WO2008011765A1 - A toughened composite material laminate and a process of preparation thereof - Google Patents

Abstract

A composite material laminate and a process of preparation thereof. The laminate comprises at least one carbon fiber reinforced matrix resin layer and at least one toughened resin layer. The toughened resin layer includes at least one of the following components: thermoplastic resin of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, polyether imide, polycarbonate, polyphenyl ether, polyamide and the like, or a mixture of at least one of above thermoplastic resin with thermosetting resin of epoxide resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanate resin, unsaturated polyester resin and the like.

Description

 Toughened composite material laminate and preparation method thereof

Technical field

 The invention relates to a toughened resin-based composite material laminate and a preparation method thereof.

 Background technique

 Fiber reinforced resin-based composite laminates are increasingly used in a wide range of applications, especially in the aerospace industry, where a variety of aircraft are heavily carbon fiber composite structures. The general defect of such materials is that the toughness is low, and the performance of the low-speed impact damage is not good, which restricts the further expansion of its application range. In order to solve this problem, various improvements have been proposed, such as development of a new high-toughness matrix, toughening modification of existing material systems, and the like, and thus, some high-toughness composite laminates have been produced. However, the development of new resin systems not only involves huge investment, high risk, but also convincing the industry to abandon existing mature materials and switch to new material systems, which is neither economical nor quite difficult. Therefore, toughening based on the existing system is the most realistic choice.

The conventional toughening technique is to introduce a high toughness component such as a rubber or a thermoplastic resin into a low-toughness matrix (mostly a thermosetting resin) to form a two-phase or multi-phase structure to improve the toughness of the resin as a whole. In terms of component selection, toughening with a rubber phase affects the temperature resistance of a multiphase system, so a high performance matrix resin is usually toughened with a thermoplastic resin. A large number of studies have shown that if the volume fraction ratio of the thermoplastic toughening resin is increased, and the thermodynamic "phase separation" is formed to form a bicontinuous, oppositely rotating granular "roughening" structure in which the thermoplastic phase is wrapped with the thermosetting phase, the toughening is obtained. The effect will be significantly improved. Therefore, the traditional toughening technique is a toughening technique that is "integral" in the spatial position. The technical basis is to use "phase separation" and "roughening" on the basis of thermodynamics and dynamics of the two-component material system. The mechanism, and "phase separation" and "roughening" all occur in any spatial position of the system. Therefore, this toughening technique is "in situ". However, this will bring two problems: First, after the introduction of a large amount of thermoplastic components, the processability of the toughened matrix is significantly degraded, which brings many difficulties to the construction of the composite material; Second, the chemical composition changes and the phase structure after solidification The changes that make the control of the new structure very complex are tantamount to developing a new material. Moreover, both of these problems inevitably increase material costs and process costs. Confirmation Summary of the invention

 The research indicates that the main reason for the impact damage of low-toughness carbon fiber composite laminates is that the interlaminar resin has insufficient toughness, and it is easy to cause failure to cause interlayer delamination during impact events, which greatly reduces the rigidity of the laminate structure and finally reduces compression. Destruction under stress, and composite structures of different scales and layers play different roles on the macroscopic properties of composite laminates. Therefore, toughen such weak points between layers, it is expected to greatly improve composite laminates. Resistance to delamination damage. Based on this idea and in response to the problems of traditional toughening techniques, the following solutions are proposed:

 First, separation of functional components: Separation of the toughener component from the resin matrix component, but giving full play to the functional properties of the respective components, allowing the toughener component to be sufficiently toughened and the resin matrix component to maintain its high strength The high modulus property does not change, and does not cause intermediate properties between the two due to direct mixing (the necessary link of traditional toughening techniques).

 Second, the separation of the layer structure function: Make full use of the periodic nature of the overall laminate material in the thickness direction, and in the selection of the type and properties of the component materials, the material structure and the toughness determining layer of the specific stiffness and specific strength are determined. The materials are separated in function, and the respective structures correspond to the most suitable resin component materials.

 Third, "periodic" or "non-periodic" structural optimization: on the basis of functional optimization design of the separated components and layer structures, the "periodic" or "non-periodic" of layer materials and layer structures Re-integration. The "periodicity" herein is embodied in a layered material system composed of a carbon fiber reinforcement, a resin matrix component and a toughener component having a periodicity in the thickness direction. Among them, if the laminate system composed of the toughening component and the matrix component has a very large number of "frequency" in the thickness direction, it is defined as a "non-periodic" laminated material system. This is "structural optimization."

Fourth, prefabrication integration: Elimination of the preparation and preparation of traditional multi-component resin matrix, and the integration of toughening modification into a prefabrication process in the composite lamination process. In other words, there is no toughened matrix resin system (traditional toughening technique) in advance, and then it is used to wet the carbon fiber layer and recombine, but to obtain a "cycle" or "non-periodic" prefabricated layer. And then compositely prepared into a composite laminate. That is to say, there is no need to have a homogeneous window of the two-component material on the phase diagram as in the conventional toughening technique, and then "phase separation" and "thickness" in thermodynamics and kinetics of the two-component material. "Mechanization" toughening, but in the process of preparing composite materials, starting from the coexisting two-component, two-phase materials, coexisting The two-component, two-phase material state ends; the possible "homogeneous" is only one of the very short-lived processes and has no effect on the final phase structure.

 Fifth, strengthen the weak structure: Identify the load of different parts of the composite material, and use the toughening component for local toughening and strengthening treatment in areas where special toughening is required, such as open holes, edges and other weak structural parts.

