Lightweight polyamide composition, preparation method therefor, and use thereof

Abstract

Disclosed in the present invention are a lightweight polyamide composition, a preparation method therefor, and the use thereof. The lightweight polyamide composition comprises the following components in parts by weight: 50-75 parts of polyamide resin, 15-25 parts of hollow glass microbeads, 10-20 parts of a toughening agent, 0.5-2 parts of a coupling agent, 0.1-1 part of a polymer having ultrahigh molecular weight and 0-1 part of an auxiliary agent, the coupling agent being a carboxyl-containing polymer, the toughening agent being a polyolefin containing a polar group, and the number-average molecular weight of the polymer having ultrahigh molecular weight being not less than 100W. By means of adding the carboxyl-containing coupling agent, the toughening agent containing the polar group and the polymer having ultrahigh molecular weight to the polyamide resin, the present invention enables the prepared polyamide composition to have better rigidity and toughness and low density.

Description

A lightweight 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 lightweight polyamide composition, a preparation method thereof, and applications thereof. Background Art

[0002] With the advancement of artificial intelligence, the Internet of Things, and 5G networks, the development of lightweight products has become a major trend. When promoting terminal products, the goal is to achieve lightweighting while maintaining material toughness and rigidity. Currently, lightweighting polymer products is primarily achieved through microfoaming or the addition of hollow, lightweight fillers. Microfoaming, which places higher demands on injection molding machines, is currently still in the laboratory stage. The addition of hollow, lightweight fillers is more mature, with hollow glass microspheres currently in industrial use.

[0003] Although the addition of hollow glass microspheres can reduce the density of the material, the weak interfacial bonding and poor compatibility between the hollow glass microspheres and the matrix resin easily form stress concentration points, thereby reducing the toughness of the composite material. While the addition of toughening agents can effectively improve toughness, it also reduces the rigidity of the composite material. For composite materials, it is difficult to balance toughness, rigidity, and density. Materials for swimming goggles, VR glasses, and drones require low density while also exhibiting good toughness and rigidity.

[0004] In the prior art, silane coupling agents and polyvinyl pyrrolidone are used to synergistically balance the toughness and rigidity of the material. Although this can improve the material's performance to a certain extent, the improvement is limited. Therefore, there is a need in the art to develop a lightweight polyamide composition that has both improved toughness and rigidity. Summary of the Invention

[0005] The purpose of the present invention is to provide a lightweight polyamide composition in order to overcome the defects in the prior art, wherein the lightweight polyamide composition has both good toughness and rigidity.

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

[0007] Another object of the present invention is to provide an application of the lightweight polyamide composition.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

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

[0010] The coupling agent is a carboxyl-containing polymer; the toughening agent is a polyolefin containing a polar group; and the number average molecular weight of the ultra-high molecular weight polymer is not less than 100W.

[0011] The present invention provides a lightweight polyamide composition. The lightweight polyamide composition has good rigidity and toughness by adding a carboxyl-containing polymer as a coupling agent, a polar group-containing polyolefin as a toughening agent, and an ultra-high molecular weight polymer. Specifically, hollow glass microspheres are usually processed from borosilicate raw materials, and their surface sodium ion content is relatively high, resulting in alkalinity. The use of a carboxyl-containing coupling agent can effectively improve the interface between the hollow glass microspheres and the matrix resin. The addition of a polar group-containing polyolefin can transfer internal stress from the matrix resin to the toughening agent, thereby improving the toughness of the material. At the same time, the introduction of the ultra-high molecular weight polymer will fiberize during the processing and shearing process to form a network structure, which can effectively increase the interaction between molecular chains, limit the relative slip between the molecular chains and the mobility of the molecular chains, thereby making the lightweight polyamide composition have good toughness and rigidity.

[0012] Furthermore, the carboxyl-containing polymer includes a carboxyl-containing olefin random copolymer or a carboxyl-containing olefin random copolymer ionomer.

[0013] Furthermore, the carboxyl group-containing polymer accounts for 2 to 15 wt% of the hollow glass microspheres, for example, but not limited to, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, and 15 wt%.

[0014] Furthermore, the carboxyl-containing polymer includes olefin acrylic acid copolymer and ionic polymer thereof.

[0015] Furthermore, the carboxyl group-containing polymer is one or more of ethylene-methacrylic acid-acrylate terpolymer resin, ionic polymer of ethylene-methacrylic acid-acrylate terpolymer resin, or ethylene-methacrylic acid.

