A low-odor flame-retardant polyamide composite material and its preparation method and application

Abstract

The present invention discloses a low-odor flame-retardant polyamide composite material, a preparation method thereof and an application thereof. The polyamide composite material comprises the following components, by weight: 20-60 parts of polyamide resin, 13-30 parts of aluminum diethylphosphinate, 4-10 parts of synergistic flame retardant, 15-40 parts of glass fiber, 1-5 parts of polyethylene glycol and 0.1-2 parts of thermal stabilizing agent. The polyamide composite material of the present invention successfully solves the problem of severe odor of flame-retardant polyamide and has high notched impact strength.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a low-odor flame-retardant polyamide composite material and a preparation method and application thereof. Background Art

[0002] Polyamide, commonly known as nylon, is an important thermoplastic engineering plastic. It is widely used in automobiles, mechanical parts, electronic appliances, home appliances, new energy and other fields because of its many excellent properties such as high strength, good self-lubrication, wear resistance, oil resistance and easy molding and processing. Phosphinate flame retardant polyamide is often used in connectors, low-voltage electrical appliances, energy storage and other industries due to its excellent comprehensive mechanical properties, easy coloring, easy processing, high CTI and other characteristics. However, phosphinate flame retardant polyamide has a heavy odor and is difficult to use in the fields of automobiles, electronic appliances and electrical appliances. Therefore, there is an urgent need for a polyamide composite material with low odor and high impact strength to meet the needs of automobiles, electronic appliances, energy storage, connectors and other industries. Summary of the invention

[0003] In view of the defects in the prior art, the present invention provides a flame-retardant polyamide composite material with low odor and high impact strength, and a preparation method and application thereof.

[0004] The present invention provides a low-odor flame-retardant polyamide composite material, which comprises the following components in parts by weight: 20-60 parts of polyamide resin, such as 20, 25, 30, 40, 45, 55, 60 parts; 13-30 parts of aluminum diethylphosphinate, such as 13, 15, 18, 20, 25, 30 parts; 4-10 parts of synergistic flame retardant, such as 4, 6, 8, 10 parts; 15-40 parts of glass fiber, such as 15, 20, 25, 30, 40 parts; 1-5 parts of polyethylene glycol, such as 1, 2, 3, 5 parts; 0.1-2 parts of heat stabilizing agent, such as 0.1, 0.2, 0.5, 1, 2 parts;

[0005] The mass percentage of the polyamide resin in the composition is 33%-48%.

[0006] Furthermore, the number average molecular weight of the polyethylene glycol is 4000-8000.

[0007] In flame-retardant polyamide composites, the simultaneous addition of polyethylene glycol and thermal stability additives can significantly improve the odor level of halogen-free flame-retardant nylon products.

[0008] Furthermore, the heat stabilizing agent is any one of a phenolic heat stabilizer, a phosphorus-containing heat stabilizer, an amine heat stabilizer, and a copper-containing heat stabilizer. The phenolic heat stabilizer is a molecule containing a phenol group, such as 1010, but not limited to this; the above-mentioned phosphorus-containing heat stabilizer is a molecule containing phosphorus, preferably a phosphorous acid or a phosphite antioxidant, such as bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-ethylenebis(4,6-di-tert-butylbenzene)fluorophosphite, tris(2,4-di-tert-butylphenyl)phosphite, and more preferably 2,2-ethylenebis(4,6-di-tert-butylbenzene)fluorophosphite; the above-mentioned amine heat stabilizer is a molecule containing amine, such as HALS-944, Nyrostab S-EED, but not limited to this; the above-mentioned copper-containing heat stabilizer refers to a mixture stabilizer containing a copper salt and an alkali metal halide and / or an alkaline earth metal halide.

[0009] Furthermore, the heat stabilizing agent is a phosphorus-containing heat stabilizer.

[0010] Furthermore, the polyamide resin is any one of the condensation products of one or more dicarboxylic acids and one or more diamines, the condensation products of one or more aminocarboxylic acids, and the ring-opening polymerization products of one or more cyclic lactams, preferably PA66 or PA610.

[0011] Further, the relative viscosity of the polyamide resin is 2.0-3.4. The relative viscosity of the 0.01g / mL concentrated sulfuric acid solution of the polyamide resin tested at 25°C is 2.0-3.4. The detection method of the relative viscosity is: weigh 0.5g of polyamide resin, transfer it to a 50mL volumetric flask, add about 40mL of 96% mass fraction concentrated sulfuric acid, ultrasonically oscillate until the polyamide resin is completely dissolved, cool the solution to 25°C, dilute to the scale with concentrated sulfuric acid, and mix evenly, test the flow time of 0.01g / mL polyamide resin solution through the Ubbelohde viscometer at 25°C, record it as t1, use the same viscometer to test the flow time of the solvent concentrated sulfuric acid, record it as t2, t1 / t2 is the relative viscosity.

