High-flame-retardant material and preparation method thereof

Abstract

The invention belongs to the technical field of flame-retardant materials, and particularly relates to a high-flame-retardant material and a preparation method thereof. The preparation method comprises the following steps: reacting silanol with a flame retardant, then carrying out dealcoholization treatment, then carrying out mixing granulation with EVA and POE, and compounding the granulated material with glass fiber to obtain the high-flame-retardant material. The flame retardant comprises aluminum hydroxide. According to the preparation method, one end of silanol and one end of aluminum hydroxide are subjected to grafting reaction, and the flame retardant which can be coupled and contains more flame-retardant components is formed. After the flame retardant is subjected to dealcoholization treatment, the flame retardant is mixed with EVA and POE for granulation, the flame retardant performance can be effectively improved, and the non-dripping self-extinguishing state is achieved. EVA and POE are jointly used as base materials, so that the toughness, the flexibility and the workability of the material can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flame-retardant materials, and particularly relates to a high flame-retardant material and a preparation method thereof. BACKGROUND

[0002] With the increasing demand for fire safety in modern society, the research and development of high flame-retardant materials have become a hot topic in the field of material science. Although traditional flame-retardant materials can meet the fireproofing requirements to some extent, they often have poor mechanical properties, insufficient heat resistance, and poor environmental performance. For example, although bromine-based flame retardants have significant flame-retardant effects, their application is limited because they may release harmful gases during combustion. In recent years, researchers have been working to develop new high flame-retardant materials to overcome the shortcomings of traditional materials. For example, the invention patent with the publication number CN119081387A proposes a new flame-retardant material that combines a composite flame retardant with a thermoplastic polymer to achieve a balance between excellent flame-retardant performance and mechanical properties. This material not only exhibits good self-extinguishing properties during combustion, but also reduces environmental impact through the use of halogen-free flame retardants. However, despite the progress made by existing technologies, the stability of existing materials in high-temperature environments and their application in complex working conditions still face challenges. For example, traditional polypropylene materials often exhibit decreased toughness after improving flame-retardant performance. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a high flame-retardant material with good flame-retardant effect and toughness, and a preparation method thereof.

[0004] To solve the above technical problems, the technical solution adopted by the present application is as follows: a preparation method of a high flame-retardant material, comprising the following steps: reacting silanol with a flame retardant, then performing dealcoholization treatment, then mixing and granulating with EVA and POE, and then compounding the granulated material with glass fibers to obtain a high flame-retardant material; the flame retardant comprises aluminum hydroxide.

[0005] Another technical solution adopted by the present application is: a high flame-retardant material prepared by the above preparation method.

[0006] The high flame-retardant material of the present application has the following advantages: the preparation method of the high flame-retardant material grafts silanol and one end of aluminum hydroxide to form a flame retardant that can be coupled and has a higher content of flame-retardant components. After dealcoholization treatment of the flame retardant, mixing and granulation with EVA and POE can effectively improve the flame-retardant performance to achieve a non-dripping self-extinguishing state. EVA and POE together as a substrate can improve the toughness, softness, and easy processability of the material. DETAILED DESCRIPTION

[0007] To explain the technical content, achieved objectives and effects of the present invention in detail, the following describes them in conjunction with the implementation methods.

[0008] A method for preparing a highly flame-retardant material comprises the following steps: reacting silanol with a flame retardant, performing dealcoholization treatment, then mixing with EVA and POE to form granules, and compounding the granulated material with glass fiber to obtain the highly flame-retardant material; the flame retardant comprises aluminum hydroxide.

[0009] From the above description, it can be seen that the present invention reacts silanol with the flame retardant, and the hydroxyl groups in the silanol react with the hydroxyl groups on the surface of aluminum hydroxide to form a stable chemical bond, thereby achieving silanization treatment on the surface of aluminum hydroxide, which can increase the amount of aluminum hydroxide added to the substrate and effectively improve the flame retardant properties. Taking the condensation of a silanol hydroxyl group with a hydroxyl group on the surface of aluminum hydroxide as an example, the reaction equation is as follows:

[0010] In fact, multiple silanol hydroxyl groups may undergo condensation reactions with hydroxyl groups on the surface of aluminum hydroxide, and partial condensation reactions may also occur between silanol molecules to form oligomers.

