Hydrolysis resistant agent, method of making, hydrolysis resistant glass fiber reinforced polybutylene terephthalate resin and method of making

Abstract

This invention discloses a hydrolysis-resistant agent and its preparation method. The hydrolysis-resistant agent is prepared by mixing a RAFT reagent containing macromolecular groups with a vinyl epoxy compound, an initiator, and an organic solvent, and reacting the mixture in a protective gas environment. When used as a hydrolysis-resistant agent for modifying polybutylene terephthalate (PBT) resin, it significantly improves the migration of the hydrolysis-resistant agent within the material matrix while maintaining its hydrolysis resistance. This invention also provides a hydrolysis-resistant glass fiber reinforced PBT resin material. Using the aforementioned hydrolysis-resistant agent, the hydrolysis problem during processing can be solved, allowing for a simple and efficient production of low-cost modified PBT materials that maintain performance, with broad application prospects in the automotive, home appliance, and electronics industries.

Description

Technical Field

[0001] This invention relates to the field of modified thermoplastic resin materials, and more specifically to a hydrolysis-resistant agent, a preparation method thereof, and a hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin material and its preparation method. Background Technology

[0002] Polybutylene terephthalate (PBT) resin has demonstrated its superior performance in certain industrial applications, making it the fifth most widely used engineering plastic after PA, PC, POM (polyoxymethylene), and MPPO (modified polyphenylene oxide).

[0003] PBT is a milky white, translucent to opaque, semi-crystalline thermoplastic polyester with high heat resistance and organic solvent resistance. However, due to its poor resistance to strong acids and alkalis, flammability, and decomposition at high temperatures, pure PBT resin often cannot meet the special application requirements of some fields. Moreover, simply improving the processing cannot solve this problem. Therefore, most PBT resin is processed into compound materials. After modification with various additives and blending with other resins, it can obtain good comprehensive properties such as heat resistance, flame retardancy, and electrical insulation, as well as good processing performance. It is widely used in industrial environments such as electrical appliances, automobiles, aircraft manufacturing, communications, home appliances, and transportation.

[0004] However, PBT resin materials modified by the above methods will also encounter various problems in actual processing; among them, material hydrolysis is the most common and troublesome aspect. Because PBT resin contains ester chains, it has a strong tendency to absorb moisture, with a water absorption rate of generally 0.2-0.3%. When processed in a hygroscopic state, the material chain segments are heated, and the ester chains will hydrolyze, thereby degrading the material.

[0005] Currently, the mainstream solutions in the market are mainly divided into two types: (1) Drying is required before processing to make the moisture content below 0.02%, the drying temperature is 110-130℃, and the time is about 4 hours. This method has a good effect on improving the performance of the final modified PBT material, but its operation is convenient and its timeliness is poor, which is not suitable for large production line factories; (2) During the processing of PBT material, hydrolysis resistant agent is added for physical blending. For this method, the type of hydrolysant has a greater impact on the final modified PBT material. Monomer carbodiimide, isocyanate, oxazoline compounds, epoxy and other materials have a low density of reactive groups and are poor in improving the hydrolysis effect. Increasing their quantity will have the risk of precipitation; while polymeric compounds can improve this phenomenon, but at present there are few material types to choose from, and they are basically all polymeric carbodiimide compounds, which will greatly increase the material cost.

[0006] Therefore, how to reduce material costs and enrich the variety of additives while ensuring the performance and processing efficiency of PBT materials is a challenging direction, but also a direction that can greatly expand the application fields of modified PBT materials. Summary of the Invention

[0007] In view of this, one of the objectives of this invention is to provide a hydrolysis-resistant agent and its preparation method. The hydrolysis-resistant agent is an epoxy monomer polymer with macromolecular end groups. This invention employs the RAFT polymerization method, selecting RAFT reagents with macromolecular end groups to directionally design the polymer, ultimately obtaining a polyepoxy hydrolysis-resistant agent material with macromolecular end groups. This hydrolysis-resistant agent can be applied in the field of modified PBT resin.

[0008] The second objective of this invention is to provide a hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin and its preparation method. By using the above-mentioned hydrolysis-resistant polyepoxy agent with macromolecular end groups, the hydrolysis problem during processing can be solved, and a low-cost modified PBT material that maintains its performance can be obtained simply and efficiently.

