Modified fluorine-containing novolac epoxy resin and preparation method thereof, photoresist solution and optical waveguide device

Abstract

The invention provides modified fluorine-containing novolac epoxy resin and a preparation method thereof, a photoresist solution and an optical waveguide device, and belongs to the field of optical waveguide materials. And the flexibility of the modified fluorine-containing novolac epoxy resin is improved by an alkyl chain or a-C-F-chain. The fluorine content of the resin is further increased and the proportion of C-H bonds is further reduced after the fluorine-containing organic acid is used for modification, so that the optical transparency of the material in an optical communication band is increased, the absorption loss is reduced, and an optical waveguide device prepared from the material can be directly used in an optical interconnection device. The technical route provided by the invention is simple in reaction process and low in equipment requirement, and can be used for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of optical waveguide materials, and particularly to a modified fluorinated phenolic epoxy resin, a preparation method thereof, a photoresist solution, and an optical waveguide device. Background Art

[0002] Low-loss optical waveguide materials are one of the core materials in optical communication and optical interconnection technologies. However, most of the phenolic epoxy resin series photoresists commonly used to prepare optical waveguide materials at present are rigid structural molecules. The prepared optical waveguide materials have disadvantages such as poor material toughness and high optical loss, and are prone to end face cracking problems during subsequent device grinding and polishing processes, which also lead to large end face coupling losses of optical communication devices. Moreover, with the development of flexible electronics technology, optical waveguide materials are required to have a certain degree of flexibility, while the rigid structure of phenolic epoxy resin cannot be applied to the field of flexible optical waveguides. Summary of the Invention

[0003] The present invention provides a modified fluorinated phenolic epoxy resin, a preparation method thereof, a photoresist solution, and an optical waveguide device. The modified fluorinated phenolic epoxy resin of the present invention has excellent flexibility and low transmission loss.

[0004] The present invention provides a modified fluorinated phenolic epoxy resin having a structural formula shown in Formula I: Formula I; The R includes -COC x H 2x+1 、-COC x F 2x+1 or -COC x H 2x+1 C y F 2y+1 ; The x = 0 to 15, and the y = 0 to 15; The n ≥ 1.

[0005] Preferably, the n = 3 to 10.

[0006] The present invention also provides a preparation method of the modified fluorinated phenolic epoxy resin according to the above technical solution, including the following steps: Mix an acid, a hexafluorobisphenol A type phenolic epoxy resin, a basic catalyst, and a polar organic solvent, and then carry out a grafting reaction to obtain the modified fluorinated phenolic epoxy resin; The chemical formula of the acid includes CH 2x+1 COOH, CF 2x+1 COOH or CH 2x+1 C y F 2y+1 COOH.

[0007] Preferably, the number-average molecular weight of the hexafluorobisphenol A type phenolic epoxy resin is 500 to 3000, the degree of polymerization is 3 to 10, the epoxy equivalent is 220 to 500 g / mol, and the softening point is 65 to 70 °C.

[0008] Preferably, the molar ratio of the acid to the amount of epoxy groups in the hexafluorobisphenol A type phenolic epoxy resin is 0.1 to 0.8:1.

[0009] Preferably, the basic catalyst includes one or more of NaOH, KOH, LiOH, aniline, benzylamine, NBu4Br, NBu4F, NBu4OH, and NMe4OH.

[0010] Preferably, the molar ratio of the acid to the basic catalyst is 0.5 to 10:1.

[0011] Preferably, the polar organic solvent includes one or more of dichloromethane, petroleum ether, ethyl acetate, butyl acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether.

[0012] The present invention also provides a photoresist solution, which includes the following raw materials by mass fraction: Modified fluorinated phenolic epoxy resin 70 - 75%; Photoinitiator 0.7 - 1%; Polar organic solvent 23 - 28%; The modified fluorinated phenolic epoxy resin is one or more of the modified fluorinated phenolic epoxy resins described in the above technical solution or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in the above technical solution.

[0013] Preferably, the photoinitiator includes one or more of iodonium salts, triphenylsulfonium phosphate, triphenylsulfonium antimonate, triphenylsulfonium trifluoromethanesulfonate, and triphenylsulfonium methanesulfonate.

