Preparation method of nylon 6 composite material

Abstract

The invention provides a method for preparing a composite material from continuous fiber, namely glass fiber cloth reinforced nylon 6, which comprises the following steps: heating and melting caprolactam, and adding a catalyst and an activating agent to obtain a prepolymer for preparing nylon 6; spraying a KH-550 solution to the surface of the glass fiber cloth, and drying; drawing the glass fiber cloth to enable the glass fiber cloth to be preheated to 100-130 DEG C in the process of being drawn to move, then spraying the prepolymerized material on the two surfaces of the glass fiber cloth, and drawing the glass fiber cloth to pass through an inert atmosphere protection environment at 130-200 DEG C to obtain the glass fiber cloth. The prepolymer is subjected to anionic polymerization on the surface, gaps and the like of the glass fiber cloth, so that all-directional coating of nylon 6 on the continuous glass fiber cloth is realized, and the continuous fiber, namely the glass fiber cloth reinforced nylon 6 high-performance composite material is prepared.

Description

Technical Field

[0001] The invention belongs to the field of high-performance polymer-based composite materials, and in particular relates to a preparation method of a nylon 6 composite material reinforced by glass fiber cloth. Background Art

[0002] With the establishment of energy conservation and emission reduction targets and the further popularization of environmental protection concepts, the requirements for energy conservation and emission reduction in industrial production are becoming increasingly higher. Lightweighting of parts while meeting the performance requirements is one of the important ways to achieve energy conservation and emission reduction. An important aspect of lightweighting of parts is the lightweighting of materials. Polymer-based composite materials are one of the important ways to achieve lightweight materials.

[0003] Since thermosetting resin composite materials have the problems of low fracture toughness, easy damage, poor environmental applicability and difficulty in recycling, there is also the problem of long production cycle. These problems limit the application of thermosetting resin composite materials. Therefore, thermoplastic resin-based composite materials have been rapidly developed in recent years. Among them, continuous glass fiber reinforced nylon 6 composite materials have attracted great attention from the industry due to their excellent tensile strength, high impact resistance and recyclability. The prepared composite materials have broad application prospects in the fields of automobiles, rail transportation, national defense, aerospace, etc.

[0004] Chinese patents with publication numbers CN107033589A, CN101152747A, CN103042742A and CN104910374A disclose methods for preparing continuous fiber reinforced nylon 6 composite materials by using caprolactam as a monomer, anionic ring-opening polymerization, and resin transfer molding (RTM) molding process. Chinese patent with publication number CN102922751A discloses a glue injection machine for producing continuous fiber reinforced nylon 6 composite materials by RTM method.

[0005] However, none of the above methods for producing fiber-reinforced nylon 6 composite materials can achieve in-situ compounding on nylon 6 glass fiber cloth and continuous production of glass fiber cloth-reinforced nylon 6 composite materials. Summary of the invention

[0006] The object of the present invention is to provide a method for efficiently and continuously preparing a glass fiber cloth reinforced nylon 6 composite material.

[0007] The present invention is achieved through the following technical solutions: A continuous preparation method of a continuous glass fiber reinforced nylon 6 composite material comprises the following steps: After heating and melting caprolactam, a catalyst and an activator are added to obtain a nylon 6 prepolymer; Spray the KH-550 solution onto the surface of the glass fiber cloth and then dry it; The glass fiber cloth is pulled so that the glass fiber cloth is preheated to 100-130° C. during the pulling and moving process, and then the nylon 6 prepolymer is sprayed on both sides of the glass fiber cloth. The glass fiber cloth is then pulled through an inert other protective atmosphere environment at 130-200° C. to cause the nylon 6 prepolymer to undergo anionic polymerization on the surface and gaps of the glass fiber cloth, thereby realizing in-situ composite preparation of continuous glass fiber cloth reinforced nylon 6 composite materials.

[0008] The continuous preparation method of the continuous glass fiber reinforced nylon 6 composite material also includes the step of further spraying a DMF solution of 4-carboxyphenylacetonitrile and DCC on the surface of the glass fiber cloth sprayed with KH-550.