[0016] Furthermore, the polar group in the toughening agent is one or more of maleic anhydride, epoxy group or ester group.

[0017] Furthermore, the polyolefin containing polar groups is one or more of MAH-g-SEBS, MAH-g-POE, ethylene-methyl acrylate copolymer or GMA-g-POE.

[0018] Furthermore, the mass ratio of the toughening agent to the hollow glass microspheres is 0.65 to 1.0.

[0019] In the present invention, the number average molecular weight of the ultra-high molecular weight polymer is not less than 100W, and specifically can be 100W, 150W, 200W, 250W, 300W, 350W, 400W, 450W, or 500W, etc., all of which can achieve the present invention. Furthermore, when the molecular weight of the ultra-high molecular weight polymer is 100-500W, the ultra-high molecular weight polymer is more likely to form a network structure within the system, which helps to improve the strength and impact properties of the polyamide composition.

[0020] Furthermore, the ultra-high molecular weight polymer is polytetrafluoroethylene.

[0021] Furthermore, the number average molecular weight of the ultra-high molecular weight polymer is determined by DSC differential thermal analysis, which is a method for measuring the thermal effect of polytetrafluoroethylene during melting and crystallization. Based on the heat of crystallization, the empirical formula Mn=2.1×10 10 ×ΔH -5.16 To calculate the number average molecular weight.

[0022] In the lightweight polyamide composition, the content of the polyamide resin 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.

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

[0024] Furthermore, the polyamide resin is semi-aromatic polyamide and / or aliphatic polyamide.

[0025] Specifically, the semi-aromatic polyamide is one or more of PA6T, PA9T, PA10T, PA11T, PA12T, PA13T, PA6T / 6I, PA6I / 6T, PA6T / 6I / 66, PA6I, PA6I / 6T, PA10T / 66, PA10T / 1010, and PA10T / 10I.

[0026] The aliphatic polyamide is one or more of PA66, PA610, PA612, PA1010, PA1012, PA1212, PA6, PA7, PA11, and PA12.

[0027] Furthermore, the polyamide resin is a long carbon chain polyamide resin. When a long carbon chain polyamide is used, the obtained lightweight polyamide composition has a better balance between rigidity and toughness.

[0028] It should be noted that the long-chain polyamide resin refers to a polyamide resin with 10 or more methylene groups between amide groups in the repeating unit. 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.

[0029] Furthermore, the compressive strength of the hollow glass microspheres is not less than 10000 Psi.

[0030] In a specific embodiment, the compressive strength of the hollow glass microspheres is 15,000 to 30,000 Psi.

[0031] Furthermore, the compressive strength of the hollow glass microspheres is tested by water isostatic pressure testing.

[0032] Furthermore, the auxiliary agent is an antioxidant and / or a lubricant.

[0033] 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, copper salt antioxidants or thioether antioxidants.

[0034] 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), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259 259), β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid n-octadecyl (Irganox 259 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).

[0035] 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.

[0036] The diphenylamine antioxidant is 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine.

[0037] The copper salt antioxidant is a mixture of 8:1:1 K / Cu / ZnBLEND or KI / CuI.

[0038] The thioether antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecylthiopropionate.

[0039] 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.

[0040] Specifically, the stearic acid lubricant can be calcium stearate and / or zinc stearate.

[0041] The polyethylene lubricant may be polyethylene wax.

[0042] The amide lubricant may be one or more of oleamide lubricants, EBS amide lubricants or erucamide lubricants.

[0043] The ester lubricant may be one or more of aliphatic stearate, oleic acid-based aliphatic polyester, or mesoic acid-based aliphatic polyester.

[0044] The silicone lubricant may be polydimethylsiloxane.

[0045] The present invention provides a method for preparing the above-mentioned lightweight polyamide composition, comprising the following steps:

[0046] S1. The polyamide resin, hollow glass microspheres, toughening agent, coupling agent, ultra-high molecular weight polymer and additives are mixed to obtain a premix;

[0047] S2. The premix in step S1 is melt-blended and extruded into pellets to obtain a lightweight polyamide composition.

[0048] Furthermore, the extrusion granulation in step S2 is carried out in a twin-screw extruder.

[0049] Furthermore, the screw length-to-diameter ratio of the twin-screw extruder is 40-48:1.

