Polyamide composite material as well as preparation method and application thereof

Abstract

The invention discloses a polyamide composite material as well as a preparation method and application thereof. The polyamide composite material comprises the following components in parts by weight: 28-75 parts of polyamide resin; 3-10 parts of a gas phase reinforcing agent; 8-22 parts of an organic phosphorus flame retardant; 3-12 parts of a synergistic flame retardant; 8 to 32 parts of reinforcing fiber; wherein the gas phase enhancer comprises a compound containing a sulfonamide group, and melem and / or melam, and the mass ratio of the compound containing the sulfonamide group to the melem and / or melam is (0.5-3): 1. According to the invention, the compound containing the sulfonamide group and the melem and / or the melam in a specific mass ratio are added into the polyamide resin to serve as the gas phase enhancer, so that the glowing filament performance of the composite material can be improved, the mechanical property is better, and the mold scale is less.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastics, and more specifically, to a polyamide composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Polyamide resins have excellent mechanical properties, outstanding barrier properties, good heat resistance, wear resistance, and chemical resistance, and are widely used in the machinery manufacturing industry, power tool industry, electronic and electrical fields, and transportation industry. In the manufacturing of electronic and electrical products, polyamide materials not only need to meet the basic physical and chemical performance requirements, but also must have certain fire safety performance to meet the increasingly strict industry standards and safety specifications. Traditionally, halogen flame retardants have been widely used due to their high flame retardant effect, but their non-environmental protection properties, low CTI values, etc. limit their further application.

[0003] In recent years, halogen-free flame retardant reinforced polyamide materials have been widely favored in the electronic and electrical fields, especially in the connector industry. With the rapid development of the household appliance connector industry towards high voltage and high safety, more stringent requirements are put forward for the electrical properties and flame retardant properties of materials. For example, according to the glow wire test (GWIT) carried out in accordance with the IEC 60695-2-11 standard, the test temperature of the material is required to reach or exceed 775 °C to ensure good flame retardant performance under extreme conditions. In the prior art, the glow wire flame retardant performance is often improved by adjusting the type and content of the flame retardant or by using a flame retardant compounding technology. However, although increasing the content of the flame retardant can effectively improve the glow wire flame retardant performance, it will cause problems such as mold fouling during the extrusion and injection molding processes, and the precipitation of the flame retardant during the use of the parts, affecting the long-term stability and safety of the product. In addition, filling with inorganic substances such as magnesium hydroxide can improve the flame retardant performance to a certain extent, but it often has an adverse effect on the mechanical properties of the material, limiting its application in occasions with high-precision and high-strength requirements. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects or deficiencies of the halogen-free flame retardant reinforced polyamide composite material in the prior art as described above, and to provide a polyamide composite material.

[0005] Another purpose of the present invention is to provide a preparation method of the polyamide composite material.

[0006] Another purpose of the present invention is to provide an application of the polyamide composite material.

[0007] To achieve the above purpose, the present invention is realized by adopting the following technical solutions:

[0008] A polyamide composite material, comprising the following components calculated by weight:

[0009]

[0010] Among them, the gas-phase enhancer includes a sulfonamide group-containing compound, and melem and / or melam. The mass ratio of the sulfonamide group-containing compound to melem and / or melam is (0.5-3):1.

[0011] The present invention provides a polyamide composite material. By using a sulfonamide group-containing compound and melem and / or melam with a specific mass ratio as the gas-phase enhancer, free radicals can be quenched, the amount of initial free radicals generated in the condensed phase can be reduced. The sulfonamide group-containing compound can prolong the glow wire ignition time, and melem and / or melam can dilute the concentration of combustible gas, delay the process of the combustible gas reaching the critical explosion concentration, and adjusting the ratio of the two can significantly improve the glow wire flame retardancy of the composite material without increasing mold fouling in the condensed-phase carbonization flame retardant system of the organophosphorus flame retardant.

[0012] It should be noted that in the polyamide composite material of the present invention, the content of the polyamide resin is preferably not less than 25 wt%.

[0013] In the present invention, the mass ratio of the sulfonamide group-containing compound to melem and / or melam is (0.5-3):1, such as but not limited to 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1 or 3:1, etc., and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0014] Further, the mass ratio of the sulfonamide group-containing compound to melem and / or melam is (1-2):1.

[0015] In the present invention, the gas-phase enhancer is 3-10 parts, such as but not limited to 3 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5 parts, 5.2 parts, 5.5 parts, 5.8 parts, 6 parts, 6.2 parts, 6.5 parts, 6.8 parts, 7 parts, 7.2 parts, 7.5 parts, 7.8 parts, 8 parts, 8.2 parts, 8.5 parts, 8.8 parts, 9 parts, 9.2 parts, 9.5 parts, 9.8 parts or 10 parts, etc., and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the specific point values included in the scope of the present invention are not exhaustively listed herein.

