Low-precipitation high-transparency high-toughness polyamide material as well as preparation method and application thereof

Abstract

The invention provides a low-precipitation high-transparency high-toughness polyamide material as well as a preparation method and application thereof. The polyamide material comprises polyamide and a specific small molecule capturing agent. According to the low-precipitation, high-transparency and high-toughness polyamide material disclosed by the invention, residual monomers and oligomers of polyamide are reduced in the production process, so that the precipitation resistance problem is obviously improved, the high transparency of the material is maintained, the low-temperature toughness resistance is realized, and the application range in the fields of medium storage and transportation can be widened.

Description

Technical Field

[0001] This invention belongs to the field of polymer material synthesis and processing, specifically relating to a low-exudation, high-transparency, and high-toughness polyamide material, its preparation method, and its application. Background Technology

[0002] Nylon, as an engineering plastic, is widely used in the automotive and industrial fields. The use of nylon products often requires flexibility modification to reduce its inherent hardness and improve its processing performance. For example, plasticizers can be added to modify polyamides, reducing the tensile modulus of nylon and increasing its flexibility and impact toughness. Common plasticizers include Kunststoff-Handbuch, Band VIPolyamide, and suitable plasticizers disclosed in Section 3.4.2.1b) on pages 238 and 239 of Carl Hanser Verlag München (1966) and Table 7. These plasticizers are categorized into aromatic hydroxyl compounds, sulfonamides, lactams, lactones, and alcohols, and are currently widely used commercially. US2214405A discloses a flexible polyamide prepared by using N-butylbenzenesulfonamide as a plasticizer for nylon, but its low-temperature toughness is poor. CN112480661A discloses a high-temperature and hydrolysis-resistant modified polyamide pipe material, which uses N-butylbenzenesulfonamide as a toughening agent and adds SEBS-type toughening agents to improve the low-temperature toughness of the composition. However, the introduction of elastomers inevitably affects the transparency of the material itself, and the disclosed composition contains color masterbatch, making it difficult for light to pass through, thus further limiting the application of the material. EP0748847B1 discloses a polyamide resin composition that combines PA11 or PA12 with a specific plasticizer mixture and modified polyolefin, solving the problems of flexibility and low-temperature impact resistance in high-speed pipe molding. However, the transparency is reduced due to the addition of toughening agents. Meanwhile, the polymerization methods of common nylon materials are divided into ring-opening polymerization and polycondensation polymerization depending on the nylon monomer. After ring-opening polymerization, there are more small molecules and residues in the system than in polycondensation, thus limiting the use of the corresponding nylon products. CN119798979A discloses a liquid-type silicon-containing polymer liquid as a descaling agent, which removes small molecules during the production process. However, the descaling effect is generally poor and affects production capacity, and the transparency of the produced products still exists.

[0003] In view of this, for existing technical solutions, on the one hand, it is necessary to improve the flexibility of existing materials and enhance their low-temperature toughness while avoiding the reduction of light transmittance; on the other hand, it is necessary to focus on solving the precipitation of residual monomers in the materials, so as to avoid the precipitation of contaminating the medium during transportation. Summary of the Invention

[0004] To address the aforementioned technical problems, one objective of this invention is to provide a low-exudation, high-transparency, and high-toughness polyamide material. By adding a small-molecule scavenger, the polyamide monomer undergoes ring-opening during processing, resulting in small-molecule chain growth. Simultaneously, the small-molecule scavenger reacts with the polyamide matrix, increasing the molecular weight of the polyamide material and thus enhancing its toughness. The added small-molecule scavenger is a liquid, uniformly dispersed within the polyamide matrix, and does not affect the polyamide's light transmittance, allowing for real-time monitoring during subsequent storage and transport applications.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0006] A polyamide material, said material being prepared by comprising components in the following mass ratios:

[0007] 77–99.1 parts of polyamide;

[0008] 0.2–5 parts of small molecule scavenging agent;

[0009] The small molecule scavenger comprises the following general structural formula:

[0010]

[0011] Wherein, R is an initiator residue, comprising one or more of hydrogen atoms, C1-C12 alkyl groups, and 2,3-dihydroxypropoxy, trimethylolpropane, or pentaerythritol-derived residues; R1 comprises hydrogen atoms and / or methyl groups; a and b are both non-negative numbers ≤100 and not both 0, preferably a=0 and b≤90.