[0011] The resulting reaction product is then mixed with EVA and POE and granulated. The shearing action of the screw evenly disperses the silanized aluminum hydroxide within the EVA and POE matrices, promoting interaction between the two. The resulting material exhibits the properties of an organic elastomer, exhibits excellent toughness, and is soft and easy to process. Simultaneously, the organic silanol chains physically entangle with the EVA molecular chains through intermolecular forces (such as van der Waals forces). This physical interaction strengthens the bonding between the aluminum hydroxide and the EVA, allowing for a more even dispersion of the aluminum hydroxide within the EVA matrix and increasing the amount of flame retardant that can be added, effectively enhancing flame retardancy and achieving a non-drip, self-extinguishing state.

[0012] Among them, POE can increase the toughness of the material and improve the bonding strength; glass fiber plays a skeleton and flame retardant role.

[0013] Furthermore, the preparation method of silanol includes the following steps: adding a silane coupling agent containing an epoxy group to an ethanol aqueous solution for reaction.

[0014] Furthermore, the reaction conditions of the ethanol aqueous solution and the epoxy group-containing silane coupling agent are: first heating to 40-60° C., and then adjusting the pH to 3-5 for reaction.

[0015] Furthermore, the reaction conditions of the ethanol aqueous solution and the epoxy group-containing silane coupling agent are: first heating to 40-60° C., then adjusting the pH to 3-5 and stirring for 15-30 minutes.

[0016] From the above description, we can see that the silane coupling agent containing epoxy groups undergoes hydrolysis under the action of water to generate silanol and methanol. The reaction equation is as follows:

[0017] Under certain conditions, the epoxy group of the silane coupling agent will react with some groups in EVA and POE (such as unsaturated bonds in EVA at high temperatures or in the presence of initiators, hydrogen bonds and chemical bonds between EVA and POE, etc.), further enhancing the interfacial bonding between the two.

[0018] Furthermore, the silane coupling agent containing epoxy group is KH-560.

[0019] As can be seen from the above description, the methoxy group (-OCH3) in the KH-560 molecule undergoes hydrolysis in the presence of water, generating silanol and methanol. KH-560 is prone to decomposition at high temperatures, so the reaction requires strict temperature and time control.

[0020] Furthermore, the flame retardant needs to be dried in advance before reacting with the silanol.

[0021] From the above description, it can be seen that the flame retardant is dried in advance before reacting with silanol to avoid the hydroxyl groups of water reacting with silanol and causing unnecessary material loss.

[0022] Furthermore, the flame retardant is dried at 80-110° C. for at least 5 hours.

[0023] Furthermore, the flame retardant also includes magnesium hydroxide.

[0024] As can be seen from the above description, the flame retardant using aluminum magnesium is more heat-resistant and has better flame retardant properties. The silanol hydroxyl groups condense with the hydroxyl groups on the surface of magnesium hydroxide to achieve silanization treatment on the surface of magnesium hydroxide, forming a flame retardant that can be coupled and has a higher content of flame retardant components.

[0025] Furthermore, the reaction temperature of the silanol and the flame retardant is 40-60°C.

[0026] Furthermore, the mass ratio of silanol to flame retardant is 1:2~4.

[0027] From the above description, it can be seen that the larger the proportion of flame retardant, the more complete the reaction of silanol can be ensured.

[0028] Furthermore, dealcoholization is achieved by filtration.

[0029] From the above description, it can be seen that granulation is convenient after dealcoholization treatment.

[0030] Furthermore, the dealcoholized material is first granulated and then mixed with EVA and POE for granulation.

[0031] From the above description, it can be seen that the material after dealcoholization treatment is first granulated and then mixed with EVA and POE for granulation, which can improve the uniformity of mixing of the components.

[0032] Furthermore, during mixed granulation, the mass ratio of the dealcoholized material, EVA and POE is 6~8:2:1.

[0033] Furthermore, the temperature during mixing and granulation is 120-160°C.

[0034] Furthermore, the mass ratio of the granulated material to the glass fiber is 2-3:1.