[0009] The amount of the catalyst added is 0.0597 to 5.97 wt % of the amount of caprolactam used.

[0010] The catalyst includes sodium methoxide, sodium hydroxide, potassium hydroxide, sodium caprolactam, metallic sodium or metallic potassium.

[0011] The activator includes at least one of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene diisocyanate or diphenylmethane diisocyanate.

[0012] The molar ratio of the activator to the catalyst is 0.95-1.05:1.

[0013] The spraying amount of the nylon 6 raw material is 20 to 50 parts by weight of nylon 6 raw material for every 50 to 80 parts by weight of the glass fiber cloth on both sides.

[0014] The concentration of the KH550 solution is 0.1-1.5 wt %.

[0015] The glass fiber cloth includes plain glass fiber cloth, twill glass fiber cloth, satin glass fiber cloth, rib glass fiber cloth or basket glass fiber cloth.

[0016] The melting temperature is 70-120°C.

[0017] The glass fiber cloth passes through a protective atmosphere of 130-200° C. for 2 to 30 minutes; The protective atmosphere includes nitrogen, helium or argon.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The method provided by the present invention can better solve the technical problem of compatibility of two-phase interfaces. Polymer-based composite materials are materials obtained by combining fibers and matrix into a whole. In this material, due to the existence of the interface, the roles played by the fibers and the matrix are independent and interdependent. In order to better exert the comprehensive performance of the composite material, the reinforcement and the matrix resin must form a good interface effect, among which compatibility is one of the important factors. Due to the poor compatibility between glass fiber cloth and nylon 6, it is difficult to form a good bond in their interface layer, thereby affecting the comprehensive performance of the material system. The method provided by the present invention utilizes the principle of similar compatibility and uses KH550 to pretreat the surface of the glass fiber cloth so that the surface carries a certain amount of -NH2, which reduces the surface energy of the glass fiber cloth and changes the size of the surface tension of the glass fiber cloth. On the one hand, it significantly improves the wetting effect and dispersion uniformity of the reaction precursor on the glass fiber cloth, and on the other hand, it improves the compatibility and bonding force between the matrix nylon 6 and the surface of the glass fiber cloth.

[0019] 2. The method provided by the present invention ideally solves the key core technical problem of uniform dispersion of reinforcement (continuous glass fiber cloth) and matrix (nylon 6). It is well known that in the preparation process of composite materials, uniform dispersion of reinforcement in the matrix is ​​a key factor in improving performance, and vice versa. For polymer-based composite materials, the wettability or ability of resin to fiber is an important factor in whether the resin can be evenly distributed around the fiber, and it is also an important factor in producing good adhesion at the interface between resin and fiber. In the present invention, the monomer caprolactam (whose melting point is 68-71°C), initiator, activator, etc. are mixed evenly after preliminary treatment and exist in a liquid state. In the low temperature section, a pressurized spraying equipment can be used to spray it on the front and back sides of the glass fiber cloth. Since the viscosity of the monomer is extremely low and the fluidity is good after it is melted, it can fully penetrate the small holes, gaps and surfaces of the glass fiber cloth. The impregnated glass fiber cloth is further heated in the subsequent heating box. These similar reaction precursors undergo ring-opening polymerization in the heating box section. After the reaction is completed, the nylon 6 is fully coated on the glass fiber cloth in situ, and the fibers are bonded into a whole, so that the individual fibers can carry the load together and give full play to the characteristics of the reinforced material. In other words, the matrix nylon 6 is evenly dispersed in the reinforcement (continuous glass fiber cloth), that is, the continuous glass fiber cloth is evenly dispersed in the nylon 6, which ideally solves the dispersion uniformity of the two.

[0020] 3. The method provided by the present invention adopts in-situ composite technology to prepare continuous fiber cloth reinforced nylon 6 composite sheet, which can not only ensure the uniformity of product quality, but also realize large-scale and intelligent production.

