Polyamide composite material, method for producing same, and use thereof

Abstract

The present application provides a kind of polyamide composite material and its preparation method and application, and the polyamide composite material includes 33-95 parts of polyamide resin, 6-18 parts of nitrogen flame retardant, 5-15 parts of polyethylene glycol, 0.5-3 parts of carbon-carbon double bond containing isocyanuric acid ester compound and 0.5-3 parts of phosphite compound by weight.The polyamide composite material in the present application solves the problem of low electric tracking index and poor impact resistance of the existing nitrogen flame-retardant polyamide composite material.

Description

TECHNICAL FIELD

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

[0002] Polyamide, commonly known as nylon, is an important thermoplastic engineering plastic, which is widely used in the fields of automobiles, mechanical parts, electronics and electrical appliances, home appliances, new energy, etc. due to its high strength, good self-lubricating property, wear resistance, oil resistance and easy molding processing, etc. In order to improve the flame retardant property of polyamide, a flame retardant, such as a nitrogen-based flame retardant, a phosphorus-based flame retardant, etc. is usually added; among them, the nitrogen-based flame-retardant polyamide is often used in connectors, low-voltage electrical appliances, energy storage industries due to its excellent comprehensive mechanical properties, easy coloring, easy processing, high tracking index (CTI), etc. However, the nitrogen-based flame-retardant polyamide has a low tracking resistance index (IPT), and it is difficult to be applied in the fields of automobiles, electronics and electrical appliances, etc. Moreover, in order to improve the IPT of the polyamide material, the mechanical properties of the polyamide material are usually lost, such as the impact strength is reduced.

[0003] Therefore, it is an urgent problem to be solved in the field to develop a nitrogen-based flame-retardant polyamide composite material with high IPT and good impact resistance. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a polyamide composite material and a preparation method and application thereof. The polyamide composite material solves the problems of low tracking resistance index and poor impact resistance of the nitrogen-based flame-retardant polyamide composite material in the prior art.

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

[0006] In the first aspect, the present application provides a polyamide composite material, which comprises, by weight, 33-95 parts of a polyamide resin, 6-18 parts of a nitrogen-based flame retardant, 5-15 parts of a polyethylene glycol, 0.5-3 parts of an isocyanurate compound containing carbon-carbon double bond, and 0.5-3 parts of a phosphite compound.

[0007] In the present application, the polyethylene glycol, the isocyanurate compound containing carbon-carbon double bond and the phosphite compound are compounded, and the content of each component is controlled within a specific range, which not only improves the tracking resistance index of the polyamide composite material, but also ensures that the polyamide composite material has good impact resistance.

[0008] In the present application, 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 application, the weight of the nitrogen-based flame retardant is preferably 6.8-16.6 parts, more preferably 7.7-13.7 parts.

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

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

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

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

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

[0015] In the present application, the diacid comprises at least one of an aliphatic diacid, an alicyclic diacid, or an aromatic diacid; the aliphatic diacid comprises a C4-C20 diacid, 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 diacid comprises 1,4-cyclohexanedicarboxylic acid; the aromatic diacid comprises terephthalic acid, isophthalic acid, phthalic acid, furan dicarboxylic acid, etc.; the diacid can be used alone or at least two kinds can be mixed to form a condensation product with a diamine.

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

[0017] In the present application, the aminocarboxylic acid can be used alone or at least two kinds can be mixed; the aminocarboxylic acid exemplarily comprises iminodiacetic acid, etc.; the lactam can be used alone or at least two kinds can be mixed, exemplarily comprising caprolactam.

[0018] Preferably, the polyamide resin comprises poly(hexamethylene adipate) and / or polycaprolactam.

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

[0020] In the present application, the relative viscosity of the polyamide resin is the relative viscosity of a 0.01 g / mL polyamide resin solution in concentrated sulfuric acid tested at 25°C.

[0021] The method for testing the relative viscosity comprises: weighing 0.5 g of the polyamide resin, transferring it into a 50 mL volumetric flask, adding about 40 mL of 96% mass fraction concentrated sulfuric acid, ultrasonic oscillation until the polyamide resin is completely dissolved, cooling the solution to 25°C, diluting to the scale with concentrated sulfuric acid, and mixing uniformly, testing the flow time of the 0.01 g / mL polyamide resin solution at 25°C through the Ubbelohde viscometer, recorded as t1, testing the flow time of the solvent concentrated sulfuric acid with the same viscometer, recorded as t2, and t1 / t2 is the relative viscosity.

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

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

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

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

[0026] Preferably, the isocyanurate compound containing carbon-carbon double bond comprises triallyl isocyanurate (TAIC) and / or methyl triallyl isocyanurate (TMAIC), preferably triallyl isocyanurate.

