Room-temperature long-storage-period photo-thermal dual-curing high-temperature-resistant resin system for fiber prepreg tape and preparation method thereof

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a photo-thermal dual-curing high-temperature-resistant resin system for a fiber prepreg tape and a preparation method of the photo-thermal dual-curing high-temperature-resistant resin system, and the photo-thermal dual-curing high-temperature-resistant resin system comprises a high-temperature-resistant photo-crosslinking epoxy resin component, a thermal initiator component and a photoinitiator component. Under the irradiation of ultraviolet light, the photoinitiator component and the high-temperature-resistant photo-crosslinking epoxy resin component form a primary crosslinking structure, and then the thermal initiator component is completely cured in a heating manner, so that the composite material with excellent performance is obtained. According to the design of the photo-thermal dual-curing resin system, energy consumption processes such as low-temperature storage, high curing temperature and long curing time required by a traditional resin system are omitted, and the problems that in the prior art, the fiber prepreg tape is short in room-temperature storage period, large in refrigeration storage energy consumption, high in cost, long in curing time, high in curing temperature and the like are effectively solved; and the production efficiency is greatly improved, and a new technical path is provided for manufacturing and application of high-performance composite materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and specifically relates to a room temperature long storage period light-heat dual-curing high temperature resistant resin system for fiber prepreg tape and a preparation method thereof. The technology has wide application in preparing high-performance resin-based composite material components. Background Art

[0002] Fiber-reinforced resin-based composite materials are widely used in high-end fields such as aerospace and national defense due to their significant advantages of light weight and high strength. Fiber prepreg tape, that is, a continuous fiber / carbon fiber combination impregnated with resin, is an important intermediate material for manufacturing advanced composite components. Composite materials prepared by the prepreg tape process are favored for their accurate resin content and stable product quality. In particular, fiber prepreg tape composite shells prepared by winding molding technology are indispensable for core components of power systems such as spacecraft, rockets, and missiles. However, the two-component traditional resin system of epoxy resin and amine or anhydride curing agent widely used in practical applications of domestic fiber prepreg tapes currently requires curing at a high temperature of more than 150°C, and the curing process is as long as 10 hours. The system only maintains a shelf life of several hours at room temperature. After the prepreg tape is prepared, curing and cross-linking will occur in a short time, which is difficult to meet the time requirements of impregnation, cutting, stacking and winding when key components are manufactured using fiber prepreg tapes. In addition, the curing process of this system consumes a lot of energy, the molding speed is slow, and it does not have efficient and economical industrial production, which seriously restricts the efficient and energy-saving preparation of key components. In view of this, the challenges facing the current fiber prepreg technology are to improve the room temperature storage stability of fiber prepreg, simplify storage conditions and optimize the molding process. The ideal fiber prepreg resin system should have a long room temperature application period, excellent temperature resistance, low curing energy consumption and convenient material properties to meet the needs of efficient and energy-saving engineering preparation. In response to the above problems, a series of resin systems with a long application period have been developed one after another. For example, the patent "A long storage period low temperature curing epoxy resin-based prepreg and its preparation method" adopts a latent low temperature curing agent and a mixed system of solid and liquid epoxy resins to effectively extend the room temperature application period of the prepreg. The patent "A latent resin composition, prepreg and epoxy composite material" uses organic hydrazides or dicyandiamides as latent curing agents, so that the prepreg can be stored for a long time under refrigerated conditions. In addition, the UV light-curing main resin in the patent "A UV light-curing resin composition and its preparation method and application" is an unsaturated resin with more than two carbon-carbon double bond groups, and the corresponding resin composition exhibits no crystal precipitation, long application period and excellent heat and moisture resistance. However, there are no reports on resin systems with long shelf life for prepreg tapes. Although these studies can provide certain theoretical guidance for the design of resin systems with long shelf life for prepreg tapes, there are still some limitations: first, prepreg tapes containing latent curing agents need to be refrigerated and have a limited shelf life at room temperature; second, the curing temperature is high and the energy consumption is high; finally, the free radical photocuring system may cause a large shrinkage rate of the product, affecting the dimensional stability of the parts, and the strong oxygen inhibition effect of free radical photocuring limits its application to a certain extent.In view of the above problems, the present invention provides a room temperature long storage period light-heat dual-curing high temperature resistant resin system for fiber prepreg and a preparation method thereof, the method selects an adapted photopolymerizable active resin component, a multifunctional epoxy resin, and a room temperature stable photoinitiator and a thermal initiator. The resin system of the present invention has extremely high stability under light-proof storage conditions, and almost no cross-linking polymerization reaction occurs, thereby significantly extending its storage period. When exposed to ultraviolet light, the photoinitiator absorbs photon cations of a specific wavelength, and the high temperature resistant photo-crosslinked epoxy resin prepolymer becomes an excited state through the transfer of intermolecular energy, and pre-crosslinking polymerization occurs, producing a high molecular polymer cured into a three-dimensional network structure in a very short time, and the sample is completely cured by means of the "dark reaction" mechanism of cationic photopolymerization and a relatively short medium and low temperature heat treatment process, solving the problems of short room temperature storage period, difficult refrigerated storage, long curing time and high curing temperature of fiber prepreg in the prior art. The prepared fiber-reinforced resin-based composite material is comparable to the traditional thermal curing system in terms of mechanical properties, high temperature resistance and corrosion resistance. Compared with traditional thermal curing processes, it eliminates energy-consuming processes such as long rotation period and high curing temperature during the curing process, and can save energy by 70-90%, filling the gap in related fields at home and abroad, and providing an effective and practical technical approach for the manufacture and application of high-performance resin-based composite materials. Summary of the invention

