Intumescent flame retardant, its preparation method and application

Abstract

The application discloses an intumescent flame retardant and a preparation method and application thereof. The intumescent flame retardant is a compound formed by ion bond of triazine compound and amino phosphonic acid. The amino phosphonic acid compound contains phosphorus element and nitrogen element, and the triazine compound is a kind of tertiary nitrogen structure, so that the combination of the two characteristics can obtain the "three source" integrated intumescent flame retardant, and the triazine compound can balance the phosphorus and nitrogen of the flame retardant. The triazine compound is combined by ion bond, and the obtained ionic flame retardant can be uniformly dispersed in the polymer. After the ionic flame retardant is dissolved or dispersed in the polymer material, the flame retardant performance of the triazine compound amino phosphonic acid salt is utilized, so that the efficient effect of flame retardation is achieved. The flame-retardant polypropylene uses the triazine compound as the flame retardant, so that the flame retardant has the advantages of small addition amount and good flame retardation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flame retardants, and particularly relates to an intumescent flame retardant and a preparation method and application thereof. BACKGROUND

[0002] The intumescent flame retardant has great application prospects in today's increasingly serious environmental problems due to its advantages of high efficiency and environmental protection, and more and more researchers and flame retardant manufacturers have carried out extensive and in-depth research on the development and preparation of high-performance intumescent flame retardants. Since the intumescent flame retardant is composed of an acid source, a carbon source and a gas source, the reasonable matching of the three sources is the key to the development and preparation of high-performance intumescent flame retardants. The traditional intumescent flame retardant is obtained by mixing and compounding the acid source, the carbon source and the gas source, and is usually obtained by mixing ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). The three components cannot be uniformly dispersed in the polymer matrix, so that the components cannot be well coordinated, which affects the flame retardant efficiency. In addition, the traditional intumescent flame retardant also has the problems of poor thermal stability and difficult processing.

[0003] It has been reported that the ionic flame retardant can be uniformly dispersed in the polymer. This flame retardant is also called "ionic solid flame retardant", which is a molecule or ion group composed of anions and cations. After dissolving or dispersing in the polymer material, it can interact with the polymer material to prevent combustion. However, the types of ionic flame retardants in the prior art are few and the flame retardant efficiency is low, so it is necessary to develop ionic flame retardants with high flame retardant efficiency. SUMMARY

[0004] In order to overcome the problems existing in the prior art, one of the purposes of the present application is to provide an intumescent flame retardant. The second purpose of the present application is to provide a preparation method of the intumescent flame retardant. The third purpose of the present application is to provide a flame-retardant polyolefin.

[0005] Amino phosphonic acid compounds are a class of compounds containing both phosphorus and nitrogen elements, which are very suitable for use in intumescent flame retardants. However, in general, the phosphorus content of this class of compounds is much higher than the nitrogen content, which is not conducive to achieving high-performance flame retardation due to the imbalance between phosphorus and nitrogen content. Triazine compounds are a class of compounds rich in tertiary nitrogen structures, which can be used as carbon sources and gas sources in intumescent flame retardants, and the nitrogen content of this class of compounds is high. Combining amino phosphonic acid compounds and triazine compounds can obtain an intumescent flame retardant with balanced phosphorus and nitrogen. Therefore, the present application combines the structural and physical advantages of amino phosphonic acid compounds and triazine compounds, combines amino phosphonic acid compounds and triazine compounds in the form of ionic bonds, and proposes a triazine-based compound for use as an intumescent flame retardant with "three sources" in one.

[0006] To achieve the above object, the technical scheme adopted by the present application is:

[0007] The present application provides an intumescent flame retardant, which is a compound formed by ionically bonding a triazine compound and an aminophosphonic acid.

[0008] Preferably, the molar ratio of the triazine compound to the aminophosphonic acid is (0.5-3):1.

