A uvioresistant polyamide resin composition and a method for its production

Abstract

The application provides a kind of ultraviolet light resistant polyamide resin composition and its preparation method, the ultraviolet light resistant polyamide resin composition includes polyamide 66 resin and weather resistant master batch, the weather resistant master batch includes polyamide base material and anti-ultraviolet auxiliary agent, the anti-ultraviolet auxiliary agent includes light shielding agent, ultraviolet stabilizer and quenching agent;Three kinds of anti-ultraviolet auxiliary agent are selected by light shielding agent, ultraviolet stabilizer and quenching agent, and are mixed with polyamide 66 resin after being made into weather resistant master batch with polyamide base material preferentially, effectively improve the dispersion uniformity of anti-ultraviolet auxiliary agent in polyamide 66 resin, so that the obtained polyamide resin composition not only has excellent anti-ultraviolet aging performance, and appearance is good, also has good dimensional stability.

Description

Technical Field

[0001] This invention belongs to the field of polyamide resin technology, specifically relating to a UV-resistant polyamide resin composition and its preparation method. Background Technology

[0002] Polyamide resins possess excellent mechanical properties, chemical resistance, and molding and processing properties, making them widely used in various components such as automotive parts, electrical and electronic components, and industrial machinery parts. However, the presence of amide bonds results in strong water absorption and poor stability under high-temperature environments, making it impossible to avoid degradation caused by heat and light. This limits its application in certain structural materials.

[0003] Currently, the photo-thermal aging resistance of polyamides is mainly achieved through surface coating and bulk blending of polyamide materials. The former has advantages such as low cost and simple process, but it has disadvantages such as unsatisfactory anti-aging performance, weak durability, and easy shedding of modifiers. The latter has advantages such as good photo-thermal aging resistance and long-lasting effect, but it has disadvantages such as uneven dispersion of modifiers in the material, which makes polyamide film forming and processing difficult, and the mechanical properties of the film decrease significantly, resulting in poor performance.

[0004] CN115652466A discloses a synergistic compounded amidated light stabilizer for polyamide materials. This light stabilizer, formulated by compounding an ultraviolet absorber and a free radical scavenger, contains amidated groups highly compatible with polyamide materials. Therefore, both the ultraviolet absorber and the free radical scavenger can form strong polar bonds with polyamide molecules through amidation crosslinking, which helps reduce the probability of polyamide breakage and effectively improves the thermal stability of polyamide materials. Furthermore, the light stabilizer can absorb ultraviolet light or contain light-stabilizing groups, enhancing the anti-aging properties and light stability of polyamide materials during application. In addition, the ultraviolet quencher in the stabilizing agent can... The photothermal excitation energy of amide molecules is eliminated, returning them to a low-energy state where molecular bonds cannot be broken. Meanwhile, light-shielding agents can absorb or reflect ultraviolet light, effectively inhibiting aging and improving the photothermal stability of polyamide materials. However, the different properties and particle sizes of additives in the compounded light stabilizer result in varying dispersion effects within the polyamide system. Furthermore, the relatively small amounts of each additive in this compounded light stabilizer make it prone to aggregation during introduction into the system, and precise control of the addition amount is challenging. Therefore, uneven dispersion of the light stabilizer in the system may occur, affecting the final UV aging resistance of the product.

[0005] Therefore, developing a UV-resistant polyamide resin composition with uniform and stable properties remains a pressing technical problem in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a UV-resistant polyamide resin composition and its preparation method. By selecting three UV-resistant additives—a light-shielding agent, a UV stabilizer, and a quencher—and combining them with a polyamide base material to form a weather-resistant masterbatch before mixing it with polyamide 66 resin, the dispersion uniformity of the UV-resistant additives in the polyamide 66 resin is effectively improved. This results in a polyamide resin composition that not only has excellent UV aging resistance but also a good appearance.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a UV-resistant polyamide resin composition comprising polyamide 66 resin and weather-resistant masterbatch;

[0009] The weather-resistant masterbatch includes a polyamide base and UV-resistant additives;

[0010] The UV-blocking additives include light-shielding agents, UV stabilizers, and quenchers.

