A high-toughness, flame-retardant nylon composite material resistant to red phosphorus precipitation and its preparation method

Abstract

This invention discloses a high-toughness, red phosphorus-resistant flame-retardant nylon composite material, comprising the following raw materials by weight percentage: 39-47% nylon resin, 23-27% glass fiber, 12-16% phosphorus-based flame retardant, 2.0-4.0% flame retardant synergist, 1.0-3% acid absorber, and 8.0-15% toughening agent. This material possesses high mechanical strength while meeting high toughness requirements, and also exhibits flame retardant and low acid exudation properties.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a high-toughness, flame-retardant nylon composite material resistant to red phosphorus precipitation and its preparation method. Background Technology

[0002] Red phosphorus flame-retardant nylon is widely used in new energy vehicles, low-voltage electrical appliances, electronic appliances, and home appliances due to its high cost-effectiveness. However, this material also has some drawbacks, especially the tendency for acid precipitation to occur when stored in a humid and hot environment for a long time, causing the product surface to turn white. This acid-precipitated white substance is mostly phosphate, which is easily soluble in water and acidic, thus affecting the appearance and function of the product. Therefore, the research on inhibiting and controlling acid precipitation of red phosphorus materials is a key research direction for red phosphorus flame-retardant nylon materials.

[0003] Currently, injection-molded metal inserts for electronic and electrical applications require coating materials with high flame retardancy, insulation, and low corrosion resistance. Therefore, red phosphorus materials are required to have low acid precipitation. Furthermore, some heavier metal inserts also require drop testing, necessitating materials that meet certain mechanical and flame retardant properties while also possessing high toughness (notched impact > 17 KJ / m). 2 Red phosphorus flame-retardant nylon materials are relatively mature in the field of metal insert injection molding, mainly some conventionally modified red phosphorus flame-retardant nylon materials (notched impact strength 8~12KJ / m). 2 However, meeting the high toughness requirements is relatively difficult. Currently, there are very few reports in this technical field in China. Patent CN113527877A discloses a high CTI value black red phosphorus flame-retardant reinforced nylon 66 and its preparation method. This product achieves high CTI performance by introducing highly thermally conductive materials and water-containing hydroxides into the PA66 matrix, but its overall suspended impact resistance is relatively low. Patent CN104017354A discloses a halogen-free high-toughness red phosphorus flame-retardant nylon for manufacturing explosion-proof equipment and its preparation method. This product mainly achieves high toughness by adding toughening agents to PA66 / PA6 resin, exhibiting high impact resistance but relatively low overall mechanical strength. Therefore, overcoming the shortcomings of existing technologies and developing a high-toughness, red phosphorus-resistant flame-retardant nylon composite material has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to develop a high-toughness, red phosphorus-resistant flame-retardant nylon composite material. This invention uses PA66 and a long-chain carbon nylon alloy as the base resin, adds specially coated red phosphorus flame-retardant masterbatch, introduces flame-retardant synergists, acid absorbers, toughening agents, and processing aids, and combines this with a special extrusion processing method to develop a high-toughness, red phosphorus-resistant flame-retardant nylon composite material. This material possesses high mechanical strength while meeting high toughness requirements, and also exhibits flame-retardant and low acid exudation properties.

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

[0006] A high-toughness, red phosphorus-resistant flame-retardant nylon composite material, comprising the following raw materials by weight percentage:

[0007] Nylon resin 39~47%

[0008] Fiberglass 23-27%

[0009] Phosphorus-based flame retardants 12-16%

[0010] Flame retardant synergist 2.0~4.0%

[0011] Acid absorbent 1.0~3%

[0012] Toughening agent 8.0~15%.

[0013] The nylon resin includes ordinary nylon and long-chain nylon. The ordinary nylon is PA66 and / or PA6; the long-chain nylon is one or more of PA610, PA612, PA1012, and PA1212. The ratio of long-chain nylon to ordinary nylon is more than 1 / 5 to significantly improve acid precipitation performance. Too high a ratio is uneconomical, while too low a ratio does not significantly improve low precipitation performance.

[0014] The glass fiber is a hydrolysis-resistant short glass fiber, preferably Chongqing International ECS301HP.

