High-toughness flame-retardant PA66 composite material for connector and preparation method thereof

Abstract

The invention discloses a high-toughness flame-retardant PA66 composite material for a connector and a preparation method of the high-toughness flame-retardant PA66 composite material. The preparation method comprises the following steps: uniformly mixing the first elastomer, the second elastomer, maleic anhydride powder, the initiator and the antioxidant to obtain a first composition; uniformly mixing BPS powder, organic silicon resin, stearate and a flame-retardant synergist to obtain a second composition; the first composition is put into an internal mixer for internal mixing, then the second composition is put into the internal mixer in batches for continuous internal mixing, and finally the obtained internal mixing product is fed into a screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant master batch; uniformly mixing the PA66, the BPS / organic silicon flame retardant master batch, the lubricant and the antioxidant, then feeding the mixture into a double-screw extruder, and performing extrusion and granulation to obtain the high-toughness flame-retardant PA66 composite material. According to the invention, the flame retardant property of the PA66 composite material is improved, and the addition amount of BPS in a flame retardant system is effectively reduced.

Description

Technical Field

[0001] The invention relates to a PA66 composite material, and in particular to a high-toughness flame-retardant PA66 composite material for connectors and a preparation method thereof. Background Art

[0002] Connectors, also known as connectors, are mainly used for connections between circuits. They are the core basic components necessary for electrical connections in circuit systems and are widely used in smart homes, automobiles, communications, computers and peripherals, industry, military and aerospace. At present, the materials used for connectors are mainly brominated flame-retardant PA66 materials containing decabromodiphenylethane (DBDPE). DBDPE has poor stability and certain toxicity. There is a risk of being banned in the future. Therefore, a new alternative material is urgently needed for brominated flame-retardant PA66 materials for connectors.

[0003] Chinese patent CN116102881B discloses a bromine-based flame-retardant polyamide composite material and its preparation method and application. The material includes components: 36-52 parts of aliphatic polyamide; 6-18 parts of aromatic polyamide; 15-50 parts of glass fiber; 17-30 parts of bromine / antimony flame retardant; the bromine / antimony flame retardant is a compound of brominated polystyrene (BPS) and antimony trioxide. However, this method has the disadvantages of high BPS addition, insufficient toughness of the composite material and low electrical tracking resistance. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing a high-toughness flame-retardant PA66 composite material for connectors, wherein BPS and silicone flame retardant are compounded into a composite masterbatch (with elastomer graft as the matrix) and introduced into the PA66 matrix, thereby improving the dispersion effect of the flame retardant, so that a good synergistic effect can be formed between the BPS flame retardant, silicone flame retardant, flame retardant synergist and resin matrix, thereby improving the flame retardant properties of the PA66 composite material and effectively reducing the amount of BPS added in the flame retardant system.

[0005] Another object of the present invention is to provide a high-toughness flame-retardant PA66 composite material for plug-ins.

[0006] Another object of the present invention is to provide a method for preparing a BPS / organic silicon flame retardant.

[0007] Another object of the present invention is to provide a BPS / organic silicon flame retardant.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention provides a method for preparing a high-toughness flame-retardant PA66 composite material for a connector, comprising the following steps:

[0010] (1) Preparation of BPS / silicone flame retardant masterbatch:

[0011] First, 35-62 parts of a first elastomer, 35-64 parts of a second elastomer, 0.5-2.5 parts of maleic anhydride powder, 0.1-0.3 parts of an initiator and 0.2-0.4 parts of an antioxidant are mixed uniformly to obtain a first composition, wherein the first elastomer is a styrene block copolymer; and the second elastomer is an ethylene-octene copolymer or ethylene propylene diene monomer rubber;

[0012] 40-70 parts of BPS powder, 20-39 parts of silicone resin, 0.5-1 parts of stearate, and 9-20.5 parts of flame retardant synergist are mixed to obtain a second composition;

[0013] 10-30 parts of the first composition are put into an internal mixer, and are internally mixed at 150-200° C. for 5-15 minutes. Then 70-90 parts of the second composition are put into the internal mixer in 3-5 times. After all the components are put into the internal mixer, the internal mixing is continued for 2-5 minutes. Finally, the obtained internal mixing product is sent to a single-screw or twin-screw extruder for extrusion and granulation to obtain a BPS / organic silicone flame retardant masterbatch.

