Low-float high-flowability high-glass-fiber-reinforced MXD6 material, preparation method and application thereof

Abstract

This invention discloses a high-glass fiber reinforced MXD6 material with low fiber float and high flowability, its preparation method, and its applications. It relates to the field of polymer materials technology. The high-glass fiber reinforced MXD6 material comprises the following components by weight: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 parts antioxidant, 0.1-1 parts nucleating agent, 0.1-1 parts heat resistant agent, 0.1-1 parts lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-float agent. The hyperbranched anti-float agent is composed of three hyperbranched compounds compounded and kneaded. This modification method improves the compatibility of MXD6 with high-content glass fiber, as well as the mechanical properties and gloss of the material. Furthermore, the prepared high-glass fiber reinforced MXD6 material is easy to injection mold and can be widely applied to applications such as replacing steel with plastics.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, and specifically relates to a high glass fiber reinforced MXD6 material with low fiber float and high flowability, its preparation method and application. Background Technology

[0002] MXD6 (poly(m-phenylene adipamide)) is a semi-aromatic polyamide with excellent barrier properties, chemical resistance, and dimensional stability. With the trend towards lightweighting, the demand for high-glass fiber reinforced MXD6 materials (glass fiber content ≥50%) is increasing in applications such as drone propellers, automotive engine peripheral components, and plastic-to-steel replacement scenarios.

[0003] Currently, commonly used glass fiber surface impregnators on the market are mainly designed for PA6 / PA66, and have low reactivity with the terminal amino groups of MXD6, resulting in weak bonding between glass fiber and the resin matrix. When the glass fiber content exceeds 60%, the material is prone to a sharp drop in mechanical properties, extrusion difficulties, and even the inability to form strands. Meanwhile, anti-floating fiber agents are introduced to improve surface fiber floating; however, traditional anti-floating fiber agents often sacrifice material stiffness and strength, and are mostly in powder form. In actual mass production, they are prone to settling at the bottom and clogging the feed port, leading to significant fluctuations in product performance. Furthermore, with high glass fiber filler, the melt viscosity of the material increases sharply, making filling difficult when injection molding large, thin-walled parts.

[0004] Therefore, how to develop a material that can significantly improve the interfacial bonding between MXD6 and glass fiber, while also maintaining high fluidity, low fiber float, and suitability for industrial mass production, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a high glass fiber reinforced MXD6 material with low fiber float and high fluidity, its preparation method and application, so as to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the first aspect of the present invention provides a high glass fiber reinforced MXD6 material with low fiber float and high fluidity, comprising the following components by weight: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 parts antioxidant, 0.1-1 parts nucleating agent, 0.1-1 parts heat resistant agent, 0.1-1 parts lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-float fiber agent.

[0007] In the first aspect, the hyperbranched anti-floating fiber agent is compounded and kneaded from a first hyperbranched compound, a second hyperbranched compound, and a third hyperbranched compound in a mass ratio of (10-20):(20-30):(50-70), wherein the first hyperbranched compound is a polyamide with an amino end group, the second hyperbranched compound is a polyamide grafted with polyacrylic acid, and the third hyperbranched compound is a polyamide modified with MXD6.

[0008] In the first aspect, the method for preparing the first hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 to a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, and removing the solvent to obtain a polyamide hyperbranched compound with amine end groups; the method for preparing the second hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 to a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, adding acrylic acid and an initiator, reacting at 70-90°C for 3 hours, and removing the solvent to obtain a polyacrylic acid-grafted polyamide hyperbranched compound. The compound; wherein the molar ratio of isophthalic acid to acrylic acid is 1:3-1:20, and the amount of initiator added is 0.2-2% of the mass of acrylic acid; the preparation method of the third hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine to a reaction vessel at a molar ratio of 1:1.4-1:3, reacting under nitrogen protection at 100-170°C until anhydrous formation, adding MXD6 resin with carboxyl end groups, reacting at 150-200°C until anhydrous formation, removing the solvent, and obtaining the MXD6-modified polyamide hyperbranched compound; wherein the molar ratio of isophthalic acid to MXD6 resin is 1:1-1:3.

[0009] In the first aspect, the first hyperbranched compound, the second hyperbranched compound, and the third hyperbranched compound are in a mass percentage ratio of 15%:25%:60%.

