Flame Retardant Types and Applications in China

The type and application of flame-retardant bundles in our circle, Lianyungang Seawater Chemical Plant, Zhang Gengzhu, Liu Maochun, An Qiutui, Li Hongnian, and the application range are limited. This article outlines the simple preparation methods of flame retardants and the application fields of different flame retardants.

Raw materials such as chemical fiber are widely used in modernization. These polymeric materials are flammable or flammable, and when they are burned, they generate a lot of smoke and harmful gases, causing serious economic losses. According to information, the annual loss of fire in the world is equivalent to that of EU 00. For this reason, the incombustibility of chemical building materials with non-flammable and low toxicity has attracted people's attention, which will promote the development of flame retardant science.

1 Current situation of China's flame retardant industry In the late 1950s, some industrialized countries used flame retardants extensively in industrial production. Because the government's relevant agencies attach sufficient importance to fire protection, various fire prevention laws and regulations have been introduced to promote the The rapid development of flame retardants and flame retardant materials. China's flame-retardant science and technology started relatively late. After the reform and opening up, it has gradually received attention from relevant parties. Although this has promoted the development of China's flame retardant science, it cannot meet the needs of the development of the national economy. Mainly, there are fewer and fewer types of flame retardants, and the scope of application is limited. Many of them are duplicate products, such as the oversupply of bromine ether and bromine bisphenol 4; due to the lack of process technology, the quality of some products cannot meet the requirements, and some flame retardants need to be imported, such as decabromodiphenyl ether bromophthalic anhydride. Wait.

2 domestic flame retardant profile In the polymer according to the right mix plus flame retardant and synergist, the molding process can achieve the purpose of flame-retardant. At present, the flame retardants produced in China are mainly organic and inorganic substances such as phosphorous halogenated borax and cesium, which are divided into additive reaction type and auxiliary flame retardant.

Additive flame retardants usually incorporate the flame retardant in the polymer, making it a flame retardant material. This type of flame retardant is mainly an inorganic flame retardant deuterated compound red phosphorus hydroxide aluminum hydroxide zinc borate magnesium hydroxide; organic flame retardant phosphate ester cresyl phosphate ester phenyl phosphate butyl phosphate etc., halogen compound ethyl bromide Bromobutane hexabromocyclodecane hexabromobenzene chlorinated paraffin bromobisphenol into bis 2,3 bromopropyl ether 2,3 bromopropyl isocyanate decabromodiphenyl ether.

A reactive flame retardant is a flame retardant that chemically reacts with a polymer to perform molecular bonding. The main types of this type are bromobenzoic anhydride chlorobenzoic anhydride bromobisphenol.

Auxiliary flame retardants can be combined with phosphorus or halogen flame retardants to provide flame retardant effect. For example, 51203 is mainly used as a synergist, and it plays a flame-retardant role in the product after being synthesized with a halogen compound. Due to the addition of 503, it can replace some of the expensive flame retardants.

2.1 Inorganic Flame Retardants Inorganic flame retardants have the characteristics of good thermal stability and low cost, but they have a large amount of additives and affect the physical properties of the polymer.

2.1.1 Aluminium hydroxide Aluminium hydroxide is abbreviated as a substitute type of inorganic flame retardant. It is non-toxic and is a white monoclinic crystal. Adding aluminum hydroxide to the plastic can promote the carbonization of the polymer during combustion and reduce the amount of smoke emitted by the plastic during combustion.

Production methods Aluminum sulfate or aluminum chloride is added to ammonium hydroxide to precipitate, and the aluminum hydroxide is obtained by filtration, washing and drying. 2.1.2 Magnesium hydroxide Magnesium hydroxide is a kind of flame-retardant filler. It mainly plays the role of flame retardant and smoke elimination in plastics. It is a kind of white square crystal.

Production Method Flame Retardant or Flame Retardant Filler Magnesium Hydroxide Available ± ± Magnesium Chloride Preparation. Magnesium chloride was dissolved in water, ammonium hydroxide was added thereto for precipitation, and the product was obtained by filtering and washing with water.

Antimony oxide antimony oxide itself can not play a significant role in flame retardant, can be used together with halogen flame retardant to help flame retardant effect. Antimony oxide is a white powder that is insoluble in water and nitric acid.

Most of the production methods use the wet production process, that is, the sulfur yttrium ore is leached with hydrochloric acid to produce yttrium oxide, and then the finished product is obtained by the hydrolysis method.

Boric Acid Boric Acid Zinc Borate, abbreviated as 8, is a flame retardant with good thermal stability. From an economic point of view, it can partially replace the more expensive yttrium oxide, which is a kind of non-toxic and odorless white powder that loses its crystallinity in excess of 300 弋. water.

Production method: The borax zinc sulfate and the zinc oxide are stirred and reacted in an aqueous solution of 70 or more. Under the action of the seed crystal, a crystalline zinc borate hydrate is obtained, which is filtered, washed and dried to obtain a finished product.