[0009] To achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0010] In a first aspect, the present invention provides a method for preparing a hydrolysis-resistant agent, comprising the following steps:

[0011] The RAFT reagent containing macromolecular groups is mixed with a vinyl epoxy compound, an initiator, and an organic solvent, and reacted in a protective gas environment to obtain the hydrolysis-resistant agent.

[0012] In one embodiment, the RAFT reagent containing macromolecular groups of the present invention, wherein the RAFT reagent is a reversible addition-fragmentation chain transfer reagent, has a branched chain structure, includes thioester compounds, wherein the macromolecular groups contained therein are one or more groups derived from dithioesters, dithiocarbamates, xanthates, and trithiocarbonates, preferably groups derived from dithioesters.

[0013] Preferably, the RAFT reagent containing macromolecular groups is one or more of benzyl dithiobenzoate, butyl dithiobenzoate, and isobutyl dithiobenzoate.

[0014] In one embodiment, the vinyl epoxy compound of the present invention is selected from one or more of vinyl ethylene oxide, vinyl ethylene oxide, vinyl ethylene oxide, etc., preferably one or more of vinyl ethylene oxide and vinyl ethylene oxide.

[0015] In one embodiment, the organic solvent of the present invention is selected from one or more of furans, alcohols, and haloalkanes, preferably one or more of tetrahydrofuran (THF), methanol, ethanol, and dichloromethane, and more preferably one or more of THF and ethanol.

[0016] In one embodiment, the initiator of the present invention is selected from azo compounds, preferably azobisisobutyronitrile (AIBN), azobisisovalerate (AMBN), azobisisoheptanenitrile (ABVN), and azobiscyclohexylformonitrile (ACCN), and more preferably one or more of AIBN and ABVN.

[0017] In one embodiment, the mass ratio of the RAFT reagent containing macromolecular groups to the vinyl epoxy compound of the present invention is 1:0.1-1000, and can be 1:0.1, 1:5, 1:10, 1:30, 1:50, 1:70, 1:90, 1:100, 1:120, 1:140, 1:160, 1:180, 1:200, 1:220, 1:240, 1:260, 1:280, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:700, 1:800, 1:900, 1:1000, or a range consisting of any two of these.

[0018] The mass ratio of the initiator to the vinyl epoxy compound is 1:10-1000, and can be 1:10, 1:50, 1:100, 1:150, 1:200, 1:250, 1:300, 1:350, 1:400, 1:450, 1:500, 1:550, 1:600, 1:650, 1:700, 1:750, 1:800, 1:850, 1:900, 1:950, 1:1000, or a range consisting of any two of these.

[0019] The amount of organic solvent used is 1 to 100 times the mass of the vinyl epoxy compound, and can be 1, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100 times, or any combination thereof.

[0020] In one embodiment, the reaction of the present invention is carried out at a temperature of 70-100°C for a time of 24-120 hours. Specifically, the temperature can be 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, or a range thereof, and the time can be 24 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, 65 hours, 70 hours, 75 hours, 80 hours, 85 hours, 90 hours, 100 hours, 110 hours, 120 hours, or a range thereof.

[0021] The reaction is carried out in a protective gas environment. In this invention, the protective gas refers to a gas that is inert in the reaction, such as nitrogen or argon.

[0022] Under normal circumstances, the reaction is carried out under stirring. The stirring speed can be selected according to actual needs, such as 200-800 rpm / min.

[0023] In one embodiment, after the reaction is completed, the present invention further includes allowing the reaction solution to stand for precipitation treatment, then filtering to obtain the precipitate, and drying to obtain the hydrolysis resistant agent.

[0024] The precipitation treatment has no special temperature requirements; for example, it can be carried out at room temperature. The precipitation time is 12-72 hours, which can be 12 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, 65 hours, 70 hours, 72 hours, or any range between two of these.

[0025] The drying process is vacuum drying, with a drying temperature of 70-100℃ and a drying time of 12-72 hours. Specifically, the drying temperature can be 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, or any combination thereof, and the drying time can be 12 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours, 50 hours, 55 hours, 60 hours, 65 hours, 70 hours, 72 hours, or any combination thereof.

[0026] Secondly, the present invention provides a hydrolysis-resistant agent prepared by the above method.

[0027] Specifically, the hydrolysis resistant agent is an epoxy monomer polymer with macromolecular groups at the end groups, with a molecular weight of 10,000-100,000, which can be 10,000, 20,000, 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, 100,000, or any combination thereof.