[0012] Furthermore, the synergistic flame retardant is one or more of melamine polyphosphate, melamine aluminum polyphosphate, melamine magnesium polyphosphate, melamine cyanurate, melamine zinc polyphosphate, and zinc borate, preferably melamine polyphosphate and zinc borate.

[0013] The flame retardant of the present invention is a compound of diethyl aluminum hypophosphite and the above synergistic flame retardant, preferably a compound of diethyl aluminum hypophosphite and melamine polyphosphate or melamine polyphosphate aluminum, more preferably a compound of diethyl aluminum hypophosphite and melamine polyphosphate.

[0014] Furthermore, the glass fiber is at least one of E glass fiber, A glass fiber, S glass fiber, D glass fiber, C glass fiber, and quartz glass fiber, preferably alkali-free glass fiber.

[0015] Furthermore, the polyamide composite material further comprises a lubricant, which is at least one of hydrocarbons, esters, alcohols, fatty acids, fatty acid amides, and metal soaps, preferably an ester lubricant, such as fatty acid esters, polyol esters, and polyethylene glycol esters. The lubricant is 0-1 parts by weight.

[0016] The composition of the present invention may further contain color powder without impairing the effects of the present invention, wherein the color powder is 0-2 parts by weight.

[0017] The present invention also provides a method for preparing the polyamide composite material, comprising the steps of mixing, extruding and granulating the components;

[0018] The specific steps are as follows: weigh each component by weight, mix each component except glass fiber in a high mixer for 3-10 minutes, then add the components to the main feed hopper of the twin-screw extruder, add the glass fiber from the side feed hopper of the sixth section of the screw barrel, fully plasticize and melt, extrude, draw, cool, and pelletize to obtain a polyamide composite material. The screw speed of the twin-screw extruder is 300-800rpm, the aspect ratio is 36:1-48:1, the temperature of each section of the screw barrel of the extruder is 160℃-250℃, and the head temperature is 230℃-260℃.

[0019] The invention also provides application of the polyamide composite material in preparing automobile and electronic and electrical appliance materials.

[0020] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0021] (1) The polyamide composite material of the present invention successfully solves the problem of severe odor of flame retardant polyamide.

[0022] (2) The polyamide composite material of the present invention has high notched impact strength. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0024] Example

[0025] The present invention is further described below in conjunction with specific examples and comparative examples. The following specific examples are all preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and are particularly not limited to the types of the various component raw materials used in the following specific examples.

[0026] 1. The sources of raw materials for the embodiments and comparative examples are as follows:

[0027] Polyamide resin #1: nylon 66, brand PA66 EPR24, relative viscosity 2.4, Shenma Group;

[0028] Polyamide resin #2: PA610, brand name PA610 RV26, relative viscosity 2.6, Shanghai Yinggu Chemical Co., Ltd.

[0029] Aluminum diethylphosphinate: brand Exolit OP 1230, Clariant;

[0030] MCA flame retardant: The brand is nitrogen-based flame retardant lubricant MCA, purchased from Sichuan Fine Chemical Research and Design Institute;

[0031] Synergistic flame retardant #1: melamine polyphosphate, brand name Budit 3141, Bode;

[0032] Synergistic flame retardant #2: melamine cyanurate, brand name melamine cyanurate MCA, Shouguang Weidong Chemical;

[0033] Glass fiber: E glass fiber, brand ECS10-03-568H, China Jushi Co., Ltd.

[0034] Polyethylene glycol #1: molecular weight 4000, brand PEG-4000, Guangzhou Jinchangsheng Technology Co., Ltd.;

[0035] Polyethylene glycol #2: molecular weight 8000, brand PEG-8000, Guangzhou Fengtian Chemical Co., Ltd.;

[0036] Polyethylene glycol #3: molecular weight 10000, brand PEG-10000, Guangzhou Rongda Chemical Company;

[0037] Thermal stabilizer #1: amine antioxidant, brand HALS-944, Liansheng Group;

[0038] Thermal Stabilizer #2: Phosphorus-containing thermal stabilizer, 2,2-ethylenebis(4,6-di-tert-butylbenzene)fluorophosphite;

[0039] Thermal Stabilizer #3: Phosphorus-containing thermal stabilizer, tris(2,4-di-tert-butylphenyl) phosphite;

[0040] Thermal stabilizer #4: phosphorus-containing thermal stabilizer, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, brand name PEP-36, Aidico (China) Investment Co., Ltd.;

[0041] Thermal Stabilizer #5: Copper salt antioxidant, brand 8:1:1 Ki / CuI / Zn Stearate Pellets, AJAY;

[0042] Heat Stabilizer #6: Phenolic Antioxidant, brand: 1010, BASF;

[0043] Lubricant: TR044W, ester lubricant, the same substance was used in parallel experiments.

