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

Abstract

The invention provides a photocuring high-temperature-resistant optical fiber inner layer coating and a preparation method thereof. The coating comprises the following components in percentage by weight: 40-80% of a modified polyurethane acrylate oligomer, 12-40% of an acrylate monomer, 0.5-6% of a photoinitiator, 0.05-1% of an antioxidant and 0.05-1% of a coupling agent, the modified polyurethane acrylate oligomer is prepared from the following components: polyester glycol, diisocyanate, hydroxyl acrylate, a polycondensation catalyst, a polymerization inhibitor, monoisocyanate and a basic catalyst. According to the invention, polyurethane acrylate matrix resin synthesized from polyester diol is modified, and a large number of branched chains are introduced to a main chain, so that water vapor shielding and blocking effects on ester bonds are achieved, and the damp and heat resistance of the polyurethane acrylate matrix resin is improved. The final product has the advantages of good high and low temperature resistance, good humidity and heat resistance, good flexibility and low glass transition temperature.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber coatings, and in particular to a high-temperature resistant light-cured optical fiber inner layer 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. In addition to meeting some basic performance indicators of ordinary optical fiber, it can also maintain its normal working state in high temperature environment, and is suitable for applications in some special fields.

[0003] As a composite material, optical fiber is composed of an inner quartz part and an outer coating. The outer coating of conventional optical fiber is generally a conventional acrylic resin, and its operating temperature is generally -65 to 85°C. If it works in an environment above 85°C for a long time, it will cause damage to the optical fiber. In real life, there are many scenarios where optical fiber needs to work at high temperatures, such as mining industry, aerospace industry, military, oil and gas, and high-temperature medical applications. These high-temperature scenarios 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 production process has high energy consumption, the optical fiber produced has large attenuation, and poor low-temperature resistance. There are also photocurable coatings produced using epoxy resins and polycarbonates with good temperature resistance. Although the curing speed is fast, the modulus is large and the glass transition temperature is high, and the optical fiber produced by them also has large attenuation and poor low-temperature resistance.

[0004] In the invention CN117304777A, the main resins are epoxy acrylate oligomers and polycarbonate acrylate oligomers. Although the two oligomers have good high temperature resistance, they have large modulus and high glass transition temperature, which will cause the produced optical fiber to have large attenuation and poor low temperature resistance. Summary of the invention

[0005] The present invention solves the deficiencies in the prior art and provides a light-cured, high-temperature resistant optical fiber inner layer coating, which has the advantages of simple synthesis process, good resistance to high and low temperatures and moisture and heat, good flexibility, and low glass transition temperature, and can protect the optical fiber in a wide temperature range and harsh environment.

[0006] The technical solution adopted to achieve the above-mentioned purpose of the present invention is:

[0007] A light-cured high-temperature resistant optical fiber inner layer coating, the coating comprising the following components by weight percentage:

[0008]

[0009]

[0010] The modified polyurethane acrylate oligomer is prepared by the following method: first, various components are taken: (i) polyester diol, (ii) diisocyanate, (iii) hydroxy acrylate, (iv) polycondensation catalyst, (v) inhibitor, (vi) monoisocyanate and (vii) alkaline catalyst, wherein the molar ratio of (i) polyester diol, (ii) diisocyanate, (iii) hydroxy acrylate and (vi) monoisocyanate is 1: (1.1-1.3): (0.2-0.6): (2.2-2.6) and (i) is added into a reaction kettle at room temperature. A polyester diol, (ii) a diisocyanate, (iv) a polycondensation catalyst and (v) a polymerization inhibitor are heated to 65-85° C. and stirred to react until the NCO% reaches a theoretical value; then (iii) a hydroxy acrylate is added, stirred at 65-85° C. and reacted until the NCO% is ≤0.15% to obtain a polyurethane acrylate oligomer; and (vi) a monoisocyanate and (vii) a basic catalyst are continuously added to the polyurethane acrylate oligomer, stirred at 65-85° C. and reacted until the NCO% is ≤0.15% to obtain the modified polyurethane acrylate oligomer.

[0011] Furthermore, the polyester diol has a glass transition temperature of ≤-50°C and a molecular weight of 200-1000, and the polyester diol is specifically at least one of polycaprolactone diol, AA-EG copolymerized polyester diol, AA-BG copolymerized polyester diol, AA-HD copolymerized polyester diol, and AA-NPG copolymerized polyester diol.