[0028] Thirdly, the present invention provides an application of the hydrolysis-resistant agent described above.

[0029] The hydrolysis-resistant agent described in this invention has advantages such as low cost and resistance to precipitation, and can be used in the processing of thermoplastic modified plastics, especially suitable for the preparation of modified PBT, TPU, PLA, etc.

[0030] Fourthly, the present invention provides a hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin, comprising the hydrolysis-resistant agent described above, specifically prepared from components comprising the following mass percentages:

[0031] Polybutylene terephthalate resin 35-90%,

[0032] 10-50% glass fiber

[0033] Toughening agent 3-20%,

[0034] Lubricant 0.1-1%,

[0035] Antioxidant 0.1-2%,

[0036] Hydrolysis resistant agent 0.1-5%,

[0037] Masterbatch 1-5%.

[0038] Specifically, the glass fiber reinforced polybutylene terephthalate resin is prepared from components comprising the following components in the indicated weight percentages:

[0039] The polybutylene terephthalate resin may be 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or a range thereof;

[0040] The glass fiber can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or a range of any two thereof;

[0041] The toughening agent may be 3%, 5%, 7%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, or a range thereof;

[0042] The lubricant may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or a range thereof;

[0043] The antioxidant may be 0.1%, 0.3%, 0.5%, 0.7%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, or a range thereof;

[0044] The hydrolysis-resistant agent may be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range thereof;

[0045] The color masterbatch can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range of any two of these.

[0046] In one embodiment, the polybutylene terephthalate resin has a melt flow index of 5-60 g / min at 250°C and 2.16 kg, which can be 5 g / min, 10 g / min, 20 g / min, 30 g / min, 40 g / min, 50 g / min, 60 g / min or any combination thereof, specifically tested according to ISO 1133 standard.

[0047] In one embodiment, the glass fiber is alkali-free chopped glass fiber; preferably, the fiber diameter is 10-15 μm and the fiber length is 1-5 mm. Specifically, the fiber diameter can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm or any combination thereof, and the fiber length can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm or any combination thereof.

[0048] Preferably, the glass fiber is one or more of ECS13-4.5-T438H, ECS13-4.5-T438R, and TLD-CS-T436S.

[0049] In one embodiment, the hydrolysis-resistant agent is the hydrolysis-resistant agent described above in this invention, and may also include existing known hydrolysis-resistant agents, such as one or more of ADR4468 and S9000, with a blending ratio not exceeding 50 wt%.

[0050] The resin described in this invention also includes conventional additives in the fields of toughening agents, lubricants, antioxidants, light stabilizers, and color masterbatches in its raw materials. In some specific examples, the raw material selection described below can be used:

[0051] The toughening agent is selected from one or more of polyolefin elastomers, ethylene propylene diene monomer (EPDM) rubber, ethylene-acrylate, glycidyl methacrylate, etc., preferably one or more of random terpolymers of ethylene-acrylate and glycidyl methacrylate (such as AX8900, PTW).

[0052] The lubricant is one or more of pentaerythritol stearate (PETS), zinc stearate (ZNST), and polyethylene wax;

[0053] The antioxidant is one or more of SUNSHOW 1010, SUNSHOW168, SUNSHOW5585, etc.

[0054] The masterbatch is one or more of UN6269, XP6621A, 3600, etc.

[0055] Fifthly, the present invention also provides a method for preparing the hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin, which can be prepared using conventional modification methods in the art. The specific operation and parameters can be screened according to actual conditions, and the present invention has no special requirements.

[0056] Specifically, a method for preparing a hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin includes the following steps:

[0057] The raw materials, excluding glass fiber, are mixed and fed into the main feed port of a twin-screw extruder, while the glass fiber is fed into the side feed port. The mixture is then extruded and granulated to obtain hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin.

[0058] The twin-screw extruder has a temperature set at 220-245℃ and a screw speed of 200-500 rpm. Specifically, the temperature can be 220℃, 225℃, 230℃, 235℃, 240℃, 245℃, or a range thereof, and the screw speed can be 200 rpm, 300 rpm, 400 rpm, 500 rpm, or a range thereof.