2.2 Brominated Flame Retardants Brominated flame retardants are the best organic flame retardants with the largest output in China, second only to phosphate esters. In recent years, domestic brominated flame retardants have greatly improved in terms of the application range of product quality and quantity technology.

Ethyl bromide 0228, ethyl bromide is a white or light yellow oily, strongly refractive liquid.

The production method will add bromine to the reactor, and then gradually pass through the purified gamma gas, until the reaction solution turns from dark brown to yellow gray, that is, the reaction is completed. After the alkali washing, the finished product can be used as an additive flame retardant. .

22.2 Hexabromocyclodecane, 288犷6 hexabromocyclodecane, abbreviated 00, is a white crystalline powder.

The production method uses butene to obtain the 5,9 ring ten carbonene by the reaction of butyl titanate ethylaluminum chloride, and reacts with bromine, and is obtained after the post-treatment drying.

Abbreviated as 18 people, it is a multi-purpose flame retardant. It can be used as a reactive flame retardant or as an additive flame retardant. It is currently the largest brominated flame retardant in domestic production and is a kind of white powder.

The production method dissolves bisphenol in ethanol solution, adds bromination and bromination, controls the temperature below 25, and adds bromine to pass through 012 so that the reaction produces 1 and 2 is oxidized into 2 and continues to participate in the reaction. The by-products are also easily removed, filtered, washed and dried to obtain finished products. Different preparation processes are mainly based on different solvent choices.

Bromine o-benzoic anhydride, referred to as bromophthalic anhydride 8 people, is an important reactive flame retardant. It can also be used as an additive flame retardant. It is a white or light grayish white powder with excellent thermal stability and light stability.

Production methods Currently, phthalic anhydride is mainly dissolved in oleum with extremely high concentration of phthalic anhydride, and bromine is added dropwise in batches under the action of a small amount of iron iodide catalyst. The reaction proceeds smoothly under stirring conditions, and the finished product is washed.

In the production process, waste acid recycling is an important lesson that is difficult to solve.

Hexabromobenzene is a versatile flame retardant, white or light yellow powder.

The production method uses excessive bromine as a solvent for bromination, drops benzene into human bromine solution, and uses aluminum powder or iron powder as a catalyst. When the benzene is added, the bromine is boiled and refluxed for a fixed time, and the bromine is distilled out after the reaction is completed. Neutralization with lye, filtered and washed to obtain the finished product.

2.2.62, 3 bromopropyl isocyanate, abbreviated as 18, is a white crystalline powdered nitrogen-containing additive flame retardant.

The production method is that polyisocyanic acid and allyl chloride are used in the presence of sodium hydroxide to prepare propenyl isocyanate using copper salt as a catalyst, and then the compound is dissolved in an organic solvent for bromination, and the filtered methanol is washed and then distilled water is used. The washing is dried at 80 to obtain the finished product.

Bromobisphenol The human 2,3 bromopropyl ether, abbreviated to bromoether 800, is a white or light yellow powder. It is a rare chemical compound containing both aromatic bromine and aliphatic bromine. This product has a large molecular weight and good compatibility with the resin and is an additive flame retardant.

The production of this product is carried out in two steps in the first step. The brominated bisphenol is etherified and condensed to obtain bromobisphenol bisallyl ether 0, that is, the milk 1 cadherin 1 method is used in the presence of alkali to use chloropropene and bromobisphenol. Human synthesis.

In the first step, from the electrophilic addition reaction between human and valence 2, decabromodiphenyl ether, abbreviated as 0800, is a kind of white powder with high bromine content and is a typical additive flame retardant.

The solvent method dissolves the phenyl ether in the solvent, adds the catalyst, and then adds the bromine to carry out the reaction. After the reaction, the product is filtered, washed and dried to obtain the finished product.

Excessive bromine excess bromine used as a solvent, the catalyst was first dissolved in bromine, bromine was added dropwise phenyl ether reaction, the excess bromine distilled off after the reaction, plus alkali washing and filtration to obtain the finished product.

2.3 Chlorine-based flame retardants 2.3.1 Chlorinated paraffins Chlorinated paraffin with a chlorine content of 70 is a kind of white powder. It is the earliest industrialized production and application of organic flame retardants in foreign countries.

The method of production will dissolve the paraffin after the introduction of chlorine. When the chlorine content reaches 50, the reactants will become viscous and chlorine gas will be difficult to pass through. After diluted with chlorinated carbon, the chlorine will continue to be passed. When the reaction is complete, the free chlorine and solvent of the hydrogen chloride will be eliminated. Remove the finished product.

2.3.2 Chlorobenzoic anhydride 014 Abbreviated as chlorophthalic anhydride, it is a white, odorless prismatic or needle-like crystal.