[0014] (2) Preparation of high-toughness flame-retardant PA66 composite materials:

[0015] By weight, 59-74 parts of PA66, 25-40 parts of the BPS / silicone flame retardant masterbatch prepared in step (1), 0.2-0.8 parts of lubricant and 0.2-0.8 parts of antioxidant are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0016] Preferably, the styrene-based block copolymer is at least one of styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-propylene-styrene block copolymer (SEPS).

[0017] Preferably, the initiator in step (1) is one of diisopropylbenzene peroxide (DCP), 2,5-dimethyl-2,5-di-tert-butylhexane peroxide (DBPH), dibenzoyl peroxide (BPO), and diisopropyl di-tert-butyl peroxide (BIPB).

[0018] Preferably, the antioxidant in step (1) is at least one of antioxidant BHT, antioxidant 1010, antioxidant 1098, antioxidant 245, antioxidant 1076, antioxidant AO-20, antioxidant 3391, antioxidant 445, antioxidant H3336, antioxidant HS02, antioxidant 168, and antioxidant PEPQ.

[0019] Preferably, the organic silicone resin in step (1) is one of methyl silicone resin, ethyl silicone resin, vinylphenyl silicone resin, isopropyl silicone resin, phenyl silicone resin, methylphenyl silicone resin, vinylphenyl silicone resin, and phosphorus-containing methylphenyl silicone resin.

[0020] Preferably, the stearate in step (1) is at least one of calcium stearate, zinc stearate, magnesium stearate, barium stearate, sodium stearate and lithium stearate; and the flame retardant synergist in step (1) is at least one of zinc borate, antimony trioxide, antimony pentoxide and sodium antimonate.

[0021] Preferably, the lubricant in step (2) is at least one of OP wax, E wax, rice bran wax, silicone powder, ethylene bisstearamide and pentaerythritol stearate; the antioxidant in step (2) is at least one of antioxidant BHT, antioxidant 1010, antioxidant 1098, antioxidant 245, antioxidant 1076, antioxidant AO-20, antioxidant 3391, antioxidant 445, antioxidant H3336, antioxidant HS02, antioxidant 168 and antioxidant PEPQ.

[0022] The present invention also provides a high-toughness flame-retardant PA66 composite material for connectors, which is prepared by the preparation method of the high-toughness flame-retardant PA66 composite material for connectors.

[0023] The present invention also provides a method for preparing a BPS / organic silicon flame retardant, comprising the following steps:

[0024] First, 35-62 parts of a first elastomer, 35-64 parts of a second elastomer, 0.5-2.5 parts of maleic anhydride powder, 0.1-0.3 parts of an initiator and 0.2-0.4 parts of an antioxidant are mixed uniformly to obtain a first composition, wherein the first elastomer is a styrene block copolymer; and the second elastomer is an ethylene-octene copolymer or ethylene propylene diene monomer rubber;

[0025] 40-70 parts of BPS powder, 20-39 parts of silicone resin, 0.5-1 parts of stearate, and 9-20.5 parts of flame retardant synergist are mixed to obtain a second composition;

[0026] 10-30 parts of the first composition are put into an internal mixer and mixed at 150-200°C for 5-15 minutes. Then 70-90 parts of the second composition are put into the internal mixer in 3-5 times. After all the composition is put into the internal mixer, the mixing is continued for 2-5 minutes. Finally, the obtained mixed product is sent to a single-screw or twin-screw extruder for extrusion and granulation to obtain BPS / silicone flame retardant masterbatch.

