A high-temperature-resistant resin system for dry-winding prepreg and a preparation method thereof

Abstract

The application provides a high-temperature-resistant resin system for dry winding prepreg and a preparation method. Dicyclopentadiene phenolic epoxy and multi-function naphthalene ring epoxy resin are selected as main body resins, and various components are used to adjust the viscosity and tackiness of the system. A composite curing agent is selected to adjust the rheological process and curing activity of the system. An organic / inorganic hybrid latent polyphosphazene curing agent is used to cooperatively improve the high-temperature resistance and mechanical properties of the system. A metal phthalocyanine high-temperature-resistant modification component is used to further adjust the high-temperature resistance and rheological properties. By adjusting the chemical structures and proportions of the resin matrix, the composite curing agent and the high-temperature-resistant modification component, a resin system with excellent high-temperature resistance and "smart tack" characteristics is obtained, and the prepreg prepared has the "smart tack" characteristics of dry winding and winding. The application fills the blank of the high-temperature-resistant resin material system for dry winding, and will strongly promote the development and application of dry winding in the lightweight parts of the aerospace field.

Description

Technical Field

[0001] This invention belongs to the field of resin-based composite material technology, and mainly relates to a high-temperature resistant resin system and preparation method for dry-wound prepreg tape. Background Technology

[0002] Carbon fiber composite wound rotating parts are widely used in the aerospace industry for lightweight components due to their lightweight and high strength. Fiber winding is mainly divided into wet winding and dry winding. Traditional winding processes primarily use resin-impregnated wet winding, which typically employs low to medium viscosity resin systems. During winding, it is susceptible to resin flow and slippage, making it difficult to control resin content and finished product quality. Considering the harsh application environment in the aerospace field, it is necessary to further improve the high-temperature resistance of the resin system, which inevitably leads to an increase in resin viscosity, rendering wet winding unsuitable. Dry winding is a new process that separates impregnation and winding, allowing for precise control of the resin content in the wound part (within ±2% error) and further increasing the fiber volume fraction, overcoming the performance bottleneck of composite materials. Simultaneously, high-viscosity resin systems are suitable for dry prepreg preparation, facilitating the application of higher-performance, high-temperature resistant resins in wound products to meet the high-temperature resistance requirements of the aerospace industry. However, high-temperature resistant resins often have excessively high viscosity, making it difficult to perfectly coat the fiber surface during impregnation and causing adhesion between fibers during yarn unwinding. Therefore, the design of high-temperature resistant resin systems for dry-wound prepreg tapes not only needs to focus on the high-temperature resistant molecular structure design of the material system, but also on the matching of material properties with process parameters.

[0003] Currently, Chinese patent CN103608378B discloses a rheologically tunable resin and its preparation method, which uses a mixture of solid and liquid multi-component epoxy to adjust the rheological properties of the resin system, but it is only applicable to the room temperature and medium temperature range. Chinese patent CN113733400A discloses a dry winding prepreg yarn preparation equipment and its preparation process, which uses the β-ray method to detect and precisely control the glue content online, but the solvent method preparation process used cannot avoid solvent residue in the resin system, resulting in significantly lower performance of the composite material after curing. Chinese patent CN107901447A discloses a prepreg tape preheating molding carbon fiber composite rotary part winding process, which combines the prepreg tape slitting preparation method with the winding mandrel preheating process to solve the problems of precise temperature control and molding die heating in dry winding technology. However, the slitting process inevitably damages the fiber, leading to a decrease in the performance of the part, and the mandrel preheating cannot adapt to the uniform heating under multi-layer winding, which limits its practical application. Currently, there are no publicly available patents for high-temperature resistant resin material systems used in dry-wound prepreg tape. Although the aforementioned patents can provide some guidance for the design and development of high-temperature resistant resin material systems for dry-wound prepreg tape and the optimization of prepreg tape preparation processes, they cannot realize the application of high-temperature resistant resin systems in dry winding. The synergistic matching problem of "material-process" in the design of high-temperature resistant resins for dry winding remains an unresolved issue. Furthermore, the lack of evaluation methods for the "intelligent adhesion" characteristics of dry-wound prepreg tape hinders the development and iteration of resin systems for dry-wound prepreg tape. To address this problem, this invention provides a high-temperature resistant resin system and preparation method for dry-wound prepreg tape. Based on the structure-property relationship theory, the selection of the main resin and curing agent is guided by a designed and prepared latent polyphosphazene curing agent, which synergistically enhances the curing activity and mechanical properties of the resin system. Furthermore, a high-temperature resistant metal phthalocyanine modifier is used to further regulate the high-temperature resistance and process rheology of the resin system. This constructs a complete design method for a high-temperature resistant resin system for dry-wound prepreg tape. A reasonable evaluation method is also developed based on the prepreg tape preparation process requirements and dry-wound application needs, facilitating the subsequent selection and development of other resin systems. This fills the gap in the design of high-temperature resistant resin materials for dry-wound tape and provides a matrix material for the development and application of dry-wound technology in lightweight components in the aerospace field. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature resistant resin system and preparation method for dry-wound prepreg tape. The resin matrix is ​​mainly composed of dicyclopentadiene-type phenolic epoxy and multifunctional naphthalene ring epoxy resins, supplemented with various component epoxy resins to adjust the viscosity and tackiness of the system. A composite curing agent is selected to adjust the viscosity and curing activity of the resin system. An organic / inorganic hybrid latent polyphosphazene is used as a secondary curing agent component to adjust the high-temperature resistance and room temperature latency of the system. A terminal amino metal phthalocyanine is used as a high-temperature resistant modifying component. The application of the resin system in the preparation of prepreg tape is realized by dynamically matching the material-process parameters. Dicyclopentadiene-type phenolic epoxy and multifunctional naphthalene-based epoxy resins were selected as the main resins to ensure basic performance. Various component resins, including glycidyl amine, hydantoin, and silicone-modified epoxy resins, were used to adjust the viscosity and tackiness of the resin matrix. A composite curing agent was selected to ensure the mechanical properties of the cured resin. Low-viscosity, high-temperature resistant aromatic amines and alicyclic amines were used as the main components to ensure the high-temperature resistance of the cured system. The secondary curing agent was alicyclic or aromatic diisocyanate-terminated latent polyphosphazene with good room-temperature latency. Terminal amino metal phthalocyanine was selected as a high-temperature resistant modifying component to further optimize the high-temperature resistance and processing performance of the resin system. Through the formulation of the above components and the dynamic optimization and matching of the preparation process parameters, the precise design and successful preparation of a high-temperature resistant resin system for dry-wound prepreg tape were achieved.

