Polyamide composite material as well as preparation method and application thereof

Abstract

The invention provides a polyamide composite material as well as a preparation method and application thereof, and the polyamide composite material comprises the following components in parts by weight: 33-95 parts of polyamide resin, 6-18 parts of a nitrogen flame retardant, 5-15 parts of polyethylene glycol, 0.5-3 parts of an isocyanurate compound containing carbon-carbon double bonds and 0.5-3 parts of a phosphite compound. According to the polyamide composite material disclosed by the invention, the problems of low tracking resistance index and poor impact resistance of a nitrogen-based flame-retardant polyamide composite material in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a polyamide composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Polyamide, commonly known as nylon, is an important thermoplastic engineering plastic. Due to its many excellent properties such as high strength, good self-lubricity, wear resistance, oil resistance, and easy molding and processing, it is widely used in fields such as automobiles, mechanical parts, electronic and electrical appliances, household appliances, and new energy. To improve the flame retardancy of polyamide, flame retardants are usually added, such as nitrogen-based flame retardants, phosphorus-based flame retardants, etc.; among them, nitrogen-based flame-retarded polyamide is often used in industries such as connectors, low-voltage electrical appliances, and energy storage due to its excellent comprehensive mechanical properties, easy coloring, easy processing, and high comparative tracking index (CTI). However, the comparative tracking index (IPT) of nitrogen-based flame-retarded polyamide is low, and it is difficult to be applied in fields such as automobiles, electronic and electrical appliances; moreover, usually to improve the IPT of polyamide materials, the mechanical properties of polyamide materials will be lost, such as a decrease in impact strength.

[0003] Therefore, developing a nitrogen-based flame-retarded polyamide composite material with high IPT and good impact resistance is an urgent problem to be solved in this field. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a polyamide composite material, a preparation method thereof, and an application thereof. The polyamide composite material solves the problems of low comparative tracking index and poor impact resistance of nitrogen-based flame-retarded polyamide composite materials in the existing technology.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a polyamide composite material. Calculated by weight, the polyamide composite material comprises 33-95 parts of polyamide resin, 6-18 parts of nitrogen-based flame retardant, 5-15 parts of polyethylene glycol, 0.5-3 parts of isocyanuric acid ester compounds containing carbon-carbon double bonds, and 0.5-3 parts of phosphite compounds.

[0007] In the present invention, through the compounding of polyethylene glycol, isocyanuric acid ester compounds containing carbon-carbon double bonds, and phosphite compounds, and controlling the content of each component within a specific range, not only can the comparative tracking index of the polyamide composite material be improved, but also the polyamide composite material can be ensured to have good impact resistance.

[0008] In the present invention, the weight of the polyamide resin is preferably 34-93 parts, more preferably 51-91 parts, and particularly preferably 74-90 parts.

[0009] In the present invention, the weight of the nitrogen-based flame retardant is preferably 6.8 to 16.6 parts, more preferably 7.7 to 13.7 parts.

[0010] In the present invention, the weight of the polyethylene glycol is preferably 7.2 to 13.2 parts.

[0011] In the present invention, the mass percentage content of polyethylene glycol in the polyamide composite material is 4 to 14%, more preferably 7 to 12%.

[0012] In the present invention, the weight of the isocyanurate compound containing a carbon-carbon double bond is preferably 0.82 to 1.85 parts.

[0013] In the present invention, the weight of the phosphite compound is preferably 1.1 to 1.9 parts.

[0014] Preferably, the polyamide resin includes at least one of a condensation product of a dicarboxylic acid and a diamine, a condensation product of an aminocarboxylic acid, or a ring-opening polymerization product of an intralactam.

[0015] In the present invention, the dicarboxylic acid includes at least one of an aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid, or an aromatic dicarboxylic acid; the aliphatic dicarboxylic acid includes C4-C20 dicarboxylic acids, exemplarily including but not limited to succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, tetradecanedioic acid, octadecanedioic acid, etc.; the alicyclic dicarboxylic acid includes 1,4-cyclohexanedicarboxylic acid; the aromatic dicarboxylic acid includes terephthalic acid, isophthalic acid, phthalic acid, furandicarboxylic acid, etc.; the dicarboxylic acid can be used alone or at least two of them can be used in combination to form a condensation product with a diamine.

[0016] In the present invention, the diamine includes at least one of an aliphatic diamine and an aromatic diamine; the aliphatic diamine includes C4-C20 diamines, exemplarily including but not limited to butanediamine, pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, tetradecanediamine, octadecanediamine, etc.; the aromatic diamine includes p-phenylenediamine, m-phenylenediamine, etc.; the diamine can be used alone or at least two of them can be used in combination to form a condensation product with a dicarboxylic acid.

