Flame-retardant master batch for green and environment-friendly polyamide 66 fiber as well as preparation method and application of flame-retardant master batch

Abstract

The invention discloses a flame-retardant master batch for green and environment-friendly polyamide 66 fibers as well as a preparation method and application of the flame-retardant master batch. The flame-retardant master batch provided by the invention is prepared from the following raw materials in parts by weight: 47 to 81 parts of PA66 resin, 5 to 15 parts of a phosphazene flame retardant, 8 to 20 parts of micron-sized MCA, 5 to 15 parts of ADP and 1 to 3 parts of a processing aid. The polyamide 66 flame-retardant master batch provided by the invention is halogen-free and flame-retardant, and has relatively high flame-retardant efficiency and excellent spinnability, and a polyamide 66 fiber material prepared from the polyamide 66 flame-retardant master batch has relatively high flame-retardant efficiency and excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardant polymer materials, and specifically relates to a green and environment-friendly flame retardant masterbatch for polyamide 66 fiber and a preparation method and application thereof. Background Art

[0002] Polyamide 66, professionally known as polyhexamethylene adipamide, commonly known as nylon 66 (PA66), is a thermoplastic resin, generally made by polycondensation of adipic acid and hexamethylenediamine. Polyamide 66 (PA66) is widely used due to its high mechanical strength and good heat resistance, but its flammability limits its application in scenarios with strict flame retardancy requirements, so it needs to be modified by adding flame retardants.

[0003] Traditional halogen flame retardants have been gradually phased out due to environmental toxicity issues, and halogen-free flame retardant systems (such as phosphorus and nitrogen) need to be compounded to achieve efficient flame retardancy. However, the phosphorus-nitrogen compound system in the existing technology often has problems such as insufficient flame retardancy efficiency, poor compatibility with the matrix, and large loss of mechanical properties.

[0004] Although existing studies have shown that by selecting suitable phosphazene compounds and hypophosphite flame retardants, the flame retardant efficiency of polyamide 6 materials can be improved and the problems of poor compatibility between traditional flame retardants and the matrix and poor mechanical properties can be solved, there are significant differences between polyamide 66 and polyamide 6 in structure and heat resistance, physical properties (such as strength, rigidity, wear resistance and oil resistance) and processing performance. Therefore, it is necessary to find a low-cost and simple process modification method suitable for the material based on the characteristics of polyamide 66 itself. Summary of the invention

[0005] In view of the above problems, the present invention provides a green and environmentally friendly flame retardant masterbatch for polyamide 66 fiber and a preparation method and application thereof.

[0006] In a first aspect, the present invention provides a flame retardant masterbatch, which is prepared from raw materials including the following parts by weight: 47-81 parts by weight of PA66 resin, 5-15 parts by weight of phosphazene flame retardant, 8-20 parts by weight of micron-grade MCA, 5-15 parts by weight of ADP, and 1-3 parts by weight of processing aid.

[0007] The present invention uses phosphazene compounds (Phosphazene), micron-sized melamine cyanurate (MCA) and diethyl aluminum phosphinate (ADP) as a flame retardant system, wherein the phosphazene compounds have high thermal stability and phosphorus-nitrogen synergistic flame retardant effect, but the cost of using them alone is relatively high, while the micron-sized MCA has a small particle size and good dispersibility, and can improve the gas phase flame retardant effect. ADP, as a phosphorus-based flame retardant, promotes carbonization in the condensed phase. By forming a "gas-solid" synergy between the phosphazene flame retardant (gas phase flame retardant) and ADP (condensed phase carbonization), combined with micron MCA (diluting combustible gas and promoting carbon layer densification), multi-mechanism flame retardancy is achieved. The prepared flame retardant masterbatch has the characteristics of high efficiency flame retardancy, low smoke and non-toxicity, and excellent mechanical properties, and is suitable for the fields of polyamide fiber fabrics, electronic appliances, new energy vehicle components, etc.

[0008] The phosphazene flame retardant is hexaphenoxy cyclotriphosphazene.

[0009] The particle size of the micron-sized MCA is ≤5 μm.

[0010] The processing aid includes one or more of a lubricant, an antioxidant or a silane coupling agent; The lubricant is EBS; The antioxidant is antioxidant 1098; The silane coupling agent is KH550.

[0011] In a second aspect, the present invention provides a method for preparing the flame retardant masterbatch, comprising the following steps: S1, adding micron-sized MCA, ADP and silane coupling agent into a solvent, stirring, and drying to obtain a surface-modified flame retardant; S2. Mix the surface modified flame retardant, phosphazene flame retardant, PA66 resin and other raw materials, extrude and granulate them to obtain a flame retardant masterbatch.

