Polyamide composite material as well as preparation method and application thereof

Abstract

The invention discloses a polyamide composite material which comprises the following components in parts by weight: 40-55 parts of polyamide resin; 15 to 35 parts of a brominated polystyrene high polymer; 3 to 8 parts of brominated polystyrene oligomer; 3-8 parts of an antimony-containing flame retardant synergist; 30 to 60 parts of glass fiber; 5 to 15 parts of potassium titanate whisker; the weight-average molecular weight of the brominated polystyrene high polymer ranges from 180000 to 240000; the weight-average molecular weight of the brominated polystyrene oligomer ranges from 3000 to 6000. According to the invention, brominated polystyrene with high / low weight-average molecular weight is compounded and cooperates with potassium titanate whisker and glass fiber for synergistic enhancement, so that after modification, the brominated polystyrene can form a good interface effect with polyamide resin and a flame retardant, the compatibility is improved, and a stable interface structure is formed; the weather resistance reduction caused by the influence of the flame retardant under illumination and high temperature is avoided, the wear resistance is improved, and V-0 thin-wall flame retardance is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to a polyamide composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Nylon is widely used as an engineering material in various fields. With the continuous improvement of technology level, the variety of products is also increasing. However, with the development of modern high-tech, products with durability, wear resistance, flame retardancy, and complex structural design are gradually increasing, putting forward higher requirements for the comprehensive performance of materials. Traditional materials can no longer meet the market requirements. It is required to be wear-resistant while meeting the flame retardancy requirements. However, the defects of the flame retardant itself result in a decrease in the wear resistance and weather resistance of the material while meeting the flame retardancy, which is limited in industrial use. New solutions are needed to fill the current technological gap. Summary of the Invention

[0003] The purpose of the present invention is to provide a polyamide composite material with thin-wall flame retardancy, wear resistance, good light stability, and good thermal stability, a preparation method thereof, and an application thereof.

[0004] The present invention is realized through the following technical solutions: A polyamide composite material, by weight, comprises the following components: 40 - 55 parts of polyamide resin; 15 - 35 parts of high molecular weight brominated polystyrene; 3 - 8 parts of low molecular weight brominated polystyrene; 3 - 8 parts of antimony-containing flame retardant synergist; 30 - 60 parts of glass fiber; 5 - 15 parts of potassium titanate whiskers; The weight average molecular weight range of the high molecular weight brominated polystyrene is 180,000 - 250,000; The weight average molecular weight range of the low molecular weight brominated polystyrene is 3,000 - 6,000.

[0005] In the polyamide composite material of the present invention, the weight content of the polyamide resin can be 40 parts, 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 55 parts, etc., the weight content of the brominated polystyrene polymer can be 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, 25 parts, 27 parts, 29 parts, 31 parts, 33 parts, 35 parts, etc., the weight content of the brominated polystyrene oligomer can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc., the weight content of the antimony-containing flame retardant synergist can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc., the weight content of the glass fiber can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, etc., and the weight content of the potassium titanate whisker can be 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, etc.

[0006] Preferably, the brominated polystyrene polymer is 20 - 30 parts, the brominated polystyrene oligomer is 5 - 7 parts, the glass fiber is 40 - 50 parts, and the potassium titanate fiber is 8 - 12 parts.

[0007] The length range of the glass fiber that can achieve the purpose of the present invention is 2 - 7 mm, the diameter range is 9 - 15 μm, and the aspect ratio range of the potassium titanate whisker is 0.3 - 200.

[0008] The polyamide resin described above is selected from at least one of aliphatic polyamide resins and semi-aromatic polyamide resins.

[0009] Specifically, the aliphatic polyamide resin is selected from PA66, PA46, PA610, PA612, PA56, PA510, PA512, PA910, PA912, PA913, PA914, PA915, PA616, PA936, PA1010, PA1012, PA1013, PA1014, PA1210, PA1212, PA1213, PA1214, PA614, PA613, PA615, PA616, PA5, PA6, PA11, PA12, etc.

[0010] The semi-aromatic polyamide is selected from PA MXD6, PA10T, PA10T1010, PA10T66, PA6T, PA6T66, PA9T, etc.

[0011] The length range of the potassium titanate whisker can be 0.1 - 30 μm, and the diameter range can be 0.05 - 3 μm; preferably, the length range of the potassium titanate whisker is 0.2 - 20 μm, and the diameter range is 0.1 - 0.7 μm.

[0012] The antimony-containing flame retardant synergist described above is selected from at least one of antimony trioxide and antimony pentoxide.

[0013] The present invention does not limit the average particle size of the antimony-containing flame retardant synergist. Preferably, the average particle size range of the antimony-containing flame retardant synergist is 0.1 - 5 microns, which is obtained by testing with a laser particle size analyzer.

[0014] The test method for the weight-average molecular weight of brominated polystyrene is: gel permeation chromatography.

[0015] Whether to add 0 - 3 parts of additives can be selected according to actual needs. The additives are selected from at least one of antioxidants, lubricants, ultraviolet light absorbers, and silane coupling agents.