[0027] The present invention also provides a BPS / organic silicon flame retardant, which is prepared by the preparation method of the BPS / organic silicon flame retardant.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] (1) The preparation method of the high-toughness flame-retardant PA66 composite material for connectors of the present invention, BPS and silicone resin are compounded into a masterbatch and introduced into the PA66 matrix, which can effectively improve the dispersing effect of BPS. This is because after the styrene-based block copolymer matrix is ​​grafted with maleic anhydride, BPS is coated in the masterbatch preparation process, and then it can act as a bridge between BPS and PA66 in the blending process, which significantly improves the dispersing effect of BPS, can reduce the amount of flame retardant added to a certain extent, and maintain a good flame retardant effect.

[0030] (2) The method for preparing the high-toughness flame-retardant PA66 composite material for connectors of the present invention comprises compounding and grafting POE or EPDM with a styrene-based block copolymer and introducing the resultant as a matrix of a flame-retardant masterbatch into a PA66 composite material system, which can effectively reduce the crystallinity of PA66 and significantly improve the toughness of the composite material.

[0031] (3) The preparation method of the high-toughness flame-retardant PA66 composite material for connectors of the present invention, in the preparation of BPS / organic silicone flame retardant masterbatch, can make the metal ions carried by the stearate react with the matrix graft to form an ionomer by coordination complex reaction, further form ion clusters in the material, and cause ion cross-linking. When subjected to external force impact, the stress inside the material is dispersed by the formed cross-linking network, and the impact strength is enhanced, which can further effectively improve the rheological properties and impact properties of the flame-retardant PA66 composite material system.

[0032] (4) The method for preparing the high-toughness flame-retardant PA66 composite material for connectors of the present invention, in the preparation of BPS / organic silicone flame retardant masterbatch, the silicone resin and the flame retardant synergists such as zinc borate, antimony trioxide, antimony pentoxide, sodium antimonate, etc. work together to have an anti-dripping effect and can effectively reduce the amount of BPS used, further can reduce costs and reduce the generation of odorous gases due to decomposition of BPS flame retardants during the production and processing process, and at the same time can improve the tracking resistance index (CTI) of the composite material, which can simultaneously meet the requirements of low bromine content and high CTI for brominated flame retardant PA66.

[0033] (5) The high-toughness flame-retardant PA66 composite material for connectors of the present invention has the characteristics of high fluidity, easy processing, low temperature resistance, excellent impact resistance, etc., and has high application value in various connectors. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0035] Example 1

[0036] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of phosphorus-containing methyl phenyl silicone resin, 0.6 parts of zinc stearate and 16.4 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 80 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0037] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of rice bran wax and 0.5 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0038] Example 2

[0039] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 35 parts of SEBS, 64 parts of POE, 0.5 parts of maleic anhydride powder, 0.1 parts of DBPH initiator and 0.4 parts of antioxidant 1098 were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of methyl silicone resin, 0.6 parts of aluminum stearate and 16.4 parts of zinc borate were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 150°C for 15 minutes, and then 80 parts of composition 2 were put into the mixer in 3 times, and after all the ingredients were put in, the mixing was continued for 5 minutes. Finally, the obtained mixed product was sent to a twin-screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0040] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of OP wax and 0.5 parts of antioxidant (1098 and 168 in a ratio of 3:2) were put into a mixer for initial mixing, and then the initial mixture was sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0041] Example 3

[0042] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 62 parts of SEBS, 35 parts of POE, 2.5 parts of maleic anhydride powder, 0.3 parts of BPO initiator and 0.2 parts of antioxidant 1076 were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of methylphenyl silicone resin, 0.6 parts of calcium stearate and 16.4 parts of sodium antimonate were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 200°C for 5 minutes, and then 80 parts of composition 2 were put into the mixer in 5 times, and after all the ingredients were put in, the mixing was continued for 2 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0043] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / silicone flame retardant masterbatch prepared in step (1), 0.5 parts of ethylene bisstearamide and 0.5 parts of antioxidant (1010 and 168 in a ratio of 3:2) were put into a mixer for initial mixing, and then the initial mixture was sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0044] Example 4

