A shearable aramid laminate gasket and method of making same

Abstract

The present application relates to a kind of aramid laminated gasket of punching shear processing and its preparation method, including 100-150 parts benzoxazine resin, 10-20 parts epoxy resin, 30-50 parts curing agent, 0.1-2 parts accelerator, 70-130 parts solvent, 0-10 parts graphite, 0-10 parts flame retardant.The mixed system of bisphenol A type benzoxazine resin and bisphenol A epoxy resin is selected as adhesive, while ensuring the adhesive strength, the flame retardant performance is high, and the amount of flame retardant is less, that is, UL-94V-0 grade flame retardant can be realized.At the same time, to improve the punching shear performance of aramid laminated gasket, graphite is used as filler in adhesive, aramid fiber felt and aramid fiber fabric are used in a specific ratio, and a specific pressing process is used, aramid fiber felt is used as inner support, the shear stress of punching shear blade to aramid plain fabric is improved, and the obtained sample has no burr and burr after punching shear processing, and the convenient punching shear processing of aramid laminated gasket is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of cuttable aramid laminated gasket and its preparation method, belong to functional composite material technical field. BACKGROUND

[0002] Aramid refers to aramid fiber, and carbon fiber, ultra-high density polyethylene are called three high-performance fibers, with lightweight, high strength, high modulus, high temperature resistance and other advantages, cause the attention and interest of industry and academia, can be widely used in military, security, ship, aerospace and other fields.

[0003] Aramid can be divided into meta-aramid (1313) and para-aramid (1414) according to the position of amide bond, wherein meta-aramid is mainly used in the field of fire protection due to its flame retardant properties, and para-aramid is in the form of fabric, aramid paper and aramid-based composite materials due to its high toughness and modulus.

[0004] A variety of composites can be prepared using aramid fiber as reinforcing material and epoxy resin, phenolic resin, benzoxazine resin, etc. as adhesive. With the help of the significant characteristics of aramid fiber itself, such as self-extinguishing, high strength, wear-resistant and insulating, the composite material can be used as a high-performance wear-resistant insulating gasket.

[0005] At the same time, due to the high toughness and high strength of aramid fiber and fabric, the composite material exhibits high impact strength and tear resistance. When machining such as cutting, drilling and polishing is carried out on a traditional machine tool, a large amount of burrs and burrs will be generated, i.e. it is difficult to process the material by traditional machining method.

[0006] In addition, based on the high wear resistance and high insulation of aramid products, the thin plate is used in important components such as V-shaped ring, angle ring and gap gasket in motor, transformer and rail transit equipment. However, aramid thin plate is difficult to be processed by punching and shearing, which increases the processing cost and reduces the precision.

[0007] Based on this, the present application is proposed. SUMMARY

[0008] The present application provides a kind of cuttable aramid laminated gasket and its preparation method to solve the problems existing in the prior art, and the specific technical solutions are as follows:

[0009] A kind of cuttable aramid laminated gasket, comprising the following components by mass:

[0010]

[0011] As an improvement of the above technical solution, the benzoxazine resin is selected from one or more of bisphenol A type benzoxazine resin, bisphenol F type benzoxazine resin, phenol / diamino diphenyl methane type benzoxazine resin.

[0012] As an improvement of the above technical solution, the epoxy resin is selected from one or more of liquid glycidyl ether type epoxy resin, liquid glycidyl ester type epoxy resin, liquid glycidyl amine type epoxy resin, phenolic modified epoxy resin, bisphenol A epoxy resin.

[0013] As an improvement of the above technical solution, the curing agent is selected from one or more of alicyclic amine, aliphatic amine, 4,4-diamino benzene sulfone, imidazole.

[0014] As an improvement of the above technical solution, the solvent is selected from one or two of ethylene glycol monomethyl ether, propylene glycol monomethyl ether, N,N-dimethylformamide.

[0015] As an improvement of the above technical solution, the flame retardant is selected from one or more of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), [(6-oxo-(6H)-dibenz-(CE)(1,2)-oxaphosphorin-6-keto) methyl]-succinic acid (DOPO-ITA, DDP), ammonium polyphosphate, hexaphenoxy cyclotriphosphazene.

[0016] As an improvement of the above technical solution, the accelerator is one or more of boron trifluoride ethylamine, 2-methylimidazole, organic urea.