[0011] The UV-resistant polyamide resin composition provided by this invention includes polyamide 66 resin and weather-resistant masterbatch. The weather-resistant masterbatch includes a polyamide base material and UV-resistant additives, and the UV-resistant additives include a light-shielding agent, a UV stabilizer, and a quencher. This invention selects and combines three UV-resistant additives—a light-shielding agent, a UV stabilizer, and a quencher—in a coordinated manner. The invention first combines these three UV-resistant additives with the polyamide base material to form the weather-resistant masterbatch, and then combines the weather-resistant masterbatch with the polyamide 66 resin. This helps improve the uniform dispersion of the three UV-resistant additives in the polyamide 66 resin, resulting in good compatibility among the components in the obtained polyamide resin composition. Consequently, even with a low amount of UV-resistant additives, the obtained polyamide resin composition exhibits excellent UV aging resistance while maintaining a good product appearance.

[0012] Preferably, the mass of the weather-resistant masterbatch is 5-20% based on 100% of the mass of the UV-resistant polyamide resin composition, for example, 7%, 9%, 11%, 12%, 13%, 14%, 15%, 16%, 178%, 18%, 19%, or 20%.

[0013] Preferably, the polyamide base material is a long-chain polyamide resin with a carbon chain length greater than 12 (e.g., 13, 14, 15, 16, 17, 18, 19 or 20, etc.).

[0014] As a preferred technical solution of the present invention, the reason for limiting the carbon chain length of the polyamide base material to more than 12 is that a longer carbon chain length helps to reduce the density of hydrogen bonds between and within molecular chains, which can further improve the dimensional stability of the product.

[0015] Preferably, the long-chain polyamide resin includes any one or a combination of at least two of polyamide 610, polyamide 612, polyamide 510, or polyamide 512.

[0016] Preferably, the mass of the UV-resistant additive is 2-20% based on the total mass of the weather-resistant masterbatch as 100%, for example, 4%, 6%, 8%, 10%, 12%, 14%, 16% or 18%.

[0017] Preferably, based on the total mass of the UV-resistant polyamide resin composition as 100%, the mass of the light-shielding agent is 0.01 to 2%, for example, 0.05%, 0.1%, 0.5%, 1% or 1.5%, and more preferably 0.1 to 0.6%.

[0018] Preferably, the light-shielding agent comprises carbon black and / or aniline black.

[0019] Preferably, the light-shielding agent includes carbon black and aniline black.

[0020] Preferably, the mass ratio of carbon black to aniline black is (0.5-3):1, for example, 0.7:1, 0.9:1, 1.1:1, 1.3:1, 1.5:1, 1.7:1, 1.9:1, 2.1:1, 2.3:1, 2.5:1, 2.7:1 or 2.9:1, etc.

[0021] Preferably, based on 100% of the total mass of the UV-resistant polyamide resin composition, the content of the UV stabilizer is 0.05-0.8%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6% or 0.7%, and more preferably 0.1-0.4%.

[0022] Preferably, the ultraviolet stabilizer includes triazine ultraviolet stabilizers and / or benzotriazole ultraviolet stabilizers, such as any one or a combination of at least two of UV-1164, UV-1577, UV-P or UV-326.

[0023] Preferably, based on 100% of the total mass of the UV-resistant polyamide resin composition, the content of the quencher is 0.01 to 0.08%, such as 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, or 0.07%, and more preferably 0.012 to 0.048%.

[0024] Preferably, the quenching agent comprises any one or a combination of at least two of cobalt acetate, nickel acetate, or manganese acetate.

[0025] In a second aspect, the present invention provides a method for preparing the UV-resistant polyamide resin composition as described in the first aspect, the method comprising: mixing polyamide 66 resin and weather-resistant masterbatch, granulating, and obtaining the UV-resistant polyamide resin composition.

[0026] It should be noted that the preparation method provided by the present invention is a one-step method, that is, the weather-resistant masterbatch is directly added after the polymerization reaction of polyamide 66 resin is completed, and melt-blended with polyamide 66 resin to finally obtain a UV-resistant polyamide resin composition; this avoids the "contamination" of containers in the salt formation, concentration, and polymerization stages by the weather-resistant masterbatch and reduces the generation of transition materials.

[0027] Preferably, the polyamide 66 resin is polyamide 66 resin in a molten state.

