A polyamide composition and its preparation method and application

Abstract

The present invention discloses a polyamide composition, its preparation method, and application. The polyamide composition comprises the following components, calculated by weight: 28-80 parts of polyamide resin; 10-42 parts of glass fiber; 10-30 parts of organophosphorus flame retardant; 0.5-3.5 parts of anhydrous zinc borate; and 0.5-5 parts of flaky filler. The polyamide resin has a terminal amino group content of not less than 38 mmol / kg; the anhydrous zinc borate has a D50 of 3-10 μm; and the glass fiber has an average diameter of 9-15 μm. By selecting a polyamide resin with a specific terminal amino group content as the base resin and adding anhydrous zinc borate and flaky filler, the present invention can form a carbon layer structure capable of resisting airflow during combustion, thereby providing the polyamide composition with better performance.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastics, and more particularly to a polyamide composition, a preparation method and an application thereof. Background Art

[0002] Polyamide resin materials are widely used in sports equipment, electronic appliances, household appliances, rail transit, and other fields due to their good heat and solvent resistance, excellent mechanical properties, and good processing properties. Currently, halogen-free flame retardants used in glass fiber reinforcement mainly include two basic systems: one is red phosphorus, and the other is phosphorus-nitrogen flame retardant systems. Among them, phosphorus-nitrogen flame retardant nylon has the wider applicability. With the rapid development of the new energy industry, higher requirements are placed on materials involved in the "three electric" systems of automobiles. One test that is currently gaining increasing attention is material testing. Compared with the ordinary UL94 combustion test, this test requires materials to have a higher flame retardancy level. However, ordinary flame retardant nylon systems cannot meet this test requirement. This limits its application in the field of new energy electronic control.

[0003] Therefore, there is a need in the art to develop a polyamide composition having good flame retardant effect and good performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a polyamide composition in order to overcome the defects or deficiencies in the above-mentioned prior art, wherein the polyamide composition has better performance and tensile strength.

[0005] Another object of the present invention is to provide a method for preparing the polyamide composition.

[0006] Another object of the present invention is to provide applications of the polyamide composition.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions:

[0008] A polyamide composition comprising the following components calculated in parts by weight:

[0009]

[0010] The terminal amino group content in the polyamide resin is not less than 38 mmol / kg; the D50 of the anhydrous zinc borate is 3 to 10 μm; and the average diameter of the glass fiber is 9 to 15 μm.

[0011] The present invention provides a polyamide composition. The polyamide composition is prepared by selecting a polyamide resin having a terminal amino group content of not less than 38 mmol / kg and adding anhydrous zinc borate and a lamellar filler therein. The polyamide composition can form a carbon layer structure with a certain structural strength during combustion, and can resist damage to the carbon layer structure caused by airflow impact, thereby making the polyamide composition have good ablation resistance.

[0012] Furthermore, the D50 of the anhydrous zinc borate is obtained by laser particle size analyzer testing.

[0013] The D50 of the anhydrous zinc borate in the present invention is 3 to 10 μm, for example, but not limited to 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 and 10 μm, etc. can all achieve the present invention. Further, the D50 of the anhydrous zinc borate is 4 to 8 μm.

[0014] The average diameter of the glass fiber in the present invention is 9 to 15 μm, for example, but not limited to 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5 or 15 μm, etc. can all achieve the present invention. Further, the average diameter of the glass fiber is 10 to 13 μm.

[0015] Specifically, the average diameter of the glass fiber is tested by a microscope.

[0016] It should be noted that in the polyamide composition, the content of the polyamide resin is not less than 25 wt.%, for example, but not limited to, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, etc. In the polyamide composition, the content of the polyamide resin in the resin is not less than 80 wt.%.

[0017] Furthermore, the polyamide resin is semi-aromatic polyamide and / or aliphatic polyamide.

[0018] Specifically, the semi-aromatic polyamide is selected from one or more of PA6T / 66, PA6I, PA6T / 6I, PA6T / M5T, PA9T, PA9T / 66, PA10T, PA10T / 66, PA10T / 10I, PA10T / 1010, PA12T, and PA12I.

[0019] The aliphatic polyamide is selected from one or more of PA6, PA66, PA610, PA612, PA1010, PA1012, PA1212, PA11, and PA12.

[0020] Furthermore, the relative viscosity of the polyamide resin is 2.1 to 3.0, and specifically can be 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0, etc., which can realize the present invention.

[0021] Specifically, the relative viscosity of the polyamide resin is tested according to ISO 307-2019 standard.

