Background and overview[1][2]
Tris(2-chloropropyl)phosphate, also known as tris(chloroisopropyl)phosphate, or TCPP, has three main isomers, namely: tris(1-chloro-2-phosphate) Propyl) ester, di(2-chloro-2-propyl)(1-chloro-2-propyl) phosphate, di(1-chloro-2-propyl)(2-chloropropyl) phosphate, The first isomer is the main component and plays a key role in the flame retardant performance, so its content directly affects the flame retardant performance of the product; the second and third isomers are minor components. point. It is an additive low molecular weight halogen phosphorus flame retardant with good flame retardant effect. It is mainly used in the flame retardancy of polyvinyl chloride, polystyrene, phenolic resin, acrylic resin, rubber and coatings. It is also widely used. In polyurethane soft foam, hard foam and plastic products. It is also a good plasticizer.
Preparation[1]
The current preparation method of TCPP is to react phosphorus oxychloride with propylene oxide under the catalysis of Lewis acid as a catalyst to obtain crude TCPP. The resulting product has dark color, high color number, unstable acid value, The purity is not high, and the content of isomers as secondary components is high, and aldehydes are also produced, causing the product to smell. Post-processing such as alkali washing, water washing, dehydration and filtration cannot effectively reduce the smell, which is serious. Affect product appearance and quality.
Phosphate ester flame retardants are the second largest variety of flame retardants in the world, with a global output value of approximately US$1.2 billion. Compared with other flame retardants, phosphate ester flame retardants have long-lasting flame retardant effects, good compatibility with polymer substrates, water resistance, weather resistance, heat resistance and migration resistance. They are indispensable in the field of polymer materials such as polyurethane. important position of substitution. With the increasing environmental protection requirements, the application scope of traditional brominated and other halogen flame retardants has been restricted to varying degrees. Phosphate ester flame retardants are environmentally friendly flame retardants, and their future market prospects are very promising.
The production process of phosphate ester flame retardants is mainly divided into two processes: esterification reaction and post-treatment. At present, in the post-treatment process of phosphate ester products, the traditional method includes the following steps: pickling, alkali washing, water washing, dehydration and filtration. The production method used is the intermittent operation of pickling kettle, alkali washing kettle and water washing kettle. . The traditional post-treatment method not only has a small device capacity, but also has unstable product quality. More importantly, because the phosphate ester itself is hydrolyzable, the product will be exposed to acid, alkali and water for too long during the post-treatment process, which will affect the product. yield.
The present invention provides a method for preparing high-purity phosphate flame retardant tris(2-chloropropyl)phosphate, which enables faster reaction speed, shorter reaction time, automatic control of reaction endpoints, and can improve products The proportion of the main components in the TCPP product obtained has higher purity, lower acid value, lower color number, better flame retardant effect, higher stability, and longer storage time. The purity of the obtained phosphate ester flame retardant TCPP above 95%.
To this end, the present invention adopts the following technical solution: a preparation method of high-purity phosphate ester flame retardant tris(2-chloropropyl)phosphate, which includes the following steps: adding a catalyst and additive, and then slowly add propylene oxide dropwise. After the reaction, the crude product tris(2-chloropropyl)phosphate is obtained. The product tris(2-chloropropyl)phosphate is obtained by removing low boiling point substances, alkali washing, water washing, distillation dehydration and filtration. propyl) ester; the reaction temperature range is 20-60°C in the early stage of the reaction, the reaction temperature range is 40-80°C in the middle stage of the reaction, and the reaction temperature range is 40-100°C in the late stage of the reaction; during the reaction process, the reaction temperature ranges from the early stage to the late stage of the reaction. In each stage, the reaction temperature of the latter stage is not lower than the reaction temperature of the previous stage, achieving stepwise temperature rise; the reaction end point is automatically controlled by controlling the temperature drop rate or cooling medium flow rate.