[0009] More preferably, the molar ratio of the triazine compound to the aminophosphonic acid is (0.75-2):1.

[0010] Preferably, the aminophosphonic acid has the following structural formulae 1-6:

[0011]

[0012] Preferably, the triazine compound has the following structural formulae a or b:

[0013]

[0014] wherein R1 and R2 are independently selected from one of amino, nitrogen-containing aliphatic heterocyclic group, nitrogen-containing aromatic heterocyclic group, alicyclic group amino, aryl amino aliphatic amino; X is alkanediamine group.

[0015] Preferably, the triazine compound has the following structural formulae 7-10:

[0016]

[0017] The second aspect of the present application provides a preparation method of the intumescent flame retardant of the first aspect, comprising the following steps: reacting a triazine compound and an aminophosphonic acid in water to obtain the intumescent flame retardant.

[0018] Preferably, the reaction temperature is 70-100℃.

[0019] More preferably, the reaction temperature is 85-95℃.

[0020] Preferably, the reaction time is 3-7h.

[0021] More preferably, the reaction time is 3-5h.

[0022] Preferably, the mass ratio of water to aminophosphonic acid is (10-30):1.

[0023] More preferably, the mass ratio of water to aminophosphonic acid is (10-20):1.

[0024] The third aspect of the present application provides a flame-retardant polyolefin comprising the intumescent flame retardant of the first aspect.

[0025] Preferably, the mass percentage of the triazine-based compound in the flame-retardant polypropylene is 15-25%.

[0026] More preferably, the mass percentage of the triazine-based compound in the flame-retardant polypropylene is 20-23%.

[0027] Preferably, the flame-retardant polyolefin comprises the following components: polyolefin, lubricant, antioxidant, coupling agent and the triazine-based compound of the first aspect.

[0028] Preferably, the flame-retardant polyolefin is prepared from the following mass percentage components: polyolefin 75%-84%, lubricant 0.3%-0.5%, antioxidant 0.1%-0.3%, coupling agent 0.2%-0.4% and the triazine-based compound of the first aspect 15-25%.

[0029] More preferably, the flame-retardant polypropylene is prepared by the following preparation method: the components are extrusion granulated to obtain the flame-retardant polypropylene.

[0030] Further preferably, the temperature of the extrusion is 170-195℃.

[0031] More preferably, the lubricant is a combination of internal lubricant and external lubricant.

[0032] More preferably, the coupling agent is a titanate coupling agent.

[0033] Preferably, the flame-retardant polyolefin is a flame-retardant polypropylene.

[0034] The beneficial effects of the present application are:

[0035] The present application provides an intumescent flame retardant, which is a compound formed by ionically bonding a triazine compound and an aminophosphonic acid, wherein the aminophosphonic acid compound contains both phosphorus and nitrogen elements, and the triazine compound is a class of compounds rich in tertiary nitrogen structure, so that the combination of the two characteristics can prepare a "three-source" integrated intumescent flame retardant, and the triazine compound can balance the phosphorus and nitrogen of the flame retardant. The triazine-based compound of the present application is ionically bonded, and the obtained ionic flame retardant can be uniformly dispersed in the polymer. After dissolving or dispersing in the high molecular material, the flame-retardant performance of the triazine compound aminophosphonate is utilized to achieve the effect of efficient flame retardation.

[0036] Specifically, the present application has the following advantages compared with the prior art:

[0037] (1) The application further provides a preparation method of the intumescent flame retardant, which is prepared in a water reaction system without using an organic solution, and has the characteristics of simple process, green environmental protection and convenient industrial production.

