Fiber-free flame-retardant polyamide composition as well as preparation method and application thereof

Abstract

The invention discloses a fiber-free flame-retardant polyamide composition as well as a preparation method and application thereof, and relates to the technical field of engineering plastics. The fiber-free flame-retardant polyamide composition comprises the following components in parts by weight: 55-81 parts of polyamide resin; 19-42 parts of a brominated flame retardant; 4-12 parts of zinc borate; 1-12 parts of antimony white; 0.1 to 0.6 part of zinc bromide; the viscosity of the polyamide resin is 2.4 to 2.7. The fiber-free flame-retardant polyamide composition disclosed by the invention can reach a 5VA flame-retardant level, and the appearance glossiness and the mirror surface effect are not influenced while the flame-retardant property is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastics of materials, and in particular to a fiberless flame-retardant polyamide composition, a preparation method thereof, and an application thereof. Background Art

[0002] Polyamide materials are a type of material widely used in engineering plastics. They have excellent heat resistance, solvent resistance, mechanical properties, and processing properties, and are widely used in fields such as electronics and electrical appliances, rail transit, power tools, household appliances, and sports equipment. With the development of the electronics and electrical appliances and new energy industries, higher and higher requirements are put forward for the flame-retardant properties of materials, such as the 5VA flame-retardant requirement. Conventional 5VA flame-retardant nylon materials all need to add glass fiber to the system to jointly act with the carbon layer during combustion to generate sufficient structural support so that it will not be burned through. However, after adding glass fiber, the surface effect of the parts, especially the gloss and mirror effect, will rapidly decline, making it difficult to be applied to parts with high appearance requirements. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a fiberless flame-retardant polyamide composition, a preparation method thereof, and an application thereof. The fiberless flame-retardant polyamide composition of the present invention can reach the 5VA flame-retardant level, and while improving the flame-retardant performance, it will not affect its appearance gloss and mirror effect.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides a fiberless flame-retardant polyamide composition, comprising the following components in parts by weight:

[0006] 55 - 81 parts of polyamide resin; 19 - 42 parts of brominated flame retardant; 4 - 12 parts of zinc borate; 1 - 12 parts of antimony white; 0.1 - 0.6 parts of zinc bromide; the viscosity of the polyamide resin is 2.4 - 2.7.

[0007] The present invention adds zinc borate to the bromine-antimony flame-retardant system, and cooperates with the complexing action generated by zinc bromide, and the two produce a synergistic effect, quickly forming a carbon layer with a certain strength during combustion to prevent the formation of holes due to the collapse of the melt during combustion, thereby improving the flame-retardant performance of the polyamide composition. If the viscosity of the polyamide resin is too large, the material is not easy to process; if the viscosity of the polyamide resin is too small, more small-molecule substances are more likely to be generated, which in turn affects the flame-retardant performance of the composition. Therefore, by controlling the viscosity of the polyamide resin within the above range, the present invention is beneficial to further improving the flame-retardant performance of the polyamide composition. And while improving the flame-retardant performance, it will not affect its appearance gloss and mirror effect.

[0008] Preferably, the viscosity of the polyamide resin is any one or a range value of two of 2.4, 2.5, 2.6, and 2.7.

[0009] The viscosity of the polyamide resin described in the present invention is measured at room temperature according to the test method of ISO307-2019.

[0010] Preferably, the polyamide resin includes at least one of PA6, PA66, and PA6T / 66.

[0011] Preferably, the brominated flame retardant includes at least one of brominated polystyrene, brominated epoxy resin, and decabromodiphenylethane.

[0012] More preferably, the brominated flame retardant includes brominated polystyrene and brominated epoxy resin, and the weight ratio of brominated polystyrene to brominated epoxy resin is greater than 2:1, specifically including but not limited to 3:1, 4:1, 5:1, and 6:1.

[0013] Preferably, the fiberless flame-retardant polyamide composition includes the following components in parts by weight:

[0014] 56-80 parts of polyamide resin; 20-40 parts of brominated flame retardant; 5-10 parts of zinc borate; 2-10 parts of antimony white; 0.1-0.5 parts of zinc bromide.

[0015] Preferably, the average particle size of the zinc borate is 5-15 microns, the average particle size of the zinc bromide is 10-50 microns, and the average particle size of the antimony white is 0.5-5 microns.

[0016] The particle size described in the present invention is tested according to the ISO 13320-2020 standard.

[0017] Preferably, the fiberless flame-retardant polyamide composition further includes 0.1-0.5 parts of antioxidant.

[0018] More preferably, the antioxidant includes a hindered phenol antioxidant or a hindered amine antioxidant.

[0019] The melt flow rate of the fiberless flame-retardant polyamide composition described in the present invention is 5-50 g / 10 min. The melt flow rate test is carried out according to the ISO-1-2022 standard.

[0020] In a second aspect, the present invention also discloses a preparation method of a fiberless flame-retardant polyamide composition, including the following steps:

[0021] Mix the components and then add them to a twin-screw extruder, and obtain the fiberless flame-retardant polyamide composition after granulation and cooling.

