Glass fiber impregnating compound for reinforcing APA6 resin as well as preparation method and application of glass fiber impregnating compound

Abstract

The invention discloses an impregnating compound for glass fibers for reinforcing APA6 resin and a preparation method and application of the impregnating compound for the glass fibers for reinforcing the APA6 resin, and the impregnating compound comprises the following components in parts by mass: 0.2-2 parts of a coupling agent; 2-24 parts of a film forming agent; 0.01 to 0.5 part of a lubricant A; 0.01 to 0.5 part of a lubricant B; the coupling agent is selected from at least one of gamma-methacryloxy propyl trimethoxy silane, gamma-aminopropyl trimethoxy silane and gamma-aminopropyl triethoxy silane; the silane coupling agent is selected from at least one of gamma-methacryloxy propyl trimethoxy silane, gamma-aminopropyl trimethoxy silane and gamma-aminopropyl triethoxy silane; the film forming agent is anionic / nonionic polyester polyurethane emulsion based on aliphatic isocyanate; the lubricant A is a nonionic emulsion type modified silane lubricant; and the lubricant B is a cationic amide salt lubricant. In a fiber-reinforced in-situ polymerization APA6 forming process, the impregnating compound provided by the invention improves the interface bonding performance of APA6 resin and glass fibers while improving the conversion rate of anionic polymerization reaction, thereby improving the comprehensive mechanical properties and fiber impregnation uniformity of a glass fiber-reinforced APA6 resin composite material.

Description

Technical Field

[0001] The invention belongs to the technical field of glass fiber surface treatment, and specifically relates to a sizing agent for glass fiber reinforced with APA6 resin, and a preparation method and application thereof. Background Art

[0002] Anionic polyamide 6 (APA6 for short) is obtained by anionic ring-opening polymerization of caprolactam. It has the advantages of high strength, wear resistance, self-lubrication, chemical resistance and strong chemical solvent resistance, and is widely used in the fields of automobiles, machinery, electronics, defense, aviation, etc. In the fiber-reinforced in-situ polymerization APA6 molding process, the interface bonding effect between the matrix resin and the fiber is particularly important for the mechanical properties of the product. If the sizing agent on the surface of the reinforcing fiber does not meet the requirements of the anionic polymerization reaction, it will not only affect the bonding quality between the resin and the fiber, but will even reduce the monomer conversion rate and hinder the reaction. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a wetting agent for glass fiber reinforced with APA6 resin and a preparation method and application thereof, so as to meet the needs of improving the conversion rate of anionic polymerization reaction in the fiber-reinforced in-situ polymerization APA6 molding process while enhancing the interface bonding performance between APA6 resin and glass fiber.

[0004] The present invention provides a sizing agent for glass fiber reinforced with APA6 resin, wherein the sizing agent comprises the following components in parts by mass:

[0005] Coupling agent: 0.2-2 parts;

[0006] Film-forming agent: 2-24 parts;

[0007] Lubricant A: 0.01-0.5 parts;

[0008] Lubricant B: 0.01-0.5 parts;

[0009] The coupling agent is at least one of γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane;

[0010] The film former is an anionic / nonionic polyester polyurethane emulsion based on aliphatic isocyanate;

[0011] The lubricant A is a non-ionic emulsion modified silane lubricant;

[0012] The lubricant B is a cationic amide salt lubricant.