[0003] The present invention proposes a light-heat dual-curing high-temperature resistant resin system with a long storage period at room temperature for fiber prepreg tapes and a preparation method thereof. The light-heat dual-curing synergistic cross-linking polymerization system undergoes pre-crosslinking under ultraviolet light, and uses the "dark reaction" mechanism of cationic photopolymerization and a relatively short heat treatment to achieve complete curing of the product, thereby obtaining a composite material with excellent performance. The design of the light-heat dual-curing synergistic cross-linking polymerization system of the present invention effectively solves the problems of the short room temperature storage period, difficult refrigerated storage, long curing time and high curing temperature of fiber prepreg tapes in the prior art. The prepared fiber-reinforced resin-based composite material has mechanical properties, high temperature resistance and corrosion resistance comparable to those of traditional thermal curing systems, the curing cycle is greatly shortened, and the production efficiency is greatly improved.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg tape is composed of 90-95 parts of a high temperature resistant light cross-linking epoxy resin system, 0.5-1 parts of a thermal initiator component and 2-6 parts of a photoinitiator component. A preparation method of a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg tape comprises the following preparation steps:

[0006] 1. Preparation of high temperature resistant photo-crosslinking epoxy resin system: weigh a certain amount of photopolymerizable active resin component and multifunctional high temperature resistant epoxy resin component in a beaker, stir at 40-130°C and 100-500r / min for 20-60min, and cool to room temperature after the two components are evenly mixed to obtain a high temperature resistant photo-crosslinking epoxy resin system;

[0007] 2. Dissolution of thermal initiator: Weigh a certain mass of thermal initiator component and add it to the high temperature resistant light cross-linking epoxy resin system, and stir at a speed of 500r / min for 20-30min until the thermal initiator is fully dissolved, and then move it to a dark room with a yellow light of wavelength ≥570nm for retention;

[0008] 3. Preparation of light-heat dual-curing high-temperature resistant resin system: In a dark room under a yellow light, a certain amount of photoinitiator component is weighed and added to the resin mixture prepared in 2), and stirred at a speed of 500r / min for 20-30min, and then the polymerization system is subjected to ultrasonic dispersion treatment with a pulse cycle of 50s on / 25s off for 20-30min. The setting of this reaction intermittent pulse cycle, on the one hand, effectively improves the dispersion of photoinitiator, photosensitizer and thermal initiator in epoxy resin, and on the other hand, the ultrasonic off period can provide sufficient time for heat in the system to dissipate, which helps to control the reaction temperature and slow down possible overheating reactions; finally, a light-heat dual-curing high-temperature resistant resin system for fiber prepreg is obtained, and the viscosity of the polymerization system at different days is tested using a rotary viscometer.

[0009] The high temperature resistant photo-crosslinkable epoxy resin system in step 1 is compounded by a photopolymerizable active resin component and a multifunctional high temperature resistant epoxy resin component in a mass fraction ratio of 50-90:10-50.

[0010] The photopolymerizable active resin component in step 1 comprises one or more low-viscosity compounds that can rapidly excite active epoxy groups under ultraviolet light conditions to undergo cationic polymerization and curing, has an epoxy value of 0.4-1.0, a viscosity of 50-1500 mPa·s at 40° C., and a structure of at least one of alicyclic epoxy resins, aromatic glycidyl ether epoxy resins, and oxacycloalkane monomers, wherein the structural formulas of the alicyclic epoxy resins, aromatic glycidyl ether epoxy resins, and oxacycloalkane monomers are:

[0011]

[0012] Among them, R1, R2, R3, and R4 are side chains with ether bonds or hydroxyl groups, and the side chain structure does not contain basic groups, and the basic groups include amino groups; the alicyclic epoxy resin can be selected from one or more of 3,4-epoxycyclohexenemethyl-3,4-epoxycyclohexene ester and bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate; the aromatic glycidyl ether epoxy resin can be selected from one or more of bisphenol F epoxy resin and bisphenol A epoxy resin, such as bisphenol A diglycidyl ether epoxy resin; the oxacycloalkane monomer can be selected from one or more of 3,3'-(oxybismethylene)bis(3-ethyl)oxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-oxetanemethanol, and 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane.

