Flame-retardant nylon 6 material as well as preparation method and application thereof
By treating glass fiber with modified silica sol and adding diatomaceous earth, the tensile strength and impact resistance of nylon 6 material were improved, solving the problem of insufficient strength of nylon 6 material and achieving a balance between high flame retardancy and high mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-04-14
AI Technical Summary
The tensile strength of Nylon 6 material is insufficient, and the interfacial bonding force between glass fiber and resin matrix is weak, which makes the material easy to separate under external force and cannot meet the mechanical performance requirements of high-end engineering applications.
Glass fibers are impregnated with modified silica sol to form a rough inorganic ceramic film, which increases the contact area between the fiber and the matrix. Hydrogen bonds are formed between the amino and imino groups and the amide groups in nylon 6. The combination of physical and chemical methods improves the interfacial bonding force. At the same time, diatomaceous earth is added to form a three-dimensional interpenetrating network, which enhances the impact resistance of the material.
It significantly improves the tensile strength and impact resistance of flame-retardant nylon 6 materials, achieving a balance between high flame retardancy and high mechanical properties, and meeting the needs of high-end engineering applications.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer composite materials technology, specifically to a flame-retardant nylon 6 material, its preparation method, and its application. Background Technology
[0002] Nylon 6, as a high-performance engineering plastic, features good heat resistance and easy processing and molding, and is widely used in electronics, automotive parts, and mechanical structural components. Especially in electronics and automotive parts, not only are good flame-retardant properties required, but also strong mechanical properties. In these applications, tensile strength directly reflects the material's ability to resist tensile failure under external forces. It is crucial not only for ensuring the product can withstand assembly stresses, vibration loads, and other external forces without deformation or breakage during assembly, transportation, and service, but also for guaranteeing product structural stability and extending service life.
[0003] Glass fiber, as a commonly used reinforcing filler, is widely used to improve the mechanical strength of nylon 6 materials. However, its application in nylon 6 systems still faces core technical challenges: the smooth and inert surface of glass fiber results in poor chemical compatibility with the nylon 6 resin matrix and weak interfacial bonding. This leads to easy interfacial separation between the fiber and the matrix under tensile, impact, or other external forces, sometimes even resulting in the fiber being pulled out directly. This not only fails to fully utilize the reinforcing effect of glass fiber but also leads to insufficient tensile strength in nylon 6 materials, making it difficult to meet the stringent mechanical performance requirements of high-end engineering applications. Therefore, a high-strength nylon 6 material is urgently needed. Summary of the Invention
[0004] This invention proposes a flame-retardant nylon 6 material, its preparation method, and its application, solving the problem of low strength of nylon 6 material in related technologies.
[0005] The technical solution of the present invention is as follows: This invention proposes a flame-retardant nylon 6 material, comprising the following components by weight: 100 parts flame-retardant nylon 6 and 30-35 parts pretreated glass fiber; The pretreated glass fiber is obtained by impregnating glass fiber with modified silica sol; The modified silica sol is obtained by modifying silica sol with N-β-aminoethyl-γ-aminopropyltrimethoxysilane.
[0006] As a further technical solution, the flame-retardant nylon 6 comprises the following raw materials in parts by weight: 90-100 parts of caprolactam, 14-18 parts of functional monomer, 1.5-2.5 parts of ring-opening agent, and 0.2-0.4 parts of stabilizer.
[0007] As a further technical solution, the functional monomer comprises the following components by weight: 8-10 parts of functional monomer A and 6-8 parts of functional monomer B; The functional monomer A is the flame retardant DDP; The functional monomer B includes one of ethylenediamine, propylenediamine, and hexamethylenediamine; Preferably, the functional monomer B is hexamethylenediamine.
[0008] As a further technical solution, the preparation method of the flame-retardant nylon 6 includes the following steps: S1. Polymerization: Caprolactam, ring-opening agent, stabilizer and functional monomer A and functional monomer B are mixed and reacted to obtain a special nylon polymer melt; S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into an extraction tower, and the extractable substances in the slices are removed by a water countercurrent extraction process. After drying, the flame-retardant nylon 6 is obtained.
[0009] This invention utilizes a one-step in-situ polymerization technique to achieve uniform dispersion and chemical bonding of flame retardants at the molecular chain level. This process significantly shortens the production cycle and reduces overall manufacturing costs. The resulting nylon 6 material exhibits excellent intrinsic flame retardancy, achieving V-0 flame retardancy rating with minimal flame retardant usage. This successfully overcomes the problem of decreased mechanical properties caused by large amounts of flame retardant added in traditional flame retardant modification, achieving a perfect balance between high flame retardancy and high mechanical properties. Furthermore, the resulting flame-retardant nylon 6 has good spinnability and can be used for spinning and other textile preparations, demonstrating high application value.
