WO2017173979A1

WO2017173979A1 - Highly effective non-halogen composite flame retardant and preparation method therefor

Info

Publication number: WO2017173979A1
Application number: PCT/CN2017/079458
Authority: WO
Inventors: 耿建新; 许林利; 黄勇
Original assignee: 中国科学院理化技术研究所
Priority date: 2016-04-05
Filing date: 2017-04-05
Publication date: 2017-10-12
Also published as: CN107286371A; CN107286371B

Abstract

Disclosed in the present invention are a highly effective non-halogen composite flame retardant and a preparation method therefor. The composite flame retardant is made up of the following raw material components by weight: 100 parts graphite-type material; 50-600 parts phosphorus-type flame retardant. Also disclosed is a preparation method for said composite flame retardant. The process of the technical solution of the present invention is simple, and the production period is short; graphite-type material is converted into a graphene-type material, realizing a composite of graphite-type material and phosphorus-type flame retardant; the composite flame retardant obtained is characterized by a high specific surface area, not agglomerating easily, being easily dispersed in ionic and non-ionic solvents, high flame retardant effectiveness, and good smoke suppression; the composite can be used as a flame retardant and enhancer in multiple types of saturated resin, unsaturated resin, hot melt adhesive, rubber and coating, and can also improve wear resistance of rubber and corrosion resistance of coatings.

Description

High-efficiency halogen-free composite flame retardant and preparation method thereof

Technical field

The invention relates to the field of carbon material technology. More specifically, it relates to a high-efficiency halogen-free composite flame retardant and a preparation method thereof.

Background technique

Halogen-free, low-smoke, low-toxic environmentally-friendly flame retardants have always been the goal of the people, and the global development of halogen-free flame retardants and flame retardant materials has also invested a lot of power. The main types of halogen-free flame retardants are phosphorus-based flame retardants and inorganic hydrates. Phosphorus-based flame retardants have good flame retardant effect, high flame retardant efficiency, excellent thermal stability, non-volatility, and no corrosive gases. And the characteristics of good electrical insulation, and China's phosphorus resource storage is richer, with lower cost advantages.

However, phosphorus-based flame retardants also have a series of disadvantages, such as poor compatibility with most polymers, difficulty in dispersion in the resin, resulting in a decrease in the mechanical properties of the material; a large amount of white smoke is generated during combustion. Therefore, there are articles reported (Journal of Zhengzhou University of Light Industry, 2004, 19: 13-15) that the expanded graphite and red phosphorus are combined as a flame retardant for polypropylene, which has high flame retardancy and effectively reduces the amount of white smoke, but The flame retardant simply mixes graphite with red phosphorus, and the particles of the flame retardant are large, which is not conducive to dispersion, and is not conducive to further improvement of flame retardant efficiency. In addition, it has been reported in the article (ACS nano, 2014, 8: 2820-2825) that the red phosphorus and expanded graphite are ball milled, and the graphene phosphate is obtained by separation and purification. The flame retardancy of graphene phosphate and the polar solvent are studied. Dispersibility. The product in this document is graphene phosphate. The authors only emphasize the flame retardancy of graphene phosphate, and in order to obtain pure graphene phosphate element, a number of steps such as separation and purification are added. It has also been reported in the literature (Chem. Eur. J., 2015, 21: 15480-15485) that graphene oxide is grafted with phosphoric acid, and the obtained graphene oxide phosphoric acid also has good dispersibility and high flame retardancy. The techniques reported in these two articles are based on graphene or graphene oxide. The size of graphene phosphate prepared is small, which is favorable for uniform dispersion in polar solvents. It emphasizes the flame retardant properties of graphene phosphate, but preparation The process involves multiple experimental steps, the process is complicated, the preparation efficiency is low, the cost is high, and the utilization rate of the raw material phosphorus-containing flame retardant is very low.

Therefore, it is necessary to provide a halogen-free composite flame retardant having a wide source of raw materials, a simple preparation process, high utilization rate of raw materials, and high-efficiency flame retardancy, and a preparation method thereof.

Summary of the invention

It is an object of the present invention to provide a high efficiency halogen-free composite flame retardant.

Another object of the present invention is to provide a process for preparing a high-efficiency halogen-free composite flame retardant.

In order to achieve the first object of the present invention, the present invention employs the following technical solutions:

A high-efficiency halogen-free composite flame retardant consisting of the following parts by weight:

100 parts of graphite materials;

Phosphorus flame retardant 50-600 parts.

Preferably, it consists of the following parts by weight of raw materials:

100 parts of graphite materials;

Phosphorus flame retardants 50 to 390 parts.