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

[0028] In the present application, C1-C20 refers to the number of carbon atoms being 1-20, 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 the number of carbon atoms being 3-22, 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 the number of carbon atoms being 6-40, 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 diphosphite or tris(2,4-di-tert-butylphenyl) phosphite.

[0030] Preferably, the polyamide composite further includes 0.01-0.8 parts by weight of an antioxidant and / or 0.01-1 parts by weight of a 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 application, the antioxidant includes one or more of a hindered phenol antioxidant, an amine antioxidant, a cuprous halide complex antioxidant or an antioxidant containing a benzophenone functional group. The lubricant includes at least one of a hydrocarbon lubricant, an ester lubricant, an alcohol lubricant, a fatty acid lubricant, a fatty acid amide lubricant, a metal soap lubricant; preferably, the ester lubricant is a fatty acid ester, a polyhydric alcohol ester, a polyethylene glycol ester or the like.

[0032] In the present application, the polyamide composite can further include other additives as needed, such as a toughening agent (e.g., a maleic anhydride grafted styrene-acrylonitrile copolymer), an antistatic agent (e.g., a quaternary ammonium salt or the like), a compatibilizer (e.g., a maleic anhydride grafted polyethylene, a maleic anhydride grafted polyolefin elastomer or the like), other flame retardants (e.g., aluminum hydroxide, hypophosphite or the like), a colorant or the like.

[0033] Preferably, the polyamide composite has an electrical tracking index ≥1.25, more preferably, the electrical tracking index ≥1.5.

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

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

[0036] The polyamide resin, nitrogen-based flame retardant, polyethylene glycol, isocyanuric acid ester compound containing carbon-carbon double bond and phosphite compound are mixed and extruded to obtain the polyamide composite material.

[0037] Preferably, the mixed material further comprises antioxidant and / or lubricant.

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

[0039] In the present application, 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 the polyamide composite material is prepared by extrusion, drawing, cooling and granulation after sufficient plasticization and melting. The screw rotation speed of the twin-screw extruder is 300-800 rpm, the length-diameter ratio is 36:1-48:1, the screw cylinder temperature of each section of the extruder is 160-250℃, and the die temperature is 230-260℃.

[0040] In a third aspect, the present application provides a high tracking index resistant product, which comprises the polyamide composite material of the first aspect.

[0041] In the present application, the high tracking index resistant product can be used in the automobile, electronic and electrical, connector, energy storage and other industries to meet the performance requirements of materials in the automobile, electronic and electrical, connector, energy storage and other industries.

[0042] The numerical range in the present application not only includes the point values listed above, but also includes any point values between the above numerical ranges that are not listed. Due to the limited space and for the sake of simplicity, the present application does not exhaustively list the specific point values included in the range.

[0043] Compared with the prior art, the present application has the following advantages:

[0044] The polyamide composite material provided by the present application can not only improve the tracking index resistance of the polyamide composite material, but also ensure good impact resistance of the polyamide composite material, so that the polyamide composite material can meet the performance requirements of materials in the automobile, electronic and electrical, connector, energy storage and other industries. DETAILED DESCRIPTION

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

[0046] All materials used in this invention are commercially available or prepared using conventional methods; unless otherwise specified, the materials used in this 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 Co., Ltd.

[0049] Polyethylene glycol (PEG)

[0050] PEG-1: Number average molecular weight is 3000. PEG-3000 was purchased from Dow Chemical Company, USA.

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

[0052] PEG-3: Number average molecular weight of 6000, PEG-6000, purchased from Dow Chemical Company, USA.

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

[0054] PEG-5: Number average molecular weight of 10,000, PEG-10000, purchased from Guangzhou Rongda Chemical Co., Ltd.

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

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

[0057] Methyltriallyl 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 Chi Tai Technology Co., Ltd.

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

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

[0062] Antioxidant: N,N'-1,6-hexylidene-bis-[3,5-di-tert-butyl-4-hydroxybenzylamide], IRGANOX 1098, hindered phenolic antioxidant, manufacturer: BASF.

[0063] Lubricant: TR044W, ester lubricant, manufacturer: Struktol.

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

[0065] Examples 1-20, Comparative Examples 1-6 respectively provide a polyamide composite material, the formulation of the polyamide composite material is shown in Tables 1-4 in parts by weight; wherein " / " indicates that there is no component in the formulation; the preparation method of the polyamide composite material comprises: mixing the components in a high-speed mixer for 5 min, then adding a twin-screw extruder main feeding hopper, extruding, drawing, cooling, and granulating after fully plasticizing and melting to obtain the polyamide composite material. The screw rotation speed of the twin-screw extruder is 500 rpm, the length-diameter ratio is 44:1, the barrel temperature of each section of the extruder is 200℃, and the head temperature is 245℃.