[0028] As a preferred technical solution of the present invention, the synthesized molten polyamide 66 resin is directly mixed with the weather-resistant masterbatch, avoiding the process of slicing and remelting the finished polyamide 66 resin, which helps to maintain the excellent mechanical properties and good appearance of the polyamide 66 resin.

[0029] Preferably, the molten polyamide 66 resin is prepared by the following method, which includes the following steps:

[0030] (1) Adipic acid, hexamethylenediamine and water were reacted to form a salt to obtain a polyamide 66 salt solution;

[0031] (2) The polyamide 66 salt solution obtained in step (1) is concentrated to obtain a concentrated polyamide 66 salt solution.

[0032] (3) The concentrated polyamide 66 salt solution obtained in step (2) is subjected to prepolymerization and final polymerization in sequence to obtain the polyamide 66 resin in the molten state.

[0033] Preferably, the pH value of the polyamide 66 salt solution in step (1) is 7.1 to 7.7, such as 7.2, 7.3, 7.4, 7.5 or 7.6.

[0034] Preferably, the polyamide 66 salt in the polyamide 66 salt solution in step (1) has a mass percentage content of 50-65%, such as 52%, 54%, 56%, 58%, 60%, 62%, or 64%.

[0035] Preferably, the concentration process in step (2) is carried out in a concentration tank.

[0036] Preferably, the concentration process in step (2) is carried out at a temperature of 100 to 160°C, such as 110°C, 120°C, 130°C, 140°C, 150°C or 160°C.

[0037] Preferably, the mass percentage of polyamide 66 salt in the concentrated polyamide 66 salt solution in step (2) is 75-85%, such as 77%, 79%, 81% or 83%.

[0038] Preferably, the prepolymerization temperature in step (3) is 200-260°C, such as 210°C, 220°C, 230°C, 240°C or 250°C.

[0039] Preferably, the pressure of the prepolymerization in step (3) is 1.4 to 1.8 MPa, such as 1.45 MPa, 1.5 MPa, 1.55 MPa, 1.6 MPa, 1.65 MPa, 1.7 MPa or 1.75 MPa.

[0040] Preferably, after the prepolymerization in step (3) is completed, the step further includes sending the reaction product to a flash evaporator for expansion and depressurization.

[0041] Preferably, the outlet pressure of the flash evaporator is 0 to 0.1 MPa, for example, 0.02 MPa, 0.04 MPa, 0.06 MPa or 0.08 MPa.

[0042] Preferably, the outlet temperature of the flash evaporator is 260-280°C, such as 264°C, 268°C, 272°C, or 276°C.

[0043] Preferably, the final polymerization in step (3) includes prepolymerization and postpolymerization.

[0044] Preferably, the temperatures of the prepolymerization and / or postpolymerization are each independently 270–310°C, for example 280°C, 290°C, or 300°C.

[0045] Preferably, the prepolymerization pressure is 0 to 0.1 MPa, for example, 0.02 MPa, 0.04 MPa, 0.06 MPa or 0.08 MPa.

[0046] Preferably, the post-polymerization pressure is -0.05 to -0.001 MPa, for example -0.04 MPa, -0.03 MPa, -0.02 MPa, -0.01 MPa or -0.005 MPa.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention provides a UV-resistant polyamide resin composition comprising polyamide 66 resin and weather-resistant masterbatch; the weather-resistant masterbatch comprises a polyamide base material and UV-resistant additives; the UV-resistant additives include a light-shielding agent, a UV stabilizer, and a quencher; by selecting and combining the three UV-resistant additives—light-shielding agent, UV stabilizer, and quencher—and preferentially preparing the weather-resistant masterbatch with the polyamide base material before compounding it with the polyamide 66 resin, the dispersion uniformity of the UV-resistant additives in the polyamide 66 resin is effectively improved, resulting in a polyamide resin composition that not only has excellent UV aging resistance but also a good appearance and high surface gloss; by selecting long-chain polyamide as the weather-resistant masterbatch base material, the hydrogen bond density of long-chain polyamide is lower than that of polyamide systems such as polyamide 66 and polyamide 6, which is beneficial to improving the dimensional stability of the product. Detailed Implementation

[0049] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0050] Example 1

[0051] A UV-resistant polyamide resin composition comprising 90% and 10% by weight of polyamide 66 resin and weather-resistant masterbatch, respectively;

[0052] The weather-resistant masterbatch includes polyamide 612 resin (DuPont, Zytel 158) and UV-resistant additives with a mass percentage of 90.8% and 9.2%, respectively.