[0059] In the extrusion granulation process, the cooling water temperature is 10-50℃, and the pelletizer speed is 10-100 rpm. Specifically, the temperature can be 10℃, 20℃, 30℃, 40℃, 50℃, or a range of any two thereof, and the screw speed can be 10 rpm, 30 rpm, 50 rpm, 70 rpm, 90 rpm, 100 rpm, or a range of any two thereof.

[0060] In the above method, the raw materials entering the main feed inlet are mixed with a high-speed mixer until they are evenly dispersed; and all raw materials do not require pre-processing and can be used directly while remaining dry.

[0061] Compared with the prior art, the advantages of the technical solution of the present invention are as follows:

[0062] This invention utilizes RAFT (Rapid Active Polymerization) to design epoxy monomer polymers with macromolecular end groups for use as hydrolysis-resistant agents. By leveraging the "anchoring effect" of the macromolecular end groups, the migration of the hydrolysis-resistant agent within the matrix resin is limited, overcoming its tendency to precipitate. Applying this to modify PBT materials can solve the hydrolysis problem during processing, resulting in a hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin material that is easy to process and has controllable costs. Detailed Implementation

[0063] The following embodiments will further illustrate the method provided by the present invention, but the present invention is not limited to the listed embodiments, and should also include any other known modifications within the scope of the claims of the present invention.

[0064] Unless otherwise specified, the reagents, materials and instruments used in the following examples are all conventional reagents, materials and instruments in the art, and can be obtained commercially. The reagents involved can also be synthesized by conventional methods in the art.

[0065] Example of preparation of hydrolysis resistant agent:

[0066] The main raw materials used in the preparation process are as follows:

[0067] THF: Shanghai Maclean Biochemical Technology Co., Ltd.

[0068] 2-Vinyl ethylene oxide monomer: Shanghai Jixiang Biotechnology Co., Ltd.;

[0069] 2-Vinylepoxybutane monomer: Shanghai Jixiang Biotechnology Co., Ltd.;

[0070] Macromolecular end-group RAFT reagents: benzyl dithiobenzoate, butyl dithiobenzoate, Hubei Jianchu Biopharmaceutical Co., Ltd.

[0071] Initiator monomer: AIBN: Aladdin.

[0072] Preparation Example 1 (Hydrolysis-resistant agent S-1):

[0073] 1000g of THF solvent was added to a round-bottom flask, followed by 4g of RAFT reagent benzyl dithiobenzoate. After stirring for 20 minutes until the RAFT reagent was completely dissolved, 1g of initiator monomer AIBN and 500g of 2-vinyl ethylene oxide monomer were added to initiate the reaction. Argon gas was continuously introduced during the reaction to remove oxygen. The reaction conditions were 70℃, stirring speed 250rpm / min, and reaction time 72h. The product was then allowed to stand for 72h to precipitate, and the precipitate was obtained by filtration. The precipitate was dried in a vacuum oven at 100℃ for 24h to finally obtain hydrolysis resistant agent S-1 with a molecular weight of approximately 19267.

[0074] Preparation Example 2 (Hydrolysis-resistant agent S-2):

[0075] 10,000 g of ethanol solvent was added to a round-bottom flask, followed by 4 g of RAFT reagent butyl dithiobenzoate. After stirring for 20 min, the RAFT reagent was completely dissolved. Then, 1 g of initiator monomer ABVN and 1000 g of 2-vinylepoxybutane monomer were added to initiate the reaction. Nitrogen gas was continuously purged during the reaction to remove oxygen. The reaction conditions were 70 °C, stirring speed of 8000 rpm / min, and reaction time of 36 h. The product was then allowed to stand for 72 h to precipitate, and the precipitate was obtained by filtration. The precipitate was dried in a vacuum oven at 100 °C for 24 h to finally obtain hydrolysis resistant agent S-2 with a molecular weight of approximately 37568.

[0076] Preparation Example 3 (Hydrolysis-resistant agent S-3):

[0077] 10,000 g of THF solvent was added to a round-bottom flask, followed by 10 g of RAFT reagent benzyl dithiobenzoate. After stirring for 20 min, the RAFT reagent was completely dissolved. Then, 1 g of initiator monomer ABVN and 100 g of 2-vinyl ethylene oxide monomer were added to initiate the reaction. Nitrogen gas was continuously purged during the reaction to remove oxygen. The reaction conditions were 90 °C, stirring speed 200 rpm / min, and reaction time 24 h. The product was then allowed to stand for 72 h to precipitate, and the precipitate was obtained by filtration. The precipitate was dried in a vacuum oven at 100 °C for 24 h to finally obtain hydrolysis resistant agent S-3 with a molecular weight of approximately 10798.

