modulus.

[0022] 3. In the present invention, when synthesizing acrylate-modified methylphenyl silicone oil, the refractive index and mechanical properties of the coating can be adjusted by adjusting the proportion of phenyl silicone resin and the proportion of heat-resistant high Tg monomer in the silicone resin to meet the needs of different target groups; and no organic solvent is involved in the entire synthesis process, which is energy-saving and environmentally friendly, and no post-processing is required. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0024] Synthesis Example 1

[0025] 238.0 g of octaphenylcyclotetrasiloxane, 148.3 g of octamethylcyclotetrasiloxane, 36 g of pure water, 43.7 g of acryloxymethyldimethoxysilane, 3.0 g of tetramethylammonium hydroxide pentahydrate and 2.3 g of octamethyltrisiloxane were put into a reactor, heated to 60°C for hydrolysis for 2 hours, then heated to 95°C, reduced pressure to below -0.08 MPa, condensed for 1.5 hours, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., high modulus acrylate-modified methylphenyl silicone oil (LH1), whose 2.5% specific modulus is 2.1 MPa.

[0026] Synthesis Example 2

[0027] 238.0 g of octaphenylcyclotetrasiloxane, 198.7 g of octamethylcyclotetrasiloxane, 36 g of pure water, 6.6 g of acryloxymethyldimethoxysilane, 3.1 g of tetramethylammonium hydroxide pentahydrate and 1.2 g of octamethyltrisiloxane were put into a reaction kettle, heated to 60°C for hydrolysis for 2 hours, then heated to 95°C, reduced pressure to below -0.08 MPa, condensed for 1.5 hours, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., low modulus acrylate modified methylphenyl silicone oil (HL2), whose 2.5% specific modulus is 0.2 MPa.

[0028] Synthesis Example 3

[0029] 238.0g of octaphenylcyclotetrasiloxane, 118.7g of octamethylcyclotetrasiloxane, 36g of pure water, 65.5g of (meth)acryloxymethyldimethoxysilane, 3.0g of tetramethylammonium hydroxide pentahydrate and 2.3g of octamethyltrisiloxane were put into a reactor, heated to 60°C for hydrolysis for 2h, then heated to 95°C, reduced pressure to below -0.08MPa, condensed for 1.5h, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., high modulus acrylate modified methylphenyl silicone oil (LH3), whose 2.5% specific modulus is 3.9MPa.

[0030] Example 1

[0031] Take 100 g of LH1, 50 g of HL2, 10 g of IBOA, 4 g of TPO-L, and 0.16 g of Irganox L135, stir and mix them, and then filter to obtain the light-cured high-temperature resistant optical fiber coating A1.

[0032] Example 2

[0033] Take 100 g of LH3, 50 g of HL2, 10 g of IBOA, 4 g of TPO-L, and 0.16 g of Irganox L135, stir and mix them, and then filter to obtain the light-cured high-temperature resistant optical fiber coating A2.

[0034] Example 3

[0035] Take 100 g of LH3, 70 g of HL2, 30 g of IBOA, 5 g of TPO-L, and 0.2 g of Irganox L135, stir and mix them, and then filter to obtain the light-cured high-temperature resistant optical fiber coating A3.

[0036] Comparative Synthesis Example 1

[0037] 238.0g of octaphenylcyclotetrasiloxane, 59.3g of octamethylcyclotetrasiloxane, 36g of pure water, 109.2g of acryloxymethyldimethoxysilane, 2.9g of tetramethylammonium hydroxide pentahydrate and 1.2g of octamethyltrisiloxane were put into a reaction kettle, heated to 60°C for hydrolysis for 2h, then heated to 95°C, reduced pressure to below -0.08MPa, condensed for 1.5h, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., high modulus acrylate modified methylphenyl silicone oil (LH4), whose 2.5% specific modulus is 9.2MPa.

[0038] Comparative Synthesis Example 2

[0039] 238.0 g of octaphenylcyclotetrasiloxane, 206.2 g of octamethylcyclotetrasiloxane, 36 g of pure water, 1.1 g of acryloxymethyldimethoxysilane, 3.1 g of tetramethylammonium hydroxide pentahydrate and 1.2 g of octamethyltrisiloxane were put into a reactor, heated to 60°C for hydrolysis for 2 h, then heated to 95°C, reduced pressure to below -0.08 MPa, condensed for 1.5 h, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., low modulus acrylate modified methylphenyl silicone oil (HL5), whose 2.5% specific modulus is too low to be measured.

[0040] Comparative Synthesis Example 3

[0041] 238.0 g of octaphenylcyclotetrasiloxane, 172.0 g of octamethylcyclotetrasiloxane, 36 g of pure water, 26.2 g of acryloxymethyldimethoxysilane, 3.1 g of tetramethylammonium hydroxide pentahydrate and 1.2 g of octamethyltrisiloxane were put into a reaction kettle, heated to 60°C for hydrolysis for 2 hours, then heated to 95°C, reduced pressure to below -0.08 MPa, condensed for 1.5 hours, and then heated to 150°C to decompose the catalyst to obtain a colorless and transparent product, i.e., medium modulus acrylate-modified methylphenyl silicone oil (HL6), whose 2.5% specific modulus is 0.9 MPa.

