Anti-aging polyamide composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to an anti-aging polyamide composition as well as a preparation method and application thereof. The UVA ultraviolet light absorber and the UVB ultraviolet light absorber are added into the polyamide base material at the same time, full-wave-band protection on UVA ultraviolet light and UVB ultraviolet light can be achieved, and the weather resistance and the yellowing resistance of the material are remarkably improved; meanwhile, the hindered amine light stabilizer is matched for synergistic effect, so that the light degradation process is further delayed. By adding the phosphite anti-aging agent, the oxidation resistance is enhanced, and the performance can be kept stable in long-term use. According to the invention, the benzotriazole UVA ultraviolet absorbent and the amide UVB ultraviolet absorbent are selected for compounding, so that a polyamide base material can be adapted. Meanwhile, the total dosage of the two raw materials is limited, so that the compatibility of the two raw materials and polyamide is ensured, and the defects of agglomeration or precipitation and the like in the processing process are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a kind of anti-aging polyamide composition and its preparation method and application. BACKGROUND

[0002] The ultraviolet spectrum covers the wavelength 100-400nm section, divided into UVA (320-400nm), UVB (280-320nm), UVC (200-275nm) and UVD (100-200nm) four sections. The penetration ability of the four sections of ultraviolet gradually weakens, and the aging ability to the material gradually strengthens. Among them, UVC and UVD wavelength is shorter, and the penetration ability is weak, which will not cause material aging in the usual use environment; while UVA and UVB wavelength is longer, and the penetration ability is strong, which is the main section of ultraviolet that leads to material aging. Therefore, in order to prevent material aging, it is necessary to add effective light stabilizer to the material to absorb or shield UVA and UVB radiation.

[0003] In the prior art, CN111621147A discloses a kind of polyamide composition and its preparation method and application, which contains at least one or both of hindered amine light stabilizer and phosphite salt anti-aging agent, which can reduce color change under the double action of heating and moisture absorption and ultraviolet light. However, the ultraviolet absorber used in the invention does not cover the whole ultraviolet spectrum absorption section, and only focuses on covering the UVA section, which leads to insufficient protection against ultraviolet aging and limits its application in scenarios with high requirements for aging resistance. SUMMARY

[0004] The present application aims to provide a kind of anti-aging polyamide composition and its preparation method and application, to solve the technical problems that the polyamide composition in the prior art cannot effectively cover UVA and UVB double-band ultraviolet radiation, leading to insufficient aging resistance.

[0005] To solve the above technical problems, the present application adopts the following technical scheme: An anti-aging polyamide composition, characterized in that it comprises the following components by weight: Polyamide 0-99 parts by weight, chopped glass fiber 0-60 parts by weight, antioxidant 0.01-1 parts by weight, ultraviolet light absorber 0.1-6 parts by weight, hindered amine light stabilizer 0.1-3 parts by weight, phosphite salt anti-aging agent 0.1-3 parts by weight, toner 0.1-10 parts by weight; The ultraviolet light absorber is composed of UVA ultraviolet light absorber and UVB ultraviolet light absorber, and the sum of the amounts of the UVA ultraviolet light absorber and the UVB ultraviolet light absorber is 0.1-6 parts by weight; Preferably, the UVA ultraviolet light absorber includes 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol, which absorbs ultraviolet light at 300-400 nm and has an absorption peak at 343 nm. The UVB ultraviolet light absorber includes N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide, which absorbs ultraviolet light in the 280-320 nm range and has an absorption peak of 298 nm.

[0006] Preferably, the hindered amine light stabilizer comprises one or a mixture of two or more of the following: poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine, and pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid). The phosphonite / salt anti-aging agents include one or a mixture of two or more of the following: trialkyl phosphite, tri(alkylaryl) phosphite, dialkylaryl phosphite, spirocyclic phosphonite, tris(2,4-di-tert-butylphenyl)phosphonite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphonite, antioxidant P-EPQ, and sodium phenylphosphonite.

[0007] Preferably, the polyamide comprises one or a mixture of two or more of PA46, PA56, PA66, PA6, PA612, PA610, PA1010, PA6I / 6T, PA6T / 6I, PA6T / 66, PA5T / 56, PA5T / 6T, PA10T, PA10T / 66, PA9T, PA12, PAMACM12, PAPACM12, PAMACMI / MACMT / MACM12; When measured with m-cresol as a solvent, the Ubbelohde relative viscosity of the polyamide is 1.4-2.0 or 1.4-1.8.

