CN106349507B - A kind of preparation method of modenite-red phosphorus synergistic fire retardant - Google Patents

Abstract

The present invention relates to a preparation method of a mordenite-red phosphorus synergistic flame retardant. In the method, the mordenite is mixed with a certain amount of 0.1mol/L _NiCl solution, ion-exchanged at 60°C for 40-150min, filtered, Wash and dry, then place in a quartz tube reactor, feed hydrogen at 400-450°C for 30-120min, then feed phosphine at 410-440°C for 3-10h, and finally put the sample in the air-isolated reaction The container is heated and kept at 260-290° C. for 10-60 minutes to obtain a mordenite-red phosphorus synergistic flame retardant loaded with 3-29% (mass ratio) red phosphorus in the pores. The preparation process of the invention is relatively simple, which solves the shortcomings of using the red phosphorus flame retardant alone, and the prepared flame retardant has good flame retardant performance.

Description

A kind of preparation method of mordenite-red phosphorus synergistic flame retardant

technical field

The invention belongs to the technical field of flame retardants, and in particular relates to a preparation method of a mordenite-red phosphorus synergistic flame retardant.

Background technique

With the enhancement of people's awareness of health and environmental protection, it has become an inevitable trend in the flame retardant industry to seek environmentally friendly, low-toxicity, high-efficiency, and multi-functional flame retardants. New flame retardant technologies such as ultra-fine technology, microencapsulation technology, compounding technology, and cross-linking technology are constantly developing.

In modern flame retardant technology, the compounding of flame retardant is an extremely important aspect. Compounding is to use the interaction between flame retardants to improve the flame retardant performance, that is, the synergistic effect of flame retardants. The flame retardant system with synergistic effect has good flame retardant effect and enhanced flame retardant performance. It can not only flame retardant but also suppress smoke, and also has some special functions. It has a wide range of applications, low cost, and can significantly improve economic benefits. One of the effective ways of non-halogenation of reagents. When red phosphorus is used in combination with other flame retardants, it has a significant flame retardant synergistic effect.

Inorganic flame retardants have the characteristics of good stability, non-toxic or low toxicity, low corrosion, and low price, but their flame retardant efficiency is low, and usually need to be added in large quantities to have a good flame retardant effect. Therefore, while improving the flame retardant performance of the product, its processing performance will be deteriorated, and the mechanical properties will be greatly reduced, which will seriously affect the quality of the product. Studies have shown that the smaller the particle size of the flame retardant, the greater the dispersion in the substrate, and the better the flame retardant effect. In recent years, nanotechnology has developed rapidly, and nanomaterials have been widely used. The particle size of flame retardants used today is generally at the micron level. If it is reduced to the nanometer level, the flame retardant effect will be significantly improved, and the amount of flame retardants added will be greatly reduced. , which can solve the contradiction between the flame retardancy and mechanical properties of materials.

Phosphorus-based flame retardants have become popular materials for flame retardants due to their high efficiency, low toxicity, and low smoke. Red phosphorus is an excellent flame retardant. Metaphosphoric acid, so that the surface of the burning polymer is carbonized. On the one hand, the carbonized layer can reduce the release of combustible gas, and on the other hand, it also has a heat absorption effect; H·, HO· radicals. However, when red phosphorus is used, there are the following problems: it is flammable and explosive, and it will release highly toxic PH ₃ gas when it is in contact with air for a long time; it is red in itself, which is easy to color the product; it is easy to absorb water and has poor compatibility with polymers. The above shortcomings severely limit the direct application of red phosphorus. Treating red phosphorus with microencapsulation technology can overcome the above-mentioned shortcomings in the performance of red phosphorus and eliminate hidden dangers in the storage, transportation, production and processing of red phosphorus. The application range of red phosphorus; the third is that it can improve the compatibility with the substrate and reduce the impact on the physical and mechanical properties of the substrate; the fourth is that a variety of flame retardant elements (flame retardants) can be realized through the selection of capsule materials. Compounding, improve the performance of flame retardant and smoke suppression. Longchao Du, Baojun Qu and Zhenjin Xu. Flammability characteristics and synergistic effect of hydrotalcite with microencapsulated red phosphorus inhalogen-free flame retardant EVA composite . Polymer Degradation and Stability91 (2006) 995-1001.). Although the flame retardant effect of red phosphorus microcapsules is good, its preparation process is relatively complicated, and the particle size of the flame retardant is not easy to control, which limits its wide use.