[0012] The present invention improves the interfacial compatibility of MCA, ADP and PA66 resin through surface modification, reduces the loss of mechanical properties, thereby achieving the synergistic compounding of the three, and further improving the flame retardant efficiency and mechanical properties of the flame retardant masterbatch.

[0013] In step S1, the solvent is selected from ethanol.

[0014] In step S1, the stirring temperature is 75-85° C. and the stirring time is 15 min.

[0015] In step S2, the extrusion granulation adopts a twin-screw extrusion process; the process parameters of the twin-screw extrusion process are: The temperature of the first temperature zone is 200-220℃; the temperature of the second temperature zone is 245-260℃; the temperature of the third temperature zone is 255-270℃; the temperature of the fourth temperature zone is 255-270℃; the temperature of the fifth temperature zone is 255-270℃; the temperature of the sixth temperature zone is 260-280℃; the temperature of the seventh temperature zone is 260-280℃; the temperature of the eighth temperature zone is 255-270℃; the temperature of the ninth temperature zone is 250-270℃; the temperature of the tenth temperature zone is 250-270℃; the temperature of the eleventh temperature zone is 265-285℃; the temperature of the twelfth temperature zone is 265-285℃; the temperature of the head temperature zone is 270-290℃; The main engine speed of the screw shearing in the twin-screw extrusion process is 180-260r / min.

[0016] In a third aspect, the present invention provides a polyamide 66 fiber, comprising the flame retardant masterbatch.

[0017] The polyamide 66 fiber is a civilian fully drawn silk fiber.

[0018] In a fourth aspect, the present invention provides the use of the polyamide 66 fiber in the preparation of polyamide fiber fabrics, electronic appliances, and new energy vehicle components.

[0019] In a fifth aspect, the present invention provides a polyamide fiber fabric, which is made using the above-mentioned polyamide 66 fiber.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. The polyamide 66 flame retardant masterbatch provided by the present invention has the following advantages: (1) it is halogen-free flame retardant, complies with RoHS and REACH standards, has low smoke density and no toxic gas release during combustion; (2) it has high flame retardant efficiency and can achieve good flame retardant effect at a relatively low addition amount; (3) it has excellent spinnability, especially in polyamide 66 civilian filament fibers; (4) it has low cost and greatly reduces the addition amount of phosphazene flame retardant while ensuring flame retardant efficiency and mechanical properties.

[0021] 2. The polyamide 66 fiber material provided by the present invention has high flame retardant efficiency and excellent mechanical properties. DETAILED DESCRIPTION

[0022] Unless otherwise specified, the resins, additives, etc. used in the following examples can be obtained from commercial sources.

[0023] The experimental methods in the following examples are all conventional methods unless otherwise specified.

[0024] The relative viscosity analysis of the masterbatch was conducted using an IDS-4-4-0-4 automatic viscosity tester purchased from Hangzhou Zhenyue Technology Co., Ltd. / Shanghai Bingjing Instrument Equipment Co., Ltd.

[0025] The fiber vertical combustion test was conducted using a UL94 horizontal vertical combustion instrument of model JL-CZF-5 purchased from Nanjing Jionglei Instrument Equipment Co., Ltd.

[0026] The fiber vertical LOI test was conducted using a limiting oxygen index tester model 11309 purchased from Fire Testing Technology Ltd.

[0027] The fiber fineness test was conducted using a yarn length measuring machine of model YG086 purchased from Wenzhou Darong Textile Instrument Co., Ltd.

[0028] The fiber breaking strength and fiber breaking elongation tests were conducted using a 1kN Zwicki fiber fabric universal testing machine purchased from Zwick Roy Company.

[0029] The reagents used in the following examples and comparative examples are as follows: PA66 resin: purchased from Huafeng Group Co., Ltd.

[0030] Phosphazene flame retardant: hexaphenoxy cyclotriphosphazene (SPB 100) was purchased from Otsuka Chemical Co., Ltd., Japan.

[0031] Micron MCA: melamine cyanurate, micron grade, purchased from Jinan Taixing Fine Chemical Co., Ltd.

[0032] ADP: aluminum diethylphosphinate, purchased from Zhejiang Xinhua Chemical Industry Co., Ltd.

[0033] EBS: ethylene bisstearamide, purchased from Clariant Chemicals (China) Co., Ltd.

[0034] Antioxidant 1098: N,N'-(hexane-1,6-diyl)bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], purchased from Tianjin Lianlong New Materials Co., Ltd.

[0035] KH550 (coupling agent): purchased from Guangzhou Zhongjie Chemical Technology Co., Ltd.

[0036] Example 1 A flame retardant masterbatch for polyamide 66 fiber is prepared from the following raw materials in mass fraction: PA66 resin: 65%; phosphazene flame retardant: 10%; micron MCA (particle size 5 μm): 12%; ADP: 10%; EBS: 1.5%; antioxidant 1098: 1%; KH550 (coupling agent): 0.5%.