[0012] Further, the diisocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, methylene di(4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, and 4,4'-biphenyl diisocyanate.

[0013] Furthermore, the hydroxy acrylate is selected from at least one of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and neopentyl glycol mono(meth)acrylate.

[0014] Furthermore, the polycondensation catalyst is dibutyltin dilaurate, N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine or tetraisooctyl titanate; the polymerization inhibitor is at least one of tert-butylhydroquinone, p-hydroxyanisole, hydroquinone or o-methylhydroquinone; and the alkaline catalyst is at least one of triethylamine, dimethylethanolamine, diethylamine and trimethylamine.

[0015] Furthermore, the monoisocyanate is at least one of tert-butyl isocyanate, ethyl isocyanate, m-toluene isocyanate, amyl isocyanate, cyclohexyl isocyanate, and cyclooctyl isocyanate.

[0016] Furthermore, the acrylate monomer is at least one of isobornyl (meth) acrylate, 3,3,5-trimethylcyclohexyl acrylate, dicyclopentyl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofuran acrylate, benzyl acrylate, lauric acrylate, stearic acid acrylate, and isodecyl acrylate.

[0017] Furthermore, the photoinitiator is selected from at least one of 1173, 184, TPO-L and 819.

[0018] 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.

[0019] Furthermore, the coupling agent is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and γ-mercaptopropyltrimethoxysilane.

[0020] Compared with the prior art, the high temperature resistant light-cured optical fiber inner coating provided by the present invention has the following advantages: 1. The optical fiber inner coating made of polyurethane acrylate as the main resin of the present invention has a fast curing speed, and the raw material polyester polyol for synthesizing the main resin has good high temperature and low temperature resistance, and is cheap and easy to obtain. The polyurethane acrylate oligomer synthesized with polyester diols with good high and low temperature resistance has good flexibility and excellent high and low temperature resistance. The final product has the advantages of good high and low temperature resistance and wet heat resistance, good flexibility, and low glass transition temperature, and can protect the optical fiber in a wide temperature range and harsh environment.

[0021] 2. The present invention modifies the polyurethane acrylate main resin synthesized from the polyester polyol, introduces a large number of side chains into the main chain, plays a role in shielding and blocking the ester bond, and improves its ability to resist moisture and heat. The final product has the advantages of good resistance to high and low temperatures and moisture and heat, good flexibility, and low glass transition temperature, and can protect optical fibers in a wide temperature range and harsh environment. The optical fiber coating produced with this modified polyurethane acrylate oligomer as the main resin has a low 2.5% deformation modulus and glass transition temperature, excellent resistance to moisture and heat and high temperature aging, and the optical fiber produced with it has low attenuation, good microbending resistance and high and low temperature resistance, and can be used in a wider temperature range. DETAILED DESCRIPTION

[0022] 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.

[0023] Synthesis Example 1

[0024] At room temperature, 1 mol of polycaprolactone diol, 1.2 mol of isophorone diisocyanate, 0.8 g of dibutyltin dilaurate and 8 g of tert-butylhydroquinone were added to a reaction kettle, heated to 65-85°C with stirring, and reacted until NCO% reached the theoretical value; then 0.4 mol of hydroxyethyl acrylate was added, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain a polyurethane acrylate oligomer. 2.4 mol of tert-butyl isocyanate and 0.8 g of triethylamine were added to the polyurethane acrylate oligomer, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain the modified polyurethane acrylate oligomer (material L1).

[0025] Synthesis Example 2

[0026] At room temperature, 1 mol of polycaprolactone diol, 1.2 mol of toluene diisocyanate, 0.8 g of dibutyltin dilaurate and 8 g of tert-butylhydroquinone were added to a reaction kettle, heated to 65-85°C with stirring, and reacted until NCO% reached the theoretical value; then 0.4 mol of hydroxyethyl acrylate was added, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain a polyurethane acrylate oligomer. 2.4 mol of tert-butyl isocyanate and 0.8 g of triethylamine were added to the polyurethane acrylate oligomer, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain the modified polyurethane acrylate oligomer (material L2).

[0027] Synthesis Example 3

[0028] At room temperature, 1 mol of polycaprolactone diol, 1.2 mol of isophorone diisocyanate, 0.8 g of dibutyltin dilaurate and 8 g of tert-butylhydroquinone were added to a reaction kettle, heated to 65-85°C with stirring, and reacted until NCO% reached the theoretical value; then 0.4 mol of hydroxyethyl acrylate was added, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain a polyurethane acrylate oligomer. 2.4 mol of m-toluene isocyanate and 0.8 g of triethylamine were added to the polyurethane acrylate oligomer, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain the modified polyurethane acrylate oligomer (material L3).