[0014] The present invention also provides an optical waveguide device, which includes a top cladding, a core layer, and a bottom cladding stacked in sequence; By mass fraction, the preparation raw materials of the top cladding include: First modified fluorinated phenolic epoxy resin 70 - 75%; The mass content of the first modified fluorinated phenolic epoxy resin in the top cladding is greater than the mass content of the third modified fluorinated phenolic epoxy resin in the bottom cladding; First photoinitiator 0.7 - 1%; First polar organic solvent 23 - 28%; By mass fraction, the preparation raw materials of the core layer include: The second modified fluorinated phenolic epoxy resin: 70 - 75%; The second photoinitiator: 0.7 - 1%; The second polar organic solvent: 20 - 28%; In terms of mass fraction, the raw materials for preparing the lower cladding include: The third modified fluorinated phenolic epoxy resin: 70 - 75%; The third photoinitiator: 0.7 - 1%; The third polar organic solvent: 20 - 28%; The first modified fluorinated phenolic epoxy resin, the second modified fluorinated phenolic epoxy resin, and the third modified fluorinated phenolic epoxy resin are independently one or more of the modified fluorinated phenolic epoxy resins described in the above technical solution or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in the above technical solution; and the refractive index of the second modified fluorinated phenolic epoxy resin is higher than that of the third modified fluorinated phenolic epoxy resin.

[0015] The alkyl chain or -C-F- chain increases the flexibility of the modified fluorinated phenolic epoxy resin. The optical absorption of the C-F bond is very small. Therefore, when modified with fluorinated organic acids, the fluorine content of the resin will further increase, and the proportion of C-H bonds will further decrease, thereby increasing the optical transparency of the material in the optical communication band and reducing the absorption loss. The optical waveguide device prepared therefrom can be directly used in optical interconnection devices.

[0016] The fluorine content of the modified fluorinated phenolic epoxy resin of the present invention can be adjusted as needed, and the refractive index can also be adjusted, so that the refractive index range of the resin is larger and the numerical aperture is better matched.

[0017] The reaction process of the technical route described in the present invention is simple, has low requirements for equipment, and can be used for large-scale industrial production.

[0018] Due to different requirements for the performance of waveguide devices in optical communication, and the price of hydrofluoric acid is generally high. Therefore, when the performance requirements for optical devices in the application field of the device are not high, the present invention selects alkyl chain organic acids without fluorine or with low fluorine content for chemical modification of the resin to reduce the production cost of the photoresist. Description of the Drawings

[0019] Figure 1 1H NMR spectra of hexafluorobisphenol A type phenolic epoxy resin grafted with different types of alkyl chain carboxylic acids; Figure 2 1H NMR spectra of hexafluorobisphenol A type phenolic epoxy resin grafted with different proportions of perfluorovaleric acid; Figure 3 UV-Vis-NIR spectra of different types of perfluorocarboxylic acid modified resins. Detailed Embodiments

[0020] The present invention provides a modified fluorinated phenolic epoxy resin, which has a structural formula shown in Formula I: Formula I; The R includes -COC x H 2x+1 、-COC x F 2x+1 or -COC x H 2x+1 C y F 2y+1 ; The x = 0 to 15, and the y = 0 to 15; The n ≥ 1.

[0021] In a specific embodiment of the present invention, the n is preferably 3 to 10. In a specific embodiment of the present invention, the n can be 3, 4, 5, 6, 7, 8, 9 or 10.

[0022] In a specific embodiment of the present invention, the x can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15; the y can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0023] The present invention also provides a preparation method of the modified fluorinated phenolic epoxy resin according to the above technical solution, comprising the following steps: Mix an acid, a hexafluorobisphenol A phenolic epoxy resin, a basic catalyst and a polar organic solvent, and then carry out a graft reaction to obtain the modified fluorinated phenolic epoxy resin; The chemical formula of the acid includes C x H 2x+1 COOH, C x F 2x+1 COOH or C x H 2x+1 C y F 2y+1 COOH.