[0008] Preferably, the length of the chopped glass fiber is 3-4.5 mm; the diameter of the chopped glass fiber is 8-15 μm; the cross-section of the chopped glass fiber is circular or elliptical; and the aspect ratio of the chopped glass fiber is 1:3-1:4.

[0009] Preferably, the antioxidant includes hindered phenolic antioxidants and phosphonite heat stabilizers; The amount of the hindered phenolic antioxidant is 0.1-0.5 parts by weight, and the amount of the phosphonite heat stabilizer is 0.1-0.5 parts by weight.

[0010] Preferably, the pigment powder includes one or a mixture of two or more of the following: titanium dioxide, ultrafine zinc sulfide powder, carbon black powder, ultramarine pigment blue 29, ultramarine pigment violet 15, pigment brown 24, pigment orange 75, pigment orange 78, pigment red 265, organic pigment yellow 215, organic pigment blue 15:1, organic pigment blue 15:3, organic solvent red 52, organic solvent red 179, and organic solvent yellow 98, wherein the particle size of the pigment powder is not less than 10,000 mesh.

[0011] The preparation method of the present invention is characterized by comprising the following steps: mixing polyamide, antioxidant, ultraviolet light absorber, hindered amine light stabilizer, phosphonite / salt anti-aging agent, and colorant evenly to form a mixture, and then adding the mixture into an extruder; During the extrusion process of the mixture, chopped glass fibers are added to the extruder by side feeding and simultaneously extruded at high temperature. After cooling, traction and pelletizing, a polyamide composition is obtained. The extrusion temperature of the extruder is 260-330℃.

[0012] Preferably, during raw material mixing, one or more components are pre-prepared into masterbatches and added to the extruder in the form of masterbatches.

[0013] The polyamide composition disclosed in this invention can be used to prepare appearance parts such as AR and VR eyeglass frames and smart glasses, and can also be used to prepare color identification parts such as safety locks in production safety management.

[0014] The advantages of this invention are: 1. This invention simultaneously incorporates UVA and UVB ultraviolet light absorbers into a polyamide substrate, achieving full-band protection against both UVA and UVB light and significantly improving the material's weather resistance and anti-yellowing properties. Furthermore, the synergistic effect of hindered amine light stabilizers further delays the photodegradation process. By adding phosphonites / salt anti-aging agents, this invention enhances antioxidant capacity, ensuring stable performance over long-term use. 2. This invention uses a benzotriazole-based UVA absorber and an amide-based UVB absorber in combination, which is compatible with polyamide substrates. Furthermore, controlling the total amount of both absorbers to 0.1-6 parts by weight ensures the compatibility of the two raw materials with the polyamide, preventing defects such as agglomeration or precipitation during processing. 3. This invention uses a combination of poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester and N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine as a hindered amine light stabilizer. The former can quickly capture free radicals to achieve short-term protection, while the latter has a long-term protective effect. The two work together to achieve stable protection throughout the aging process, avoiding the protection gap caused by the time-limited effect of a single light stabilizer. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown herein can be arranged and designed in various different configurations.

[0016] The preparation method of the present invention includes the following steps: Polyamide, antioxidant, UV absorber, hindered amine light stabilizer, phosphonite / salt anti-aging agent, and colorant are mixed and stirred evenly in a certain proportion to form a mixture. The mixture is then added into a twin-screw extruder. The twin-screw extruder has 10 temperature zones: the first and second zones are 260°C, and the other zones are 285°C; the main extruder speed is 300 rpm. During extrusion, chopped glass fibers are fed into the extruder via side feeding and extruded simultaneously at high temperature. After cooling, traction, and pelletizing, a polyamide composition is obtained.

[0017] The resulting polyamide composition was then dried in a dryer at 80°C for 4 hours, followed by injection molding. In another embodiment, when mixing raw materials, one or more components can be pre-prepared into masterbatches and added to the extruder in the form of masterbatches.

[0018] The following examples were all prepared using the above-described preparation method.