[0053] The UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164 and manganese acetate in a mass ratio of 0.4:0.2:0.3:0.02.

[0054] The method for preparing the UV-resistant polyamide resin composition provided in this embodiment includes the following steps:

[0055] (1) Salt refining: Adipic acid, hexamethylenediamine and water in a mass ratio of 1:1.2:2.1 are added to a salt forming tank to carry out a salt forming reaction to obtain a polyamide 66 salt solution. The pH value of the polyamide 66 salt solution is 7.2 and the mass percentage content is 55%.

[0056] (2) Concentration: The polyamide 66 salt solution obtained in step (1) is added to a concentration tank for concentration. The temperature of the concentration tank is 145℃, and a concentrated polyamide 66 salt solution with a mass percentage of 75% is obtained.

[0057] (3) Prepolymerization: The concentrated polyamide 66 salt solution obtained in step (2) is added to the reactor for prepolymerization by drainage. The temperature of the reactor is 250°C and the pressure is 1.6 MPa. Then the material is sent to the flash evaporator for expansion and depressurization. The outlet pressure of the flash evaporator is 0.05 MPa and the outlet temperature is 270°C.

[0058] (4) Post-polymerization: The material obtained in step (3) is sent to the prepolymerizer to fully remove the water in the system. The pressure of the prepolymerizer is 0.05MPa and the temperature is 275℃. Then the material is sent to the postpolymerizer. The vacuum system is evacuated. The pressure in the postpolymerizer is -0.05MPa and the temperature is 275℃ to obtain molten polyamide 66 resin.

[0059] (5) Modification: The weather-resistant masterbatch is melted and directly added to the molten polyamide 66 resin obtained in step (4) for blending. After the blending is completed, the mixture is extruded through a casting strip to form a strip, and then granulated with cooling water to obtain the UV-resistant polyamide resin composition.

[0060] Example 2

[0061] A UV-resistant polyamide resin composition comprising 90% and 10% by weight of polyamide 66 resin and weather-resistant masterbatch, respectively;

[0062] The weather-resistant masterbatch includes polyamide 612 resin chips (DuPont, Zytel 158) and UV-resistant additives with a mass percentage of 96.6% and 3.4%, respectively.

[0063] The UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164 and cobalt acetate in a mass ratio of 0.1:0.1:0.1:0.04.

[0064] The preparation method of the UV-resistant polyamide resin composition provided in this embodiment is the same as that in Example 1.

[0065] Example 3

[0066] A UV-resistant polyamide resin composition comprising 90% and 10% by weight of polyamide 66 resin and weather-resistant masterbatch, respectively;

[0067] The weather-resistant masterbatch includes polyamide 612 resin chips (DuPont, Zytel 158) and UV-resistant additives with a mass percentage of 95.2% and 4.8%, respectively.

[0068] The UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-326, and manganese acetate in a mass ratio of 0.03:0.03:0.4:0.02.

[0069] The preparation method of the UV-resistant polyamide resin composition provided in this embodiment is the same as that in Example 1.

[0070] Example 4

[0071] A UV-resistant polyamide resin composition comprising 95% and 5% by weight of polyamide 66 resin and weather-resistant masterbatch, respectively.

[0072] The weather-resistant masterbatch includes polyamide 612 resin chips (DuPont, Zytel 158) and UV-resistant additives with a mass percentage of 81.6% and 18.4%, respectively.

[0073] The UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164 and manganese acetate in a mass ratio of 0.4:0.2:0.3:0.02.

[0074] The preparation method of the UV-resistant polyamide resin composition provided in this embodiment is the same as that in Example 1.

[0075] Example 5

[0076] A UV-resistant polyamide resin composition comprising 80% and 20% by weight of polyamide 66 resin and weather-resistant masterbatch, respectively;

[0077] The weather-resistant masterbatch includes polyamide 612 resin chips (DuPont, Zytel 158) and UV-resistant additives with a mass percentage of 95.4% and 4.6%, respectively.

[0078] The UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164 and manganese acetate in a mass ratio of 0.4:0.2:0.3:0.02.