[0016] The preparation method of the polyamide composite material of the present invention includes the following steps: by weight, mix the components except glass fiber evenly, extrude and pelletize through a twin-screw extruder, and side-feed the glass fiber to obtain the polyamide composite material. The length-diameter ratio of the screw is 40 - 48:1, the barrel temperature is 230 - 260 °C, and the screw speed is 200 - 550 rpm.

[0017] The application of the polyamide composite material of the present invention is suitable for gears and machine tool accessories.

[0018] The present invention has the following beneficial effects: By selecting the compounding of high / low weight-average molecular weight brominated polystyrene, synergistically enhancing with potassium titanate whiskers and glass fiber, after modification, a good interfacial effect can be formed with polyamide resin and flame retardant, increasing compatibility, forming a stable interfacial structure, avoiding the reduction of weather resistance caused by the influence of the flame retardant under light and high temperature, and achieving V-0 thin-wall flame retardancy. Specific embodiments

[0019] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0020] The sources of the raw materials used in the present invention are as follows: PA66: PA66 EPR27, Shenma Group; PA6: PA6 HY-2800A, Ocean Chemical Fiber; PA10T: VICNYL 6100P, Zhuhai Wantong Special Engineering Plastics Co., Ltd.; PA1010: PA1010 G150, Shandong Guangyin New Materials Co., Ltd.; Brominated polystyrene A: BPS 7010, Shandong Tianyi, with a weight-average molecular weight of about 190,000; Brominated polystyrene B: XZ-6700, Shandong Brothers, weight average molecular weight about 240,000; Brominated polystyrene C: FR-803P, ICL, weight average molecular weight about 600,000.

[0021] Brominated polystyrene D: SR-3010, Shandong Xurui, weight average molecular weight about 4,000; Brominated polystyrene E: Phalmoon-103L, Taizhou Baili Chemical Co., Ltd., weight average molecular weight about 4,000; Decabromodiphenylethane: SAYTEX 8010, Albemarle Industries; Brominated epoxy: CXB-2000 WOOJIN COPOLYMER, weight average molecular weight is about 2000; Antimony trioxide: S-05N, Shanxing Antimony Industry; Glass fiber: ECS10-3.0-T435N, Taishan Group; Potassium titanate whisker A: length 10-20 μm, diameter 0.3-0.6 μm, TISMON, Otsuka Chemical Co., Ltd. Potassium titanate whisker B: length 0.2-8 μm, diameter 0.1-2 μm, mPTW, Shanghai Fengzhu Composite Materials Technology Co., Ltd.; Potassium titanate whisker C: length 0.6-1.0 μm, diameter <0.1 μm, Nptw, Nantong Aoxin Electronic Technology Co., Ltd.; Silane coupling agent: KH560, Nanjing Shuguang Chemical Plant; Embodiment and comparative example Preparation method of polyamide composite material: According to weight, each component except glass fiber is uniformly mixed, extruded and granulated by a twin-screw extruder, and glass fiber is fed sideways to obtain a polyamide composite material. The aspect ratio of the screw is 40-48:1, the barrel temperature is 230-260°C, and the screw speed is 200-550rpm.

[0022] Various test methods: (1) Light resistance: A 280T injection molding machine was used to mold a 100*100*2mm square plate at a rated speed of 50% and a pressure of 60 bar. After conditioning at 23°C and 50% humidity for 48 hours, the plate was exposed to sunlight for 3 months. The ΔE value of the square plate was tested before and after. The smaller the value, the better the light resistance.

[0023] (2) Flame retardancy: UL-94 is used to test the flame retardancy level of the material, which is divided into V-0, V-1 and V-2, and the specimen thickness is 0.8 mm.

[0024] (3)Abrasion resistance: Test was carried out on a color fastness abrasion tester. A 226N weight was applied, and 80-mesh coarse sandpaper was used as the abrading surface. The test was carried out at a frequency of 1 time / s, the cycle mileage was 100mm, and the cycle test was carried out 5000 times. The wear rate of the test sample was measured. The wear rate test method is as follows: Wear rate = (weight of the sample before test - weight of the sample after test) / weight of the sample before test * 100%.

[0025] Table 1: Component contents (parts by weight) and test results of flame-retardant polyamide materials in Examples 1-7 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PA66 48 48 48 48 PA6 40 PA10T 55 PA1010 48 Brominated polystyrene A 15 25 35 15 20 30 Brominated polystyrene B 33 Brominated polystyrene D 8 8 3 4 3 5 7 Antimony trioxide 3 5 8 4 5 5 5 Glass fiber 30 45 60 40 30 40 50 Potassium titanate whisker A 5 10 15 13 5 8 12 Silane coupling agent 0.3 0.7 1 0.5 0.7 0.7 0.7 Flame retardancy V-0 V-0 V-0 V-0 V-0 V-0 V-0 Wear rate, % 2.5 2.6 3.5 3.2 2.6 2.5 2.6 ΔE 3.6 3.4 4.3 3.9 3.6 3.3 3.4 It can be seen from Examples 2 / 5 - 8 that when the contents of each component are optimized, both the wear rate and ΔE are lower.