[0017] A preparation method of a cuttable aramid laminated gasket, comprising the following steps:

[0018] Step one, configuration of the adhesive

[0019] The curing agent is dissolved in a part of the solvent to form a curing agent solution, then the benzoxazine resin and the epoxy resin are placed in a reaction kettle, heated to 100-130℃ until the resin is completely melted, the stirring is started, the cooling water is supplied to the reaction kettle to reduce the temperature to 60℃, a part of the solvent is added in several times, the curing agent solution is added into the reaction kettle when the temperature is reduced to below 40℃, and the flame retardant and graphite are added after the adhesive is fully stirred and uniform, then the remaining solvent is diluted to a solid content of 60-65wt%, to obtain the adhesive; the adhesive is transferred to the glue tank for standby;

[0020] Step two, gluing on the substrate

[0021] The reinforcing material is immersed in the paint tank containing the adhesive, and then enters the oven after gluing, and forms a semi-cured sheet after drying;

[0022] Step three, hot press forming

[0023] The prepreg is layered, and then the layered prepreg is transferred to an oil press for hot pressing. The pressing process is as follows: preheating to 150 DEG C, pressurizing to 1 MPa, holding for 30 min, then increasing the temperature to 180 DEG C, while starting gradient pressurization, finally pressurizing to 8 MPa, holding for 2 h, then increasing the temperature to 200 DEG C, holding for 1 h, then water cooling, cooling to below 60 DEG C, unloading, and after inspection, edge removal and packaging, the punchable and shearable aramid laminated gasket is obtained.

[0024] As an improvement of the above technical solution, the reinforcing material is one or more of aramid fiber felt and aramid fiber fabric;

[0025] When the reinforcing material is aramid fiber felt, the corresponding prepreg is marked as prepreg one;

[0026] When the reinforcing material is aramid fiber fabric, the corresponding prepreg is marked as prepreg two;

[0027] The prepreg one and the prepreg two are layered in three ways, which are as follows:

[0028] The first way is to stack and layer the prepreg one and the prepreg two in a symmetrical structure, that is, 1 piece of prepreg one and 1 piece of prepreg two are layered alternately, and finally the prepreg two is used as the surface;

[0029] The third way is to stack and layer 1 piece of prepreg two and 3 pieces of prepreg one in a symmetrical structure, that is, 1 piece of prepreg two and 3 pieces of prepreg one are layered alternately, and finally the prepreg two is used as the surface;

[0030] The second way is to stack and layer 1 piece of prepreg two and 2 pieces of prepreg one, that is, 1 piece of prepreg two and 2 pieces of prepreg one are layered alternately, and finally 1 piece of prepreg two is used as the surface.

[0031] As an improvement of the above technical solution, in step two, the glue amount is controlled to be 48-52 wt% of the total weight of the prepreg, and the flow degree is 13-15 wt%; the oven is divided into three sections, that is, a preheating zone, a high temperature zone and a low temperature zone, wherein the preheating zone is set to 135-145 DEG C, the high temperature zone is set to 145-155 DEG C, and the low temperature zone is set to 140-150 DEG C;

[0032] In step three, the gradient pressurization process is as follows: pressurizing from 1 MPa to 6 MPa at a rate of 0.5 MPa / 2 DEG C while increasing the temperature from 150 DEG C to 170 DEG C, and pressurizing from 6 MPa to 8 MPa at a rate of 0.2 MPa / 1 DEG C while increasing the temperature from 170 DEG C to 180 DEG C.

[0033] The aramid fiber fabric of the present application is para-aramid (poly-para-phenyleneterephthalamide) (PPTA), such as or and the like; the present application preferably uses KEVLAR 29 or KEVLAR 49 fiber fabric produced by DuPont.

[0034] The adhesive of the present application is a compound system of benzoxazine resin and epoxy resin. The benzoxazine resin is preferably bisphenol A type benzoxazine resin, and the epoxy resin is preferably epoxy resin E44. The curing agent is preferably 4,4-diamino diphenyl sulfone (DDS), and the accelerator is preferably 2-methyl imidazole. The adhesive of the present application has a solid content of 65±1.5wt%, and a viscosity of 100-500mPa·s.

[0035] In the hot pressing process, if the rate of gradient pressure is too high or too low, it will affect the flowability of the resin inside the laminate, greatly affect the construction of the crosslinked network, and finally affect the mechanical properties and punch shearability.