[0005] The solution adopted by this invention to solve the technical problem is as follows:

[0006] A high-temperature resistant resin system for dry-wound prepreg tape is composed of a resin matrix, a composite curing agent, and a high-temperature resistant modifying component.

[0007] Preferably, the high-temperature resistant resin system for the dry-wound prepreg tape is formulated as follows: 100 parts resin matrix, 10-50 parts composite curing agent, and 1-15 parts high-temperature resistant modifying component.

[0008] Optionally, the resin matrix is ​​composed of a main resin and component resins, wherein the main resin comprises 60-100 parts and the component resins comprise 10-50 parts. The main resin is a compound of one or more of dicyclopentadiene-type phenolic epoxy resin and multifunctional naphthalene ring epoxy resin, and the component resin is a compound of one or more of glycidylamine-type, hydantoin-type, and organosilicon-modified epoxy resins. The dicyclopentadiene-type phenolic epoxy resin is a novel special epoxy resin obtained by polycondensation and epoxidation of dicyclopentadiene and phenol and their derivatives. It can impart properties such as high adhesion and high flowability to the resin while maintaining the high-temperature resistance of phenolic resin, helping to adjust the viscosity and tack of the resin system and making the pre-impregnation process more thorough. The multifunctional naphthalene ring epoxy resin contains a naphthalene ring and two or more epoxy groups in its molecular structure, exhibiting high thermal stability and high-temperature mechanical properties, further improving the overall high-temperature resistance of the resin matrix. The glycidylamine-type epoxy resin is a compound of common... Compared to glycidyl ether epoxy resins, the replacement of carbon-oxygen bonds with carbon-nitrogen bonds significantly improves their high-temperature resistance. Hydantoin epoxy resin is a novel special epoxy resin with hydantoin heterocyclic rings obtained by glycidylation of hydantoin or its derivatives. The hydantoin heterocyclic structure endows it with excellent electrical insulation, high-temperature resistance, weather resistance, and wear resistance. Organosilicon-modified epoxy resin is a special epoxy resin with a flexible silicon-oxygen structure obtained by physically blending or chemically grafting epoxy resin with siloxane structure. This not only improves the resin's high-temperature resistance, weather resistance, and flexibility, but also reduces the internal stress of the system. Preferably, poly[(phenyl glycidyl ether)-co-dicyclopentadiene] (epoxy equivalent of 270-300 g / eq) and naphthyldiamine tetraepoxy (epoxy equivalent of 120-170 g / eq) with excellent high-temperature resistance are used as the main resins, and tetraglycidyl diaminodiphenylmethane (epoxy equivalent of 110-125 g / eq), 5,5'-dimethyl-1,3-di(epoxyethylene methyl)imidazolidine-2,4-dione (epoxy equivalent of 153-154 g / eq), 5,5'-dimethyl-1,3-di(2-epoxyethylene-ethoxymethyl)imidazolidine-2,4-dione (epoxy equivalent of 135-143 g / eq), glycidyl etheroxypropylcyclotetrasiloxane (epoxy equivalent of 160-190 g / eq) and other components are used as component resins to form the resin matrix.