[0021] 4. The comprehensive mechanical properties of the composite material prepared by the method provided by the present invention are better than those of the glass fiber cloth composite material prepared by commercial PA6. The molecular weight of ordinary nylon 6 is generally around 30,000, and the crystallinity is less than 40%; the molecular weight of nylon 6 prepared by introducing benzonitrile on the surface of glass fiber cloth in certain embodiments of the present invention is 70,000 to 100,000, and the crystallinity can exceed 50%. This is because the introduction of benzonitrile activates the anionic polymerization reaction in situ and increases the molecular weight of nylon 6. Moreover, the introduction of benzonitrile also improves the regularity of nylon 6 molecules, thereby obtaining nylon 6 with high crystallinity. Therefore, whether in terms of strength, stiffness, wear resistance and chemical resistance, the performance of the composite material prepared by the present invention is superior to that of the glass fiber cloth composite material prepared by commercial PA6.

[0022] 5. Since the method provided by the present invention adopts anionic polymerization method to obtain composite nylon 6 on the surface of glass fiber, the method provided by the present invention can control the molecular chain structure and molecular weight of nylon 6 by adjusting the type and amount of activator in the process of preparing the composite material, thereby achieving the designability of product performance and being suitable for different use environments.

[0023] 6. The composite material prepared by the method provided by the present invention uses fiber cloth as the skeleton of the composite material. The prepared composite material has high strength, high modulus, and high impact resistance, and is an ideal metal replacement material.

[0024] 7. The method provided by the present invention can prepare the sheet product from monomers in one go, which significantly reduces the manufacturing cost. In the prior art, when preparing continuous fiber cloth reinforced nylon composite materials, the method usually adopted is to evenly spread the industrial finished nylon resin on the surface of the glass fiber cloth, and then compact it and heat it in a heating box to melt the nylon resin, and then cool it, calender it, solidify it, cool it, and roll it up to finally prepare the fiber cloth reinforced nylon composite material. The method provided by the present invention directly starts from monomers, integrates the synthesis of nylon 6 with the continuous fiber cloth reinforced composite sheet forming process, and thus can significantly reduce the manufacturing cost of the composite sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram showing a method for preparing a nylon 6 composite material provided by the present invention is shown; Figure 2 The infrared spectrum of the nylon 6 composite material prepared in Example 1 is shown; Figure 3 A photograph of the nylon 6 composite material prepared in Example 1 is shown; Figure 4 A photograph of the nylon 6 composite material prepared in Example 1 is shown; Figure 5A photograph of the nylon 6 composite material prepared in Example 1 is shown. DETAILED DESCRIPTION

[0026] Embodiment 1: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 0.0597% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is hexamethylene diisocyanate (HDI), and the dosage is activator: catalyst = 0.95:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 100°C; the temperature of tank D is controlled at 110°C.

[0027] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use industrial pure alcohol solution with a concentration of 0.1% KH-550 as surface treatment agent, use spray equipment to spray it (the spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, dry it at 70℃ and set aside.

[0028] (2) The treated glass fiber cloth is loaded into the unwinder, and the guide roller, heating box, post-drawing guide roller and winder are turned on. After the fiber cloth roll is drawn and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (in this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth impregnate the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and form an overall impregnation and coating of the continuous fiber cloth), and sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (HDI) to form nylon 6, thereby forming an overall coating of the glass fiber cloth by nylon 6 in situ, and the in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained through cooling calendering, curing, air cooling and winding.

[0029] (3) The process described: the preheating temperature of the glass fiber cloth is 100°C, the heating box is protected by nitrogen, the temperature is 140°C, the heating time is 30 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0030] The molecular weight of nylon 6 prepared in Example 1 is 70,000-80,000, and the crystallinity is 48%.

[0031] Embodiment 2: Formula: Monomer is anhydrous caprolactam (stored in tank A), catalyst is sodium caprolactam (stored in tank B), dosage is 0.1% of caprolactam dosage (mass ratio), activator (stored in tank C) is TDI, dosage is, activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B and C is controlled at 110℃; the temperature of tank D is controlled at 115℃.