[0019] The polyamide can be selected from one or a mixture of two or more of PA46, PA56, PA66, PA6, PA612, PA610, PA1010, PA6I / 6T, PA6T / 6I, PA6T / 66, PA5T / 56, PA5T / 6T, PA10T, PA10T / 66, PA9T, PA12, PAMACM12, PAPACM12, PAMACMI / MACMT / MACM12; When measured with m-cresol as a solvent, the Ubbelohde relative viscosity of the polyamide is 1.4-2.0 or 1.4-1.8.

[0020] The length of the chopped glass fiber is 3-4.5 mm; the diameter of the chopped glass fiber is 8-15 μm; the cross-section of the chopped glass fiber is circular or elliptical; and the aspect ratio of the chopped glass fiber is 1:3-1:4.

[0021] The pigment powder includes one or a mixture of two or more of the following: titanium dioxide, ultrafine zinc sulfide powder, carbon black powder, ultramarine pigment blue 29, ultramarine pigment violet 15, pigment brown 24, pigment orange 75, pigment orange 78, pigment red 265, organic pigment yellow 215, organic pigment blue 15:1, organic pigment blue 15:3, organic solvent red 52, organic solvent red 179, and organic solvent yellow 98, wherein the particle size of the pigment powder is not less than 10,000 mesh.

[0022] Phosphite / salt antioxidants include one or a mixture of two or more of the following: trialkyl phosphite, tri(alkylaryl) phosphite, dialkylaryl phosphite, spirocyclic phosphite, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, antioxidant P-EPQ, and sodium phenylphosphite. Example 1

[0023] The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber comprises: 0.3 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 0.3 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0024] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0025] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process. Example 2

[0026] The white fiber-reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 62.77 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts of hindered phenolic antioxidant 1098 and 0.15 parts of phosphonite antioxidant 168; The ultraviolet light absorber comprises: 0.3 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 0.3 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0027] Phosphite / salt anti-aging agents, including: 0.3 parts of sodium phenylphosphite; The pigments include: 5 parts zinc sulfide, 0.01 parts ultramarine pigment blue 29, and 0.02 parts ultramarine pigment violet 15.

[0028] In addition, 0.3 parts of organosilicon flow modifier EMI-150C were added in this embodiment to improve the processing flowability of the material.

[0029] Comparative Example 1 The natural fiber-reinforced polyamide material of this comparative example is composed of the following components in parts by weight: Polyamide, including: 69.2 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts of hindered phenolic antioxidant 1098 and 0.15 parts of phosphonite antioxidant 168; 0.3 parts of organosilicon flow modifier EMI-150C; This comparative example does not contain any UV absorbers, hindered amine light stabilizers, or phosphonates / salts for anti-aging, and no colorants have been added, so the materials are naturally colored.

[0030] Comparative Example 2 The white fiber-reinforced polyamide material in this comparative example is composed of the following components in parts by weight: Polyamide, including: 64.17 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts of hindered phenolic antioxidant 1098 and 0.15 parts of phosphonite antioxidant 168; 0.3 parts of organosilicon flow modifier EMI-150C; The pigments include: 5 parts zinc sulfide, 0.01 parts ultramarine pigment blue 29, and 0.02 parts ultramarine pigment violet 15. This comparative example does not contain UV absorbers, hindered amine light stabilizers, or phosphonates / salts for anti-aging, but it does contain pigments, resulting in a white material.

[0031] Comparative Example 3 The natural fiber-reinforced polyamide material of this comparative example is composed of the following components in parts by weight: Polyamide, including: 68.1 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber includes: 0.3 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0032] Phosphite / salt anti-aging agents, including: 0.3 parts of sodium phenylphosphite; 0.3 parts of organosilicon flow modifier EMI-150C.

[0033] This comparative example does not contain any colorant, and the material is its natural color; it only contains the UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol, and does not contain any UVB ultraviolet light absorber.

[0034] Comparative Example 4 The white fiber-reinforced polyamide material in this comparative example is composed of the following components in parts by weight: Polyamide, including: 64.17 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts of hindered phenolic antioxidant 1098 and 0.15 parts of phosphonite antioxidant 168; The ultraviolet light absorber includes: 0.3 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0035] 0.3 parts of organosilicon flow modifier EMI-150C; The pigments include: 5 parts zinc sulfide, 0.01 parts ultramarine pigment blue 29, and 0.02 parts ultramarine pigment violet 15.