[0009] Optionally, the composite curing agent is composed of a main curing agent component and a latent polyphosphazene curing agent. The main curing agent component is a compound of one or more high-temperature resistant aromatic amines, alicyclic amines, etc. The aromatic amine curing agents include: diethyltoluenediamine, dimethylthiotoluenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, etc. The alicyclic amine curing agents include: 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, isophoronediamine, etc. Preferably, 4,4'-diaminodiphenylmethane, diethyltoluenediamine, dimethylthiotoluenediamine, and 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane are selected as the main curing agent components and mixed with latent polyphosphazene curing agents to obtain a composite curing agent with excellent high-temperature resistance. The high-temperature resistance is further improved by increasing the content of heat-resistant macrocyclic structures in the system. At the same time, the selected curing agents such as dimethylthiotoluenediamine have good latency and excellent rheological properties, which can further optimize the dry processability of the resin system and improve the processing convenience and storage stability of the resin system for prepreg tape preparation.

[0010] Optionally, the latent polyphosphazene curing agent is an organic / inorganic hybrid polymer with phosphazene ring and aromatic ring structure. The raw materials for synthesis are selected from A2 monomer and B6 monomer. The terminal amine curing agent with hyperbranched structure and size of 200-800nm ​​is prepared by solution polymerization. On this basis, the room temperature latency is controlled by end capping with alicyclic or aromatic diisocyanate. A2 monomers include: 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,3'-diamino-4,4'-dihydroxydiphenyl sulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, etc.; B6 monomers include: hexafluorocyclotriphosphazene, hexachlorocyclotriphosphazene, hexa-p-carboxyphenoxycyclotriphosphazene, hexa(4-carboxyphenoxy)cyclotriphosphazene, hexa(allyloxy)cyclotriphosphazene, etc.; alicyclic or aromatic diisocyanate end-capping agents include: toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, etc. Preferably, hexachlorocyclotriphosphazene and 4,4'-diaminodiphenyl sulfone are used as reactants, triethanolamine as an acid-binding agent, and acetonitrile as a solvent to prepare hyperbranched polyphosphazene curing agents through solution polymerization. The terminal amine-group polyphosphazene is mixed with isophorone diamine diisocyanate to seal the active amine groups of the curing agent at room temperature, allowing it to be re-unsealed only after reaching a specific temperature, thus giving the polyphosphazene curing agent good latency. The hyperbranched structure increases toughness by increasing the free volume of the material, while the abundant terminal groups can form chemical bonds with the resin matrix, strengthening the mechanical properties of the material. Furthermore, the introduction of phosphazene rings and benzene rings helps to improve the high-temperature resistance of the system, achieving simultaneous enhancement of the high-temperature resistance and mechanical properties of the resin matrix by the high-temperature resistant components.

[0011] Optionally, the high-temperature resistant modified component is a terminal amino metal phthalocyanine, specifically one of cobalt, copper, iron, or zinc phthalocyanine with a planar macrocyclic structure. Nitrophthaloyl derivatives, urea, metal chlorides, and catalysts are selected as reaction raw materials. A terminal nitrophthalocyanine intermediate is prepared by microwave heating, and then a reducing agent is used to convert the nitro group to an amino group, yielding a metal phthalocyanine with a terminal amino structure. The selection of raw material monomers should meet the synthesis requirements of the phthalocyanine structure. Nitroamides, diacids, or anhydrides should be able to form a planar macrocyclic conjugated structure composed of four isoindole units with urea under certain conditions. Nitrophthaloyl derivatives include: 4-nitrophthalamide, 4-nitrophthalic acid, 4-nitrophthalonitrile, etc.; metal chlorides include: cobalt chloride hexahydrate, copper chloride dihydrate, ferrous chloride tetrahydrate, zinc acetate dihydrate, etc.; catalysts include: ammonium molybdate, 1,8-diazahexacyclic [5,4,0]undecene-7, sodium-molybdenum composite catalysts, etc. Preferably, tetranitrophthalocyanine copper is prepared by mixing 4-nitrophthalamide, urea, and copper chloride dihydrate, using ammonium molybdate as a catalyst, and then heating the mixture evenly with microwave. The product is washed and then reacted with sodium sulfide nonahydrate in DMF under heat. After washing and drying, tetraaminophthalocyanine copper is obtained. The macrocyclic structure of phthalocyanine can further enhance the high-temperature resistance of the resin system, and the multiple amino reaction sites can participate in the formation of the epoxy crosslinking network, further regulating and improving the rigid structure of the crosslinking network, thereby improving the high-temperature resistance of the resin system. Furthermore, the terminal amino groups improve the compatibility of the epoxy resin system and also have an auxiliary regulatory effect on the curing activity and rheological properties of the resin system.

[0012] Preferably, the composite curing agent is a mixture of aromatic amine, alicyclic amine and latent polyphosphazene, wherein the aromatic amine is 100 parts, the alicyclic amine is 5-20 parts, and the polyphosphazene is 10-30 parts.

[0013] The method for preparing a high-temperature resistant resin system for dry-wound prepreg tape is characterized by the following preparation steps:

[0014] 1) Preparation process of resin matrix: The resin matrix is ​​made by mixing the main resin with a variety of component resins, wherein the main resin is 60-100 parts and the component resins are 10-50 parts. The mixture is heated to 80-150℃ and mechanically stirred at a speed of 300-600 rpm for 5-15 minutes until the system is homogeneous and transparent, thus obtaining a resin matrix with suitable viscosity and adhesion.