[0010] In the first aspect, the hyperbranched anti-buoyancy fiber agent has a number-average molecular weight of 10,000-60,000 g / mol and a melting point of 50-200 °C.

[0011] In the first aspect, the MXD6 nylon has a relative viscosity of 2.0-2.2 and a melting point of 235-240°C.

[0012] In the first aspect, the chopped length of the flat glass fiber is 2-10 mm, the fiber diameter is 4-15 μm, and the flatness is 3:1-4:1.

[0013] The second aspect of this invention provides a method for preparing a high glass fiber reinforced MXD6 material with low fiber float and high flowability. The preparation method includes the following steps: S1, weighing each raw material component according to the weight proportions of the high glass fiber reinforced MXD6 material with low fiber float and high flowability described in the first aspect; S2, premixing dried MXD6 nylon with antioxidant, nucleating agent, heat resistant agent, lubricant, color masterbatch, and hyperbranched anti-float agent together in a high-speed mixing tank to obtain a premix; S3, conveying the premix to a twin-screw extruder through the main feed inlet, and conveying flat glass fibers to a twin-screw extruder through the side feed inlet. All material components are sheared, melt-blended, extruded, and granulated by the screw to obtain the high glass fiber reinforced MXD6 material.

[0014] The third aspect of this invention provides an application of the high glass fiber reinforced MXD6 material with low fiber float and high flowability described in the first aspect in the manufacture of plastic parts for drones, automobiles, and electronic appliances.

[0015] A fourth aspect of the present invention provides a plastic part made of the high glass fiber reinforced MXD6 material with low float and high flowability described in the first aspect, and at least one auxiliary material.

[0016] Beneficial effects: This invention provides a high-glass fiber reinforced MXD6 material with low fiber float and high flowability, comprising the following components by weight: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 parts antioxidant, 0.1-1 parts nucleating agent, 0.1-1 parts heat resistant agent, 0.1-1 parts lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-float fiber agent. By reinforcing and modifying MXD6 with flat glass fiber and adding processing aids such as antioxidants, nucleating agents, heat resistant agents, lubricants, and color masterbatch, the processing performance of the material is improved. Simultaneously, a self-made hyperbranched anti-float fiber agent is used to avoid fiber float. Furthermore, the synergistic effect of flat glass fiber and hyperbranched anti-float fiber agent ensures that the material maintains superior mechanical properties and flowability even under high glass fiber filling conditions, thereby guaranteeing perfect filling capability in the manufacture of plastic parts for drones, automobiles, and electronic appliances.

[0017] The preparation method of this invention significantly improves the compatibility of MXD6 resin with high glass fiber content by modifying the end groups of hyperbranched anti-buoyancy fiber agent, further enhancing the mechanical strength and gloss of high glass fiber MXD6 composite materials. This successfully prepares high glass fiber reinforced MXD6 materials with excellent performance and ultra-high glass fiber content (70%), possessing significant economic and application value. The mechanical properties of conventional high glass fiber content (50%, 60%) high glass fiber reinforced MXD6 materials are superior to those of high glass fiber reinforced MXD6 materials with added commercially available anti-buoyancy fiber agents.

[0018] The high glass fiber reinforced MXD6 material of the present invention, which has low fiber float and high flowability, is prepared by introducing a self-made MXD6 special anti-fiber float agent. In addition to having the characteristics of a 70% glass fiber content MXD6 composite material that can be stably mass-produced with excellent performance, it also has high modulus, excellent mechanical strength, good anti-fiber float performance, high gloss, good flowability, and is not easy to stick to the feed port.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 These are test appearance diagrams of Examples 1-3 and Comparative Examples 1-2 in this invention. Detailed Implementation

[0022] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0023] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0024] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be obtained by purchasing them from the market or by existing methods.

[0025] This invention provides a high glass fiber reinforced MXD6 material with low fiber float and high flowability, comprising the following components by weight: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 parts antioxidant, 0.1-1 parts nucleating agent, 0.1-1 parts heat resistant agent, 0.1-1 parts lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-float fiber agent.