[0013] The multifunctional high temperature resistant epoxy resin component in step 1 is: a compound, a polymer and a mixture thereof containing an epoxy group, a rigid skeleton or a bulky substituent, and no basic group in the molecular structure, the number of the epoxy groups is greater than or equal to 3, the rigid skeleton is an aromatic ring, and the bulky substituent refers to a naphthalene ring, an aliphatic ring, a long-chain alkyl, a halogen atom, etc. The introduction of a rigid skeleton or a bulky substituent into the resin molecule to increase steric hindrance to prevent molecular motion can effectively improve the heat resistance of the resin, and the crosslinking density can be effectively improved by increasing the number of epoxy groups or the average functional group of each molecule. The heat resistance of the resin; the multifunctional high temperature resistant epoxy resin has an epoxy value of 0.5-1.0, and can be liquid or solid at room temperature. The structure is preferably at least one of alicyclic glycidyl trifunctional epoxy resin, dicyclopentadiene phenol epoxy resin, and bisphenol A novolac epoxy resin, wherein the structural formulas of alicyclic glycidyl trifunctional epoxy resin, dicyclopentadiene phenol epoxy resin, and bisphenol A novolac epoxy resin are:

[0014]

[0015] Among them, n≥1.

[0016] The thermal initiator in step 2 is a compound that does not contain a basic group, preferably an azo compound, an organic peroxide, such as a mixture of one or more of benzoyl peroxide, tetraphenyl glycol, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, dilauryl peroxide and cumene hydroperoxide.

[0017] The photoinitiator component in step 3 is prepared by compounding a UV initiator and a photosensitizer in a weight ratio of 20-30:1-1.5, wherein the UV initiator is required to have strong UV absorption in a specific band of 350-405 nm, preferably at least one of triaryl hexafluoroantimonate sulfonium salt, triaryl hexafluorophosphate sulfonium salt, 4-octyloxydiphenyl iodonium hexafluoroantimonate, di(4-dodecylphenyl) hexafluoroantimonate iodonium salt, and di(4-isobutylphenyl) hexafluorophosphate iodonium salt. The organic cation of the onium salt photoinitiator is a light-absorbing component, and its structure controls the absorption characteristics of UV light. , photosensitivity, quantum yield, etc.; the anion part includes non-nucleophilic anions such as Sbf6ˉ, Asf6ˉ, Pf6ˉ, Bf4ˉ, etc., which determine the strength of the acid formed in the photolysis process and the initiation efficiency, have a direct impact on the polymerization reaction kinetics, and determine whether the final termination reaction occurs. The reaction activity decreases in the order of Sbf6ˉ, Asf6ˉ, Pf6ˉ, Bf4ˉ; the photosensitizer has an ultraviolet chromophore and a breakable weak bond, preferably one or more of thioxanthone, dibenzophenone, benzoin methyl ether, benzoin isopropyl ether, benzoin butyl ether, and benzil.

[0018] The prepreg tape in step 3 was stored in a light-proof and heat-resistant dual-curing resin system. After 100 days of light-proof storage, the viscosity of the system was tested in accordance with the "GB / T10247-2008 Viscosity Measurement Method". This test aims to explore the performance sustainability of the resin system under storage conditions. Finally, we will classify according to the viscosity change rate (△η / η) of the polymerization system after 100 days according to the following rules, where η is the initial viscosity of the polymerization system and △η is the viscosity change of the polymerization system after 100 days of storage:

[0019] Viscosity change rate after 100 days (△η / η) Storage stability ＜1 Excellent 1-1.5 generally ＞1.5 Poor

[0020] The fibers for the prepreg tape described in step 3 include any one of carbon fiber, glass fiber, aramid fiber, quartz fiber, aromatic polyamide fiber, basalt fiber, and ceramic fiber, or a mixture of two or more thereof, and the K number of the fiber tow is 12-60K.

[0021] The curing process described in step 3 is photothermal synergistic curing, and the specific curing steps are: first, place the beaker containing the photothermal dual-curing high-temperature resistant resin system for the fiber prepreg tape in a vacuum drying oven, and perform a degassing treatment for 10-30 minutes at 30-60°C and a negative pressure of -100KPa; then place it in a vacuum oven with a power of 200-500mw / cm 2, pre-curing is carried out under an ultraviolet LED lamp with an emission wavelength of 365nm, and the vertical distance between the ultraviolet lamp and the polymerization system is maintained at 10-20cm; finally, it is placed in a blast hot oven for heating to achieve thermal curing. After the curing is completed, the oven power is turned off, and when the oven temperature drops below 40°C, the oven door is opened to take out the resin casting obtained by curing.

[0022] The curing process of the photothermal synergistic curing described in step 3 is:

[0023] When the UV pre-curing time is 30-60s, the conditions for thermal curing treatment are: 80℃ / 1h+100℃ / 1h; when the UV pre-curing time is 60-120s, the conditions for thermal curing treatment are: 80℃ / 0.5h+100℃ / 1h; when the UV pre-curing time is 120-300s, the conditions for thermal curing treatment are: 100℃ / 1h.