[0015] 2) Preparation process of latent polyphosphazene curing agent: Tetrahydrofuran, N,N'-dimethylformamide or acetonitrile are selected as solvents. A2 monomer and B6 monomer are reacted at 40-80℃ for 4-8 hours at a mass ratio of 2.5-2.8:1-1.2. The precipitate is separated, washed and dried. Then the product is reacted with diisocyanate end-capping agent in dimethyl sulfoxide or N,N'-dimethylformamide at 60-80℃ for 0.5-3 hours to end-cap, and the latent polyphosphazene curing agent can be obtained.

[0016] 3) Preparation process of composite curing agent: The main curing agent components are high-temperature resistant aromatic amines and alicyclic amines with room temperature viscosity of less than 1000 mPa·s, and latent polyphosphazene curing agent is added. The above three components are mixed and prepared in a mass ratio of 100:5-20:1-30, heated to 80-180℃ and mechanically stirred for 10-30 minutes to obtain a uniform and stable composite curing agent.

[0017] 4) Preparation process of high temperature resistant modified component: Nitrophthaloyl derivatives, urea, metal chlorides and catalysts are selected as reaction raw materials. The raw materials are mixed evenly according to the stoichiometric ratio and reacted at 160-200℃ for 1-3h. After washing the obtained nitrophthalocyanine intermediate, a reducing agent is added and reacted for 1-3h. The product is washed and purified to obtain the high temperature resistant modified component of terminal amino metal phthalocyanine.

[0018] 5) Preparation process of high temperature resistant resin system: The resin matrix obtained in step 1), the composite curing agent obtained in step 3), and the high temperature resistant modified component obtained in step 4) are mixed at a mass ratio of 100:10-50:1-15, and heated and stirred at 60-120℃ for 10-15 minutes to obtain a resin system for dry winding with excellent high temperature resistance.

[0019] The high-temperature resistant resin system and preparation method for dry-wound prepreg tape are characterized in that the obtained high-temperature resistant resin system is processed through a certain preparation process to obtain dry-wound prepreg tape. The "smart adhesion" characteristics of the prepared resin system and prepreg tape are evaluated by the following evaluation methods, mainly as follows:

[0020] 1) Preparation of "Smart Adhesion" Characteristics Test: The high-temperature resistant resin system must be compatible with the prepreg tape preparation process. While maintaining a wide range of adjustable process parameters, the resin viscosity should be low during high-temperature impregnation to achieve good impregnation between the resin and the fiber, and the resin viscosity should be high during low-temperature setting to achieve bundled setting of the prepreg tape. This test is performed using the rotational viscosity method in GB / T12007.4-89. The viscosity should be higher than 90000 mPa·s at 25℃ and lower than 3000 mPa·s at 80℃.

[0021] 2) Yarn "Smart Adhesion" Characteristic Test: The prepreg tape made with the high-temperature resistant resin system needs to be wound and stored according to a certain linear shape. Therefore, during use, it is necessary to achieve continuous and stable yarn unwinding under a certain tension without damaging the prepreg tape. This test adopts the parallel traction test method, and the specific operation is as follows: Apply a tension of 10-50N so that the yarn unwinding direction is tangent to the roll body, such as... Figure 1 As shown in (a), the prepreg tape is classified and evaluated based on its peeling state on the roll material. Evaluation indicators are determined according to the adhesion during yarn unwinding, the amount of resin overflow from the prepreg tape surface, the amount of fuzzing, and the edge regularity. Figure 1 As shown in (bd), the evaluation is based on the adhesion of the prepreg tape during yarn feeding, the amount of resin overflow on the surface, the amount of fuzzing, and the edge regularity.

[0022] 3) "Smart Adhesion" Test for Winding Characteristics: The prepreg tape made from the high-temperature resistant resin system needs to meet the requirements of dry winding molding applications. Therefore, it is necessary to test the slippage of the prepreg tape during the winding process using a variable angle and variable tension winding method. This test uses the variable angle and variable tension winding test method, applying a tension of 10-100N to spirally wind the prepreg tape on the mandrel surface, and observing whether slippage occurs during variable angle winding at 15-90 degrees. The possible slippage situations of the prepreg tape are as follows: Figure 2 As shown, the evaluation is based on the slippage of the prepreg tape on the mandrel.