[0013] The sizing agent for glass fibers that enhances APA6 resin, through the cooperation among various components and the optimization of their dosages, enables the interaction of specific types of coupling agents, film-forming agents, and lubricants, endowing the surface of glass fibers with good compatibility with the APA6 matrix resin, significantly improving the interfacial bonding ability between glass fibers and the APA6 substrate resin. Meanwhile, in the fiber-reinforced in-situ polymerization APA6 molding process, it increases the monomer conversion rate, promotes the occurrence of the polymerization reaction, and further improves the mechanical properties of the glass fiber-reinforced APA6 resin composite. Specifically, at least one of γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane is selected as the coupling agent, which can effectively link glass fibers and the APA6 matrix resin, significantly enhancing the bonding between glass fibers and the APA6 resin, while meeting the requirements of the anionic polymerization reaction for synthesizing APA6 resin. The selected film-forming agent is an anionic / nonionic polyester polyurethane emulsion based on aliphatic isocyanates. When applied to the preparation of glass fiber-reinforced APA6 resin composites, it can form a tough and elastic protective film on the surface of glass fibers, effectively preventing the fibers from being mechanically damaged during subsequent processing and use. At the same time, it can endow glass fibers with better flexibility and elasticity, enabling them to withstand a greater degree of deformation without breaking, thereby improving the overall performance of the composite. The selected lubricant A is a nonionic emulsion-type modified silane lubricant, and lubricant B is a cationic amide salt lubricant, which enhances the compatibility of the sizing agent with fibers and the APA6 resin, forming a stable bonding interface between glass fibers and the APA6 resin, thus achieving an efficient synergistic reinforcement effect between glass fibers and the APA6 resin in the composite. In the nonionic emulsion-type modified silane lubricant of lubricant A, the active groups of the silane hydrolyze to form silanols (Si-OH), which form Si-O-Si covalent bonds with the hydroxyl groups (-OH) on the surface of glass fibers through a condensation reaction, thereby constructing a stable organosilicon film layer on the surface of glass fibers and significantly enhancing the adhesion of the lubricant to glass fibers; in the cationic amide salt lubricant of lubricant B, the cationic groups in the molecules combine with the silanol groups (-Si-OH) on the surface of glass fibers through electrostatic attraction to form a lubricating layer, reducing friction, thereby improving the wettability of glass fibers. In the fiber-reinforced in-situ polymerization APA6 molding process, the cationic amide salt lubricant of lubricant B promotes the chemical bonding between the silane coupling agent and the APA6 resin, improving the interfacial shear strength of the composite. Compared with the existing technology, in the fiber-reinforced in-situ polymerization APA6 molding process, the sizing agent of the present invention increases the conversion rate of the anionic polymerization reaction while enhancing the bonding force between the APA6 resin and glass fibers, improving the mechanical properties, yellowing resistance, and high-temperature resistance of the glass fiber-reinforced APA6 resin composite.

[0014] The non-ionic emulsion-type modified silane lubricant refers to a lubricant that belongs to both non-ionic emulsion-type lubricants and modified silane lubricants.

[0015] The cationic amide salt lubricant refers to a lubricant that belongs to both cationic lubricants and amide salt lubricants.

[0016] Preferably, the coupling agent is γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0017] In the fiber-reinforced in-situ polymerization APA6 molding process, the coupling agents γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane in this solution can further increase the conversion rate of anionic polymerization and enhance the bonding strength between the APA6 resin and the fibers.

[0018] More preferably, the mass ratio of γ-methacryloxypropyltrimethoxysilane to γ-aminopropyltriethoxysilane is (0.5 - 2):1. For example, it can be 0.5:1, 1:1, 1.5:1, 2:1, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0019] In this solution, the mass ratio of γ-methacryloxypropyltrimethoxysilane to γ-aminopropyltriethoxysilane is (0.5 - 2):1, which can further increase the conversion rate of anionic polymerization and enhance the bonding strength between the APA6 resin and the fibers.

[0020] Preferably, by mass, the coupling agent is 0.6 - 1.2 parts.

[0021] Preferably, by mass, the film-forming agent is 8 - 20 parts.

[0022] Preferably, by mass, lubricant A is 0.1 - 0.5 parts and lubricant B is 0.1 - 0.5 parts.

[0023] Preferably, the mass ratio of lubricant A to lubricant B is (1 - 4):1. For example, it can be 1:1, 2:1, 3:1, 4:1, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0024] In the fiber-reinforced in-situ polymerization APA6 molding process, the mass ratio of lubricant A to lubricant B in the present invention being (1 - 4):1 can further improve the compatibility between the APA6 resin and glass fibers, form a stable bonding interface between the glass fibers and the APA6 resin, thereby achieving an efficient synergistic reinforcement effect between the glass fibers and the APA6 resin in the composite material, and at the same time improving the fiber impregnation uniformity.

[0025] The present invention provides a method for preparing a sizing agent for glass fibers reinforcing APA6 resin, comprising the following steps:

[0026] S1: Add a pH regulator to water and adjust the pH to 3 - 4;

[0027] S2: Add a coupling agent and stir to mix;

[0028] S3: Add lubricant A and lubricant B diluted with water and stir to mix;

[0029] S4: Add a film-forming agent diluted with water, stir to mix, and dilute to obtain the sizing agent for glass fibers reinforcing APA6 resin.