[0017] In the present invention, the aminocarboxylic acid can be used alone or at least two of them can be used in combination; the aminocarboxylic acid exemplarily includes iminodiacetic acid, etc.; the intralactam can be used alone or at least two of them can be used in combination, exemplarily including caprolactam.

[0018] Preferably, the polyamide resin includes polyhexamethylene adipamide and / or polycaprolactam.

[0019] Preferably, the relative viscosity of the polyamide resin is 2 to 3.4, more preferably 2.2 to 2.8.

[0020] In the present invention, the relative viscosity of the polyamide resin is the relative viscosity measured at 25 °C for a sulfuric acid solution of 0.01 g / mL polyamide resin.

[0021] The method for testing the relative viscosity includes: weighing 0.5 g of polyamide resin, transferring it to a 50 mL volumetric flask, adding about 40 mL of 96% by mass sulfuric acid, sonicating until the polyamide resin is completely dissolved, cooling the solution to 25 °C, diluting it to the mark with sulfuric acid, and mixing evenly. Measure the flow-through time of a 0.01 g / mL polyamide resin solution at 25 °C through an Ubbelohde viscometer, denoted as t1, and measure the flow-through time of the solvent sulfuric acid with the same viscometer, denoted as t2. t1 / t2 is the relative viscosity.

[0022] Preferably, the nitrogen-based flame retardant includes melamine and / or melamine derivatives.

[0023] Preferably, the melamine derivative includes melamine cyanurate.

[0024] Preferably, the number average molecular weight of the polyethylene glycol is 2000 to 12000; preferably the number average molecular weight is 4000 to 8000, more preferably 5500 to 6500.

[0025] In the present invention, the number average molecular weight of the polyethylene glycol can be tested by a gel permeation chromatograph.

[0026] Preferably, the isocyanurate compounds containing carbon-carbon double bonds include triallyl isocyanurate (TAIC) and / or methyl triallyl isocyanurate (TMAIC), preferably triallyl isocyanurate.

[0027] Preferably, the structural formula of the phosphite compound is P(OR) 3 ; wherein, R is the same or different, and each independently selected from any one of C1-C20 straight-chain or branched-chain alkyl groups, C3-C22 straight-chain or branched-chain alkenyl groups, C6-C40 cycloalkyl groups, C6-C40 aryl groups, C6-C40 alkaryl groups or C6-C40 aralkyl groups.

[0028] In the present invention, C1 - C20 refers to having 1 - 20 carbon atoms, for example, it can be 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 or a range between any of the above values; C3 - C22 refers to having 3 - 22 carbon atoms, for example, it can be 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 21 or a range between any of the above values; C6 - C40 refers to having 6 - 40 carbon atoms, for example, it can be 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40 or a range between any of the above values.

[0029] Preferably, the phosphite compound includes at least one of bis(2,4 - dicumylphenyl)pentaerythritol diphosphite, bis(2,6 - di - tert - butyl - 4 - methylphenyl)pentaerythritol diphosphate, or tris(2,4 - di - tert - butylphenyl)phosphite.

[0030] Preferably, by weight parts, the polyamide composite further includes 0.01 - 0.8 parts of antioxidant and / or 0.01 - 1 part of lubricant; more preferably, the weight of the antioxidant is 0.1 - 0.5 parts, and the weight of the lubricant is 0.2 - 0.8 parts.

[0031] In the present invention, the antioxidant includes one or more of hindered phenol antioxidants, amine antioxidants, cuprous halide composite antioxidants, or antioxidants containing benzophenone functional group compounds. The lubricant includes at least one of hydrocarbon lubricants, ester lubricants, alcohol lubricants, fatty acid lubricants, fatty acid amide lubricants, and metal soap lubricants; preferably ester lubricants, such as fatty acid esters, polyol esters, polyethylene glycol esters, etc.

[0032] In the present invention, other additives can be added to the polyamide composite as needed, such as toughening agents (such as maleic anhydride - grafted styrene - acrylonitrile copolymer), antistatic agents (such as quaternary ammonium salts, etc.), compatibilizers (such as maleic anhydride - grafted polyethylene, maleic anhydride - grafted polyolefin elastomers, etc.), other flame retardants (such as aluminum hydroxide, hypophosphite, etc.), colorants, etc.

[0033] Preferably, the comparative tracking index of the polyamide composite is ≥1.25, and more preferably the comparative tracking index is ≥1.5.

[0034] In the present invention, the mass percentage content of the polyamide resin in the polyamide composite is preferably ≥50%, further preferably ≥60%, and more preferably ≥75%.