[0023] The high-temperature resistant resin system and preparation method for dry-wound prepreg tape, when evaluating the "smart adhesion" characteristics of the prepared resin system and prepreg tape, comprehensively considers various indicators in the "smart adhesion" characteristic test, and classifies the "smart adhesion" characteristics of the prepreg tape into five levels, with the evaluation criteria as follows:

[0024] Table 1 Evaluation Criteria for "Smart Adhesion" Grade of Prepreg Tape

[0025] Excellent Non-adhesive Very few none Completely regular good Slight adhesion Very few less Basic regularity generally Slight adhesion Partial overflow less Partially incomplete Poor Severe adhesion Excessive overflow More Partially incomplete Range Severe adhesion Excessive overflow a lot of Frequently damaged

[0026] Invention Effects

[0027] (1) By selecting dicyclopentadiene-type phenolic epoxy and multifunctional naphthalene ring epoxy resin as the main resins, and selecting a variety of component resins with excellent high temperature resistance and mechanical properties to participate in the regulation of the rheological properties and high temperature resistance of the resin matrix, it is ensured that while improving the high temperature resistance of the resin system, the physical properties of the resin matrix are dynamically matched with the requirements of the dry process.

[0028] (2) In the design of organic molecular structure, an inorganic phosphazene ring structure is introduced, an organic / inorganic hybrid latent polyphosphazene curing agent is designed and prepared, and it is used as a secondary curing agent to be mixed with high temperature resistant low viscosity aromatic amine and alicyclic amine. Then, a metal phthalocyanine high temperature resistant modification component is introduced to participate in the process of epoxy crosslinking network formation, and the high temperature resistance and mechanical properties of the resin system are synergistically regulated.

[0029] (3) Based on the actual process requirements of prepreg preparation and application, and taking into account the synergistic matching of "material-process", an evaluation method for the "intelligent adhesion" characteristics of dry winding prepreg was established around the key indicators of "intelligent adhesion" test, which has guiding significance for the development and iteration of resin system for prepreg. Attached Figure Description

[0030] Figure 1 Schematic diagram of evaluation methods and index classification for prepreg tape

[0031] Figure 2 A schematic diagram illustrating the potential slippage trend that may occur during dry winding of prepreg tape.

[0032] Figure 3 Schematic diagram of viscosity-temperature relationship of resin systems for dry and wet winding. Detailed implementation method:

[0033] This invention provides a high-temperature resistant resin system and preparation method for dry-wound prepreg tape. The invention is further illustrated below by examples and comparative examples, but the invention is not limited to the following examples; the invention can be interpreted in other broader aspects and is not limited to these examples.

[0034] Example 1 of high temperature resistance performance

[0035] Hexachlorocyclotriphosphazene and 4,4'-diaminodiphenyl sulfone, with triethanolamine as an acid-binding agent and acetonitrile as a solvent, were solution polymerized under a N2 atmosphere for 6 hours. After washing the product, isophorone diisocyanate was added and reacted for 2 hours to obtain a latent polyphosphazene curing agent. Diethyltoluene diamine, 4,4'-diaminodicyclohexylmethane, and polyphosphazene were mixed in an optimal ratio of 40:7.5:6 and added to a beaker with mechanical stirring. The mixture was heated to 80℃, stirred at 600 r / min for 45 minutes to obtain a composite curing agent. 4-Nitrophthalamide, urea, and copper chloride dihydrate were mixed and heated in microwave for 1.5 hours with ammonium molybdate as a catalyst. After washing the product, it was heated and stirred with sodium sulfide nonahydrate in DMF for 2.5 hours. The high-temperature resistant modified component of tetraaminophthalocyanine copper was obtained by net drying. Then, poly[(phenyl glycidyl ether)-co-dicyclopentadiene], 1,5-naphthyldiamine tetraepoxide, 4,4'-diaminodiphenylmethane tetraglycidylamine and glycidyl etheroxypropylcyclotetrasiloxane were compounded in a mass fraction of 60:20:30:10, and then mixed with a composite curing agent in a ratio of epoxy group:active hydrogen of amine = 1:1. Finally, 5 parts of the high-temperature resistant modified component were added. The mixing conditions were oil bath 125℃, stirring speed 400r / min, time 10min, vacuum degassing for 15min, and then poured into a metal mold for curing treatment. The curing regime was 90℃ / 1h + 120℃ / 2h + 150℃ / 3h. After natural cooling and demolding, it was polished smooth according to national standards and tested.

[0036] The specific formulation design of each component in this embodiment is shown in Table 2. The test results of the mechanical properties of the casting and other process characteristics of the resin system are shown in Tables 3 and 4. It can be seen from the test data in Tables 3 and 4 that the resin system in this embodiment has good high temperature resistance and mechanical properties, and its process characteristics are suitable for dry winding molding process.

[0037] High temperature resistance comparison example 1-1

[0038] Without adding polyphosphazene curing agent and high-temperature resistant modifier, the proportions of other components and experimental procedures were the same as in Example 1. The comparison shows that the polyphosphazene curing agent and high-temperature resistant modifier significantly improved the high-temperature resistance of the resin system without significantly sacrificing mechanical properties; that is, the resin system of Example 1 has better overall performance.

[0039] High temperature resistance comparison examples 1-2

[0040] The preparation methods for the polyphosphazene curing agent and the high-temperature resistant modifying component were the same as in Example 1; diethyltoluene diamine, 4,4'-diaminodicyclohexylmethane, and polyphosphazene were mixed at a mass ratio of 40:7.5:9, and the remaining experimental steps were the same as in Example 1. The comparison shows that increasing the polyphosphazene component content significantly improves the high-temperature resistance of the system, but excessive addition can lead to agglomeration and loss of mechanical properties.