[0036] Compared with graphite, if molybdenum disulfide, carbon black, nano-silica, etc. are used as reinforcing materials in the adhesive, the final samples are found to have burrs and burrs after punch shear processing, and the punch shearability is very poor.

[0037] The present application has the following advantages:

[0038] The present application uses a mixed system of bisphenol A type benzoxazine resin and bisphenol A epoxy resin as the adhesive, which greatly improves the flame retardant performance while ensuring the bonding strength. Further, the use of polyammonium phosphate as an additional flame retardant can achieve UL-94 V-0 level flame retardation when the addition amount is not higher than 10% (the ratio of the total mass of the flame retardant and the resin). At the same time, in order to improve the punch shearability of the aramid laminate gasket, graphite is used as a filler in the adhesive, and aramid fiber felt and aramid fiber fabric are used in a specific ratio. The use of a specific pressing process, aramid fiber felt as internal support, improves the shear stress of the punch shear blade on the aramid plain fabric, and the obtained sample has no burrs and burrs after punch shear processing, realizing the convenient punch shear processing of the aramid laminate gasket. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 Schematic diagram of the semi-cured sheet stacking layer in Example 3 and Example 7;

[0040] Figure 2 Schematic diagram of the semi-cured sheet stacking layer in Example 4 and Example 8;

[0041] Figure 3Figure showing the layup of prepreg for Example 5, Example 9;

[0042] Figure 4 Figure showing the layup of prepreg for Example 5, Example 9;

[0043] Figure 5 Figure showing the layup of prepreg for Example 5, Example 9;

[0044] Figure 6 Figure showing the layup of prepreg for Example 5, Example 9;

[0045] Figure 7 Figure showing the layup of prepreg for Example 5, Example 9. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0047] Example 1

[0048] 1. Preparation of adhesive

[0049] Phenolic epoxy resin 638S 100 kg was placed in a reaction kettle and heated to 110°C, vacuumized for 30 min, after completely melted, the stirring was started (600 r / min), and bisphenol A epoxy resin (E51) 45 kg was added, after the temperature was stable, DDS 40 kg was added in 4 times, after the addition was completed, the reaction was carried out for 35 min, after the solution was clear and transparent, water was passed to cool to below 70°C, solvent (ethylene glycol monomethyl ether) 40 kg was added, and ammonium polyphosphate 10 kg, boron trifluoride ethylamine solution (boron trifluoride ethylamine was dissolved in solvent to prepare a solution with a mass fraction of 30%) were added in sequence, after stirring uniformly, the adhesive was obtained, the solid content of the adhesive was determined, and the solid content of the adhesive was controlled to 60±1 wt% with ethylene glycol monomethyl ether as the solvent, and the curing time was 180±5 s.

[0050] 2. Gluing on substrate

[0051] The areal density of the aramid fiber felt was 52 g / m 2 , and the width was customized to 1200 mm. The aramid fiber felt was pulled by a belt, passed through a front beam roller in sequence, immersed in a paint tank containing the adhesive, and after the adhesive was controlled by a roller, it was entered into a partitioned oven, dried to form prepreg A, and cut according to requirements. In this embodiment, the prepreg was cut to 1200 mm*1050 mm. The gluing speed was set to 5 m / min. The roller was used to control the amount of adhesive, and the amount of adhesive was controlled to 48-52 wt% of the total weight, i.e. the outfeed areal density was 100.0-108.3 g / m 2The oven is divided into three sections, i.e., a preheating zone, a high-temperature zone, and a low-temperature zone, wherein the furnace temperature of the preheating zone is set to 135°C, the high-temperature zone is set to 145°C, and the low-temperature zone is set to 140°C. The length of each section of the oven is 3 m, and the total length is 9 m.

[0052] 3. Hot press forming

[0053] The prepreg A is layered, and the thickness of each layer of the prepreg A after pressing is 0.05 mm. Each 30 prepregs is one plate, and the high-gloss steel plates are clamped on both sides. The steel plates between every two adjacent plates are separated by 10 pieces of pad paper. Then the layered prepreg A is transferred to a 1500-ton oil press. The pressing process is as follows: preheating to 120°C, pressurizing to 5 MPa, and holding for 30 min. Then the temperature is raised at a rate of 5°C / min, and the gradient pressurization is started at the same time. The temperature is raised to 160°C, the pressure is finally raised to 8 MPa, and the temperature is held for 4 h. Then the water is passed to cool down, and the temperature is lowered to below 60°C. The plate is unloaded, and after inspection, edge removal, and packaging, the sample plate M is obtained. The thickness of the sample plate is 1.50±0.10 mm.