The main production method is that the phthalic anhydride is dissolved in the fuming acid, then the chlorine is reacted, and then the chlorobenzoic acid is heated to 98 dehydration.

2.4 Phosphorous Flame Retardants China's current production of phosphorus-based flame retardants has a relatively small number of applications. The first production of phosphate vinegar is mainly used as a plasticizer. Inorganic phosphorus flame retardants are mainly monomeric red phosphorus. Organic phosphorus flame retardants include halogenated phosphate esters and non-halogenated phosphate esters.

24.1 Halogen Phosphate Flame Retardants Halogen phosphate flame retardants have dual flame-retardant elements containing phosphorus and elemental, have excellent synergistic effect of flame retardant, and have plasticizing effect, low volatility and hydrolysis resistance.

Abbreviation 10 is a colorless or light yellow oily liquid that is a flame retardant plasticizer.

The production method is usually reacted with chlorophosphorous oxide and ethylene oxide, that is, the catalyst is added to the oxychloride, the ethylene oxide is esterified at 4550, and the ethylene oxide is removed to remove the excess ethylene oxide. And water vacuum dehydration products.

Abbreviated as colorless or light brown oily liquid, it has excellent light resistance and good compatibility.

Production method: Chloroxyphosphorus and propylene oxide are esterified under the action of a catalyst, and the final product is obtained through dehydration by neutralization and water washing.

It is a kind of light yellow transparent viscous liquid and it is a very good additive flame retardant.

The production method brominates allyl alcohol to 15 to form bromopropanol. Under the catalysis of water-free human 1013, bromopropanol and 0013 are heated in the benzene solution to about 40 times to produce a finished product.

2.4.2 Phosphate Flame Retardants Phosphate esters are used as plasticizers for plastics and as flame retardants. For example, butyl phosphate 18 octyl phosphate 1 phenyl phosphate 1, etc., has good heat resistance, not only makes the resin flame retardant, but also has plasticity.

It is usually prepared by reacting phosphorus oxychloride with phenols or alcohols.

3 Application of Flame Retardants Various flame retardants have different advantages and disadvantages, and their uses are not. Therefore, we must develop corresponding flame retardants for different flame retardant requirements.

3.1 The scope of application of flame retardants The scope of application of several major flame retardants currently developed in the country is described below.

3.1.1 Additive flame retardant Bromoethane Bromobutane is mainly used in polystyrene foamed plastic polyvinyl chloride.

2,3 bromopropyl isocyanate is mainly used for polyethylene polypropylene, polystyrene, polymethyl methacrylate, polyurethane foam, polycarbonate and polyester.

The sharp brominated benzene can be used for polystyrene into 83 polypropylene polyethylene epoxy resin and unsaturated polyester.

Decabromodiphenyl ether has high bromine content, good thermal stability, and high flame retardant efficiency. It is widely used in the processing of polystyrene 83 Polyolefin Polyamide and other thermoplastic plastics. It can also be used in epoxy resin phenolic resin unsaturated polyester, etc. Flame-retardant processing of thermosetting resins is called all-round flame retardant.

Chlorinated paraffin waxes and thorium oxides are used in polyethylene polystyrene and synthetic rubbers.

The self-phosphoryl ester flame retardant has excellent low-temperature characteristics and light resistance, and has good compatibility with the resin, and is mainly used for cellulose acetate nitrocellulose phenolic resin polystyrene polyvinyl chloride and the like.

Phosphate flame retardants are liquids, which make up for the insufficiency of most solid flame retardants. For example, liquid plastic flame retardants must be used for transparent or colored synthetic fibers. Mainly used for PVC and other polyethylene.

Aluminum hydroxide is mainly used for epoxy resin unsaturated polyester polyolefins and polystyrene.

Magnesium hydroxide is used for polyethylene polypropylene polystyrene and 83 resin.

Zinc borate is used in paints, polyesters, polyolefins, polystyrene, polyurethane, neoprene, etc.

3.1.2 Reactive Flame Retardant The bromobisphenols are used as reactive flame retardants for epoxy resins and polycarbonates. They can also be used as additive flame-retardant additives such as 88 Impact Resistant Polystyrene Resin 3 and phenolic resins. Agent.

Bromophthalic anhydride can be used as a flame retardant for the polyester unsaturated polyester epoxy resin, and it can also be used as an additive flame retardant for polyethylene polypropylene polystyrene and human 83 resin.

Suitable flame retardants for different polymers are listed in 1.

3.2 Application of Flame Retardant in Polymeric Materials Domestic flame retardants have also been used in chemical building materials products; flame-retardant fabrics are mainly polypropylene fibers; flame-retardant plastic and rubber products have made great progress in recent years, mainly plastic pipe plate televisions Outer casing electrical and electronic components and coal mines use fake top net air duct rubber belt. This type of intumescent fire-retardant coating has long been studied successfully, and it has played a good role in the fire protection of building materials such as structural plastics and rubber-board pipeline cables. mouth