[0079] The preparation method of the UV-resistant polyamide resin composition provided in this embodiment is the same as that in Example 1.

[0080] Example 6

[0081] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, UV stabilizer UV-1164, and manganese acetate in a mass ratio of 0.6:0.3:0.02. Other substances, dosages, and preparation methods are the same as in Example 1.

[0082] Example 7

[0083] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive consists of aniline black, UV stabilizer UV-1164, and manganese acetate in a mass ratio of 0.6:0.3:0.02. Other substances, dosages, and preparation methods are the same as in Example 1.

[0084] Example 8

[0085] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164, and manganese acetate in a mass ratio of 0.006:0.003:0.8:0.111. Other substances, dosages, and preparation methods are the same as in Example 1.

[0086] Example 9

[0087] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164, and manganese acetate in a mass ratio of 0.57:0.28:0.04:0.03. Other substances, dosages, and preparation methods are the same as in Example 1.

[0088] Example 10

[0089] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, aniline black, UV stabilizer UV-1164, and manganese acetate in a mass ratio of 0.41:0.2:0.305:0.005. Other substances, dosages, and preparation methods are the same as in Example 1.

[0090] Example 11

[0091] A UV-resistant polyamide resin composition differs from Example 1 only in that polyamide 66 resin chips (Huafeng Group Co., Ltd., EP158) are used instead of polyamide 612 resin chips, while other substances, dosages and preparation methods are the same as in Example 1.

[0092] Comparative Example 1

[0093] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive consists of UV stabilizer UV-1164 and manganese acetate in a mass ratio of 0.86:0.06. Other substances, dosages, and preparation methods are the same as in Example 1.

[0094] Comparative Example 2

[0095] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, aniline black, and manganese acetate in a mass ratio of 0.59:0.3:0.03, while the other substances, dosages, and preparation methods are the same as in Example 1.

[0096] Comparative Example 3

[0097] A UV-resistant polyamide resin composition differs from Example 1 only in that the UV-resistant additive is composed of carbon black, aniline black, and UV stabilizer UV-1164 in a mass ratio of 0.41:0.2:0.31. Other substances, dosages, and preparation methods are the same as in Example 1.

[0098] Comparative Example 4

[0099] A polyamide resin composition comprising polyamide 66 resin, carbon black, aniline black, manganese acetate and ultraviolet stabilizer UV-1164 in weight percentages of 90.8%, 0.4%, 0.2%, 0.02% and 0.3%, respectively;

[0100] The method for preparing the polyamide resin composition provided in this comparative example includes the following steps:

[0101] (1) Salt refining: Adipic acid, hexamethylenediamine and water in a mass ratio of 1:1.2:2.1 are added to a salt forming tank to carry out a salt forming reaction to obtain a polyamide 66 salt solution. The pH value of the polyamide 66 salt solution is 7.2 and the mass percentage content is 55%.

[0102] (2) Concentration: The polyamide 66 salt solution obtained in step (1) is added to a concentration tank for concentration. The temperature of the concentration tank is 145℃, and a concentrated polyamide 66 salt solution with a mass percentage of 75% is obtained.

[0103] (3) Prepolymerization: The concentrated polyamide 66 salt solution obtained in step (2) is added to the reactor for drainage prepolymerization. The reactor temperature is 250℃ and the pressure is 1.6MPa. Then the material is sent to the flash evaporator for expansion and depressurization. The outlet pressure of the flash evaporator is 0.05MPa and the outlet temperature is 270℃.

[0104] (4) Post-polymerization: The material obtained in step (3) is sent to the prepolymerizer to fully remove the water in the system. The pressure of the prepolymerizer is 0.05MPa and the temperature is 275℃. Then the material is sent to the postpolymerizer. The vacuum system is evacuated. The pressure in the postpolymerizer is -0.05MPa and the temperature is 275℃ to obtain molten polyamide 66 resin.

[0105] (5) Modification: Carbon black, aniline black, manganese acetate and UV stabilizer UV-1164 are added to the feeding equipment and directly mixed with molten polyamide 66 resin. After mixing, the mixture is extruded through a casting strip to form a strip, which is then granulated with cooling water to obtain the polyamide resin composition.