[0054] Example 2

[0055] 1. Preparation of adhesive

[0056] The phenolic epoxy resin 638S 100 kg is placed in a reaction kettle and heated to 110°C. After vacuumizing for 30 min, the stirring (600 r / min) is started after the resin is completely melted. Then 45 kg of bisphenol A epoxy resin (E51) is added. After the temperature is stabilized, 40 kg of DDS is added in four portions. After the addition is completed, the solution is reacted for 35 min. After the solution is clear and transparent, the water is passed to cool down to below 70°C. Then 40 kg of solvent (ethylene glycol monomethyl ether) is added, followed by 10 kg of ammonium polyphosphate and 10 kg of boron trifluoride ethylamine solution (boron trifluoride ethylamine is dissolved in the solvent to prepare a solution with a mass fraction of 30%). After the stirring is uniform, the adhesive is obtained. The solid content of the adhesive is measured, and the solid content of the adhesive is controlled to 60±1 wt% by using ethylene glycol monomethyl ether as the solvent. The curing time is 180±5 s.

[0057] 2. Gluing of the substrate

[0058] The areal density of the aramid fiber fabric is 160 g / m 2 , and the width is customized to 1200 mm. The aramid fiber felt is pulled through the front beam roller, immersed in the paint tank containing the adhesive, and then controlled by the roller to control the amount of adhesive. After drying in the partition oven, the prepreg B is formed, and cutting is performed according to the requirements. In this embodiment, the prepreg is cut to 1200 mm*1050 mm. The gluing speed is set to 3 m / min. The amount of adhesive is controlled by the roller, and the amount of adhesive is controlled to be 48-52 wt% of the total weight, i.e., the out-of-material areal density is 307.7-333.3 g / m2 The fluidity is 13-15 wt%. The oven is divided into three sections: a preheating zone, a high-temperature zone, and a low-temperature zone. The oven temperature in the preheating zone is set at 135℃, the high-temperature zone at 145℃, and the low-temperature zone at 140℃. Each section of the oven is 3m long, for a total of 9m.

[0059] 3. Hot pressing

[0060] Prepreg B is laid up in layers, with each layer of prepreg B having a thickness of 0.1mm after pressing. Every 15 prepregs form one board, sandwiched between two high-gloss steel plates. Ten sheets of paper separate the steel plates between each adjacent board. The laid-up prepreg A is then transferred to a 1500-ton hydraulic press. The pressing process is as follows: preheating to 120℃, pressurizing to 5MPa, holding at that temperature for 30 minutes, then increasing the temperature at a rate of 5℃ / min while simultaneously applying gradient pressurization, raising the temperature to 160℃, finally reaching a pressure of 8MPa, and holding at that temperature for 4 hours. Then, water is used to cool the board down to below 60℃. The board is then removed, inspected, trimmed, and packaged to obtain sample N. The sample thickness is 1.50±0.10mm.

[0061] Example 3

[0062] Semicured sheet A was obtained according to Example 1, and semicured sheet B was obtained according to Example 2.

[0063] Prepreg A and prepreg B are stacked and laid in a symmetrical structure (according to...). Figure 1 Method), that is, after laying one semi-cured sheet A and one semi-cured sheet B alternately, the following is used: Figure 1 The prepregs are symmetrically laid up, with prepreg B as the face and high-gloss steel plates on both sides. Ten prepregs A and ten prepregs B are hot-pressed using the pressing process described in Example 1 or Example 2 to obtain sample O. The sample thickness is 1.5mm ± 0.10mm.

[0064] Example 4

[0065] Semicured sheet A was obtained according to Example 1, and semicured sheet B was obtained according to Example 2.

[0066] Lay out layers of 1 prepreg B and 2 prepregs A (according to...). Figure 2 (Method), that is, one semi-cured sheet B and two semi-cured sheets A are laid alternately, using the following method. Figure 2 The layers are stacked sequentially, with a prepreg B as the final surface, sandwiched between high-gloss steel plates on both sides. Ten layers of padding paper separate the steel plates between two adjacent samples. According to... Figure 2The prepreg A is 14 sheets and the prepreg B is 8 sheets. After hot pressing by the pressing process of Example 1 or Example 2, the sample plate P is obtained. The thickness of the sample plate is 1.5 mm ± 0.10 mm.