[0024] Effects of the Invention

[0025] In combination with all the above technical solutions, the advantages and significant effects of the present invention are as follows: (1) The light-heat dual-curing high-temperature resistant resin system for fiber prepreg tapes in the present invention has extremely high stability under the condition of room temperature and light-proof storage, and almost no cross-linking polymerization reaction occurs, which solves the technical problems of short storage period and difficult storage of fiber prepreg tapes in the prior art, and realizes long-term storage of fiber prepreg tapes at room temperature; (2) Multifunctional high-temperature resistant epoxy resin is introduced into the light-heat dual-curing high-temperature resistant resin molecules for fiber prepreg tapes in the present invention. The rigid skeleton or bulky substituents in the molecular structure increase the steric hindrance to prevent molecular movement, which can effectively improve the heat resistance of the resin. By increasing the number of epoxy groups and / or the average functional groups per molecule to increase the cross-linking density, the heat resistance of the resin can be effectively improved. High heat resistance of resin; (3) When the light-heat dual-curing high temperature resistant resin system for fiber prepreg tape in the present invention is exposed to ultraviolet light, the photoinitiator absorbs photons of a specific wavelength, and the high temperature resistant photo-crosslinking epoxy resin prepolymer is rapidly turned into an excited state through the transfer of energy between molecules, and pre-crosslinking polymerization occurs, and a high molecular polymer cured into a three-dimensional network structure is produced in a very short time, and the sample is completely cured by means of the "dark reaction" mechanism of cationic photopolymerization and a relatively short medium and low temperature heat treatment process; (4) Compared with the traditional heat curing process, the light-heat dual-curing process of the present invention omits energy-consuming processes such as high curing temperature and long curing time, and the energy consumption can be saved by 70-90%, and the molded resin polymer has good mechanical properties and high temperature resistance. The present invention is expected to be widely used in the fields of aerospace, automobile industry, sports equipment, wind power generation, chemical textile, machinery manufacturing, construction, pipelines, etc. DETAILED DESCRIPTION

[0026] The technical solution provided by the present invention is described in detail below in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0027] Embodiment 1:

[0028] (1) A high temperature resistant photo-crosslinkable epoxy resin system comprises weighing a photopolymerizable active resin component E51 and a multifunctional high temperature resistant epoxy resin component TDE85 in a mass fraction ratio of 80:20, stirring at a speed of 350 r / min for 30 min at 50° C., adding 1.0 wt % of a thermal initiator component tetraphenyl glycol after the two components are evenly mixed and cooled to room temperature, stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the epoxy resin system, and stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the epoxy resin system. After complete dissolution, move to a dark room environment with a yellow light with a wavelength of more than 570nm, then weigh 2wt.% of a photoinitiator component prepared by compounding triaryl hexafluoroantimonate sulfonium salt and thioxanthone in a weight ratio of 20:1 and add it to the resin system, stir at a speed of 500r / min for 25min, and then ultrasonically treat the polymerization system with a pulse cycle of 50s on / 25s off for 30min to obtain a light-heat dual-curing high-temperature resistant resin system for prepreg tapes, and store the resin system in the dark at room temperature. The light-heat dual-curing high-temperature resistant resin system prepared in this embodiment is tested for viscosity changes after 100 days according to GB / T 10247-2008 and graded according to the effects of the invention. Test results: The viscosity of the resin system does not change significantly after 100 days, and has an excellent room temperature storage period.

[0029] (2) The resin system is cured by a photothermal synergistic curing process. The specific steps are as follows: first, the uniformly mixed photothermal dual-curing high-temperature resistant resin system is placed in a vacuum drying oven and degassed for 20 minutes at 50°C and -100KPa negative pressure; then, the system is placed in a vacuum drying oven at a power of 300mw / cm 2 , pre-cured under an ultraviolet LED lamp with an emission wavelength of 365nm, keeping the vertical distance between the ultraviolet lamp and the polymerization system at 15cm, and the ultraviolet light pre-curing time is 60s; finally, placed in a blast hot oven and heated at a curing system of 80℃ / 1h+100℃ / 1h to achieve thermal curing, and after the curing is completed, the oven power is turned off, and when the oven temperature drops below 40℃, the oven door is opened to take out the epoxy composite material obtained by curing. The temperature resistance of the resin casting is tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting are tested according to "GB / T10247-2008 Viscosity Measurement Method", and the results are recorded in Table 1. Test results: The glass transition temperature of the polymerization system is 183℃, which has high temperature resistance; the tensile strength of the resin casting is 82MPa, and the bending strength is 135MPa, which has good mechanical properties.

[0030] The test results show that the light-heat dual-curing high-temperature resistant resin system for the prepreg tape of this embodiment has a long room temperature applicability period, and the resin system has high temperature resistance. Through the light-heat synergistic curing process, the resin casting obtained exhibits excellent tensile strength and bending strength.

[0031] Comparative Example 1:

[0032] For a high temperature resistant photo-crosslinked epoxy resin system in step (1), the mass fraction ratio of the photopolymerizable active resin component E51 and the multifunctional high temperature resistant epoxy resin component TDE85 is adjusted to 100:0. For the ultraviolet lamp power in step 2), the power is adjusted to 380mw / cm 2 , the UV pre-curing time is adjusted to 100s, the heat curing system is adjusted to 80℃ / 0.5h+100℃ / 1h, and the others are consistent with Example 1. The light-heat dual-curing high temperature resistant resin system prepared in this comparative example is tested for viscosity change after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and graded according to the effect of the invention, the temperature resistance of the resin casting is tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting are tested according to GB / T 2567-2008, and the results are recorded in Table 1. Test results: The viscosity of the resin system has no significant change after 100 days, and it has an excellent room temperature storage period. The glass transition temperature of the resin system is 155℃, and the temperature resistance is poor. The tensile strength of the resin casting is 75MPa and the bending strength is 119MPa.

