Polyamide composition, preparation method therefor, and use thereof

Abstract

Disclosed in the present invention are a polyamide composition, a preparation method therefor and the use thereof. The polyamide composition uses a polyamide resin as a matrix resin; and adding a hollow glass microbead masterbatch, a red phosphorus flame retardant and a reinforcement fiber enables the prepared polyamide composition to have the properties of low density, high toughness, flame retardance and high modulus. The hollow glass microbead masterbatch contains a first toughening agent and a first coupling agent. Applying an aromatic polyamide resin in cooperation with the red phosphorus flame retardant can satisfy relatively high flame retardance in the case of a relatively small dosage of the flame retardant, thereby preventing the problem of a density increase. Therefore, the prepared polyamide composition has good flame retardance and low density, and also has good toughness.

Description

A polyamide composition and its preparation method and application 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 resins, with their excellent mechanical properties, wear resistance, and solvent resistance, are widely used in drones, automobiles, electronics, medical devices, and other fields. With the development of the industry, the development of lightweight products has become a major trend. Lightweighting helps reduce payload costs, increase effective weight, and extend service life. This is particularly true for drone applications, where miniaturization is possible.

[0003] Reducing the overall density of drones not only reduces the weight of the platform and improves accuracy, but also increases flight endurance. Components like the housing and propellers require high toughness and modulus to withstand collisions and drops. Furthermore, drones offer advantages such as strong real-time performance, flexibility, minimal environmental impact, and low cost. They hold broad potential for development and application in disaster emergency response, such as using drone systems for forest fire monitoring. This places even higher demands on the flame retardancy of the base material.

[0004] In order to meet the requirements of use in fields such as drones, hollow glass microspheres are currently added, which can effectively reduce the density, but will cause a significant decrease in the toughness of the material. For the current flame retardant polyamide, due to the high density of the flame retardant, it will make it difficult to reduce the density of the system and reduce the toughness of the material. Usually, the impact strength of flame retardant polyamide materials is not higher than 5kJ / m 2 , density not less than 1.1g / cm 3 If the amount of flame retardant is too low, it is difficult to meet the higher flame retardancy requirements, and it is difficult to balance the flame retardancy of polyamide materials with low density and high toughness. Therefore, there is a need in the art to develop a flame retardant low-density polyamide composition that also has good toughness. Summary of the Invention

[0005] The purpose of the present invention is to provide a polyamide composition in order to overcome the problems or defects in the prior art that the polyamide composition is difficult to balance the flame retardant effect and low density performance, and the addition of hollow microbeads will reduce the toughness.

[0006] Another object of the present invention is to provide a method for preparing the polyamide composition.

[0007] Another object of the present invention is to provide applications of the polyamide composition.

[0008] To achieve the above objectives, the present invention adopts the following technical solutions:

[0009] A polyamide composition comprising the following components calculated in parts by weight:

[0010] The polyamide resin is a mixture of an aliphatic polyamide resin and an aromatic polyamide resin, and the content of the aromatic polyamide resin is 25wt% to 75wt% of the polyamide resin; the hollow glass microbead masterbatch includes hollow glass microbeads, a first toughening agent and a first coupling agent, the content of the first coupling agent is not less than 0.3wt% of the hollow glass microbead masterbatch, and the content of the first toughening agent is not less than 3wt% of the hollow glass microbead masterbatch.

[0011] It should be noted that the first toughening agent and the second toughening agent may be the same or different; the first coupling agent and the second coupling agent may be the same or different.

[0012] The present invention provides a polyamide composition. The polyamide composition uses polyamide resin as a base resin. By adding hollow glass microbead masterbatch, red phosphorus flame retardant and reinforcing fiber, the prepared polyamide composition has low density, high toughness, flame retardancy and high modulus properties.

[0013] Specifically: The hollow glass microsphere masterbatch contains a first toughening agent and a first coupling agent, which can effectively improve the interface effect of the hollow glass microspheres directly added to the resin system, reduce the attenuation of toughness, and effectively reduce the pore breakage during the extrusion process; the selection of aromatic polyamide resin and red phosphorus flame retardant in synergy can achieve higher flame retardant performance with a lower amount of flame retardant added, thereby avoiding the problem of increased density; the addition of reinforcing fiber can effectively compensate for the modulus loss caused by the toughening agent and flame retardant. The coupling agent is added in batches to help better disperse at the interface and prevent agglomeration during the preparation of the masterbatch. The batch addition of the toughening agent can reduce the viscosity of the system during the preparation of the masterbatch, which causes pores in the hollow glass microspheres.