[0035] Another technical solution adopted by the present invention is: a highly flame-retardant material is prepared by the above-mentioned method for preparing highly flame-retardant material.

[0036] It can be seen from the above description that the flame retardant material of the present invention has good flame retardant properties and can achieve a self-extinguishing state without dripping.

[0037] Embodiment 1 of the present invention is: a method for preparing a highly flame-retardant material, comprising the following steps: S1: 10 g of KH-560 was added to 100 g of a 95 wt% ethanol aqueous solution and placed in a 50°C water bath. The pH was adjusted to 4 with acetic acid and stirred for 20 minutes to prepare a silanol. A 1:1 mass ratio of aluminum hydroxide and magnesium hydroxide was mixed and dried in a dehumidified dryer at 100°C for at least 5 hours to obtain a dry flame retardant.

[0038] S2: 110 g of silanol was mixed with 330 g of dry flame retardant and reacted at 50° C. for 5 h.

[0039] S3: Filter and dealcoholize the material obtained in S2.

[0040] S4: Granulating the material after dealcoholization treatment in S3.

[0041] S5: 70 g of the granulated material from S4, 20 g of EVA, and 10 g of POE were placed in a screw extruder and melt-blended at 140° C., and then mixed and granulated using an internal mixer.

[0042] S6: 200g of the granulated material from S5 was taken and compounded with 100g of glass fiber through a calendering device to obtain a highly flame retardant material.

[0043] Comparative Example 1 of the present invention is: The only difference between Comparative Example 1 and Example 1 is that the flame retardant is only aluminum hydroxide.

[0044] Comparative Example 2 of the present invention is: The only difference between Comparative Example 2 and Example 1 is that the flame retardant is only magnesium hydroxide.

[0045] Comparative Example 3 of the present invention is: The only difference between Comparative Example 3 and Example 1 is that the substrate only includes EVA.

[0046] Comparative Example 4 of the present invention is: The only difference between Comparative Example 4 and Example 1 is that the substrate only includes POE.

[0047] Comparative Example 5 of the present invention is: The only difference between Comparative Example 5 and Example 1 is that the silane coupling agent is not an epoxy-containing silane coupling agent, such as KH-602 (amino-based silane coupling agent).

[0048] The highly flame retardant materials prepared in Example 1 and Comparative Examples 1 to 5 were subjected to performance testing according to Section 8 of UL94-2023 Rev. 2-2024, wherein the toughness and softness judgment criteria were obtained through objective evaluation by 10 people. The test results are shown in Table 1.

[0049] Table 1

[0050] From the data in Table 1, we can see that: 1. Flame retardancy differences: Example 1, Comparative Example 3, and Comparative Example 4 were non-flammable; Comparative Examples 1, 2, and 5 were extinguished 3 seconds after removal from the flame, indicating that the flame retardancy of different cases was different, with some reaching the high non-flammability standard and some requiring a short time to extinguish after removal from the flame, indicating that the composite flame retardant and silane coupling agent can improve the flame retardancy.

[0051] 2. Toughness and Softness Performance: Example 1 and Comparative Examples 1, 2, and 5 all received an "Excellent" rating for toughness and softness; Comparative Examples 3 and 4 received an "Average" rating for both. This indicates that some materials exhibit excellent overall mechanical and tactile properties, while others exhibit poor toughness and softness. It is speculated that different formulations, processes, and other factors may result in different balances between flame retardancy and mechanical / tactile properties. For example, some materials may prioritize flame retardancy at the expense of toughness and softness, while others may maintain good toughness and softness while achieving flame retardancy (but not non-combustible grade).

[0052] The second embodiment of the present invention is a method for preparing a highly flame-retardant material, comprising the following steps: S1: 10 g of KH-560 was added to 100 g of a 95 wt% ethanol aqueous solution and placed in a 40°C water bath. The pH was adjusted to 3 with acetic acid and stirred for 15 minutes to prepare a silanol. A 1:1 mass ratio of aluminum hydroxide and magnesium hydroxide was mixed and dried in a dehumidified dryer at 80°C for at least 5 hours to obtain a dry flame retardant.

[0053] S2: 110 g of silanol was mixed with 220 g of dry flame retardant and reacted at 40° C. for 3 h.

