Flame-retardant V0 PA66 resistant to high and low temperature circulation

Abstract

The invention discloses flame-retardant V0PA66 resistant to high and low temperature circulation. In a nylon 66 system, an MAC flame retardant which is treated by a silane coupling agent and prepared by a semi-dry method (urea method) can be more firmly connected with an interface of a nylon 66 matrix through a bridging effect of the coupling agent, and can be more uniformly dispersed in nylon matrix resin, so that the flame-retardant V0PA66 resistant to the high and low temperature circulation is more uniform, and the flame-retardant V0PA66 resistant to the high and low temperature circulation and the flame-retardant V0PA66 resistant to the high and low temperature circulation are more stable. The agglomeration effect in nylon resin can be reduced, stress concentration fracture at agglomeration points caused by agglomeration is avoided, and the material is easier to crack at the agglomeration points when being collided by external force; and through experimental comparison, a relatively good flame-retardant effect can be achieved through a relatively small addition amount, and the influence of the flame retardant on the mechanical properties, especially the low-temperature toughness, of the material can be reduced if the addition amount is small, so that a matrix material can keep relatively good low-temperature toughness and has relatively good high-low-temperature cycle resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering plastic modification, and in particular to a high and low temperature resistant cyclic flame retardant V0PA66. Background Art

[0002] Terminals are an electronic connector in electronic component systems, usually divided into socket type, snap-on type, screw type, etc., which can connect electrical equipment, line connections and terminals. Its application fields are very wide, such as communications, new energy, electrical control, automotive electronics, etc. The main functions of terminals are as follows: ① Realize circuit connection: Terminals can connect wires or cables in the circuit with equipment or other circuits; ② Realize circuit fixation: Terminals can firmly connect wires or cables to equipment, and are not easy to fall off or loosen; ③ Realize circuit protection: Terminals can effectively prevent wires from contacting the outside world, loosening, leakage, etc., improve the safety and reliability of the circuit, and are an indispensable part of electronics and electronic component systems.

[0003] At present, the engineering plastics used to prepare terminals are mainly based on PA66, and diethyl aluminum hypophosphite is used for toughening and flame retardancy. However, diethyl aluminum hypophosphite has poor fluidity and high cost, and there is a greater risk of precipitation after product color matching. Melamine cyanurate is also used as a flame retardant for nylon 66. Whether it is prepared by the urea method (semi-dry method) or the cyanuric acid method (wet method), its addition will have a greater adverse effect on the low-temperature toughness of the material, resulting in the problem of poor low-temperature toughness of the material. Summary of the invention

[0004] Based on the above background, the present invention provides a high and low temperature cyclic flame retardant V0PA66, which uses melamine cyanurate treated with a silane coupling agent as a flame retardant, which is more evenly dispersed in the matrix, and a small amount of addition can achieve a good flame retardant effect, and has little effect on the mechanical properties, especially the low-temperature toughness.

[0005] The technical solution of the present invention is:

[0006] A high and low temperature resistant cyclic flame retardant V0PA66, which is made of the following raw materials in parts by weight:

[0007]

[0008] Furthermore, the MCA flame retardant is modified by a silane coupling agent.

[0009] Furthermore, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

[0010] Furthermore, the operation of treating the MCA flame retardant with a silane coupling agent comprises the following steps:

[0011] 1) Take MCA flame retardant, and spray silane coupling agent onto melamine cyanurate in a spraying manner while stirring;

[0012] 2) After natural drying, the particles are treated with an ultrasonic vibration screen and oversized particles are removed through a sieve to obtain small particles of modified MCA flame retardant particles.

[0013] Furthermore, the MCA flame retardant particles obtained after screening in step 2) are 1-4 μm.

[0014] Furthermore, the antioxidant is at least one of antioxidant 1098, antioxidant 1010, and antioxidant 168.