[0036] This comparative example contains colored powder, resulting in an overall white material. This comparative example only contains the UVA absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol; no UVB absorber was added.

[0037] Comparative Example 5 The natural fiber-reinforced polyamide material of this comparative example is composed of the following components in parts by weight: Polyamide, including: 68.1 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber includes: 0.3 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0038] Phosphite / salt anti-aging agents, including: 0.3 parts of sodium phenylphosphite; 0.3 parts of organosilicon flow modifier EMI-150C.

[0039] This comparative example does not contain any colorant, and the material is its natural color; it only contains the UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-ethylenediamide, and does not contain any UVA ultraviolet light absorber.

[0040] Comparative Example 6 The white fiber-reinforced polyamide material in this comparative example is composed of the following components in parts by weight: Polyamide, including: 64.17 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts of hindered phenolic antioxidant 1098 and 0.15 parts of phosphonite antioxidant 168; The ultraviolet light absorber includes: 0.3 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0041] 0.3 parts of organosilicon flow modifier EMI-150C; The pigments include: 5 parts zinc sulfide, 0.01 parts ultramarine pigment blue 29, and 0.02 parts ultramarine pigment violet 15.

[0042] This comparative example contains colored powder, resulting in an overall white material. This comparative example contains only the UVB absorber N-(2-ethoxyphenyl)-N'-(4-ethylphenyl)-ethylenediamide; no UVA absorber was added.

[0043] Aging performance test The performance of the materials obtained in the comparative examples and embodiments was tested and evaluated using the following methods. 1) Color difference measurement: D65 light source, 10-degree angle, D8 structural colorimeter; 2) Color difference measurement environment: 23℃, 50% relative humidity; 3) Moisture absorption, heating, and ultraviolet light aging conditions, including two steps: light irradiation and heating for moisture absorption.

[0044] Irradiation: Simultaneous irradiation with UVA-340 and UVB-297 lamps, irradiation intensity 0.71W / m² 2 / nm@340 / 297nm, blackboard temperature 65℃, humidity 35%, detection time 12h.

[0045] Heating and moisture absorption: temperature 50℃, humidity 95%, detection time 12h.

[0046] One light exposure and one heating-moisture absorption constitute one complete test cycle. The entire aging process includes 9 cycles totaling 216 hours. After the test, the samples were removed and allowed to recover for 2 hours at 23℃ and 50% relative humidity. Color difference was then measured, and the results are as follows: Table 1. UV resistance test results of the examples and comparative examples. Test item Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Color Natural color White Natural color White Natural color White Natural color White Color difference (DE) 0.73 2.85 9.60 11.2 1.7 4.37 3.48 6.61

[0047] Based on the test results in the table above, it can be seen that the UV-resistant polyamide of the present invention, after adding UVB ultraviolet absorbers in Examples 1 and 2, exhibits excellent UV aging resistance performance, which is significantly better than the materials in Comparative Examples 3-6 that only added a single ultraviolet absorber. This indicates that the simultaneous addition of UVB and UVA ultraviolet absorbers has a better synergistic protective effect than the addition of a single UVA / UVB ultraviolet absorber or no ultraviolet absorber. It can effectively slow down the performance degradation of the material under long-term light and humid heat environment, significantly reduce color difference changes, and thus improve the weather resistance and appearance stability of the polyamide material. Example 3

[0048] The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber comprises: 0.05 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 0.05 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0049] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0050] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process. Example 4

[0051] The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber comprises: 3 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 3 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0052] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0053] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process.

[0054] Comparative Example 7 The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber comprises: 4 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 4 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0055] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0056] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process.

[0057] Comparative Example 8 The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber comprises: 5 parts of UVA ultraviolet light absorber 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol and 5 parts of UVB ultraviolet light absorber N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide; The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0058] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0059] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process.

