Flame retardant as well as preparation method and application thereof

Abstract

The invention relates to a flame retardant and a preparation method and application thereof, and relates to the technical field of flame retardants, the preparation method of the flame retardant comprises the following steps: adding hypophosphite, polyethylene glycol and a silane coupling agent into water, and stirring to obtain a first mixture; performing pulsed electric field treatment on the first mixture to obtain a second mixture; and filtering the second mixture, and washing and drying the obtained solid product to obtain the flame retardant. According to the invention, a material system composed of hypophosphite, polyethylene glycol and a silane coupling agent is modified by adopting a pulsed electric field technology, so that the physical properties such as particle size distribution and particle regularity of hypophosphite are remarkably improved, and the compatibility and flame-retardant effect of hypophosphite and a high polymer material are also improved; the defects of the existing hypophosphite flame retardant are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of flame retardants, and in particular to a flame retardant and a preparation method and application thereof. Background Art

[0002] Flame retardants, as core additives to improve the fire safety performance of various materials, play a pivotal role in a wide range of fields such as plastics, rubber, textiles and building materials. Traditionally, hypophosphite flame retardants have won wide recognition and favor in the market due to their high flame retardant performance and environmental protection characteristics. However, in the actual application process, this type of flame retardant has gradually revealed some limitations that cannot be ignored.

[0003] Specifically, the particle sizes of hypophosphite flame retardants such as aluminum hypophosphite prepared by current processes are generally distributed in the range of 30 to 50 microns. The particle size is relatively large, and the shape is often irregular, and the particle size distribution range is also relatively wide. This particle size characteristic means that in actual use, it is necessary to rely on mechanical processing processes such as mechanical crushing or air flow crushing to further refine aluminum hypophosphite to less than 10 microns to meet the needs of polymer material processing. This process not only increases the difficulty and cost of production, but also during the crushing process, due to the violent collision and friction between particles, sparks are easily generated and even cause danger, which brings potential risks to production safety.

[0004] More importantly, the compatibility problem between hypophosphite flame retardants such as aluminum hypophosphite and polymer materials is also particularly prominent. Due to the weak interfacial bonding force between the two and poor dispersibility. This not only affects the uniform distribution of the flame retardant in the material, but also weakens its flame retardant effect. What is more serious is that even if the amount of aluminum hypophosphite added is relatively small, due to its uneven dispersion and poor compatibility, it will still have a significant impact on the physical properties of polymer materials. For example, key indicators such as impact strength and elongation at break will drop significantly, which seriously limits the further application and promotion of aluminum hypophosphite flame retardants in the field of polymer materials. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a flame retardant and a preparation method and application thereof.

[0006] In a first aspect, the present invention provides a method for preparing a flame retardant, the method for preparing the flame retardant comprising the following steps:

[0007] Adding hypophosphite, polyethylene glycol and a silane coupling agent into water and stirring to obtain a first mixture;

[0008] Subjecting the first mixture to a pulse electric field treatment to obtain a second mixture;

[0009] The second mixed material is filtered, and then the obtained solid product is washed and dried to obtain the flame retardant.

[0010] Furthermore, the weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is (10-15):(1-5):(0.5-1):(20-30).

[0011] Furthermore, the weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is 13:2:0.7:25.

[0012] Furthermore, the step of subjecting the first mixture to pulse electric field treatment to obtain the second mixture comprises the following process:

[0013] The electrodes of the pulse electric field device are placed in the first mixture, the electrode spacing is set to 15-25 mm, the pulse power supply constant voltage is 3-6 V and the pulse period is 4-8 ms, and then the pulse electric field device is turned on for pulse electric field treatment for 300-500 seconds to obtain the second mixture.

[0014] Furthermore, the constant voltage of the pulse power supply is 4.5V, and the duration of the pulse electric field treatment is 420 seconds.

[0015] Further, the hypophosphite includes aluminum hypophosphite, the polyethylene glycol includes at least one of polyethylene glycol 500 and polyethylene glycol 600, and the silane coupling agent includes γ-aminopropyltriethoxysilane.

[0016] In a second aspect, the present invention provides a flame retardant, which is prepared by the preparation method described in any one of the first aspects.