[0067] Example 5

[0068] The prepreg A is obtained according to the manner of Example 1 and the prepreg B is obtained according to the manner of Example 2.

[0069] The prepreg B is 1 sheet and the prepreg A is 3 sheets. The prepreg is stacked in a symmetrical structure (according to the manner of the attached drawing) and is hot pressed by the pressing process of Example 1 or Example 2. The sample plate R is obtained. Figure 3 The prepreg B is 1 sheet and the prepreg A is 3 sheets. The prepreg is stacked in a symmetrical structure (according to the manner of the attached drawing) and is hot pressed by the pressing process of Example 1 or Example 2. The sample plate R is obtained. Figure 3 The prepreg B is 1 sheet and the prepreg A is 3 sheets. The prepreg is stacked in a symmetrical structure (according to the manner of the attached drawing) and is hot pressed by the pressing process of Example 1 or Example 2. The sample plate R is obtained. Figure 3 The prepreg B is 6 sheets and the prepreg A is 18 sheets. After hot pressing by the pressing process of Example 1 or Example 2, the sample plate Q is obtained. The thickness of the sample plate is 1.5 mm ± 0.10 mm.

[0070] Example 6

[0071] 1. Preparation of the adhesive

[0072] 100 kg of solid bisphenol A benzoxazine resin and 10 kg of epoxy resin E44 are placed in a reaction kettle and heated to 120°C. After complete melting, stirring is started and 40 kg of DDS is added in four portions. After the addition is completed, the reaction is continued for 35 min and the temperature is lowered to 60°C by cooling water. Then 40 kg of solvent (propylene glycol monomethyl ether) is added in three portions. When the temperature is lowered to below 40°C, 0.8 kg of 2-methylimidazole solution (2-methylimidazole is dissolved in solvent to prepare a solution with a mass fraction of 10%) is added to the reaction kettle and stirred uniformly. Then 10 kg of ammonium polyphosphate and 5 kg of graphite (average particle size 500 nm) are added. The solvent (propylene glycol monomethyl ether) is added to dilute the mixture to a solid content of 65 ± 1 wt% and the adhesive is obtained. The adhesive is transferred to an adhesive tank for use.

[0073] 2. Adhesion of the substrate

[0074] The areal density of the aramid fiber felt is 52 g / m 2, the width is customized as 1200 mm. The aramid fiber felt is pulled by a belt, sequentially passes through a front beam roller, is immersed into a paint tank containing adhesive, is controlled by a roller, enters a partition oven, and is dried to form a prepreg C. The prepreg C is cut according to requirements. In this embodiment, the prepreg C is cut into 1200 mm*1050 mm. The speed of the gluing vehicle is set as 5 m / min. The adhesive amount is controlled by a roller, and the adhesive amount is controlled as 48-52 wt% of the total weight, that is, the surface density of the output is 100.0-108.3 g / m 2 , and the flow degree is 13-15 wt%. The oven is divided into three sections, that is, a preheating section, a high-temperature section, and a low-temperature section. The preheating section is set as 145 ℃, the high-temperature section is set as 155 ℃, and the low-temperature section is set as 150 ℃. The length of each section is 3 m, and the total length is 9 m.

[0075] 3. Hot pressing

[0076] The prepreg C is laminated. According to the calculation of the thickness of each layer of prepreg C after pressing, that is, 0.05 mm, every 30 prepregs is one plate. The two sides are clamped by high-gloss steel plates. The steel plates between every two adjacent plates are separated by 10 pieces of pad paper. Then, the laminated prepreg A is transferred to a 1500-ton oil press. The pressing process is as follows: preheating to 150 ℃, pressurizing to 1 MPa, and holding for 30 min, then heating to 180 ℃ while starting gradient pressurizing, and finally pressurizing to 8 MPa. Specifically, pressurizing from 1 MPa to 6 MPa at a rate of 0.5 MPa / 2 ℃ while the temperature rises from 150 ℃ to 170 ℃, and pressurizing from 6 MPa to 8 MPa at a rate of 0.2 MPa / 1 ℃ while the temperature rises from 170 ℃ to 180 ℃. Holding for 2 h, then heating to 200 ℃, holding for 1 h, then cooling by cooling water to below 60 ℃, unloading the plate, and obtaining the sample plate R after inspection, edge removal, and packaging. The thickness of the sample plate is 1.50±0.10 mm.