[0030] In the method for preparing the sizing agent for glass fibers reinforcing APA6 resin according to the present invention, first, a pH regulator is used to adjust the pH to 3 - 4, and a coupling agent is added, which can accelerate the hydrolysis of siloxanyl (-Si-O-R) into silanol (-Si-OH), promote the condensation reaction with Si-OH on the surface of glass fibers, and form stable covalent bonds.

[0031] Preferably, in the step S2, the stirring and mixing is carried out until there are no oil flowers on the surface of the solution.

[0032] The present invention also provides an application of the sizing agent for glass fibers reinforcing APA6 resin in glass fiber reinforced APA6 resin. Specific Embodiments

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0034] The raw materials used in the following Example 1 are specifically as follows:

[0035] The film-forming agent is selected as Bayer XP 2569;

[0036] Lubricant A is selected as CSG Institute NBR - 1240;

[0037] Lubricant B is selected as CSG Institute NBR - 1270.

[0038] Example 1

[0039] Calculated by mass parts, the sizing agent for glass fibers reinforcing APA6 resin in this example comprises the following components:

[0040] Coupling agent: 0.4 part of γ-methacryloxypropyltrimethoxysilane and 0.4 part of γ-aminopropyltriethoxysilane;

[0041] Film-forming agent: 15 parts;

[0042] Lubricant A: 0.4 part of nonionic emulsion-modified silane lubricant;

[0043] Lubricant B: 0.1 part of cationic amide salt lubricant;

[0044] The preparation method of the sizing agent for glass fiber reinforcing APA6 resin in this example is as follows:

[0045] S1: Add 10 parts of deionized water to the reaction kettle, start the mechanical stirrer, and then add a pH regulator to adjust the pH to 3-4;

[0046] S2: Then add 0.4 part of γ-methacryloxypropyltrimethoxysilane and 0.4 part of γ-aminopropyltriethoxysilane in sequence, and stir for 40 min until there is no oil film on the surface;

[0047] S3: Weigh 0.4 part of nonionic emulsion-modified silane lubricant and dilute it with 4 parts of deionized water and add it to the reaction kettle. Weigh 0.1 part of cationic amide salt lubricant and dilute it with 6 parts of deionized water and add it to the reaction kettle;

[0048] S4: Dilute 15 parts of anionic / nonionic polyester polyurethane emulsion of aliphatic isocyanate with 30 parts of deionized water and add it to the reaction kettle, and finally add 33 parts of deionized water, and stir for 20 minutes to obtain the sizing agent for glass fiber reinforcing APA6 resin.

[0049] Example 2

[0050] In the sizing agent components for glass fiber reinforcing APA6 resin in this example, except that γ-aminopropyltriethoxysilane is replaced by γ-aminopropyltrimethoxysilane, the others are the same as in Example 1.

[0051] The preparation method of the sizing agent for glass fiber reinforcing APA6 resin in this example is the same as that in Example 1.

[0052] Example 3

[0053] In the sizing agent components for glass fiber reinforcing APA6 resin in this example, except that the coupling agent is 0.1 part of γ-methacryloxypropyltrimethoxysilane and 0.7 part of γ-aminopropyltriethoxysilane, the others are the same as in Example 1.

[0054] The preparation method of the sizing agent for glass fiber reinforcing APA6 resin in this example is the same as that in Example 1.

[0055] Example 4

[0056] In the sizing composition for glass fibers reinforcing APA6 resin according to this embodiment, except that lubricant A is 0.2 parts of a non-ionic emulsion type modified silane lubricant and lubricant B is 0.3 parts of a cationic amide salt lubricant, the rest is the same as in Example 1.

[0057] The preparation method of the sizing for glass fibers reinforcing APA6 resin in this embodiment is the same as in Example 1.

[0058] Comparative Example 1

[0059] In the sizing composition for glass fibers reinforcing APA6 resin in this embodiment, except that the coupling agent is 0.8 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, the rest is the same as in Example 1.

[0060] The preparation method of the sizing for glass fibers reinforcing APA6 resin in this embodiment is the same as in Example 1.

[0061] Comparative Example 2

[0062] In the sizing composition for glass fibers reinforcing APA6 resin in this embodiment, except that the film-forming agent is South Glass Institute NBR-210-50, the rest is the same as in Example 1.