[0024] In the present invention, the molar ratio of the acid to the epoxy group in the hexafluorobisphenol A phenolic epoxy resin is preferably 0.1 to 0.8:1. In a specific embodiment of the present invention, the molar ratio of the acid to the hexafluorobisphenol A phenolic epoxy resin can be 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1 or 0.8:1; the chemical formula of the acid includes C x H 2x+1 COOH, C x F 2x+1 COOH or Cx H 2x+1 C y F 2y+1 COOH; The acid preferably includes one or more of butyric acid, caproic acid, perfluorobutyric acid, perfluorohexanoic acid, perfluorooctanoic acid, heptafluorooctanoic acid, heptanoic acid, perfluoroheptanoic acid, and heptafluoroheptanoic acid; The epoxy equivalent of the hexafluorobisphenol A type phenolic epoxy resin is preferably 220-500 g / mol, the softening point is preferably 65-70 °C, the molecular weight is preferably 500-3000, and the degree of polymerization is preferably 3-10. In specific embodiments of the present invention, the epoxy equivalent can be 220 g / mol, 250 g / mol, 280 g / mol, 300 g / mol, 350 g / mol, 400 g / mol, 450 g / mol, 480 g / mol, or 500 g / mol, the softening point can be 65 °C, 66 °C, 67 °C, 68 °C, 69 °C, or 70 °C, the molecular weight can be 500, 800, 1000, 1200, 1500, 1800, 2000, 2200, 2500, 2800, or 3000, and the degree of polymerization can be 3, 4, 5, 6, 7, 8, 9, or 10.

[0025] In the present invention, the molar ratio of the acid to the basic catalyst is preferably 0.5-10:1. In specific embodiments of the present invention, the molar ratio can be 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1; The basic catalyst preferably includes one or more of NaOH, KOH, LiOH, aniline, benzylamine, NBu4Br, NBu4F, NBu4OH, and NMe4OH.

[0026] In the present invention, the solid-liquid ratio of the hexafluorobisphenol A type phenolic epoxy resin to the polar organic solvent is preferably 4 g:9 mL; The polar organic solvent preferably includes one or more of dichloromethane, petroleum ether, ethyl acetate, butyl acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, ethylene glycol methyl ether, and propylene glycol methyl ether.

[0027] In the present invention, the temperature of the grafting reaction is preferably 80-120 °C, and the time is preferably 2-10 h. In specific embodiments of the present invention, the temperature of the grafting reaction can be 80 °C, 90 °C, 100 °C, 110 °C, or 120 °C, and the time can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, or 10 h.

[0028] In the present invention, the grafting reaction is preferably carried out in a protective atmosphere, and the protective atmosphere preferably includes nitrogen.

[0029] In the present invention, the grafting reaction is preferably carried out under stirring conditions.

[0030] After the grafting reaction, the present invention preferably further comprises: washing and concentrating the product obtained from the grafting reaction, then mixing the obtained solid with hydrochloric acid to neutralize the basic catalyst, separating the solid and liquid, and then washing and drying the obtained solid.

[0031] The present invention also provides a photoresist solution, which comprises the following raw materials by mass fraction: Modified fluorinated phenolic epoxy resin 70 - 75%; Photoinitiator 0.7 - 1%; Polar organic solvent 23 - 28%; The modified fluorinated phenolic epoxy resin is one or more of the modified fluorinated phenolic epoxy resins described in the above technical solutions or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in the above technical solutions.

[0032] In the present invention, by mass fraction, the raw materials of the photoresist solution include 70 - 75% of modified fluorinated phenolic epoxy resin, specifically 70%, 71%, 72%, 73%, 74% or 75%.

[0033] In the present invention, by mass fraction, the raw materials of the photoresist solution include 0.7 - 1% of photoinitiator. In specific embodiments of the present invention, the mass fraction of the photoinitiator in the raw materials of the photoresist solution can be 0.7%, 0.8%, 0.9% or 1%; the photoinitiator preferably includes one or more of iodonium salts, triphenylsulfonium phosphate, triphenylsulfonium antimonate, triphenylsulfonium trifluoromethanesulfonate and triphenylsulfonium methanesulfonate.

[0034] In the present invention, by mass fraction, the raw materials of the photoresist solution include 23 - 28% of polar organic solvent, specifically 23%, 24%, 25%, 26%, 27% or 28%; the polar organic solvent preferably includes one or more of dichloromethane, petroleum ether, ethyl acetate, butyl acetate, toluene, xylene, butanone, cyclopentanone, ethylene glycol methyl ether and propylene glycol methyl ether.