[0022] In the present invention, the terminal amino group content in the polyamide resin is not less than 38 mmol / kg, and specifically can be not less than 40 mmol / kg, 45 mmol / kg, 50 mmol / kg, 55 mmol / kg, 60 mmol / kg, 65 mmol / kg, 70 mmol / kg, 75 mmol / kg, 80 mmol / kg, etc., all of which can achieve the present invention. Furthermore, the terminal amino group content in the polyamide resin is 40 to 85 mmol / kg.

[0023] Furthermore, the terminal amino group content in the polyamide resin is 45 to 55 mmol / kg.

[0024] Furthermore, the method for determining the content of terminal amino groups in the polyamide resin is the determination method HG / T4182-2012.

[0025] Furthermore, the polyamide composition comprises the following components calculated in parts by weight:

[0026]

[0027] Furthermore, the organophosphorus flame retardant is one or more of methyl ethyl aluminum hypophosphite, diethyl aluminum hypophosphite, diethyl zinc hypophosphite or diethyl titanium hypophosphite.

[0028] Furthermore, the lamellar filler is one or more of mica, kaolin, boehmite, montmorillonite or talc.

[0029] More preferably, the lamellar filler is mica and / or boehmite.

[0030] Furthermore, the mass ratio of the anhydrous zinc borate to the lamellar filler is (1-3):1.

[0031] Furthermore, the glass fibers include chopped strand A-, E-, C-, D-, S-, and R-glass fibers.

[0032] Furthermore, the polyamide composition further comprises 0.1 to 5 parts of an auxiliary agent.

[0033] Conventional additives in the art may be added to the polyamide composition of the present invention to impart or enhance corresponding properties, such as but not limited to one or more of antioxidants, lubricants, coupling agents, antistatic agents or colorants.

[0034] In a specific embodiment, the antioxidant is one or more of a hindered phenol antioxidant, a phosphite antioxidant or a thioester antioxidant.

[0035] The hindered phenol antioxidant is one or more of N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid n-octadecyl (Irganox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylate]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane (ADK AO-80).

[0036] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol phosphite (PEP-36) or 627A.

[0037] The thioester antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecylthiopropionate.

[0038] The lubricant is at least one of amides, stearates, esters or silicones.

[0039] The coupling agent is at least one of an epoxy silane coupling agent, an amino silane coupling agent, a titanate coupling agent or a vinyl silane coupling agent.

[0040] The electrostatic agent is one or more of polyethylene glycol esters or ethers, polyethylene oxide fatty ethyl ether, polyethylene oxide alkylphenyl ether, polyether ester amide, octyl styrene ether, polyether ester imide, fatty amine ethoxy ether or glycerol fatty acid ester.

[0041] The colorant is one or more of various pigments and dyes, such as carbon black, titanium dioxide, ultramarine, black, phthalocyanine blue, fluorescent orange, etc.

[0042] The present invention provides a method for preparing the polyamide composition, comprising the following steps:

[0043] The polyamide resin, glass fiber, organic phosphorus flame retardant, anhydrous zinc borate, flake filler and auxiliary agent are mixed uniformly, and then melt-blended and extruded to granulate to obtain a polyamide composition.

[0044] Furthermore, the extrusion granulation is carried out in a twin-screw extruder.

[0045] Furthermore, the temperature of zone one of the twin-screw extruder is 180-200°C, the temperature of zone two is 250-270°C, the temperature of zone three is 260-280°C, the temperature of zone four is 265-285°C, the temperature of zone five is 265-285°C, the temperature of zone six is ​​265-285°C, the temperature of zone seven is 260-280°C, the temperature of zone eight is 260-280°C, and the temperature of zone nine is 260-280°C, and the screw speed of the twin-screw extruder is 300-500 rpm.

[0046] The present invention also protects the use of the polyamide composition in preparing new energy electronic control components, such as electronic control boxes.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention provides a polyamide composition. The polyamide composition comprises a polyamide resin having a terminal amino group content of not less than 38 mmol / kg, and is added with a lamellar filler and anhydrous zinc borate. The polyamide composition can form a stable carbon layer structure during combustion, and can resist damage to the carbon layer structure caused by airflow impact, thereby improving the performance of the polyamide composition. The obtained polyamide composition can maintain its shape and be in a complete block after being ablated in a muffle furnace. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific embodiments, but the examples do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the examples of the present invention are conventionally purchased raw materials and reagents.