[0032] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 0.5% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray 0.5% KH-550 industrial pure alcohol solution (spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, dry it at 75℃ and set aside.

[0033] (2) Load the treated glass fiber cloth into the unwinder, turn on the guide roller, heating box, post-drawing guide roller and winder, and the fiber cloth roll is drawn and preheated by the guide roller, and then enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth impregnates the surface, gaps, fine spaces, etc. of the glass fiber cloth, and forms an overall impregnation and coating of the continuous fiber cloth), and then sent to the heating box, the monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst and TDI to form nylon 6, thereby forming an overall coating of the continuous glass fiber cloth by nylon 6 in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0034] (3) The process described: the preheating temperature of the glass fiber cloth is 110°C, the heating box is protected by nitrogen, the temperature is 150°C, the heating time is 20 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0035] The molecular weight of nylon 6 prepared in Example 2 is 70,000-90,000, and the crystallinity is 46%.

[0036] Embodiment 3: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 0.5% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is MDI, the dosage is, activator: catalyst = 1.05: 1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 100°C; the temperature of tank D is controlled at 115°C.

[0037] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 1% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it (the spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, and then dry it at 80℃ for use.

[0038] (2) The treated glass fiber cloth is loaded into the unwinding machine, and the guide roller, heating box, post-drafting guide roller and winder are turned on. After the fiber cloth roll is stretched and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth impregnate the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and form an overall impregnation and coating of the continuous fiber cloth), and sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst MDI to form nylon 6, thereby forming an overall coating of the continuous glass fiber cloth in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0039] (3) The process described: the preheating temperature of the glass fiber cloth is 120°C, the heating box is protected by nitrogen, the temperature is 160°C, the heating time is 15 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0040] The molecular weight of nylon 6 prepared in Example 3 is 80,000-90,000 and the crystallinity is 50%.

[0041] Embodiment 4: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 1% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is a mixture of TDI and HDI (molar ratio is 1:1), and the dosage is activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 100℃; the temperature of tank D is controlled at 125℃.

[0042] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 1.5% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it (the spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, dry it at 80℃ and set aside.

[0043] (2) The treated glass fiber cloth is loaded into the unwinder, and the guide roller, heating box, post-drafting guide roller and winder are turned on. After the fiber cloth roll is stretched and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth impregnate the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and form an overall impregnation and coating of the continuous fiber cloth), and sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (TDI, HDI) to form nylon 6, thereby forming an overall coating of the continuous glass fiber cloth in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0044] (3) The process described: the preheating temperature of the glass fiber cloth is 125°C, the heating box is protected by nitrogen, the temperature is 170°C, the heating time is 12 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0045] The molecular weight of nylon 6 prepared in Example 4 is 80,000-90,000, and the crystallinity is 49%.

[0046] Embodiment 5: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 1.5% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is a mixture of TDI and MDI (mixing ratio is 1:1 molar ratio), and the dosage is activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 100℃; the temperature of tank D is controlled at 120℃.

[0047] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 0.7% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it (the spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, dry it at 90℃ and set aside.

[0048] (2) The treated glass fiber cloth is loaded into the unwinder, and the guide roller, heating box, post-drafting guide roller and winder are turned on. After the fiber cloth roll is stretched and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth impregnate the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and form an overall impregnation and coating of the continuous glass fiber cloth), and sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (TDI, MDI) to form nylon 6, thereby forming an overall coating of the continuous glass fiber cloth in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0049] (3) The process described: the preheating temperature of the glass fiber cloth is 130°C, the heating box is protected by nitrogen, the temperature is 180°C, the heating time is 10 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0050] The molecular weight of nylon 6 prepared in Example 5 is 90,000 to 100,000, and the crystallinity is 48%.

[0051] Embodiment 6: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 3% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is a mixture of TDI and MDI (mixing ratio is 1:1 molar ratio), and the dosage is activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 105°C; the temperature of tank D is controlled at 120°C.

[0052] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 3% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it on the surface of glass fiber cloth after surface cleaning, dry it at 80℃ and set aside.