[0045] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 70 parts of BPS powder, 20 parts of phosphorus-containing methyl phenyl silicone resin, 1 part of zinc stearate and 9 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 80 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0046] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of rice bran wax and 0.5 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0047] Example 5

[0048] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 40 parts of BPS powder, 39 parts of phosphorus-containing methyl phenyl silicone resin, 0.5 parts of zinc stearate and 20.5 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 80 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0049] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of rice bran wax and 0.5 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0050] Example 6

[0051] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of phosphorus-containing methyl phenyl silicone resin, 0.6 parts of zinc stearate and 16.4 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 10 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 90 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0052] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of rice bran wax and 0.5 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0053] Example 7

[0054] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of phosphorus-containing methyl phenyl silicone resin, 0.6 parts of zinc stearate and 16.4 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 30 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 70 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0055] (2) Preparation of high-toughness flame-retardant PA66 composite material. 64 parts of PA66, 35 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.5 parts of rice bran wax and 0.5 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0056] Example 8

[0057] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of phosphorus-containing methyl phenyl silicone resin, 0.6 parts of zinc stearate and 16.4 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 80 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0058] (2) Preparation of high-toughness flame-retardant PA66 composite material. 74 parts of PA66, 25 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.8 parts of rice bran wax and 0.2 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0059] Example 9

[0060] (1) Preparation of BPS / organic silicon flame retardant masterbatch. First, 49 parts of SEBS, 49 parts of POE, 1.5 parts of maleic anhydride powder, 0.2 parts of DCP initiator and 0.3 parts of antioxidant (antioxidant 1010 and 168 ratio 2:1) were put into a mixer and mixed evenly to obtain composition 1, and then 60 parts of BPS powder, 23 parts of phosphorus-containing methyl phenyl silicone resin, 0.6 parts of zinc stearate and 16.4 parts of antimony trioxide were put into a mixer and mixed evenly to obtain composition 2. After the initial mixing was completed, 20 parts of composition 1 were put into a mixer and mixed at 185°C for 8 minutes, and then 80 parts of composition 2 were put into the mixer in 4 times, and after all the ingredients were put in, the mixing was continued for 3 minutes. Finally, the obtained mixed product was sent to a single screw extruder for extrusion and granulation to obtain BPS / organic silicon flame retardant masterbatch.

[0061] (2) Preparation of high-toughness flame-retardant PA66 composite material. 59 parts of PA66, 40 parts of BPS / organic silicone flame retardant masterbatch prepared in step (1), 0.2 parts of rice bran wax and 0.8 parts of antioxidant (1098 and PEPQ ratio is 3:2) are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

[0062] Comparative Example 1

[0063] Compared with Example 1, 49 parts of SEBS and 49 parts of POE are replaced by 98 parts of POE.

[0064] Comparative Example 2

[0065] Compared to Example 1, no stearate is added to Composition 2.

[0066] Comparative Example 3

[0067] Compared with Example 1, no silicone resin is added to Composition 2.

[0068] Comparative Example 4

[0069] The materials and additives used in Example 1, such as PA66, SEBS, POE and BPS, are all put into a mixer according to the corresponding proportions in Example 1 and mixed evenly. Then the primary mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a flame-retardant PA66 composite material.

[0070] Comparative Example 5

[0071] Except for SEBS, POE elastomer and maleic anhydride powder, all other materials and additives used in Example 1 are put into a mixer according to the corresponding proportions of Example 1 and mixed evenly. Then, the primary mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a flame-retardant PA66 composite material.

[0072] Material testing methods

[0073] Flame retardant performance: tested according to UL94 test standard;

[0074] CTI: Tested according to IEC60112 test standard;

[0075] Impact performance: The notched impact strength of the simply supported beam was tested according to ISO 179-1.

[0076] All test specimens were prepared by an injection molding machine and tested after conditioning for 28 hours in a standard environment with a relative humidity of 50±5% and a temperature of 23±2°C. The test results are shown in Table 1.