[0038] (2) The application further provides a flame-retardant polyolefin; currently reported synthesis of the three-source integrated intumescent flame retardant has low flame-retardant efficiency on the polyolefin material, and the addition amount needs to be more than 25 wt% to achieve UL-94 V-0 level of vertical combustion test; the flame-retardant polypropylene provided by the application uses triazine-based compounds as the flame retardant, has less flame-retardant addition amount and good flame-retardant performance, and realizes the flame-retardant effect of UL-94 V-0 level under the condition of low addition amount of 21 wt%. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The infrared spectrum of the triazine compound 1 cyanurate flame retardant provided for example 1 is shown in the figure;

[0040] Figure 2 The infrared spectrum of the triazine compound 2 cyanurate flame retardant provided for example 2 is shown in the figure;

[0041] Figure 3 The infrared spectrum of the triazine compound 3 cyanurate flame retardant provided for example 3 is shown in the figure;

[0042] Figure 4 The infrared spectrum of the triazine compound 4 cyanurate flame retardant provided for example 4 is shown in the figure. DETAILED DESCRIPTION

[0043] The content of the application is further described in detail through specific examples. In the following examples, the raw materials, unless otherwise specified, can be obtained from conventional commercial channels or prepared and separated by simple synthesis; the processes, unless otherwise specified, all adopt conventional processes in the art.

[0044] Example 1

[0045] The example provides an intumescent flame retardant, and a preparation method thereof is specifically as follows:

[0046] The triazine compound 1 (55.6 g, 0.2 mol), an aqueous solution of aminotri (methylene) phosphonic acid (concentration 50%, 119.6 g, 0.2 mol) and 1500 mL of water are placed in a 2L round-bottom flask, then stirred and reacted at 90 DEG C for 4 hours, after the reaction is completed, the temperature is reduced to room temperature, and then the triazine compound 1 aminotri (methylene) phosphonic acid salt, i.e. the intumescent flame retardant, is prepared through filtration, drying and crushing treatment;

[0047] The structural formula of the triazine compound 1 is as follows:

[0048]

[0049] The structural formula of the triazine compound 1 aminotri (methylene) phosphonate is:

[0050]

[0051] The infrared spectrum of the triazine compound 1 aminotri (methylene) phosphonate is shown in Figure 1 .

[0052] Example 2

[0053] This example provides an intumescent flame retardant, and the preparation method is as follows:

[0054] The triazine compound 2 (67.6 g, 0.2 mol), an aqueous aminotri (methylene) phosphonic acid solution (concentration 50%, 119.6 g, 0.2 mol) and 1500 mL of water were placed in a 2 L round-bottom flask, and then stirred at 90°C for 4 hours. After the reaction was completed, the temperature was lowered to room temperature, and then the triazine compound 2 aminotri (methylene) phosphonate, i.e. the intumescent flame retardant, was prepared by filtration, drying and crushing treatment.

[0055] The structural formula of the triazine compound 2 is:

[0056]

[0057] The structural formula of the triazine compound 2 aminotri (methylene) phosphonate is:

[0058]

[0059] The infrared spectrum of the triazine compound 2 aminotri (methylene) phosphonate is shown in Figure 2 .

[0060] Example 3

[0061] This example provides an intumescent flame retardant, and the preparation method is as follows:

[0062] The triazine compound 3 (38.8 g, 0.2 mol), an aqueous aminotri (methylene) phosphonic acid solution (concentration 50%, 119.6 g, 0.2 mol) and 1500 mL of water were placed in a 2 L round-bottom flask, and then stirred at 90°C for 4 hours. After the reaction was completed, the temperature was lowered, and then the triazine compound 3 aminotri (methylene) phosphonate, i.e. the intumescent flame retardant, was prepared by filtration, drying and crushing treatment.

[0063] The structural formula of the triazine compound 3 is:

[0064]

[0065] The structural formula of the triazine compound 3 aminotri (methylene) phosphonate is:

[0066]

[0067] The infrared spectrum of the triazine compound 3 aminotrimethylene phosphonate salt is shown in Figure 1. Figure 3 .