[0033] The test results show that the light-heat dual-curing high-temperature resistant resin system used in the prepreg tape of this comparative example has a long room temperature application period. In addition, it shows the necessity of a multi-functional high-temperature resistant epoxy resin component to improve the heat resistance of the polymerization system. The heat resistance of the resin system is poor when the multi-functional high-temperature resistant epoxy resin component is lacking.

[0034] Embodiment 2:

[0035] (1) A high temperature resistant photo-crosslinkable epoxy resin system comprises weighing a photopolymerizable active resin component E51 and a dicyclopentadiene phenol epoxy resin in a mass fraction ratio of 85:15, stirring at a speed of 350 r / min for 30 min at 70° C., adding 1.0 wt % of a thermal initiator component tetraphenyl glycol after the two components are evenly mixed and cooled to room temperature, stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the high temperature resistant photo-crosslinkable epoxy resin system, and stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the high temperature resistant photo-crosslinkable epoxy resin system. After complete dissolution, move to a dark room environment with a yellow light with a wavelength of more than 570nm, then weigh 5wt.% of a photoinitiator component prepared by compounding triaryl hexafluoroantimonate sulfonium salt and thioxanthone in a weight ratio of 20:1 and add it to the resin system, stir at a speed of 500r / min for 25min, and then ultrasonically treat the resin system with a pulse cycle of 50s on / 25s off for 30min to obtain a light-heat dual-curing high-temperature resistant resin system for prepreg tapes, and store the resin system in the dark at room temperature. The light-heat dual-curing high-temperature resistant resin system prepared in this embodiment is tested for viscosity changes after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and graded according to the effect of the invention. Test results: The viscosity of the resin system does not change significantly after 100 days, and has an excellent room temperature storage period.

[0036] (2) The resin system is cured by a photothermal synergistic curing process. The specific steps are as follows: first, the uniformly mixed photothermal dual-curing high-temperature resistant resin system is placed in a vacuum drying oven and degassed for 20 minutes at 50°C and -100KPa negative pressure; then, the system is placed in a vacuum drying oven at a power of 300mw / cm 2 , pre-cured under an ultraviolet LED lamp with an emission wavelength of 365nm, keeping the vertical distance between the ultraviolet lamp and the polymerization system at 15cm, and the ultraviolet light pre-curing time is 40s; finally, placed in a blast hot oven and heated at a curing system of 80℃ / 1h+100℃ / 1h to achieve thermal curing. After the curing is completed, turn off the oven power supply, wait for the oven temperature to drop below 40℃, open the oven door and take out the epoxy composite material obtained by curing. The temperature resistance of the resin casting body was tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting body were tested according to GB / T 2567-2008, and the results were recorded in Table 1. Test results: The glass transition temperature of the resin system is 181℃, which has high temperature resistance; the tensile strength of the resin casting body is 80MPa, and the bending strength is 132MPa, which has good mechanical properties.

[0037] The test results show that the light-heat dual-curing high-temperature resistant resin system for the prepreg tape of this embodiment has a long room temperature applicability period, and the resin system has high temperature resistance. Through the light-heat synergistic curing process, the resin casting obtained exhibits excellent tensile strength and bending strength.

[0038] Comparative Example 2:

[0039] The amount of the photoinitiator component added in the high temperature resistant photo-crosslinked epoxy resin system in step (1) is adjusted to 10wt.%, and the light-heat dual-curing high temperature resistant resin system configured in step 1) is stored at room temperature without shielding from light, and the rest is consistent with Example 2. The light-heat dual-curing high temperature resistant resin system prepared in this comparative example is tested for viscosity change after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and graded according to the effect of the invention, the temperature resistance of the resin casting is tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting are tested according to GB / T2567-2008, and the results are recorded in Table 1. Test results: After the resin system is stored under non-shading conditions for 10 days, the viscosity increases significantly and enters the preliminary gelation stage. When stored for 30 days, the resin system has completely lost its fluidity. After further observation for 100 days, the resin system has solidified into a solid state, and the resin system has completely lost its processing applicability as a liquid system. The glass transition temperature of the resin system is 180°C, and it has high temperature resistance; the tensile strength of the resin casting is 81MPa, and the bending strength is 131MPa, and it has good mechanical properties.

[0040] The test results show that the light-heat dual-curing high-temperature resistant resin system for the prepreg tape of this comparative example has high temperature resistance, and the obtained resin casting exhibits excellent tensile strength and flexural strength, but the resin system has a limited storage period in a non-light-proof environment and a significant increase in viscosity, indicating the necessity of storing the light-heat dual-curing high-temperature resistant resin system for the prepreg tape prepared by the present invention away from light.