[0017] In a third aspect, the present invention provides use of the flame retardant described in any one of the second aspects in the preparation of a flame retardant material.

[0018] In a fourth aspect, the present invention provides a flame retardant material, which comprises the following raw materials in parts by weight:

[0019] 95-110 parts of a resin base material and 10-20 parts of the flame retardant according to any one of the second aspects;

[0020] The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of (11-15):(0.5-1) by oxygen-enriched microwave plasma.

[0021] Furthermore, the method for preparing the flame retardant material comprises the following steps:

[0022] The polyketone resin and the epoxy resin are placed in a microwave plasma treatment instrument, oxygen and argon with a volume ratio of 8:1 are introduced as working media, and glow discharge treatment is performed for 60 to 120 seconds under the conditions of microwave power of 200 to 400 W and air intake of 60 to 80 mL / min, and then oxygen is continuously introduced for 5 to 15 minutes to obtain a resin base material;

[0023] The resin base material and the flame retardant are mixed evenly to obtain a mixture;

[0024] The mixed material is placed in a twin-screw machine for melt blending to obtain the flame retardant material.

[0025] The above technical solution provided by the present invention has at least the following advantages compared with the prior art:

[0026] The present invention provides a flame retardant and a preparation method and application thereof. The present invention uses pulsed electric field technology to modify a material system consisting of hypophosphite, polyethylene glycol and a silane coupling agent, which not only significantly improves the physical properties of hypophosphite such as particle size distribution and particle regularity, but also improves the compatibility of hypophosphite with polymer materials and the flame retardant effect, thus making up for the shortcomings of existing hypophosphite flame retardants. Specifically:

[0027] Under the action of the pulse electric field, through the instantaneous high voltage and short-time electric field, a strong physical and chemical effect is produced on the material system, inducing polarization in the material system, enhancing the interaction between molecules, and helping to form a more regular and compact particle structure, improving the regularity of the particles, and improving the particle size distribution of hypophosphite to make it more uniform, which helps the flame retardant to be evenly distributed in the polymer material and improve the flame retardant effect. At the same time, polyethylene glycol and silane coupling agent can be more evenly combined on the surface of hypophosphite particles under the action of the electric field to achieve chemical modification, thereby improving its compatibility and promoting the close combination between the flame retardant and the polymer material. In addition, the addition of silane coupling agent can also form a chemical bond between the polymer material and the flame retardant, further enhancing the interfacial bonding between the two, making it difficult for the flame retardant to fall off or migrate during long-term use, and improving the durability of the flame retardant effect.

[0028] In summary, the present invention modifies the material system composed of hypophosphite, polyethylene glycol and silane coupling agent through pulse electric field technology, which not only significantly improves the physical properties of hypophosphite, but also improves the compatibility and flame retardant effect of the flame retardant with polymer materials through the synergistic mechanism between the components, thereby making up for the shortcomings of existing hypophosphite flame retardants. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0031] In a first aspect, the present invention provides a method for preparing a flame retardant, the method for preparing the flame retardant comprising the following steps:

[0032] Adding hypophosphite, polyethylene glycol and a silane coupling agent into water and stirring to obtain a first mixture;

[0033] Subjecting the first mixture to a pulse electric field treatment to obtain a second mixture;

[0034] The second mixed material is filtered, and then the obtained solid product is washed and dried to obtain the flame retardant.

[0035] The present invention uses pulsed electric field technology to modify the material system composed of hypophosphite, polyethylene glycol and silane coupling agent, which not only significantly improves the physical properties of hypophosphite such as particle size distribution and particle regularity, but also improves the compatibility of hypophosphite with polymer materials and the flame retardant effect, making up for the shortcomings of existing hypophosphite flame retardants. Specifically:

[0036] Under the action of the pulse electric field, through the instantaneous high voltage and short-time electric field, a strong physical and chemical effect is produced on the material system, inducing polarization in the material system, enhancing the interaction between molecules, and helping to form a more regular and compact particle structure, improving the regularity of the particles, and improving the particle size distribution of hypophosphite to make it more uniform, which helps the flame retardant to be evenly distributed in the polymer material and improve the flame retardant effect. At the same time, polyethylene glycol and silane coupling agent can be more evenly combined on the surface of hypophosphite particles under the action of the electric field to achieve chemical modification, thereby improving its compatibility and promoting the close combination between the flame retardant and the polymer material. In addition, the addition of silane coupling agent can also form a chemical bond between the polymer material and the flame retardant, further enhancing the interfacial bonding between the two, making it difficult for the flame retardant to fall off or migrate during long-term use, and improving the durability of the flame retardant effect.