[0016] Further, the structural formula of the sulfonamide group-containing compound is Among them, R 1 is selected from C1-C4 alkyl, phenyl, aromatic substituents; R 2Selected from hydrogen, C1-C4 alkyl, C1-C4 alkylamino, phenyl, aromatic substituent, C4-C5 heterocyclic group;

[0017] Furthermore, R 1 Selected from phenyl, aromatic substituent; R 2 Selected from phenyl, aromatic substituent.

[0018] In some preferred embodiments, the aromatic substituent is tolyl or chlorophenyl.

[0019] Furthermore, the initial decomposition temperature of the sulfonamide group-containing compound is ≥ 300 °C.

[0020] Specifically, the initial decomposition temperature of the sulfonamide group-containing compound is ≥ 300 °C, such as but not limited to ≥ 300 °C, 305 °C, 310 °C, 315 °C, 320 °C, 325 °C, 330 °C, 335 °C, 340 °C, 345 °C, 350 °C, 355 °C or 360 °C, etc., as well as the specific point values between the above point values. For the sake of brevity and limited space, the specific point values included in the scope are not exhaustively listed in the present invention.

[0021] Furthermore, the initial decomposition temperature of the sulfonamide group-containing compound is 310-340 °C.

[0022] Specifically, the test standard for the initial decomposition temperature of the sulfonamide compound is GB / T 33047.1-2016.

[0023] Specifically, the sulfonamide group-containing compound includes one or more of N-(3-piperidyl)methanesulfonamide, N-(2-aminoethyl)-4-methylbenzenesulfonamide, N-(4-chlorophenyl)benzenesulfonamide, N-phenylbenzenesulfonamide or benzenesulfonamide.

[0024] Furthermore, the average particle size of melem and / or melam is ≤ 15 μm.

[0025] Specifically, the average particle size of melem and / or melam is 5-15 μm.

[0026] Furthermore, the initial decomposition temperature of melem and / or melam is ≥ 375 °C.

[0027] Furthermore, the initial decomposition temperature of melem and / or melam is 380-430 °C.

[0028] Specifically, the test standard for the initial decomposition temperature of melem and / or melam is GB / T 33047.1-2016.

[0029] Furthermore, the polyamide composite material comprises the following components calculated by weight:

[0030]

[0031] Furthermore, the organophosphorus flame retardant includes aluminum diethylphosphinate, aluminum dipropylphosphinate, aluminum phenylphosphinate, aluminum methyl ethylphosphinate, aluminum methyl phenylphosphinate, and aluminum carboxyethyl phenylphosphinate.

[0032] Furthermore, the synergistic flame retardant includes melamine polyphosphate and / or zinc borate.

[0033] Furthermore, the average particle size of the synergistic flame retardant is 2 - 5 μm.

[0034] Specifically, the melamine polyphosphate includes one or more of melamine polyphosphate, melamine aluminum polyphosphate, melamine magnesium polyphosphate, or melamine zinc polyphosphate.

[0035] Furthermore, the reinforcing fiber includes glass fiber and / or carbon fiber.

[0036] Furthermore, the average length of the reinforcing fiber is 3 - 6 mm.

[0037] Furthermore, the polyamide resin includes one or more of aliphatic polyamide resin and / or aromatic polyamide resin.

[0038] Specifically, the aliphatic polyamide resin is one or more of PA66, PA610, PA612, PA1010, PA1012, PA1212, PA6, PA7, PA11, PA12, PAPACM12.

[0039] The aromatic polyamide resin is one or more of PA6T, PA9T, PA10T, PA11T, PA12T, PA13T, PA6T / 6I, PA6T / 6I / 66, PA6I, PA6I / 6T, PA10T / 66, PA10T / 1010, PA10T / 10I, PPTA.

[0040] Furthermore, the relative viscosity of the polyamide resin is 2.0 - 2.8.

[0041] Furthermore, the test standard for the relative viscosity is ASTM D789 - 19.

[0042] Furthermore, the polyamide composite material further includes 0.1 - 5 parts of additives.

[0043] Furthermore, the additive is an antioxidant and / or a lubricant.

[0044] In the present invention, common antioxidants can be selected according to the prior art, such as, but not limited to, one or more of hindered phenol antioxidants, phosphite antioxidants, diphenylamine antioxidants or thioether antioxidants.

[0045] Specifically, the hindered phenol antioxidants are one or more of N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076) or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acryloyl]-1,1-dimethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane (ADK AO-80).

[0046] The phosphite antioxidants are one or more of tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite (PEP-36) or 627A.

[0047] The diphenylamine antioxidant is 4,4'-bis(α,α'-dimethylbenzyl)diphenylamine.

[0048] The thioether antioxidants are one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol tetrakis(3-laurylthiopropionate).