[0078] The following are examples of the use of the above-mentioned hydrolysis-resistant agent in the preparation of hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin.

[0079] Example 1

[0080] The main raw materials used in the preparation process of this embodiment and their source information are as follows:

[0081] Polybutylene terephthalate resin 1100-211S has a melt flow index of 12 g / min, and the test conditions are in accordance with ISO 1133 standard: 250℃, 2.16Kg; produced by Changchun Chemical (Jiangsu) Co., Ltd.

[0082] The glass fiber is ECS13-4.5-T438H, produced by Taishan Fiberglass, with a fiber diameter of 13um and a fiber length of 4.5mm;

[0083] The toughening agent is a random terpolymer of glycidyl methacrylate, brand name PTW, manufactured by DuPont.

[0084] The lubricant is zinc stearate (ZnST), manufactured by Faji Co., Ltd.

[0085] The antioxidants are SUNSHOW 168 and SUNSHOW1010, manufactured by New Star Chemical Co., Ltd.

[0086] The masterbatch is XP6621A, manufactured by Capote Inc.

[0087] The hydrolysis-resistant agent is the hydrolysis-resistant agent S-1 of Preparation Example 1 above.

[0088] Weigh each raw material (wt%) according to the formula in Table 1 below. Add all raw materials except glass fiber to a high-speed mixing pot. After 5 minutes of high-speed mixing, feed the mixture into a twin-screw extruder through the main feed inlet. Feed the glass fiber raw material into the side feed inlet. Finally, extrude and granulate using a twin-screw extruder to obtain the final product. The extrusion process is as follows: Zone 1: 235℃, Zone 2: 235℃, Zone 3: 240℃, Zone 4: 240℃, Zone 5: 240℃, Zone 6: 240℃, Zone 7: 240℃, Zone 8: 240℃, Zone 9: 240℃, Zone 10: 230℃; Extruder screw speed: 250 rpm; Cooling water temperature: 20℃; Pelletizer speed: 100 rpm.

[0089] Example 2

[0090] The main raw materials used in the preparation process of this embodiment and their source information are as follows:

[0091] Polybutylene terephthalate resin 1100-211M has a melt flow index of 30 g / min, and the test conditions are in accordance with ISO 1133 standard: 250℃, 2.16Kg; produced by Changchun Chemical (Jiangsu) Co., Ltd.

[0092] The toughening agent is a random terpolymer of glycidyl methacrylate, brand name AX8900, manufactured by Arkema.

[0093] The glass fiber is ECS13-4.5-T438R, produced by Taishan Fiberglass, with a fiber diameter of 13um and a fiber length of 4.5mm;

[0094] The lubricant is zinc stearate (ZnST), manufactured by Faji Co., Ltd.

[0095] The antioxidants are SUNSHOW 168 and SUNSHOW1010, manufactured by New Star Chemical Co., Ltd.

[0096] The masterbatch is UN6269, manufactured by Capote Inc.

[0097] The hydrolysis-resistant agent is the hydrolysis-resistant agent S-2 of Preparation Example 1 above.

[0098] Weigh each raw material (wt%) according to the formula in Table 1 below. Add all raw materials except glass fiber to a high-speed mixing pot and mix at high speed for 5 minutes. Then, feed the mixture into a twin-screw extruder through the main feed port. Feed the glass fiber raw material into the side feed port. Finally, extrude and granulate using a twin-screw extruder to obtain the final product. The extrusion process is as follows: Zone 1: 235℃, Zone 2: 235℃, Zone 3: 240℃, Zone 4: 240℃, Zone 5: 240℃, Zone 6: 240℃, Zone 7: 240℃, Zone 8: 240℃, Zone 9: 240℃, Zone 10: 230℃; Extruder screw speed: 400 rpm; Cooling water temperature: 30℃; Pelletizer speed: 20 rpm.

[0099] Example 3 (Hydrolysis-resistant agent S-3):

[0100] The hydrolysis-resistant agent used in the preparation process of this embodiment is the hydrolysis-resistant agent S-3 of Preparation Example 1 above. The selection and source information of other main raw materials are the same as those in Example 1.