[0035] In the second aspect, the present invention provides a preparation method of the polyamide composite according to the first aspect, and the preparation method includes the following steps:

[0036] Mix a polyamide resin, a nitrogen-based flame retardant, polyethylene glycol, an isocyanuric acid ester compound containing a carbon-carbon double bond, and a phosphite compound, and extrude to obtain the polyamide composite material.

[0037] Preferably, the mixed materials further include an antioxidant and / or a lubricant.

[0038] Preferably, the extrusion temperature is 160 - 260 °C.

[0039] In the present invention, the mixing can be carried out in a high-speed mixer; the mixing time is 3 - 10 min; the extrusion is carried out in a twin-screw extruder, and after sufficient plasticization and melting, it is extruded, drawn into strips, cooled, and pelletized to obtain the polyamide composite material. Among them, the screw speed of the twin-screw extruder is 300 - 800 rpm, the length-diameter ratio is 36:1 - 48:1, the temperature of each section of the barrel of the extruder is 160 - 250 °C, and the head temperature is 230 - 260 °C.

[0040] In a third aspect, the present invention provides a high tracking resistance index product, and the high tracking resistance index product includes the polyamide composite material described in the first aspect.

[0041] In the present invention, the high tracking resistance index product can be used in industries such as automobiles, electronic appliances, connectors, and energy storage, meeting the performance requirements of materials in industries such as automobiles, electronic appliances, connectors, and energy storage.

[0042] The numerical ranges described in the present invention not only include the above-listed point values, but also include any point values between the above numerical ranges not listed. Due to space limitations and for the sake of brevity, the specific point values included in the described ranges are not exhaustively listed in the present invention.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] The polyamide composite material provided by the present invention, by adding polyethylene glycol, an isocyanuric acid ester compound containing a carbon-carbon double bond, and a phosphite compound, can not only improve the tracking resistance index of the polyamide composite material, but also ensure that the polyamide composite material has good impact resistance performance, enabling the polyamide composite material to meet the performance requirements of materials in industries such as automobiles, electronic appliances, connectors, and energy storage. Specific Embodiments

[0045] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0046] The materials used in the present invention can be purchased from the market or prepared by conventional methods; unless otherwise specified, the materials used in the present invention are as follows:

[0047] Polyamide resin: polyhexamethylene adipamide (nylon 66), PA66EPR24, relative viscosity 2.4, purchased from Shenma Group.

[0048] Melamine cyanurate (MCA): purchased from Shandong Shouguang Weidong Chemical.

[0049] Polyethylene glycol (PEG)

[0050] PEG-1: number average molecular weight is 3000, PEG-3000, purchased from Dow, USA.

[0051] PEG-2: number average molecular weight is 4000, PEG-4000, purchased from Guangzhou Jinchangsheng Technology Co., Ltd.

[0052] PEG-3: number average molecular weight is 6000, PEG-6000, purchased from Dow, USA.

[0053] PEG-4: number average molecular weight is 8000, PEG-8000, purchased from Guangzhou Fengtian Chemical Co., Ltd.

[0054] PEG-5: number average molecular weight is 10000, PEG-10000, purchased from Guangzhou Rongda Chemical Company.

[0055] Polypropylene glycol: number average molecular weight is 6000, PPG-6000, Shanghai Beko Chemical Co., Ltd.

[0056] Triallyl isocyanurate (TAIC): purchased from Shanghai Fangruida Chemical Co., Ltd.

[0057] Triallyl methyl isocyanurate (TMAIC): brand name FARIDA H-2, purchased from Fangruida Chemical Co., Ltd.

[0058] Phosphite compounds (P)

[0059] P1: bis(2,4-dicumylphenyl)pentaerythritol diphosphite, 608, molecular weight 853, purchased from Qitai Technology Co., Ltd.

[0060] P2: bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, PEP-36, molecular weight 633, purchased from Aidico (China) Investment Co., Ltd.

[0061] P3: tris(2,4-di-tert-butylphenyl) phosphite, RIANOX 168, molecular weight 647, purchased from Tianjin Li'anlong New Materials Co., Ltd.

[0062] Antioxidant: N,N′-1,6-hexanediyl-bis-[3,5-di-tert-butyl-4-hydroxyhydrocinnamide], IRGANOX 1098, a hindered phenolic antioxidant, manufactured by BASF.

[0063] Lubricant: TR044W, an ester lubricant, manufactured by Struktol.