[0015] Based on the same inventive concept, the present invention provides a method for preparing high and low temperature resistant cyclic flame retardant V0 PA66, which comprises the following steps:

[0016] (1) Take PA66 according to the amount and dry it at 100-110°C for 4-6 hours;

[0017] (2) taking PA12 and antioxidant in proportion, and mixing them with nylon 66 at high speed in a high-speed mixer;

[0018] (3) The mixed material in step (2) is added to a twin-screw extruder through the main feed port of the twin-screw extruder, and calcium stearate and a flame retardant are added from the side feed port during melt extrusion, mixed and plasticized, melt extruded, and the extruded material is cooled, air-dried, pelletized, and dried to obtain a glass fiber reinforced flame-retardant nylon energy storage connector special material.

[0019] Furthermore, the temperature setting range of the twin-screw extruder in step (3) is 235-270° C., the screw speed is 200-500 rpm, and the vacuum degree is -0.6-1.0 Kgf / cm2.

[0020] Further, the temperature of each zone of the twin-screw extruder is:

[0021] Zone 1 temperature: 245-250°C;

[0022] Zone 2 temperature: 265-270°C;

[0023] Temperature in zone 3: 265-270°C;

[0024] Temperature in zone 4: 270-265°C;

[0025] Zone 5 temperature: 265-260°C;

[0026] Temperature of zone 6: 260~255℃;

[0027] Temperature of zone 7: 255~250℃;

[0028] Zone 8 temperature: 240-245°C;

[0029] Temperature in zone 9: 235-240°C;

[0030] Zone 10 temperature: 255~250℃;

[0031] Machine head temperature: 260~265℃.

[0032] Based on the same inventive concept, the present invention also applies the MAC flame retardant treated with a silane coupling agent to the preparation of PA66 resin.

[0033] The beneficial effects achieved by the present invention are:

[0034] The MAC flame retardant prepared by the semi-dry method (urea method) after being treated with a silane coupling agent can make the interface connection between the MAC flame retardant and the nylon 66 matrix more firmly through the bridging effect of the coupling agent in the nylon 66 system, and can be more evenly dispersed in the nylon matrix resin, which can not only reduce the agglomeration effect in the nylon resin, but also avoid the stress concentration fracture at the agglomeration point caused by agglomeration, so that the material is more likely to crack at the agglomeration point when it is impacted by an external force; and through experimental comparison, it can also achieve a better flame retardant effect with a smaller addition amount, and a small addition amount can reduce the influence of the flame retardant on the mechanical properties of the material, especially the low-temperature toughness, so that the matrix material can maintain a better low-temperature toughness and have better high and low temperature cycle resistance.

[0035] The invention adds PA12 with a long carbon chain to PA66, which can not only increase the fluidity of PA66, but also increase its low-temperature toughness when dispersed in PA66; and forms a uniform sea-island system with the MAC flame retardant modified by a silane coupling agent uniformly dispersed in the PA66 matrix, thereby further improving the toughness of PA66. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Unless otherwise specified, the equipment, reagents or raw materials used in the following examples are all commercially available.

[0038] Example 1: In this Example 1, PA66 plastic was prepared according to the material ratio in Table 1 and the relevant properties were characterized.

[0039] Table 1: Proportions of materials in Examples and Comparative Examples

[0040]

[0041] The raw materials used in Table 1 above are:

[0042] PA66 was purchased from Shenma EPR27 of China Shenma Industrial Co., Ltd.;

[0043] PA12 is 3030JI9L PA12 purchased from Dongguan Jinshixiang Plastic Raw Materials Co., Ltd.

[0044] Wet-process MCA and semi-dry-process MCA were purchased from Shanghai Better Chemical Co., Ltd., which were MAC flame retardants prepared by the cyanuric acid method and urea method (two-step method).

[0045] The antioxidant 1098 was purchased from BASF, Germany.

[0046] Calcium stearate purchased from Jiangxi Hongyuan Chemical Co., Ltd.

[0047] The silane coupling agent used was silane coupling agent KH570, which was purchased from Shandong Yousuo Chemical Technology Co., Ltd.

