Phenol-yellowing-resistant nylon 12 composition as well as preparation method and application thereof

Abstract

The invention discloses a phenolic yellowing resistant nylon 12 composition as well as a preparation method and application thereof. The nylon 12 composition is prepared from the following components in parts by weight: 100 parts of nylon 12 resin, 2 to 10 parts of dobby nylon 12 phenol-resistant yellowing agent, 0.1 to 0.5 part of lubricant and 0.1 to 0.5 part of antioxidant, wherein the dobby nylon 12 phenolic yellowing resistant agent is prepared by reacting a carboxyl-terminated dobby nylon 12 oligomer with a sulfamic acid compound. In the nylon 12 composition provided by the invention, functional groups in the phenolic yellowing resistant auxiliary agent are more washable and anti-migration, and can play a long-acting phenolic yellowing resistant role.

Description

Technical Field

[0001] The invention relates to a nylon 12 composition, in particular to a nylon 12 composition resistant to phenol yellowing and a preparation method and application thereof. Background Art

[0002] Phenolic yellowing is a common yellowing in textile materials (especially nylon fabrics), which refers to the phenomenon that textile materials turn yellow due to the action of nitrogen oxides or phenolic compounds. The main reason for this phenomenon is that sterically hindered phenolic antioxidants are commonly used in packaging materials, such as BHT (2,6-di-tert-butyl-p-cresol), which has low solubility in polyethylene or polypropylene packaging materials and is easy to volatilize. It is easy to diffuse to the surface of the packaging material and react with nitrogen oxides (NOx) in the air to generate 2,6-di-tert-butyl-4-nitrophenol (DTNP), which forms a yellow substance under alkaline conditions, causing the fabric to turn yellow.

[0003] Treatment with phenolic yellowing inhibitors is an effective way to improve the phenolic yellowing resistance of nylon fabrics. Conventional phenolic yellowing inhibitors (such as alkyl sulfonates) are added during the fabric finishing process, but there are compatibility issues when used in the same bath with other finishing products. The treatment process is cumbersome, which brings inconvenience to production. In addition, the effective ingredients for phenolic yellowing resistance only exist on the surface of the fabric and are easily migrated from the surface of the fabric, making it difficult for the phenolic yellowing resistance effect to last.

[0004] Patent CN108795028A adds organic acid to nylon resin, claiming that its phenol yellow resistance can be effectively improved by adjusting the pH of the resin, but the organic acid is easy to precipitate and migrate, and the durability of phenol yellow resistance is poor. Patent CN111733599A uses sodium dodecyl phenyl ether sulfate, which can ionize dodecyl phenyl ether sulfate anions under acidic conditions, as a nylon fabric treatment agent. The ionized dodecyl phenyl ether sulfate anions can combine with the amino and amide groups of nylon fibers, thereby achieving the purpose of blocking the amino and amide groups, allowing nylon fibers to obtain a more durable resistance to phenol yellowing. However, this method still requires cumbersome sodium dodecyl phenyl ether sulfate post-treatment procedures, and the production efficiency is low. Patent CN114163632A starts with copolyamide monomers, and by adding carboxylated sulfonic acid compounds as end-capping agents during the polymerization stage, the sulfonic acid group can capture and react with free amines and amino and nitrogen-containing structures at the ends of the molecular chain, and adjust its addition amount to control the amino content, thereby obtaining a copolyamide with more durable yellowing resistance. However, due to the limitation of the molecular weight of the polymer product, the amount of carboxylated sulfonic acid compound with end-capping effect added is limited. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a nylon 12 composition resistant to phenolic yellowing, and a preparation method and application thereof. The present invention improves the compatibility with the nylon 12 resin matrix by grafting sulfonic acid groups into nylon 12 oligomers as phenolic yellowing-resistant additives, and the amount of phenolic yellowing-resistant additives added is more flexible, which can achieve a long-term phenolic yellowing-resistant effect; at the same time, the nylon 12 oligomer is adjusted to a branched structure, which not only increases the grafting amount of sulfonic acid groups, but also helps to improve the fluidity and mechanical properties of the nylon 12 resin.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A nylon 12 composition resistant to phenolic yellowing, comprising the following components in parts by weight:

[0008] 100 parts of nylon 12 resin,

[0009] 2-10 parts of multi-arm nylon 12 phenol yellowing agent,

[0010] Lubricant 0.1-0.5 parts,

[0011] Antioxidant 0.1-0.5 parts;

[0012] The multi-arm nylon 12 phenol yellowing resistance agent is prepared by reacting carboxyl-terminated multi-arm nylon 12 oligomers with aminosulfonic acid compounds.