Phosphorus flame retardants have excellent flame retardant effect and electrical insulation properties, but they also have their own shortcomings, such as poor compatibility with most polymers, difficult to disperse in the resin, resulting in a decrease in the mechanical properties of the material. A lot of white smoke is produced when burning. It is a more effective means to overcome the above disadvantages by preparing a composite flame retardant by compounding a flame retardant or a synergistic flame retardant with complementary performance. Therefore, how to reduce the amount of phosphorus substances in the composite flame retardant and ensure the flame retardant and smoke suppressing effect of the composite flame retardant are technical problems to be solved by those skilled in the art.

Graphite-based materials have the property of being non-toxic and producing less flue gas, and are currently widely used in the flame retardant field of resins. However, since graphite materials have the disadvantage of limited flame retardancy, they are not suitable for use as a flame retardant alone. The applicant has found through extensive research that the composite materials prepared by the graphite material and the phosphorus flame retardant in the form of ball milling under anaerobic conditions have very excellent flame retardant effects. Compared with the prior art, the present application can effectively improve the utilization efficiency of raw materials (including graphite and phosphorus) and increase the utilization efficiency of phosphorus to 100%. Although phosphorus-based materials exist in various forms in composite flame retardants, including graphene phosphoric acid and a large amount of micronized phosphorus-containing flame retardant particles, they do not affect the flame retardancy of the composite. And the obtained composite material can be stably existed in the air, and most importantly, has good solubility in both polar and non-polar solvents, and effectively solves the problem that the flame retardant has poor dispersibility in the material. .

Preferably, the graphite-based material is selected from the group consisting of flaky graphite, massive graphite, amorphous graphite, artificial graphite, expanded graphite, and one or more of the above various types of graphite oxide.

Preferably, the phosphorus-based flame retardant is selected from the group consisting of red phosphorus, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, polyphosphoric acid amine, phosphorus amine, trihydroxy phosphate, alkyl phosphate, aryl phosphate, cyclic phosphoric acid. Ester, triphenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite One or more of triphenyl phosphite, an organic phosphorus salt, a phosphorus heterocyclic compound, a polymer phosphorus (phosphonate), and a metal phosphinate.

More preferably, the graphite-based material is preferably expanded graphite or flaky graphite; and the phosphorus-based flame retardant is preferably red phosphorus. This preference is to further analyze the physical and chemical interactions that occur between the materials during ball milling and the composition of the composite flame retardant after ball milling. Compared with other phosphorus flame retardants, red phosphorus has a single composition and high flame retardant efficiency, while expanded and flaky graphite are the preferred raw materials for the preparation of graphene by ball milling.

Preferably, the composite flame retardant is composed of two or more of graphene, graphene phosphoric acid, graphene oxide, phosphorylated graphite, graphite oxide, graphite, phosphorus flame retardant, phosphorus pentoxide and elemental phosphorus. composition. The composite flame retardant contains not only the raw material graphite and the phosphorus-based flame retardant, but also graphene, graphene phosphoric acid, graphene oxide, graphene oxide phosphate, graphite phosphoric acid which are formed by the mutual separation or chemical reaction of the two raw materials. Graphite phosphoric acid, phosphorus pentoxide and nano-dispersed elemental phosphorus, etc., which are produced by these reactions, have superior flame retardancy and resistance compared with simple mixing of pure graphite materials and phosphorus flame retardants. The synergistic performance and smoke suppression effect of the fuel, as well as the superior dispersibility and reinforcing effect in the matrix of resin, hot melt adhesive, paint or rubber, and at the same time improve the wear resistance of the rubber and the corrosion resistance of the coating.

The morphology of the composite flame retardant is a mixture of a two-dimensional sheet structure and nano-fine particles, a two-dimensional sheet-like structure graphene sheet size of 50 nm to 50 μm, and a phosphorus flame retardant particle size of 10 nm to 1 μm. The surface area is 20-200 m ² /g; the solubility of the composite flame retardant in deionized water is 0.15-0.9 mg/mL; the solubility of the composite flame retardant in dimethylformamide is 0.2-1.2 mg/ The solubility of the composite flame retardant in chloroform is 0.05-0.85 mg/mL; the solubility of the composite flame retardant in tetrahydrofuran is 0.05-0.80 mg/mL; the composite flame retardant is in xylene The solubility is 0.02 to 0.75 mg/mL, and the superiority of the composite flame retardant is exhibited by a larger specific surface area, nanodispersion of a phosphorus-based flame retardant, and excellent dispersibility in a polar and non-polar solvent.