[0026] Specifically, the present invention provides a high-glass fiber reinforced MXD6 material with low fiber float and high flowability, comprising the following components by weight: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 parts antioxidant, 0.1-1 parts nucleating agent, 0.1-1 parts heat resistant agent, 0.1-1 parts lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-float fiber agent. By using flat glass fiber to reinforce and modify MXD6, and adding processing aids such as antioxidants, nucleating agents, heat resistant agents, lubricants, and color masterbatch, the processing performance of the material is improved. Simultaneously, a self-made hyperbranched anti-float fiber agent is used to avoid fiber float. Furthermore, the synergistic effect of flat glass fiber and hyperbranched anti-float fiber agent ensures that the material retains superior mechanical properties and flowability even under high glass fiber filling conditions, thereby ensuring perfect filling capability in the manufacture of plastic parts for drones, automobiles, and electronic appliances.

[0027] In some possible embodiments, the hyperbranched anti-floating fiber agent is compounded and kneaded from a first hyperbranched compound, a second hyperbranched compound, and a third hyperbranched compound in a mass ratio of (10-20):(20-30):(50-70), wherein the first hyperbranched compound is a polyamide with amine end groups, the second hyperbranched compound is a polyamide grafted with polyacrylic acid, and the third hyperbranched compound is a polyamide modified with MXD6.

[0028] Specifically, introducing a self-made hyperbranched anti-floating fiber agent into a system with high glass fiber and MXD6 as the main resin can effectively improve the interfacial force between MXD6 nylon and glass fiber. At the same time, its special hydrodynamic effect can effectively reduce the resistance of the melt in shear flow. In specific embodiments, the first hyperbranched compound is a polyamide with amine end groups, the second hyperbranched compound is a polyamide grafted with polyacrylic acid, and the third hyperbranched compound is a polyamide modified with MXD6. The hyperbranched compound modified with oligoacrylic acid readily undergoes a grafting reaction with the amine end groups of the main resin MXD6 nylon during high-temperature melt blending. Simultaneously, after MXD6 is grafted with the hyperbranched compound modified with oligoacrylic acid, the molecular chain ends are rich in active carboxyl groups, which readily react with the hydroxyl groups on the surface of the flat glass fiber, effectively improving the interfacial force between MXD6 nylon and glass fiber. The hyperbranched compound with active amine end groups and MXD6 modification has a structure similar to and compatible with the structure of the main resin MXD6 nylon, which can effectively improve the mixing uniformity and further react with the hyperbranched compound grafted with oligoacrylic acid, reducing the precipitation of small molecules. The hyperbranched anti-floating fiber agent composed of the above three hyperbranched compounds can not only eliminate the floating fibers of the material, but also effectively weaken the inter-chain forces of MXD6, increase the slippage ability of the molecular chain, and effectively improve the flowability of MXD6 material.

[0029] It should be further noted that the commonly used glass fibers for nylon and their surface wetting agents and anti-floating fiber agents in the market are mainly designed for conventional aliphatic polyamides. Compared with conventional aliphatic polyamides, the effective functional groups of commonly used glass fibers for nylon and their surface wetting agents and anti-floating fiber agents have lower reactivity and compatibility with MXD6. This is the fundamental reason why the mechanical strength of glass fiber reinforced MXD6 composites is lower than that of glass fiber reinforced PA66 and other nylon materials. Moreover, when the glass fiber content is higher than 50%, its mechanical strength will further decrease. However, the use of the self-made hyperbranched anti-floating fiber agent combined with flat glass fibers can significantly reduce the surface floating fiber level, improve the smoothness and gloss of the material appearance, and improve the melt flowability of the material.

[0030] In some possible embodiments, the preparation method of the first hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 to a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, and removing the solvent to obtain a polyamide hyperbranched compound with amine end groups; the preparation method of the second hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 to a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, adding acrylic acid and an initiator, reacting at 70-90°C for 3 hours, and removing the solvent to obtain a polyacrylic acid-grafted polyamide hyperbranched compound. A branched compound; wherein the molar ratio of isophthalic acid to acrylic acid is 1:3-1:20, and the amount of initiator added is 0.2-2% of the mass of acrylic acid; the preparation method of the third hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine to a reaction vessel at a molar ratio of 1:1.4-1:3, reacting under nitrogen protection at 100-170℃ until anhydrous formation, adding MXD6 resin with carboxyl end groups, reacting at 150-200℃ until anhydrous formation, removing the solvent, and obtaining the MXD6-modified polyamide hyperbranched compound; wherein the molar ratio of isophthalic acid to MXD6 resin is 1:1-1:3.