[0037] The preparation of the flame retardant masterbatch is carried out according to the following steps: (1) Modify micron MCA and ADP with KH550 ethanol solution and then dry; (2) premixing the dried micronized MCA, ADP and other raw materials for 15 minutes to obtain a mixed material; (3) The mixed material is extruded into granules through a twin-screw extruder to obtain a flame retardant masterbatch.

[0038] Example 2 A flame retardant masterbatch for polyamide 66 fiber is prepared from the following raw materials in mass fraction: PA66 resin: 65%; phosphazene flame retardant: 10%; micron MCA (particle size 5 μm): 7%; ADP: 15%; EBS: 1.5%; antioxidant 1098: 1%; KH550 (coupling agent): 0.5%.

[0039] The preparation of the flame retardant masterbatch is carried out according to the following steps: (1) Modify micron MCA and ADP with KH550 ethanol solution and then dry; (2) premixing the dried micronized MCA, ADP and other raw materials for 15 minutes to obtain a mixed material; (3) The mixed material is extruded into granules through a twin-screw extruder to obtain a flame retardant masterbatch.

[0040] Example 3 A flame retardant masterbatch for polyamide 66 fiber is prepared from the following raw materials in mass fraction: PA66 resin: 65%; phosphazene flame retardant: 5%; micron MCA (particle size 5 μm): 12%; ADP: 15%; EBS: 1.5%; antioxidant 1098: 1%; KH550 (coupling agent): 0.5%.

[0041] The preparation of the flame retardant masterbatch is carried out according to the following steps: (1) Modify micron MCA and ADP with KH550 ethanol solution and then dry; (2) premixing the dried micronized MCA, ADP and other raw materials for 15 minutes to obtain a mixed material; (3) The mixed material is extruded into granules through a twin-screw extruder to obtain a flame retardant masterbatch.

[0042] Comparative Example 1 A flame retardant masterbatch for polyamide 66 fiber is prepared from the following raw materials in mass fraction: PA66 resin: 65%; micron MCA (particle size 5 μm): 32%; EBS: 1.5%; antioxidant 1098: 1%; KH550 (coupling agent): 0.5%.

[0043] The preparation of the flame retardant masterbatch is carried out according to the following steps: (1) Modify the micron MCA with KH550 ethanol solution and then dry it; (2) premixing the dried micronized MCA and other raw materials for 15 minutes to obtain a mixed material; (3) The mixed material is extruded into granules through a twin-screw extruder to obtain a flame retardant masterbatch.

[0044] Comparative Example 2 A flame retardant masterbatch for polyamide 66 fiber is prepared from the following raw materials in mass fraction: PA66 resin: 65%; ADP: 32%; EBS: 1.5%; antioxidant 1098: 1%; KH550 (coupling agent): 0.5%.

[0045] The preparation of the flame retardant masterbatch is carried out according to the following steps: (1) Modify ADP with KH550 ethanol solution and then dry it; (2) premixing the dried ADP and other raw materials for 15 minutes to obtain a mixed material; (3) The mixed material is extruded into granules through a twin-screw extruder to obtain a flame retardant masterbatch.

[0046] Example 4 A polyamide 66 fiber is prepared by using the flame retardant masterbatch obtained in the above examples 1-3 and comparative examples 1-2 to respectively prepare polyamide 66 civilian fully drawn silk fibers with a direct spinning specification of 50D / 34F.

[0047] Test Example 1: Flame retardant efficiency of PA66 fibers made from various flame retardant masterbatches The flame retardant efficiency of polyamide 66 civilian fully drawn silk fibers prepared from the flame retardant masterbatches obtained in Examples 1-3 and Comparative Examples 1-2 was tested.

[0048] The addition ratio of the masterbatch and the LOI value of each embodiment and comparative example are shown in Table 1.

[0049] Table 1 Addition ratio and LOI value of flame retardant masterbatch for polyamide 66 fiber

[0050] As shown in Table 1, as the addition ratio of flame retardant masterbatch increases, the LOI index of polyamide 66 fiber will increase accordingly. The effects of Example 1, Example 2, and Example 3 are better than those of Comparative Example 1 and Comparative Example 2, among which Example 2 has the highest effect. This indicates that the flame retardant effect of the composite flame retardant is better than that of a single component flame retardant.

[0051] Test Example 2: Physical properties of fibers The fineness, breaking strength and breaking elongation of the polyamide 66 civilian fully drawn filaments prepared from the flame retardant masterbatches obtained in Test Examples 1-3 and Comparative Examples 1-2 are shown in Table 2 for details.