[0041] Example 2 of high temperature resistance performance

[0042] The preparation methods for the polyphosphazene curing agent and the high-temperature resistant modifying component are the same as in Example 1; diethyltoluene diamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and polyphosphazene are mixed in an optimal ratio of 40:5:2.5:6 and added to a beaker with mechanical stirring. The mixture is heated to 80°C, stirred at 600 r / min for 45 min to obtain a composite curing agent; poly[(phenyl glycidyl ether)-co-dicyclopentadiene], 1,5-naphthyldiamine tetraepoxide, and 5,5'-dimethyl-1,3-di(ethylene oxide) Methylimidazolium-2,4-dione and glycidyl etheroxypropylcyclotetrasiloxane were compounded in a mass fraction of 60:20:30:10, and then mixed with a composite curing agent in a ratio of epoxy group to active hydrogen of amine of 1:1. Finally, 5 parts of high-temperature resistant modifying component were added. The mixing conditions were: oil bath at 125℃, stirring speed at 400r / min, time of 10min, vacuum degassing for 15min, and then poured into a metal mold for curing treatment. The curing regime was 90℃ / 1h + 120℃ / 2h + 150℃ / 3h. After natural cooling and demolding, the surface was polished smooth according to national standards and tested.

[0043] The specific formulation design of each component in this embodiment is shown in Table 2. The test results of the mechanical properties of the casting and other process characteristics of the resin system are shown in Tables 3 and 4. It can be seen from the test data in Tables 3 and 4 that the resin system in this embodiment has good high temperature resistance and mechanical properties, and its process characteristics are suitable for dry winding molding process.

[0044] High temperature resistance comparison example 2-1

[0045] Without adding polyphosphazene curing agent and high-temperature resistant modifier, the proportions of other components and experimental procedures were the same as in Example 2. The comparison shows that the addition of polyphosphazene in Example 2 helps improve the high-temperature resistance of the resin system, and compared with Example 1, hydantoin epoxy is beneficial to enhancing the tensile properties and rheological processability of the material system.

[0046] High temperature resistance comparison example 2-2

[0047] The preparation methods for the polyphosphazene curing agent and the high-temperature resistant modifying component were the same as in Example 1; diethyltoluene diamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and polyphosphazene were mixed at a mass ratio of 40:5:2.5:9, and the remaining experimental steps were the same as in Example 2. The comparison shows that as the content of the polyphosphazene component increases, the high-temperature resistance of the system improves significantly, while the mechanical properties are slightly reduced.

[0048] Example 3 of high temperature resistance performance

[0049] The preparation methods for the polyphosphazene curing agent and the high-temperature resistant modifying component are the same as in Example 1; dimethylthiotoluene diamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and polyphosphazene are mixed in an optimal ratio of 40:2.5:5:6 and added to a beaker with mechanical stirring. The mixture is heated to 80°C, stirred at 600 r / min for 45 min to obtain a composite curing agent; poly[(phenyl glycidyl ether)-co-dicyclopentadiene], 1,5-naphthyldiamine tetraepoxide, 4,4'-diaminodiphenylmethane tetraglycidylamine, and 5,5 Dimethyl-1,3-di(epoxyethylenemethyl)imidazolidine-2,4-dione was compounded in a mass fraction of 60:20:15:25, and then mixed with a composite curing agent in a ratio of epoxy group to active hydrogen of amine of 1:1. Finally, 5 parts of high-temperature resistant modifying component were added. The mixing conditions were: oil bath at 125℃, stirring speed at 400r / min, time of 10min, vacuum degassing for 15min, and then poured into a metal mold for curing treatment. The curing regime was 90℃ / 1h + 120℃ / 2h + 150℃ / 3h. After natural cooling and demolding, the surface was polished smooth according to national standards and tested.

[0050] The specific formulation design of each component in this embodiment is shown in Table 2. The test results of the mechanical properties of the casting and other process characteristics of the resin system are shown in Tables 3 and 4. It can be seen from the test data in Tables 3 and 4 that the resin system in this embodiment has good high temperature resistance and mechanical properties, and its process characteristics are suitable for dry winding molding process.

[0051] High temperature resistance comparison example 3-1

[0052] Without adding polyphosphazene curing agent and high-temperature resistant modifier, the proportions of other components and experimental procedures were the same as in Example 3. The comparison shows that the addition of polyphosphazene in Example 3 further improves the high-temperature resistance of the resin system. Compared with Example 1, the significant influence of organosilicon epoxy on rheological processability is evident, and the methylthiolated aromatic amine curing agent system has a longer process window.