In order to achieve the second object of the present invention, the present invention adopts the following technical solutions:

The preparation method of the high-efficiency halogen-free composite flame retardant as described above comprises the following steps:

1) According to 100 parts by weight of the graphite material, 50 to 600 parts of the phosphorus flame retardant, and 10 to 5000 parts of the steel ball are placed in the steel sealed can, and the sealed tank is kept in a vacuum or an inert gas state;

2) After ball milling for 1 to 72 hours at a ball milling speed of 20 to 750 rpm, the obtained powder is a halogen-free composite flame retardant.

The mechanism for preparing the high-efficiency halogen-free composite flame retardant of the invention is as follows: the graphite material and the phosphorus flame retardant are mutually peeled off during the ball milling process, the thickness of the sheet layer is gradually thinned, and the dispersion is very uniform, which is beneficial to the flame retardant flame retardant. The performance is greatly improved; in the process of stripping and thinning of the graphite material, the phosphorus flame retardant also realizes nanodispersion, and at the same time, the active phosphorus easily reacts with the edge of the graphene material after stripping to form graphene. Phosphoric acid or phosphorylated graphite material, while graphene phosphate or phosphorylated graphite material has high efficiency flame retardant performance; in the ball milling process, the presence of phosphorus flame retardant contributes to the stripping of graphite materials, on the other hand, graphite The graphene obtained by exfoliation of the olefin material is favorable for dispersing the phosphorus-based flame retardant to obtain nanoparticles, and the nano-dispersion of phosphorus further contributes to the improvement of the performance of the composite flame retardant.

Preferably, in the step 1), the steel ball has a diameter of 2 to 130 mm, and the steel sealed can has a volume of 0.05 to 1000 L. If the diameter of the steel ball or the volume of the steel sealed can is too large or too small, it is not conducive to the mutual shearing and peeling action of the raw materials and the chemical reaction. The volume of the steel sealed can is matched with the diameter of the steel ball to facilitate the peeling and refinement of the composite flame retardant. The chemical reaction can effectively improve the flame retardant performance of the composite flame retardant and reduce the amount of smoke.

Preferably, in step 1), 100 parts by weight of the graphite-based material, 50 to 390 parts of the phosphorus-based flame retardant, and 1000 to 1500 parts of the steel ball are placed in the steel sealed can; the diameter of the steel ball is 4 to 6 mm. . The most suitable raw material ratio, steel ball weight and steel ball diameter can obtain a composite flame retardant with uniform size distribution, large specific surface area, good solubility and excellent flame retardant efficiency and low smoke generation.

Preferably, in step 2), the ball milling speed is 400 to 500 rpm, and the ball milling time is 12 to 48 hours. The ball milling speed and the ball milling time also affect the physicochemical properties of the composite flame retardant. When the ball milling speed is too large and the ball milling time is too long, the energy consumption and equipment loss when preparing the composite flame retardant are large; otherwise, the composite flame retardant is obtained. The physical and chemical properties of the flame retardant are poor.

In the prior art, research on graphite materials and phosphorus flame retardants has focused on a simple mixing of the two, or a reactant of graphene phosphate or phosphorylated graphene. In the work of the present application, the flame retardant product is a composite, graphene phosphate is only one of the components, and also includes nano-dispersed micronized phosphorus-containing flame retardant particles. The present application studies the problem of graphite materials for improving the compatibility and dispersibility of phosphorus flame retardants, emphasizing that the nano-dispersion of free phosphorus has better flame retardant effect than bulk phosphorus; the composite flame retardant High-efficiency flame-retardant and smoke-suppressing energy synergy between nano-dispersed phosphorus and graphene.

Since the different components of the prepared composite flame retardant produced by the invention have high efficiency flame retardancy or flame retardant synergy, the invention has simple process, short production cycle and relatively low production cost compared with the prior art. Low-yield, high raw material conversion rate, and the characteristics of large specific surface area, easy dispersion in polar solvents, high efficiency flame retardancy and smoke suppression, can be widely used in a variety of saturated resins, unsaturated resins, hot melt adhesives, Flame retardant of rubber, paint and other products. Since carbon materials such as graphite, graphite derivatives, graphene or graphene derivatives have wear resistance and chemical resistance, the wear resistance of the rubber and the corrosion resistance of the coating can be improved at the same time. At the same time, compared with the prior art, the present invention effectively improves the utilization efficiency of raw materials and increases the utilization efficiency of phosphorus to 100%. At the same time, the combination of phosphorus nanoparticles and graphene materials effectively avoids the problem of white smoke caused by poor compatibility of the phosphorus flame retardant and the material, and the release of white irritating taste. The synergistic effect of the two causes the composite flame retardant to be a two-dimensional sheet structure and a mixture of particles, the size of the two-dimensional sheet structure is 50 nm to 50 μm, the particle size is 10 nm to 1 μm, and the specific surface area is 20 to 200 m ² /g; The solubility of the composite flame retardant in deionized water is 0.15-0.9 mg/mL; the solubility of the composite flame retardant in dimethylformamide is 0.2-1.2 mg/mL; The solubility in chloroform is 0.05-0.85 mg/mL; the solubility of the composite flame retardant in tetrahydrofuran is 0.05-0.89 mg/mL; the solubility of the composite flame retardant in xylene is 0.02-0.80 mg/mL. . The obtained composite material can be stably existed in the air, and most importantly, has good solubility in polar and non-polar solvents, and effectively solves the problem that the poor flame retardant has poor dispersibility in the material.