[0063] The preparation method of the sizing for glass fibers reinforcing APA6 resin in this embodiment is the same as in Example 1.

[0064] Comparative Example 3

[0065] In the sizing composition for glass fibers reinforcing APA6 resin in this embodiment, except that lubricant A is 0.2 parts of non-ionic mineral oil octylphenol polyoxyethylene ether and 0.2 parts of dimethyl silicone oil emulsion with a viscosity of 350 CS, the rest is the same as in Example 1.

[0066] The preparation method of the sizing for glass fibers reinforcing APA6 resin in this embodiment is the same as in Example 1.

[0067] Preparation of Glass Fiber Reinforced APA6 Resin Composite

[0068] S1. Use alkali-free glass fibers (E-glass, monofilament diameter 13 μm), dry them in an oven at 120 °C for 2 hours to remove surface moisture, and obtain treated glass fibers.

[0069] S2. Pass the treated glass fibers through an impregnation tank (the sizing in the impregnation tank is the sizing prepared in the above examples and comparative examples respectively, at a temperature of 30 °C), control the sizing amount to be 1.2 wt% ± 0.1 wt%, and wind up after infrared drying (80 °C, 3 minutes) to obtain treated reinforced glass fiber bundles.

[0070] S3. The caprolactam monomer is heated to 110 °C. Under nitrogen protection, 1000 parts by mass of the monomer are completely melted by mechanical stirring, and then 1.5 parts by mass of sodium methoxide and 4.5 parts by mass of toluene diisocyanate are added in sequence. After complete melting and uniform mixing, the mixed reaction solution is quickly injected into a flat mold preheated to the polymerization temperature (150 - 170 °C) and laid with reinforcing glass fiber bundles by the resin transfer molding process (RTM process) for curing and forming. After reacting at the polymerization temperature for 1 h, it is cooled to room temperature and demolded to obtain the glass fiber-reinforced APA6 resin composite material.

[0071] Performance testing

[0072] The glass fiber-reinforced APA6 resin composite materials prepared with the sizing agents of the above examples and comparative examples are subjected to the following performance tests.

[0073] (1) The tensile properties of the composite material are tested according to the ASTM D3039 test method.

[0074] (2) The flexural modulus of the composite material is tested according to the ASTM D790 test method.

[0075] (3) The interlaminar shear strength of the composite material is tested according to the ASTM D2344 test method.

[0076] (4) Fiber impregnation uniformity:

[0077] Evaluation criteria:

[0078] Excellent: No visible white filaments or dry spots;

[0079] Good: Slight local white filaments;

[0080] Medium: Obvious dry spots or hair filaments;

[0081] Poor: Large area of unimpregnated region.

[0082] Evaluation method: After cutting the cross-section and polishing, observe under a microscope (100×) combined with visual inspection.

[0083] The results of the above performance tests are shown in Table 1 below:

[0084] Table 1

[0085]

[0086] As can be seen from Table 1:

[0087] The sizing agents for glass fibers for reinforcing APA6 resin prepared in Examples 1 to 4 all fall within the scope of the sizing agents protected by the technical solution of the present invention. The glass fiber-reinforced APA6 resin composites prepared using the sizing agents of Examples 1 to 4 showed good test results in the performance tests of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity. That is, the glass fiber-reinforced APA6 resin composites prepared using the sizing agents for glass fibers for reinforcing APA6 resin provided by the present invention have good comprehensive mechanical properties and fiber impregnation uniformity. However, the sizing agents for glass fibers for reinforcing APA6 resin prepared in Comparative Examples 1 to 3 do not fall within the scope of the sizing agents protected by the technical solution of the present invention. The glass fiber-reinforced APA6 resin composites prepared using the sizing agents of Comparative Examples 1 to 3 showed significantly deteriorated performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity. That is, the glass fiber-reinforced APA6 resin composites prepared using the sizing agents of Comparative Examples 1 to 3 cannot have both good comprehensive mechanical properties and fiber impregnation uniformity.