[0042] Comparative Example 1

[0043] Take 100 g of LH4, 50 g of HL2, 10 g of IBOA, 4 g of TPO-L, and 0.16 g of Irganox L135, stir and mix them, and then filter to obtain the light-cured high-temperature resistant optical fiber coating B1.

[0044] Comparative Example 2

[0045] Take 100 g of LL1, 50 g of HL5, 10 g of IBOA, 4 g of TPO-L, and 0.16 g of Irganox L135, stir and mix them evenly, and then filter to obtain the light-cured high-temperature resistant optical fiber coating B2.

[0046] Comparative Example 3

[0047] 150 g of HL6, 10 g of IBOA, 4 g of TPO-L, and 0.16 g of Irganox L135 were taken, stirred and mixed, and then filtered to obtain a light-cured high-temperature resistant optical fiber coating B3.

[0048] Take each of the light-cured high-temperature resistant optical fiber coatings prepared in the above examples and comparative examples, apply a 200um coating film, and irradiate with an energy of 500mJ / cm under an electrodeless lamp. 2 After curing, the product was placed in a 200°C oven for 24 hours. The appearance and 2.5% modulus change before and after baking were compared. The results are shown in the following table:

[0049]

[0050]

[0051] It can be seen from the above table that within the appropriate range of (meth)acryloyloxy groups, by compounding high and low modulus acrylate-modified methylphenyl silicone oils, the cured light-cured high-temperature resistant optical fiber coating has good high-temperature resistance, is resistant to high temperatures and does not crack, and has a small change in modulus before and after baking, thus avoiding the increase in internal stress due to large changes in modulus and thus affecting the performance of the optical fiber. It can be seen from Comparative Example B1 and Example A1 that an excessively high ratio of (meth)acryloxy groups can lead to a large change in modulus after high-temperature baking, and then excessive stress in the coating may cause cracking; it can be seen from Comparative Example B2 and A1 that an excessively low ratio of (meth)acryloxy groups leads to a low degree of UV curing crosslinking, which cannot provide a good protective effect on the optical fiber, and the surface is soft and sticky; by comparing B3 with A1, A2, and A3, it can be seen that the use of a single silicone resin has poor flexibility and heat resistance under the premise of ensuring a certain modulus compared to a compound; by comparing A1, A2, and A3, it can be seen that the UV-curing silicone composition with different moduli can be adjusted by adjusting the ratio of (meth)acryloxy groups and the content of acrylate monomers in the coating, thereby meeting the needs of different types.

Claims

1. A light-cured high temperature resistant optical fiber coating, characterized in that: The coating comprises the following components by weight percentage:

2. The light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that: The 2.5% specific modulus of the low modulus acrylate-modified methylphenyl silicone oil is between 0.1 and 0.4 MPa.

3. The light-curable high temperature resistant optical fiber coating according to claim 2, characterized in that: The low modulus acrylate-modified methylphenyl silicone oil is synthesized from (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl)acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (vi) pure water; wherein the proportion of (methyl)acryloxymethyldimethoxysilane is 1 to 8 mol%.

4. The light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that: The 2.5% specific modulus of the high modulus acrylate-modified methylphenyl silicone oil is between 2.0 and 6.0 MPa.

5. The light-curable high temperature resistant optical fiber coating according to claim 4, characterized in that: The high modulus acrylate-modified methylphenyl silicone oil is synthesized from (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl)acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (vi) pure water; wherein the proportion of (methyl)acryloxymethyldimethoxysilane is 20-40 mol%.

6. The light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that: The acrylate monomer is at least one of isobornyl (meth) acrylate, 3,3,5-trimethylcyclohexyl acrylate, dicyclopentyl methacrylate, tricyclodecane dimethanol diacrylate, dioxane dimethanol diacrylate, and tricyclodecane dimethanol dimethacrylate.

7. The light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that: The photoinitiator is selected from at least one of 1173, 184, TPO-L and 819.

8. The light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that: The antioxidant is selected from at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, Irganox L135, Irganox L57 and Irganox 1035.

9. A process for preparing acrylate-modified methylphenyl silicone oil, characterized in that The following steps are involved: The following components are weighed: (i) at least one of dimethyldimethoxysilane and octamethylcyclotetrasiloxane, (ii) at least one of diphenyldimethoxysilane, tetramethyltetraphenylcyclotetrasiloxane and octaphenylcyclotetrasiloxane, (iii) (methyl) acryloxymethyldimethoxysilane, (iv) tetramethylammonium hydroxide, (v) at least one of hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and (vi) pure water, and put into a reaction kettle, heated to 50-70° C. and then hydrolyzed for 1-3 hours, then heated to 80-110° C. and decompressed to below -0.08 MPa for condensation for 1-2 hours, then heated to 140-160° C. and decomposed the catalyst tetramethylammonium hydroxide. After the reaction is completed, the colorless and transparent product obtained is acrylate-modified methylphenyl silicone oil. By adjusting the amount of (meth)acryloxymethyldimethoxysilane added, acrylate-modified methylphenyl silicone oil with different high and low moduli can be obtained.

10. The process for preparing the light-curable high temperature resistant optical fiber coating according to claim 1, characterized in that The following steps are involved: The components are weighed according to weight percentage, fully stirred and filtered to obtain the light-cured high-temperature resistant optical fiber coating.

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