The beneficial effects of the present invention are as follows:

The process is simple, the production cycle is short, and the utilization rate of raw materials is high, and the conversion of the graphite material to the graphene material can be realized, and the composite of the graphite material and the phosphorus flame retardant can be realized, and the obtained composite flame retardant has a large specific surface area. It is easy to agglomerate, easy to disperse in polar and non-polar solvents, high flame retardant efficiency and good smoke suppression. It can be applied to a variety of saturated resin, unsaturated resin, hot melt adhesive, rubber, paint and other products. Burning and strengthening, while improving the wear resistance of the rubber and the corrosion resistance of the coating.

DRAWINGS

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a scanning electron micrograph of a halogen-free composite flame retardant prepared in Example 3 of the present invention.

detailed description

In order to explain the present invention more clearly, the present invention will be further described in conjunction with the preferred embodiments and the accompanying drawings. Similar components in the drawings are denoted by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is intended to be illustrative and not restrictive.

Example 1

Expanded graphite 6.67g;

Red phosphorus 3.34g.

The preparation method of the composite flame retardant is as follows:

(1) 6.67 g of graphite, 3.34 g of red phosphorus, and 200 g of steel balls were placed in a 100 mL steel sealed can, and the vacuum state in the sealed can was maintained;

(2) After ball milling for 40 hours at a ball milling speed of 400 rpm, venting and opening the sealed can, the obtained black uniform powder is a halogen-free composite flame retardant.

When exposed to air, the black halogen-free composite flame retardant is stable. The powder has good solubility in polar and non-polar solvents. The solubility in deionized water is about 0.85 mg/mL in dimethylformamide. The solubility is about 0.96 mg/mL, the solubility in chloroform is 0.82 mg/mL, the solubility in tetrahydrofuran is 0.85 mg/mL, the solubility in xylene is 0.74 mg/mL, and the lamellar flame retardant particles The size is small and uniform, the two-dimensional sheet structure has a size of 50 nm to 50 μm, and the particle size is 50 nm to 1 μm.

The flame retardant effect test of the composite flame retardant is as follows:

Mixing the composite flame retardant with isotactic polypropylene to obtain a masterbatch, and mixing the composite flame retardant with nylon 66 Extrusion to obtain the masterbatch, and using the injection molding machine to form a flame-retardant test strip, to obtain 15 parts by weight of the composite flame retardant in the polypropylene, and 12 parts by weight in the nylon 66, which can make the prepared composite The material achieves 94UV-0 flame retardancy and emits less smoke.

It can be seen that the composite flame retardant is excellent in flame retardancy and smoke suppressing effect.

Example 2

Expanded graphite 5.0g;

Red phosphorus 5.0g.

The preparation method of the composite flame retardant is as follows:

(1) placing 5.0 g of graphite, 5.0 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

When exposed to air, the black halogen-free composite flame retardant is easy to ignite due to the large specific surface area. The powder has good solubility in polar and non-polar solvents, and the solubility in deionized water is about 0.88 mg/ The solubility of mL in dimethylformamide is about 1.08 mg/mL, the solubility in chloroform is 0.80 mg/mL, the solubility in tetrahydrofuran is 0.72 mg/mL, and the solubility in xylene is 0.70 mg/ The particle size of the layered flame retardant is small and uniform, and the size of the two-dimensional sheet structure is 50 nm to 10 μm, and the particle size is 10 to 300 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The amount of the flammable agent in the polypropylene is 11 parts, and the weight fraction of the nylon 66 is 10 parts, so that the prepared composite material can achieve 94UV-0 level flame retardancy and less smoke generation.

Example 3

Flaky graphite 5.0g;

Red phosphorus 5.0g.