[0022] Preferably, the temperature of the twin-screw extruder is 190-275 °C, and the screw speed is 300-500 revolutions per minute.

[0023] More preferably, the extrusion temperature of the twin-screw extruder is: Zone 1: 190 °C, Zone 2: 260 °C, Zone 3: 270 °C, Zone 4: 275 °C, Zone 5: 275 °C, Zone 6: 275 °C, Zone 7: 270 °C, Zone 8: 270 °C, Zone 9: 270 °C.

[0024] Thirdly, the present invention also discloses the application of the fiberless flame-retardant polyamide composition in electronic and electrical appliances, and new energy.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) By adding zinc borate to the bromine-antimony flame-retardant system and cooperating with the complexing action generated by zinc bromide, the two produce a synergistic effect, and a carbon layer with a certain strength is quickly formed during combustion, preventing the formation of holes due to the collapse of the melt during combustion, thereby improving the flame-retardant performance of the polyamide composition.

[0027] (2) The fiberless flame-retardant polyamide composition of the present invention can reach the 5VA flame-retardant level, and while improving the flame-retardant performance, it will not affect its appearance gloss and mirror effect. Specific Embodiments

[0028] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the protection scope and implementation manner of the present invention are not limited thereto.

[0029] The materials, reagents, etc. used in the following examples are commercially available reagents and materials unless otherwise specified.

[0030] Examples 1-8

[0031] Examples of the fiberless flame-retardant polyamide composition of the present invention and its preparation method, and the composition components of the fiberless flame-retardant polyamide composition are shown in Table 1.

[0032] The preparation method of the fiberless flame-retardant polyamide composition includes the following steps:

[0033] Mix each component and add it to a twin-screw extruder, and obtain a fiberless flame-retardant polyamide composition after granulation and cooling.

[0034] Among them, the process parameters of the twin-screw extruder are:

[0035] Extrusion temperature: Zone 1: 190 °C, Zone 2: 260 °C, Zone 3: 270 °C, Zone 4: 275 °C, Zone 5: 275 °C, Zone 6: 275 °C, Zone 7: 270 °C, Zone 8: 270 °C, Zone 9: 270 °C; the screw speed is 300-500 revolutions per minute.

[0036] Comparative Examples 1-12

[0037] The differences between each comparative ratio and the examples only lie in the types and ratios of components, as shown in Table 2.

[0038] Among the components described in each example and comparative ratio:

[0039] The polyamide resin 1: PA66, with a viscosity of 2.1, manufactured by Invista, model PA66 U2501;

[0040] The polyamide resin 2: PA66, with a viscosity of 2.4, manufactured by Invista, model PA66 U3600NC01 SS;

[0041] The polyamide resin 3: PA66, with a viscosity of 2.7, manufactured by Invista, model PA66 U4800NC01 SS;

[0042] The polyamide resin 4: PA6, with a viscosity of 2.5, manufactured by Jiangsu Hongsheng, model BE3250.

[0043] The brominated flame retardant 1 is brominated polystyrene, Albemarle BPS 7010;

[0044] The brominated flame retardant 2 is brominated epoxy, CXB - 2000H, purchased from Woo Jin Copolymer Co., Ltd.;

[0045] The brominated flame retardant 3 includes brominated polystyrene and brominated epoxy, and the weight ratio of the two is 3:1;

[0046] The brominated flame retardant 4 includes brominated polystyrene and brominated epoxy, and the weight ratio of the two is 3:2.

[0047] The zinc borate, manufactured by Jinan Taixing Fine Chemical Co., Ltd., model HT - 207.

[0048] The antimony white, manufactured by Changde Chenzhou Antimony Products Co., Ltd., model S - 05N.

[0049] The glass fiber, manufactured by China National Fiberglass Co., Ltd., ECS10 - 03 - 568H.

[0050] The zinc bromide is commercially available.

[0051] The antioxidant is antioxidant 1098, BASF.

[0052] The zinc chloride is commercially available.

[0053] Unless otherwise specified, the component raw materials used in each example and comparative ratio of the present invention are all commercially available raw materials, and the component raw materials used in each parallel experiment are of the same kind.

[0054] Table 1

[0055]

[0056] Table 2

[0057]

[0058]

[0059] In order to verify the performance of the fiberless flame-retardant polyamide composition of the present invention, the fiberless flame-retardant polyamide compositions prepared in each example and comparative example were injection-molded into test specimens for testing the following properties.

[0060] Performance test methods:

[0061] 1. Combustion performance test: Tested in accordance with the UL 94 5VA test standard, and the thickness of the test specimen was 2.0 mm.

[0062] 2. Tensile strength: Tested in accordance with the ISO 527-2-2012 standard.

[0063] 3. Glossiness was tested in accordance with ASTM D523 at a geometric reflection angle of 60 degrees.

[0064] 4. Test of mirror effect: Visual inspection, divided into the following five levels according to the clarity of the mirror image:

[0065] Poor: Almost no mirror imaging effect;

[0066] Relatively poor: Barely having an imaging effect, but the effect is extremely poor;

[0067] Ordinary: Having a basic imaging effect and able to present a general outline;

[0068] Good: Having a good imaging effect and able to completely map the overall effect except for some details;

[0069] Clear: Able to completely map all details of the object.