[0010] As a further technical solution, the method for preparing the pretreated glass fiber includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, hydrochloric acid solution was added, and the mixture was stirred to react, thus obtaining a modified silica sol. A2. After desizing, the glass fiber is immersed in modified silica sol for impregnation treatment and then dried to obtain pretreated glass fiber.
[0011] As a further technical solution, the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane to tetraethyl orthosilicate is 0.2~0.4:1.
[0012] As a further technical solution, the molar ratio of tetraethyl orthosilicate to ethanol is 1:4~5; Preferably, the molar ratio of tetraethyl orthosilicate to ethanol is 1:4.
[0013] As a further technical solution, the temperature of the stirring reaction is 40~50℃, and the stirring reaction time is 4~5h.
[0014] As a further technical solution, the immersion time during the immersion treatment is 15-20 minutes.
[0015] As a further technical solution, the flame-retardant nylon 6 material further includes the following components by weight: 1.4-5 parts diatomaceous earth and 1-2 parts compatibilizer.
[0016] In this invention, the impact resistance of flame-retardant nylon 6 material is improved by using pretreated glass fibers and diatomaceous earth in combination. After impregnation with modified silica sol, a transition layer containing organosilicon groups is formed on the surface of the glass fibers. When the material is impacted, this transition layer can absorb part of the impact energy, avoiding stress concentration and brittle fracture caused by direct contact between rigid glass fibers and rigid matrix. The pretreated glass fibers provide a load-bearing skeleton, and diatomaceous earth particles fill the gaps in the skeleton, forming a three-dimensional interpenetrating network that combines rigidity and toughness. Furthermore, diatomaceous earth and silica sol have similar chemical compositions and surface energies, exhibiting excellent compatibility. This achieves uniform dispersion of the filler and strong bonding at the interface, thereby synergistically improving the impact resistance of flame-retardant nylon 6 material.
[0017] As a further technical solution, the mass ratio of the pretreated glass fiber to diatomaceous earth is 9~13:1.
[0018] As a further technical solution, the ring-opening agent is demineralized water.
[0019] As a further technical solution, the stabilizer includes one or both of antioxidant 1010 and antioxidant 1098.
[0020] As a further technical solution, the compatibilizer includes ethylene-methyl acrylate copolymer.
[0021] The present invention also proposes a method for preparing flame-retardant nylon 6 material, comprising the following steps: mixing the components, extruding, granulating, and obtaining the flame-retardant nylon 6 material.
[0022] This invention also proposes the application of a flame-retardant nylon 6 material or a method for preparing a flame-retardant nylon 6 material in engineering plastics.
[0023] The working principle and beneficial effects of this invention are as follows: In this invention, the tensile strength of flame-retardant nylon 6 material is improved by adding N-β-aminoethyl-γ-aminopropyltrimethoxysilane-modified silica sol to impregnate glass fibers. The smooth surface of the glass fibers results in weak mechanical adhesion to the resin. After the silica sol dries and cures on the glass fiber surface, it forms a rough inorganic ceramic film. This rough film significantly increases the contact area between the glass fibers and the nylon 6 matrix, preventing the fibers from being pulled out of the matrix, thus significantly improving the interfacial bonding force through physical means. Furthermore, when the glass fibers are impregnated in the modified silica sol, their surface acquires amino and imino groups. These amino and imino groups can form hydrogen bonds with the amide groups in nylon 6, thereby significantly improving the interfacial bonding force through chemical means. This dual effect greatly enhances the interfacial bonding force, allowing tensile loads to be effectively transferred to the glass fibers, thus significantly improving the tensile strength of the material. Detailed Implementation
[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0025] In the following examples and comparative examples, the glass fiber is chopped glass fiber with a length of 4.5 mm and a diameter of 11 μm; the diatomaceous earth is 325 mesh; and the ethylene-methyl acrylate copolymer is model AC1218.