 Therefore, from the perspective of compounding, compared with the traditional "in situ" toughening technology, the above technical solution belongs to a kind of "off-position, toughening technology, for a selective, full play on the basis of structural design. Toughening technology optimized for multi-layered, multi-scale components and structures of composite materials.

 Based on the concept of "off-site" toughening, an object of the present invention is to provide a composite laminate comprising at least one carbon fiber reinforced matrix resin layer and at least one toughening resin layer, wherein the toughening resin layer comprises at least one The following components: polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, polyetherimide, polycarbonate, polyphenylene ether, polyamide and other thermoplastic resins, or epoxy resin, bismales A mixed resin system of a thermosetting resin such as an imide resin, a thermosetting polyimide resin, a phenol resin, a cyanate resin, or an unsaturated polyester resin, and at least one of the above thermoplastic resins.

 Another object of the present invention is to provide a method of preparing a composite laminate comprising at least one carbon fiber reinforced matrix resin layer and at least one tough resin layer, the method comprising:

 a preformed material comprising at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, polyetherimide, polycarbonate, poly a thermoplastic resin such as phenyl ether or polyamide, or a thermosetting resin such as an epoxy resin, a bismaleimide resin, a thermosetting polyimide resin, a phenol resin, a cyanate resin, or an unsaturated polyester resin, and at least one of the above a mixed resin system of a thermoplastic resin;

 b. The structural material is composited to a carbon fiber reinforced matrix resin and cured in accordance with the curing process of the original carbon fiber reinforced matrix resin.

DRAWINGS

 Figure 1 illustrates the comparison of the basic idea of "in situ" toughening and "off-site" toughening.

Figure 2 illustrates the "in situ" toughening and "off-site" toughening process technology, where TS is heat A solid resin, TP is a thermoplastic resin.

 Figure 3 shows the morphological distribution of the typical resin matrix phase of the "off-site" toughened composite.

 Figure 4 shows the typical interlayer morphology of an "off-site" composite.

detailed description

 The present invention provides a composite laminate comprising at least one carbon fiber reinforced matrix resin layer and at least one toughened resin layer, wherein the toughened resin layer comprises at least one of the following components: polyether ketone, polysulfone, polyether sulfone, Thermoplastic polyimide, polyetherimide, polycarbonate, polyphenylene ether, polyamide, etc., or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanide A mixed resin system of a thermosetting resin such as an acid ester resin or an unsaturated polyester resin and at least one of the above thermoplastic resins.

 In a preferred embodiment of the invention, the toughening resin layer is formed in a thermoplastic phase or a thermoplastic phase (the thermoplastic component phase is between 10% and 75% by weight of the toughened resin layer, preferably between 10% and 50% More preferably between 15% and 35%) is a continuous or double-continuous structure of the continuous phase and forms a physical interpenetration and connection with adjacent matrix resin layers (eg IPN, Semi- IPN, etc., having a thickness of 0.1 μm - 25 μm, preferably 0.5 μm - 20 μmη, more preferably 1 μηη - 10 μιη.

 In a preferred embodiment of the invention, the carbon fiber reinforced matrix resin layer comprises at least one resin selected from the group consisting of epoxy resins, bismaleimide resins, thermosetting polyimide resins, phenolic resins, cyanic acid Ester resin, unsaturated polyester resin, etc., using a thermoplastic component such as polyether ketone, or polysulfone, or polyether sulfone, or thermoplastic polyimide, or polyetherimide, or polycarbonate, or polyphenylene Ether, or polyamide, etc., even using an epoxy resin, or a bismaleimide resin, or a thermosetting polyimide resin, or a phenolic resin, or a cyanate resin, or an unsaturated polyester resin, etc. A mixed resin system of a thermoplastic resin or the like.

In a preferred embodiment of the invention, the toughened resin layer is a preformed structural material composed of at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, poly Thermoplastic resin such as etherimide, polycarbonate, polyphenylene ether, polyamide, or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanate resin, unsaturated poly A mixed resin system of a thermosetting resin such as an ester resin and at least one of the above thermoplastic resins. In a preferred embodiment of the invention, the preformed structural material of the toughened resin layer is a film, a glue, a felt or a powder, in the form of a separate structural material, a loose toughened layer attached to the paper base, or a woven structure. Toughened material.

 In an embodiment of the present invention, the toughening agent further includes other functional components, such as a binder, a styling agent, an electromagnetic wave reflector, an absorbent, or a conductive agent, a thermal conductive agent, a magnetic conductive agent, etc., to achieve compounding. Multifunctionalization of materials.

 The specific form of the composite laminate of the present invention may be "a layer of carbon fiber reinforced matrix resin layer - a toughened resin layer" or a layer of carbon fiber reinforced matrix resin layer - a toughened resin layer A layer of carbon fiber reinforced matrix resin layer, or "a layer of carbon fiber reinforced matrix resin layer - a layer of toughened resin layer - a surface layer", and any repeated repetition of the above three forms. However, regardless of the form, it is within the scope of the present invention to include at least one layer of a carbon fiber reinforced matrix resin layer and at least one layer of a toughening resin layer.

 The present invention also provides a method of preparing a composite laminate comprising a carbon fiber reinforced matrix resin layer and at least one toughened resin layer, the method comprising:

 a preformed material comprising at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, polyetherimide, polycarbonate, poly a thermoplastic resin such as phenyl ether or polyamide, or a thermosetting resin such as an epoxy resin, a bismaleimide resin, a thermosetting polyimide resin, a phenol resin, a cyanate resin, or an unsaturated polyester resin, and at least one of the above a mixed resin system of a thermoplastic resin;

 b. The structural material is composited to a carbon fiber reinforced matrix resin and cured in accordance with the curing process of the original carbon fiber reinforced matrix resin.