[0050] The raw materials used in the embodiments and comparative examples of the present invention are:

[0051] Polyamide resin:

[0052] Polyamide resin 1: PA66-EP158 NH, with an amino group content of 82 mmol / kg, purchased from Huafeng Group Co., Ltd.

[0053] Polyamide resin 2: PA66 EP 158, with a terminal amino group content of 47 mmol / kg, purchased from Huafeng Group Co., Ltd.

[0054] Polyamide resin 3: PA56 E1273, with an amino end content of 85 mmol / kg, purchased from Shanghai Kaisai;

[0055] Polyamide resin 4: PA66 EP 1107, with a terminal amino group content of 35 mmol / kg, purchased from Huafeng Group Co., Ltd.

[0056] Fiberglass:

[0057] Glass fiber 1: ECS10-03-568H, average diameter 10 μm, purchased from China Jushi Co., Ltd.

[0058] Glass fiber 2: ECS11-4.5-560A, average diameter 11 μm, purchased from China Jushi Co., Ltd.

[0059] Glass fiber 3: ECS13-03-508H, average diameter 13 μm, purchased from China Jushi Co., Ltd.

[0060] Glass fiber 4: ECS7-4.5-T435TM, average diameter 7 μm, purchased from Taishan Glass Fiber Co., Ltd.

[0061] Glass fiber 5: EDR17-2400-362H, average diameter 17 μm, purchased from China Jushi Co., Ltd.

[0062] Organophosphorus flame retardant: LFR-8003, purchased from Jiangsu Liside New Materials Co., Ltd.

[0063] Lamellar filler:

[0064] Lamellar filler 1: mica powder-P325 mother, purchased from Jiangmen Jingda Mica Materials Co., Ltd.;

[0065] Lamellar filler 2: boehmite, BG-613SO, purchased from Anhui Yishitong Materials Technology Co., Ltd.

[0066] Lamellar filler 3: montmorillonite, NB-802, purchased from Jiangxi Weipu Technology Co., Ltd.;

[0067] Non-lamellar filler: calcium carbonate, AC-05N, purchased from Guangdong Xianglong Technology;

[0068] Anhydrous zinc borate:

[0069] Anhydrous zinc borate 1: ZB-503, D50 of 4 μm, purchased from Anhui Yishitong Materials Technology Co., Ltd.;

[0070] Anhydrous zinc borate 2: FIBRAKE 500; D50 is 9 μm, purchased from Borax Europe Limited;

[0071] Anhydrous zinc borate 3: D50 is 3.5 μm, obtained by grinding and sieving anhydrous zinc borate 2;

[0072] Anhydrous zinc borate 4: D50 is 8 μm, obtained by grinding and sieving anhydrous zinc borate 2;

[0073] Anhydrous zinc borate 5: D50 is 2 μm, obtained by grinding and sieving anhydrous zinc borate 2;

[0074] Anhydrous zinc borate 6: NORD-min ZB 5W, D50 of 12 μm, purchased from NORDMANN Rassmann GmbH;

[0075] Hydrous zinc borate: HT-207, D50 7 μm, purchased from Taixing Fine Chemical Co., Ltd.

[0076] Antioxidant: Antioxidant 1098, commercially available; the same raw materials were used in the parallel experiments of Examples and Comparative Examples.

[0077] According to the formulations in Tables 1 to 3, a halogen-free flame retardant polyamide composition was prepared according to the following preparation method:

[0078] A polyamide resin, glass fiber, an organophosphorus flame retardant, anhydrous zinc borate and a lamellar filler are placed in a high-speed mixer and mixed for 1 minute, and then placed in a twin-screw extruder for melt blending and extrusion granulation to obtain a polyamide composition; the temperature of zone 1 of the twin-screw extruder is 190° C., the temperature of zone 2 is 260° C., the temperature of zone 3 is 270° C., the temperature of zone 4 is 275° C., the temperature of zone 5 is 275° C., the temperature of zone 6 is 275° C., the temperature of zone 7 is 270° C., the temperature of zone 8 is 270° C., and the temperature of zone 9 is 270° C.; and the screw speed of the twin-screw extruder is 400 rpm.