[0012] Due to the water absorption of nylon, the cyclic monomers will undergo ring-opening under the action of water. The inventors introduced a small molecule scavenger. Because the small molecule scavenger can form bonds with monomers, oligomers, etc., and "bind" them to the polyamide molecular chain, it restricts the movement of small molecules and realizes the precipitation of small molecules in the polyamide composition. At the same time, the small molecule scavenger reacts with the polyamide itself due to its own functional groups, thereby increasing the molecular weight of the polyamide material and also achieving the toughening effect of the polyamide material.

[0013] In one embodiment of the present invention, the polyamide is a ring-opening polymerization product, preferably a C6-C18 ring-opening polymerization product, and more preferably one or more of PA6, PA11, PA12, and PA13.

[0014] In one embodiment of the present invention, the polyamide has a water content of ≤2wt%.

[0015] In one embodiment of the present invention, the material is prepared by comprising a plasticizer and an additive in the following mass ratio:

[0016] Plasticizer 0.2-15 parts;

[0017] Additives: 0.5 to 3 parts.

[0018] In one embodiment of the present invention, the plasticizer is a hydroxybenzoic acid ester and / or an aromatic sulfonamide, preferably one or more of p-hydroxybenzoic acid, o-hydroxybenzoic acid, octyl p-hydroxybenzoate, p-benzenesulfonamide, N-butylbenzenesulfonamide, methyl p-hydroxybenzoate, and N-methylbenzenesulfonamide.

[0019] In one embodiment of the present invention, the additive is one or more of antioxidants, lubricants, and photoaging agents; preferably, the antioxidant comprises one or more of aromatic amines, sterically hindered phenols, phosphites, sulfur-containing synergists, hydroxylamine benzofuranone derivatives, and potassium iodide-copper iodide inorganic stabilizers; preferably, the lubricant comprises one or more of titanate, stearic acid, erucamide, oleamide, and silicone; preferably, the photoaging agent comprises an ultraviolet absorber and a light stabilizer, wherein the ultraviolet absorber preferably comprises one or more of benzoic acid derivatives, benzophenone derivatives, and benzotriazole, and the light stabilizer preferably comprises hindered amine stabilizers.

[0020] Another object of the present invention is to provide a method for preparing polyamide materials.

[0021] A method for preparing polyamide materials, wherein the method prepares the above-mentioned materials by extrusion granulation using a twin-screw extruder.

[0022] In this invention, the preferred extrusion temperature is 230–260°C, the screw speed is 500–700 rpm, the vacuum degree is -0.05–-0.07 MPa, and the length-to-diameter ratio of the twin-screw extruder is 35–44:1. The process described is a conventional preparation process for polyamide materials in this field.

[0023] Another object of the present invention is to provide an application of polyamide materials.

[0024] An application of a polyamide material, wherein the material is the polyamide material described above, or a polyamide material prepared by the method described above, wherein the polyamide material is applied in the field of low-exudation, high-transparency, and high-toughness polyamide materials, and is preferably used in the field of pipes and cables.

[0025] Compared with the prior art, the positive effects of the present invention are as follows:

[0026] (1) Add small molecule trapping agent to achieve bonding with small molecules in polyamide, inhibit the precipitation of small molecules, and avoid contaminating the fluid when polyamide material is used as a fluid.

[0027] (2) Small molecule scavengers can also react with the polyamide matrix itself in the processing state, thereby increasing the molecular weight of the polyamide material. This, combined with the synergistic effect of conventional plasticizers, improves the toughness of the material, especially the low-temperature toughness, and broadens the application range of the material.