[0054] S3: filtering and dealcoholizing the material obtained in S2.

[0055] S4: Granulating the material after dealcoholization treatment in S3.

[0056] S5: 80 g of the granulated material from S4, 20 g of EVA, and 10 g of POE were placed in a screw extruder and melt-blended at 120° C., and then mixed and granulated using an internal mixer.

[0057] S6: 300g of the granulated material from S5 was compounded with 100g of glass fiber through a calendering device to obtain a highly flame-retardant material.

[0058] The third embodiment of the present invention is a method for preparing a highly flame-retardant material, comprising the following steps: S1: 10 g of KH-560 was added to 100 g of a 95 wt% ethanol aqueous solution and placed in a 60°C water bath. The pH was adjusted to 5 with acetic acid and stirred for 30 minutes to prepare a silanol. A 1:1 mass ratio of aluminum hydroxide and magnesium hydroxide was mixed and dried in a dehumidified dryer at 110°C for at least 5 hours to obtain a dry flame retardant.

[0059] S2: 110 g of silanol was mixed with 440 g of dry flame retardant and reacted at 60° C. for 4 h.

[0060] S3: filtering and dealcoholizing the material obtained in S2.

[0061] S4: Granulating the material after dealcoholization treatment in S3.

[0062] S5: 60 g of the granulated material from S4, 20 g of EVA, and 10 g of POE were placed in a screw extruder and melt-blended at 160° C., and then mixed and granulated using an internal mixer.

[0063] S6: 250 g of the granulated material from S5 was compounded with 100 g of glass fiber through a calendering device to obtain a highly flame-retardant material.

[0064] The fourth embodiment of the present invention is: a highly flame-retardant material prepared by the preparation method of the first embodiment.

[0065] In summary, the highly flame retardant material and preparation method thereof provided by the present invention have the following advantages: 1. The hydroxyl groups in the silanol generated by hydrolysis react with the hydroxyl groups on the surface of aluminum hydroxide to form a stable chemical bond, thereby achieving silanization treatment on the surface of aluminum hydroxide, increasing the amount of aluminum hydroxide added to the substrate, and effectively improving the flame retardant properties.

[0066] 2. The silanol is prepared by KH-560, which can react with EVA and POE to enhance the interface bonding between them.

[0067] 3. The use of EVA and POE as the base material makes the material have high toughness and softness, and is easy to process.

[0068] 4. The flame-retardant material of the present application has the flame-retardant performance of not dripping and direct carbonization, and realizes non-combustion.

[0069] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent transformation made by the specification of the present application, or direct or indirect application in related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a highly flame retardant material, characterized in that: The following steps are involved: The silanol is reacted with the flame retardant and then dealcoholized, and then mixed with EVA and POE to form granules. The granulated material is compounded with glass fiber to obtain a highly flame retardant material; the flame retardant includes aluminum hydroxide.

2. The method for preparing a highly flame retardant material according to claim 1, wherein: The preparation method of the silanol comprises the following steps: adding a silane coupling agent containing an epoxy group into an ethanol aqueous solution to carry out a reaction.

3. The method for preparing a highly flame retardant material according to claim 1, wherein: The flame retardant needs to be dried in advance before reacting with the silanol.

4. The method for preparing a highly flame retardant material according to claim 1, wherein: The reaction temperature of the silanol and the flame retardant is 40-60°C.

5. The method for preparing a highly flame retardant material according to claim 1, wherein: The mass ratio of the silanol to the flame retardant is 1:2-4.

6. The method for preparing a highly flame retardant material according to claim 1, wherein: The dealcoholization is achieved by filtration.

7. The method for preparing a highly flame-retardant material according to claim 1, wherein: During the mixed granulation, the mass ratio of the dealcoholized material, EVA and POE is 6-8:2:

1.

8. The method for preparing a highly flame-retardant material according to claim 1, wherein: The temperature during the mixing and granulation is 120-160°C.

9. The method for preparing a highly flame-retardant material according to claim 1, wherein: The mass ratio of the granulated material to the glass fiber is 2-3:

1.

10. A highly flame retardant material prepared by the method for preparing a highly flame retardant material according to any one of claims 1 to 9.

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