[0053] (2) The treated glass fiber cloth is loaded into the unwinding machine, and the guide roller, heating box, post-drafting guide roller and winder are turned on. After the fiber cloth roll is stretched and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth infiltrates the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and forms an overall coating on the fiber cloth), and is sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (TDI, MDI) to form nylon 6, thereby forming an overall coating on the glass fiber cloth in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0054] (3) The process described: the preheating temperature of the glass fiber cloth is 130°C, the heating box is protected by nitrogen, the temperature is 180°C, the heating time is 10 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0055] The molecular weight of nylon 6 prepared in Example 6 is 90,000 to 100,000, and the crystallinity is 49%.

[0056] Embodiment 7: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 5.97% (mass ratio) of the amount of caprolactam, the activator (stored in tank C) is a mixture of TDI, HDI and MDI (mixing ratio is 1:1:1 molar ratio), and the dosage is activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B and C is controlled at 100℃; the temperature of tank D is controlled at 120℃.

[0057] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 3% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it (the spray amount is 0.5% of the weight of glass fiber cloth) onto the surface of glass fiber cloth after surface cleaning, dry it at 80℃ and set aside.

[0058] (2) The treated glass fiber cloth is loaded into the unwinder, and the guide roller, heating box, post-drawing guide roller and winder are turned on. After the fiber cloth roll is drawn and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth infiltrates the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and forms an overall coating on the fiber cloth), and is sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (TDI, HDI and MDI) to form nylon 6, thereby forming an overall coating on the glass fiber cloth in situ, and after cooling, calendering, curing, air cooling and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0059] (3) The process described: the preheating temperature of the glass fiber cloth is 140°C, the heating box is protected by nitrogen, the temperature is 180°C, the heating time is 8 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0060] The molecular weight of nylon 6 prepared in Example 7 is 70,000-80,000, and the crystallinity is 46%.

[0061] Embodiment 8: Formula: The monomer is anhydrous caprolactam (stored in tank A), the catalyst is sodium caprolactam (stored in tank B), the dosage is 3% of the amount of caprolactam (mass ratio), the activator (stored in tank C) is a mixture of TDI and MDI (mixing ratio is 1:1 molar ratio), and the dosage is activator: catalyst = 1:1 (molar ratio). Add the three into tank D according to this ratio, mix well and set aside. Reactor (tank) temperature control: The temperature of tanks A, B, and C is controlled at 105°C; the temperature of tank D is controlled at 120°C.

[0062] The preparation steps of the composite sheet are as follows: (1) Pretreatment of glass fiber cloth: Use acetone as spray agent, use spray equipment to clean the surface of glass fiber cloth, and dry it; use 3% KH-550 industrial pure alcohol solution as surface treatment agent, use spray equipment to spray it (spray amount is 0.5% of the weight of glass fiber cloth) on the surface of glass fiber cloth after surface cleaning, dry it at 80℃, then dissolve 4-carboxybenzyl cyanide and DCC in DMF (the content of 4-carboxybenzyl cyanide is 2%, the content of DCC is 0.5%) and spray it on the surface of glass fiber cloth and keep it at 100℃ for 20h.

[0063] (2) The treated glass fiber cloth is loaded into the unwinding machine, and the guide roller, heating box, post-drafting guide roller and winder are turned on. After the fiber cloth roll is stretched and preheated by the guide roller, it enters the formula metering feeder; after the formula metering device mixes according to the proportion (D tank), it is continuously and evenly sprayed on the upper and lower surfaces of the glass fiber cloth by pressurized spray (spraying) (at this stage, the monomer, catalyst, activator, etc. sprayed on the glass fiber cloth infiltrates the surface, gaps, fine vacancies, etc. of the glass fiber cloth, and forms an overall coating on the fiber cloth), and is sent to the heating box. The monomer caprolactam undergoes anionic polymerization under the joint action of the catalyst sodium caprolactam and the activator (TDI, MDI) to form nylon 6, thereby forming an overall coating on the glass fiber cloth in situ, and after cooling, calendering, curing, air cooling, and winding, an in-situ composite continuous fiber reinforced nylon 6 composite material sheet is obtained.