[0014] It should be noted that in the polyamide composition of the present invention, the content of the polyamide resin in the resin matrix is ​​not less than 50 wt %, for example, but not limited to, 52.5 wt %, 55 wt %, 57.5 wt %, 60 wt %, 62.5 wt %, 65 wt %, 67.5 wt %, 70 wt %, etc.

[0015] Specifically, the hollow glass microsphere masterbatch includes the following components calculated in parts by weight: 68 to 99 parts of hollow glass microspheres; 5 to 40 parts of a first toughening agent; and 0.5 to 2 parts of a first coupling agent.

[0016] Furthermore, the hollow glass microbead masterbatch further comprises 0 to 1 parts of an antioxidant.

[0017] The preparation method of hollow glass microbead masterbatch can adopt the conventional masterbatch preparation method in the prior art.

[0018] In a specific embodiment, the method for preparing the hollow glass microbead masterbatch comprises the following steps:

[0019] The first coupling agent is diluted with a solvent, mixed with other components, and kneaded to obtain hollow glass microbead masterbatch.

[0020] In a specific embodiment, the solvent is anhydrous ethanol.

[0021] Specifically, the mass volume ratio of the first coupling agent to the solvent is 1:10 to 1:20.

[0022] Specifically, the banburying is carried out by stirring at 90-130° C. for 5-10 minutes.

[0023] Furthermore, the polyamide composition comprises the following components calculated in parts by weight:

[0024] In the present invention, the content of the aromatic polyamide resin in the polyamide resin is 25wt% to 75wt%, for example, but not limited to 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt% or 75wt%, etc. can achieve the present invention. Furthermore, the content of the aromatic polyamide resin in the polyamide resin is 45wt% to 60wt%.

[0025] Furthermore, the aromatic polyamide resin may be any one or more of PA MXD6, PA MXD8, PA MXD10 or PA MXD12.

[0026] Specifically, the density of the aliphatic polyamide resin is 1.00 to 1.03 g / cm 3 The density of the aromatic polyamide resin is 1.05 to 1.08 g / cm 3 .

[0027] Specifically, the aliphatic polyamide resin is a long-chain polyamide resin. This refers to a polyamide resin in which the number of methylene groups between the amide groups in the repeating unit is ≥10. Examples include, but are not limited to, AB-type PA11 and PA12 prepared by ring-opening ω-amino acids or lactams, and PA612, PA610, PA1010, PA1012, and PA1212 prepared by polycondensation of dibasic acids and diamines.

[0028] Furthermore, the compressive strength of the hollow glass microspheres is 10,000 to 30,000 Psi.

[0029] Furthermore, the compressive strength of the hollow glass microspheres is tested by water isostatic pressure testing.

[0030] Specifically, the density of the hollow glass microspheres is 0.4 to 0.5 g / cm 3 .

[0031] Furthermore, the red phosphorus flame retardant is red phosphorus and / or red phosphorus masterbatch.

[0032] In a specific embodiment, the red phosphorus content in the red phosphorus flame retardant is 45 to 85 wt%.

[0033] Furthermore, the flame retardant synergist includes one or more of zinc borate, magnesium hydroxide, aluminum hydroxide or montmorillonite.

[0034] Furthermore, the first coupling agent is a carboxyl-containing polymer; and the second coupling agent is a carboxyl-containing polymer.

[0035] In a specific embodiment, the carboxyl group-containing polymer is an olefin acrylic acid copolymer and an ionic polymer thereof.

[0036] Specifically, the olefin acrylic acid copolymer and the ionic polymer thereof are one or more of ethylene-methacrylic acid-acrylate terpolymer resin, ionic polymer of ethylene-methacrylic acid-acrylate terpolymer resin, or ethylene-methacrylic acid.

[0037] Furthermore, the first toughening agent is a polyolefin containing a polar group; the second toughening agent is a polyolefin containing a polar group.

[0038] Furthermore, the polar group is one or more of maleic anhydride, epoxy group or ester group.