In a preferred embodiment of the method of the present invention, the carbon fiber reinforced matrix resin layer comprises at least one resin selected from the group consisting of epoxy resins, bismaleimide resins, thermosetting polyimide resins, phenolic resins, cyanogens An acid ester resin, an unsaturated polyester resin or the like, using a thermoplastic component such as polyether ketone, or polysulfone, or polyether sulfone, or thermoplastic polyimide, or polyetherimide, or polycarbonate, or poly Phenylene ether, or polyamide, etc., even using an epoxy resin, or a bismaleimide resin, or a thermosetting polyimide resin, or a phenolic resin, or a cyanate resin, or an unsaturated polyester resin, etc. A mixed resin system of a thermoplastic resin, and the like. In a preferred embodiment of the method of the invention, the toughening resin layer is a preformed structural material composed of at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, Thermoplastic resin such as polyetherimide, polycarbonate, polyphenylene ether, polyamide, or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanate resin, unsaturated A mixed resin system of a thermosetting resin such as a polyester resin and one of the above thermoplastic resins.

 In a preferred embodiment of the process of the invention, at least one of the following methods is employed in the step of "preforming a material comprising at least one component selected from the group consisting of:" , hot melt coating, cast film formation, spray film formation, film formation, fluidized bed sedimentation, electrostatic powder adsorption, to obtain film, glue, felt or powder, as an independent structural material, loose attached to the paper base Toughening material in the form of a toughened layer or a fabric structure.

 In a preferred embodiment of the method of the invention, the structural material is composited to the matrix resin using at least one of the following methods: spraying, sedimentation, electrostatic adsorption or printing means that the toughening material forms a toughened layer on the substrate material The structure, which is subsequently cured, gives a toughened composite.

 In a preferred embodiment of the process of the invention, a RTM (Resin Transfer Molding) / RFI (Resin Film Infusion) liquid forming system is employed. Among them, various methods and methods such as solution film formation, or hot melt coating, or casting film formation, or spray film formation, or printing film formation, or fluidized bed sedimentation, or electrostatic powder adsorption, are added in the dry state. A thin layer of toughened resin is obtained on the sheet of tough material. According to the original injection process, the injection molding is carried out, and the curing is carried out according to the original curing system to obtain a toughened composite material.

 In a preferred embodiment of the process of the invention, in the "a. preforming a material comprising at least one component selected from the group consisting of: a structural material", a thermoplastic component phase or a thermoplastic component phase (thermoplastic component phase) Forming a toughened resin layer in the carbon fiber reinforced composite material between 10% and 75%, preferably between 10% and 50%, more preferably between 15% and 35% by weight of the toughened resin layer, optionally forming It is a continuous or reversed structure of the continuous phase, and optionally forms a physical interpenetration and connection with an adjacent matrix resin layer (for example, IPN.Semi-IPN, etc.), and its thickness is controlled at 0.1 μηι - 25 μπι, preferably 0.5 μηη -20 μιη, more preferably 1 μιη - 10 μιη.

In the method of the present invention, when preparing the toughened resin layer, it further includes adding other functional components such as a binder, a styling agent, an electromagnetic wave reflecting agent, an absorbent, or a conductive agent, a thermal conductive agent, A magnetic permeability agent or the like to achieve multifunctionalization of the composite material.

 In the method of the present invention, the toughening component can be formed into various forms such as a film, a powder, a glue, a felt, etc., and can be applied by a plurality of means such as paving, spraying, painting, printing, etc. Prefabricated composites of the reinforcement layer, including composite prepregs or dry reinforcement sheets.

 In the present invention, the carbon fiber reinforced matrix resin layer may be any carbon fiber reinforced resin layer, and as long as the matrix resin meets the needs of the present invention, the reinforcing method may also employ a method known in the art.

 The curing process of the carbon fiber reinforced composite material may employ any known curing method for such a resin.

 In the present invention, a preferred carbon fiber reinforced matrix resin layer comprises at least the following resins: an epoxy resin, a bismaleimide resin, a polyimide resin, a cyanate resin, a polyamide resin and the like. Meanwhile, the toughening layer includes at least one of the following resins: polyether ketone, polysulfone, polyether sulfone, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polyamide, and the like.

In the present invention, a more preferred combination of the carbon fiber reinforced matrix resin layer-toughening layer is: a carbon fiber reinforced epoxy resin layer - a polyether ketone layer, a carbon fiber reinforced epoxy resin layer - a polysulfone layer, and a carbon fiber reinforced layer. Epoxy layer - polyether sulfone layer, carbon fiber reinforced epoxy layer - polyimide layer, carbon fiber reinforced epoxy layer - polyetherimide layer, carbon fiber reinforced epoxy layer - polycarbonate Ester layer, carbon fiber reinforced epoxy resin layer - polyphenylene ether layer, carbon fiber reinforced epoxy resin layer - polyamide layer; carbon fiber reinforced bismaleimide resin layer - polyether ketone layer, carbon fiber reinforced double horse Imide resin layer-polysulfone layer, carbon fiber reinforced bismaleimide resin layer-polyethersulfone layer, carbon fiber reinforced bismaleimide resin layer-polyimide layer, carbon fiber reinforced double Maleimide resin layer-polyetherimide layer, carbon fiber reinforced bismaleimide resin layer-polycarbonate layer, carbon fiber reinforced bismaleimide resin layer-polyphenylene ether layer, carbon fiber Reinforced bismaleimide resin layer-polyamide layer; Fiber-reinforced polyimide resin layer-polyetherketone layer, carbon fiber-reinforced polyimide resin layer-polysulfone layer, carbon fiber-reinforced polyimide resin layer-polyethersulfone layer, carbon fiber-reinforced polyimide Amine resin layer-polyimide layer, carbon fiber reinforced polyimide resin layer-polyetherimide layer, carbon fiber reinforced polyimide resin layer-polycarbonate layer, carbon fiber reinforced polyimide resin Layer - polyphenylene ether layer, carbon fiber reinforced polyimide resin layer - polyamide layer; carbon fiber reinforced cyanate resin layer - polyether ketone layer, carbon fiber reinforced cyanate Resin layer-polysulfone layer, carbon fiber reinforced cyanate resin layer-polyethersulfone layer, carbon fiber reinforced cyanate resin layer-polyimide layer, carbon fiber reinforced cyanate resin layer-polyetherimide Layer, carbon fiber reinforced cyanate resin layer-polycarbonate layer, carbon fiber reinforced cyanate resin layer-polyphenylene ether layer, carbon fiber reinforced cyanate resin layer-polyamide layer, and the like.