[0035] The present invention also provides an optical waveguide device, which includes a top cladding, a core layer and a bottom cladding stacked in sequence; By mass fraction, the preparation raw materials of the top cladding include: First modified fluorinated phenolic epoxy resin 70 - 75%; The mass content of the first modified fluorinated phenolic epoxy resin in the top cladding is greater than the mass content of the third modified fluorinated phenolic epoxy resin in the bottom cladding; First photoinitiator 0.7 - 1%; First polar organic solvent 23 - 28%; In terms of mass fraction, the raw materials for preparing the core layer include: The second modified fluorinated phenolic epoxy resin: 70 - 75%; The second photoinitiator: 0.7 - 1%; The second polar organic solvent: 23 - 28%; In terms of mass fraction, the raw materials for preparing the lower cladding layer include: The third modified fluorinated phenolic epoxy resin: 70 - 75%; The third photoinitiator: 0.7 - 1%; The third polar organic solvent: 23 - 28%; The first modified fluorinated phenolic epoxy resin, the second modified fluorinated phenolic epoxy resin, and the third modified fluorinated phenolic epoxy resin are independently one or more of the modified fluorinated phenolic epoxy resins described in the above technical solution or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in the above technical solution; and the refractive index of the second modified fluorinated phenolic epoxy resin is higher than that of the third modified fluorinated phenolic epoxy resin.

[0036] In the present invention, it is preferred that the first modified fluorinated phenolic epoxy resin has the same resin type as the third modified fluorinated phenolic epoxy resin.

[0037] In the present invention, the mass fractions of the first modified fluorinated phenolic epoxy resin, the second modified fluorinated phenolic epoxy resin, and the third modified fluorinated phenolic epoxy resin are preferably independently the mass fractions of the modified fluorinated phenolic epoxy resin in the photoresist solution; The types and mass fractions of the first photoinitiator, the second photoinitiator, and the third photoinitiator are preferably independently the types and mass fractions of the photoinitiator in the photoresist solution; The types and mass fractions of the first polar organic solvent, the second polar organic solvent, and the third polar organic solvent are preferably independently the types and mass fractions of the modified fluorinated phenolic epoxy resin in the photoresist solution.

[0038] The present invention also provides a preparation method for the optical waveguide device described in the above technical solution, which preferably includes the following steps: Mix the raw materials for preparing the lower cladding layer, coat them on the substrate, and then perform the first baking, the first exposure, and the first curing to form the lower cladding layer; Mix the raw materials for preparing the core layer, coat them on the surface of the lower cladding layer, and then perform the second baking, the second exposure, the third curing, development, washing, drying, and the fourth curing to form the core layer; Mix the raw materials for preparing the upper cladding layer, coat them on the surface of the core layer, and then perform the third baking, the third exposure, and the fifth curing to form the upper cladding layer, thus obtaining the optical waveguide device.

[0039] In the present invention, the raw materials for preparing the lower cladding are mixed and then coated on a substrate, followed by first baking, first exposure, and first curing to form the lower cladding.

[0040] In the present invention, the substrate preferably comprises a silicon wafer, an epoxy resin board, glass, polyimide, or a polyester resin board.

[0041] In the present invention, the coating preferably comprises pouring the raw materials for preparing the lower cladding onto the substrate and then placing it in a spin coater for coating.

[0042] In the present invention, the rotation speed of the spin coater is preferably 300 - 3000 r / min. In specific embodiments of the present invention, the rotation speed can be 300 r / min, 500 r / min, 800 r / min, 1000 r / min, 1200 r / min, 1500 r / min, 2000 r / min, 2500 r / min, or 3000 r / min.

[0043] In the present invention, the temperature of the first baking is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the first baking can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0044] Before the first exposure after the first baking, the present invention preferably restores the optical waveguide material obtained after the first baking to room temperature.

[0045] In the present invention, the wavelength of the light used in the first exposure is preferably 365 nm, the light intensity is preferably 20 mW / cm 2 , and the irradiation time is preferably 0.1 - 60 s. In specific embodiments of the present invention, the irradiation time can be 0.1 s, 5 s, 10 s, 20 s, 30 s, 40 s, 50 s, or 60 s.

[0046] In the present invention, the temperature of the first curing is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the first curing can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0047] After forming the lower cladding, the present invention mixes the raw materials for preparing the core layer and then coats them on the surface of the lower cladding, followed by second baking, second exposure, third curing, developing, washing, drying, and fourth curing to form the core layer.

[0048] In the present invention, the coating preferably comprises pouring the raw materials for preparing the core layer onto the surface of the lower cladding and then placing it in a spin coater for coating.