[0029] Synthesis Example 4

[0030] At room temperature, 1 mol of AA-EG copolyester diol, 1.15 mol of hexamethylene diisocyanate, 0.8 g of N,N-dimethylbenzylamine and 8 g of p-hydroxyanisole are added to a reaction kettle, heated to 65-85° C. and stirred, and reacted until NCO% reaches a theoretical value; then 0.3 mol of 2-hydroxypropyl acrylate is added, stirred at 65-85° C., and reacted until NCO% is ≤ 0.15%, thereby obtaining a polyurethane acrylate oligomer. 2.5 mol of ethyl isocyanate and 0.8 g of trimethylamine are added to the polyurethane acrylate oligomer, stirred at 65-85° C., and reacted until NCO% is ≤ 0.15%, thereby obtaining the modified polyurethane acrylate oligomer.

[0031] Example 1

[0032] Take 65g of material L1, 30g of IDA (isodecyl acrylate), 4g of TPO-L, 0.5g of Irganox L135, and 0.5g of γ-methacryloxypropyltrimethoxysilane, stir and mix well, and then filter to obtain the light-cured high-temperature resistant optical fiber inner layer coating A1.

[0033] Example 2

[0034] Take 65 g of material L2, 30 g of IDA, 4 g of TPO-L, 0.5 g of Irganox L135, and 0.5 g of γ-methacryloxypropyltrimethoxysilane, stir and mix well, and then filter to obtain the light-cured high-temperature resistant optical fiber inner layer coating A2.

[0035] Example 3

[0036] Take 65 g of material L3, 30 g of IDA, 4 g of TPO-L, 0.5 g of Irganox L135, and 0.5 g of γ-methacryloxypropyltrimethoxysilane, stir and mix well, and then filter to obtain the light-cured high-temperature resistant optical fiber inner layer coating A3.

[0037] Example 4

[0038] Take 76 g of material L3, 20 g of IDA, 3 g of TPO-L, 0.45 g of Irganox L135, and 0.55 g of γ-methacryloxypropyltrimethoxysilane, stir and mix well, and then filter to obtain the light-cured high-temperature resistant optical fiber inner layer coating A4.

[0039] Comparative Synthesis Example 1

[0040] At room temperature, 1 mol of polycaprolactone diol, 1.2 mol of isophorone diisocyanate, 0.8 g of dibutyltin dilaurate and 8 g of tert-butylhydroquinone were added to a reaction kettle, heated to 65-85° C. and stirred, and reacted until NCO% reached the theoretical value; then 0.4 mol of hydroxyethyl acrylate was added, stirred at 65-85° C., and reacted until NCO% ≤ 0.15%, to obtain a polyurethane acrylate oligomer (material LL1). Different from Synthesis Example 1, the polyurethane acrylate oligomer was not modified.

[0041] Comparative Synthesis Example 2

[0042] At room temperature, 1 mol of polycarbonate diol, 1.2 mol of isophorone diisocyanate, 0.8 g of dibutyltin dilaurate and 8 g of tert-butylhydroquinone were added to a reaction kettle, heated to 65-85°C and stirred, and reacted until NCO% reached the theoretical value; then 0.4 mol of hydroxyethyl acrylate was added, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain a polyurethane acrylate oligomer. 2.4 mol of tert-butyl isocyanate and 0.8 g of triethylamine were added to the polyurethane acrylate oligomer, stirred at 65-85°C, and reacted until NCO% ≤ 0.15%, to obtain the modified polyurethane acrylate oligomer (material LL2). Different from Synthesis Example 1, the diol for synthesizing the polyurethane acrylate oligomer is polycarbonate diol.

[0043] Comparative Example 1

[0044] 65 g of material LL1, 30 g of IDA, 4 g of TPO-L, 0.5 g of Irganox L135, and 0.5 g of γ-methacryloxypropyltrimethoxysilane were mixed and stirred, and then filtered to obtain composition B1. Different from Example 1, material LL1 was not modified.

[0045] Comparative Example 2

[0046] 65 g of material LL2, 30 g of IDA, 4 g of TPO-L, 0.5 g of Irganox L135, and 0.5 g of γ-methacryloxypropyltrimethoxysilane were mixed and stirred, and then filtered to obtain composition B2. Different from Example 2, material LL2 was synthesized by using polycarbonate diol instead of polycaprolactone diol.

