摘要： 以丙烯酸乳液为基体树脂，多聚磷酸铵、三聚氰胺和季戊四醇构成的膨胀型阻燃剂和阻燃协效剂为阻燃体系，制备了水性超薄膨胀型钢结构防火涂料，系统考察了防火涂料中阻燃剂和阻燃协效剂的含量对耐火性能的影响，通过正交实验对阻燃剂中各组分间的配比进行了优化。研究结果表明:多聚磷酸铵、三聚氰胺和季戊四醇按质量比5∶3∶2进行复配时，所得膨胀型阻燃剂具有最佳的阻燃效果;在丙烯酸乳液中添加该阻燃剂35.7%，阻燃协效剂5.1%制得的防火涂料，当涂层厚度为1.0mm时，耐火时间高达95.3min，明显高于国标规定的大于60min的标准;防火涂料中的阻燃协效剂在燃烧时参与炭层的生成，对炭层有增强作用。

关键词: 钢结构防火涂料 , 膨胀阻燃体系 , 协同效应 , 耐火性能 , 正交设计

Abstract: The water-based intumescent ultrathin fireproof coating for steel structure was prepared by u-sing acrylic latex as binder, ammonium polyphosphate (APP), melamine(MEL and pentaerythritol (PTH )as flame retardant and synergist flame retardant system. The effects of content of intumescent flame retardants and synergist on the fire-resisting performance of fireproof coating were systematically investiga-ted and mass ratio of components in intumescent flame retardant was also optimized by the orthogonal experi-mental design. The results showed that the intumescent flame retardant with the best flame-retardant prop-erty was obtained at the mass ratio of APP: MEL: PTH =5: 3: 2. When fireproof coating contained 35. 7 % of flame retardant and 5. 1% of synergist, its fire-retardant time reached 95.3 min with 1.0 mm of coating thickness, which is much higher than 60 min according to GB14907-2002. The synergist participated in the formation of char layers and greatly enhanced the strength of char layers.

Key words: fire-resistant coating for steel structure, intumescent flame retardant system, synergistic effect: fire-resisting performance, orthogonal design