[0049] In the present invention, the rotation speed of the spin coater is preferably 300 - 3000 r / min. In specific embodiments of the present invention, the rotation speed can be 300 r / min, 500 r / min, 800 r / min, 1000 r / min, 1200 r / min, 1500 r / min, 2000 r / min, 2500 r / min, or 3000 r / min.

[0050] In the present invention, the temperature of the second baking is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the second baking can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0051] Before the second exposure after the second baking, the present invention preferably restores the optical waveguide material obtained after the second baking to room temperature.

[0052] In the present invention, the wavelength of the light used for the second exposure is preferably 365 nm, the light intensity is preferably 20 mW / cm 2 , and the irradiation time is preferably 0.1 - 60 s. In specific embodiments of the present invention, the irradiation time can be 0.1 s, 5 s, 10 s, 20 s, 30 s, 40 s, 50 s, or 60 s.

[0053] In the present invention, the second exposure is carried out under the action of a mask plate.

[0054] In the present invention, the temperature of the third curing is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the third curing can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0055] In the present invention, the temperature of the fourth curing is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the fourth curing can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0056] After forming the core layer, the present invention mixes the raw materials for preparing the upper cladding and coats them on the surface of the core layer for the third baking, third exposure, and fifth curing to form the upper cladding, thereby obtaining the optical waveguide device. In the present invention, the coating preferably includes pouring the raw materials for preparing the upper cladding onto the surface of the core layer and then placing them in a spin coater for coating.

[0057] In the present invention, the rotation speed of the spin coater is preferably 300 - 3000 r / min. In specific embodiments of the present invention, the rotation speed can be 300 r / min, 500 r / min, 800 r / min, 1000 r / min, 1200 r / min, 1500 r / min, 2000 r / min, 2500 r / min, or 3000 r / min.

[0058] In the present invention, the temperature of the third baking is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the third baking can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0059] Before the third exposure after the third baking, in the present invention, it is preferred to restore the optical waveguide material obtained after the third baking to room temperature.

[0060] In the present invention, the wavelength of the light used for the third exposure is preferably 365 nm, the light intensity is preferably 20 mW / cm 2 , and the irradiation time is preferably 0.1 - 60 s. In specific embodiments of the present invention, the irradiation time can be 0.1 s, 5 s, 10 s, 20 s, 30 s, 40 s, 50 s, or 60 s.

[0061] In the present invention, the temperature of the fifth curing is preferably 90 °C, and the time is preferably 10 - 60 min. In specific embodiments of the present invention, the time of the fifth curing can be 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0062] After the fifth curing, in the present invention, it is preferably further subjected to cutting, grinding, and polishing to obtain the optical waveguide device.

[0063] The modified fluorinated phenolic epoxy resin, its preparation method, the photoresist solution, and the optical waveguide device provided by the present invention will be described in detail below with reference to embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0064] Examples 1 - 5 Add 20 g of hexafluorobisphenol A phenolic epoxy resin (softening point 65 - 70 °C) to a 250 mL reaction flask, add 45 mL of ethyl acetate, dissolve with stirring, the volume concentration is 15%, after purging with nitrogen for 1 h, add the alkaline catalyst sodium hydroxide and alkyl chain carboxylic acid, and react at 80 °C for 8 h. After washing with ethanol and acetone, add an appropriate amount of 2 mol / L hydrochloric acid aqueous solution and stir for 2 h, then wash with a large amount of water, and finally dry to obtain hexafluorobisphenol A phenolic epoxy resin with side-chain grafted alkyl chains.

[0065] The differences among Examples 1 to 5 are shown in Table 1 in detail.

[0066] Table 1 Differences among Examples 1 to 5

[0067] Conclusion: It can be seen from the data in the table that after modification with the alkyl-chain carboxylic acid side chain, the epoxy value of the resin decreases, indicating that the carboxyl group of the alkyl acid reacts with the epoxy group to form an ester group. After grafting, the refractive index of the resin decreases significantly, indicating that the method of side-chain grafting can achieve the purpose of adjusting the refractive index of the resin by the reaction ratio of raw materials.

[0068] Figure 1 1H NMR spectra of hexafluorobisphenol A phenolic epoxy resin grafted with different types of alkyl-chain carboxylic acids (where the modification ratio is shown in Table 1). From Figure 1 it can be found that after grafting, the peaks of the epoxy groups in the epoxy resin at chemical shifts 3.32 – 3.35 (2H, m), 2.73 – 2.90 (4H, m) decrease significantly, and the peak of -CH2 in the alkyl chain at 4.06 ppm gradually increases, which is the result of the grafting reaction of the alkyl-chain carboxylic acid with the epoxy group, indicating that carboxylic acid molecules are successfully grafted.