 Compared with the conventional overall toughening method and the product obtained by the method, the off-site toughening method and the product thereof of the invention do not greatly adjust the chemical composition, the process system and the product structure of the original composite material, and The toughness is greatly improved only by selectively introducing a toughened structure at its relatively weak interlayer region, while other indicators (such as static mechanical properties, wet/heat properties, preparation processes, etc.) remain substantially unchanged. Therefore, the off-site toughening method pursues a phase-separated structure that is limited to layers and has a periodicity and design. The structure is located between the designated layers and forms an integral layer with the adjacent laminate layers rather than a separate resin layer. Inside the structure, it appears as a reverse-transformed morphology in which the thermoplastic resin phase or the thermoplastic-rich resin phase is a continuous phase; this reverse-transformation may penetrate into adjacent layups, but is preferably limited to a very shallow range. Moreover, the thickness of the toughened structure is preferably as thin as possible to prevent adverse effects on the thickness and weight loss efficiency of the composite material.

 The method of the present invention is applicable to both a conventional prepreg system and a liquid forming technique such as RTM/RF I; it may be a post-treatment step of a composite material raw material, or may be a stage of a preparation process of a composite material structure.

 In one embodiment of the invention, the method of the invention is used in prepreg recombination. The use of off-site toughening technology in prepreg composites basically eliminates the need to make major adjustments to the original production regulations. The prepreg is still produced according to the original process. At this time, the off-site toughening is Post-treatment of existing prepregs, or additional steps in the preparation of composites. The following two cases are explained.

 When post-processing existing prepregs directly, the following steps are included:

 a) selecting an effective toughening agent according to the prepreg base resin;

 b) according to the physicochemical properties of the selected toughening agent, it is made into a powder, or dissolved in a solvent, or heated to marry;

 c) in the prepreg production process, adding a post-release treatment step between the pre-dip and the winding, coating the toughener powder / solution / melt on the surface of the prepreg;

d) The toughening agent is wound after being fixed on the surface of the prepreg. In this way, the obtained prepreg can be The composite material is prepared directly according to the original process.

 As an additional step in the preparation of the composite, for example, it can be carried out as follows:

 a) selecting an effective toughening agent according to the prepreg base resin;

 b) according to the physicochemical properties of the selected toughening agent, using a solution casting or hot-melt coating method to form a toughened film having a certain strength;

 c) inserting a toughening film between the desired laminates according to design requirements in the preparation of the composite material using the prepreg;

 d) curing according to the original curing system to obtain a composite product.

 In one embodiment of the invention, the method of the invention is used in RTM/RFI preform compounding. In the liquid forming process represented by RTM/RFI, the off-site toughening technique is applied, and the pre-formed fabric needs to be pre-treated before injection/impregnation, which can be implemented as follows:

 a) selecting an effective toughening agent based on the RTM/RFI resin;

 b) according to the physicochemical properties of the selected toughening agent, it is made into a powder, or dissolved in a solvent, or heated and melted;

 c) pre-treating the reinforced fabric to coat the toughener powder/solution/melt on the surface of the fabric; during this process, reasonable process conditions are controlled to ensure that the resulting fabric has sufficient permeability in the thickness direction;

 d) The treated fabric is made into a preform, and injection/impregnation is carried out according to the original process. A composite article is obtained after curing.

 Regardless of the preparation method used, the resulting composite material has a typical resin matrix phase morphology distribution as shown in FIG. That is, in the position where the toughening effect is required, there is a phase structure which is advantageous for the improvement of the toughness (inter-layer portion in Fig. 3); and for other parts, the original composition and the phase structure should be maintained without introducing any new changes.

The product of the invention can be used as an aerospace composite material, can also be used to upgrade a low-toughness composite material for active toughness to a high-toughness composite material, can also realize an optimized design and selective toughening of the toughened structure, and even add a composite material when necessary. With special features. For the upgrade of low toughness composites, the method does not substantially change the basic component system of existing low toughness composites, and the preparation The process and its parameters, the design structure of the corresponding parts, etc., while maintaining the in-plane mechanical properties and wet/heat properties of the original low-toughness material, greatly improving the interlayer toughness and impact damage resistance, and low-cost Achieve high performance of low-performance composite materials.

 The invention will now be further described in detail by way of examples.