[0079] Table 1 Amount of each component in the polyamide composition in Examples 1 to 7 (Unit: parts by weight)

[0080]

[0081] Table 2 Amount of each component in the polyamide composition in Examples 8 to 14 (Unit: parts by weight)

[0082]

[0083]

[0084] Table 3 Amount of each component in the polyamide composition of Comparative Examples 1 to 8 (Unit: parts by weight)

[0085]

[0086] Performance Testing

[0087] 1. Test Method

[0088] The polyamide compositions prepared in the above examples and comparative examples were subjected to performance tests, and the specific test items and test methods are as follows:

[0089] (1) Ablation resistance test: The polyamide compositions prepared in the above examples and comparative examples were injection molded into standard bending specimens according to ISO 178, and then placed in a muffle furnace (3 samples were tested for each group). After calcination at 800° C. for 5 minutes, the appearance of the samples was observed, and the stress of the carbon layer was tested using a mechanical tester according to standard ISO 178-2019;

[0090] (2) Tensile strength performance test: The polyamide compositions prepared in the above examples and comparative examples were tested according to the standard ISO 527-2-2012.

[0091] 2. Test results

[0092] The performance test results of the polyamide compositions prepared in the examples and comparative examples are shown in Table 4.

[0093] Table 4 Performance test results of various embodiments and comparative examples

[0094]

[0095]

[0096] As can be seen from Table 3, the polyamide compositions prepared in various embodiments of the present invention have good ablation resistance, can maintain their shape and retain intact blocks after ablation in a muffle furnace, and have good mechanical properties. The tensile strength is not less than 90 MPa, and the stress of the carbon layer after ablation is not less than 20 N. In most embodiments, the tensile strength is not less than 120 MPa, and the stress of the carbon layer after ablation is not less than 30 N.

[0097] It can be seen from Comparative Example 1 that when the terminal amino group content in the selected polyamide resin is too low, the obtained polyamide composition collapses and becomes loose after being ablated in a muffle furnace, and its ablation resistance is significantly reduced.

[0098] It can be seen from Comparative Example 2 that when aqueous zinc borate is used, the ablation resistance of the obtained polyamide composition is significantly reduced even if a polyamide resin with a specific end amino group content and a lamellar filler are added.

[0099] It can be seen from Comparative Example 3 that when no lamellar filler is added, the ablation resistance of the obtained polyamide composition also decreases significantly.

[0100] It can be seen from Comparative Example 4 that if non-lamellar fillers are used, they cannot achieve a good compounding effect with anhydrous zinc borate, and the ablation resistance of the obtained polyamide composition is significantly reduced.

[0101] It can be seen from Comparative Examples 5 and 6 that when the D50 of the anhydrous zinc borate used is too small or too large, the ablation resistance of the obtained polyamide composition is significantly reduced.

[0102] It can be seen from Comparative Examples 7 and 8 that when the average diameter of the glass fiber used is outside the range of this application, the ablation resistance of the obtained polyamide composition decreases.

[0103] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A polyamide composition, characterized in that The composition includes the following components calculated in parts by weight: 28-80 parts of polyamide resin; 10-42 parts of glass fiber; 10-30 parts of organophosphorus flame retardant; 0.5-3.5 parts of anhydrous zinc borate; 0.5-5 parts of lamellar filler; The terminal amino content of the polyamide resin is not less than 45 mmol / kg; the D50 of the anhydrous zinc borate is 3 to 10 μm; the average diameter of the glass fiber is 9 to 15 μm; and the lamellar filler is one or more of mica, kaolin, boehmite, montmorillonite or talc.

2. The polyamide composition according to claim 1, characterized in that The polyamide resin has a terminal amino group content of 45 to 85 mmol / kg.

3. The polyamide composition according to claim 1, characterized in that The D50 of the anhydrous zinc borate is 4 to 8 μm.

4. The polyamide composition according to claim 1, characterized in that The organic phosphorus flame retardant is one or more of methyl ethyl aluminum hypophosphite, diethyl aluminum hypophosphite, diethyl zinc hypophosphite or diethyl titanium hypophosphite.

5. The polyamide composition according to claim 1, characterized in that The mass ratio of the anhydrous zinc borate to the lamellar filler is (1-3):

1.

6. The polyamide composition according to claim 1, characterized in that The polyamide composition further comprises 0.1 to 5 parts of an auxiliary agent; the auxiliary agent comprises one or more of an antioxidant, a lubricant, a coupling agent, an antistatic agent or a colorant.

7. A method for preparing the polyamide composition according to claim 6, characterized in that: The steps include: The polyamide resin, glass fiber, organic phosphorus flame retardant, anhydrous zinc borate, lamellar filler and auxiliary agent are mixed uniformly, and then melt-blended and extruded to granulate to obtain a polyamide composition.

8. Use of the polyamide composition according to any one of claims 1 to 6 in the preparation of new energy electronic control component materials.

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