With the organic synthesis of the extensive application of polymer materials and the rapid development of society, Intensification of the urban population, residential and office buildings and commercial and public buildings as well as the intensive, high-level, in social life and in the field of production factors and the risk of fire in the frequency has increased.,States in recent years the losses caused by the fire upward trend, Wide in the unburned,  the development and application of flame retardant has been drawing more and more people's attention,flame retarment is an important  promoter of polymer material, can make synthetic materials with flame retardant, and Smoke and sexual self-extinguishing. According to there are difference between filler and flame retardant ,it can be divided into Add-reactive flame retardant,Add-flame retardant in plastics, and other molding process, the physical mixture to spread the flame retardant plastic products, It is generally solid or liquid. Reactive flame retardant is through chemical reactions with polymer molecules to the main chain or branched-chain on the flame retardants. Add flame retardant mainly include antimony flame retardants, aluminum flame retardant, halogen flame retardant, phosphorus flame retardant, flame retardant, such as boron, Mainly reactive flame retardant epoxy resin intermediates, polycarbonate intermediates, polyester intermediates, in the rinse Mi from polyurethane flame retardant added the proportion of larger, particularly in the use of flame-retardant plastic .

   Antimony trioxide is an Add-flame retardant, Add antimony trioxide is a flame retardant, mainly for plastics (PVC, polyolefins, polyester), and flame-retardant textile fabric, but also can be used for canvas, paper, paints, coatings, such as the flame retardant agents and petrochemicals, synthetic fibres may also be used as a catalyst, such as rubber, timber fire retardant, enamel cover review of the industry, the electronics industry materials and so on, The antimony trioxide as flame-retardant additives,its particle size and morphology of synthetic material effect on the flame-retardant and  properties  is large. Size is an important indicator of antimony trioxide products, synthetic chemical fiber, textile products often require antimony trioxide flame retardant treatment of the particles in the nanometer size range, small size, to achieve the same flame-retardant effect of antimony trioxide also use the less, and will not be obstructive spinneret holes, which is the key flame retardant textiles. China antimony reserves occupy first place in the world, every year a large number of antimony oxide or antimony ingot exports. But China's antimony oxide production technology is backworld, and products can not meet the domestic textile industry in the refinement of demand, (Ultra, high-white, small size and uniform distribution), the production sector by using only expensive imported Western countries Processing products to Western industrial countries to earn a lot of secondary economic benefits. Therefore, changing the backwardness of China's antimony oxide production technology, research and development of ultra-fine white high degree of high purity antimony oxide products, this has a wide range of social and economic benefits.

 

This study used three different types of wet chemical methods on the preparation of antimony trioxide powder, antimony trioxide flame retardant mechanism of the preliminary analysis, and its fire-retardant properties were studied.

 

1.Preparation of antimony trioxide

1.1 Preparation of antimony trioxide industrial methods

Under the conditions of heating metal and oxygen reaction

   4Sb+3O₂→2Sb₂O₃

Roasting three of antimony sulfide minerals law:

2Sb₂S₃+9O2→2Sb₂O₃+6SO₂

Antimony trichloride two hydrolysis method:

2SbC_l3+H₂O→2Sb₂O₃+6HCl

 

Its process:

Wet with acid (sulfuric acid and more) directly from the antimony concentrate production antimony oxide law:

Its process:

Other: "Electrolytic Chlorination Law."

Several methods of the above, the former is a dry; after three are wet. At present more domestic use is wet, the new method of antimony trioxide and also plasma gel precipitation method,

the greatest disadvantage of These production is high impurity content, low degree white powder is unevenly distributed, the intensification of production can not satisfy the requirements.

1.2The work of the ultra-fine powder of antimony trioxide method:

SbCl3 work for the raw materials used, respectively precipitation method, sol - gel prepared by antimony trioxide ultrafine particles. Chemicals and reagents used are Bansichun using A, B, C three different wet chemical methods of antimony trioxide powder. A method is SbCl3 powder dissolved in concentrated hydrochloric acid, magnetic stirring completely dissolved, the solution to the slow dropping deionized water, dripping while stirring at the beginning of the reaction solution for the stability of yellow, white Finally a small block Precipitation generation, the last white precipitate more and more, and in-Shen. Rinse precipitation, and the dumping On several occasions to remove impurities free ion. Sediments and then repeatedly boiled to the ammonia chloride, and then dumping water out several times, washing filtration, drying sediments, that is, In the antimony trioxide powder. Method B is SbCl3 powder dissolved in ethanol, magnetic stirring fully dissolved, the solution to ease
Slow trickle-down deionized water, and continue to stir-white latex that is in the precipitation. Analysis of water several times before dumping, and filter washing, drying after a antimony trioxide powder. Approach C is SbCl3 powder into a certain proportion of the mixture of ethanol and benzene, stirring fully dissolved in the transparent liquid antimony alcohol, adding to the solution suitable isopropanol, Aging reaction more thoroughly before adding a small amount of cationic surfactant, and dropping ammonia, so that the occurrence of the hydrolysis reaction be rubbery sedimentation, filtration washing several times after drying, a white antimony trioxide ultrafine powder.

 

2.Mechanism of antimony trioxide flame retardant

A clear mechanism of antimony trioxide flame retardant, it first has to understand the combustion conditions and plastic process. Burning plastic three conditions, namely, from the plastic itself flammable gases, oxygen and the outside heat source.

Plastic combustion process for the main reaction:

HO.+CO→CO2+H.-ΔH　

H.+O2→HO.+O.　(Disproportionation reaction)

From the above that, in order to prevent the plastic burning, and the basic approach is to curb the occurrence of flammable gases in the air and isolation of oxygen.

 3.Antimony trioxide flame retardant characteristics of the experimental analysis

Flame Retardant performance test methods can be broadly divided into two categories [11]: an experimental method for combustion, such as vertical combustion method, the level of combustion, burning 45 ° angle, the length of the flue, disk , the United States, Britain, West Germany and other countries have formed their own set of test standards; another is used mainly to study the mechanism of combustion testing methods, such as oxygen index method, thermal analysis, calorimetry, scanning electron microscopy etc.. The more commonly used method of aerobic index, thermal analysis, paper, calorimetry. The major work by thermal analysis and cotton fabric vertical combustion.

4.Conclusion