Example 1

 First, a low-toughness composite was prepared as a matrix material: T300/epoxy prepreg was prepared by wet method using a TB-1 wound prepreg (EP-80: E-54: DDS = 60: 40) : 40 ), isotropically laid in accordance with the [45/0/-45/90]« method. Curing and forming in the autoclave, the molding process: vacuuming to 0.095 MPa throughout the whole process, heating from room temperature to 130 ° C, heating for 0.5 h, pressing to 0.55 MPa ~ 0.6 MPa, then heating to 180 ° C for 2 h, then The temperature was raised to 200 ° C for 2 h, and finally cooled to below 60 ° C. The heating rate was 1.0 ° C / min - 2.0. C/min.

A toughened film was prepared: Polyethersulfone (PBS) was dissolved in tetrahydrofuran to give a ratio of 5 ° /. The solution was uniformly applied to the upper surface of the horizontally placed industrial film, and the toughened film was obtained after the solvent was naturally volatilized, and the toughness of the toughened film was about 20 g/m ² . The toned toughened film is removed from the industrial film and taken up on a paper tube for use.

 Prepare the same prepreg as the low toughness composite, also in the same way as the [45/0/-45/90]« mode isotropically layered. During the laying process, the toughened film is cut to the same size as the prepreg and inserted between adjacent prepregs. Cured in an autoclave according to the low toughness composite process.

 Anti-impact damage performance test of composite laminates prepared (test specification

SACMA SRM2-88 ) _{0 The} uncomforted basic composite has a CAI strength of 142 MPa, while the CAI strength of the composite toughened by the off-site method is 314 MPa. After comparison, it can be seen that the toughness of the material is significant. Improve, up to 2.2 times the original.

 The cross section of the composite after etching away the thermoplastic component was observed by SEM, and the results are shown in Fig. 4. As can be seen from Figure 4, an ideal phase separation structure appears between the specified layers. Example 2

Prepare a low-toughness composite in an active aircraft structure: This material is supplied in the form of a commercial prepreg (T300/NY9200G), the basic resin system is epoxy, and the specific formulation is unknown. According to the [45/0/-45/90] ₄₃ method, the isotropically layered and solidified in the autoclave. The molding process: vacuuming to 0.095 MPa throughout the whole process, heating from room temperature to 80 °C, after 0.5 h of heat preservation Pressurize 130 °C to 0.55 MPa ~ 0.6 MPa, continue to heat for 0.5 h, then heat up to 130 for 1 h, then The temperature is raised to 180 Ό for 2 h, then the temperature is raised to 200 Ό for 2 h, and finally cooled to below 60 ° C. The heating rate is 1. 0 O /min ~ 2. 0 Ό /ιηϊη

Further preparation of the toughening layer: The polyaryletherketone (ΡΑΕΚ) was dissolved in a tetrahydrofuran/dimercaptocarboxamide mixed solvent to prepare 20 ° /. The solution. This solution was cast-coated on a base paper to form a resin film having a specified thickness. The gravure depth and the number of printing were controlled, and the areal density of the toughened layer was controlled to 20 g/m ² . The obtained paper-based continuous toughening material has a width of 700 faces and a length without limitation, and is directly received after being dried in the line during the production process.

 Use the low toughness composite prepreg provided by the manufacturer, and also use the [45/0/-45/90] «method quasi-isotropic layup. During the paving process, the toughened material is cut to the same size as the prepreg, placed on the surface of the prepreg and heated slightly. After the paper base is removed, the toughening layer has been completely adhered to the prepreg. Continue the paving operation and repeat the insertion process. Curing is carried out in an autoclave according to the aforementioned process of low toughness composite.

 The prepared composite laminates were tested for static mechanical properties and impact damage resistance. The test results are summarized in Table 1. By comparison, it can be seen that the toughness upgrading material of the present invention can be fully used for the toughness upgrade of the active structural composite material for aviation, and the compression strength after impact is increased to 220%. Moreover, the static mechanical properties of the composites were not significantly affected. Table 1 Material test results before and after toughening Performance The present invention Low toughness Test standard

0 °C tensile strength 1 MPa 1489 1486 GB/T3354-1999

0 °C tensile modulus 1 GPa 135 152 GB/T3354-1999

0 C compression strength 1 MPa 1125 1272 GB/T3856-1983

0°C compression modulus 1 GPa 116 131 GB/T3856-1983

0 Ό bending strength 1 MPa 1293 1508 GB/T3356-1999

0°C flexural modulus 1 GPa 98. 6 118 GB/T3356-1999 Interlaminar shear strength 1 MPa 80. 2 55. 0 JC/T773-1982 Compressive strength after impact 1 MPa 314 142 SACMA SRM2-88

G _IC 1 J/m ² · 521 103

G„c 1 J/m ² 937 433 HB7403-1996

Example 3

First, a low-toughness bismaleimide composite was prepared as a matrix material: wrapped with TB-1 T700/Bismaleimide prepreg prepared by wet prepreg, according to [45/0/-45/90] _2S mode, isotropically layered, autoclave curing, molding process: from room temperature The temperature is raised to 180 Ό. When the temperature rises to 120"C, the pressure is 0.4 MPa. When the temperature is raised to 160 ,, the pressure is increased to 0.7 MPa. When the temperature is raised to 180 保温, the temperature is kept for 3 hours. The temperature is further increased to 200 ° C for 5 hours. Vacuum, finally naturally cooled to below 60 ° C to open the mold, the heating rate is 1.5 ° C / min ~ 2. OC / min. The prepared composite sheet is cut into 89 mm x 55 mm specimens, after the impact compression test ( The test specification refers to QMW CAI), the impact energy is 2 J/mm, and the CAI value is 180 MPa.