[0044] The preparation method of the polyamide composite material of the embodiment of the present invention and the comparative example comprises the following steps:

[0045] Weigh each component by weight, mix each component except glass fiber in a high mixer for 3-10 minutes, then add it to the main feeding hopper of the twin-screw extruder, add the glass fiber from the side feeding hopper of the sixth section of the screw barrel, fully plasticize and melt it, extrude it, draw it, cool it, and cut it into pellets to obtain a polyamide composite material. The screw speed of the twin-screw extruder is 300-800rpm, the aspect ratio is 36:1-48:1, the temperature of each section of the screw barrel of the extruder is 160℃-250℃, and the head temperature is 230℃-260℃.

[0046] 2. Various performance test methods

[0047] (1) Odor test method:

[0048] The test standard is VW50180-2015, with 5 odor assessors.

[0049] Odor evaluation was performed for all variants according to a rating scale of 1-6, with intermediate scale values ​​also possible.

[0050] Evaluation scale:

[0051] Score: 1: Cannot feel

[0052] Score: 2: Perceptible, not disturbing

[0053] Score: 3: noticeable but not disturbing

[0054] Score: 4 Disturbance

[0055] Score: 5 Strongly disgusted

[0056] Score: 6 Intolerable

[0057] Depending on the test method and the variant used, the individual scores can be given as arithmetic means, with the mean values ​​being divided into half-value grades.

[0058] (2) Notched impact strength test method

[0059] According to the test standard of ISO 180-2019, ISO standard test specimens are used.

[0060] Table 1 Technical solutions and effects of the embodiments (unit: weight parts)

[0061]

[0062] Table 2 Comparative Examples Technical Scheme and Effects (Units are parts by weight)

[0063]

[0064] Comparative Examples 1-5 are all single variables with Example 2. Comparative Examples 1-2 do not add polyethylene glycol or heat stabilizer, and the odor level is worse than Example 2. It is found that polyethylene glycol and heat stabilizer are synergistic in reducing the odor level. The amount of polyethylene glycol in Comparative Example 3 is too much, the amount of heat stabilizer in Comparative Example 4 is too much, and the flame retardant added in Comparative Example 5 is not diethyl aluminum hypophosphite. Polyethylene glycol and heat stabilizer cannot synergistically play a good role in reducing odor in this system. The above comparative examples cannot achieve a lower odor level and a higher notched impact strength at the same time.

[0065] Based on the test data of odor level and notched impact strength in Table 1 and Table 2, the polyamide composite materials prepared by Examples 1-13 have high mechanical properties, and the notched impact strength can reach 7.3 kJ / m 2 , and under the premise that the notched impact strength can meet the conditions, the odor level can reach level 3, which has obvious advantages over the control ratio and can effectively meet the high standards of customers and the market.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-odor flame-retardant polyamide composite material, characterized in that: In parts by weight, it includes the following components: The heat stabilizing agent is any one of a phenolic heat stabilizer, a phosphorus-containing heat stabilizer, an amine heat stabilizer, and a copper-containing heat stabilizer; The synergistic flame retardant is one or more of melamine polyphosphate, melamine aluminum polyphosphate, melamine magnesium polyphosphate, melamine cyanurate, melamine zinc polyphosphate, and zinc borate.

2. The polyamide composite material according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol is 4000-8000.

3. The polyamide composite material according to claim 1, characterized in that: The heat stabilizing agent is a phosphorus-containing heat stabilizer.

4. The polyamide composite material according to claim 1, characterized in that: The polyamide resin is any one of a condensation product of one or more dicarboxylic acids and one or more diamines, a condensation product of one or more aminocarboxylic acids, and a ring-opening polymerization product of one or more cyclic lactams.

5. The polyamide composite material according to claim 3, characterized in that: The polyamide is PA66 or PA610.

6. The polyamide composite material according to claim 1, characterized in that: The relative viscosity of the polyamide resin is 2.0-3.

4.

7. The polyamide composite material according to claim 1, characterized in that: The glass fiber is at least one of E glass fiber, A glass fiber, S glass fiber, D glass fiber, C glass fiber, and quartz glass fiber.

8. The method for preparing the polyamide composite material according to any one of claims 1 to 7, characterized in that: The process comprises the steps of mixing, extruding and granulating the components.

9. Use of the polyamide composite material according to any one of claims 1 to 7 in the preparation of automobile and electronic and electrical materials.

Images