[0026] Example 1 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 30 parts pretreated glass fiber, and 1 part ethylene-methyl acrylate copolymer; The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain a modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.2:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for 20 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 90 parts caprolactam, 8 parts flame retardant DDP, 6 parts hexamethylenediamine, 1.5 parts deionized water, and 0.2 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0027] Example 2 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 35 parts pretreated glass fiber, and 2 parts ethylene-methyl acrylate copolymer; The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.4:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0028] Example 3 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 32 parts pretreated glass fiber, and 1.5 parts ethylene-methyl acrylate copolymer; The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.3:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for 20 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 95 parts caprolactam, 9 parts flame retardant DDP, 7 parts hexamethylenediamine, 2 parts desalinated water, and 0.3 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0029] Example 4 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 31.5 parts pretreated glass fiber, 3.5 parts diatomaceous earth, and 2 parts ethylene-methyl acrylate copolymer. The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.4:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, diatomaceous earth, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0030] Example 5 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 32.5 parts pretreated glass fiber, 2.5 parts diatomaceous earth, and 2 parts ethylene-methyl acrylate copolymer. The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.4:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, diatomaceous earth, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0031] Example 6 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 30 parts pretreated glass fiber, 5 parts diatomaceous earth, and 2 parts ethylene-methyl acrylate copolymer. The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.4:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, diatomaceous earth, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0032] Example 7 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 33.6 parts pretreated glass fiber, 1.4 parts diatomaceous earth, and 2 parts ethylene-methyl acrylate copolymer; The method for preparing pretreated glass fibers includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, and the pH of the system was adjusted to 4 by adding 0.3 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 40 °C for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol was 0.4:1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, diatomaceous earth, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0033] Comparative Example 1 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 35 parts pretreated glass fiber, and 2 parts ethylene-methyl acrylate copolymer. The method for preparing pretreated glass fibers includes the following steps: A1. Disperse silane coupling agent KH-550 and tetraethyl orthosilicate in anhydrous ethanol, add 0.3 mol / L hydrochloric acid aqueous solution to adjust the pH of the system to 4, stir and react at 40℃ for 5 h to obtain modified silica sol, wherein the molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane, tetraethyl orthosilicate and anhydrous ethanol is 0.4:1:4; A2. Place the glass fiber in a muffle furnace, calcine it at 400℃ to remove the slurry, then immerse it in modified silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0034] Comparative Example 2 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 35 parts pretreated glass fiber, and 2 parts ethylene-methyl acrylate copolymer. The method for preparing pretreated glass fibers includes the following steps: A1. Tetraethyl orthosilicate was dispersed in anhydrous ethanol, and 0.3 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the system to 4. The mixture was stirred at 40°C for 5 h to obtain silica sol, wherein the molar ratio of tetraethyl orthosilicate to anhydrous ethanol was 1:4. A2. Place the glass fiber in a muffle furnace, calcine it at 400°C to remove the slurry, then immerse it in silica sol for impregnation treatment for 15 minutes, and dry it to obtain pretreated glass fiber. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, pretreated glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0035] Comparative Example 3 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 35 parts glass fiber, and 2 parts ethylene-methyl acrylate copolymer; Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, glass fiber, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0036] Comparative Example 4 A flame-retardant nylon 6 material comprises the following components in parts by weight: 100 parts flame-retardant nylon 6, 35 parts diatomaceous earth, and 2 parts ethylene-methyl acrylate copolymer. Flame-retardant nylon 6 comprises the following components by weight: 100 parts caprolactam, 10 parts flame retardant DDP, 8 parts hexamethylenediamine, 2.5 parts deionized water, and 0.4 parts antioxidant 1010; A method for preparing flame-retardant nylon 6 material includes the following steps: S1. Polymerization: Caprolactam, demineralized water, antioxidant 1010, flame retardant DDP, and hexamethylenediamine are mixed and reacted in a polymerization reactor at a reaction temperature of 245℃ to obtain a special nylon polymer melt. S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into the extraction tower, and the extractable substances in the slices are removed by water countercurrent extraction process. After drying, flame-retardant nylon 6 is obtained. S4. Mix flame-retardant nylon 6, diatomaceous earth, and ethylene-methyl acrylate copolymer, extrude, and granulate to obtain flame-retardant nylon 6 material.
[0037] Experimental Example 1 Tensile strength: The flame-retardant nylon 6 materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested for tensile strength according to the method specified in GB / T 1040.1-2018 "Determination of tensile properties of plastics - Part 1: General". The thickness of the specimen was 4 mm, and the speed of the testing machine was 5 mm / min. The test results are shown in Table 1. Table 1. Test results of tensile strength
[0038] By comparing the data of Examples 1-3 and Comparative Examples 1-3, the tensile strength of the flame-retardant nylon 6 materials prepared by adding N-β-aminoethyl-γ-aminopropyltrimethoxysilane-modified silica sol impregnation treatment to glass fibers in Examples 1-3 was greater than that in Comparative Examples 1-3. This indicates that the tensile strength of the flame-retardant nylon 6 materials can be improved by adding N-β-aminoethyl-γ-aminopropyltrimethoxysilane-modified silica sol impregnation treatment to glass fibers.