[0088] Compared with the coupling agents used in the sizing agent for glass fibers for reinforcing APA6 resin in Example 1, which are γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane, the coupling agents used in the sizing agent of Example 2 are γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltrimethoxysilane. That is, γ-aminopropyltrimethoxysilane is used to replace γ-aminopropyltriethoxysilane in Example 1. The coupling agents used in the sizing agent of Example 2 are not the further preferred composite coupling agents, namely γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane. The glass fiber-reinforced APA6 resin composites prepared using the sizing agent of Example 2 showed worse performance test results in terms of longitudinal tensile strength, flexural modulus, and interlaminar shear strength than those of Example 1. This shows that when preparing the sizing agent for glass fibers for reinforcing APA6 resin of the present invention, using the composite coupling agents of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane can further improve the conversion rate of anionic polymerization reaction in the fiber-reinforced in-situ polymerization APA6 molding process and further enhance the bonding force between the APA6 resin and the fiber.

[0089] Compared with Example 1 where the mass ratio of the composite coupling agents γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane used in the sizing agent for glass fibers reinforcing APA6 resin is 1:1, the mass ratio of the composite coupling agents γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane used in Example 3 is 1:7, that is, it is not within the further preferred range of the mass ratio of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane being (0.5 - 2):1. For the glass fiber reinforced APA6 resin composite prepared with the sizing agent of Example 3, the performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity are worse than those of Example 1. This shows that when preparing the sizing agent for glass fibers reinforcing the APA6 resin of the present invention, adopting a mass ratio of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane of (0.5 - 2):1 can further improve the conversion rate of anionic polymerization reaction in the fiber-reinforced in-situ polymerization APA6 molding process, and at the same time further enhance the bonding force between the APA6 resin and the fibers.

[0090] Compared with Example 1 where the mass ratio of lubricant A (nonionic emulsion-modified silane lubricant) to lubricant B (cationic amide salt lubricant) used in the sizing agent for glass fibers reinforcing APA6 resin is 4:1, the mass ratio of lubricant A to lubricant B used in Example 4 is 2:3, that is, it is not within the further preferred range of the mass ratio of lubricant A to lubricant B being (1 - 4):1. For the glass fiber reinforced APA6 resin composite prepared with the sizing agent of Example 4, the performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity are worse than those of Example 1. This shows that when preparing the sizing agent for glass fibers reinforcing the APA6 resin of the present invention, adopting a mass ratio of lubricant A to lubricant B of (1 - 4):1 can further improve the compatibility between the APA6 resin and glass fibers in the fiber-reinforced in-situ polymerization APA6 molding process, form a stable bonding interface between the glass fibers and the APA6 resin, thereby realizing the efficient synergistic reinforcement effect of the glass fibers and the APA6 resin in the composite material, and at the same time improving the fiber impregnation uniformity.

[0091] Compared with the coupling agents used in the sizing agent for glass fibers reinforcing APA6 resin in Example 1, which are γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane, the coupling agent used in the sizing agent of Comparative Example 1 is 3-(2,3-epoxypropoxy)propyltrimethoxysilane. That is, the coupling agent 3-(2,3-epoxypropoxy)propyltrimethoxysilane used in the sizing agent of Comparative Example 1 is not the specific coupling agent in the technical solution of the present invention. Compared with Example 1, for the glass fiber reinforced APA6 resin composite prepared using the sizing agent of Comparative Example 1, the performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity are significantly deteriorated. Thus, it is shown that only the sizing agent prepared using the specific coupling agent of the present invention can improve the conversion rate of anionic polymerization reaction and enhance the bonding force between the APA6 resin and the fiber in the fiber-reinforced in-situ polymerization APA6 molding process, and further enable the prepared glass fiber reinforced APA6 resin composite to have good comprehensive mechanical properties and fiber impregnation uniformity.

[0092] Compared with the film-forming agent used in the sizing agent for glass fibers reinforcing APA6 resin in Example 1, which is Bayer XP2569 (anionic / nonionic polyester polyurethane emulsion based on aliphatic isocyanate), the film-forming agent used in the sizing agent of Comparative Example 2 is CSG NBR-210-50 (epoxy resin emulsion with medium molecular weight) from CSG. That is, the film-forming agent CSG NBR-210-50 used in the sizing agent of Comparative Example 2 is not the specific film-forming agent in the technical solution of the present invention. Compared with Example 1, for the glass fiber reinforced APA6 resin composite prepared using the sizing agent of Comparative Example 2, the performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity are significantly deteriorated. Thus, it is shown that only the sizing agent prepared using the specific film-forming agent of the present invention can form a tough and elastic protective film on the surface of the glass fiber and at the same time improve the conversion rate of anionic polymerization reaction in the fiber-reinforced in-situ polymerization APA6 molding process, and further enable the prepared glass fiber reinforced APA6 resin composite to have good comprehensive mechanical properties and fiber impregnation uniformity.