[0039] In a specific embodiment, the polyolefin containing polar groups is one or more of MAH-g-SEBS, MAH-g-POE, ethylene-methyl acrylate copolymer or GMA-g-POE.

[0040] Furthermore, the reinforcing fibers include glass fibers and / or carbon fibers.

[0041] Furthermore, the reinforcing fiber is carbon fiber.

[0042] Furthermore, the processing aid is an antioxidant and / or a lubricant.

[0043] In the present invention, commonly used antioxidants can be selected according to existing technologies, such as but not limited to one or more of hindered phenol antioxidants, phosphite antioxidants, diphenylamine antioxidants or thioether antioxidants.

[0044] Specifically, 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), triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate (Iragnox 259), β-(4-hydroxy-3,5-di-tert-butylphenyl) propionate n-octadecyl (Iragno 1076) or spiroethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] (ADK AO-80).

[0045] The phosphite antioxidant is one or more of 2,4-di-tert-butylphenol (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol phosphite (PEP-36) or 627A.

[0046] The diphenylamine antioxidant is 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine.

[0047] The thioether antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecylthiopropionate.

[0048] In the present invention, commonly used lubricants can be selected according to existing technologies, such as but not limited to one or more of stearic acid lubricants, polyethylene lubricants, amide lubricants, paraffin lubricants, ester lubricants or silicone lubricants.

[0049] Specifically, the stearic acid lubricant can be calcium stearate and / or zinc stearate.

[0050] The polyethylene lubricant may be polyethylene wax.

[0051] The amide lubricant can be one or more of oleamide lubricants, EBS amide lubricants or erucamide lubricants.

[0052] The ester lubricant may be one or more of aliphatic stearate, oleic acid-based aliphatic polyester, or meso-based aliphatic polyester.

[0053] The silicone lubricant may be polydimethylsiloxane.

[0054] The present invention also protects a method for preparing the above-mentioned polyamide composition, comprising the following steps:

[0055] S1. The polyamide resin, hollow glass microbead masterbatch, reinforcing fiber, a second toughening agent, a red phosphorus flame retardant, a flame retardant synergist, a second coupling agent and a processing aid are mixed to obtain a premix;

[0056] S2. The premix in step S1 is melt-blended and extruded into pellets to obtain a polyamide composition.

[0057] In a specific embodiment, the extrusion granulation in step S2 is carried out in a twin-screw extruder.

[0058] Specifically, the screw length-diameter ratio of the twin-screw extruder is 40-48:1, the barrel temperature of the twin-screw extruder is 220-250° C., and the screw speed of the twin-screw extruder is 150-400 rpm.

[0059] The present invention also protects the use of the above-mentioned polyamide composition in the preparation of drone casings and propeller materials.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The present invention provides a polyamide composition. A base resin containing an aromatic polyamide resin is selected and hollow glass microbead masterbatch is added. The interface between the hollow glass microbead and the resin system can be effectively improved. The aromatic polyamide resin and the red phosphorus flame retardant work together to achieve higher flame retardant performance with a lower amount of flame retardant added, thereby avoiding density increase. The density of the prepared polyamide composition is not higher than 1.1 g / m 3 The flame retardant grade meets the V-0 grade of 1.0mm, and the notched impact strength is not less than 7kJ / m 2 . DETAILED DESCRIPTION

[0062] 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.

[0063] The raw materials used in the embodiments and comparative examples of the present invention are:

[0064] Polyamide resin:

[0065] Polyamide resin 1: PA610 F150, purchased from Shandong Guangyin New Materials Co., Ltd.;

[0066] Polyamide resin 2: PA MXD10, purchased from Yinggu Co., Ltd.

[0067] Hollow glass microspheres: IM16K, density 0.46g / cm 3 , compressive strength 16000Psi, purchased from 3M Company of the United States;

[0068] Reinforcement Fiber:

[0069] Reinforcement fiber 1: glass fiber, S1HM435TM-10-3, length 3 mm, Taishan Glass Fiber Co., Ltd.

[0070] Reinforcement fiber 2: carbon fiber, Type-65, length 6mm, ZOLTEK;

[0071] Red phosphorus flame retardant:

[0072] Red phosphorus flame retardant 1: microcapsule coated red phosphorus masterbatch, FR9950T, red phosphorus content 50wt%, purchased from Tongcheng Xinde Co., Ltd.