[0050] Furthermore, the screw barrel temperature of the twin-screw extruder is 220-250°C.

[0051] Furthermore, the screw speed of the twin-screw extruder is 150-400 rpm.

[0052] The present invention also protects the use of the above-mentioned lightweight polyamide composition in the preparation of drone materials, VR glasses or swimming goggles materials.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The present invention provides a lightweight polyamide composition. A coupling agent containing a carboxyl group is added to the polyamide composition to neutralize the alkalinity of hollow glass microspheres. A toughening agent containing a polar group is added to transfer internal stress from the polyamide resin to the toughening agent, thereby effectively improving the toughness of the material. Furthermore, the addition of an ultra-high molecular weight polymer can form a network structure by fiberization during processing and shearing, effectively increasing the interaction between molecular chains, limiting the relative slip between molecular chains and the mobility of the molecular chains, thereby making the lightweight polyamide composition have good toughness and rigidity at the same time, with a tensile strength of not less than 2100 MPa and a notched impact strength of not less than 7.5 kJ / m 2 . DETAILED DESCRIPTION

[0055] 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.

[0056] The raw materials used in the embodiments and comparative examples of the present invention are:

[0057] Polyamide resin:

[0058] Polyamide resin 1: PA610 F150, purchased from Shandong Guangyin New Materials Co., Ltd.;

[0059] Polyamide resin 2: PA66, PA66 U4800 NC01 SS, purchased from INVISTA;

[0060] Hollow glass beads:

[0061] Hollow glass microsphere 1: IM16K, compressive strength 16000Psi, purchased from 3M Company, USA;

[0062] Hollow glass microsphere 2: HL60-1800, compressive strength 18000 Psi, purchased from Zhengzhou Shenglait Hollow Microsphere New Materials Co., Ltd.

[0063] Hollow glass microsphere 3: IM30K, compressive strength 30000Psi, purchased from 3M Company, USA;

[0064] Toughening agent:

[0065] Toughener 1: MAH-g-SEBS, FG1901 G, purchased from Kraton;

[0066] Toughener 2: Ethylene-methyl acrylate copolymer, AC resin 1125, purchased from DuPont Chemical, USA;

[0067] Toughener 3: SEBS, SEBS 6150, purchased from Taiwan Rubber Corporation;

[0068] Coupling agent:

[0069] Coupling agent 1: ethylene-methacrylic acid-acrylate terpolymer resin, AN4228C, purchased from DuPont Chemical, USA;

[0070] Coupling agent 2: ionomer of ethylene-methacrylic acid-acrylate terpolymer resin (zinc ionomer), 9320, purchased from DuPont Chemical, USA;

[0071] Coupling agent 3: ethylene-methacrylic acid, nucrel599 / 699, purchased from Dow Chemical;

[0072] Coupling agent 4: 3-glycidyloxypropyltrimethoxysilane, JH-O187, purchased from Jingzhou Jianghan Fine Chemical Co., Ltd.

[0073] Ultra-high molecular weight polymers:

[0074] Ultra-high molecular weight polymer 1: polytetrafluoroethylene, X-010, number average molecular weight 1,000,000 g / mol, purchased from Shandong Dongyue Polymer Materials Co., Ltd.

[0075] Ultra-high molecular weight polymer 2: polytetrafluoroethylene, F201, number average molecular weight 3800000 g / mol, purchased from DAIKIN;

[0076] Low molecular weight polytetrafluoroethylene, F-5AEX-R, number average molecular weight 500,000 g / mol, was purchased from Solvay.

[0077] 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.

[0078] Examples 1 to 17 and Comparative Examples 1 to 3

[0079] According to the formulations in Tables 1 and 2, a lightweight polyamide composition was prepared according to the following preparation method:

[0080] S1. The polyamide resin, hollow glass microspheres, toughening agent, coupling agent, ultra-high molecular weight polymer and additives are mixed to obtain a premix;

[0081] S2. The premix in step S1 is put into a twin-screw extruder for melt blending and extrusion granulation to obtain a lightweight 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.