[0013] In some embodiments, the number average molecular weight of the carboxyl-terminated multi-arm nylon 12 oligomer is 1500-8000;

[0014] Preferably, the carboxyl-terminated multi-arm nylon 12 oligomer is prepared by reacting a dicarboxyl-terminated nylon 12 oligomer and a polyamine branching agent; the dicarboxyl-terminated nylon 12 oligomer preferably has a number average molecular weight of 500-2000; the polyamine branching agent is preferably one or more of benzene-1,2,3-triamine, 1,2,4,5-benzenetetramine, pentaminebenzene, and benzene-1,2,3,4,5,6-hexamine;

[0015] Preferably, the added amounts of the dicarboxyl-terminated nylon 12 oligomer and the polyamine branching agent are 2:(0.9-1.1) in terms of the molar ratio of carboxyl group to amine group.

[0016] Preferably, the reaction conditions of the dicarboxyl-terminated nylon 12 oligomer and the polyamine branching agent are: a reaction temperature of 220-240° C., a negative pressure of 80-90 KPa, and a reaction time of 30-60 min.

[0017] In some embodiments, the dicarboxyl-terminated nylon 12 oligomer is prepared by melt polycondensation of lauryl lactam and a dibasic acid-based end-capping agent in the presence of a catalyst;

[0018] Preferably, the dibasic acid capping agent is selected from one or more of adipic acid, sebacic acid, and dodecanedioic acid;

[0019] Preferably, the catalyst is at least one of phosphoric acid, hypophosphorous acid and sodium hypophosphite, and the added amount thereof is preferably 0.005-0.02% of the weight of the dicarboxyl-terminated nylon 12 oligomer.

[0020] Preferably, the reaction conditions of the laurolactam and the dibasic acid end-capping agent are: firstly heating to 240-290°C for reaction for 2-6h, then depressurizing to 5-10kPa, cooling to 220-240°C, evacuating to negative pressure of 80-90KPa, and reacting for 60-180min;

[0021] Preferably, the laurolactam and the dibasic acid end-capping agent are mixed and reacted in water, and the amount of water used is 5-15% of the mass of laurolactam.

[0022] In some embodiments, the aminosulfonic acid compound is selected from one or more of aminosulfonic acid, aminomethanesulfonic acid, p-aminobenzenesulfonic acid, 4-aminotoluene-3-sulfonic acid, 2-aminobenzenesulfonic acid, and 3-aminopropanesulfonic acid;

[0023] Preferably, the added amounts of the carboxyl-terminated multi-arm nylon 12 oligomer and the aminosulfonic acid compound are 1:(0.9-1.1) in terms of the molar ratio of the carboxyl group to the amine group.

[0024] Preferably, the reaction conditions of the carboxyl-terminated multi-arm nylon 12 oligomer and the aminosulfonic acid compound are: reaction temperature of 220-240° C., negative pressure of 80-90 Kpa, and reaction time of 30-60 min.

[0025] In some embodiments, the relative viscosity of the nylon 12 resin is 1.50-2.50 (m-cresol as solvent, concentration of 0.005 g / ml), preferably 1.60-2.20.

[0026] In some embodiments, the lubricant is selected from one of ethylene bis stearamide (EBS), oleamide, silicone oil, and paraffin.

[0027] In some embodiments, the antioxidant is a compound that does not contain a phenolic hydroxyl group, preferably one or more of the antioxidant SEED, antioxidant TFB-117, antioxidant 168, and antioxidant PEPQ.

[0028] The present invention also provides a method for preparing the phenol yellowing resistant nylon 12 composition as described above, comprising a process of mixing nylon 12 resin, a multi-arm nylon 12 phenol yellowing resistant agent, a lubricant, and an antioxidant at high speed, and extruding, wherein the stirring speed of the high-speed mixing is 50-500 rpm and the mixing time is 10-30 min; the extrusion temperature is 180-280° C., and the screw speed is 100-500 rpm.

[0029] The present invention also provides an application of the phenol yellowing-resistant nylon 12 composition as described above in textile products, especially in white fabrics.