[0070] The performance parameters obtained from the above tests are shown in Table 3 and Table 4.

[0071] Table 3

[0072]

[0073]

[0074] Table 4

[0075]

[0076] According to Examples 1-3, it can be seen that by controlling the viscosity of the polyamide resin within the range of 2.4-2.7, the polyamide composition can reach the 5VA flame retardant level, improving the flame retardant performance without affecting its appearance gloss and mirror effect.

[0077] Comparing Comparative Example 1 with Example 1, it can be obtained that the viscosity of the polyamide resin in Comparative Example 1 is too low, and the polyamide composition cannot pass the 5VA square plate test, indicating that the viscosity of the polyamide resin will have a certain impact on the flame retardant performance of the composition.

[0078] Comparing Comparative Examples 2-4 and 7 with Example 1 respectively, it can be obtained that in Comparative Example 2, antimony white is not added, in Comparative Example 3, zinc borate is not added, in Comparative Example 4, zinc bromide is not added, and in Comparative Example 7, zinc chloride is used to replace zinc bromide. The polyamide composition cannot pass the 5VA square plate test, indicating that only by adding zinc borate to the bromine-antimony flame retardant system and cooperating with the complexing effect generated by zinc bromide can the flame retardant performance of the polyamide composition be greatly improved.

[0079] Comparing Comparative Examples 5-6 with Example 1 respectively, it can be obtained that in Comparative Example 5, the content of zinc bromide is too low, and the polyamide composition cannot pass the 5VA square plate test; in Comparative Example 6, the content of zinc bromide is too high. Although the polyamide composition can pass the 5VA square plate test, the mirror effect of the polyamide composition is inferior to that of Example 1, indicating that by controlling the content of zinc bromide, the polyamide composition can not only reach the 5VA flame retardant level, but also be beneficial to improving the mirror effect of the polyamide composition.

[0080] Comparing Comparative Example 8 with Example 1, it can be obtained that in Comparative Example 8, glass fiber is added. Although the polyamide composition can pass the 5VA square plate test and the mechanical properties are improved, the mirror effect and gloss are significantly reduced.

[0081] Comparing Comparative Examples 9-10 with Example 1 respectively, it can be obtained that in Comparative Example 9, the content of the brominated flame retardant is too low, and the polyamide composition cannot pass the 5VA square plate test; in Comparative Example 10, the content of the brominated flame retardant is too high, and the mechanical properties and mirror effect of the polyamide composition will both decrease.

[0082] Comparing Comparative Examples 11-12 with Example 1 respectively, it can be obtained that in Comparative Example 11, the content of antimony white is too low, and the polyamide composition cannot pass the 5VA square plate test; in Comparative Example 12, the content of antimony white is too high, and the mechanical properties, mirror effect and clarity of the polyamide composition will all decrease.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A fiber-free flame-retardant polyamide composition, characterized in that: The composition comprises the following components in parts by weight: 55-81 parts of polyamide resin; 19-42 parts of brominated flame retardant; 4-12 parts of zinc borate; 1-12 parts of antimony white; 0.1-0.6 parts of zinc bromide; the viscosity of the polyamide resin is 2.4-2.

7.

2. The fiber-free flame-retardant polyamide composition according to claim 1, characterized in that: The polyamide resin includes at least one of PA6, PA66, and PA6T / 66.

3. The fiber-free flame-retardant polyamide composition according to claim 1, characterized in that: The brominated flame retardant includes at least one of brominated polystyrene, brominated epoxy and decabromodiphenylethane.

4. The fiber-free flame-retardant polyamide composition according to claim 3, characterized in that: The brominated flame retardant includes brominated polystyrene and brominated epoxy, and the weight ratio of the brominated polystyrene to the brominated epoxy is greater than 2:

1.

5. The fiber-free flame-retardant polyamide composition according to claim 1, characterized in that: The fiber-free flame-retardant polyamide composition comprises the following components in parts by weight: 56-80 parts of polyamide resin; 20-40 parts of brominated flame retardant; 5-10 parts of zinc borate; 2-10 parts of antimony white; 0.1-0.5 parts of zinc bromide.

6. The fiber-free flame-retardant polyamide composition according to claim 1, characterized in that: The fiber-free flame-retardant polyamide composition further comprises 0.1-0.5 parts of an antioxidant.

7. The fiber-free flame-retardant polyamide composition according to claim 6, characterized in that: The antioxidant includes a hindered phenol antioxidant or a hindered amine antioxidant.

8. The method for preparing the fiber-free flame-retardant polyamide composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: The components are mixed and added into a twin-screw extruder, and the fiber-free flame-retardant polyamide composition is obtained after granulation and cooling.

9. The method for preparing the fiber-free flame-retardant polyamide composition according to claim 8, characterized in that: The temperature of the twin-screw extruder is 190-275° C., and the screw speed is 300-500 rpm.

10. Application of the fiber-free flame-retardant polyamide composition according to any one of claims 1 to 7 in electronic and electrical applications and new energy.

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