[0069] Examples 6 to 10 Add 20 g of hexafluorobisphenol A phenolic epoxy resin (softening point 65 - 70 °C) to a 250 mL reaction flask, add 45 mL of ethyl acetate, dissolve it with stirring, with a volume concentration of 15%. After purging with nitrogen for 1 h, add the alkaline catalyst sodium hydroxide and fluorinated carboxylic acid, and react at 80 °C for 8 h. After washing with ethanol and acetone, add an appropriate amount of 2 mol / L hydrochloric acid aqueous solution and stir for 2 h, then wash with a large amount of water, and finally dry to obtain hexafluorobisphenol A phenolic epoxy resin with a fluorinated alkyl chain grafted on the side chain.

[0070] The differences among Examples 6 to 10 are shown in Table 1 in detail.

[0071] Table 2 Differences among Examples 6 to 10

[0072] Conclusion: It can be seen from the data in the table that after being modified by fluoroorganic acids with different fluorine contents, the epoxy value of the resin decreases compared with the initial value, indicating that the fluoro carboxylic acid has undergone a ring-opening reaction with the epoxy group to form a covalent bond structure. And the epoxy values obtained with octanoic acids with different fluorine contents are slightly different, indicating that there are differences in the reaction activities of the carboxyl group and the epoxy group. After grafting, the refractive index of the resin decreases significantly with the increase of the fluorine content, indicating that the method of adjusting the fluorine content in the side chain can achieve the purpose of adjusting the refractive index of the resin. Moreover, since the refractive index of the fluoroorganic acid is lower than that of the ordinary organic acid, the refractive index of the modified epoxy resin is lower.

[0073] Examples 11 - 15 The differences from Examples 6 - 10 are shown in Table 3, and the rest are the same as those in Examples 6 - 10.

[0074] Table 3 Differences between Examples 11 - 15 and Examples 6 - 10

[0075] Figure 2 It is the infrared spectrum of perfluoropentanoic acid grafted hexafluorobisphenol A type phenolic epoxy resin with different ratios.

[0076] From Figure 2 it can be found that: after the reaction is completed, a vibration absorption peak of the ester group appears at 1754 cm -1 , indicating that perfluoropentanoic acid has undergone a ring-opening reaction with the epoxy group to form an ester group. The absorption peak of -OH generated at 3442 cm -1 gradually increases with the increase of the modification ratio, and there is still a peak of the remaining epoxy group at 928 cm -1 . At the same time, the characteristic absorption peaks on the benzene ring of hexafluorobisphenol A type phenolic epoxy resin and the C–F absorption peaks at 1126 - 1300 cm -1 are retained at 1606.5 and 1509.1 cm -1 .

[0077] Figure 3 It is the ultraviolet-visible near-infrared spectrum of resins modified by different types of perfluorocarboxylic acids (where the modification ratio is as shown in Table 2).

[0078] By the method of replacing the hydrogen atom in the carbon-hydrogen bond with a fluorine atom, the absorption band is shifted away from the communication bands (1310 and 1550 nm). The results are from Figure 3It can be proved that there are no obvious absorption peaks at wavelengths of 1310 nm and 1550 nm, indicating that the proportion of C-H bonds with large optical absorption in hexafluorobisphenol A phenolic epoxy resin decreases, and the absorption of C-F bonds with low optical absorption is very small instead. This can reduce the absorption loss of the material in the optical communication band, thereby achieving the purpose of reducing optical loss.

[0079] Application Example 1 Fabrication of optical waveguide devices by combining resins modified with different types of alkyl chain carboxylic acids Preparation of the cladding of the optical waveguide material of n-octanoic acid-modified hexafluorobisphenol A phenolic epoxy resin and the core layer material of n-butyric acid-modified hexafluorobisphenol A phenolic epoxy resin: Lower cladding: Add 50 g of n-octanoic acid-modified hexafluorobisphenol A phenolic epoxy resin to a 250 mL round-bottom flask or conical flask, add 20 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator triphenylsulfonium phosphate, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0080] Core layer: Add 50 g of n-butyric acid-modified hexafluorobisphenol A phenolic epoxy resin to a 250 mL round-bottom flask or conical flask, add 20 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator triphenylsulfonium phosphate, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0081] Upper cladding: Add 50 g of n-octanoic acid-modified hexafluorobisphenol A phenolic epoxy resin to a 250 mL round-bottom flask or conical flask, add 17 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator triphenylsulfonium phosphate, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0082] Fabrication process of the lower cladding: Pour the above-mentioned cladding glue solution onto a clean silicon wafer substrate, and then place it in a spin coater with a rotation speed of 2000 rpm for spin coating. After spin coating is completed, transfer it to a hot plate and bake at 90 °C for 10 min.