[0047] Take the above-prepared composition (A1, A2, A3, B1, B2), apply a 200um coating film, and irradiate it under an electrodeless lamp with an energy of 500mJ / cm 2 The cured film was cured to form a film. The cured film was tested for mechanical properties (tensile strength, elongation at break, 2.5% deformation modulus), glass transition temperature, wet heat aging (85°C / 85% RH*7d), and high temperature aging (200°C*8h). The results are shown in the following table:

[0048]

[0049] As shown in the table above, the compositions A1, A2, A3 prepared in the present invention have greatly improved resistance to wet heat aging compared with B1, and the wet heat aging change rate is very small, which can meet the wet heat resistance requirements of optical fiber coatings, indicating that the modification method of introducing a large number of side chains on the main chain of polyurethane acrylate oligomer improves the hydrolysis resistance of the polyurethane acrylate, so that the optical fiber coating produced by using it as the main resin can meet the wet heat aging requirements. Compared with compositions A1, A2, A3 and B2, although B2 has good resistance to wet heat aging and high temperature aging, its 2.5% deformation modulus and glass transition temperature are both high, while the 2.5% deformation modulus and glass transition temperature of A1, A2, and A3 are all at a lower level. The optical fiber produced by A1, A2, and A3 has low energy attenuation, better microbending resistance and low temperature resistance, and can be used in a wider temperature range.

Claims

1. A light-cured high-temperature resistant optical fiber inner layer coating, characterized in that: The coating comprises the following components by weight percentage: The modified polyurethane acrylate oligomer is prepared by the following method: first, various components are taken: (i) polyester diol, (ii) diisocyanate, (iii) hydroxy acrylate, (iv) polycondensation catalyst, (v) inhibitor, (vi) monoisocyanate and (vii) alkaline catalyst, wherein the molar ratio of (i) polyester diol, (ii) diisocyanate, (iii) hydroxy acrylate and (vi) monoisocyanate is 1: (1.1-1.3): (0.2-0.6): (2.2-2.6); (i) is added into a reaction kettle at room temperature; ) polyester diol, (ii) diisocyanate, (iv) polycondensation catalyst and (v) polymerization inhibitor, heat to 65-85° C. and stir, react until NCO% reaches the theoretical value; then add (iii) hydroxy acrylate, maintain stirring at 65-85° C. and react until NCO% ≤ 0.15%, thereby obtaining polyurethane acrylate oligomer; continue to add (vi) monoisocyanate and (vii) alkaline catalyst to the polyurethane acrylate oligomer, maintain stirring at 65-85° C. and react until NCO% ≤ 0.15%, thereby obtaining the modified polyurethane acrylate oligomer.

2. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The polyester diol has a glass transition temperature of ≤-50°C and a molecular weight of 200-1000. The polyester diol is specifically at least one of polycaprolactone diol, AA-EG copolymerized polyester diol, AA-BG copolymerized polyester diol, AA-HD copolymerized polyester diol, and AA-NPG copolymerized polyester diol.

3. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The diisocyanate is at least one of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, methylene di(4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylphenylene diisocyanate, and 4,4'-biphenyl diisocyanate.

4. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The hydroxy acrylate is selected from at least one of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and neopentyl glycol mono(meth)acrylate.

5. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The polycondensation catalyst is dibutyltin dilaurate, N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N'-dimethylpyridine or tetraisooctyl titanate; the polymerization inhibitor is at least one of tert-butylhydroquinone, p-hydroxyanisole, hydroquinone or o-methylhydroquinone; and the alkaline catalyst is at least one of triethylamine, dimethylethanolamine, diethylamine and trimethylamine.

6. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The monoisocyanate is at least one of tert-butyl isocyanate, ethyl isocyanate, m-toluene isocyanate, amyl isocyanate, cyclohexyl isocyanate, and cyclooctyl isocyanate.

7. The light-curable high temperature resistant optical fiber inner layer 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, 2-phenoxyethyl acrylate, tetrahydrofuran acrylate, benzyl acrylate, lauric acrylate, stearic acid acrylate, and isodecyl acrylate.

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

9. The light-curable high temperature resistant optical fiber inner layer 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.

10. The light-curable high temperature resistant optical fiber inner layer coating according to claim 1, characterized in that: The coupling agent is at least one of γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and γ-mercaptopropyltrimethoxysilane.

Images