[0028] (3) The small molecule scavenger is a liquid, unlike conventional toughening agents. It has good dispersibility in the system, maintains the light transmittance of the material, and can be monitored in real time during subsequent storage and transportation media applications. Detailed Implementation

[0029] To facilitate understanding of the present invention, the following description, in conjunction with embodiments, will further illustrate the invention. It should be understood that the following embodiments are merely for a better understanding of the invention and do not imply that the invention is limited to these embodiments.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The term "and / or" may be used herein to include any and all combinations of one or more of the associated listed items.

[0031] Main raw material sources:

[0032] The sources of raw materials are shown in Table 1:

[0033] Table 1 Source of Raw Materials

[0034] Raw material grade Types of materials supplier Wanamid L3000 Polyamide 12 Wanhua Chemical Group Co., Ltd. M2800 Polyamide 6 Xinhui Meida BMVO Polyamide 11 Arkema Butylbenzenesulfonamide plasticizer Jinzhong Chemical AMT-403 Small molecule trap Yantai Kaisheng Chemical M600 Small molecule trap Huntsman Group Limited M2070 Small molecule trap Nanjing Chenhui Trading Co., Ltd. AMT-5000 Small molecule trap Yantai Kaisheng Chemical 1098 antioxidants BASF Corporation 168 antioxidants BASF Corporation Calcium stearate lubricant Liyang Chemical UV234 UV absorber BASF Corporation Light stabilizer 944 Light stabilizers BASF Corporation OFX-8803 Liquid descaling agent Dow Corning Inc.

[0035] Of the above raw materials:

[0036] M600: Structural formula H3C-O-CH2CH2-[O-CH2CH(CH3)]9-NH2, R is methyl, R1 is methyl, a is 1, b is 9;

[0037] T403: Structural formula C2H5C(CH2(OCH2CH(CH3)) b -NH2)3, R is trimethylolpropane, R1 is methyl, a is 0, b≤6;

[0038] M2070: Structural formula CH3-(O-CH2CH2)6-(O-CH(CH3)-CH2) 35 -NH2, R is methyl, R1 is methyl, a is 6, b is 35;

[0039] AMT5000: Structural formula CH3-(O-CH2-CH(CH3)) 29 -NH2, R is 2,3-dihydroxypropoxy (glycerol-derived residue), R1 is methyl, a is 0, b≤85.

[0040] Main testing methods:

[0041] Notched impact strength of simply supported beam: tested at -30℃ according to ISO179A standard, model: INSTRON-9050;

[0042] Light transmittance and haze: According to GB / T 2410, sheet material, 2mm thickness; model: Xrite-7860.

[0043] Extraction Test: Prepare an 8*1mm pipe (outer diameter 8mm, wall thickness 1mm) from the polyamide composition. Take a 1.0–1.5m section, denoted as L. Before the experiment, flush the inside of the pipe at least twice with FAMB oil. Then fill the inside of the pipe with FAMB, seal both ends with clean metal plugs, and place the pipe at 60℃ for 96 hours. Remove and cool the pipe, pour the fuel liquid into a clean beaker, and flush the inside of the pipe with fresh test solution. Pour the flushing solution into the same container. In a beaker, cover it with a lid or aluminum foil and place it at an ambient temperature of 23°C for 24 hours. Then, filter the test solution through a pre-weighed filter membrane (accurate to 0.1 mg) using a filtration device. The filtration is performed under vacuum. The filter membrane is dried to constant weight (drying for 8 hours in an explosion-proof convection oven set at 40°C). The weight of the precipitate is obtained by calculating the weight difference before and after filtration (drying). The calculated weight is related to the inner surface area of ​​the pipe. The inner surface area is calculated as S = π * d * L.

[0044] Weigh the raw materials according to the components and proportions (number of parts) in Table 1, with the weight of the example and comparative examples being 10 kg. Mix them in a high-speed mixer for 5 minutes to ensure uniform mixing. Add the liquid raw materials through a liquid weigher. Extrude and granulate the mixed blend through a twin-screw extruder.