[0106] Performance testing:

[0107] (1) Dimensional change rate: A 60×60×3mm sheet was obtained by injection molding. An initial length of 50mm was marked on the transverse direction of the sheet. After UV aging for 1000h according to the method provided in GB / T 16422.3-2022, the dimensional change rate of the sheet was measured by measuring the marked length L. The calculation formula is: △L=(L-50) / L×100%.

[0108] (2) Tensile strength: Tensile specimens were obtained by injection molding according to GB / T 17037.1. The initial tensile strength and tensile strength after aging of the specimens were tested according to GB / T 1040.1. Ultraviolet aging was carried out according to GB / T 16422.3-2022.

[0109] (3) Dispersion effect: The L value of the product was measured by X-rite color i5 desktop spectrophotometer (color difference meter). The difference between the maximum and minimum L values ​​of the 6 sample test slices was used to characterize the dispersion uniformity. The smaller the difference, the better the uniformity, and vice versa.

[0110] (4) △E: The initial E1 value and the E2 value after 1000h UV aging of the product are measured by X-rite color i5 desktop spectrophotometer (color difference meter). The difference between E2 and E1 is the color difference value △E. The smaller the difference, the smaller the color difference change, and vice versa.

[0111] The polyamide compositions provided in Examples 1-11 and Comparative Examples 1-4 were tested according to the above test methods, and the test results are shown in Table 1:

[0112] Table 1

[0113]

[0114]

[0115] According to the data in Table 1:

[0116] The UV-resistant polyamide resin composition provided by the present invention is achieved by mixing three specific UV-resistant additives with weather-resistant masterbatch, which gives the polyamide resin composition excellent UV aging resistance, dimensional stability and good product appearance.

[0117] Specifically, the dimensional change rate of the polyamide resin compositions obtained in Examples 1-5 was 1.681-1.776%, the initial tensile strength was 73.6-77.6 MPa, the tensile strength after 500 hours of UV aging was still as high as 62.3-68.4 MPa, and the tensile strength after 1000 hours of UV aging was still as high as 50.8-55.3 MPa, indicating that the polyamide resin compositions provided in Examples 1-5 have excellent UV resistance. Furthermore, the dispersion test showed that the range of L values ​​was only 0.8-1.4, indicating that the polyamide resin compositions provided in Examples 1-5 had good dispersion effect. Finally, the color difference before and after UV aging was only ΔE of 1.2-2.8, indicating that the polyamide resin compositions provided in Examples 1-5 still had good appearance after UV aging.

[0118] A comparison of the data from Example 1 with Comparative Examples 1-3 shows that the absence of any of the light-shielding agent, ultraviolet stabilizer, or quencher in the polyamide resin composition leads to a decrease in tensile strength and an increase in color difference after ultraviolet aging.

[0119] Comparing the data from Example 1 and Comparative Example 4, it can be seen that the L-value of the polyamide resin composition obtained by directly mixing the light shielding agent, ultraviolet stabilizer, quencher and polyamide 66 resin instead of preparing weather-resistant masterbatch has a very large difference, indicating that the dispersion effect of the three anti-ultraviolet additives in the composition is poor.

[0120] Finally, comparing the data from Examples 1 and 6-11, it can be seen that the absence of aniline black and carbon black as light shielding agents, the mass percentage of the three UV-resistant additives in the polyamide resin composition, and the carbon chain length of the polyamide matrix in the weather-resistant masterbatch, will also have an adverse effect on the UV resistance of the final polyamide resin composition.

[0121] The applicant declares that this invention illustrates a UV-resistant polyamide resin composition and its preparation method through the above embodiments, but the invention is not limited to the above embodiments, that is, it does not mean that the invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials of the product, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. An ultraviolet light resistant polyamide resin composition, characterized by comprising: The ultraviolet light resistant polyamide resin composition comprises a polyamide 66 resin and a weather resistant master batch; The weather resistant master batch comprises a polyamide base and an ultraviolet light resistant auxiliary agent; The ultraviolet light resistant auxiliary agent is composed of a light shielding agent, an ultraviolet light stabilizer and a quencher; The mass of the light shielding agent is 0.1-2% based on the total mass of the ultraviolet light resistant polyamide resin composition. The light shielding agent comprises carbon black and / or aniline black. The content of the ultraviolet light stabilizer is 0.05-0.8% based on the total mass of the ultraviolet light resistant polyamide resin composition. The ultraviolet light stabilizer comprises a triazine ultraviolet light stabilizer and / or a benzotriazole ultraviolet light stabilizer. The content of the quencher is 0.01-0.06% based on the total mass of the ultraviolet light resistant polyamide resin composition. The quencher comprises any one or a combination of at least two of cobalt acetate, nickel acetate or manganese acetate.