[0048] The treated semi-dry MCA, i.e., the MCA flame retardant treated with a silane coupling agent, has the following specific steps for treatment:

[0049] 1) Take the MCA flame retardant (dry MAC flame retardant) prepared by the urea method, and spray the silane coupling agent evenly onto the melamine cyanurate in a spraying manner while stirring;

[0050] 2) After being placed for 2-3 hours and dried naturally, the mixture is crushed by an ultrasonic vibration screen, and oversized particles are removed by a sieve to obtain modified MCA flame retardant particles with a particle size of 1-4 μm.

[0051] The mechanical properties of PA66 prepared according to the embodiments and comparative examples in Table 1 were tested, and the results are shown in Table 2.

[0052] Table 2: Performance test table

[0053]

[0054] Testing conditions: tensile strength, test condition 50mm / min; flexural strength, test condition 5mm / min; flame retardancy, test condition 1.6mm; elongation, test condition 50mm / min; cantilever beam notched impact, test condition 23℃ / 5.5kj;

[0055] It can be seen from the above table that the MAC flame retardant prepared by the semi-dry method (urea method) after treatment with a silane coupling agent has more excellent mechanical properties in the nylon 66 system, especially low-temperature toughness, which can enable the base material to maintain good low-temperature toughness and better high and low temperature cycle resistance; and through experimental comparison, it can also achieve a better flame retardant effect with a smaller addition amount, and a small addition amount can reduce the influence of the flame retardant on the mechanical properties of the material.

[0056] Adding PA12 with a long carbon chain to PA66 can not only increase the fluidity of PA66, but also disperse in PA66, which helps to increase its low-temperature toughness.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high and low temperature resistant cyclic flame retardant V0 PA66, characterized in that: It is made of the following raw materials in parts by weight:

2. The high and low temperature cycle resistant flame retardant V0 PA66 according to claim 1, characterized in that: The MCA flame retardant is modified by a silane coupling agent.

3. The high and low temperature cycle resistant flame retardant V0 PA66 according to claim 2, characterized in that: The silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

4. A high and low temperature resistant cycle flame retardant V0 PA66 according to claim 2 or 3, characterized in that: The operation of treating the MCA flame retardant with a silane coupling agent comprises the following steps: 1) taking the MCA flame retardant prepared by the urea method, spraying the silane coupling agent onto the melamine cyanurate in a spraying manner while stirring; 2) After drying, the particles are treated with an ultrasonic vibration screen and oversized particles are removed through a sieve to obtain small particles of modified MCA flame retardant particles.

5. The high and low temperature cycle resistant flame retardant V0 PA66 according to claim 4, characterized in that: The MCA flame retardant particles obtained after screening in step 2) are 1-4 μm.

6. The high and low temperature cycle resistant flame retardant V0 PA66 according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1098, antioxidant 1010, and antioxidant 168.

7. Use of the high and low temperature cycle resistant flame retardant V0 PA66 according to any one of claims 1 to 6 in the preparation of engineering plastics for terminals.

8. The method for preparing a high and low temperature resistant cyclic flame retardant V0 PA66 according to any one of claims 1 to 6, characterized in that: It includes the following steps: (1) Take PA66 according to the amount and dry it at 100-110°C for 4-6 hours; (2) taking PA12 and antioxidant in proportion, and mixing them with nylon 66 at high speed in a high-speed mixer; (3) The mixed material in step (2) is added to a twin-screw extruder through the main feed port of the twin-screw extruder, and calcium stearate and a flame retardant are added from the side feed port during melt extrusion, mixed and plasticized, melt extruded, and the extruded material is cooled, air-dried, pelletized, and dried to obtain a glass fiber reinforced flame-retardant nylon energy storage connector special material.

9. The method for preparing a high and low temperature resistant cyclic flame retardant V0 PA66 according to claim 8, characterized in that: The temperature setting range of the twin-screw extruder in step (3) is 235-270° C., the screw speed is 200-500 rpm, and the vacuum degree is -0.6-1.0 Kgf / cm2.

10. Use of the MAC flame retardant according to claim 2 or 3 in the preparation of PA66 resin.

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