[0052] Table 2 Physical properties of cool polyamide 66 civilian filament fibers

[0053] It can be seen from Table 2 that the fiber breaking strength and breaking elongation of Example 1, Example 2 and Example 3 are better than those of Comparative Example 1 and Comparative Example 2. This indicates that the addition of the composite flame retardant has little effect on the physical properties of the fiber.

[0054] It can be seen from the results in Table 1 and Table 2 that the flame retardant masterbatch provided by the present invention can improve the flame retardant properties of PA66 fiber while the fiber can also maintain good mechanical strength.

[0055] Comparative Example 3 A flame retardant masterbatch for polyamide 66 fiber, which differs from Example 2 in that the micron-grade MCA is replaced by a material of the same type, specifically melamine polyphosphate.

[0056] The PA66 fiber was prepared in the same manner as in Example 2.

[0057] The results show that when the addition ratio of the flame retardant masterbatch in this comparative example is 5%, the LOI index of the PA66 fiber obtained is 29%, the fineness is 50D / 34F, the breaking strength is 5.87cN / dtex, and the breaking elongation is 21.58%, indicating that although its flame retardant properties are improved, the mechanical properties are difficult to maintain; when the addition ratio is 10%, the LOI index of the PA66 fiber obtained is 32%.

[0058] Comparative Example 4 A flame retardant masterbatch for polyamide 66 fiber, which differs from Example 2 in that ADP is replaced by other materials of the same flame retardant, specifically BEP-13N, purchased from Sichuan Fine Chemical Research and Design Institute Co., Ltd.

[0059] The PA66 fiber was prepared in the same manner as in Example 2.

[0060] The results show that when the addition ratio of the flame retardant masterbatch in this comparative example is 5%, the LOI index of the PA66 fiber prepared is 28%, the fineness is 50D / 34F, the breaking strength is 5.76cN / dtex, and the breaking elongation is 20.89%, indicating that although its flame retardant properties are improved, the mechanical properties are difficult to maintain; when the addition ratio is 10%, the LOI index of the PA66 fiber prepared is 31%.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A flame retardant masterbatch, prepared from the following raw materials in parts by weight: 47-81 parts by weight of PA66 resin, 5-15 parts by weight of phosphazene flame retardant, 8-20 parts by weight of micron-grade MCA, 5-15 parts by weight of ADP, and 1-3 parts by weight of processing aid.

2. The flame retardant masterbatch according to claim 1, characterized in that: The phosphazene flame retardant is hexaphenoxy cyclotriphosphazene.

3. The flame retardant masterbatch according to claim 1 or 2, characterized in that: The particle size of the micron-sized MCA is ≤5 μm.

4. The flame retardant masterbatch according to any one of claims 1 to 3, characterized in that: The processing aid includes one or more of a lubricant, an antioxidant or a silane coupling agent; The lubricant is EBS; The antioxidant is antioxidant 1098; The silane coupling agent is KH550.

5. The method for preparing the flame retardant masterbatch according to any one of claims 1 to 4, comprising the following steps: S1, adding micron-sized MCA, ADP and silane coupling agent into a solvent, stirring, and drying to obtain a surface-modified flame retardant; S2. Mix the surface modified flame retardant, phosphazene flame retardant, PA66 resin and other raw materials, extrude and granulate them to obtain a flame retardant masterbatch.

6. The preparation method according to claim 5, characterized in that: In step S1, the solvent is selected from ethanol; The stirring temperature is 75-85°C.

7. The preparation method according to claim 5 or 6, characterized in that: In step S2, the extrusion granulation adopts a twin-screw extrusion process; The process parameters of the twin-screw extrusion process are: The temperature of the first temperature zone is 200-220℃; the temperature of the second temperature zone is 245-260℃; the temperature of the third temperature zone is 255-270℃; the temperature of the fourth temperature zone is 255-270℃; the temperature of the fifth temperature zone is 255-270℃; the temperature of the sixth temperature zone is 260-280℃; the temperature of the seventh temperature zone is 260-280℃; the temperature of the eighth temperature zone is 255-270℃; the temperature of the ninth temperature zone is 250-270℃; the temperature of the tenth temperature zone is 250-270℃; the temperature of the eleventh temperature zone is 265-285℃; the temperature of the twelfth temperature zone is 265-285℃; the temperature of the head temperature zone is 270-290℃; The main engine speed of the screw shearing in the twin-screw extrusion process is 180-260r / min.

8. A polyamide 66 fiber, made from the flame retardant masterbatch according to any one of claims 1 to 4.

9. Use of the polyamide 66 fiber according to claim 8 in the preparation of polyamide fiber fabrics, electronic appliances, and new energy vehicle parts.

10. A polyamide fiber fabric, made from the polyamide 66 fiber according to claim 8.

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