[0064] (3) The process described: the preheating temperature of the glass fiber cloth is 130°C, the heating box is protected by nitrogen, the temperature is 180°C, the heating time is 10 min, the cooling roller temperature is 60°C, and the air cooling time is 6 min.

[0065] The molecular weight of nylon 6 prepared in Example 8 is 90,000 to 100,000, and the crystallinity is 55%.

[0066] The prepared in-situ composite continuous fiber reinforced nylon 6 composite sheet and the plate made by compression molding were subjected to performance testing. The specific test results are shown in the following table.

[0067] Table 1 Mechanical properties test results Density (g / cm3) 0° tensile strength (MPa) 90° tensile strength (MPa) 0° flexural modulus (MPa) 90° flexural modulus (GPa) Example 1 1.70 485 470 21500 22.5 Example 2 1.72 490 480 22100 21.5 Example 3 1.79 500 490 23000 23.5 Example 4 1.73 489 485 22600 22.5 Example 5 1.59 420 390 21000 20 Example 6 1.68 450 420 22140 21.7 Example 7 1.71 475 472 21600 22.0 Example 8 1.82 510 505 23500 24.5 Table 2 Mechanical properties test results 0º Simple supported beam notched impact strength (KJ / m2) 90º simply supported beam notched impact strength (KJ / m2) Example 1 220 221 Example 2 230 219 Example 3 240 230 Example 4 229 226 Example 5 230 230 Example 6 216 218 Example 7 223 223 Example 8 251 243

Claims

1. A continuous preparation method of a continuous glass fiber reinforced nylon 6 composite material, characterized in that: The steps include: After heating and melting caprolactam, a catalyst and an activator are added to obtain a nylon 6 prepolymer; Spray the KH-550 solution onto the surface of the glass fiber cloth and then dry it; The glass fiber cloth is pulled so that the glass fiber cloth is preheated to 100-130° C. during the pulling and moving process, and then the nylon 6 prepolymer is sprayed on both sides of the glass fiber cloth. The glass fiber cloth is then pulled through an inert gas protection environment at 130-200° C. to cause the nylon 6 prepolymer to undergo anionic polymerization on the surface of the glass fiber cloth, thereby realizing in-situ composite preparation of continuous glass fiber cloth reinforced nylon 6 composite materials.

2. The continuous preparation method of the continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The amount of the catalyst added is 0.0597 to 5.97 wt % of the amount of caprolactam used; The catalyst includes sodium methoxide, sodium hydroxide, potassium hydroxide, sodium caprolactam, metallic sodium or metallic potassium.

3. The continuous preparation method of the continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The method also includes the step of further spraying a DMF solution of 4-carboxybenzylacetonitrile and DCC on the surface of the glass fiber cloth sprayed with KH-550.

4. The continuous preparation method of continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The activator includes at least one of toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene diisocyanate or diphenylmethane diisocyanate.

5. The method for continuously preparing a continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The molar ratio of the activator to the catalyst is 0.95-1.05:

1.

6. The continuous preparation method of the glass fiber cloth reinforced nylon 6 composite material according to claim 1, characterized in that: The spraying amount of the nylon 6 prepolymer is 20 to 50 parts by weight of nylon 6 prepolymer for every 50 to 80 parts by weight of the glass fiber cloth on both sides.

7. The method for continuously preparing a continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The concentration of the KH550 solution is 0.1-1.5 wt %.

8. The method for continuously preparing a continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The glass fiber cloth includes plain glass fiber cloth, twill glass fiber cloth, satin glass fiber cloth, rib glass fiber cloth or basket glass fiber cloth.

9. The method for continuously preparing a continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The melting temperature is 70-120°C.

10. The method for continuously preparing a continuous glass fiber reinforced nylon 6 composite material according to claim 1, characterized in that: The glass fiber cloth passes through a protective atmosphere of 130-200° C. for 2 to 30 minutes; The protective atmosphere includes nitrogen, helium or argon.

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