[0031] Specifically, the preparation method of the first hyperbranched compound includes the following steps: a certain amount of isophthalic acid, p-phenylenediamine, reaction catalyst, and dehydrating agent are added to a reaction vessel equipped with a stirrer, condenser, water separator, and thermometer. The mixture is purged three times with nitrogen under stirring, then heated to 100-120℃ for 30 minutes under a nitrogen atmosphere, and then heated to 120-170℃ until no water is generated in the water separator. The total monomer ratio of isophthalic acid to p-phenylenediamine can be 1:1.4-1:3. The generated hyperbranched compound has amine end groups. After no water is generated in the water separator, the dehydrating agent is removed while hot under vacuum (to lower the boiling point). The product is then removed and cooled to obtain a polyamide hyperbranched compound with amine end groups, the general molecular formula of which is shown below: The preparation method of the second hyperbranched compound specifically includes the following steps: A certain amount of isophthalic acid, p-phenylenediamine, reaction catalyst, and dehydrating agent are added to a reaction vessel equipped with a stirrer, condenser, water separator, and thermometer. The mixture is purged three times with nitrogen under stirring, then heated to 100-120℃ for 30 minutes under a nitrogen atmosphere, and subsequently heated to 120-170℃. No water is generated in the water separator. The total monomer ratio of isophthalic acid to p-phenylenediamine can be 1:1.4-1:3. The resulting hyperbranched compound… The end group of the compound is an amine group. Then, a certain amount of acrylic acid monomer and initiator are added. The total monomer ratio of isophthalic acid, p-phenylenediamine, and acrylic acid is 1:3:3-1:1.4:20. The initiator is benzoyl peroxide, and its content is 0.2%-2% of the mass of the acrylic acid monomer. After reacting at 70-90℃ for 3 hours, the dehydrating agent is removed under vacuum (to lower the boiling point) while hot. The product is then removed, cooled, and pulverized to obtain a hyperbranched polyamide compound grafted with polyacrylic acid. Its general molecular structure formula is shown below: The preparation method of the third hyperbranched compound specifically includes the following steps: A certain amount of isophthalic acid, p-phenylenediamine, a reaction catalyst, and a dehydrating agent are added to a reaction vessel equipped with a stirrer, condenser, water separator, and thermometer. The mixture is purged three times with nitrogen under stirring, then heated to 100-120℃ under a nitrogen atmosphere for 30 minutes, followed by heating to 120-170℃. No water is generated in the water separator. The total monomer ratio of isophthalic acid to p-phenylenediamine can be 1:1.4-1: 3. The generated hyperbranched compound has amine end groups. Then, MXD6 with a degree of polymerization of 10-50 and carboxyl end groups is added. The total monomer ratio of isophthalic acid, p-phenylenediamine, and MXD6 is 1:3:3-1:1.4:1. The reaction is carried out at 150-200℃ until no water is generated in the water separator. While hot, the dehydrating agent is removed under vacuum (to lower the boiling point). The product is then removed, cooled, and pulverized to obtain the MXD6-modified polyamide hyperbranched compound, whose general molecular structure is shown below: In some possible embodiments, the first hyperbranched compound, the second hyperbranched compound, and the third hyperbranched compound are in a mass percentage ratio of 15%:25%:60%.

[0032] In some possible embodiments, the hyperbranched anti-buoyancy fiber agent has a number-average molecular weight of 10,000-60,000 g / mol and a melting point of 50-200°C.

[0033] In this application, the first hyperbranched compound, the second hyperbranched compound, and the third hyperbranched compound prepared above are kneaded in a certain proportion to prepare a granular hyperbranched anti-floating fiber agent, with a number-average molecular weight between 10,000 and 60,000 g / mol and a melting point between 50 and 200 °C, thereby improving the anti-floating fiber properties and flowability of the composite material.

[0034] In some possible embodiments, the MXD6 nylon has a relative viscosity of 2.0-2.2 and a melting point of 235-240°C.