[0037] In summary, the present invention modifies the material system composed of hypophosphite, polyethylene glycol and silane coupling agent through pulse electric field technology, which not only significantly improves the physical properties of hypophosphite, but also improves the compatibility and flame retardant effect of the flame retardant with polymer materials through the synergistic mechanism between the components, thereby making up for the shortcomings of existing hypophosphite flame retardants.

[0038] In some specific embodiments, the hypophosphite can be directly purchased from the market as a product model HT-220 (particle size (D50) 15-20 μm).

[0039] In some specific embodiments, the weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is (10-15):(1-5):(0.5-1):(20-30).

[0040] In some specific embodiments, the weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is 13:2:0.7:25.

[0041] In some specific embodiments, the step of subjecting the first mixture to pulse electric field treatment to obtain the second mixture comprises the following process:

[0042] The electrodes of the pulse electric field device are placed in the first mixture, the electrode spacing is set to 15-25 mm, the pulse power supply constant voltage is 3-6 V and the pulse period is 4-8 ms, and then the pulse electric field device is turned on for pulse electric field treatment for 300-500 seconds to obtain the second mixture.

[0043] In some specific embodiments, the constant voltage of the pulse power supply is 4.5V, and the duration of the pulse electric field treatment is 420 seconds.

[0044] In some specific embodiments, the hypophosphite includes aluminum hypophosphite, the polyethylene glycol includes at least one of polyethylene glycol 500 and polyethylene glycol 600, and the silane coupling agent includes γ-aminopropyltriethoxysilane.

[0045] In a second aspect, based on the same inventive concept, the present invention provides a flame retardant, which is prepared by the preparation method described in any one of the first aspects.

[0046] In a third aspect, based on the same inventive concept, the present invention provides the use of the flame retardant described in any one of the second aspects in the preparation of flame retardant materials.

[0047] In a fourth aspect, based on the same inventive concept, the present invention provides a flame retardant material, which comprises the following raw materials in parts by weight:

[0048] 95-110 parts of a resin base material and 10-20 parts of the flame retardant according to any one of the second aspects;

[0049] The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of (11-15):(0.5-1) by oxygen-enriched microwave plasma.

[0050] The present invention uses polyketone resin and epoxy resin in an appropriate ratio as the resin base material system, and uses oxygen-enriched microwave plasma treatment to improve the compatibility between the resin base material systems and increase the oxygen-containing group content of the polymer resin structure itself, thereby further improving the compatibility with hypophosphite flame retardants such as aluminum hypophosphite and the flame retardant effect of the resulting flame retardant material.

[0051] In some specific embodiments, the polyketone resin can be directly used as commercially available products such as product models POK M630F, POKM330A, etc.

[0052] In some specific embodiments, the epoxy resin can be directly selected from commercially available products such as product models E-51, E-44, etc.

[0053] In some specific embodiments, the method for preparing the flame retardant material comprises the following steps:

[0054] The polyketone resin and the epoxy resin are placed in a microwave plasma treatment instrument, oxygen and argon with a volume ratio of 8:1 are introduced as working media, and glow discharge treatment is performed for 60 to 120 seconds under the conditions of microwave power of 200 to 400 W and air intake of 60 to 80 mL / min, and then oxygen is continuously introduced for 5 to 15 minutes to obtain a resin base material;

[0055] The resin base material and the flame retardant are mixed evenly to obtain a mixture;

[0056] The mixed material is placed in a twin-screw machine for melt blending to obtain the flame retardant material.

[0057] In some specific embodiments, the working condition parameters of the twin-screw extruder include: a feeding speed of 150 to 260 rpm, the screw temperatures of each section of the twin-screw extruder from the feeding port to the die are: zone 1 155 to 165°C, zone 2 185 to 200°C, zone 3 185 to 200°C, zone 4 185 to 200°C, zone 5 185 to 200°C, die temperature 200 to 210°C, main engine speed 200 to 400 rpm, and a vacuum degree lower than 0.1 MPa.