Preparation of toughening layer: Polyaryletherketone (PAEK) and bismaleimide (BMI) are dissolved in a mixture of acetone: tetrahydrofuran = 1: 4 in a ratio of 60: 40 to prepare a 20% solution. , casting on a smooth plane, after the solvent is naturally volatilized at room temperature to obtain a PAEK/BMI film with a thickness of about 23 μm. The modified prepreg is quasi-isotropically laminated according to the method of [45/0/-45/90] ₂₃ , and a layer of ruthenium/ruthenium film is added between the layers, and the film is solidified according to the process of the comparative example.

The modified composite sheet is cut into 89 mm χ 55 mm specimens for post-impact compression test (test specification refers to QMW CAI), impact energy 2 J/leg, CAI value is 290 MPa _D CAI value is 1.61 before modification Times. Example 4

First, a low-toughness polyimide composite material was prepared as a matrix material: T300/polyimide prepreg was prepared by wet method using a TB-1 winding prepreg, according to [45/0/-45/90] _2S mode. Quasi-isotropically layered, molded and solidified on a hot press, forming process: from room temperature to 205 ° C ~ 210 V, after 2 h of heat preservation, heat up to 240 ° C ~ 250 ° C for 1 h, pressurize to 1.5 MPa ~ 2 MPa, and then warmed to 300 ° C for 2 h, then heated to 325 ° C for 1 h, and finally cooled to below 60 to open the mold. The heating rate is from 1.0 ° C / min to 2.0 ° C / min.

 The prepared composite sheet was cut into 55 mm χ 89 mm specimens for post-impact compression test (test specification with reference to QMW CAI), impact energy 4 J, and impact damage area was examined with SM2000 C-scanner, perpendicular to loading The projection width in the direction is 40 mm, and the CAI value is 212 MPa.

 Further preparation of toughening layer: Polyetherimide (PBI) was dissolved in dichloromethane to give a ratio of 1 ° /. The solution was sprayed onto the upper surface of the T300/polyimide prepreg prepared in the comparative example by a spray gun to obtain a modified prepreg having a coating thickness of about 20 μm. The surface of the modified prepreg still has the viscosity of the polyimide prepreg, and the processability is good.

The modified prepreg was uniformly isotropically laminated according to the [45/0/- 45/90] _2s method, and was molded and molded on a hot press according to the process of the comparative example. Modified composite sheet cut into 55 mm 89 legs Specimen, compression test after impact (test specification refers to QMW CAI), impact energy 4 J, inspection of impact damage area with SM2000 C-scanner, projection width perpendicular to the loading direction is 18 legs, CAI value倍。 Before the modification was 1.46 times. Example 5

 The bismaleimide (BMI) resin of the RTM molding process is toughened. The main ingredients are shown in the table

2.

 Table 2 Toughening RTM Formed Bismaleimide Resin Composition

 Ingredients Amount (parts) Allyl bisphenol A 35 Liquid phase A component

 Thinner 10 toughening agent (PAEK) 15 solid phase B component

 N, N, -4, 4' Diphenylnonane Bismaleimide (BMI) 60 The B component was pre-dispersed (brushed) onto the surface of a T300 carbon fiber solid preform (Hexcel 827). Only the liquid resin A is pressed into the closed mold to complete the filling. In the closed mold, simultaneous infiltration, impregnation, and contact with the B component adhered to the surface of the preform are caused by the liquid resin A.

 After the filling process is completed, the mold is kept closed, and the curing reaction of the two components A and B in the mold is initiated by heating. Curing conditions: to 1. 5. The heating rate of C / min is raised from room temperature to 130 ° C under normal pressure, and kept for one hour while maintaining pressure of 0.22 MPa - hour. Then, the temperature is raised from 130 ° C to 190 ° C at the same rate, while increasing from 0. 20 MPa to 0. 40 MPa, and then holding for 3 h; finally, at a cooling rate of about 2 ° C / min The temperature is lowered, but the pressure is kept constant during the cooling process until it is cooled to room temperature, thereby completing the entire curing process. After the curing reaction is completed, the mold is opened, and the product is taken out.

Mechanical properties data (carbon fiber volume content 55%) of carbon fiber/bismaleimide (BMI) resin laminates prepared by a new process of off-site RTM. Table 3 Mechanical properties of toughened RTM formed bismaleimide composites

 Mechanical properties test results test criteria

 Bending strength 1 MPa 1730 GB/T3356-1999 Interlaminar shear strength 1 MPa 92 JC/T773- 1982

 0 °C tensile strength / MPa 1670 GB/T3354-1999

0 °C tensile modulus 1 GPa 143 GB/T3354-1999

0°C compressive strength 1 MPa 230 GB/T3856- 1983 It is well known that the RTM process is a relatively difficult toughening process, but the compression performance CAI data in the table indicates that the carbon fiber/double maleic acid prepared by the new process of off-site RTM The post-impact compression properties of imine (BMI) resin laminates reach the level of the autoclave process, which is impossible with any known RTM process for carbon fiber/bismaleimide (BMI) resin laminates. of. Example 6

 Chopped fiber reinforced epoxy resin for RTM molding process.

 The main ingredients are shown in Table 4. Table 4 Chopped fiber reinforced RTM molding epoxy resin composition Ingredients (parts)

 618 epoxy resin 90

 Liquid phase A component AG 80 epoxy resin 10

 501 thinner 10

 Curing agent DDS 30

 Solid phase B component

 Nylon chopped fiber 10 Dissolve DDS of solid phase B component in tetrahydrofuran, add nylon chopped fiber, mix and mix, spray and disperse on dry T300 carbon fiber, and heat it slightly to make nylon chopped fiber. Carbon fiber preform. The carbon fiber preform sprayed with the B phase component is placed in a mold, and the temperature is raised to 40 ° C ~ 5 (TC, and only the liquid resin component A is pressed into the closed mold to complete the filling. In the closed mold, at the same time The infiltration, impregnation, and contact of the B component adhered to the surface of the preform or the bundle of fibers in the in-mold reinforcing material by the liquid resin A occurs.