[0066] Table 1

[0067]

[0068]

[0069] Table 2

[0070]

[0071] Table 3

[0072]

[0073]

[0074] Table 4

[0075]

[0076] Performance test

[0077] The polyamide composite materials provided by Examples 1-20 and Comparative Examples 1-6 are tested for the following properties:

[0078] (1) Index of resistance to tracking (IPT): The polyamide composite material is injection molded into a sample plate of 130x50x6mm, and tested according to the GB / T 4207-2022 standard.

[0079] (2) Notched impact strength: according to the test standard of ISO 180-2023, ISO standard test bars are 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 provided by the application is compounded by polyethylene glycol, isocyanuric acid ester compound containing carbon-carbon double bond and phosphite compound, and the content of each component is controlled within a specific range, so that the polyamide composite has high electrical tracking index and good impact resistance; the electrical tracking index of the polyamide composite is ≥1.25V, and the notched impact strength is ≥4.1kJ / m 2 .

[0085] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the application, and it should be understood that the above only describes specific embodiments of the application and is not intended to limit the application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A polyamide composite, characterized in that, The polyamide composite comprises 33-95 parts by weight of a polyamide resin, 6-18 parts by weight of a nitrogen-based flame retardant, 5-15 parts by weight of a polyethylene glycol, 0.5-3 parts by weight of a carbon-carbon double bond-containing isocyanurate compound, and 0.5-3 parts by weight of a phosphite compound; The nitrogen-based flame retardant comprises melamine and / or a melamine derivative; The carbon-carbon double bond-containing isocyanurate compound comprises triallyl isocyanurate and / or methyl triallyl isocyanurate; The phosphite compound comprises at least one of bis(2,4-dicumylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, or tris(2,4-di-tert-butylphenyl) phosphite.

2. The polyamide composite according to claim 1, characterized in that, The polyamide resin comprises at least one of a condensation product of a diacid and a diamine, a condensation product of an aminocarboxylic acid, or a ring-opening polymerization product of a lactam.

3. The polyamide composite according to claim 2, characterized in that, The polyamide resin comprises polyhexamethylene adipamide and / or polycaprolactam.

4. The polyamide composite of claim 1, wherein, The polyamide resin has a relative viscosity of 2-3.4; The relative viscosity of the polyamide resin is a relative viscosity of a 0.01 g / mL polyamide resin solution in concentrated sulfuric acid tested at 25°C; The method for testing the relative viscosity comprises: weighing 0.5 g of the polyamide resin, transferring it into a 50 mL volumetric flask, adding 40 mL of 96% mass fraction concentrated sulfuric acid, ultrasonic oscillation until the polyamide resin is completely dissolved, cooling the solution to 25°C, diluting to the calibration mark with concentrated sulfuric acid, and mixing uniformly, testing the flow time of the 0.01 g / mL polyamide resin solution through an Ubbelohde viscometer at 25°C, recording it as t1, testing the flow time of the solvent concentrated sulfuric acid through the same viscometer, recording it as t2, and t1 / t2 is the relative viscosity.

5. The polyamide composite of claim 1, wherein, The melamine derivative comprises melamine cyanurate.

6. The polyamide composite of claim 1, wherein, The polyethylene glycol has a number average molecular weight of 2000-12000.

7. The polyamide composite according to claim 6, characterized in that The polyethylene glycol has a number average molecular weight of 4000-8000.

8. The polyamide composite of claim 1, wherein, The carbon-carbon double bond-containing isocyanurate compound is triallyl isocyanurate.

9. The polyamide composite of claim 1, wherein, The polyamide composite further comprises 0.01-0.8 parts by weight of an antioxidant and / or 0.01-1 parts by weight of a lubricant.

10. A process for the production of a polyamide composite according to any one of claims 1 to 8, characterized in that The preparation method comprises the following steps: The polyamide resin, the nitrogen-based flame retardant, the polyethylene glycol, the carbon-carbon double bond-containing isocyanurate compound, and the phosphite compound are mixed and extruded to obtain the polyamide composite.

11. The method of claim 10, wherein, The mixed material further comprises the antioxidant and / or the lubricant.

12. The method of claim 10, wherein, The extrusion temperature is 160-260°C.

13. A high tracking index article of manufacture characterized by The high tracking resistance index product comprises the polyamide composite according to any one of claims 1-9.

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