[0058] It should be noted that, for the flame retardant provided by the present invention, and the components and raw materials involved in the preparation method and application thereof, unless otherwise specified or explained, each component can be directly made from commercially available products or can be prepared in-house according to the preparation method disclosed in the prior art; the operation steps involved, unless otherwise specified or explained, can be carried out in accordance with the operation method disclosed in the prior art or using existing equipment according to its method of use.

[0059] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0060] Example 1

[0061] This example provides a flame retardant, and the preparation method of the flame retardant comprises the following steps:

[0062] Step (1): adding aluminum hypophosphite with a particle size (D50) of 15 to 20 μm, polyethylene glycol 500 and γ-aminopropyltriethoxysilane into water and stirring, wherein the weight ratio of the aluminum hypophosphite, the polyethylene glycol 500, the γ-aminopropyltriethoxysilane and the water is 13:2:0.7:25, to obtain a first mixed material;

[0063] Step (2): placing the electrodes of the pulse electric field device in the first mixed material obtained in step (1), setting the electrode spacing to 20 mm, the pulse power supply constant voltage to 4.5 V, and the pulse period to 5 ms, then turning on the pulse electric field device to perform pulse electric field treatment for 420 seconds to obtain the second mixed material;

[0064] Step (3): filtering the second mixed material obtained in step (2), and then washing and drying the obtained solid product to obtain the flame retardant.

[0065] Example 2

[0066] This example provides a flame retardant, and the preparation method of the flame retardant comprises the following steps:

[0067] Step (1): adding aluminum hypophosphite with a particle size (D50) of 15 to 20 μm, polyethylene glycol 600 and γ-aminopropyltriethoxysilane into water and stirring, wherein the weight ratio of the aluminum hypophosphite, the polyethylene glycol 600, the γ-aminopropyltriethoxysilane and the water is 10:1:0.5:20, to obtain a first mixed material;

[0068] Step (2): placing the electrodes of the pulse electric field device in the first mixed material obtained in step (1), setting the electrode spacing to 15 mm, the pulse power supply constant voltage to 3 V, and the pulse period to 4 ms, then turning on the pulse electric field device to perform pulse electric field treatment for 500 seconds to obtain the second mixed material;

[0069] Step (3): filtering the second mixed material obtained in step (2), and then washing and drying the obtained solid product to obtain the flame retardant.

[0070] Example 3

[0071] This example provides a flame retardant, and the preparation method of the flame retardant comprises the following steps:

[0072] Step (1): adding aluminum hypophosphite with a particle size (D50) of 15 to 20 μm, polyethylene glycol 600 and γ-aminopropyltriethoxysilane into water and stirring, wherein the weight ratio of the aluminum hypophosphite, the polyethylene glycol 600, the γ-aminopropyltriethoxysilane and the water is 15:5:1:30, to obtain a first mixed material;

[0073] Step (2): placing the electrodes of the pulse electric field device in the first mixed material obtained in step (1), setting the electrode spacing to 25 mm, the pulse power supply constant voltage to 6 V, and the pulse period to 8 ms, then turning on the pulse electric field device to perform pulse electric field treatment for 300 seconds to obtain the second mixed material;

[0074] Step (3): filtering the second mixed material obtained in step (2), and then washing and drying the obtained solid product to obtain the flame retardant.

[0075] Example 4

[0076] This example provides a flame retardant material, which includes the following raw materials in parts by weight:

[0077] 100 parts of resin base material and 15 parts of the flame retardant obtained in Example 1;

[0078] The resin base material is polyketone resin.

[0079] The method for preparing the flame retardant material comprises the following steps:

[0080] Step (1): uniformly mixing the resin base material and the flame retardant to obtain a mixture;

[0081] Step (2): placing the mixture obtained in step (1) in a twin-screw machine for melt blending to obtain the flame retardant material.

[0082] Example 5

[0083] This example provides a flame retardant material, which includes the following raw materials in parts by weight:

[0084] 100 parts of resin base material and 15 parts of the flame retardant obtained in Example 1;

[0085] The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of 13:0.8 through oxygen-enriched microwave plasma.