[0064] Examples 1 - 20, Comparative Examples 1 - 6

[0065] Examples 1 - 20 and Comparative Examples 1 - 6 each provide a polyamide composite material. By weight, the formulations of the polyamide composite materials are shown in Tables 1 - 4; among them, " / " indicates that the component is not in the formulation; the preparation method of the polyamide composite material includes: mixing each component in a high-speed mixer for 5 minutes, then adding it to the main feed hopper of a twin-screw extruder, fully plasticizing, melting, extruding, pelletizing, cooling, and cutting to obtain the polyamide composite material. Among them, the screw speed of the twin-screw extruder is 500 rpm, the length-diameter ratio is 44:1, the temperature of each section of the barrel of the extruder is 200 °C, and the temperature of the die head is 245 °C.

[0066] Table 1

[0067]

[0068]

[0069] Table 2

[0070]

[0071] Table 3

[0072]

[0073]

[0074] Table 4

[0075]

[0076] Performance Testing

[0077] The following performance tests were carried out on the polyamide composite materials provided in Examples 1 - 20 and Comparative Examples 1 - 6:

[0078] (1) Tracking Resistance Index (IPT): The polyamide composite material was injection-molded into a 130×50×6 mm sample plate and tested in accordance with the standard of GB / T 4207 - 2022.

[0079] (2) Notched impact strength: According to the test standard of ISO 180-2023, ISO standard test specimens were used.

[0080] The specific test results are shown in Table 5.

[0081] Table 5

[0082]

[0083]

[0084] As can be seen from Table 5, the polyamide composite material provided by the present invention is compounded with polyethylene glycol, isocyanuric acid ester compounds containing carbon-carbon double bonds and phosphite compounds, and by controlling the content of each component within a specific range, the obtained polyamide composite material has a high tracking resistance index and good impact resistance; the tracking resistance index of the polyamide composite material is ≥1.25 V, and the notched impact strength is ≥4.1 kJ / m 2 .

[0085] The specific embodiments described above have further elaborated on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A polyamide composite material, characterized in that: The polyamide composite material comprises, by weight, 33 to 95 parts of polyamide resin, 6 to 18 parts of nitrogen flame retardant, 5 to 15 parts of polyethylene glycol, 0.5 to 3 parts of isocyanurate compounds containing carbon-carbon double bonds and 0.5 to 3 parts of phosphite compounds.

2. The polyamide composite material according to claim 1, characterized in that: The polyamide resin includes at least one of a condensation product of a dibasic acid and a diamine, a condensation product of an aminocarboxylic acid, or a ring-opening polymerization product of a cyclic lactam; Preferably, the polyamide resin comprises polyhexamethylene adipamide and / or polycaprolactam; Preferably, the relative viscosity of the polyamide resin is 2 to 3.

4.

3. The polyamide composite material according to claim 1 or 2, characterized in that: The nitrogen-based flame retardant includes melamine and / or melamine derivatives; Preferably, the melamine derivative comprises melamine cyanurate.

4. The polyamide composite material according to any one of claims 1 to 3, characterized in that: The number average molecular weight of the polyethylene glycol is 2000-12000, preferably 4000-8000.

5. The polyamide composite material according to any one of claims 1 to 4, characterized in that: The isocyanurate compound containing a carbon-carbon double bond includes triallyl isocyanurate and / or methyl triallyl isocyanurate, preferably triallyl isocyanurate.

6. The polyamide composite material according to any one of claims 1 to 5, characterized in that: The structural formula of the phosphite compound is P(OR)3; wherein R is the same or different and is independently selected from any one of C1-C20 straight chain or branched alkyl, C3-C22 straight chain or branched alkenyl, C6-C40 cycloalkyl, C6-C40 aryl, C6-C40 alkaryl or C6-C40 aralkyl; Preferably, the phosphite compound includes at least one of bis(2,4-dicumylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate or tris(2,4-di-tert-butylphenyl)phosphite.

7. The polyamide composite material according to any one of claims 1 to 6, characterized in that: The polyamide composite material further comprises, by weight, 0.01 to 0.8 parts of an antioxidant and / or 0.01 to 1 parts of a lubricant; Preferably, the tracking resistance index of the polyamide composite material is ≥1.25, more preferably ≥1.

5.

8. A method for preparing a polyamide composite material according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The polyamide composite material is obtained by mixing polyamide resin, nitrogen flame retardant, polyethylene glycol, isocyanurate compound containing carbon-carbon double bond and phosphite compound, and extruding.

9. The preparation method according to claim 8, characterized in that: The mixed material also includes an antioxidant and / or a lubricant; Preferably, the extrusion temperature is 160-260°C.

10. A product with a high tracking resistance index, characterized in that: The product with high tracking resistance index comprises the polyamide composite material according to any one of claims 1 to 7.

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