[0045] Preparation process: The twin-screw extruder has a screw diameter of 28 mm, an extrusion screw length-to-diameter ratio of 40, an extrusion speed of 700 rpm / min, and temperatures in zones 2-10 of 200℃ / 230℃ / 240℃ / 240℃ / 240℃ / 240℃ / 240℃, respectively, with a vacuum reading of -0.06 MPa; polyamide compositions were obtained, and the products were labeled as PA1# to PA8#.

[0046] Table 2. Components and dosage (kg) of polyamide composition (A)

[0047]

[0048] Table 3 Properties of Polyamide Compositions

[0049]

[0050]

[0051] Based on the data in Tables 2 and 3, the only difference between Example 1 and Comparative Example 1, and between Example 2 and Comparative Examples 2 and 3, is the content of small molecule scavengers in the composition. After adding small molecule scavengers, the low-temperature impact performance of the material is significantly improved. However, when the small molecule scavengers exceed the upper and lower limits of the present invention, the improvement in toughness and light transmittance performance is insufficient.

[0052] Compared with Comparative Example 4, Example 3 differs only in the structure of small molecule amines. The trapping agent used in this invention is superior to other small molecules with amine functional groups in terms of light transmittance, low-temperature toughness, and the performance of precipitates.

[0053] It is readily understood that the above embodiments are merely illustrative examples for clear explanation and do not imply that the invention is limited thereto. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A polyamide material, characterized in that, The material is prepared by comprising components in the following mass ratios: 77–99.1 parts of polyamide; Small molecule scavenging agent 0.2–5 parts; The small molecule scavenger comprises the following general structural formula: Wherein, R is an initiator residue, comprising one or more of hydrogen atoms, C1-C12 alkyl groups, and 2,3-dihydroxypropoxy, trimethylolpropane, or pentaerythritol-derived residues; R1 comprises hydrogen atoms and / or methyl groups; a and b are both non-negative numbers ≤100 and not both 0, preferably a=0 and b≤90.

2. The material according to claim 1, characterized in that, The polyamide is a ring-opening polymerization product, preferably a C6-C18 ring-opening polymerization product, and more preferably one or more of PA6, PA11, PA12, and PA13; And / or, the polyamide has a moisture content ≤2wt%.

3. The material according to claim 1 or 2, characterized in that, The material is prepared by comprising plasticizers and additives in the following mass ratios: Plasticizer 0.2-15 parts; Additives: 0.5 to 3 parts.

4. The material according to any one of claims 1-3, characterized in that, The plasticizer is a hydroxybenzoate and / or an aromatic sulfonamide, preferably one or more of p-hydroxybenzoic acid, o-hydroxybenzoic acid, octyl p-hydroxybenzoate, p-benzenesulfonamide, N-butylbenzenesulfonamide, methyl p-hydroxybenzoate, and N-methylbenzenesulfonamide.

5. The material according to any one of claims 1-4, characterized in that, The additive is one or more of antioxidants, lubricants, and photoaging agents; Preferably, the antioxidant comprises one or more of the following: aromatic amines, sterically hindered phenols, phosphites, sulfur-containing synergists, hydroxylamine benzofuranone derivatives, and potassium iodide-copper iodide inorganic stabilizers. Preferably, the lubricant comprises one or more of titanate, stearic acid, erucamide, oleamide, and silicone; Preferably, the photoaging agent comprises an ultraviolet absorber and a light stabilizer, wherein the ultraviolet absorber preferably comprises one or more of benzoic acid, benzophenone derivatives, and benzotriazole, and the light stabilizer preferably comprises a hindered amine stabilizer.

6. A method for preparing a polyamide material, wherein the method prepares the material according to any one of claims 1-5, characterized in that, The method uses a twin-screw extruder to granulate and prepare polyamide materials.

7. An application of a polyamide material, wherein the material is the polyamide material according to any one of claims 1-5, or the polyamide material prepared by the method of claim 6, wherein the polyamide material is applied in the field of low-exudation, high-transparency, and high-toughness polyamide materials, preferably in the field of pipes and cables.

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