[0035] The viscosity of MXD6 nylon, measured according to ISO 307 standard, is 2.0-2.2 at a test temperature of 25℃, with a terminal amine group content of 30-80 mmol / kg. The resin is dissolved in 96% concentrated sulfuric acid to obtain a resin concentration of 0.01 g / ml, which is then measured using an Ubbelohde viscometer. Preferably, the viscosity of MXD6 resin is 2.1, and its melting point is 236℃-239℃.

[0036] In some possible embodiments, the chopped length of the flat glass fiber is 2-10 mm, the fiber diameter is 4-15 μm, and the flatness is 3:1-4:1.

[0037] In this application, flat glass fibers are used instead of conventional round glass fibers, which not only reduces the orientation stress during the flow of glass fibers and further improves the surface fiber floating, but also maintains a high modulus under high glass fiber filling.

[0038] Based on a general inventive concept, the second aspect of this invention provides a method for preparing a high-glass fiber reinforced MXD6 material with low fiber float and high flowability, the preparation method comprising the following steps: S1. Weigh each raw material component according to the weight proportions of the low-float fiber, high-flowability, high-glass fiber reinforced MXD6 material described in the first aspect. S2. The dried MXD6 nylon, antioxidant, nucleating agent, heat resistant agent, lubricant, color masterbatch, and hyperbranched anti-floating fiber agent are premixed together in a high-speed mixing tank to obtain a premix. S3. The premix is ​​fed into the twin-screw extruder through the main feed inlet, and the flat glass fiber is fed into the twin-screw extruder through the side feed inlet. All material components are sheared, melt-blended, extruded and granulated by the screw to obtain the high glass fiber reinforced MXD6 material.

[0039] Specifically, this application provides a method for preparing a high-glass fiber reinforced MXD6 material with low fiber float and high flowability. First, the components are weighed according to the above-mentioned raw material ratio, and MXD6 nylon is dried at 80-100℃. Then, the weighed MXD6 nylon, antioxidant, nucleating agent, heat resistant agent, lubricant, color masterbatch, and hyperbranched anti-float agent are mixed to obtain a uniformly mixed premix. Finally, the process parameters of the twin-screw extruder are set, and the premix is ​​fed into the twin-screw extruder from the main feed inlet, while the flat glass fiber is fed into the twin-screw extruder from the side feed inlet. All material components are sheared, melt-blended, extruded, and granulated by the screw, which is easy to form into strands and suitable for large-scale production. The prepared high-glass fiber reinforced MXD6 material has excellent mechanical properties and gloss.

[0040] In a specific embodiment, the twin-screw extruder has a length-to-diameter ratio of 30:1-50:1, a rotational speed of 250-500 rpm, and an extrusion temperature of 200-280℃.

[0041] Based on a general inventive concept, the third aspect of the present invention provides an application of the low-float, high-flowability, high-glass fiber reinforced MXD6 material described in the first aspect in the manufacture of plastic parts for drones, automobiles, and electronic appliances.

[0042] In this application, the high glass fiber reinforced MXD6 material prepared by the above-mentioned formula and preparation method has stable performance, simple production process, easy to draw strands, can be mass-produced, and has good injection molding performance. It can be widely used in the injection molding of plastic parts in drones, automobiles, electronic appliances, etc., and is especially suitable for scenarios such as replacing steel with plastic.

[0043] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0044] Raw material sources for the examples and comparative examples: MXD6 Nylon: Grade 6000, relative viscosity 2.1, Mitsubishi Chemical Co., Ltd.

[0045] Flat fiberglass: aspect ratio of 3, chopped length of 3mm, fiber diameter of 10μm, grade ECS4F-03-570, Jushi Group.

[0046] Antioxidant: It is a compound of primary antioxidant and secondary antioxidant in a mass ratio of 1:1; Tianjin Lianlong New Material Co., Ltd., model RIANOX 168 / 1098.

[0047] Nucleating agent: Brügmann, Germany, model P22.

[0048] Anti-buoyancy fiber agent: Puzhan Industrial P180.

[0049] Lubricant PETs: Lonza, USA, PETS-P.

[0050] The heat resistant agent is Brügmann H320 from Germany.