[0030] In the nylon 12 composition provided by the present invention, the functional groups in the phenol yellowing resistance auxiliary agent are more resistant to water washing and migration, and can play a long-lasting role in phenol yellowing resistance. Moreover, the phenol yellowing resistance auxiliary agent uses a multi-arm nylon 12 oligomer as a matrix and can form a eutectic structure with a nylon 12 resin system, has good compatibility and a stable structure, and can improve the fluidity and mechanical properties of the nylon 12 resin, thereby having broad application prospects. DETAILED DESCRIPTION

[0031] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0032] The main test methods used in the following embodiments of the present invention are as follows:

[0033] (1) Number average molecular weight: tested by gel permeation chromatography (GPC) system, equipment model is WATERS1515;

[0034] (2) Phenolic yellowing resistance test: The nylon 12 composition was prepared into a standard sample with reference to the phenolic yellowing resistance test standard GB / T 29778, and the phenolic yellowing resistance level before and after high-temperature cooking was tested (graded from 1 to 5 from low to high) to characterize the long-term phenolic yellowing resistance performance;

[0035] The high temperature cooking conditions are: cooking the sample in pure water at 80°C, taking it out after 24 hours, vacuum drying it at 80°C, and testing its performance.

[0036] (3) Tensile strength: tested according to the method in ISO 527;

[0037] (4) Room temperature Charpy impact strength: tested according to the method in ISO 179.

[0038] [Preparation Example 1]

[0039] 2kg of laurolactam (Wanhua Chemical), 700g of adipic acid (Hualu Hengsheng), 0.1g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 100g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The reactor was heated to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening reaction was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. The reactor was then evacuated to -90kPa for 60min to complete the melt polycondensation to obtain dicarboxyl-terminated nylon 12 oligomers. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomers was 560. 197 g of benzene-1,2,3-triamine (Beijing Inokai Technology Co., Ltd.) was added, and the vacuum reaction was continued at -90 kPa for 30 min. The vacuum was stopped, nitrogen was added to 100 kPa, stirring was stopped, and the temperature was lowered to 30°C to obtain a carboxyl-terminated multi-arm nylon 12 oligomer (BPA-1) with a detected number average molecular weight of 1760.

[0040] 532 g of aminomethanesulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to the reactor of the above-mentioned carboxyl-terminated multi-arm nylon 12 oligomer (BPA-1), and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the mixture was evacuated to -90 kPa and reacted for 30 minutes. The mixture was then towed, water-cooled, and pelletized to obtain multi-arm nylon 12 phenol yellowing agent resistant pellets (APY-PA-1).

[0041] [Preparation Example 2]

[0042] 2kg of laurolactam (Wanhua Chemical), 1100g of sebacic acid (Shanghai Kaisai Chemical Co., Ltd.), 0.1g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 100g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The temperature was raised to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. The reaction was then evacuated to -90kPa and allowed to react for 120min to complete the melt polycondensation to obtain dicarboxyl-terminated nylon 12 oligomers. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomers was 560. Add 229 g of benzene-1,2,3,4,5,6-hexamine (Beijing Inokai Technology Co., Ltd.), continue to maintain a vacuum reaction at -90 kPa for 30 min, stop vacuuming, add nitrogen to 100 kPa, stop stirring and cool to 30°C to obtain carboxyl-terminated multi-arm nylon 12 oligomer (BPA-2), and the detected number average molecular weight is 3560.

[0043] 942 g of p-aminobenzenesulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to the reactor of the above-mentioned carboxyl-terminated multi-arm nylon 12 oligomer (BPA-2), and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the mixture was evacuated to -90 kPa and reacted for 30 minutes. The reaction was then carried out by traction, water cooling, and pelletizing to obtain multi-arm nylon 12 phenol yellowing agent resistant pellets (APY-PA-2).

[0044] [Preparation Example 3]

[0045] 2kg of laurolactam (Wanhua Chemical), 500g of sebacic acid (Shanghai Kaisai Chemical Co., Ltd.), 0.2g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 200g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The reactor was heated to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. The reactor was then evacuated to -90kPa and reacted for 120min to complete the melt polycondensation to obtain dicarboxyl-terminated nylon 12 oligomers. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomers was 1010. 108 g of 1,2,4,5-benzenetetramine (Beijing Inokai Technology Co., Ltd.) was added, and the reaction was continued at -90 kPa for 60 min. The vacuum was stopped, nitrogen was added to 100 kPa, stirring was stopped, and the temperature was lowered to 30°C to obtain a carboxyl-terminated multi-arm nylon 12 oligomer (BPA-3) with a detected number average molecular weight of 4140.