[0060] Comparative Example 9 The unbleached glass fiber reinforced polyamide material of this embodiment is composed of the following components in parts by weight: Polyamide, including: 67.8 parts of polyamide PA66; 30 parts of chopped glass fiber; Antioxidants, including: 0.35 parts hindered phenolic antioxidant 1098 and 0.15 parts phosphonite antioxidant 168; The ultraviolet light absorber includes: 0.3 parts of UVA ultraviolet light absorber and 0.3 parts of UVB ultraviolet light absorber; wherein the UVA ultraviolet light absorber is UV-1164, which is a triazine ultraviolet light absorber, and the UVB ultraviolet light absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide. The hindered amine light stabilizer comprises: 0.3 parts of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine and 0.2 parts of polysuccinate (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol).

[0061] Phosphite / salt anti-aging agent, comprising: 0.3 parts of sodium phenylphosphite.

[0062] No color powder is added in this embodiment, and the material is its natural color. In addition, 0.3 parts of silicone-based flow modifier EMI-150C are added in this embodiment to improve the processing fluidity of the material, reduce the melt viscosity, thereby improving the surface finish of the product and reducing mold fouling during the injection molding process.

[0063] The polyamide materials prepared in Examples 1, 3, 4, and Comparative Examples 7-8 were subjected to aging performance tests and appearance defect tests. The aging performance test method was the same as described above. The appearance defect test method involved injection molding the polyamide material into standard test strips of 170mm × 20mm × 4mm, and counting the number of surface defects on the standard test strips. Defects included visible abnormalities caused by incompatibility phenomena such as precipitation, pitting, delamination, and whitening. To reduce error, three standard test strips were used for each group. The test results are as follows: Table 2 Comparison of aging performance of Examples 1, 3, 4 and Comparative Examples 7-9 Test item Example 1 Example 3 Example 4 Comparative Example 7 Comparative Example 8 Comparative Example 9 Color Natural color Natural color Natural color Natural color Natural color Natural color Color difference (DE) 0.73 1.80 0.53 0.51 0.48 1.50

[0064] Comparing Example 1 and Comparative Example 9, it can be seen that the combined use of triazine UVA and UVB absorbers can also improve the UV aging resistance of materials to a certain extent. However, compared with benzotriazole UVA absorbers, the synergistic effect of UV aging resistance is weaker.

[0065] Compared with Comparative Examples 7-8, Examples 1, 3, and 4 all showed smaller color difference changes, indicating that the simultaneous addition of UVA and UVB ultraviolet light absorbers can effectively synergistically inhibit the photo-oxidation reaction caused by ultraviolet radiation during the aging process of polyamide materials. The color difference of 1.80 in Example 3 is higher than that in Examples 1 and 4 because the amount of UVA and UVB ultraviolet light absorbers added is smaller. However, when the total amount of UVA and UVB ultraviolet light absorbers added reaches 0.6 parts, the color difference change tends to stabilize.

[0066] Table 3. Results of appearance defect tests for Examples 1, 3, 4 and Comparative Examples 7-9 Sample No. Number of defects of sample 1 Number of defects of sample 2 Number of defects of sample 3 Average number of defects Example 1 0 1 0 0.33 Example 3 0 0 1 0.33 Example 4 1 2 1 1.33 Comparative Example 7 8 10 9 9.00 Comparative Example 8 22 19 25 22.00 Comparative Example 9 25 28 26 26.33

[0067] Comparing Example 1 and Comparative Example 9 separately, it can be seen that although the synergistic effect of triazine UVA and UVB absorbers can improve the anti-UV aging performance, their compatibility in the polyamide system is poor and significantly weaker than that of benzotriazole UVA absorbers, which can easily lead to appearance defects such as precipitation and whitening.

[0068] The average number of defects in Examples 1, 3, and 4 was significantly lower than that in Comparative Examples 7 and 8, indicating that the amount of UVA and UVB absorbers added has a crucial impact on the compatibility and stability of the polyamide material. When the total amount of both is less than 6 parts, the polyamide material maintains good compatibility, and surface defects are significantly reduced. However, when the amount added exceeds 6 parts, the interactions between the additives and between the additives and the substrate become more complex, easily leading to compatibility problems such as precipitation and whitening, resulting in a significant increase in the number of surface defects.