[0101] Weigh each raw material (wt%) according to the formula in Table 1 below. Add all raw materials except glass fiber to a high-speed mixing pot. After 5 minutes of high-speed mixing, feed the mixture into a twin-screw extruder through the main feed inlet. Feed the glass fiber raw material into the side feed inlet. Finally, extrude and granulate using a twin-screw extruder to obtain the final product. The extrusion process is as follows: Zone 1: 220℃, Zone 2: 230℃, Zone 3: 240℃, Zone 4: 240℃, Zone 5: 240℃, Zone 6: 240℃, Zone 7: 245℃, Zone 8: 240℃, Zone 9: 240℃, Zone 10: 230℃; Extruder screw speed: 300 rpm; Cooling water temperature: 50℃; Pelletizer speed: 50 rpm.

[0102] Comparative Example 1-1:

[0103] The modified PBT was prepared by following the method of Example 1, except that hydrolysis resistant agent S-1 was not added to the raw materials, while other operations and conditions remained unchanged.

[0104] Comparative Examples 1-2:

[0105] The modified PBT was prepared by following the method of Example 1, except that the hydrolysis resistant agent S-1 in the raw materials was replaced with the hydrolysis resistant agent S9000 (Shanghai Langyi Co., Ltd.), while other operations and conditions remained unchanged.

[0106] Comparative Example 2-1:

[0107] The method of Example 2 is different in that: hydrolysis resistant agent S-2 is not added to the raw materials, and all raw materials are post-dried at 110°C for 4 hours before processing; other operations and conditions remain unchanged, and modified PBT is obtained.

[0108] Comparative Example 2-2:

[0109] The modified PBT was prepared by following the method of Example 2, except that the hydrolysis resistant agent S-2 in the raw materials was replaced with ADR4468 (BASF), while other operations and conditions remained unchanged.

[0110] Comparative Example 3-1:

[0111] The modified PBT was prepared by following the method of Example 3, except that hydrolysis resistant agent S-3 was not added to the raw materials, while other operations and conditions remained unchanged.

[0112] It includes a total of 8 groups: 3 case studies and 5 corresponding control groups.

[0113] Table 1. Raw material formulations for examples and comparative examples.

[0114]

[0115] The modified polybutylene terephthalate resin products prepared in the examples and comparative examples were tested for their properties using the following methods:

[0116] Melt flow index: ISO 1133;

[0117] Density: ISO 1183;

[0118] Tensile strength: ISO 527;

[0119] Bending strength: ISO 178;

[0120] Flexural modulus: ISO 178;

[0121] Unnotched impact test of simply supported beams: ISO 179;

[0122] Xenon lamp aging: Q / BYDQ-A1901.800.

[0123] Specifically, the hydrolysis resistance during processing is judged comprehensively based on the melt index and mechanical property data after modification: 1. The larger the melt index, the greater the degree of hydrolysis; 2. The worse the mechanical properties, the greater the degree of hydrolysis.

[0124] The mechanical properties of the embodiments and comparative examples are shown in Table 2:

[0125] Table 2 Performance of Examples and Comparative Examples

[0126]

[0127] As shown in Table 2, the melt index and mechanical properties data indicate that the macromolecular end-group hydrolysis-resistant agent prepared in this invention can effectively inhibit hydrolysis during PBT processing. While controlling costs, it maintains the material's performance well, achieving the same performance as commercially available hydrolysis-resistant agents (carbodiimide polymers). Xenon lamp aging results show that the macromolecular end-group hydrolysis-resistant agent prepared in this invention exhibits better xenon lamp aging resistance than conventional hydrolysis-resistant agents, and is superior to currently available materials on the market.

Claims

1. A method for preparing a hydrolysis-resistant agent, characterized in that, Includes the following steps: The RAFT reagent containing macromolecular groups is mixed with a vinyl epoxy compound, an initiator, and an organic solvent, and reacted in a protective gas environment to obtain the hydrolysis-resistant agent. The vinyl epoxy compound is selected from one or more of vinyl epoxymethane, vinyl epoxybutane, and vinyl epoxyethylene; The molecular weight of the hydrolysis-resistant agent is 10,000-100,000; The RAFT reagent containing macromolecular groups is one or more of benzyl dithiobenzoate, butyl dithiobenzoate, and isobutyl dithiobenzoate.