[0073] Red phosphorus flame retardant 2: microcapsule coated red phosphorus, FRP-950X, red phosphorus content 80wt%, Guangzhou Yinsu Flame Retardant Material Co., Ltd.

[0074] Brominated flame retardant: brominated polystyrene, BPS 7010, Guangzhou Chengernuo Chemical Co., Ltd.

[0075] Flame retardant synergist: zinc borate, commercially available;

[0076] The first toughening agent: MAH-g-SEBS, FG1901 G, purchased from Kraton;

[0077] Second toughening agent: MAH-g-SEBS, FG1901 G, purchased from Kraton;

[0078] First coupling agent: ethylene-methacrylic acid-acrylate terpolymer resin, AN4228C, purchased from DuPont Chemical, USA;

[0079] Second coupling agent: ethylene-methacrylic acid-acrylate terpolymer resin, AN4228C, purchased from DuPont Chemical, USA;

[0080] Antioxidant: Inganox@1098; Lubricant: LOXIOL G32; both antioxidants and lubricants are commercially available, and the same antioxidants and lubricants are used in the parallel experiments of the examples and comparative examples.

[0081] According to the formula in Table 1, hollow glass microbead masterbatch was prepared according to the following preparation method:

[0082] First, the first coupling agent was diluted 10 times with anhydrous ethanol, and then added into an internal mixer with hollow glass microspheres, a second toughening agent, and an antioxidant in proportion, stirred at high speed to mix evenly, and internally kneaded at 130° C. to obtain hollow glass microsphere masterbatch.

[0083] Table 1 Amount of each component in hollow glass microbead masterbatch (unit: weight parts)

[0084] Examples 1 to 10 and Comparative Examples 1 to 5

[0085] According to the formulations in Tables 2 and 3, a polyamide composition was prepared according to the following preparation method:

[0086] S1. The polyamide resin, hollow glass microbead masterbatch, reinforcing fiber, a second toughening agent, a red phosphorus flame retardant, a flame retardant synergist, a second coupling agent and a processing aid are mixed to obtain a premix;

[0087] S2. The premix in step S1 is melt blended and extruded into pellets to obtain a polyamide composition; the screw aspect ratio of the twin-screw extruder is 40 to 48:1; the barrel temperature of the twin-screw extruder is 220 to 250°C, and the screw speed of the twin-screw extruder is 150 to 400 rpm.

[0088] Table 2 Amount of each component in the polyamide composition of Examples 1 to 7 (unit: parts by weight)

[0089] Table 3 Amount of each component in the polyamide composition of Examples 8 to 10 and Comparative Examples 1 to 5 (Unit: parts by weight)

[0090] Performance Testing

[0091] 1. Test Method

[0092] The lightweight polyamide compositions prepared in the above examples and comparative examples were subjected to performance tests:

[0093] (1) Density test: The polyamide compositions prepared in the above examples and comparative examples were tested according to ISO 1183-1-2019 standard, using an immersion method;

[0094] (2) Izod notched impact strength: The polyamide compositions prepared in the above examples and comparative examples were tested for notched impact strength according to ISO 180-2019; notch type: type A;

[0095] (3) Flame retardancy: The polyamide compositions prepared in the above examples and comparative examples were subjected to flame retardancy tests on specimens according to the relevant standards of UL 94 2013, with a sample thickness of 1.0 mm;

[0096] (4) Flexural modulus: The polyamide compositions prepared in the above examples and comparative examples were measured according to ISO 178-2010 standard at a bending speed of 2 mm / min.

[0097] 2. Test results

[0098] The performance test results of the polyamide compositions prepared in various examples and comparative examples are shown in Table 4.

[0099] Table 4 Performance test results of Examples 1 to 10 and Comparative Examples 1 to 5

[0100] It can be seen from Table 4 that the polyamide compositions prepared in various embodiments of the present invention have lower density and better flame retardant properties, as well as better toughness and rigidity. Specifically, the density is not higher than 1.1 g / m 3 The flame retardant grade meets the V-0 grade of 1.0mm, and the notched impact strength is not less than 7kJ / m 2 .