[0015] The red phosphorus flame retardant masterbatch is a customized product. It is a red phosphorus masterbatch with PA6 as the carrier and processed by a special coating process. The phosphorus content is 50%, and it is specifically the Xinde FR9980 flame retardant.

[0016] The flame retardant synergist is one or more of silicate, zinc borate, and zinc stannate, preferably a combination of silicate and zinc stannate, with a preferred ratio of 7:3.

[0017] The acid absorbent is composed of one or more of nano-sized magnesium oxide, nano-sized zinc oxide, and nano-sized montmorillonite, preferably a compound of nano-sized magnesium oxide, nano-sized zinc oxide, and nano-sized montmorillonite, with a preferred ratio of 5:4:1.

[0018] The toughening agent is a blend of maleic anhydride grafted with POE / EPDM, which has a high grafting rate and good compatibility with PA substrate and glass fiber.

[0019] The high-toughness, red phosphorus-resistant flame-retardant nylon composite material may further contain the following raw materials by weight percentage:

[0020] Lubricant 0.4~0.6%

[0021] Antioxidant 0.2~0.4%

[0022] Coupling agent 0.1-0.3%

[0023] Black masterbatch 2.0-3.0%.

[0024] The lubricant mentioned is silicone masterbatch.

[0025] The antioxidant is a compound of a high-temperature resistant phosphite antioxidant and a hindered phenolic antioxidant.

[0026] The coupling agent is silane coupling agent KH550.

[0027] The black masterbatch mentioned above is a carbon black masterbatch with PA6 as the carrier.

[0028] A method for preparing a high-toughness, red phosphorus-resistant flame-retardant nylon composite material, comprising the following steps:

[0029] Step 1: First, stir the nylon resin, toughening agent and silane coupling agent evenly at 40 rpm, then add the flame retardant synergist, acid absorber, lubricant and antioxidant and stir evenly at 25 rpm to obtain the mixture.

[0030] Step 2: A twin-screw extruder with dual-side feeding and loss-in-weight feeding is used. There are two side feed ports, mainly for hydrolysis-resistant short glass fibers and red phosphorus flame retardants, located in zones 5 and 7 respectively. The screw speed is set to 300 rpm, and the process temperature is set according to the processing temperature of nylon resin. High-toughness, red phosphorus-resistant flame-retardant nylon composite material can be obtained by extrusion granulation.

[0031] Compared with the prior art, the advantages of the present invention are as follows:

[0032] The innovation of this invention lies in the addition of long-chain carbon nylon to PA66 resin to reduce water absorption, the addition of specially coated red phosphorus flame-retardant masterbatch, and the introduction of flame-retardant synergists, acid scavengers, maleic anhydride-grafted POE / PDME toughening agents, and processing aids. These are combined with a double-sided feeding extrusion process to synergistically prepare a red phosphorus flame-retardant nylon composite material. This material possesses high mechanical strength while meeting high toughness requirements, and also exhibits flame retardant and low acid exudation properties. Implementation

[0033] The technical solution of the present invention will be further described below with reference to specific comparative examples 1-2 and embodiments 1-13.

[0034] The raw materials and proportions used in this invention are shown in Table 1, but are not limited to the raw materials and proportions used in the comparative examples and embodiments.

[0035] The raw materials were premixed with high-speed stirring according to the proportions in Table 1, and granulated using a twin-screw extrusion method with double-sided feeding and multiple loss-of-weight weighing to obtain a high-toughness, flame-retardant nylon composite material resistant to red phosphorus precipitation.

[0036] Performance characterization and testing methods:

[0037] The tensile strength of the composite materials prepared in the above comparative examples and embodiments was measured using a universal testing machine in accordance with GB / T 1040.2-2022 standard; the flexural strength was measured using a universal testing machine in accordance with GB / T 9341-2008 standard; the notched impact strength was measured using a simply supported beam impact testing machine in accordance with GB / T 1043.1-2008 standard; the vertical combustion flame retardancy was measured using a vertical-horizontal combustion meter in accordance with GB / T 2408-2008 standard; the total phosphorus was measured using a spectrophotometer in accordance with GB / T 11893 standard; the injection molding pH3 was measured using a phosphine tester in accordance with the enterprise standard; and the precipitation from boiling water was judged visually.