[0083] After baking, return to room temperature and then expose the entire cladding. The wavelength of the exposure machine is 365 nm, the light intensity is 20 mW / cm 2 , and the irradiation time is 5 s; After exposure, heat it to 90 °C again and bake for 10 min for curing to obtain a lower cladding with a thickness of 10 μm.

[0084] Fabrication process of the core layer: On a clean substrate coated with a lower cladding, pour the core layer adhesive solution and then place it in a spin coater with a rotation speed of 2000 revolutions per minute for spin coating. After spin coating is completed, transfer it to a heating plate and bake it at 90 °C for 10 minutes.

[0085] After baking and returning to room temperature, expose it under the action of a mask plate. Among them, the length and width of the gaps of the mask plate are 10 cm and 50 μm respectively, and the distance between adjacent gaps is 100 μm; the wavelength of the exposure machine is 365 nm, and the light intensity is 20 mW / cm 2 , and the irradiation time is 5 s.

[0086] After exposure is completed, heat it to 90 °C again and bake it for 10 minutes.

[0087] After the drying time ends, let it cool naturally to room temperature with the platform, develop it with a developer for 60 s, and rinse it thoroughly with acetone, isopropyl alcohol, ethanol, and water in sequence, and then dry it.

[0088] Dry the board again, bake it at 90 °C for 10 minutes to obtain a core layer with a thickness of 10 μm.

[0089] Fabrication process of the upper cladding: On a clean substrate coated with the core layer, pour the above-mentioned cladding adhesive solution and then place it in a spin coater with a rotation speed of 2000 revolutions per minute for spin coating. After spin coating is completed, transfer it to a heating plate and bake it at 90 °C for 10 minutes.

[0090] After baking and returning to room temperature, expose the entire cladding. The wavelength of the exposure machine is 365 nm, and the light intensity is 20 mW / cm 2 , and the irradiation time is 5 s; After exposure is completed, heat it to 90 °C again and bake it for 10 minutes for curing to obtain an upper cladding with a thickness of 12 μm.

[0091] After cutting, grinding, and polishing, a waveguide device with a waveguide morphology (size: 10 cm long, end face size: 50 * 50 microns) is obtained.

[0092] A suitable refractive index difference between the core and cladding materials can ensure that the optical waveguide device has lower optical loss. In this application example, although the present invention does not use a fluorine-modified resin, by designing the refractive indices of the core and cladding materials, the light dissipation during waveguide transmission is reduced, thereby reducing the transmission loss of the device to a certain extent; at the same time, the introduction of alkyl chains increases the toughness of the optical waveguide material, making the end face smoother after cutting, grinding, and polishing, reducing the end face coupling loss of the device, and thus reducing the overall device loss of the optical waveguide device.

[0093] By using the Cut-back method, the transmission loss of the optical waveguide device in Application Example 2 is measured to be as low as 0.1 dB / cm.

[0094] Application Example 2 Fabrication of optical waveguide devices by combining different types of perfluorocarboxylic acid-modified resins Preparation of the cladding material of a perfluorooctanoic acid-modified hexafluorobisphenol A phenolic epoxy resin optical waveguide and the core material of a perfluorobutyric acid-modified hexafluorobisphenol A phenolic epoxy resin optical waveguide: Lower cladding: In a 250 mL round-bottom flask or conical flask, add 50 g of perfluorooctanoic acid-modified hexafluorobisphenol A phenolic epoxy resin, add 20 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator sulfonium salt, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0095] Core layer: In a 250 mL round-bottom flask or conical flask, add 50 g of perfluorobutyric acid-modified hexafluorobisphenol A phenolic epoxy resin, add 20 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator sulfonium salt, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0096] Upper cladding: In a 250 mL round-bottom flask or conical flask, add 50 g of perfluorooctanoic acid-modified hexafluorobisphenol A phenolic epoxy resin, add 17 mL of cyclopentanone, dissolve with stirring, add 0.5 g of initiator sulfonium salt, dissolve with stirring, and after filtering through a 0.45 μm filter membrane, a light yellow transparent and homogeneous photoresist solution is obtained.