[0069] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An aging-resistant polyamide composition, characterized in that, It contains the following components in parts by weight: Polyamide 0-99 parts by weight, chopped glass fiber 0-60 parts by weight, antioxidant 0.01-1 parts by weight, ultraviolet light absorber 0.1-6 parts by weight, hindered amine light stabilizer 0.1-3 parts by weight, phosphonite / salt anti-aging agent 0.1-3 parts by weight, pigment 0.1-10 parts by weight; The ultraviolet light absorber is composed of UVA and UVB ultraviolet light absorbers, and the sum of the amounts of the UVA and UVB ultraviolet light absorbers is 0.1-6 parts by weight.

2. The aging-resistant polyamide composition according to claim 1, characterized in that, The UVA ultraviolet light absorber includes 2-(2H-benzotriazole-2)-4,6-di(1-methyl-1-phenylethyl)-phenol, which absorbs ultraviolet light at 300-400 nm and has an absorption peak at 343 nm. The UVB ultraviolet light absorber includes N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethylenediamide, which absorbs ultraviolet light in the 280-320 nm range and has an absorption peak of 298 nm.

3. The aging-resistant polyamide composition according to claim 1, characterized in that, The hindered amine light stabilizer includes one or a mixture of two or more of the following: poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester, N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-N,N'-dialdehyde hexamethylenediamine, and pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid). The phosphonite / salt anti-aging agents include one or a mixture of two or more of the following: trialkyl phosphite, tri(alkylaryl) phosphite, dialkylaryl phosphite, spirocyclic phosphonite, tris(2,4-di-tert-butylphenyl)phosphonite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphonite, antioxidant P-EPQ, and sodium phenylphosphonite.

4. The aging-resistant polyamide composition according to claim 1, characterized in that, The polyamide includes one or a mixture of two or more of PA46, PA56, PA66, PA6, PA612, PA610, PA1010, PA6I / 6T, PA6T / 6I, PA6T / 66, PA5T / 56, PA5T / 6T, PA10T, PA10T / 66, PA9T, PA12, PAMACM12, PAPACM12, PAMACMI / MACMT / MACM12; When measured with m-cresol as a solvent, the Ubbelohde relative viscosity of the polyamide is 1.4–2.0 or 1.4–1.

8.

5. The aging-resistant polyamide composition according to claim 1, characterized in that, The length of the chopped glass fiber is 3 to 4.5 mm; the diameter of the chopped glass fiber is 8 to 15 μm; the cross-section of the chopped glass fiber is circular or elliptical; and the aspect ratio of the chopped glass fiber is 1:3 to 1:

4.

6. The aging-resistant polyamide composition according to claim 1, characterized in that, The antioxidants include hindered phenolic antioxidants and phosphonates heat stabilizers; The amount of the hindered phenolic antioxidant is 0.1-0.5 parts by weight, and the amount of the phosphonite heat stabilizer is 0.1-0.5 parts by weight.

7. The aging-resistant polyamide composition according to claim 1, characterized in that, The pigment powder includes one or a mixture of two or more of the following: titanium dioxide, ultrafine zinc sulfide powder, carbon black powder, ultramarine pigment blue 29, ultramarine pigment violet 15, pigment brown 24, pigment orange 75, pigment orange 78, pigment red 265, organic pigment yellow 215, organic pigment blue 15:1, organic pigment blue 15:3, organic solvent red 52, organic solvent red 179, and organic solvent yellow 98, wherein the particle size of the pigment powder is not less than 10,000 mesh.

8. A method for preparing the aging-resistant polyamide composition according to claim 1, characterized in that, The process includes the following steps: mixing polyamide, antioxidant, UV absorber, hindered amine light stabilizer, phosphonite / salt anti-aging agent, and colorant evenly to form a mixture, and then adding the mixture into an extruder; During the extrusion process of the mixture, chopped glass fibers are added to the extruder by side feeding and simultaneously extruded at high temperature. After cooling, traction and pelletizing, a polyamide composition is obtained. The extrusion temperature of the extruder is 260-330℃.

9. The method for preparing an aging-resistant polyamide composition according to claim 8, characterized in that, When mixing raw materials, one or more components are pre-prepared into masterbatches and added to the extruder in the form of masterbatches.

10. An application based on an aging-resistant polyamide composition, characterized in that, The polyamide composition is used to prepare exterior parts and / or exterior identification parts.