Porous materials can be applied to flame retardants to improve the performance of flame retardants, especially to improve the thermal stability of polymer materials. At present, some scientific researchers have carried out research on the performance of this kind of flame retardants. Ye Lei et al. studied the synergistic flame retardant effect of multi-walled carbon nanotubes and magnesium hydroxide on ethylene-vinyl acetate copolymers. When the addition of multi-walled carbon nanotubes was 2%, it could significantly reduce the flame retardancy of ethylene-vinyl acetate copolymer. The heat release rate of the copolymer, the mass loss rate reaches 50%-60%, and the oxygen index of the flame retardant is increased by 5% (Lei Ye, Qianghua Wu and Baojun Qu. Synergistic effects and mechanism of multiwalled carbon nanotubes with magnesiumhydroxide in halogen-free flame retardant EVA/MH/MWNT nanocomposites. Polymer Degradation and Stability 94 (2009) 751–756.).

The ideal unit cell composition of mordenite is Na ₈ Al ₈ Si ₄₀ O ₉₆ ·24H ₂ O. It is a framework aluminosilicate with high thermal stability and catalytic activity. China is rich in natural mordenite resources. In its crystal structure, there are four-membered rings, five-membered rings, six-membered rings, and eight-membered rings. flammability.

The purpose of the present invention is to combine the good flame retardant properties of red phosphorus, the advantages of mordenite porous material and the synergistic effect of flame retardants, which not only solves the shortcomings of using red phosphorus flame retardants alone, but also can The flame retardant with particle size of submicron and uniform particle size is prepared. The flame retardant retains the advantages of high efficiency, low smoke, and low toxicity of red phosphorus flame retardants, and also exerts the synergistic enhancement effect of mordenite on red phosphorus flame retardancy, and can effectively control the particle size of flame retardants. Additives can also improve compatibility with organic materials and help improve the mechanical properties and thermal stability of flame retardant composites. The mordenite-loaded red phosphorus flame retardant prepared by the invention has broad application prospects in the flame retardant fields of organic coatings and polymer film materials.

Contents of the invention

The technical scheme adopted in the present invention is: a preparation method of a mordenite-red phosphorus synergistic flame retardant. The present invention uses mordenite and phosphine as main raw materials, and first loads Ni in the channels of mordenite, and then makes phosphine The mordenite zeolite is catalyzed and decomposed by Ni to generate yellow phosphorus, and then the yellow phosphorus is converted into red phosphorus to obtain an ultrafine mordenite-red phosphorus synergistic flame retardant. Include the following steps:

(1) Mix mordenite with a certain amount of 0.1mol/L NiCl ₂ solution, ion-exchange at 60°C for a certain period of time, filter, wash, and dry to obtain mordenite loaded with Ni ²⁺ in the pores;

(2) Put the sample prepared in (1) in a quartz tube reactor, pass through hydrogen at a certain temperature and reduce it for a certain period of time to obtain Ni-loaded mordenite in the pores;

(3) Put the Ni-loaded mordenite prepared in (2) in a quartz tube reactor, and feed phosphine at a certain temperature for a certain period of time, so that the phosphine is decomposed into yellow phosphorus in the mordenite pores;

(4) Heat the sample prepared in (3) to a certain temperature in an air-isolated reaction vessel, hold it for a certain period of time, convert yellow phosphorus into red phosphorus, and obtain a mordenite-red phosphorus synergistic flame retardant loaded with red phosphorus in the pores .

In a preferred embodiment, the mordenite is natural mordenite with a particle size of 0.3-1 μm.

In a preferred embodiment, the mordenite is mixed with a 0.1 mol/L NiCl ₂ solution, and the ion exchange time at 60° C. is 40-150 min.

In a preferred embodiment, the Ni ²⁺ supported in the pores of the mordenite is reduced in hydrogen at a temperature of 400-450° C. for 30-120 minutes.

In a preferred embodiment, the temperature at which the phosphine decomposes in the channels of mordenite is 410-440° C., and the time is 3-10 hours.

In a preferred embodiment, the heating temperature for converting yellow phosphorus into red phosphorus is 260-290° C., and the heating time is 10-60 minutes.

The red phosphorus content of the product prepared by the invention is 3-29% (mass ratio).

The advantage of the flame retardant prepared by the invention is that it solves the shortcomings of using the red phosphorus flame retardant alone, and can prepare a flame retardant with submicron size and uniform particle size. The flame retardant retains the advantages of high efficiency, low smoke, and low toxicity of red phosphorus flame retardants, and also exerts the synergistic enhancement effect of mordenite on red phosphorus flame retardancy, and can effectively control the particle size of flame retardants Additives can also improve compatibility with organic materials and help improve the mechanical properties and thermal stability of flame retardant composites. The preparation technology of the invention can effectively control the decomposition of phosphine gas in the channels of the mordenite, and can control the high-efficiency flame-retardant component red phosphorus to only enter the channels of the mordenite without depositing on the surface of the zeolite, and the preparation process is relatively simple. The invention also provides a new approach for solving the by-product phosphine gas in the sodium hypophosphite industry.