[0041] Embodiment 3:

[0042] (1) A high temperature resistant photo-crosslinkable epoxy resin system comprises weighing a photopolymerizable active resin component E51 and a multifunctional high temperature resistant epoxy resin component bisphenol A novolac epoxy resin in a mass fraction ratio of 85:15, stirring at a speed of 300 r / min for 30 min at 70° C., adding 1.0 wt % of a thermal initiator component benzoyl peroxide after the two components are evenly mixed and cooled to room temperature, and stirring at a speed of 300 r / min for 20 min until the thermal initiator is fully dissolved in the high temperature resistant photo-crosslinkable epoxy resin system, After the thermal initiator is completely dissolved, it is moved to a dark room environment with a yellow light with a wavelength of more than 570nm, and then 5wt.% of the photoinitiator component prepared by compounding triaryl hexafluoroantimonate sulfonium salt and thioxanthone in a weight ratio of 20:1 is weighed and added to the resin system, and stirred at a speed of 500r / min for 25min, and then the resin system is ultrasonically treated with a pulse cycle of 50s on / 25s off for 30min to obtain a light-heat dual-curing high-temperature resistant resin system for prepreg tape, and the resin system is stored in the dark at room temperature. The light-heat dual-curing high-temperature resistant resin system prepared in this embodiment is tested for viscosity changes after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and is graded according to the invention effect. Test results: The viscosity of the resin system does not change significantly after 100 days, and has an excellent room temperature storage period.

[0043] (2) The resin system is cured by a photothermal synergistic curing process. The specific steps are as follows: first, the uniformly mixed photothermal dual-curing high-temperature resistant resin system is placed in a vacuum drying oven and degassed for 20 minutes at 50°C and -100KPa negative pressure; then, the system is placed in a vacuum drying oven with a power of 350mw / cm 2 , pre-cured under an ultraviolet LED lamp with an emission wavelength of 365nm, keeping the vertical distance between the ultraviolet lamp and the polymerization system at 15cm, and the ultraviolet light pre-curing time is 150s; finally, placed in a blast hot oven and heated at a curing system of 100℃ / 1h to achieve thermal curing. After the curing is completed, turn off the oven power supply, wait for the oven temperature to drop below 40℃, open the oven door and take out the epoxy composite material obtained by curing. The temperature resistance of the resin casting body is tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting body are tested according to GB / T 2567-2008, and the results are recorded in Table 1. Test results: The glass transition temperature of the resin system is 184℃, which has high temperature resistance; the tensile strength of the resin casting body is 83MPa, and the bending strength is 133MPa, which has good mechanical properties.

[0044] The test results show that the light-heat dual-curing high-temperature resistant resin system for the prepreg tape of this embodiment has a long room temperature applicability period, and the resin system has high temperature resistance. Through the light-heat synergistic curing process, the resin casting obtained exhibits excellent tensile strength and bending strength.

[0045] Comparative Example 3:

[0046] Adjust the UV lamp power in step (2) to 400mw / cm 2 , the UV pre-curing time was adjusted to 200s, and the resin-based composite material was obtained without post-heat curing process. The other conditions were the same as those in Example 3. The light-heat dual-curing high-temperature resistant resin system prepared in this comparative example was tested for viscosity change after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and graded according to the effect of the invention. The temperature resistance of the resin casting was tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting were tested according to GB / T 2567-2008, and the results were recorded in Table 1. Test results: The viscosity of the resin system did not change significantly after 100 days, and it had an excellent room temperature storage period. The glass transition temperature of the resin system was 155°C, and the temperature resistance was poor. The tensile strength of the resin casting was 61MPa, and the bending strength was 89MPa.

[0047] The test results show that the light-heat dual-curing high-temperature resistant resin system used in the prepreg tape of this comparative example has a long room temperature applicability period, and the resin system has high temperature resistance. The resin-based composite material lacks a post-heat treatment process during curing, and the tensile strength and interlaminar shear strength of the prepared resin casting are low.

[0048] Embodiment 4:

[0049] (1) A high temperature resistant photo-crosslinkable epoxy resin system comprises weighing a photopolymerizable active resin component E51 and a multifunctional high temperature resistant epoxy resin component TDE85 in a mass fraction ratio of 60:40, stirring at a speed of 350 r / min for 30 min at 50° C., adding 1.0 wt % of a thermal initiator component tetraphenyl glycol after the two components are evenly mixed and cooled to room temperature, stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the epoxy resin system, and stirring at a speed of 500 r / min for 20 min until the thermal initiator is fully dissolved in the epoxy resin system. After complete dissolution, move to a dark room environment with a yellow light with a wavelength of more than 570nm, then weigh 2wt.% of a photoinitiator component prepared by compounding triaryl hexafluoroantimonate sulfonium salt and thioxanthone in a weight ratio of 20:1 and add it to the resin system, stir at a speed of 500r / min for 25min, and then ultrasonically treat the polymerization system with a pulse cycle of 50s on / 25s off for 30min to obtain a light-heat dual-curing high-temperature resistant resin system for prepreg tapes, and store the resin system in the dark at room temperature. The light-heat dual-curing high-temperature resistant resin system prepared in this embodiment is tested for viscosity changes after 100 days according to "GB / T10247-2008 Viscosity Measurement Method" and graded according to the effect of the invention. Test results: The viscosity of the resin system does not change significantly after 100 days, and has an excellent room temperature storage period.