[0053] High temperature resistance comparison example 3-2

[0054] The preparation methods for the polyphosphazene curing agent and high-temperature resistant modifying components were the same as in Example 1; dimethylthiotoluene diamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and polyphosphazene were mixed at a mass ratio of 40:2.5:5:9, and the remaining experimental steps were the same as in Example 3. The comparison shows that as the content of the polyphosphazene component increases, the high-temperature resistance of the system improves significantly; however, the lack of adjustment by the organosilicon epoxy component results in a significant loss of mechanical properties.

[0055] Examples of "Smart Adhesion" Characteristics in Prepreg Tape Preparation Process

[0056] The preparation and mixing methods of each component of the resin system were the same as in Example 1; the tests were performed using a rotational viscometer according to standard GB / T12007.4-89, and the results are as follows. Figure 3 As shown in (1), the viscosity of the resin system for dry winding should be higher than 90000 mPa·s at 25°C and lower than 3000 mPa·s at 80°C.

[0057] Comparative example of the "smart adhesion" characteristics of prepreg tape manufacturing process

[0058] The commonly used wet winding resin system was prepared as follows: Bisphenol A diglycidyl ether (CYD128) and diethyltoluene diamine were mixed evenly at a mass ratio of 100:24; the mixture was tested using a rotational viscometer according to standard GB / T 12007.4-89, and the results are as follows. Figure 3 As shown in (2), the viscosity of the wet winding resin is much lower than that of the dry winding resin at both low and high temperatures.

[0059] Example of the "intelligent adhesion" characteristic of the prepreg yarn feeding process

[0060] The prepreg tape roll material prepared using the resin system of Example 1 was selected, and the resin volume fraction of the prepreg tape was controlled to be 28±2% by adjusting the process parameters. Figure 1 The parallel traction test shown has the following yarn release results: Figure 1 As shown in case (1), there is no excess glue on the surface of the prepreg tape, the edge regularity is high, and there is no fuzzing when the yarn is laid out. According to the method in Table 1, it is rated as "excellent".

[0061] Comparative Example 1: "Smart Adhesion" Characteristics of Prepreg Yarn Feeding Process

[0062] The prepreg tape roll prepared from the resin system of Example 1 was selected, and the precision of process parameter adjustment was reduced to make the resin volume fraction of the prepreg tape 35±5%. The following method was employed: Figure 1 The parallel traction test shown has the following yarn release results: Figure 1As shown in case (2), there is a small amount of glue overflow on the surface of the prepreg tape, the edge regularity is average, and there is a small amount of fuzzing when the yarn is laid out. According to the method in Table 1, it is rated as "average".

[0063] Comparative Example 2: "Smart Adhesion" Characteristics of Prepreg Yarn Feeding Process

[0064] The resin system of Example 1 was selected without the addition of glycidyl etheroxypropyl cyclotetrasiloxane, and the process parameters were adjusted with reduced precision to achieve a resin volume fraction of 35±5% in the prepreg tape. The following method was employed: Figure 1 The parallel traction method shown was used to test the prepreg tape, and the yarn release results are as follows: Figure 1 As shown in case (3), the surface of the prepreg tape has a lot of glue overflow and is uneven, the edges are not neat and often have adhesion and damage, and the yarn is severely fuzzy when it is laid out. According to the method in Table 1, it is rated as "very poor".

[0065] Examples of the "smart adhesion" characteristics of prepreg tape winding process

[0066] Prepreg tape rolls prepared with the resin system of Example 1 were selected for variable angle and variable tension winding tests. Each time, the winding angle was fixed and the spiral winding was carried out. The tension was gradually increased from 10N to 100N. The prepreg tape did not slip during spiral winding at 15-90 degrees.

[0067] Comparative example of the "smart adhesion" characteristics of prepreg winding process

[0068] Using the "intelligent adhesion" characteristic of the prepreg tape preparation process, variable-angle and variable-tension winding tests were conducted on the resin system used in the wet winding process in the comparison ratio. Helical winding was performed at a fixed winding angle each time, with tension gradually increased from 10N up to 100N. It was observed that in wet winding, when the winding angle is less than 45 degrees, yarn slippage occurs once the tension exceeds 50N. The direction of the slippage tendency is as follows... Figure 2 As shown.

[0069] Table 2. Mass fractions of each component in the examples and comparative examples.

[0070]

[0071] Table 3. Performance test results of the resin adhesives in the examples and comparative examples.

[0072]

[0073] Table 4. Results of mechanical property tests on resin castings from the examples and comparative examples.