[0046] 463 g of 4-aminotoluene-3-sulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to the reactor of the above-mentioned carboxyl-terminated multi-arm nylon 12 oligomer (BPA-3), and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the reaction temperature was evacuated to -90 kPa. After reaction for 30 minutes, the reactor was pulled, water-cooled, and pelletized to obtain multi-arm nylon 12 phenol yellowing agent resistant pellets (APY-PA-3).

[0047] [Preparation Example 4]

[0048] 2kg of laurolactam (Wanhua Chemical), 340g of adipic acid (Hualu Hengsheng), 0.2g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 200g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The reactor was heated to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening reaction was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. The reactor was then evacuated to -90kPa and reacted for 120min to complete the melt polycondensation to obtain dicarboxyl-terminated nylon 12 oligomers. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomers was 1003. Add 98 g of benzene-1,2,3,4,5,6-hexamine (Beijing Inokai Technology Co., Ltd.), continue to maintain -90 kPa for 60 min, stop vacuuming, add nitrogen to 100 kPa, stop stirring and cool to 30°C to obtain carboxyl-terminated multi-arm nylon 12 oligomer (BPA-4), and the detected number average molecular weight is 6170.

[0049] 403 g of 2-aminobenzenesulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to a reactor containing carboxyl-terminated multi-arm nylon 12 oligomer (BPA-4), and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the reaction was evacuated to -90 kPa for 60 minutes. After traction, water cooling, and pelletization, multi-arm nylon 12 phenol yellowing agent resistant pellets (APY-PA-4) were obtained.

[0050] [Preparation Example 5]

[0051] 2kg of laurolactam (Wanhua Chemical), 265g of dodecanedioic acid (Shanghai MacLean Biochemical Technology Co., Ltd.), 0.4g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 300g of ultrapure water were added to the reactor, and the nitrogen was replaced five times. The temperature was raised to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released, and then the pressure was evacuated to -90kPa and reacted for 180min to complete the melt polycondensation to prepare the dicarboxyl-terminated nylon 12 oligomer. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomer was 1960. Add 50 g of 1,2,4,5-benzenetetramine (Beijing Inokai Technology Co., Ltd.), continue to maintain -90 kPa for 60 min, stop vacuuming, add nitrogen to 100 kPa, stop stirring and cool to 30°C to obtain carboxyl-terminated multi-arm nylon 12 oligomer (BPA-5), and the detected number average molecular weight is 7970.

[0052] 160 g of 3-aminopropane sulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to the reactor of the above-mentioned carboxyl-terminated multi-arm nylon 12 oligomer (BPA-5), and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the temperature was evacuated to -90 kPa for 60 minutes. After traction, water cooling, and pelletization, multi-arm nylon 12 phenol yellowing agent resistant pellets (APY-PA-5) were obtained.

[0053] [Comparative Preparation Example 1]

[0054] 2kg of laurolactam (Wanhua Chemical), 700g of adipic acid (Hualu Hengsheng), 0.1g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 100g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The reactor was heated to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening reaction was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. The reactor was then evacuated to -90kPa for 60min to complete the melt polycondensation to obtain dicarboxyl-terminated nylon 12 oligomers. After sampling and testing, the number average molecular weight of the dicarboxyl-terminated nylon 12 oligomers was 560.

[0055] 532 g of aminomethanesulfonic acid (Shanghai MacLean Biochemical Technology Co., Ltd.) was added to the above-mentioned reactor containing dicarboxyl-terminated nylon 12 oligomer, and the atmosphere was replaced with nitrogen five times. The temperature was raised to 230°C, and the reaction was evacuated to -90 kPa. After reaction for 30 minutes, the nylon 12 phenol yellowing agent resistant pellets (APY-PA-6) were obtained by traction, water cooling and pelletizing.

[0056] [Example 1]

[0057] The nylon 12 composition was prepared as follows:

[0058] 5kg nylon 12 (Wanhua Chemical, L1000, relative viscosity 1.60), 100g APY-PA-1, 5g lubricant EBS (Kao, Japan), 15g antioxidant TFB-117 (Clariant) were added to a high-speed mixer and mixed at a speed of 50rpm for 20min to obtain a mixed material. The mixed material was melt-extruded by a twin-screw extruder with an aspect ratio of 42, water-cooled, pelletized, and dried to obtain nylon 12 composite pellets. The screw speed was 150rpm, and the temperature from the feeding section to the die was set to 180-220°C.