The preparation method of the composite flame retardant is as follows:

When exposed to air, the black halogen-free composite flame retardant is easy to ignite due to the large specific surface area. The powder has good solubility in polar and non-polar solvents, and the solubility in deionized water is about 0.88 mg/ The solubility of mL in dimethylformamide is about 1.08 mg/mL, the solubility in chloroform is 0.80 mg/mL, the solubility in tetrahydrofuran is 0.72 mg/mL, and the solubility in xylene is 0.70 mg/ The particle size of the layered flame retardant is small and uniform, and the two-dimensional sheet structure has a size of 50 nm to 20 μm and a particle size of 10 to 300 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The weight fraction of the fuel in the polypropylene reaches 11.5 parts, and the weight fraction in the nylon 66 reaches 11 parts, so that the prepared composite material can achieve 94UV-0 grade flame retardancy and the amount of smoke is small.

Example 4

Expanded graphite 3.33g;

Red phosphorus 6.67g.

The preparation method of the composite flame retardant is as follows:

(1) placing 3.33 g of graphite, 6.67 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 48 hours at a ball milling speed of 480 rpm, venting and opening the sealed can, the obtained black uniform powder is a halogen-free composite flame retardant.

When exposed to air, the black halogen-free composite flame retardant is stable. The powder has good solubility in polar and non-polar solvents. The solubility in deionized water is about 0.90 mg/mL in dimethylformamide. The solubility is about 1.20 mg/mL, the solubility in chloroform is 0.85 mg/mL, the solubility in tetrahydrofuran is 0.80 mg/mL, the solubility in xylene is 0.75 mg/mL, and the lamellar flame retardant particles The size is small and uniform, the two-dimensional sheet structure has a size of 50 nm to 20 μm, and the particle size is 10 to 350 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The amount of the flammable agent in the polypropylene reaches 10 parts, and the weight fraction in the nylon 66 reaches 8.5 parts, so that the prepared composite material can achieve 94UV-0 grade flame retardancy, and the amount of smoke is small.

Example 5

Expanded graphite 2.5g;

Red phosphorus 7.5g.

The preparation method of the composite flame retardant is as follows:

(1) placing 2.5 g of graphite, 7.5 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 38 hours at a ball milling speed of 450 rpm, venting and opening the sealed can, the obtained black uniform powder is a halogen-free composite flame retardant.

When exposed to air, the black halogen-free composite flame retardant is stable. The powder has good solubility in polar and non-polar solvents. The solubility in deionized water is about 0.85 mg/mL in dimethylformamide. The solubility is about 1.05 mg / mL, the solubility in chloroform is 0.81 mg / mL, the solubility in tetrahydrofuran is 0.80 mg / mL, in two The solubility in toluene was 0.75 mg/mL, and the sheet-like flame retardant particles were small and uniform in size, and the two-dimensional sheet-like structure had a size of 50 nm to 25 μm and a particle size of 20 to 500 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The weight fraction of the fuel in the polypropylene reaches 11.5 parts, and the weight fraction of the nylon 66 reaches 10 parts, so that the prepared composite material can achieve 94UV-0 grade flame retardancy and less smoke generation.

Example 6

Expanded graphite 2.86g;

Red phosphorus 7.14g.

The preparation method of the composite flame retardant is as follows:

(1) placing 2.86 g of graphite, 7.14 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling at a ball milling speed of 420 rpm for 24 hours, venting and opening the sealed can, the obtained black uniform powder is a halogen-free composite flame retardant.

When exposed to air, the black halogen-free composite flame retardant is stable. The powder has good solubility in depolarized and non-polar solvents. The solubility in deionized water is about 0.80 mg/mL in dimethylformamide. The solubility in the solution is about 1.15 mg / mL, the solubility in chloroform is 0.85 mg / mL, the solubility in tetrahydrofuran is 0.78 mg / mL, the solubility in xylene is 0.70 mg / mL, the layered flame retardant The particle size is small and uniform, the two-dimensional sheet structure has a size of 50 nm to 30 μm, and the particle size is 20 to 500 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The parts by weight of the fuel in the polypropylene reached 11 parts, and the parts by weight in the nylon 66 reached 10.5 parts, which made the prepared composite material reach 94UV-0 level flame retardant and the amount of smoke was small.

Example 7

Expanded graphite 2.04g;

Red phosphorus 7.96g.

The preparation method of the composite flame retardant is as follows:

(1) placing 2.04 g of graphite, 7.96 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 45 hours at a ball milling speed of 460 rpm, venting and opening the sealed can, the obtained black uniform powder is a halogen-free composite flame retardant.