2. The preparation method according to claim 1, characterized in that, The organic solvent is selected from one or more of furans, alcohols, and haloalkane compounds; and / or The initiator is selected from azo compounds; and / or The mass ratio of the RAFT reagent containing macromolecular groups to the vinyl epoxy compound is 1:0.1-1000; and / or The mass ratio of the initiator to the vinyl epoxy compound is 1:10-1000; and / or The amount of organic solvent used is 1-100 times the mass of the vinyl epoxy compound.

3. The preparation method according to claim 2, characterized in that, The organic solvent is selected from one or more of tetrahydrofuran, methanol, ethanol, and dichloromethane; and / or The initiator is selected from one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, and azobiscyclohexylformitrile.

4. The preparation method according to claim 1, characterized in that, The reaction is carried out at a temperature of 70-100℃ for a time of 24-120 hours; and / or The protective gas refers to a gas that is inert in the reaction; and / or After the reaction is completed, the reaction solution is allowed to stand for precipitation treatment, then filtered to obtain the precipitate, and dried to obtain the hydrolysis resistant agent.

5. The preparation method according to claim 4, characterized in that, The protective gas is selected from nitrogen and argon.

6. The preparation method according to claim 4, characterized in that, The precipitation treatment takes place over a period of 12-72 hours.

7. The preparation method according to claim 4, characterized in that, The drying process is vacuum drying, with a drying temperature of 70-100℃ and a drying time of 12-72 hours.

8. A hydrolysis-resistant agent prepared by the method according to any one of claims 1-7.

9. The application of the hydrolysis-resistant agent according to claim 8, characterized in that, Used in the processing of thermoplastic plastics.

10. The application according to claim 9, characterized in that, It is suitable for preparing modified PBT, TPU, and PLA.

11. A hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin, characterized in that, The hydrolysis-resistant agent prepared by the method according to any one of claims 1-7 or the hydrolysis-resistant agent according to claim 8 is specifically prepared from components comprising the following mass percentages: Polybutylene terephthalate resin 35-90%, 10-50% glass fiber Toughening agent 3-20%, Lubricant 0.1-1%, Antioxidant 0.1-2%, Hydrolysis resistant agent 0.1-5%, Masterbatch 1-5%.

12. The glass fiber reinforced polybutylene terephthalate resin according to claim 11, characterized in that, The polybutylene terephthalate resin has a melt flow index of 5-60 g / min at 250°C and 2.16 kg; and / or The glass fiber is alkali-free chopped glass fiber; and / or The hydrolysis-resistant agent is a hydrolysis-resistant agent prepared by the method according to any one of claims 1-7 or the hydrolysis-resistant agent according to claim 8, optionally, it also includes existing known hydrolysis-resistant agents; and / or The toughening agent is selected from one or more of polyolefin elastomers, EPDM rubber, and ethylene-acrylate; and / or The lubricant is one or more of pentaerythritol stearate, zinc stearate, and polyethylene wax.

13. The glass fiber reinforced polybutylene terephthalate resin according to claim 12, characterized in that, The glass fiber has a diameter of 10-15 μm and a length of 1-5 mm.

14. The glass fiber reinforced polybutylene terephthalate resin according to claim 12, characterized in that, The glass fiber is one or more of ECS13-4.5-T438H, ECS13-4.5-T438R, and TLD-CS-T436S.

15. The glass fiber reinforced polybutylene terephthalate resin according to claim 12, characterized in that, The hydrolysis-resistant agent is blended with one or more of BASF ADR4468 and hydrolysis-resistant agent S9000, and the blending ratio does not exceed 50 wt%.

16. The glass fiber reinforced polybutylene terephthalate resin according to claim 12, characterized in that, The toughening agent is selected from one or more random terpolymers of ethylene-acrylate and glycidyl methacrylate.

17. A method for preparing the hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin according to any one of claims 11-16, characterized in that the step... include: The raw materials, excluding glass fiber, are mixed and fed into the main feed port of a twin-screw extruder, while the glass fiber is fed into the side feed port. The mixture is then extruded and granulated to obtain hydrolysis-resistant glass fiber reinforced polybutylene terephthalate resin.

18. The preparation method according to claim 17, characterized in that, The twin-screw extruder is set to a temperature of 220-245℃ and a screw speed of 200-500 rpm; and / or The extrusion granulation process involves cooling water at a temperature of 10-50℃ and a pelletizer speed of 10-100 rpm.

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