[0059] [Example 2]

[0060] The nylon 12 composition was prepared as follows:

[0061] 5kg nylon 12 (Wanhua Chemical, L2000, relative viscosity 1.90), 500g APY-PA-2, 15g lubricant EBS (Kao, Japan), 5g antioxidant TFB-117 (Clariant) were added to a high-speed mixer and mixed at a speed of 300rpm for 20min to obtain a mixed material. The mixed material was melt-extruded by a twin-screw extruder with an aspect ratio of 42, water-cooled, pelletized, and dried to obtain nylon 12 composite pellets. The screw speed was 250rpm, and the temperature from the feeding section to the die was set to 180-220°C.

[0062] [Example 3]

[0063] The nylon 12 composition was prepared as follows:

[0064] 5kg nylon 12 (Wanhua Chemical, L3000, relative viscosity 2.20), 250g APY-PA-3, 15g lubricant EBS (Kao, Japan), 25g antioxidant TFB-117 (Clariant) were added to a high-speed mixer and mixed at a speed of 500rpm for 20min to obtain a mixed material. The mixed material was melt-extruded by a twin-screw extruder with an aspect ratio of 42, water-cooled, pelletized, and dried to obtain nylon 12 composite pellets. The screw speed was 450rpm, and the temperature from the feeding section to the die was set to 180-220°C.

[0065] [Example 4]

[0066] The nylon 12 composition was prepared as follows:

[0067] 5kg nylon 12 (Wanhua Chemical, L2000, relative viscosity 1.90), 250g APY-PA-4, 25g lubricant EBS (Kao, Japan), 15g antioxidant 168 (Li'anlong New Materials Co., Ltd.) were added to a high-speed mixer and mixed at a speed of 300rpm for 20min to obtain a mixed material. The mixed material was melt-extruded by a twin-screw extruder with an aspect ratio of 42, water-cooled, pelletized, and dried to obtain nylon 12 composite pellets. The screw speed was 150rpm, and the temperature from the feeding section to the die was set to 180-220°C.

[0068] [Example 5]

[0069] The nylon 12 composition was prepared as follows:

[0070] 5kg nylon 12 (Wanhua Chemical, L2000, relative viscosity 1.90), 250g APY-PA-5, 15g lubricant EBS (Kao, Japan), and 15g antioxidant PEPQ (Clariant) were added to a high-speed mixer and mixed at a speed of 300rpm for 20min to obtain a mixed material. The mixed material was melt-extruded by a twin-screw extruder with an aspect ratio of 42, water-cooled, pelletized, and dried to obtain nylon 12 composite pellets. The screw speed was 150rpm, and the temperature from the feeding section to the die was set to 180-220°C.

[0071] [Comparative Example 1]

[0072] A nylon 12 composition was prepared in substantially the same manner as in Example 1, except that APY-PA-1 was not added.

[0073] [Comparative Example 2]

[0074] A nylon 12 composition was prepared in substantially the same manner as in Example 1, except that APY-PA-1 was replaced with an equal amount of APY-PA-6.

[0075] [Comparative Example 3]

[0076] 2kg of laurolactam (Wanhua Chemical), 10g of sebacic acid (Shanghai Kaisai Chemical Co., Ltd.), 0.1g of phosphoric acid (Beijing Inokai Technology Co., Ltd.) and 100g of ultrapure water were added to the reactor, and the atmosphere was replaced with nitrogen five times. The reactor was heated to 280°C and maintained for 5h to complete the ring-opening reaction of laurolactam. After the ring-opening reaction was completed, the pressure was released to 10kPa, and the temperature was lowered to 230°C while the pressure was released. 20g of 5-sulfonicotinic acid was added and then vacuumed to -90kPa for reaction for 120min to complete the melt polycondensation to prepare 5-sulfonicotinic acid modified nylon 12 resin.