[0097] The preparation process of the optical waveguide device is the same as that in Application Example 1. The transmission loss of the optical waveguide device in Application Example 2 was measured by the Cut-back method and was as low as 0.05 dB / cm.

[0098] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A modified fluorinated phenolic epoxy resin, characterized in that, It has the structural formula shown in Formula I: Formula I; The R includes -COCH 2x+1 , -COCF 2x+1 or -COCH 2x+1 C y F 2y+1 ; where x = 0 to 15 and y = 0 to 15; n ≥ 1.

2. The modified fluorinated phenolic epoxy resin according to claim 1, wherein n = 3 to 10.

3. The preparation method of the modified fluorinated phenolic epoxy resin according to claim 1 or 2, characterized in that, It includes the following steps: Mix an acid, hexafluorobisphenol A phenolic epoxy resin, a basic catalyst, and a polar organic solvent, and then carry out a graft reaction to obtain the modified fluorinated phenolic epoxy resin; The chemical formula of the acid includes CH 2x+1 COOH, CF 2x+1 COOH or CH 2x+1 C y F 2y+1 COOH.

4. The preparation method according to claim 3, wherein The number average molecular weight of the hexafluorobisphenol A phenolic epoxy resin is 500 to 3000, the degree of polymerization is 3 to 10, the epoxy equivalent is 220 to 500 g / mol, and the softening point is 65 to 70 °C.

5. The preparation method according to claim 3 or 4, characterized in that, The molar ratio of the acid to the amount of epoxy groups in the hexafluorobisphenol A phenolic epoxy resin is 0.1 to 0.8:

1.

6. The preparation method according to claim 3, wherein The basic catalyst includes one or more of NaOH, KOH, LiOH, aniline, benzylamine, NBu4Br, NBu4F, NBu4OH, and NMe4OH.

7. The preparation method according to claim 3 or 6, characterized in that, The molar ratio of the acid to the basic catalyst is 0.5 to 10:

1.

8. A photoresist solution, characterized in that, By mass fraction, it includes the following raw materials: Modified fluorinated phenolic epoxy resin 70 to 75%; Photoinitiator 0.7 to 1%; Polar organic solvent 23 to 28%; The modified fluorinated phenolic epoxy resin is one or more of the modified fluorinated phenolic epoxy resins described in claim 1 or 2 or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in any one of claims 3 to 7.

9. The photoresist solution according to claim 8, wherein, The photoinitiator includes one or more of iodonium salts, triphenylsulfonium phosphate, triphenylsulfonium antimonate, triphenylsulfonium trifluoromethanesulfonate, and triphenylsulfonium methanesulfonate.

10. An optical waveguide device, characterized in that, It includes a cladding layer, a core layer, and a substrate layer stacked in sequence; By mass fraction, the raw materials for preparing the cladding layer include: First modified fluorinated phenolic epoxy resin 70 to 75%; The mass content of the first modified fluorinated phenolic epoxy resin in the cladding layer is greater than the mass content of the third modified fluorinated phenolic epoxy resin in the substrate layer; First photoinitiator 0.7 to 1%; First polar organic solvent 23 to 28%; By mass fraction, the raw materials for preparing the core layer include: Second modified fluorinated phenolic epoxy resin 70 to 75%; Second photoinitiator 0.7 to 1%; Second polar organic solvent 20 to 28%; By mass fraction, the raw materials for preparing the substrate layer include: Third modified fluorinated phenolic epoxy resin 70 to 75%; Third photoinitiator 0.7 to 1%; Third polar organic solvent 20 to 28%; The first modified fluorinated phenolic epoxy resin, the second modified fluorinated phenolic epoxy resin, and the third modified fluorinated phenolic epoxy resin are independently one or more of the modified fluorinated phenolic epoxy resins described in claim 1 or 2 or one or more of the modified fluorinated phenolic epoxy resins prepared by the preparation method described in any one of claims 3 to 7; and the refractive index of the second modified fluorinated phenolic epoxy resin is higher than that of the third modified fluorinated phenolic epoxy resin.

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