[0086] The method for preparing the flame retardant material comprises the following steps:

[0087] Step (1): placing a polyketone resin and an epoxy resin in a microwave plasma treatment apparatus, introducing oxygen and argon in a volume ratio of 8:1 as a working medium, performing glow discharge treatment for 90 seconds under the conditions of a microwave power of 320 W and an air intake of 70 mL / min, and then continuing to introduce oxygen for 10 minutes to obtain a resin base material;

[0088] Step (2): uniformly mixing the resin base material and the flame retardant to obtain a mixture;

[0089] Step (3): placing the mixture obtained in step (2) in a twin-screw machine for melt blending to obtain the flame retardant material.

[0090] Example 6

[0091] This example provides a flame retardant material, which includes the following raw materials in parts by weight:

[0092] 95 parts of resin base material and 10 parts of the flame retardant obtained in Example 2;

[0093] The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of 11:0.5 through oxygen-enriched microwave plasma.

[0094] The method for preparing the flame retardant material comprises the following steps:

[0095] Step (1): placing a polyketone resin and an epoxy resin in a microwave plasma treatment apparatus, introducing oxygen and argon in a volume ratio of 8:1 as a working medium, performing glow discharge treatment for 120 seconds under the conditions of a microwave power of 200 W and an air intake of 80 mL / min, and then continuing to introduce oxygen for 10 minutes to obtain a resin base material;

[0096] Step (2): uniformly mixing the resin base material and the flame retardant to obtain a mixture;

[0097] Step (3): placing the mixture obtained in step (2) in a twin-screw machine for melt blending to obtain the flame retardant material.

[0098] Example 7

[0099] This example provides a flame retardant material, which includes the following raw materials in parts by weight:

[0100] 110 parts of resin base material and 20 parts of the flame retardant obtained in Example 3;

[0101] The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of 15:1 through oxygen-enriched microwave plasma.

[0102] The method for preparing the flame retardant material comprises the following steps:

[0103] Step (1): placing a polyketone resin and an epoxy resin in a microwave plasma treatment instrument, introducing oxygen and argon in a volume ratio of 8:1 as a working medium, performing glow discharge treatment for 60 seconds under the conditions of a microwave power of 400 W and an air intake of 60 mL / min, and then continuing to introduce oxygen for 10 minutes to obtain a resin base material;

[0104] Step (2): uniformly mixing the resin base material and the flame retardant to obtain a mixture;

[0105] Step (3): placing the mixture obtained in step (2) in a twin-screw machine for melt blending to obtain the flame retardant material.

[0106] Comparative Example 1

[0107] This example provides a flame retardant, which is aluminum hypophosphite with a particle size (D50) of 15 to 20 μm (that is, the aluminum hypophosphite raw material in Example 1).

[0108] Comparative Example 2

[0109] This example provides a flame retardant and a preparation method thereof, which differs from Example 1 only in that the constant voltage of the pulse power supply in step (2) is adjusted to 10V; the remaining steps and parameters are the same.

[0110] Comparative Example 3

[0111] This example provides a flame retardant material and a preparation method thereof, which is different from Example 4 only in that the flame retardant used is aluminum hypophosphite with a particle size (D50) of 15 to 20 μm provided in Comparative Example 1.

[0112] Test Example 1

[0113] In this example, the flame retardants provided in Examples 1 to 3 and Comparative Examples 1 to 2 were tested for particle size distribution and particle sphericity with reference to the test methods disclosed in the prior art, and the test results are shown in Table 1. Among them, the particle size distribution was tested according to ISO13320-2020 Particle size analysis-Laser diffraction methods; the sphericity was tested according to GB / T37406-2019 Sphericity detection method for spherical silica powder for electronic packaging by particle dynamic photoelectric projection method. The closer the sphericity is to 1, the higher the particle regularity.

[0114] Table 1

[0115] Test samples Particle size distribution D90 / D10 Particle sphericity Example 1 4.98 1.39 Example 2 5.62 1.50 Example 3 5.80 1.71 Comparative Example 1 11.75 3.27 Comparative Example 2 7.16 2.54

[0116] As shown in Table 1, compared with Comparative Examples 1 to 2, the particle size distribution of the flame retardant provided by the embodiment of the present invention is narrower and the particle regularity is higher, which indicates that the present invention can significantly improve the particle size distribution and particle regularity of the hypophosphite flame retardant by treating the hypophosphite with a pulse electric field under appropriate voltage parameters.

