Halogen-free flame-retardant system in which dialkyl mono-thiophosphate, inorganic phosphite and nitrogenous compound are synergetic and application thereof

Abstract

The invention discloses a halogen-free flame-retardant system in which dialkyl mono-thiophosphate, inorganic phosphite and nitrogenous compound are synergetic. The halogen-free flame-retardant systemcomprises 30%-90% of dialkyl mono-thiophosphate, 8%-30% of inorganic phosphite, 1%-30% of nitrogenous compound and 1%-10% of zinc-containing compound. The structural formula of the dialkyl mono-thiophosphate is shown as the formula (I) or (II), in the formula, R1 and R2 are independently selected from linear alkyl or branched alkyl, and the carbon number is 1-6; M is selected from Mg, Ca, Al, Sb,Sn, Ge, Ti, Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, K, H or NH4, and m is 1-4. The halogen-free flame-retardant system has the advantages that the system is high in flame retardance and free of migration,does not corrode equipment and the like and is well adapted to a glass fiber reinforced thermoplastic engineering plastic system, and halogen-free flame-retardant glass fiber reinforced thermoplasticengineering plastic with excellent comprehensive performance is obtained.

Description

technical field [0001] The invention relates to the technical field of flame retardants, in particular to a halogen-free flame retardant system in which dialkyl dithiophosphite, organic phosphite and nitrogen-containing compounds are synergistic and its use in the preparation of halogen-free flame retardant glass fiber reinforced Application of thermoplastic engineering plastics. Background technique [0002] Glass fiber reinforced thermoplastic engineering plastics are widely used in the field of electronic appliances because of their good rigidity and impact resistance, low warpage, high dimensional stability, good surface appearance, easy processing and recyclability. Applications in these fields require flame retardant materials, and thermoplastic engineering plastics are flammable materials. After compounding with glass fibers, glass fiber reinforced engineering plastics are easier to burn due to the wick effect of glass fibers. Therefore, when glass fiber reinforced e...

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Problems solved by technology

For red phosphorus, although its flame retardant effect is good, it faces two problems: one is the color of red phosphorus, which limits its application range, and is usually only used in black products; the other is that it is easy to generate phosphine during processing and other highly toxic substances, which bring environmental protection and safety problems, so red phosphorus is not the best choice for glass fiber reinforced thermoplastic engineering plastics

[0006] One is that the two components will react and decompose at high temperature to a certain extent, producing a small amount of acidic substances, which will corrode the metal parts of the processing equipment, and the parts need to be replaced after a certain period of time, which will increase and reduce the cost The problem of production efficiency; the second is that there is a certain precipitation of the nitrogen-containing compound MPP. During the injection molding process of the material, after injection molding a product with a certain modulus, there will be deposits on the mold. The existence of these deposits will affect the appearance of the product. This requires shutdown to clean the mold, which will also reduce production efficiency. At the same time, this precipitation will also cause the flame retardant to migrate to the surface of the product, resulting in uneven distribution and loss of the flame retardant, which will eventually cause the flame retardant of the material to fail, posing a safety hazard; The third is that the addition amount is large, which has a great influence on the mechanical properties of the material

[0007] In general, the flame retardant systems currently used in glass fiber reinforced thermoplastic engineering plastics have problems such as color, generation of toxic gases, easy precipitation, corrosion, and reduced mechanical properties of materials. lead to increased costs, reduced efficiency, etc.

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