2. The ultraviolet light resistant polyamide resin composition according to claim 1, characterized in that, The mass of the weather resistant master batch is 5-20% based on the mass of the ultraviolet light resistant polyamide resin composition.

3. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The polyamide base is a long carbon chain polyamide resin with a carbon chain length higher than 12.

4. The ultraviolet resistant polyamide resin composition according to claim 3, wherein The long carbon chain polyamide resin comprises any one or a combination of at least two of polyamide 610, polyamide 612, polyamide 510 or polyamide 512.

5. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The mass of the ultraviolet light resistant auxiliary agent is 2-20% based on the total mass of the weather resistant master batch.

6. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The mass of the light shielding agent is 0.1-0.6% based on the total mass of the ultraviolet light resistant polyamide resin composition.

7. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The light shielding agent comprises carbon black and aniline black.

8. The ultraviolet resistant polyamide resin composition according to claim 7, wherein The mass ratio of the carbon black to the aniline black is (0.5-3):

1.

9. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The content of the ultraviolet light stabilizer is 0.1-0.4% based on the total mass of the ultraviolet light resistant polyamide resin composition.

10. The ultraviolet light resistant polyamide resin composition according to claim 1, wherein The content of the quencher is 0.012-0.048% based on the total mass of the ultraviolet light resistant polyamide resin composition.

11. A method for producing the ultraviolet resistant polyamide resin composition according to any one of claims 1 to 10, characterized by, The preparation method comprises mixing the polyamide 66 resin and the weather resistant master batch, and granulating to obtain the ultraviolet light resistant polyamide resin composition.

12. The method of claim 11, wherein, The polyamide 66 resin is a polyamide 66 resin in a molten state.

13. The method of claim 12, wherein, The polyamide 66 resin in a molten state is prepared by a method comprising the following steps: (1) performing a salt reaction on adipic acid, hexamethylene diamine and water to obtain a polyamide 66 salt solution; (2) performing concentration treatment on the polyamide 66 salt solution obtained in step (1) to obtain a concentrated polyamide 66 salt solution; (3) sequentially performing prepolymerization and final polymerization on the concentrated polyamide 66 salt solution obtained in step (2) to obtain the polyamide 66 resin in a molten state.

14. The method of claim 13, wherein, The pH value of the polyamide 66 salt solution in step (1) is 7.1-7.

7.

15. The preparation method according to claim 13, characterized in that, The mass percentage content of the polyamide 66 salt in the polyamide 66 salt solution in step (1) is 50-65%.

16. The method of claim 13, wherein, The concentration treatment in step (2) is performed in a concentration tank.

17. The method of claim 13, wherein, The temperature of the concentration treatment in step (2) is 100-160℃.

18. The method of claim 13, wherein, The mass percentage of the polyamide 66 salt in the concentrated polyamide 66 salt solution in step (2) is 75-85%.

19. The method of claim 13, wherein, The temperature of the prepolymerization in step (3) is 200-260°C.

20. The method of claim 13, wherein, The pressure of the prepolymerization in step (3) is 1.4-1.8 MPa.

21. The method of claim 13, wherein, The prepolymerization in step (3) further comprises a step of sending the reaction product to a flash evaporator for expansion and pressure relief after the prepolymerization is completed.

22. The method of claim 21, wherein, The outlet pressure of the flash evaporator is 0-0.1 MPa.

23. The preparation method according to claim 21, characterized in that, The outlet temperature of the flash evaporator is 260-280°C.

24. The method of claim 13, wherein, The final polymerization in step (3) comprises a pre-polymerization and a post-polymerization.

25. The method of claim 24, wherein, The temperature of the pre-polymerization and the post-polymerization is independently 270-310°C.

26. The method of claim 24, wherein, The pressure of the pre-polymerization is 0-0.1 MPa.

27. The preparation method according to claim 24, characterized in that, The pressure of the post-polymerization is -0.05--0.001 MPa.

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