[0077] Table 1 Performance test results of flame retardant PA66 composite materials prepared in Examples and Comparative Examples

[0078] Test items Flame retardant properties CTI / V <![CDATA[Notched impact strength / kJ·m -2 > Example 1 0.8mm V-0 350 12.5 Example 2 1.6mm V-0 350 12.7 Example 3 0.8mm V-0 350 12.0 Example 4 0.8mm V-0 325 11.0 Example 5 1.6mm V-0 350 11.2 Example 6 0.8mm V-0 350 9.2 Example 7 1.6mm V-0 325 15.2 Example 8 3.2mm V-0 300 9.7 Example 9 0.8mm V-0 350 13.3 Comparative Example 1 1.6mm V-0 325 11.4 Comparative Example 2 0.8mm V-0 350 12.1 Comparative Example 3 1.6mm V-0 250 12.6 Comparative Example 4 3.2mm V-1 325 8.9 Comparative Example 5 3.2mm V-1 325 4.9

[0079] Table 1 shows the performance test results of the flame retardant PA66 composite materials prepared in various embodiments and comparative examples. From the comparison of the test results of embodiments 1-9 and comparative examples 1-5 in the table, it can be seen that the flame retardant PA66 composite materials prepared in the present invention have excellent flame retardant properties, impact properties and tracking resistance, can fully meet the requirements of DBDPE flame retardant PA66 composite materials for replacement, low bromine content and high CTI performance, and have high application value in various connectors.

[0080] From the comparison between Examples 1-3 and Comparative Example 1, it can be seen that elastomer 1 performs better in improving the dispersion of BPS, and elastomer 2 performs better in improving the toughness of the composite material system (impact resistance, the higher the impact strength, the better the toughness), but when only one elastomer is added, the overall performance decreases significantly; from the comparison between Example 1 and Comparative Example 2, it can be seen that the introduction of stearate can improve the impact performance of the composite material system to a certain extent; from the comparison between Examples 1, 4-5 and Comparative Example 3, it can be seen that the introduction of silicone can significantly reduce the addition amount of BPS and effectively improve the CTI performance of the composite material system; from Example 1 From the comparison of Examples 1 and 6-7, it can be seen that under the same addition amount, the higher the content of the flame retardant component in the BPS / silicone flame retardant masterbatch, the better the flame retardant effect and CTI effect, and the lower the toughness. However, when the CTI is increased to a certain value, it no longer increases with the increase of the content; from the comparison of Examples 1 and 8-9, it can be seen that with the increase of the addition amount of the BPS / silicone flame retardant masterbatch, the flame retardant performance, impact performance and tracking resistance are also significantly improved; from the comparison of Example 1 and Comparative Examples 4-5, it can be seen that the flame retardant and the elastomer are combined in the form of a masterbatch and then introduced into the PA66 composite material system by the present invention, which has obvious comprehensive performance advantages.

[0081] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-toughness flame-retardant PA66 composite material for connectors, characterized in that: The following steps are involved: (1) Preparation of BPS / silicone flame retardant masterbatch: First, 35-62 parts of a first elastomer, 35-64 parts of a second elastomer, 0.5-2.5 parts of maleic anhydride powder, 0.1-0.3 parts of an initiator and 0.2-0.4 parts of an antioxidant are mixed uniformly to obtain a first composition, wherein the first elastomer is a styrene block copolymer; and the second elastomer is an ethylene-octene copolymer or ethylene propylene diene monomer rubber; 40-70 parts of BPS powder, 20-39 parts of silicone resin, 0.5-1 parts of stearate, and 9-20.5 parts of flame retardant synergist are mixed to obtain a second composition; 10-30 parts of the first composition are put into an internal mixer, and are internally mixed at 150-200° C. for 5-15 minutes. Then 70-90 parts of the second composition are put into the internal mixer in 3-5 times. After all the components are put into the internal mixer, the internal mixing is continued for 2-5 minutes. Finally, the obtained internal mixing product is sent to a single-screw or twin-screw extruder for extrusion and granulation to obtain a BPS / organic silicone flame retardant masterbatch. (2) Preparation of high-toughness flame-retardant PA66 composite materials: By weight, 59-74 parts of PA66, 25-40 parts of the BPS / silicone flame retardant masterbatch prepared in step (1), 0.2-0.8 parts of lubricant and 0.2-0.8 parts of antioxidant are put into a mixer for initial mixing, and then the initial mixture is sent to a twin-screw extruder for extrusion and granulation to obtain a high-toughness flame-retardant PA66 composite material.

2. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The styrene-based block copolymer is at least one of a styrene-butadiene-styrene block copolymer, a styrene-ethylene-butylene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, and a styrene-ethylene-propylene-styrene type block copolymer.

3. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The initiator in step (1) is one of diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di-tert-butylhexane peroxide, dibenzoyl peroxide, and di-tert-butyl diisopropylbenzene peroxide.

4. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The antioxidant in step (1) is at least one of antioxidant BHT, antioxidant 1010, antioxidant 1098, antioxidant 245, antioxidant 1076, antioxidant AO-20, antioxidant 3391, antioxidant 445, antioxidant H3336, antioxidant HS02, antioxidant 168, and antioxidant PEPQ.

5. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The organic silicone resin in step (1) is one of methyl silicone resin, ethyl silicone resin, vinylphenyl silicone resin, isopropyl silicone resin, phenyl silicone resin, methylphenyl silicone resin, vinylphenyl silicone resin, and phosphorus-containing methylphenyl silicone resin.

6. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The stearate in step (1) is at least one of calcium stearate, zinc stearate, magnesium stearate, barium stearate, sodium stearate and lithium stearate; the flame retardant synergist in step (1) is at least one of zinc borate, antimony trioxide, antimony pentoxide and sodium antimonate.

7. The method for preparing the high-toughness flame-retardant PA66 composite material for connectors according to claim 1, characterized in that: The lubricant in step (2) is at least one of OP wax, E wax, rice bran wax, silicone powder, ethylene bisstearamide and pentaerythritol stearate; the antioxidant in step (2) is at least one of antioxidant BHT, antioxidant 1010, antioxidant 1098, antioxidant 245, antioxidant 1076, antioxidant AO-20, antioxidant 3391, antioxidant 445, antioxidant H3336, antioxidant HS02, antioxidant 168 and antioxidant PEPQ.

8. A high-toughness flame-retardant PA66 composite material for connectors, characterized in that: The connector is prepared by the method for preparing the high-toughness flame-retardant PA66 composite material for connectors as described in any one of claims 1 to 7.

9. A method for preparing a BPS / organic silicon flame retardant, characterized in that: The following steps are involved: First, 35-62 parts of a first elastomer, 35-64 parts of a second elastomer, 0.5-2.5 parts of maleic anhydride powder, 0.1-0.3 parts of an initiator and 0.2-0.4 parts of an antioxidant are mixed uniformly to obtain a first composition, wherein the first elastomer is a styrene block copolymer; and the second elastomer is an ethylene-octene copolymer or ethylene propylene diene monomer rubber; 40-70 parts of BPS powder, 20-39 parts of silicone resin, 0.5-1 parts of stearate, and 9-20.5 parts of flame retardant synergist are mixed to obtain a second composition; 10-30 parts of the first composition are put into an internal mixer and mixed at 150-200°C for 5-15 minutes. Then 70-90 parts of the second composition are put into the internal mixer in 3-5 times. After all the composition is put into the internal mixer, the mixing is continued for 2-5 minutes. Finally, the obtained mixed product is sent to a single-screw or twin-screw extruder for extrusion and granulation to obtain BPS / silicone flame retardant masterbatch.

10. A BPS / organic silicon flame retardant, characterized in that: The composition is prepared by the preparation method of the BPS / organic silicon flame retardant according to claim 9.