[0077] Example 7

[0078] 1. Preparation of adhesive

[0079] 100 kg of solid bisphenol A type benzoxazine resin and 10 kg of epoxy resin E44 are placed in a reaction kettle, heated to 120 ℃, and after complete melting, stirring is started. 40 kg of DDS is added in four portions. After the addition is completed, the reaction is carried out for 35 min, and the temperature is lowered to 60 ℃ by cooling water. 40 kg of solvent (propylene glycol monomethyl ether) is added in three portions. When the temperature is lowered to below 40 ℃, 0.8 kg of 2-methylimidazole solution (2-methylimidazole is dissolved in solvent to prepare a solution with a mass fraction of 10%) is added to the reaction kettle, and after uniform stirring, 10 kg of ammonium polyphosphate is added. After adding 5 kg of graphite (average particle size 500 nm), the solvent (propylene glycol monomethyl ether) is diluted to a solid content of 65±1 wt% to obtain the adhesive, which is transferred to a glue tank for standby.

[0080] 2. Gluing of the substrate

[0081] The areal density of the aramid fiber fabric was 160 g / m 2 , and the width was customized to 1200 mm. Using belt traction, the aramid fiber mat was sequentially passed through a front beam roller, immersed in a paint tank containing adhesive, and then passed through a roller to control the adhesive, and then entered a partitioned oven to dry to form a prepreg D, and was cut according to requirements. In this example, the prepreg was cut to 1200 mm * 1050 mm. The gluing speed was set to 3 m / min. The amount of adhesive was controlled by using a roller, and the amount of adhesive was controlled to be 48-52 wt% of the total weight, i.e. the outfeed areal density was 308-333 g / m 2 , and the flow was 13-15 wt%. The oven was divided into three sections, i.e. a preheating zone, a high temperature zone and a low temperature zone, wherein the preheating zone was set to 145°C, the high temperature zone was 155°C, and the low temperature zone was 150°C, and the length of each section of the oven was 3 m, for a total of 9 m.

[0082] 3. Hot pressing

[0083] The prepreg C in Example 6 was taken, and according to the calculation of the thickness of each layer of prepreg D after pressing, the prepreg C and the prepreg D were stacked and laid in a Figure 1 symmetrical structure, 10 pieces of prepreg C and 10 pieces of prepreg D for one plate, with isolation film on both sides and high-gloss steel plate clamping, and 10 pieces of paper were placed between the steel plates of every two adjacent plates. Then the laid prepreg was transferred to a 1500 ton oil press. The pressing process was as follows: preheating to 150°C, pressurizing to 1 MPa, holding for 30 min, then heating to 180°C while starting gradient pressurizing, and finally pressurizing to 8 MPa; specifically: pressurizing from 1 MPa to 6 MPa at a rate of 0.5 MPa / 2°C while the temperature rises from 150°C to 170°C, and pressurizing from 6 MPa to 8 MPa at a rate of 0.2 MPa / 1°C while the temperature rises from 170°C to 180°C. Holding for 2 h, then heating to 200°C, holding for 1 h, then cooling with cooling water to below 60°C, unloading the plate, and after inspection, edge removal and packaging, the sample plate S was obtained. The thickness of the sample plate was 1.50 ± 0.10 mm.

[0084] Example 8

[0085] The prepreg C was obtained in the manner of Example 6, and the prepreg D was obtained in the manner of Example 7.

[0086] According to the stacking and laying of 1 piece of prepreg D and 2 pieces of prepreg C (in the manner of Figure 2 ), i.e. 1 piece of prepreg D and 2 pieces of prepreg C were laid alternately, and the Figure 2The prepregs are stacked in layers in turn, finally with one prepreg D as the surface, and the two sides are clamped with high-gloss steel plates, and the steel plates between two adjacent sample plates are separated by 10 layers of pad paper. According to the method of Figure 2 The prepregs are stacked in layers in turn, finally with one prepreg D as the surface, and the two sides are clamped with high-gloss steel plates, and the steel plates between two adjacent sample plates are separated by 10 layers of pad paper. According to the method of

[0087] Example 9

[0088] The prepregs C are obtained according to the method of Example 6, and the prepregs D are obtained according to the method of Example 7.