[0082] Table 1 Amount of each component in the lightweight polyamide composition of Examples 1 to 9 (parts by weight)

[0083] Table 2 Amount of each component in the lightweight polyamide composition of Examples 10 to 17 and Comparative Examples 1 to 3 (parts by weight)

[0084] Performance Testing

[0085] 1. Test Method

[0086] The lightweight polyamide compositions prepared in the above examples and comparative examples were subjected to performance tests:

[0087] (1) Density test: The polyamide compositions prepared in the above examples and comparative examples were tested according to ISO 1183-1-2019 standard;

[0088] (2) Tensile strength: The polyamide compositions prepared in the above examples and comparative examples were tested according to ISO 527-2:2012, 1A specimen;

[0089] (3) 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;

[0090] 2. Test results

[0091] The performance test results of the lightweight polyamide compositions prepared in the examples and comparative examples are shown in Table 3.

[0092] Table 3 Performance test results of Examples 1 to 17 and Comparative Examples 1 to 3

[0093] It can be seen from Table 3 that the density of the lightweight polyamide compositions prepared in various embodiments of the present invention is in the range of 0.8 to 0.95 g / cm 3 , and has good toughness and rigidity, specifically: the tensile strength is not less than 2100MPa, the notched impact strength is not less than 7.5kJ / m 2 .

[0094] It can be seen from Example 1 and Examples 10 to 11 that when the mass ratio of the toughening agent to the hollow glass microspheres is 0.65 to 1.0, the comprehensive performance of the prepared polyamide composition is improved. This may be because as the mass ratio of the toughening agent to the hollow glass microspheres increases, the processing performance of the system improves. However, when the toughening agent and the hollow glass microspheres are too large, the viscosity of the system increases, causing some glass microspheres to rupture and the performance to decline.

[0095] It can be seen from Comparative Example 1 that when a toughening agent without polar groups is used instead of the toughening agent in the present invention, the obtained lightweight polyamide composition is difficult to have both good toughness and rigidity. This is because the internal stress cannot be transferred from the polyamide resin to the toughening agent, resulting in poor toughness of the polyamide composition.

[0096] It can be seen from Comparative Example 2 that when a conventional coupling agent is used instead of the coupling agent of the present invention, the toughness of the obtained lightweight polyamide composition is poor, and the notched impact strength is only 4.3 kJ / m 2 .

[0097] It can be seen from Comparative Example 3 that when a polymer with a lower molecular weight is used, the toughness of the obtained lightweight polyamide composition is significantly poorer. This may be because the corresponding network structure cannot be formed in the system, and the slip between molecular chains and the mobility of the molecular chains cannot be effectively restricted, resulting in a decrease in the strength and impact properties of the polyamide composition.

[0098] 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 lightweight polyamide composition, characterized in that The composition comprises the following components calculated in parts by weight: The coupling agent is a polymer containing a carboxyl group; the toughening agent is a polyolefin containing a polar group; and the number average molecular weight of the ultra-high molecular weight polymer is not less than 100W.

2. The lightweight polyamide composition according to claim 1, characterized in that: The carboxyl-containing polymer includes olefin acrylic acid copolymer and ionic polymer thereof, preferably one or more of ethylene-methacrylic acid-acrylate terpolymer resin, ionic polymer of ethylene-methacrylic acid-acrylate terpolymer resin or ethylene-methacrylic acid.

3. The lightweight polyamide composition according to claim 1, characterized in that: The polar groups in the toughening agent are one or more of maleic anhydride, epoxy groups or ester groups.

4. The lightweight polyamide composition according to claim 1, characterized in that: The polyolefin containing polar groups is one or more of MAH-g-SEBS, MAH-g-POE, ethylene-methyl acrylate copolymer or GMA-g-POE.

5. The lightweight polyamide composition according to claim 1, characterized in that: The number average molecular weight of the ultra-high molecular weight polymer is 100-500W.

6. The lightweight polyamide composition according to claim 1, characterized in that: The ultra-high molecular weight polymer is polytetrafluoroethylene.

7. The lightweight polyamide composition according to claim 1, characterized in that: The polyamide resin is a long carbon chain polyamide resin.

8. The lightweight polyamide composition according to claim 1, characterized in that: The auxiliary agent is an antioxidant and / or a lubricant.

9. A method for preparing the lightweight polyamide composition according to any one of claims 1 to 8, characterized in that: The steps include: S1. The polyamide resin, hollow glass microspheres, toughening agent, coupling agent, ultra-high molecular weight polymer and additives are mixed to obtain a premix; S2. The premix in step S1 is melt-blended and extruded into pellets to obtain a lightweight polyamide composition.

10. Use of the lightweight polyamide composition according to any one of claims 1 to 8 in the preparation of drone materials, VR glasses or swimming goggles.

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