 After the filling process is completed, the mold is kept closed, and the chemical curing reaction of the two components A and B in the closed mold is initiated by heating, and solidified as follows: no'c/ih + iso /sh + isirc/sh + aoo

°C/2h. After the curing reaction is completed, the mold is opened, and the product is taken out. Basic performance data of composites produced (carbon fiber volume content 52%): Table 5 Basic mechanical properties of chopped fiber reinforced RTM formed epoxy composites

 Mechanical properties test results test criteria

 O 'C bending strength 1 MPa 1800 GB/T3356-1999

O'C flexural modulus 1 GPa 150 GB/T3356-1999 Interlaminar shear strength 1 MPa 100 JC/T773-1982

0 °C tensile strength 1 MPa 1800 GB/T3354-1999

0°C tensile modulus 1 GPa 150 GB/T3354-1999 Compressive strength after impact 1 MPa 260 SACMA SRM2-88 Mechanical properties of T300/epoxy composites, especially after impact, due to the addition of nylon chopped fibers (CAI) is greatly improved, which is generally not possible with conventional RTM composites. Example 7

 A toughened RFI composite system was prepared.

 The resin system and toughening materials are shown in Table 6. Table 6 Toughening RFI Forming Epoxy Resin Composition Name Weight Part Code

 AG80 epoxy resin 50 A1

E-5 epoxy resin 50 A2

 DDS 40 A3

 Polyaryletherketone (PAEK) 15 A4 polyaryletherketone (PA ) 15 B

T300 Carbon Fiber C After the epoxy resin/curing agent/PAEK was uniformly melt-mixed in a weight ratio of 100/40/15, a resin film was prepared by a continuous doctor blade method. The Al, A2, A3, and A4 components were uniformly melted and melted, and the resin film A was prepared by a continuous doctor blade method. After dissolving the component B in tetrahydrofuran, a solution of B in tetrahydrofuran was formed, and the solution was used to form a sheet-like fiber preform D (without a cloth) on the TB-1 type wound prepreg and the fiber C. The resin film A and the fiber preform D are laid up in a mold to form a flat plate shape Forming the assembly E.

 The resin was melted and impregnated with the fiber preform (D) under heating (120 ° C) (0·5 MPa), and then heated under pressure (0.5 MPa) until the resin was cured for 2 h. Cooling to 60 Ό. Release the mold.

 The properties of composite sheets are shown in Table 7. Table 7 Toughening RFI Forming Epoxy Composites Basic Mechanical Properties Mechanical Properties Test Results Test Standards

0 °C bending strength / MPa 1650 GB/T3356-1999 Interlaminar shear strength 1 MPa 88 JC/T773-1982

 0 °C tensile strength 1 MPa 1700 GB/T 3354-1999

 0 °C tensile modulus 1 GPa 120 GB/T3354-1999 Compressive strength after impact 1 MPa 250 SACMA SRM2-88 During the experiment, polyaryl ether ketone is a polymer thermoplastic fine powder resin with a molecular weight of about 30,000. When the materials are mixed with Al, A2, A3 and other components, the viscosity of the resin mixture increases sharply when the content of the components is too high. If the dislocation operation is not performed, the resin mixture is difficult to be uniformly formed by the continuous doctor film method. Stable resin film. With the off-site technology, the content of the B component in the resin mixture is reduced, and the viscosity of the resin mixture is suitable for continuous scraping of the film, and the uniformity of the resin film A produced is good, and the film forming process is stable. Due to the off-site technology, the content of the thermoplastic resin in the resin composite material is improved, and the toughness of the resin system is improved. The mixing, film forming and forming processes in the RFI molding process are easy to implement. Example 8

 The toughened layer was also prepared in the same manner as in Example 2 using the commercial prepreg of Example 2. Similarly, a toughening layer was added between the composite layers in the same manner as in Example 2, but not every layer was added, but only the middle 20 layers were toughened, and the upper and lower surfaces of each layer remained unchanged.

 After curing, the CAI test (test specification refers to SACMA SRM2-88) results in 271 MPa, which is 91% higher than the un-toughened base material. The effect is slightly lower than the fully toughened system, but it has fully met the need for toughening. Example 9

Polyaryletherketone/THF solution and T300 carbon fiber, one-way on TB-1 type winding prepreg The winding is prepared into a thin layer material similar to prepreg, and the polyaryl ether ketone content is 8% to 10%. Completed

Stereotype of T300 carbon fiber. The polyaryletherketone is now used as a styling agent. The unidirectional thin-layer sheet after setting is layered according to [45/0/- 45/90] _4s and [0] ₁₆ , using RTM technology, RTM resin is component A in component 6, and component B The DDS system prepares quasi-isotropic and unidirectional composite sheets. The performance measurement results are shown in the table below. Table 8 Toughness RTM Forming Epoxy Composites Basic Mechanical Properties Mechanical Properties Test Results Test Standards

 O'C bending strength / MPa 1600 GB/T3356-1999

 Interlaminar shear strength 1 MPa 88 JC/T773-1982

0 °C tensile strength 1 MPa 1700 GB/T3354-1999

 O'C tensile modulus 1 GPa 110 GB/T3354-1999

 Compressive strength after impact 1 MPa 245 SACMA SRM2-88 Polyaryletherketone resin, in this case, acts as a styling agent, accomplishes the intended function of unidirectional fibers, and at the same time acts as a toughening effect in the composite system. The CAI value (the control system uses RTM resin as a styling agent, the same process is shaped and cured. The composite material has a CAI value of 156 MPa). Example 10

 A T800/5228 (toughened epoxy) open-cell laminate was prepared with a stress concentration at the opening. During the lamination process, a 16 μm thick PAEK film was added between each prepreg near the opening to form a localized off-center toughened structure with a diameter of about 30 mm.