When exposed to air, the black halogen-free composite flame retardant is stable, and the powder dissolves in polar and non-polar solvents. The pressure is better, the solubility in deionized water is about 0.90mg/mL, the solubility in dimethylformamide is about 1.12mg/mL, the solubility in chloroform is 0.84mg/mL, and the solubility in tetrahydrofuran is The solubility of 0.75 mg/mL in xylene is 0.70 mg/mL, and the size of the lamellar flame retardant particles is small and uniform, the size of the two-dimensional sheet structure is 50 nm to 30 μm, and the particle size is 20 to 500 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The parts by weight of the flammable agent in the polypropylene reached 13.5 parts, and the parts by weight in the nylon 66 reached 12.5 parts, so that the prepared composite material reached 94UV-0 level flame retardant, but a small amount of irritating smoke was generated during combustion.

It can be seen that the composite flame retardant has good flame retardant and smoke suppressing effects.

Example 8

Expanded graphite 2.0g;

Red phosphorus 8.0g.

The preparation method of the composite flame retardant is as follows:

(1) placing 2.0 g of graphite, 8.0 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 39 hours at a ball milling speed of 420 rpm, venting and opening the sealed can, the obtained dark brown uniform powder is a halogen-free composite flame retardant.

When exposed to air, the dark brown halogen-free composite flame retardant is relatively stable. The powder has a general solubility in polar and non-polar solvents. The solubility in deionized water is about 0.42 mg/mL in dimethylformamide. The solubility in the solution is about 0.53 mg / mL, the solubility in chloroform is 0.37 mg / mL, the solubility in tetrahydrofuran is 0.36 mg / mL, the solubility in xylene is 0.32 mg / mL, the layered flame retardant The particle size is small and uniform, the two-dimensional sheet structure has a size of 50 nm to 35 μm, and the particle size is 20 to 550 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The pulverizer is 15 parts by weight in the polypropylene and 13 parts by weight in the nylon 66, so that the prepared composite material can achieve 94UV-0 flame retardancy, but irritating smoke generation upon burning.

It can be seen that the composite flame retardant has a general flame retardant and smoke suppressing effect.

Example 9

Expanded graphite 1.43g;

Red phosphorus 8.57g.

The preparation method of the composite flame retardant is as follows:

(1) placing 1.43 g of graphite, 8.57 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 26 hours at a ball milling speed of 450 rpm, deflate and open the sealed can, and the obtained dark brown color is obtained. A homogeneous powder is a halogen-free composite flame retardant.

When exposed to air, the dark brown halogen-free composite flame retardant is stable. The powder has a general solubility in polar and non-polar solvents. The solubility in deionized water is about 0.25 mg/mL in dimethylformamide. The solubility is about 0.22 mg/mL, the solubility in chloroform is 0.19 mg/mL, the solubility in tetrahydrofuran is 0.12 mg/mL, the solubility in xylene is 0.13 mg/mL, and the layered flame retardant particle size Small and uniform, the two-dimensional sheet structure has a size of 50 nm to 50 μm and a particle size of 30 to 700 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The amount of the flammable agent in the polypropylene reaches 17 parts, and the weight fraction in the nylon 66 reaches 15.5 parts, so that the prepared composite material can achieve 94UV-0 level flame retardancy, but a large amount of irritating smoke is generated during combustion.

Example 10

Flaky graphite 2.5g;

Diammonium hydrogen phosphate 7.5g.

The preparation method of the composite flame retardant is as follows:

(1) placing 2.5 g of graphite, 7.5 g of diammonium phosphate, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

When exposed to air, the black halogen-free composite flame retardant is stable. The powder has a general solubility in polar and non-polar solvents. The solubility in deionized water is about 0.38 mg/mL in dimethylformamide. The solubility is about 0.27 mg/mL, the solubility in chloroform is 0.19 mg/mL, the solubility in tetrahydrofuran is 0.17 mg/mL, the solubility in xylene is 0.16 mg/mL, and the lamellar flame retardant particle size Small and uniform, the two-dimensional sheet structure has a size of 50 nm to 15 μm and a particle size of 20 to 300 nm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The amount of the flammable agent in the polypropylene reaches 23 parts, and the weight fraction in the nylon 66 reaches 19 parts, so that the prepared composite material can reach 94UV-0 level flame retardant, but there is less smoke generation during combustion.

It can be seen that the composite flame retardant needs to add more mass fractions to achieve the flame retardant effect of the V0 grade, which will further affect the mechanical properties of the composite material.

Example 11

Amorphous graphite 2.5g;

Triethyl phosphate 7.5 g.