[0049] In the present invention, common lubricants can be selected according to the prior art. Such as, but not limited to, one or more of stearic acid lubricants, polyethylene lubricants, amide lubricants, paraffin wax lubricants, ester lubricants or silicone lubricants.

[0050] Specifically, the stearic acid lubricants can be calcium stearate and / or zinc stearate.

[0051] The polyethylene lubricants can be polyethylene wax.

[0052] The amide lubricants can be one or more of oleic acid amide lubricants, EBS amide lubricants or erucic acid amide lubricants.

[0053] The ester lubricants can be aliphatic stearic acid esters, such as oleic acid-based aliphatic polyesters and / or erucic acid-based aliphatic polyesters.

[0054] The silicone lubricant may be polydimethylsiloxane.

[0055] The present invention also protects a method for preparing the above polyamide composite material, comprising the following steps:

[0056] Mix each component evenly to obtain a premix, and subject the premix to melt blending and extrusion granulation to obtain a voltage-resistant nylon composition.

[0057] Further, the extrusion granulation is carried out in a twin-screw extruder.

[0058] Further, the ratio of the screw length to the diameter of the twin-screw extruder is 40-48:1.

[0059] Further, the barrel temperature of the twin-screw extruder is 270-300 °C.

[0060] Further, the screw rotation speed of the twin-screw extruder is 150-400 rpm.

[0061] The present invention also protects the application of the above polyamide composite material in the field of electronic and electrical. In particular, the above polyamide composite material has a component with good glow wire flame retardant performance. In particular, it is used in the preparation of materials such as connectors.

[0062] Compared with the prior art, the beneficial effects of the present invention are:

[0063] The present invention provides a polyamide composite material. By adding a compound containing a sulfonamide group and melamine and / or melem to the polyamide resin, and adjusting the ratio of the two, the glow wire performance of the polyamide composite material can be improved, and there is less mold fouling and better mechanical properties. Specific Embodiments

[0064] The following further illustrates the present invention in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw material reagents used in the embodiments of the present invention are conventional raw material reagents purchased.

[0065] 1. Raw materials used in each embodiment and comparative example of the present invention:

[0066] Polyamide resin:

[0067] Polyamide resin 1: PA66, PA66 U4800 NC01 SS, purchased from Invista;

[0068] Polyamide resin 2: PA56, 1273, purchased from Kaisai Biomaterials Co., Ltd.;

[0069] Gas-phase enhancer:

[0070] Gas-phase enhancer A1: N-(2-aminoethyl)-4-methylbenzenesulfonamide, CAS No. 14316-16-6, purchased from Aladdin;

[0071] Gas-phase enhancer A2: N-(4-chlorophenyl)benzenesulfonamide, CAS No. 4750-28-1, purchased from Aladdin;

[0072] Gas-phase enhancer A3: N-(3-piperidyl)methanesulfonamide, CAS No. 944068-21-7, purchased from Aladdin;

[0073] Gas-phase enhancer B1: Melamine, Sichuan Research and Design Institute of Fine Chemical Industry;

[0074] Gas-phase enhancer B2: Melamine cyanurate, Shaanxi Didu Pharmaceutical Chemical Co., Ltd.;

[0075] Magnesium hydroxide, 10, Jiangsu Aiteke Flame Retardant Materials Co., Ltd.;

[0076] Organic phosphorus flame retardant: Aluminum diethylphosphinate, Exolit OP 1230, purchased from Clariant;

[0077] Synergistic flame retardant:

[0078] Synergistic flame retardant 1: Melamine polyphosphate, Budit 3141, purchased from Bode;

[0079] Synergistic flame retardant 2: Zinc borate, HT-261, Shandong Taixing New Materials Co., Ltd.;

[0080] Reinforcing fiber: Glass fiber, S1HM435TM-10-3, average length 3 mm, purchased from Taishan Fiberglass Co., Ltd.;

[0081] Auxiliary agent:

[0082] Antioxidant: Inganox@1098; Lubricant: LOXIOL G32; Both the antioxidant and the lubricant are commercially available, and the same antioxidant and lubricant are used in the parallel experiments of the examples and the comparative examples.

[0083] 2. The polyamide composites described in each example and comparative example are prepared according to the formulations in Tables 1-2 by the following preparation method:

[0084] Mix each component evenly to obtain a premix, and put the premix into a twin-screw extruder for melt blending and extrusion granulation to obtain a polyamide composite; the length-diameter ratio of the screw of the twin-screw extruder is 40-48:1; the barrel temperature of the twin-screw extruder is 270-300 °C, and the screw speed of the twin-screw extruder is 150-400 rpm.