[0117] Test Example 2

[0118] In this example, the flame retardant properties of the flame retardant materials obtained in Examples 4 to 7 and Comparative Example 3 were tested with reference to the test method disclosed in the prior art, and the test results are shown in Table 2. The limiting oxygen index was tested with reference to the ISO4589-2:2017 standard.

[0119] Table 2

[0120] Test samples Limiting oxygen index (%) Example 4 32.9 Example 5 43.1 Example 6 37.4 Example 7 40.5 Comparative Example 3 23.7

[0121] It can be seen from Table 2 that, compared with Comparative Example 3, the limiting oxygen index of the flame retardant material provided by the embodiment of the present invention is higher, and the limiting oxygen index of the flame retardant material provided by Example 5 can reach up to 43.1%.

[0122] In summary, the present invention provides a flame retardant and a preparation method and application thereof. The present invention uses pulse electric field technology to modify the material system composed of hypophosphite, polyethylene glycol and silane coupling agent, which not only significantly improves the physical properties of hypophosphite such as particle size distribution and particle regularity, but also improves the compatibility of hypophosphite with polymer materials and the flame retardant effect, thereby making up for the shortcomings of existing hypophosphite flame retardants.

[0123] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0124] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a flame retardant, characterized in that: The preparation method of the flame retardant comprises the following steps: Adding hypophosphite, polyethylene glycol and a silane coupling agent into water and stirring to obtain a first mixture; Subjecting the first mixture to a pulse electric field treatment to obtain a second mixture; The second mixed material is filtered, and then the obtained solid product is washed and dried to obtain the flame retardant.

2. The method for preparing a flame retardant according to claim 1, characterized in that: The weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is (10-15):(1-5):(0.5-1):(20-30).

3. The method for preparing a flame retardant according to claim 1, characterized in that: The weight ratio of the hypophosphite, the polyethylene glycol, the silane coupling agent and the water is 13:2:0.7:

25.

4. The method for preparing a flame retardant according to claim 1, characterized in that: The step of subjecting the first mixture to pulse electric field treatment to obtain a second mixture comprises the following process: The electrodes of the pulse electric field device are placed in the first mixture, the electrode spacing is set to 15-25 mm, the pulse power supply constant voltage is 3-6 V and the pulse period is 4-8 ms, and then the pulse electric field device is turned on for pulse electric field treatment for 300-500 seconds to obtain the second mixture.

5. The method for preparing a flame retardant according to claim 4, characterized in that: The constant voltage of the pulse power supply is 4.5V, and the duration of the pulse electric field treatment is 420 seconds.

6. The method for preparing a flame retardant according to claim 1, characterized in that: The hypophosphite includes aluminum hypophosphite, the polyethylene glycol includes at least one of polyethylene glycol 500 and polyethylene glycol 600, and the silane coupling agent includes γ-aminopropyltriethoxysilane.

7. A flame retardant, characterized in that: The flame retardant is prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the flame retardant according to claim 7 in the preparation of flame retardant materials.

9. A flame retardant material, characterized in that: The flame retardant material comprises the following raw materials in parts by weight: 95-110 parts of a resin base material and 10-20 parts of the flame retardant according to claim 7; The resin base material is obtained by treating polyketone resin and epoxy resin in a weight ratio of (11-15):(0.5-1) by oxygen-enriched microwave plasma.

10. The flame retardant material according to claim 9, characterized in that: The method for preparing the flame retardant material comprises the following steps: The polyketone resin and the epoxy resin are placed in a microwave plasma treatment instrument, oxygen and argon with a volume ratio of 8:1 are introduced as working media, and glow discharge treatment is performed for 60 to 120 seconds under the conditions of microwave power of 200 to 400 W and air intake of 60 to 80 mL / min, and then oxygen is continuously introduced for 5 to 15 minutes to obtain a resin base material; The resin base material and the flame retardant are mixed evenly to obtain a mixture; The mixed material is placed in a twin-screw machine for melt blending to obtain the flame retardant material.