[0051] Color masterbatch: Manufacturer is Jiucai, brand name is PA8183.

[0052] The preparation method of the self-made hyperbranched anti-buoyancy fiber agent includes the following steps: (1) 0.5 mol of isophenyltricarboxylic acid, 0.7 mol of p-phenylenediamine, 2.16 g of methylbenzenesulfonic acid (reaction catalyst), 250 g of xylene and 74 g of dimethylformamide (water-removing agent) were added to a reaction vessel equipped with a stirrer, condenser, water separator and thermometer. The mixture was purged with nitrogen three times under stirring. Then it was heated to 100-120 °C under nitrogen atmosphere and reacted for 30 min. Then it was heated to 120-170 °C and reacted for 24 h until no water was generated in the water separator. At this time, the end group of the hyperbranched compound is an amino group. After no water was generated in the water separator, the water-removing agent was removed under vacuum (to lower the boiling point) while it was hot. The product was taken out and cooled to obtain the first hyperbranched compound with an amino group at the end. (2) Add 0.5 mol of isophenyltricarboxylic acid, 0.7 mol of p-phenylenediamine, 2.16 g of methylbenzenesulfonic acid (reaction catalyst), 250 g of xylene and 74 g of dimethylformamide (water-removing agent) to a reaction vessel equipped with a stirrer, condenser, water separator and thermometer. Replace the mixture with nitrogen three times under stirring. Then heat the mixture to 100-120℃ under nitrogen atmosphere and react for 30 min. Then heat the mixture to 120-170℃ and react for 24 h until no water is generated in the water separator. At this time, the end group of the hyperbranched compound is an amino group. Introduce 10 mol of acrylic acid monomer and initiator. The initiator is benzoyl peroxide and the content is 0.2%-2% of the mass of acrylic acid monomer. After reacting at 70-90℃ for 3 h, remove the water-removing agent under vacuum (to lower the boiling point) while it is hot. Take out the product, cool it and grind it into powder to obtain the second hyperbranched compound grafted with polyacrylic acid. (3) Add 0.5 mol of isophenyltricarboxylic acid, 0.7 mol of p-phenylenediamine, 2.16 g of methylbenzenesulfonic acid (reaction catalyst), 250 g of xylene and 74 g of dimethylformamide (water-removing agent) to a reaction vessel equipped with a stirrer, condenser, water separator and thermometer. Replace with nitrogen three times under stirring, then heat to 100-120℃ under nitrogen atmosphere and react for 30 min, then heat to 120-170℃ and react for 24 h until no water is generated in the water separator. At this time, the end group of the hyperbranched compound is an amino group. Introduce 0.13 kg of self-made MXD6 with a degree of polymerization of (10-50) and a carboxyl group end group. React at 150-200℃ until no water is generated in the water separator. Remove the water-removing agent under vacuum (to lower the boiling point) while hot. Take out the product, cool and grind it to obtain the third hyperbranched compound modified by MXD6. (4) The first hyperbranched compound, the second hyperbranched compound and the third hyperbranched compound prepared above are mixed evenly in a mass ratio of 15:25:60 and kneaded to obtain granular hyperbranched anti-buoyancy fiber agent.

[0053] Since there are many comparative examples and implementation examples, and the blending modification methods are the same with only differences in specific proportions, they will not be described one by one. Representative specific proportion schemes are shown in Table 1: Table 1 Formulation ratios of high glass fiber reinforced MXD6 materials in Examples 1-6 and Comparative Examples 1-3 The formulations provided in Examples 1-6 and Comparative Examples 1-3 above were all prepared according to the experimental steps described below to prepare high glass fiber reinforced MXD6 materials: (1) Weigh each component of the raw materials according to the respective formulation ratios of the examples and comparative examples. Among them, MXD6 nylon needs to be dried at 100°C for 4 hours before weighing. (2) Mix the weighed MXD6 nylon, antioxidant, nucleating agent, heat resistant agent, lubricant, color masterbatch and hyperbranched anti-floating fiber agent to obtain a uniformly mixed premix; (3) Set the process parameters of the twin-screw extruder: The melt extrusion temperature of each section of the twin-screw extruder is: 240℃ for section 2, 270℃ for sections 3-5, 260℃ for sections 6-7, 250℃ for sections 8-10, the die temperature is 270℃-275℃, and the main machine speed is 350rpm. (4) The premix is ​​fed into the twin-screw extruder from the main feed inlet, and the flat glass fiber is fed into the twin-screw extruder from the side feed inlet. All material components are sheared, melt-blended, extruded and granulated by the screw to finally obtain high glass fiber reinforced MXD6 material.