[0068] Example 4

[0069] The present example provides an intumescent flame retardant, and the preparation method is specifically as follows:

[0070] The triazine compound 4 (58 g, 0.2 mol), an aqueous aminotrimethylene phosphonic acid solution (concentration 50%, 119.6 g, 0.2 mol) and 1500 mL of water were placed in a 5 L round-bottom flask, and the reaction was stirred at 90°C for 4 hours. After the reaction was completed, the temperature was lowered, and the product was treated by filtration, drying and crushing to obtain the triazine compound 4 aminotrimethylene phosphonate salt, i.e. the intumescent flame retardant;

[0071] The structural formula of the triazine compound 4 is as follows:

[0072]

[0073] The structural formula of the triazine compound 4 aminotrimethylene phosphonate salt is as follows:

[0074]

[0075] The infrared spectrum of the triazine compound 4 aminotrimethylene phosphonate salt is shown in Figure 1. Figure 4 .

[0076] Experimental analysis

[0077] The products of Examples 1-4 were tested for flame retardant properties, and the specific test method and results are as follows:

[0078] The flame-retardant PP sample was prepared according to the formulation in Table 1 below. Specifically, the raw materials were added to a mixer, the rotation speed was set to 1000 rpm, and the mixture was stirred for 3 minutes. Then, the mixed material was extruded using a co-rotating twin-screw extruder (Nanjing Kao Ya) with a length-diameter ratio of 48:1 and a screw diameter of 36 mm. The extruder temperature was set to 170-195°C, the rotation speed was 200 rpm, the vacuum degree was -0.8 MPa, and the particles were cooled in water at 25±5°C and then cut into granules. The granules were placed in a blast drying machine and dried at a temperature of 85°C for 3 hours to prepare flame-retardant PP material sample 1-4 corresponding to the flame retardants of Examples 1-4, respectively. The injection molding temperature was set to 180-195°C, and then the particles were injection molded into standard samples for UL 94 flame retardant testing. The test results are shown in Table 2.

[0079] Table 1 Raw material composition table of flame-retardant PP material (mass parts)

[0080]

[0081]

[0082] Table 2 Test results of flame retardant properties of flame retardant PP materials

[0083]

[0084] From the test results of the flame retardant applications of the flame retardants of Examples 1-4 in PP, it can be seen that the flame retardants of Examples 1-4 have good flame retardant properties. This is because the flame retardants of Examples 1-4 contain complete and balanced "three-source" components of intumescent flame retardants in a single molecule, and thus have good flame retardant properties.

[0085] The above describes the preferred embodiments of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the protection scope of the present application.

Claims

1. An intumescent flame retardant characterized by, The intumescent flame retardant is a compound formed by ionically bonding a triazine compound and an aminophosphonic acid; The aminophosphonic acid has a structural formula as shown in the following formula 1 to formula 6: Formula 1, Formula 2, Formula 3, Formula 4, Formula 5, Formula 6; The triazine compound has a structural formula as shown in the following formula 7 to formula 10: Formula 7, Formula 8, Formula 9, Formula 10.

2. Intumescent flame retardant according to claim 1, characterized in that The molar ratio of the triazine compound to the aminophosphonic acid is (0.5-3):

1.

3. Process for the preparation of intumescent flame retardants according to any of claims 1-2, characterized in that, The method comprises the following step: reacting the triazine compound and the aminophosphonic acid in water to obtain the intumescent flame retardant.

4. The preparation method according to claim 3, characterized in that, The reaction temperature is 70-100 DEG C; and / or the reaction time is 3-7 h.

5. The preparation method according to claim 3, characterized in that, The mass ratio of the water to the aminophosphonic acid is (10-30):

1.

6. A flame-retardant polyolefin, characterized in that, The intumescent flame retardant comprises the intumescent flame retardant according to any one of claims 1-2.

7. The flame retardant polyolefin according to claim 6, characterized in that, The flame-retardant polyolefin further comprises the following components: polyolefin, lubricant, antioxidant, coupling agent.

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