[0038] The raw material ratios and performance test results of Comparative Examples 1 and 2 are shown in Table 2. Comparative Examples 1 and 2 are commercially available red phosphorus flame-retardant nylon materials, Comparative Example 1 is a normal red phosphorus flame-retardant reinforced nylon material, and Comparative Example 2 is a red phosphorus flame-retardant reinforced and toughened nylon material. Their total phosphorus and phosphine release are relatively high, and there is obvious precipitation after boiling in water.

[0039] The raw material ratios and performance test results of Examples 1-13 are shown in Table 2. Through continuous optimization of the raw materials, the total phosphorus and phosphine release of the material are significantly reduced, and there is no precipitation phenomenon after boiling in water. In addition, through the synergistic effect of the formula, the toughness of the material is also greatly improved, and the vertical burning of 1.6mm meets the V-0 requirements.

[0040] Compared to Comparative Example 2, Example 2 introduces long-chain nylon PA612 into the material, which effectively reduces the water absorption rate of the material. This can reduce the effect of water on the red phosphorus flame retardant to a certain extent, thereby improving the acid precipitation performance of the material.

[0041] Examples 3 and 4, based on Example 2, respectively introduced hydrolysis-resistant glass fiber and a high-grafting-rate toughening agent, significantly improving the bonding between the material and the nylon substrate and red phosphorus flame retardant, thereby enhancing the material's mechanical and impact properties. The notched impact strength was increased from 14 kJ / m. 2 Increased to 19 kJ / m 2 Meanwhile, the hydrolysis-resistant glass fiber helps protect against the precipitation of red phosphoric acid. When the feeding method of the red phosphorus flame retardant was changed, the total phosphorus and phosphine release from the material decreased significantly. This is because the side-feeding method of the red phosphorus flame retardant effectively reduces the shearing effect of the screw assembly on the red phosphorus. However, considering Examples 1-5, precipitation still occurs when the material is boiled in water, mainly due to the influence of zinc borate.

[0042] Examples 8-11 use a silicate synergist combined with zinc stannate to replace zinc borate, and introduce an acid scavenger, which effectively improves the water boiling precipitation performance of the material, while further reducing the release of total phosphorus and phosphine. However, the increased amount of filler minerals affects the mechanical and impact properties of the material.

[0043] Examples 12-13 further demonstrate how increasing the toughening agent content can improve the impact performance of materials. When the toughening agent content is 10%, the notched impact strength can reach 21 kJ / m. 2 Meanwhile, the mechanical properties and flame retardant of the material meet the requirements. When the toughening agent content is further increased, the notched impact strength of the composite material is improved, but the processing performance of the material is significantly affected.

[0044] The formulation and performance test results are shown in Tables 1 and 2.

[0045] raw materials Comparison 1 Comparison 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Shenma PA66 EPR27 45% 36% 40% 36% 36% 36% 36% 35.75% 35.75% 35.75% 33.75% 33.75% 33.75% 31.75% 29.75% Polymerized cis PA6 2.45 10% 10% / / / / / / / / / / / / / Shandong Guangyin PA612 / / 6% 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% Taishan short fiber T435N 25% 25% 25% 25% / / / / / / / / / / / 301HP chopped glass fiber / / / / 25% 25% 25% 25% 25% 25% 25% 25% 25% 25% 25% Silane coupling agent KH550 / / / / / / / 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% Red Phosphorus 50 (Customized) Main Feed 14% 14% 14% 14% 14% 14% / / / / / / / / / Red Phosphorus 50 (Customized) Side Feeding / / / / / 14% 14% 14% 14% 14% 14% 14% 14% 14% Silicate synergist / / / / / / / / 2.1% 2.1% 2.1% 2.1% 2.1% 2.1% 2.1% Zinc stannate / / / / / / / / / 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% Zinc borate 3% 3% 3% 3% 3% 3% 3% 3% 0.9% / / / / / 310B toughening agent / / / / / 9% 9% 9% 9% 9% 9% 9% 9% 11% 13% KT-915B toughening agent / 9% 9% 9% 9% / / / / / / / / / / Nanoscale magnesium oxide / / / / / / / / / / 2% / / / / Nano-sized magnesium oxide: nano-sized zinc oxide (ratio 1:1) / / / / / / / / / / / 2% / / / Nano-sized magnesium oxide: nano-sized zinc oxide: nano-sized montmorillonite (ratio 5:4:1) / / / / / / / / / / / / 2% 2% 2% Silicone Masterbatch 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 1010 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 9228 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% Carbon black masterbatch 1044 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2%