[0074]

Claims

1. A high-temperature resistant resin system for dry-wound prepreg tape, characterized in that, The resin system comprises a resin matrix, a composite curing agent, and a high-temperature resistant modifying component. Its characteristic feature is that the resin system formulation is as follows: 100 parts resin matrix, 10-50 parts composite curing agent, and 1-15 parts high-temperature resistant modifying component; the composite curing agent consists of a main curing agent component and a latent polyphosphazene curing agent; the high-temperature resistant modifying component is one of cobalt phthalocyanine, copper phthalocyanine, iron phthalocyanine, or zinc phthalocyanine with a multi-amino structure. The resin matrix is ​​composed of a main resin and a component resin mixed in a mass ratio of 60-100:10-50. The main resin is a compound of dicyclopentadiene-type phenolic epoxy and multifunctional naphthalene ring epoxy resins, and the component resins are a compound of one or more of glycidylamine-type, hydantoin-type, and organosilicon-modified epoxy resins. The latent polyphosphazene curing agent is an organic / inorganic hybrid polymer with a phosphazene ring and an aromatic ring structure. An aromatic diamine monomer (hereinafter referred to as A2 monomer) and a hexafunctional monomer with a phosphazene ring structure (hereinafter referred to as B6 monomer) are selected. The reactive group of B6 monomer is polymerized with the amino group of A2 monomer to prepare a terminal amine curing agent with a hyperbranched structure and a size of 200-800 nm. Alicyclic or aromatic diisocyanate is used as the end-capping agent to obtain a polyphosphazene curing agent with room temperature latency. The high-temperature resistant modified component uses nitrophthaloyl derivatives, urea, metal chlorides and catalysts as reaction raw materials. The terminal nitro phthalocyanine intermediate is prepared by microwave heating, and then the nitro group is converted to amino group by a reducing agent to obtain the terminal amino metal phthalocyanine high-temperature resistant modified component. The main curing agent component is a compound of one or more of high-temperature resistant aromatic amines and alicyclic amines. The main curing agent component and the latent polyphosphazene curing agent component are mixed evenly by mechanical stirring at a mass ratio of 100-120:1-30 to obtain the composite curing agent.

2. A method for preparing a high-temperature resistant resin system for dry-wound prepreg tape, used to prepare the high-temperature resistant resin system for dry-wound prepreg tape as described in claim 1, characterized in that, The preparation process is as follows: (1) Preparation process of resin matrix: The resin matrix is ​​made by mixing the main resin and the component resin, wherein the main resin is 60-100 parts and the component resin is 10-50 parts. The mixture is heated to 80-150 ℃ and mechanically stirred at a speed of 300-600 rpm for 5-15 min until the system is uniform and transparent, and a resin matrix with suitable viscosity and viscosity is obtained. (2) Preparation process of latent polyphosphazene curing agent: Tetrahydrofuran, N,N'-dimethylformamide or acetonitrile are selected as solvents. A2 monomer and B6 monomer are reacted at 40-80 ℃ for 4-8 h at a mass ratio of 2.5-2.8:1-1.

2. The precipitate is separated, washed and dried. Then the product is heated with diisocyanate end-capping agent in dimethyl sulfoxide or N,N'-dimethylformamide to 60-80 ℃ for 0.5-3 h to end-cap, and latent polyphosphazene curing agent can be obtained. (3) Preparation process of composite curing agent: The main curing agent component is selected from high temperature resistant aromatic amines and alicyclic amines with a room temperature viscosity of less than 1000 mPa‧s. The main curing agent component and the latent polyphosphazene curing agent are mixed and prepared in a mass ratio of 100-120:1-30. The mixture is heated to 80-180 ℃ and mechanically stirred for 10-30 min to obtain a uniform and stable composite curing agent. (4) Preparation process of high temperature resistant modified component: Nitrophthaloyl derivative, urea, metal chloride and catalyst are selected as reaction raw materials. The raw materials are mixed evenly and reacted at 160-200 ℃ for 1-3 h. After washing the obtained nitrophthalocyanine intermediate, a reducing agent is added and reacted for 1-3 h. The product is washed and purified to obtain the high temperature resistant modified component of terminal amino metal phthalocyanine. (5) Preparation process of high temperature resistant resin system: The resin matrix obtained in step (1), the composite curing agent obtained in step (3) and the high temperature resistant modified component obtained in step (4) are mixed at a mass ratio of 100:10-50:1-15, heated and stirred at 60-120℃ for 10-15 min to obtain a resin system for dry winding with excellent high temperature resistance.

3. A dry-wound prepreg tape, prepared from the resin system obtained by the method of claim 2, characterized in that, The processability of the prepared resin system and the "smart adhesion" characteristics of the prepreg tape were evaluated using the following methods: (1) Preparation of "intelligent adhesion" characteristic test: The resin system used to prepare the prepreg tape was tested at 25℃ and 80℃ according to the rotational viscosity method in GB / T 12007.4-89, and evaluated according to the viscosity; the viscosity at 25℃ should be higher than 90000 mPa‧s, and the viscosity at 80℃ should be lower than 3000 mPa‧s. (2) Yarn release "smart adhesion" characteristic test: Simulate the actual use scenario of prepreg roll material, and under tension of 10-50 N, the prepreg roll is tested by parallel traction yarn release. The evaluation is based on the adhesion of the prepreg roll, the amount of resin overflow on the surface, the amount of fuzzing and the edge regularity during yarn release. (3) Test of the "intelligent adhesion" characteristic of winding: Simulate the actual dry winding scenario, use the prepared prepreg tape to carry out variable angle winding of 15-90 degrees under tension of 10-100 N, and evaluate the prepreg tape on the mandrel based on the slippage of the prepreg tape.

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