[0026] Table 2: Component contents (parts by weight) and test results of flame-retardant polyamide materials in Examples 8-11 Example 8 Example 9 Example 10 Example 11 PA66 48 48 48 48 Brominated polystyrene A 35 25 25 25 Brominated polystyrene D 8 8 8 Brominated polystyrene E 8 Antimony trioxide 5 5 5 5 Glass fiber 60 45 45 45 Potassium titanate whisker A 15 10 Potassium titanate whisker B 10 Potassium titanate whisker C 10 Silane coupling agent 0.7 0.7 0.7 0.7 Flame retardancy V-0 V-0 V-0 V-0 Wear rate, % 3.1 3.0 3.4 2.5 ΔE 3.8 3.7 4.2 3.5 It can be seen from Examples 2 / 9 / 10 that when the length and diameter of potassium titanate whiskers are optimized, both the wear rate and ΔE of the polyamide composite material are lower.

[0027] It can be seen from the above examples that the polyamide composite material of the present invention has V-0 flame retardancy, a wear rate lower than 4%, and ΔE less than 5.

[0028] Table 3: Component contents (parts by weight) and test results of flame-retardant polyamide materials in Comparative Examples Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 PA66 48 48 48 48 48 48 48 Brominated polystyrene A 33 22 25 25 Brominated polystyrene C 25 Brominated polystyrene D 8 11 8 8 Decabromodiphenylethane 33 Brominated epoxy 33 Antimony trioxide 5 5 5 5 5 5 5 Glass fiber 45 45 45 55 35 45 45 Potassium titanate whisker A 10 10 10 0 20 10 10 Silane coupling agent 0.7 0.7 0.7 0.7 0.7 0.7 0.7 Flame retardancy V-1 V-2 V-1 V-1 V-1 V-1 V-2 Wear rate, % 5.7 5.0 6.2 5.8 5.5 6.5 6.8 ΔE 7.5 7.8 8.2 9.3 6.8 7.8 8.6 It can be seen from Comparative Example 1 that when brominated polystyrene oligomer is not contained, the flame retardancy, abrasion resistance, and light resistance are significantly reduced.

[0029] It can be seen from Comparative Example 2 that when the weight average molecular weight of brominated polystyrene polymer is too high, the flame retardancy, abrasion resistance, and light resistance are also significantly reduced.

[0030] It can be seen from Comparative Example 3 that when the content of brominated polystyrene oligomer is too high, the flame retardancy, abrasion resistance, and light resistance are not high.

[0031] It can be seen from Comparative Examples 4 / 5 that when potassium titanate whiskers are not contained or the content of potassium titanate whiskers is too high, the flame retardancy, abrasion resistance, and light resistance are insufficient.

[0032] It can be seen from Comparative Examples 6 / 7 that when other types of brominated flame retardants are used to replace the brominated polystyrene of the present invention, the flame retardancy cannot reach V-0, and there is serious abrasion and poor light resistance.

Claims

1. A polyamide composite material, characterized in that: By weight, it includes the following components: 40-55 parts of polyamide resin; 15-35 parts of brominated polystyrene polymer; 3-8 parts of brominated polystyrene oligomer; Contains 3-8 parts of antimony flame retardant synergist; Glass fiber 30-60 parts; Potassium titanate whiskers 5-15 parts; The weight average molecular weight of the brominated polystyrene polymer is in the range of 180,000 to 250,000; The weight average molecular weight of the brominated polystyrene oligomer is in the range of 3000-6000.

2. The polyamide composite material according to claim 1, characterized in that: The brominated polystyrene polymer comprises 20-30 parts, the brominated polystyrene oligomer comprises 5-7 parts, the glass fiber comprises 40-50 parts, and the potassium titanate fiber comprises 8-12 parts.

3. The polyamide composite material according to claim 1, characterized in that: The polyamide resin is selected from at least one of aliphatic polyamide resin and semi-aromatic polyamide resin.

4. The polyamide composite material according to claim 1, characterized in that: The length of the potassium titanate whisker is in the range of 0.2-20 microns, and the diameter is in the range of 0.1-0.7 microns.

5. The polyamide composite material according to claim 1, characterized in that: The antimony-containing flame retardant synergist is selected from at least one of antimony trioxide and antimony pentoxide.

6. The polyamide composite material according to claim 1, characterized in that: The invention comprises 0-3 parts of auxiliary agents by weight, wherein the auxiliary agents are selected from at least one of antioxidants, lubricants, anti-ultraviolet agents and silane coupling agents.

7. The method for preparing the polyamide composite material according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: uniformly mixing the components except the glass fiber according to weight, extruding and granulating through a twin-screw extruder, and feeding the glass fiber sideways to obtain a polyamide composite material.

8. Use of the polyamide composite material according to any one of claims 1 to 6, characterized in that: Suitable for gears and machine tool accessories.