The preparation method of the composite flame retardant is as shown in Example 10. The physics of the finally prepared composite flame retardant The properties and flame retardant effects were similar to those of the product of Example 10.

Example 12

Artificial graphite 2.5g;

Polyphosphate amine 7.5g.

The preparation method of the composite flame retardant is as shown in Example 10. The physical properties and flame retardant effects of the finally prepared composite flame retardant were similar to those of the product of Example 10.

Example 13

Artificial graphite oxide 2.5g;

Triphenyl phosphite and trioctyl phosphate 7.5 g.

Example 14

Amorphous graphite oxide and artificial graphite 2.5g;

Polymer phosphorus (phosphonate) and red phosphorus 7.5g.

Example 15

Bulk graphite oxide and expanded graphite 2.5g;

Aryl phosphate, cyclic phosphate and red phosphorus 7.5 g.

Comparative example 1

A halogen-free composite flame retardant consisting of the following parts by weight:

Graphite 1.11g;

Red phosphorus 8.89g.

The preparation method of the composite flame retardant is as follows:

(1) placing 1.11 g of graphite, 8.89 g of red phosphorus, and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 48 hours at a ball milling speed of 480 rpm, venting and opening the sealed can, the obtained brown uniform powder is a halogen-free composite flame retardant.

When exposed to air, the brown halogen-free composite flame retardant has stable performance, poor solubility in polar and non-polar solvents, and large particle flame retardant precipitates in the solvent. Flame retardant particles are large in size and unevenly distributed, and flame retardant II The dimension of the sheet-like structure is 1 to 500 μm, and the size of the particles is 100 nm to 5 μm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The amount of the flammable agent in the polypropylene reaches 26 parts, and the weight fraction in the nylon 66 reaches 23 parts, so that the prepared composite material can reach the 94UV-0 level flame retardant, but there is a large amount of irritating smoke generation during combustion.

It can be seen that the excessive size of the flame retardant and a large amount of filling may impair the mechanical properties of the composite material, and excessive red phosphorus content may cause a large amount of smoke with irritating odor when the composite material is burned.

Comparative example 2

Expanded graphite 3.33g;

Red phosphorus 6.67g.

The preparation method of the composite flame retardant is as follows:

The graphite is 3.33g and the red phosphorus 6.67g is simply mechanically mixed. The halogen-free composite flame retardant is in a precipitate state in polar and non-polar solvents. The two-dimensional sheet structure of the flame retardant has a size of 1 to 500 μm. The size is from 500 nm to 100 μm.

The flame retardant effect test of the composite flame retardant is as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The distribution of the fuel in the resin is not uniform enough, and the obtained spline mechanical properties are brittle. The weight fraction in the polypropylene reaches 31 parts, and the weight fraction in the nylon 66 reaches 27 parts, so that the prepared composite material can achieve 94UV-0 grade flame retardancy, but there is a large amount of irritating smoke generation upon burning.

Comparative example 3

A halogen-free flame retardant consisting of the following parts by weight:

Expanded graphite 10g;

The preparation method of the flame retardant is as follows:

(1) placing 10 g of graphite and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

(2) After ball milling for 48 hours at a ball milling speed of 480 rpm, venting and opening the sealed can, the obtained black powder is a halogen-free flame retardant.

A small amount of the flame retardant can be dispersed in a polar solvent (water and dimethylformamide) in a weakly polar or non-polar solvent (chloroform, tetrahydrofuran and xylene) in a precipitated state.

The flame retardant effect of the flame retardant is tested as follows:

Adding a large amount (up to 40% by weight) of this halogen-free flame retardant to polypropylene or nylon 66 resin is difficult to achieve V0 level flame retardancy, and only reduces the amount of smoke.

From this, it is understood that graphite alone is not suitable as a flame retardant for a resin.

Comparative example 4

A halogen-free flame retardant consisting of the following parts by weight:

Red phosphorus 10g;

The preparation method of the flame retardant is as follows:

(1) placing 5 g of red phosphorus and 200 g of steel balls in a 100 mL steel sealed can, and maintaining a vacuum state in the sealed can;

The flame retardant has good dispersibility in both polar and non-polar solvents, solubility in deionized water is about 0.8 mg/mL, solubility in dimethylformamide is about 1.0 mg/mL, in chloroform. The solubility in the solution is 0.95 mg/mL, the solubility in tetrahydrofuran is 0.92 mg/mL, the solubility in xylene is 0.90 mg/mL, and the flame retardant particle size is small and the distribution is relatively uniform, about 50-200 nm.