[0089] According to the method of 1 prepreg D and 3 prepregs C are stacked in layers in a symmetrical structure (according to the method of Figure 3 The prepregs are stacked in layers in turn, finally with one prepreg D as the surface, and the two sides are clamped with high-gloss steel plates, and the steel plates between two adjacent sample plates are separated by 10 layers of pad paper. According to the method of Figure 3 The prepregs are stacked in layers in turn, finally with one prepreg D as the surface, and the two sides are clamped with high-gloss steel plates, and the steel plates between two adjacent sample plates are separated by 10 layers of pad paper. According to the method of Figure 3 The prepregs are stacked in layers in turn, finally with one prepreg D as the surface, and the two sides are clamped with high-gloss steel plates, and the steel plates between two adjacent sample plates are separated by 10 layers of pad paper. According to the method of

[0090] Test method

[0091] The punching shear and related properties of the sample plates M to U are tested, and the test results are shown in Tables 1 and 2:

[0092] Table 1

[0093]

[0094]

[0095] Table 2

[0096]

[0097] From Tables 1 and 2, it can be seen that the comprehensive performance of the sample plate U is the best, which can have excellent punching shear, no burr, high parallel layer impact strength, high heat distortion temperature under load, and high mechanical properties.

[0098] In the above embodiment, the punchable aramid laminated gasket of the present application has simple preparation method and excellent performance, and can be used as important components such as V-shaped ring, angle ring, gap gasket, etc. in devices such as motor, transformer, rail transit, etc. The present application stacks aramid fiber fabric and aramid fiber felt, adopts specific stacking process, and uses aramid fiber felt as physical support between aramid fabric layers, which shows excellent punch performance and realizes punchability of aramid composite material. Meanwhile, mechanical properties (including tensile strength, bending strength, wear resistance, etc.) are also improved.

[0099] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of making a punchable aramid laminate gasket, characterized by, Comprising the following steps: Step one, configuration of the adhesive Take 100 kg of solid bisphenol A type benzoxazine resin, 10 kg of epoxy resin E44, place it in a reaction kettle, heat to 120°C, wait for it to melt completely, then start stirring, add 4, 4-diamino benzene sulfone 40 kg in 4 times, after adding, react for 35 min, and cool to 60°C with cooling water, add propylene glycol monomethyl ether 40 kg in three times, when the temperature drops below 40°C, add 0.8 kg of 2-methyl imidazole solution to the reaction kettle, the 2-methyl imidazole solution is prepared by dissolving 2-methyl imidazole in a solvent to form a solution with a mass fraction of 10%; After stirring evenly, add ammonium polyphosphate 10 kg, then add graphite with an average particle size of 500 nm 5 kg, and then dilute with propylene glycol monomethyl ether to a solid content of 65±1wt%, to obtain an adhesive, which is transferred to a glue tank for standby; Step two, gluing on the substrate Immerse the reinforcing material in the paint tank containing the adhesive, and after gluing, enter the oven for drying to form a prepreg; Step three, hot pressing Lay the prepreg, then transfer the laid prepreg to an oil press for hot pressing, the pressing process is as follows: preheat to 150°C, press to 1MPa, and keep for 30 min, then heat to 180°C, while starting gradient pressing, finally press to 8MPa, keep for 2h, then heat to 200°C, keep for 1h, then cool down by water, cool down to below 60°C, unload the plate, and after inspection, edge removal and packaging, the punchable aramid laminated gasket is obtained; When the reinforcing material is aramid fiber felt, the corresponding prepreg is marked as prepreg one; When the reinforcing material is aramid fiber fabric, the corresponding prepreg is marked as prepreg two; According to the stacking of 1 prepreg two and 3 prepregs one in a symmetrical structure, i.e. 1 prepreg two, 3 prepregs one are laid with an interval, and finally the prepreg two is used as the surface.

2. The method of claim 1, wherein the method further comprises: In step two, the amount of glue is controlled to be 48-52wt% of the total weight of the prepreg, and the flow degree is 13-15wt%; The oven is divided into three sections, i.e. preheating zone, high temperature zone and low temperature zone, among which the preheating zone is set to 135~145°C, the high temperature zone is 145~155°C, and the low temperature zone is 140~150°C; In step three, the gradient pressing process is: press from 1MPa to 6MPa at a rate of 0.5MPa / 2°C while the temperature rises from 150°C to 170°C, and press from 6MPa to 8MPa at a rate of 0.2MPa / 1°C while the temperature rises from 170°C to 180°C.

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