Detailed ways

Example 1

Mix 20g of mordenite with a median particle size of 0.3μm and 500mL of 0.1mol/L NiCl ₂ solution, stir at 60°C for 150min, filter, wash and dry, place in a quartz tube reactor, pass through the reactor at 450°C After injecting hydrogen for 120 minutes, feed phosphine at 440°C and react for 10 hours. After cooling, heat the sample to 290°C in an air-insulated reaction vessel and keep it warm for 60 minutes to obtain a mordenite with a red phosphorus content of 29%. The flame retardant of red phosphorus, the oxygen index of the flame retardant material prepared by mixing the flame retardant with polyethylene is 33.1.

Example 2

Mix 20g of mordenite with a median particle size of 1μm and 500mL of 0.1mol/L NiCl ₂ solution, stir at 60°C for 40min, filter, wash and dry, place in a quartz tube reactor, and pass it through at 400°C After 30 minutes of hydrogen gas, phosphine was introduced at 410°C for 3 hours of reaction. After cooling, the sample was heated to 260°C in a reaction vessel isolated from air, and kept for 10 minutes to obtain red phosphorus loaded in the pores of mordenite with a red phosphorus content of 3%. Phosphorus flame retardant, the oxygen index of the flame retardant material prepared by mixing the flame retardant with polyethylene is 27.8.

Example 3

Mix 20g of mordenite with a median particle size of 0.65μm and 500mL of 0.1mol/L NiCl ₂ solution, stir at 60°C for 95min, filter, wash and dry, place in a quartz tube reactor, pass through the reactor at 425°C After injecting hydrogen for 75 minutes, feed phosphine at 425°C and react for 6.5 hours. After cooling, heat the sample to 275°C in an air-insulated reaction vessel and keep it warm for 35 minutes to obtain a mordenite with a red phosphorus content of 15%. The flame retardant loaded with red phosphorus, the oxygen index of the flame retardant material prepared by mixing the flame retardant with polyethylene is 31.3.

Example 4

Mix 20g of mordenite with a median particle size of 0.3μm and 500mL of 0.1mol/L NiCl ₂ solution, stir at 60°C for 150min, filter, wash and dry, place in a quartz tube reactor, pass through the reactor at 450°C After injecting hydrogen for 30 minutes, feed phosphine at 440°C and react for 10 hours. After cooling, heat the sample to 290°C in an air-insulated reaction vessel and keep it warm for 60 minutes to obtain mordenite with a red phosphorus content of 9%. The flame retardant of red phosphorus, the oxygen index of the flame retardant material prepared by mixing the flame retardant with polyethylene is 29.0.

Example 5

Mix 20g of mordenite with a median particle size of 0.3μm and 500mL of 0.1mol/L NiCl ₂ solution, stir at 60°C for 150min, filter, wash and dry, place in a quartz tube reactor, pass through the reactor at 450°C After injecting hydrogen for 120 minutes, feed phosphine at 440°C, react for 7 hours, and after cooling, heat the sample to 290°C in a reaction vessel isolated from air, and keep it warm for 60 minutes to obtain mordenite with a red phosphorus content of 23%. The flame retardant of red phosphorus, the oxygen index of the flame retardant material prepared by mixing the flame retardant with polyethylene is 32.5.

Oxygen index (flame retardant performance) test experiment:

Mix the flame retardants prepared in the above examples 1, 2, 3, 4 and 5 with polyethylene (the flame retardant accounts for 30%), knead with twin rolls at 120°C for 10 minutes, and make a thin sheet with a thickness of 1mm sample. The oxygen index test is carried out in accordance with GB/T2406-1993.

Claims (1)

1. a preparation method of mordenite-red phosphorus synergistic flame retardant, is characterized in that, comprises the following steps: take mordenite, phosphine as main raw material, with the NiCl of a certain amount of 0.1mol/L of mordenite ₂ solution Mix, ion-exchange at 60°C for a certain period of time, filter, wash, and dry to obtain mordenite loaded with Ni ²⁺ in the pores, then put it in a quartz tube reactor, and pass hydrogen gas at a certain temperature to obtain the mordenite loaded with Ni 2+ in the pores. Ni mordenite, and then feed phosphine at a certain temperature to decompose phosphine into yellow phosphorus in the pores of mordenite, and heat it to a certain temperature in a reaction vessel isolated from air to convert yellow phosphorus into red Phosphorus _, to obtain the mordenite-red phosphorus synergistic flame retardant loaded with red phosphorus in the channel; The Ni ²⁺ loaded in the channel can be reduced in hydrogen at a temperature of 400-450°C and the time is 30-120min; the decomposition temperature of phosphine in the mordenite channel is 410-440°C and the time is 3-10h; the conversion of yellow phosphorus The heating temperature for the red phosphorus is 260-290° C., and the time is 10-60 minutes; the content of the prepared flame retardant red phosphorus is 3-29wt%.