[0093] Compared with Example 1 where the lubricant A used for the sizing agent of glass fiber for enhancing APA6 resin is 0.4 parts of a non-ionic emulsion-type modified silane lubricant (NBR-1240 of CSG Institute) and the lubricant B is 0.1 part of a cationic amide salt lubricant (NBR-1270 of CSG Institute), the lubricant system used in Comparative Example 3 is 0.2 parts of non-ionic mineral oil octylphenol polyoxyethylene ether, 0.2 parts of dimethyl silicone oil emulsion with a viscosity of 350 CS, and 0.1 part of a cationic amide salt lubricant (NBR-1240 of CSG Institute), that is, 0.2 parts of non-ionic mineral oil octylphenol polyoxyethylene ether and 0.2 parts of dimethyl silicone oil emulsion with a viscosity of 350 CS are used to replace 0.4 parts of the non-ionic emulsion-type modified silane lubricant (NBR-1240 of CSG Institute) as lubricant A in Example 1. The lubricant system used in the sizing agent of Comparative Example 3 is not the specific lubricant in the technical solution of the present invention. Compared with Example 1, for the glass fiber reinforced APA6 resin composite prepared using the sizing agent of Comparative Example 3, the performance test results in terms of longitudinal tensile strength, flexural modulus, interlaminar shear strength, and fiber impregnation uniformity are significantly deteriorated. Thus, it is shown that only by using the sizing agent prepared with the specific lubricant of the present invention can the compatibility between APA6 resin and glass fiber be improved in the in-situ polymerization molding process of fiber-reinforced APA6, enabling a stable bonding interface to be formed between the glass fiber and APA6 resin, thereby achieving an efficient synergistic strengthening effect between the glass fiber and APA6 resin in the composite, and at the same time improving the fiber impregnation uniformity.

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced, but these modifications or replacements are all within the protection scope of the present invention.

Claims

1. A sizing agent for glass fibers that enhances APA6 resin, characterized in that, By mass parts, the sizing agent comprises the following components: Coupling agent: 0.2 - 2 parts; Film-forming agent: 2 - 24 parts; Lubricant A: 0.01 - 0.5 part; Lubricant B: 0.01 - 0.5 part; The coupling agent is at least one of γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane; The film-forming agent is an anionic / nonionic polyester polyurethane emulsion based on aliphatic isocyanate; The lubricant A is a nonionic emulsion-type modified silane lubricant; The lubricant B is a cationic amide salt lubricant.

2. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1, wherein The coupling agent is γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

3. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1 or 2, characterized in that The mass ratio of the γ-methacryloxypropyltrimethoxysilane to the γ-aminopropyltriethoxysilane is (0.5 - 2):

1.

4. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1, characterized in that, By mass parts, the coupling agent: 0.6 - 1.2 parts.

5. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1, characterized in that, By mass parts, the film-forming agent: 8 - 20 parts.

6. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1, characterized in that, By mass parts, lubricant A: 0.1 - 0.5 part, lubricant B: 0.1 - 0.5 part.

7. The sizing agent for glass fibers for enhancing APA6 resin according to claim 1, characterized in that, The mass ratio of the lubricant A to the lubricant B is (1 - 4):

1.

8. A preparation method of a sizing agent for glass fibers for enhancing APA6 resin according to any one of claims 1 to 7, characterized in that, It includes the following steps: S1: Add a pH regulator to water and adjust the pH to 3 - 4; S2: Add the coupling agent and stir to mix; S3: Add the diluted lubricant A and lubricant B with water and stir to mix; S4: Add the diluted film-forming agent with water, stir to mix, and dilute to obtain the sizing agent for glass fibers reinforcing APA6 resin.

9. The preparation method of the sizing agent for glass fiber for enhancing APA6 resin according to claim 8, characterized in that, In the S2, the stirring and mixing is to stir until there are no oil flowers on the surface of the solution.

10. Application of a sizing agent for glass fibers reinforcing APA6 resin according to any one of claims 1 - 7 in glass fiber reinforced APA6 resin.

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