[0046] Table 2 Test Performance Results

[0047] raw materials Comparison 1 Comparison 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Tensile strength (MPa) 143 120 119 118 124 121 124 127 127 122 120 121 129 119 113 Bending strength (MPa) 218 176 175 174 183 179 185 189 189 181 182 180 187 178 171 <![CDATA[Notched impact of simply supported beam (KJ / m 2 )]]> 9.5 14 14 15 17 19 18 20 20 19 18 18 19 21 22 Vertical burning (1.6mm) V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 Vertical burning (0.8mm) V-0 Non-flame retardant Non-flame retardant Non-flame retardant Non-flame retardant Non-flame retardant V-1 V-1 V-1 V-1 V-1 V-1 V-0 V-1 Non-flame retardant Total phosphorus 7d (mg / L) 17 13 12 8.2 7.1 7.0 3.4 3.4 3.5 2.5 2.5 2.4 1.9 1.7 1.6 Injection molding pH 3 (ppm) 13.5 11.8 10.0 8.6 7.5 7.6 4.7 4.9 4.9 3.4 3.1 3.0 2.5 2.2 2.3 Boiling in water to extract the extract (2 hours) Significant precipitation Significant precipitation Significant precipitation Small amount of precipitation Small amount of precipitation Small amount of precipitation Small amount of precipitation Small amount of precipitation Very small amount of precipitation No precipitation No precipitation No precipitation No precipitation No precipitation No precipitation

[0048] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A high-toughness, red phosphorus-resistant flame-retardant nylon composite material, comprising the following raw materials by weight percentage: Nylon resin 39~47% Fiberglass 23-27% Phosphorus-based flame retardants 12-16% Flame retardant synergist 2.0~4.0% Acid absorbent 1.0~3% Toughening agent 8.0~15%; The nylon resin includes ordinary nylon and long-chain nylon, wherein the ordinary nylon is PA66 and / or PA6; the long-chain nylon is one or more of PA610, PA612, PA1012, and PA1212, wherein the ratio of long-chain nylon to ordinary nylon is more than 1 / 5. The phosphorus-based flame retardant mentioned is Xinde FR9980 flame retardant; The flame retardant synergist is a compound of silicate and zinc stannate; The acid absorbent is a compound of nano-sized magnesium oxide, nano-sized zinc oxide, and nano-sized montmorillonite in a ratio of 5:4:

1. The toughening agent is 310B.

2. A high-toughness, red phosphorus-resistant flame-retardant nylon composite material, comprising the following raw materials by mass percentage: PA66 grade is ERP27 33.75% PA612 is manufactured by Shandong Guangyin (10%). The fiberglass grade is 301HP 25%. Coupling agent KH550 0.25% The manufacturer and brand of the phosphorus-based flame retardant is Xinde FR9980 14%. Silicate synergist 2.1% Zinc stannate 0.9% The toughening agent grade is 310B 9%. A 2% compound of nano-sized magnesium oxide, nano-sized zinc oxide, and nano-sized montmorillonite in a 5:4:1 ratio. Silicone masterbatch 0.5% Antioxidant 1010 0.1% Antioxidant 9228 0.2% Carbon black masterbatch 1044 2.2%.

3. The high-toughness, red phosphorus-resistant flame-retardant nylon composite material according to claim 1, characterized in that, The glass fiber is a hydrolysis-resistant short glass fiber.

4. The high-toughness, red phosphorus-resistant flame-retardant nylon composite material according to claim 1, characterized in that, The high-toughness, red phosphorus-resistant flame-retardant nylon composite material may further contain the following raw materials by weight percentage: Lubricant 0.4~0.6% Antioxidant 0.2~0.4% Coupling agent 0.1-0.3% Black masterbatch 2.0-3.0%.

5. The high-toughness, red phosphorus-resistant flame-retardant nylon composite material according to claim 4, characterized in that, The lubricant is a silicone masterbatch; the antioxidant is a compound of a high-temperature resistant phosphite antioxidant and a hindered phenolic antioxidant; the coupling agent is a silane coupling agent KH550; and the black masterbatch is a carbon black masterbatch with PA6 as the carrier.