[0039] Experiment Example 2 Impact resistance: The flame-retardant nylon 6 materials prepared in Examples 2, 4-7, and Comparative Example 4 were tested for notched impact strength of simply supported beams according to the method specified in GB / T1043.1-2008 "Determination of impact properties of simply supported beams of plastics - Part 1: Non-instrumental impact testing". The specimens were type 1 specimens with type A notches. The test results are shown in Table 2. Table 2 Test results of impact resistance
[0040] By comparing the data from Examples 2, 4-7, and Comparative Example 4, it was found that the notched impact strength of the flame-retardant nylon 6 material prepared by using pretreated glass fiber and diatomaceous earth in Examples 4-7 was greater than that in Examples 2 and Comparative Example 4. This indicates that the impact resistance of the flame-retardant nylon 6 material can be improved by using pretreated glass fiber and diatomaceous earth in combination. By comparing the data from Examples 4-7, it was found that the impact resistance of the flame-retardant nylon 6 material in Examples 4-5 can be further improved by further optimizing the mass ratio of pretreated glass fiber to diatomaceous earth to 9-13:1.
[0041] Experimental Example 3 Flame retardancy: The vertical flammability of the nylon 6 samples prepared in Examples 1-3 was tested according to Test Method B in GB / T 2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Methods". The sample thickness was 3 mm. The test results are shown in Table 3. Table 3. Test results of flame retardancy
[0042] The data in Table 3 show that the intrinsic flame retardant rating of the flame-retardant nylon 6 prepared in Examples 1-3 of the present invention all reached V-0, indicating good flame retardancy.
[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A flame-retardant nylon 6 material, characterized in that, The composition includes the following components in parts by weight: 100 parts flame-retardant nylon 6 and 30-35 parts pretreated glass fiber; The pretreated glass fiber is obtained by impregnating glass fiber with modified silica sol; The modified silica sol is obtained by modifying silica sol with N-β-aminoethyl-γ-aminopropyltrimethoxysilane.
2. The flame-retardant nylon 6 material according to claim 1, characterized in that, The flame-retardant nylon 6 comprises the following raw materials in parts by weight: 90-100 parts caprolactam, 14-18 parts functional monomer, 1.5-2.5 parts ring-opening agent, and 0.2-0.4 parts stabilizer.
3. The flame-retardant nylon 6 material according to claim 2, characterized in that, The functional monomer comprises the following components in parts by weight: 8-10 parts of functional monomer A and 6-8 parts of functional monomer B; The functional monomer A is the flame retardant DDP; The functional monomer B includes one of ethylenediamine, propylenediamine, and hexamethylenediamine.
4. The flame-retardant nylon 6 material according to claim 3, characterized in that, The preparation method of the flame-retardant nylon 6 includes the following steps: S1. Polymerization: Caprolactam, ring-opening agent, stabilizer and functional monomer A and functional monomer B are mixed and reacted to obtain a special nylon polymer melt; S2. Pelletizing: The special nylon polymer melt is filtered and sent to an underwater pelletizing system. After being extruded by a casting belt and cooled and solidified by cooling water, it is sliced. S3. Extraction: The slices are fed into an extraction tower, and the extractable substances in the slices are removed by a water countercurrent extraction process. After drying, the flame-retardant nylon 6 is obtained.
5. The flame-retardant nylon 6 material according to claim 1, characterized in that, The method for preparing the pretreated glass fiber includes the following steps: A1. N-β-aminoethyl-γ-aminopropyltrimethoxysilane and tetraethyl orthosilicate were dispersed in anhydrous ethanol, hydrochloric acid solution was added, and the mixture was stirred to react, thus obtaining a modified silica sol. A2. After desizing, the glass fiber is immersed in modified silica sol for impregnation treatment and then dried to obtain pretreated glass fiber.
6. The flame-retardant nylon 6 material according to claim 5, characterized in that, The molar ratio of N-β-aminoethyl-γ-aminopropyltrimethoxysilane to tetraethyl orthosilicate is 0.2~0.4:
1.
7. The flame-retardant nylon 6 material according to claim 5, characterized in that, The temperature of the stirring reaction is 40~50℃, and the stirring reaction time is 4~5h; The immersion time during the immersion treatment is 15-20 minutes.
8. The flame-retardant nylon 6 material according to claim 1, characterized in that, The flame-retardant nylon 6 material further includes the following components by weight: 1.4-5 parts diatomaceous earth and 1-2 parts compatibilizer; The mass ratio of the pretreated glass fiber to diatomaceous earth is 9~13:
1.
9. A method for preparing a flame-retardant nylon 6 material, used to prepare the flame-retardant nylon 6 material according to any one of claims 1 to 8, characterized in that, Includes the following steps: The components are mixed, extruded, and granulated to obtain the flame-retardant nylon 6 material.
10. The application of a flame-retardant nylon 6 material according to any one of claims 1 to 8 or a flame-retardant nylon 6 material prepared by the preparation method according to claim 9 in engineering plastics.