Characteristics and Development Status of Intumescent Fire-retardant Coatings

The fireproof mechanism of the intumescent fireproof paint is that when the fireproof paint finish layer is exposed to flame, the foaming component in the paint film is thermally decomposed to form a heat-insulating spongy foam layer, thereby preventing flame propagation. The fire-retardant additives in paints are mainly foaming components, including carbon sources, foaming agents and organic nitrogen compounds, which can be used in combination. In the composition of non-intumescent fire-retardant paint must contain flame-retardant (fire-retardant), such as phosphorus-containing, halogen-containing organic substances (such as decabromodiphenyl ether), sodium borate, antimony trioxide and so on. Sodium borate is particularly suitable for use as a flame retardant for vinyl acetate-based emulsions. The amount of sodium borate is preferably 10% to 10%, preferably 40% to 60% of the polymer. The antimony trioxide itself is not very flame-retardant, but when it is in the initial stage of combustion, it can be born with antimony trichloride. For example, in the case of chlorinated paraffin, superior flame-retardant capability is exhibited. In order to obtain excellent fire-retardant performance, in addition to adding fire retardant urgency, the choice of base material is also very important. Because halogens (generally chlorine and bromine) and phosphorus are very effective in improving fire resistance, it is best to use binders with these elements. For example, vinyl chloride or vinylidene chloride copolymer emulsions or chlorinated rubber emulsions are the most preferred binders. In addition, trimethyl phosphonate and beta-trichloroethylene phosphate are selected as flame retardant plasticizers.

Before the middle of the 20th century, most of the decorative fireproof paints in China were inorganic fireproof paints, and their fireproof effects and physical and chemical properties were not ideal, which limited their popularization and application. It was not until the late 1970s that the country started to conduct research on organic-intumescent fire-retardant paints. The Sichuan Fire Research Institute of the Ministry of Public Security took the lead in introducing the B60-2 Intumescent Acrylic Latex fire retardant paint, using acrylic and partial chlorine mixed milk as the base material, and the compound containing PNC-Cl as an intumescent flame retardant. The fire-retardant performance of the coating reaches one level, and the physical and chemical mechanical performance is also ideal. In the 1980s, A60-1 modified amino-intumescent fire retardant varnish and PC60-1 latex veneer fire retardant paint were introduced, and successfully applied in many important projects. Since 1985, China's fire-retardant paint has entered a stage of vigorous development and serialization and standardization. The types, production and application scope of fire-retardant paints, and the number and distribution of production enterprises have made great progress. Simultaneously, product standards and tests have been formulated. Method standard. In 1989, Tianjin Fire Science Research Institute developed the FSF-1 water-based intumescent fire-retardant paint. The base material was a modified amino resin/acrylic acid copolymer and a polyvinyl acetate emulsion composite base material. The ammonium polyphosphate and ammonium phosphate were selected. , Melamine flame retardant fire-retardant system, its fire-retardant and flame-retardant and non-toxic, can be used for wood and steel fire protection and decoration; at the same time, the Shanghai Fire Research Institute of the room temperature fast drying A60-KG new amino-intumescent fire-retardant paint , Without acid catalysis, cross-linked and cured film can be formed at room temperature, and the purpose of rapid self-drying at room temperature can be achieved. The Ministry of Public Security Sichuan Fire Research Institute continued in 1996 to introduce serialized fire-retardant paints such as B6022 wood-based latex intumescent fire-retardant paint and PC6021 intumescent latex fire-retardant paint. At the beginning of the 21st century, the Shanghai Fire Science Research Institute of the Ministry of Public Security developed the S60-97 facing water-soluble fire retardant paint. The fire resistance of the paint is one grade, and the water resistance is up to 72 hours. Many other indicators are far from the technical requirements of GB15442011-1995 GB. , at the leading domestic level. Afterwards, Lu Jiulu and Xu Yaxian [3] and others developed water-based two-component intumescent fire-retardant varnish whose performance reached the first grade standard for decorative fire-proof paint. The paint is non-toxic, odorless, organic solvent free, and has good fireproof performance. This kind of fireproof paint can be stored and used in the range of -20-40°C. This is generally not possible with water-based coatings. In view of the performance of acrylic fire retardant paints in China and the toxicity of benzene solvents, Guo Tiejun and Shen Daming [4] developed a non-benzene solvent acrylic flame retardant paint with good performance and low cost. Special materials, fire performance reached two or even one level.

In recent years, expandable graphite (EG) has been widely used in fire-retardant paints as a good halogen-free physical intumescent flame retardant and synergist for expansion systems. Zhang Long, Li Guoxin [5-6] et al. It was found that the addition of EG greatly improved the fire resistance of the coating, but due to the color inferiority of graphite, the application of expandable graphite fire retardant paint was limited to some extent. In addition, some new intumescent materials are being valued and applied by people in the industry. Wang Jianguo [7] of Jiji University applies carbon nanotubes to fire-retardant paints to increase the expansion ratio of the coating and increase the denseness of the carbonized layer.

In addition, the application of new film-forming resins such as modified silicone resins [8-9] has greatly improved the thermal stability of fire-retardant coating materials. In recent years, China's decorative fireproof paint has developed rapidly. The types of fire-retardant paints are endless. The X-60, FR-60, E60-1, TXC-SM, WBM-01, and N-2 launched on the market are all representative water-soluble intumescent finishes. Paint, the performance of its products fully meet the GB12441-2005 veneer protective coating standard requirements, they have no pollution to the environment and fire and physical and chemical properties superior. In addition, the launch of CPL-AP90 water-based decorative fireproof paint, KY-BF-101 finish fireproof paint, carbonization volume is almost 0, showing excellent fire performance. With the continuous development of the real estate and other construction industries in China, the use of building decorative materials is also increasing. The research, popularization and application of China's facing fireproof paints are gradually entering a climax, and a high-quality, multi-variety, serialized product structure has been initially formed.