The present invention can significantly increase the proportion of main components in the product by controlling the dosage of catalysts and auxiliaries, stepwise temperature control, automatic control of reaction end points and other technical means. The present invention can make the main components The content is increased to 82-85% (the content obtained by existing methods is usually below 75%); at the same time, the proportion of secondary components of the product can be significantly reduced, and the content of the second isomer is controlled at around 15% ( The content obtained by existing methods is20-25%), and the content of the third isomer is controlled at about 1.5% (the content obtained by the existing method is 2.5-3.0%). The reaction speed of the present invention is faster, the reaction time is shorter, the TCPP content containing three isomers is more than 98%, and the unit consumption of raw materials is lower. The present invention removes low-boiling point substances before alkali washing, removes unreacted propylene oxide and low-boiling point by-products, and then goes through other post-processing steps to make the purity of TCPP above 95%.
Apply [2]
Tris(2-chloropropyl)phosphate can be used to prepare a highly flame retardant coating. Acrylic paint has high hardness, excellent gloss and chemical resistance after film formation, and is low cost. It is widely used in the automotive, construction and furniture industries. Traditional solvent-based acrylic paints release a large amount of volatile organic compounds during the film formation process, causing pollution to the environment. However, water-based acrylic coatings still have many shortcomings, such as low hardness of the coating film, not very good wear resistance, not very ideal flame retardant properties, etc., which hinder its development.
The present invention proposes a highly flame-retardant coating, which has good water resistance and wear resistance, excellent flame retardant performance and long service life. CN2016107 Tosoh 35568.7 proposes a high flame retardant coating. The raw materials include: 100 parts by weight of water-based acrylic emulsion, 5-20 parts of water-based polyurethane resin, 5-15 parts of aluminum sol, 2-10 parts of epoxy resin, 2-10 parts of polydimethylsiloxane, 2-5 parts of zinc oxide, 2-10 parts of hollow glass beads, 1-5 parts of nano-zirconia, 1-5 parts of montmorillonite, 1-5 parts of nano-silica 5 parts, 3-11 parts of film-forming additives, 0.2-1 parts of defoaming agent, 0.1-0.8 parts of leveling agent, 0.5-1.2 parts of wetting agent, 3-12 parts of flame retardant, 5-15 parts of water; Wherein, the flame retardant is composed of boron oxide, dimethyl methyl phosphonate, phosphorus pentoxide, tris (2-chloropropyl) phosphate, amidinourea phosphate, ammonium polyphosphate, pentaerythritol, melamine, hexamethyl It is a mixture of base disiloxane, and boron oxide, dimethyl methyl phosphonate, phosphorus pentoxide, tris (2-chloropropyl) phosphate, amidinourea phosphate, ammonium polyphosphate, pentaerythritol, melamine, The weight ratio of hexamethyldisiloxane is 1-5:2-8:2-10:1-5:5-20:3-15:2-15:2-10:1-5.
The high flame-retardant coating of the present invention can be prepared according to the conventional acrylic coating preparation process. Among the raw materials of the high flame-retardant coating of the present invention, water-based acrylate emulsion is used as the main material, and water-based polyurethane, aluminum sol, epoxy resin and polydimethylsiloxane are added to modify it, thereby enhancing the properties of the paint. The adsorption force of the film to the surface of the substrate makes the adhesion of the paint film reach level 1, and at the same time, the resulting coating film has high tensile strength, good thermal stability, and excellent fire resistance; zinc oxide and hollow glass are added Microbeads, nano-zirconia, montmorillonite, and nano-silica are used as filler systems. By adjusting the proportion of each filler in the present invention, the hardness and thermal stability of the paint film are improved while maintaining excellent adhesion of the paint film. , wear resistance and flexibility;
Among the flame retardants, boron oxide, dimethyl methylphosphonate, phosphorus pentoxide, tris(2-chloropropyl)phosphate, amidinourea phosphate, ammonium polyphosphate, pentaerythritol, Melamine and hexamethyldisiloxane are used as raw materials to synergize the performance of each flame retardant, greatly reducing the heat release rate and total heat release of the paint film, increasing the mass fraction of the residue, and significantly extending the ignition time. It reduces the CO release rate, smoke release rate and total smoke release, and has very excellent flame retardant properties and smoke suppression properties. The flame retardant time of the resulting paint film can reach more than 15 minutes, and the high temperature resistance and flame retardant properties are significantly improved. At the same time, The water absorption rate of the paint film is reduced to less than 7.5%.
Main reference materials
[1] CN201610996871.2 Preparation method of high-purity phosphate flame retardant tris(2-chloropropyl)phosphate
[2] CN201610735568.7 A high flame retardant coating