[0101] It can be seen from Comparative Example 1 that if the content of aromatic polyamide resin in the polyamide resin is too low, the flame retardant properties of the obtained polyamide composition are poor.

[0102] It can be seen from Comparative Example 2 that if other flame retardants are used, the density of other types of flame retardants is higher than that of red phosphorus flame retardant, and the flame retardant efficiency is not as good as that of red phosphorus flame retardant, and the density and flame retardancy of the obtained polyamide composition cannot meet the requirements.

[0103] It can be seen from Comparative Example 3 that if hollow glass microbead masterbatch is not used, even if the amount of coupling agent and toughening agent is increased in the polyamide composition, it is difficult to effectively improve the interface between the hollow glass microbeads and the polyamide resin, resulting in poor final toughness and a high density of the obtained polyamide composition.

[0104] It can be seen from Comparative Example 4 that if the content of aromatic polyamide resin in the polyamide resin is too high, the density of the obtained polyamide composition is relatively high and the toughness is relatively poor.

[0105] It can be seen from Comparative Example 5 that if the second toughening agent and the second coupling agent are not added to the polyamide composition but are added to the hollow glass microbead masterbatch, problems such as agglomeration during the preparation of the masterbatch, high system viscosity, and high porosity will occur, and the performance of the obtained polyamide composition will be reduced.

[0106] 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 comprises the following components calculated in parts by weight: The polyamide resin is a mixture of an aromatic polyamide resin and an aliphatic polyamide resin, and the content of the aromatic polyamide resin is 25wt% to 75wt% of the polyamide resin; the hollow glass microbead masterbatch includes hollow glass microbeads, a first toughening agent and a first coupling agent, the content of the first coupling agent is not less than 0.3wt% of the hollow glass microbead masterbatch, and the content of the first toughening agent is not less than 3wt% of the hollow glass microbead masterbatch.

2. The polyamide composition according to claim 1, characterized in that The hollow glass microbead masterbatch comprises the following components calculated in parts by weight: 68 to 99 parts of hollow glass microbeads; 5 to 40 parts of a first toughening agent; and 0.5 to 2 parts of a first coupling agent.

3. The polyamide composition according to claim 2, characterized in that The preparation method of the hollow glass microbead masterbatch comprises the following steps: The first coupling agent is diluted with a solvent, mixed with other components, and kneaded to obtain hollow glass microbead masterbatch.

4. The polyamide composition according to claim 1, characterized in that The content of aromatic polyamide resin in the polyamide resin is 45-60 wt%.

5. The polyamide composition according to claim 1, characterized in that The aromatic polyamide resin is any one or more of PA MXD6, PA MXD8, PA MXD10 or PA MXD12; the aliphatic polyamide resin is any one or more of PA612, PA610, PA1010, PA1012 or PA1212.

6. The polyamide composition according to claim 1, characterized in that The first coupling agent is a carboxyl-containing polymer; the second coupling agent is a carboxyl-containing polymer; preferably, the carboxyl-containing polymer is an olefin acrylic acid copolymer and an ionic polymer thereof; more preferably, the olefin acrylic acid copolymer and an ionic polymer thereof are one or more of ethylene-methacrylic acid-acrylate terpolymer resin, ionic polymer of ethylene-methacrylic acid-acrylate terpolymer resin or ethylene-methacrylic acid.

7. The polyamide composition according to claim 1, characterized in that The first toughening agent is a polyolefin containing a polar group; the second toughening agent is a polyolefin containing a polar group; preferably, the polyolefin containing a polar group is one or more of MAH-g-SEBS, MAH-g-POE, ethylene-methyl acrylate copolymer or GMA-g-POE.

8. The polyamide composition according to claim 1, characterized in that The reinforcing fibers include glass fibers and / or carbon fibers; preferably, the reinforcing fibers are carbon fibers.

9. A method for preparing the polyamide composition according to any one of claims 1 to 8, characterized in that: The steps include: S1. The polyamide resin, hollow glass microbead masterbatch, reinforcing fiber, a second toughening agent, a red phosphorus flame retardant, a flame retardant synergist, a second coupling agent and a processing aid are mixed to obtain a premix; S2. The premix in step S1 is melt-blended and extruded into pellets to obtain a polyamide composition.

10. Use of the polyamide composition according to any one of claims 1 to 8 in preparing drone casings and propeller materials.

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