[0077] The nylon compositions prepared in each embodiment and comparative example were extruded and cast to prepare films with a thickness of 100 μm (casting process at 230° C.), wherein the films prepared from the nylon 12 compositions in embodiments 1-5, comparative examples 2 and 3 were directly subjected to the performance tests in Table 1 without any treatment; the film prepared from the nylon 12 composition in comparative example 1 was divided into two parts, one of which was directly subjected to the performance tests in Table 1 without any treatment, and the other was first treated with the commercially available phenol yellowing agent Innovadol AY (Guangdong Jusheng New Materials) (immersed in a 50° C. Innovadol AY aqueous solution for 25 minutes, then dehydrated and dried), and then subjected to the performance tests in Table 1, recorded as comparative example 1-1. In addition, the mechanical property test results of the nylon 12 compositions in each embodiment and comparative example are also shown in Table 1.

[0078] Table 1. Performance test results

[0079]

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A nylon 12 composition resistant to phenolic yellowing, characterized in that: It includes the following components in parts by weight: 100 parts of nylon 12 resin, 2-10 parts of multi-arm nylon 12 phenol yellowing agent, Lubricant 0.1-0.5 parts, Antioxidant 0.1-0.5 parts; The multi-arm nylon 12 phenol yellowing resistance agent is prepared by reacting carboxyl-terminated multi-arm nylon 12 oligomers with aminosulfonic acid compounds.

2. The phenol yellowing-resistant nylon 12 composition according to claim 1, characterized in that: The number average molecular weight of the carboxyl-terminated multi-arm nylon 12 oligomer is 1500-8000; Preferably, the carboxyl-terminated multi-arm nylon 12 oligomer is prepared by reacting a dicarboxyl-terminated nylon 12 oligomer and a polyamine branching agent; the dicarboxyl-terminated nylon 12 oligomer preferably has a number average molecular weight of 500-2000; the polyamine branching agent is preferably one or more of benzene-1,2,3-triamine, 1,2,4,5-benzenetetramine, pentaminebenzene, and benzene-1,2,3,4,5,6-hexamine; Preferably, the added amounts of the dicarboxyl-terminated nylon 12 oligomer and the polyamine branching agent are 2:(0.9-1.1) in terms of the molar ratio of carboxyl group to amine group.

3. The phenol yellowing-resistant nylon 12 composition according to claim 2, characterized in that: The dicarboxyl-terminated nylon 12 oligomer is prepared by melt polycondensation of laurolactam and a dibasic acid-type end-capping agent in the presence of a catalyst; Preferably, the dibasic acid capping agent is selected from one or more of adipic acid, sebacic acid, and dodecanedioic acid; Preferably, the catalyst is at least one of phosphoric acid, hypophosphorous acid and sodium hypophosphite, and the added amount thereof is preferably 0.005-0.02% of the weight of the dicarboxyl-terminated nylon 12 oligomer.

4. The phenol yellowing-resistant nylon 12 composition according to any one of claims 1 to 3, characterized in that: The aminosulfonic acid compound is selected from one or more of aminosulfonic acid, aminomethanesulfonic acid, p-aminobenzenesulfonic acid, 4-aminotoluene-3-sulfonic acid, 2-aminobenzenesulfonic acid, and 3-aminopropanesulfonic acid; Preferably, the added amounts of the carboxyl-terminated multi-arm nylon 12 oligomer and the aminosulfonic acid compound are 1:(0.9-1.1) in terms of the molar ratio of the carboxyl group to the amine group.

5. The phenol yellowing-resistant nylon 12 composition according to any one of claims 1 to 4, characterized in that: The relative viscosity of the nylon 12 resin is 1.50-2.50, preferably 1.60-2.

20.

6. The phenol yellowing-resistant nylon 12 composition according to any one of claims 1 to 5, characterized in that: The lubricant is selected from one of ethylene bis stearamide (EBS), oleamide, silicone oil and paraffin.

7. The phenol yellowing-resistant nylon 12 composition according to any one of claims 1 to 6, characterized in that: The antioxidant is a compound without phenolic hydroxyl group, preferably one or more of the antioxidant SEED, antioxidant TFB-117, antioxidant 168, and antioxidant PEPQ.

8. A method for preparing a nylon 12 composition resistant to phenolic yellowing as claimed in any one of claims 1 to 7, characterized in that: The method comprises the process of mixing nylon 12 resin, multi-arm nylon 12 phenol yellowing resistance agent, lubricant and antioxidant at high speed and extruding, wherein the stirring speed of the high-speed mixing is 50-500 rpm, the mixing time is 10-30 minutes, the extrusion temperature is 180-280°C, and the screw speed is 100-500 rpm.

9. Use of the phenol yellowing-resistant nylon 12 composition according to any one of claims 1 to 7 in textile products.

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