[0050] (2) The resin system is cured by a photothermal synergistic curing process. The specific steps are as follows: first, the uniformly mixed photothermal dual-curing high-temperature resistant resin system is placed in a vacuum drying oven and degassed for 20 minutes at 50°C and -100KPa negative pressure; then, the system is placed in a vacuum drying oven at a power of 300mw / cm 2 , pre-cured under an ultraviolet LED lamp with an emission wavelength of 365nm, keeping the vertical distance between the ultraviolet lamp and the polymerization system at 15cm, and the ultraviolet light pre-curing time is 60s; finally, placed in a blast hot oven and heated at a curing system of 80℃ / 1h+100℃ / 1h to achieve thermal curing. After the curing is completed, turn off the oven power supply, wait for the oven temperature to drop below 40℃, open the oven door and take out the epoxy composite material obtained by curing. The temperature resistance of the resin casting body was tested according to GB / T 40396-2021, and the tensile and bending properties of the resin casting body were tested according to GB / T 2567-2008, and the results were recorded in Table 1. Test results: The glass transition temperature of the polymerization system is 183℃, which has high temperature resistance; the tensile strength of the resin casting body is 82MPa, and the bending strength is 135MPa, which has good mechanical properties.

[0051] The test results show that the light-heat dual-curing high-temperature resistant resin system for the prepreg tape of this embodiment has a long room temperature applicability period, and the resin system has high temperature resistance. Through the light-heat synergistic curing process, the resin casting obtained exhibits excellent tensile strength and bending strength.

[0052] Comparative Example 4:

[0053] (1) Bisphenol A glycidyl ether epoxy resin E51 and multifunctional high temperature resistant epoxy resin component TDE85 were stirred at a mass fraction ratio of 60:40 at 50°C at a speed of 350r / min for 30min. After the two components were evenly mixed and cooled to room temperature, 30.0wt% of amine curing agent (dimethylthiotoluenediamine) was added and stirred at a speed of 500r / min for 20min until the curing agent was fully dissolved in the epoxy resin system. The resin system was stored at room temperature in the dark. The viscosity change of the resin system prepared in this embodiment was tested according to "GB / T10247-2008 Viscosity Measurement Method" after 100 days and the grades were divided according to the invention effect. Test results: The viscosity of the resin system increased significantly within 20 days, and the room temperature storage period was short.

[0054] (2) Place the mixed resin system in a vacuum drying oven and perform a degassing treatment for 20 minutes at 50°C and -100KPa negative pressure; then place it in a blast hot oven and heat it at a curing system of 100°C / 1h+150°C / 3h+180°C / 6h to achieve thermal curing. After the curing is completed, turn off the oven power supply, wait for the oven temperature to drop below 40°C, open the oven door and take out the epoxy composite material obtained by curing. Test the temperature resistance of the resin casting according to GB / T 40396-2021, and test the tensile and bending properties of the resin casting according to GB / T 2567-2008, and record the results in Table 1. Test results: The glass transition temperature of the resin system is 188°C, which has high temperature resistance; the tensile strength of the resin casting is 86MPa, and the bending strength is 137MPa, which has good mechanical properties.

[0055] The test results show that the prepreg tape of this comparative example has a shorter room temperature application period using a traditional thermosetting resin system, and Example 4 has comparable temperature resistance and mechanical properties to those of the comparative example.

[0056] In the example, a fiber prepreg tape is tested for viscosity change after 100 days using a room temperature long storage period light-heat dual-curing high temperature resistant resin system according to GB / T10247-2008 Viscosity Measurement Method and graded according to the invention effect. The temperature resistance of the resin casting is tested according to GB / T40396-2021; the tensile and bending properties of the resin casting are tested according to GB / T 2567-2008. The above example data are collected, and the test results are shown in Table 1.

[0057] Table 1 Performance evaluation results of each instance

[0058]

[0059] As can be seen from Table 1, the fiber prepreg tapes prepared in Examples 1 to 4 have a long room temperature storage period light-heat dual-curing high temperature resistant resin system, and have a long room temperature applicability period, and the resin system has high temperature resistance. The resin-based composite material obtained by the light-heat dual-curing process exhibits excellent tensile strength and flexural strength.

Claims

1. A room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg tape, characterized in that: The resin system consists of 90-95 parts of a high temperature resistant photo-crosslinking epoxy resin system, 0.5-1 parts of a thermal initiator component and 2-6 parts of a photoinitiator component.

2. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 1, characterized in that: The method comprises the following preparation steps: (1) Preparing a high temperature resistant photo-crosslinkable epoxy resin system: Weigh a certain amount of a photopolymerizable active resin component and a multifunctional high temperature resistant epoxy resin component in a beaker, stir at 40-130° C. and a speed of 100-500 r / min for 20-60 min, and cool to room temperature after the two components are evenly mixed to obtain a high temperature resistant photo-crosslinkable epoxy resin system; (2) Dissolution of thermal initiator: Weigh a certain amount of thermal initiator component and add it to the high temperature resistant photo-crosslinkable epoxy resin system, and stir at a speed of 500 r / min for 20-30 min until the thermal initiator is fully dissolved, and then move it to a dark room under a yellow light with a wavelength of ≥570 nm for retention; (3) Preparation of a light-heat dual-curing high-temperature resistant resin system: In a dark room under a yellow light lamp, a certain amount of photoinitiator component is weighed and added to the resin mixture prepared in 2), and stirred at a speed of 500 r / min for 20-30 min. Then, the polymerization system is subjected to ultrasonic dispersion treatment with a pulse cycle of 50 s on / 25 s off for 20-30 min to obtain a light-heat dual-curing high-temperature resistant resin system for fiber prepreg tapes.

3. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The high temperature resistant photo-crosslinking epoxy resin system is compounded by a photopolymerizable active resin component and a multifunctional high temperature resistant epoxy resin component in a mass fraction ratio of 50-90:10-50.

4. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The photopolymerizable active resin component comprises one or more low-viscosity compounds that can rapidly excite active epoxy groups under ultraviolet light conditions to undergo cationic polymerization and curing, has an epoxy value of 0.4-1.0, a viscosity of 50-1500 mPa·s at 40° C., and a structure of at least one of alicyclic epoxy resins, aromatic glycidyl ether epoxy resins, and oxacycloalkane monomers, wherein the structural formulas of the alicyclic epoxy resins, aromatic glycidyl ether epoxy resins, and oxacycloalkane monomers are: Among them, R1, R2, R3, and R4 are side chains with ether bonds or hydroxyl groups, and the side chain structure does not contain basic groups, and the basic groups include amino groups; the alicyclic epoxy resin can be selected from one or more of 3,4-epoxycyclohexenemethyl-3,4-epoxycyclohexene ester and bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate; the aromatic glycidyl ether epoxy resin can be selected from one or more of bisphenol F epoxy resin and bisphenol A epoxy resin, such as bisphenol A diglycidyl ether epoxy resin; the oxacycloalkane monomer can be selected from one or more of 3,3'-(oxybismethylene)bis(3-ethyl)oxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-oxetanemethanol, and 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane.

5. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The multifunctional high temperature resistant epoxy resin component is: a compound, a polymer and a mixture thereof containing epoxy groups, a rigid skeleton or a bulky substituent, and no basic groups in the molecular structure, the number of the epoxy groups is greater than or equal to 3, the rigid skeleton is an aromatic ring, the bulky substituent refers to a naphthalene ring, an aliphatic ring, a long chain alkyl, a halogen atom, etc., the epoxy value is 0.5-1.0, and it can be liquid or solid at room temperature. The structure is preferably at least one of alicyclic glycidyl trifunctional epoxy resin, dicyclopentadiene phenol epoxy resin, and bisphenol A novolac epoxy resin, wherein the structural formulas of alicyclic glycidyl trifunctional epoxy resin, dicyclopentadiene phenol epoxy resin, and bisphenol A novolac epoxy resin are respectively: Among them, n≥1.

6. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The thermal initiator is a compound without a basic group, preferably an azo compound, an organic peroxide, such as benzoyl peroxide, tetraphenyl glycol, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, dilauryl peroxide and cumene hydroperoxide, or a combination thereof.

7. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The photoinitiator component is prepared by compounding an ultraviolet light initiator and a photosensitizer in a weight ratio of 20-30:1-1.5, wherein the ultraviolet light initiator is required to have strong ultraviolet light absorption in a specific band of 350-405 nm, and is preferably at least one of triaryl sulfonium hexafluoroantimonate, triaryl sulfonium hexafluorophosphate, 4-octyloxydiphenyl iodonium hexafluoroantimonate, di(4-dodecylphenyl) iodonium hexafluoroantimonate, and di(4-isobutylphenyl) iodonium hexafluorophosphate; the photosensitizer has an ultraviolet chromophore and a breakable weak bond, and is preferably one or more of thioxanthone, benzophenone, benzoin methyl ether, benzoin isopropyl ether, benzoin butyl ether, and benzil.

8. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The fibers for the prepreg tape include any one of carbon fiber, glass fiber, aramid fiber, quartz fiber, aromatic polyamide fiber, basalt fiber, ceramic fiber, or a mixture of two or more thereof, and the K number of the fiber bundle is 12-60K.

9. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The curing process is photothermal synergistic curing. The specific curing steps are as follows: first, place the beaker containing the fiber prepreg with a photothermal dual-curing high-temperature resistant resin system in a vacuum drying oven and perform a degassing treatment for 10-30 minutes at 30-60°C and a negative pressure of -100KPa; then place it in a vacuum oven with a power of 200-500mw / cm 2 , pre-curing is carried out under an ultraviolet LED lamp with an emission wavelength of 365nm, and the vertical distance between the ultraviolet lamp and the polymerization system is maintained at 10-20cm; finally, it is placed in a blast hot oven for heating to achieve thermal curing. After the curing is completed, the oven power is turned off, and when the oven temperature drops below 40°C, the oven door is opened to take out the resin casting obtained by curing.

10. The method for preparing a room temperature long storage period light-heat dual curing high temperature resistant resin system for fiber prepreg according to claim 2, characterized in that: The curing process of the photothermal synergistic curing is: When the UV pre-curing time is 30-60s, the conditions for thermal curing treatment are: 80℃ / 1h+100℃ / 1h; when the UV pre-curing time is 60-120s, the conditions for thermal curing treatment are: 80℃ / 0.5h+100℃ / 1h; when the UV pre-curing time is 120-300s, the conditions for thermal curing treatment are: 100℃ / 1h.

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