The flame retardant effect of the flame retardant is tested as follows:

The composite flame retardant is mixed with isotactic polypropylene to obtain a master batch, and the composite flame retardant is mixed with nylon 66 to obtain a master batch, and the flame retardant test strip is formed by an injection molding machine to obtain the composite resistor. The compatibility of the fuel in the resin is poor, and the obtained spline mechanical properties are brittle. In parts by weight of 24 parts in polypropylene and 20 parts by weight in nylon 66, the prepared composite material can achieve a flame retardance of 94UV-0, but a large amount of pungent odor is formed upon burning.

It can be seen that when red phosphorus is used as the flame retardant alone, the obtained composite material has poor mechanical properties, and although it has a good flame retarding effect, the smoke suppressing effect is poor, and toxic gas is released.

It is apparent that the above-described embodiments of the present invention are merely illustrative of the present invention and are not intended to limit the embodiments of the present invention, and those skilled in the art can also make the above description. It is to be understood that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

A high-efficiency halogen-free composite flame retardant characterized by comprising: the following parts by weight of raw materials:

100 parts of graphite materials;

Phosphorus flame retardant 50-600 parts.
The high-efficiency halogen-free composite flame retardant according to claim 1, which is composed of the following raw materials by weight:

100 parts of graphite materials;

Phosphorus flame retardants 50 to 390 parts.
The high-efficiency halogen-free composite flame retardant according to any one of claims 1 or 2, wherein the graphite material is selected from the group consisting of flaky graphite, massive graphite, amorphous graphite, artificial graphite, and expanded graphite. And one or more of the above various types of graphite oxides; the phosphorus flame retardant is selected from the group consisting of red phosphorus, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, polyphosphoric acid amine, phosphorus amine, trihydroxy phosphate, and alkane Phosphate, aryl phosphate, cyclic phosphate, triphenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, trimethyl phosphite, triethyl phosphite One or more of tributyl phosphite, trioctyl phosphite, triphenyl phosphite, organic phosphorus salt, phosphorus heterocyclic compound, polymer phosphorus (phosphonate) and organic phosphinic acid metal salt .
The high-efficiency halogen-free composite flame retardant according to claim 3, wherein the graphite-based material is preferably expanded graphite or flaky graphite; and the phosphorus-based flame retardant is preferably red phosphorus.
The high-efficiency halogen-free composite flame retardant according to any one of claims 1 or 2, wherein the composite flame retardant comprises graphene, phosphorylated graphene, graphene oxide, phosphorylated graphite, and graphite oxide. Two or more of graphite, phosphorus flame retardant, phosphorus pentoxide and elemental phosphorus.
The high-efficiency halogen-free composite flame retardant according to any one of claims 1 or 2, wherein the composite flame retardant has a morphology of a two-dimensional sheet-like structure and a mixture of nanoparticles, and a two-dimensional sheet shape. The structure size is 50 nm to 50 μm, the particle size is 10 nm to 1 μm, the solubility of the composite flame retardant in deionized water is 0.15-0.9 mg/mL; the solubility of the composite flame retardant in dimethylformamide is 0.2～1.2 mg/mL; the solubility of the composite flame retardant in chloroform is 0.05-0.85 mg/mL; the solubility of the composite flame retardant in tetrahydrofuran is 0.05-0.80 mg/mL; The solubility of the agent in xylene is 0.02 to 0.75 mg/mL.
The method for preparing a high-efficiency halogen-free composite flame retardant according to claim 1, comprising the steps of:

1) According to 100 parts by weight of the graphite material, 50 to 600 parts of the phosphorus flame retardant, and 10 to 5000 parts of the steel ball are placed in the steel sealed can, and the sealed tank is kept in a vacuum or an inert gas state;

2) After ball milling for 1 to 72 hours at a ball milling speed of 20 to 750 rpm, the obtained powder is a halogen-free composite flame retardant.
The method for preparing a high-efficiency halogen-free composite flame retardant according to claim 7, wherein in the step 1), the steel ball has a diameter of 2 to 130 mm, and the steel sealed can has a volume of 0.05 to 1000 L.
The method for preparing a high-efficiency halogen-free composite flame retardant according to claim 8, wherein in the step 1), 100 parts by weight of the graphite-based material, 50-600 parts of the phosphorus-based flame retardant, and 1000 balls of the steel ball are used. 1500 parts placed in steel In the sealed can; the steel ball has a diameter of 4 to 6 mm.
The method for preparing a high-efficiency halogen-free composite flame retardant according to claim 7, wherein in the step 2), the ball milling speed is 400 to 500 rpm, and the ball milling time is 12 to 48 hours.