 At the same time, the un-toughened open-cell laminate and the toughened open-cell laminate were subjected to a compression test, and the loading was stopped when the load reached approximately 80% of the maximum compressive strength. The SM2000 C-scanner was used to inspect the damage of the laminate, and it was found that the untoughened laminate showed a large delamination near the opening, while the toughened laminate had only a very small delamination.

Claims

Claim A composite laminate comprising at least one carbon fiber reinforced matrix resin layer and at least one toughening resin layer, wherein the toughening resin layer comprises at least one of the following components: polyether ketone, polysulfone, polyether sulfone , thermoplastic polyimide, polyetherimide, polycarbonate, polyphenylene ether, polyamide and other thermoplastic resins, or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, A mixed resin system of a thermosetting resin such as a cyanate resin or an unsaturated polyester resin and at least one of the above thermoplastic resins.  2. The composite laminate according to claim 1, wherein the toughened resin layer forms a bicontinuous or reversed structure in which the thermoplastic component phase or the thermoplastic component phase is a continuous phase, and forms a physical layer with the adjacent matrix resin layer. The interpenetration and connection between the domains are between 0.1 μηι and 25 μηι.  3. The composite laminate according to claim 2, wherein the carbon fiber reinforced matrix resin layer comprises at least one resin selected from the group consisting of thermosetting epoxy resins, bismaleimide resins, thermosetting polyimide resins, a phenol resin, a cyanate resin, an unsaturated polyester resin, or the like, using a thermoplastic component such as polyether ketone, or polysulfone, or polyether sulfone, or thermoplastic polyimide, or polyetherimide, or polycarbonate Ester, or polyphenylene ether, or polyamide, etc., even using epoxy resin, or bismaleimide resin, or thermosetting polyimide resin, or phenolic resin, or cyanate resin, or unsaturated polyester A mixed resin system or the like of a resin or the like and at least one of the above thermoplastic resins.  4. A composite laminate according to claim 2 or 3, wherein the toughened resin layer is a preformed structural material composed of at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic poly Thermoplastic resin such as imide, polyetherimide, polycarbonate, polyphenylene ether, polyamide, or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanate ester A mixed resin system of a thermosetting resin such as a resin or an unsaturated polyester resin and at least one of the above thermoplastic resins.  The composite laminate according to claim 2 or 3, wherein the preformed structural material of the toughened resin layer is a film, a glue, a felt or a powder, and is a separate structural material, a loose toughened layer attached to the paper base. Or a toughened material in the form of a fabric structure. 6. A method of preparing a composite laminate comprising at least one layer of a carbon fiber reinforced matrix resin layer and at least one layer of a toughened resin layer Includes:  a preformed material comprising at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide, polyetherimide, polycarbonate, poly a thermoplastic resin such as phenyl ether or polyamide, or a thermosetting resin such as an epoxy resin, a bismaleimide resin, a thermosetting polyimide resin, a phenol resin, a cyanate resin, or an unsaturated polyester resin, and at least one of the above a mixed resin system of a thermoplastic resin;  b. The structural material is composited to a carbon fiber reinforced matrix resin and cured in accordance with the curing process of the original carbon fiber reinforced matrix resin.  7. The method according to claim 6, wherein the carbon fiber reinforced matrix resin layer comprises at least one resin selected from the group consisting of thermosetting epoxy resins, bismaleimide resins, thermosetting polyimide resins, phenolic resins, a cyanate resin, an unsaturated polyester resin, or the like, using a thermoplastic component such as polyether ketone, or polysulfone, or polyether sulfone, or thermoplastic polyimide, or polyetherimide, or polycarbonate, or Polyphenylene ether, or polyamide, etc., even using epoxy resin, or bismaleimide resin, or thermosetting polyimide resin, or phenolic resin, or cyanate resin, or unsaturated polyester resin, etc. A mixed resin system or the like of any one of the above thermoplastic resins.  8. The method according to claim 6 or 7, wherein the toughening resin layer is a preformed structural material composed of at least one component selected from the group consisting of polyether ketone, polysulfone, polyether sulfone, thermoplastic polyimide , thermoplastic resin such as polyetherimide, polycarbonate, polyphenylene ether, polyamide, or epoxy resin, bismaleimide resin, thermosetting polyimide resin, phenolic resin, cyanate resin, no A mixed resin system of a thermosetting resin such as a saturated polyester resin and one of the above thermoplastic resins.  9. The method according to claim 6 or 7, wherein at least one of the following methods is employed in the step of "preforming a material comprising at least one component selected from the group consisting of:" Film formation, hot melt coating, cast film formation, spray film formation, film formation, fluidized bed sedimentation, electrostatic powder adsorption, to obtain a film, glue, felt or powder, as a separate structural material, attached to the paper base A toughened material in the form of a loose toughened layer or a fabric structure.  10. A method according to claim 6 or claim 7, wherein the structural material is compounded to the matrix resin using at least one of the following methods: spraying, sedimentation, electrostatic adsorption or printing means toughening the toughened material on the matrix material The layer structure, which is subsequently cured, gives a toughened composite.