[0085] 3. Test methods:

[0086] (1) Flame retardancy test: The polyamide composites in each example and comparative example were injection-molded into splines with dimensions of 125 mm × 13 mm × 1.0 mm, and the flame retardancy test was carried out with reference to the UL 94-2013 standard;

[0087] (2) Glow wire ignition temperature test: The polyamide composites in each example and comparative example were injection-molded into square plates with dimensions of 60 mm × 60 mm × 1 mm, and the test was carried out with reference to the IEC 60695-2-13:2021 standard;

[0088] (3) Mold fouling test: The polyamide composites in each example and comparative example were injection-molded at 300 °C. When 200 molds were continuously injection-molded, the mold fouling on the mold was collected and weighed;

[0089] (4) Notched impact strength test: The polyamide composites in each example and comparative example were injection-molded into splines with dimensions of 80 mm × 10 mm × 4 mm, and the test was carried out with reference to the ISO 180:2019 standard. The notch type was A type. Examples 1 to 12 and Comparative Examples 1 to 4

[0090] Table 1 Dosages of each component in the polyamide composites in Examples 1 to 12 (unit: parts by weight) and properties

[0091]

[0092]

[0093] Table 2 Dosages of each component in the polyamide composites in Comparative Examples 1 to 4 (unit: parts by weight) and properties

[0094]

[0095]

[0096] It can be seen from Table 1 that the polyamide composites prepared by the present invention have good glow wire flame retardancy, less mold fouling, and better mechanical properties; specifically: the glow wire temperature is not lower than 775 °C, and all can reach the 1.0 mm V-0 grade, the mold fouling does not exceed 2.6 mg, and the notched impact strength is not lower than 11.5 kJ / m 2 .

[0097] It can be seen from Examples 1 to 4 that by introducing a compound containing a sulfonamide group and compounding it with melem and / or melam, the glow wire performance can be effectively improved, and the polyamide composite prepared with the mass ratio of (1 to 2):1 has better comprehensive performance.

[0098] It can be seen from Comparative Examples 1 and 2 that when the proportion of the gas-phase enhancer is too low or too high, the glow wire performance of the prepared polyamide composite material decreases, and when the amount of gas-phase enhancer B is large, the mold fouling increases.

[0099] It can be seen from Comparative Example 3 that if other flame retardants are used for filling, the glow wire performance requirements cannot be met, and the mechanical properties will decrease.

[0100] It can be seen from Comparative Example 4 that if the gas-phase enhancer is not added and the content of the synergistic flame retardant is increased, the decomposition of the synergistic flame retardant will cause an increase in mold fouling, and the improvement of the glow wire performance is limited.

[0101] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A polyamide composite material, characterized in that: The composition comprises the following components calculated by weight: The gas phase enhancer comprises a compound containing a sulfonamide group, and melem and / or melam, and the ratio of the mass of the compound containing a sulfonamide group to the mass of melem and / or melam is (0.5-3):

1.

2. The polyamide composite material according to claim 1, characterized in that: The ratio of the mass of the compound containing sulfonamide groups to the mass of melem and / or melam is (1-2):

1.

3. The polyamide composite material according to claim 1 or 2, characterized in that: The structural formula of the compound containing sulfonamide group is Among them, R1 is selected from C1-C4 alkyl, phenyl, and aromatic substituents; R2 is selected from hydrogen, C1-C4 alkyl, C1-C4 alkylamino, phenyl, aromatic substituents, and C4-C5 heterocyclic groups; preferably, R1 is selected from phenyl and aromatic substituents; R2 is selected from phenyl and aromatic substituents.

4. The polyamide composite material according to claim 1 or 2, characterized in that: The sulfonamide group-containing compound includes one or more of N-(3-piperidinyl)methanesulfonamide, N-(2-aminoethyl)-4-methylbenzenesulfonamide, N-(4-chlorophenyl)benzenesulfonamide, N-phenylbenzenesulfonamide or benzenesulfonamide.

5. The polyamide composite material according to claim 1, characterized in that: The organic phosphorus flame retardant includes aluminum diethylphosphinate, aluminum dipropylphosphinate, aluminum phenylphosphinate, aluminum methylethylphosphinate, aluminum methylphenylphosphinate, and aluminum carboxyethylphenylphosphinate.

6. The polyamide composite material according to claim 1, characterized in that: The synergistic flame retardant includes melamine polyphosphate and / or zinc borate.

7. The polyamide composite material according to claim 1, characterized in that: The reinforcing fibers include glass fibers and / or carbon fibers.

8. The polyamide composite material according to claim 1, characterized in that: It also includes 0.1 to 5 parts of auxiliary agents.

9. A method for preparing the polyamide composite material according to any one of claims 1 to 8, characterized in that: The steps include: The components are mixed uniformly to obtain a premix, and the premix is ​​melt-blended and extruded to granulate to obtain a voltage-resistant nylon composition.

10. Use of the polyamide composite material according to any one of claims 1 to 8 in the field of electronics and electrical appliances.

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