[0054] The performance of the high glass fiber reinforced MXD6 materials prepared in Examples 1-6 and Comparative Examples 1-3 was tested, and the results are shown in Table 2. The specific test standards are as follows: (1) Tensile property testing: Test standard ISO 527; (2) Bending performance test: Test standard ISO 178; (3) Notched impact strength of simply supported beams: Test standard ISO 179; (4) Melt mass flow rate (MFR): Test standard ISO 1133, test temperature / load: 275℃ / 5kg; (5) Gloss test: The material is injection molded into a standard color plate, and the gloss of the color plate is tested using a gloss meter at an angle of 85°. (6) Appearance test: Inject the material into a standard color plate, continuously inject, take 16-20 molds, and evaluate the appearance grade; Appearance grade judgment (floating fiber degree): Grade 1 has no obvious floating fiber, Grade 2 has a small amount of floating fiber, Grade 3 has serious floating fiber, and Grade 4 has a large amount of floating fiber.

[0055] Table 2 Test Results The low-float, high-flowability, high-glass fiber reinforced MXD6 material product prepared by this invention was injection molded into ISO specimens. Tensile, flexural, and impact mechanical properties, as well as flowability, were tested according to ISO 527, ISO 178, ISO 179, and ISO 1133 standards. With a flat glass fiber content of 50%, the tensile strength was ≥290 MPa, the tensile modulus ≥20000 MPa, the flexural strength ≥390 MPa, the flexural modulus ≥19000 MPa, and the notched impact strength of a simply supported beam ≥13 J / m. 2 ISO2813 85° gloss ≥80, melt index (275℃ / 5kg) ≥50 g / 10min.

[0056] With a flat glass fiber content of 60%, the tensile strength is ≥300 MPa, the tensile modulus is ≥23000 MPa, the flexural strength is ≥420 MPa, the flexural modulus is ≥23000 MPa, and the notched impact strength of a simply supported beam is ≥15 J / m. 2 ISO2813 85° gloss ≥80, melt index (275℃ / 5kg) ≥50 g / 10min.

[0057] With a flat glass fiber content of 70%, the tensile strength is ≥250 MPa, the tensile modulus is ≥27000 MPa, the flexural strength is ≥370 MPa, the flexural modulus is ≥25000 MPa, and the notched impact strength of a simply supported beam is ≥10 J / m. 2 ISO2813 85° gloss ≥50, melt index (275℃ / 5kg) ≥50 g / 10min.

[0058] As can be seen from the experimental data in Tables 1 and 2, this application can stably prepare high glass fiber reinforced MXD6 materials with good mechanical properties; the test appearance diagrams of Examples 1-3 and Comparative Examples 1-2 are shown below. Figure 1 As shown, compared with commercially available conventional anti-floating fiber agents for aliphatic nylon, the formulation using the self-made hyperbranched anti-floating fiber agent of this application exhibits better tensile strength, flexural strength, impact strength, and a lower fiber floating rate. The high glass fiber reinforced MXD6 material prepared using the formulation of this application, in addition to possessing the stable mass production performance of a high glass fiber content MXD6 composite material, also features high modulus, excellent mechanical strength, good anti-floating fiber properties, high gloss, good flowability, and resistance to sticking to the feed inlet.

[0059] In summary, this application, through the synergistic effect of a self-made hyperbranched anti-floating fiber agent and flat glass fibers, not only enhances interfacial adhesion and reduces melt viscosity, but also suppresses the glass fiber floating rate. This makes it easy to draw strands, has good flowability, is not prone to sticking to the feed port, and is easy to injection mold when preparing high glass fiber reinforced MXD6 materials. It can be widely used in scenarios such as replacing steel with plastics, such as the manufacturing process of plastic parts in drones, automobiles, and electronic appliances.

[0060] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0062] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high glass fiber reinforced MXD6 material with low fiber float and high flow, characterized in that, By weight, it includes the following components: 20-45 parts MXD6 nylon, 50-70 parts flat glass fiber, 0.1-1 part antioxidant, 0.1-1 part nucleating agent, 0.1-1 part heat resistant agent, 0.1-1 part lubricant, 0.5-2 parts color masterbatch, and 0.6-2 parts hyperbranched anti-buoyancy fiber agent; The hyperbranched anti-buoyancy fiber agent is compounded and kneaded from a first hyperbranched compound, a second hyperbranched compound, and a third hyperbranched compound in a mass ratio of (10-20):(20-30):(50-70), wherein the first hyperbranched compound is a polyamide with an amino end group, the second hyperbranched compound is a polyamide grafted with polyacrylic acid, and the third hyperbranched compound is a polyamide modified with MXD6.

2. The low-fiber high-flow high-glass fiber-reinforced MXD6 material according to claim 1, characterized in that, The preparation method of the first hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine into a reaction vessel at a molar ratio of 1:1.4-1:3, reacting under nitrogen protection at 100-170°C until no anhydrous formation is generated, and removing the solvent to obtain a polyamide hyperbranched compound with amine end groups; The preparation method of the second hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 into a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, adding acrylic acid and an initiator, reacting at 70-90°C for 3 hours, removing the solvent, and obtaining a polyacrylic acid-grafted polyamide hyperbranched compound; wherein the molar ratio of isophthalic acid and acrylic acid is 1:3-1:20, and the amount of initiator added is 0.2-2% of the mass of acrylic acid; The preparation method of the third hyperbranched compound includes: adding isophthalic acid and p-phenylenediamine in a molar ratio of 1:1.4-1:3 into a reaction vessel, reacting under nitrogen protection at 100-170°C until anhydrous formation, adding MXD6 resin with carboxyl end groups, reacting at 150-200°C until anhydrous formation, removing the solvent, and obtaining the MXD6-modified polyamide hyperbranched compound; wherein the molar ratio of isophthalic acid to MXD6 resin is 1:1-1:

3.

3. The low-fiber high-flow high-glass fiber reinforced MXD6 material according to claim 1, characterized in that, The first hyperbranched compound, the second hyperbranched compound, and the third hyperbranched compound are in a mass percentage ratio of 15%:25%:60%.

4. The low-fiber high-flow high-glass fiber reinforced MXD6 material according to claim 1, characterized in that, The hyperbranched anti-buoyancy fiber agent has a number average molecular weight of 10,000-60,000 g / mol and a melting point of 50-200℃.

5. The low-fiber high-flow high-glass fiber reinforced MXD6 material according to claim 1, characterized in that, The MXD6 nylon has a relative viscosity of 2.0-2.2 and a melting point of 235-240℃.

6. The high glass fiber reinforced MXD6 material with low fiber float and high flowability according to claim 1, characterized in that, The flat glass fiber has a chopped length of 2-10 mm, a fiber diameter of 4-15 μm, and a flatness of 3:1-4:

1.

7. A method for preparing a high-glass fiber reinforced MXD6 material with low fiber float and high flowability, characterized in that, The preparation method includes the following steps: S1. Weigh out the raw material components according to the weight proportions of the low-float fiber, high-flowability, high-glass fiber reinforced MXD6 material as described in any one of claims 1-6; S2. The dried MXD6 nylon, antioxidant, nucleating agent, heat resistant agent, lubricant, color masterbatch, and hyperbranched anti-floating fiber agent are premixed together in a high-speed mixing tank to obtain a premix. S3. The premix is ​​fed into the twin-screw extruder through the main feed inlet, and the flat glass fiber is fed into the twin-screw extruder through the side feed inlet. All material components are sheared, melt-blended, extruded and granulated by the screw to obtain the high glass fiber reinforced MXD6 material.

8. The application of the low-float, high-flowability, high-glass fiber reinforced MXD6 material according to any one of claims 1-6 in the manufacture of plastic parts for drones, automobiles, and electronic appliances.

9. A plastic part, characterized in that, The plastic part is made of the low-float, high-flowability, high-glass fiber reinforced MXD6 material as described in any one of claims 1-6, and at least one auxiliary material.

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