Fireproof coating

Abstract

The invention relates to a fireproof coating. The fireproof coating comprises the following components in percentage by weight: 40-70% of an aqueous resin emulsion, 5-20% of modified expanded vermiculite, 10-30% of coating additive and other fillers, and 10-30% of water. The modified expanded vermiculite is prepared by the following steps: (1) carrying out incomplete expansion calcination on vermiculite: namely removing impurities from a vermiculite raw material, putting the vermiculite raw material into a rotary kiln, heating and expanding the vermiculite raw material, and carrying out discharging to obtain incompletely expanded vermiculite with a bulk density of 1000-1200 kg / m<3>; (2) adding the incompletely expanded vermiculite into a solvent, carrying out full stirring and ultrasonic dispersing to obtain a vermiculite suspension, adding the suspension and a carbon-forming catalyst ammonium polyphosphate into a closed reaction vessel, carrying out heating to 120-180 DEG C, carryingout stirring at a high speed, and preserving heat to obtain a suspension; (3) adding a fireproof modifier into the suspension obtained in the step (2) at normal temperature, and carrying out ultrasonic dispersion, wherein the fireproof modifier consists of a low-molecular carbon source and a foaming agent; and (4) performing centrifugal separation on the solution obtained in the step (3), and performing primary drying on the precipitate to obtain the fireproof expanded vermiculite. The fireproof coating has good fireproof performance and smoke suppression performance.

Description

technical field [0001] The invention relates to a fireproof coating, and specifically discloses an expansion type fireproof coating using fireproof vermiculite as a functional filler. Background technique [0002] Intumescent fireproof coatings are mainly used for fireproofing steel structures. The development of economy and society has promoted the development of the construction industry. Large-scale buildings such as exhibition halls, terminal buildings, large shopping malls, stadiums, high-end hotels and industrial plants are increasing, and are moving towards Large and beautiful, the main load-bearing components are mostly steel structures. [0003] For this reason, the fire protection of steel structures has attracted more and more attention. Although steel is a non-combustible material, its fire resistance is far worse than that of masonry structures and reinforced concrete structures. As the temperature increases, the mechanical strength of steel will decrease. Whe...

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Problems solved by technology

[0006] In the prior art, a series of attempts have been made to modify vermiculite to obtain higher performance. For example, a Chinese invention patent with a notification number of 100404612 discloses a "expanded vermiculite / potassium polyacrylate-acrylamide super absorbent Composite material preparation method", this method directly uses expanded vermiculite as raw material, and prepares super water-absorbent composite material through graft copolymerization of potassium acrylate and acrylamide monomer; this method uses expanded vermiculite at normal temperature as raw material and Combining organic matter, the prepared material has the characteristics of oleophobic and hydrophilic, and cannot be used in the field of hydrophobic materials

The Chinese invention patent application with the notification number CN1800072A discloses a "dry method for rapidly preparing intercalated vermiculite". According to a certain ratio, the quaternary ammonium salt intercalation vermiculite is directly synthesized in a torque rheometer at 100-180 ℃; this method directly modifies the unexpanded vermiculite raw material, and the product density is relatively high. , carriers and organic composite fillers and other fields are limited

[0007] However, the use of vermiculite as a fireproof functional filler in coatings or fireproof boards is just adding expanded vermiculite directly or using it together with other fireproof coatings such as intumescent flame retardant systems and halogen-containing flame retardant systems. Research on fire protection modification of

Shijiazhuang Yichen Fireproof and Thermal Insulation Material Co., Ltd. has carried out a series of researches and attempts. Among them, CN109321021A uses a fireproof modifier composed of a low-molecular carbon source, a carbon-forming catalyst and a foaming agent to treat incompletely expanded vermiculite. Improvement has significantly improved the fireproof effect of vermiculite and conventional fireproofing agents, but it has been found in actual use that if ammonium polyphosphate is used as the char-forming catalyst, the fireproof effect of the modified expanded vermiculite is obviously not as good as that of ammonium dihydrogen phosphate, ammonium dihydrogen phosphate, Expanded vermiculite with catalysts such as ammonium metaphosphate, the specific reason is unknown

But as we all know, the flame retardant effect of ammonium polyphosphate (APP) is the same as that of other ammonium phosphate salts, but there are no problems such as poor water resistance and easy recrystallization of other ammonium phosphate salts. Due to its good thermal stability, the amount of P and N contained Higher, low water solubility, no moisture absorption and other advantages, ammonium polyphosphate has been widely used in fireproof coatings, especially ammonium polyphosphate also has the advantage of low cost, for the current market competition is fierce, cost control has become the key to the survival of enterprises , therefore, the limitation of the use of ammonium polyphosphate in the above-mentioned technical solutions makes the production technology urgently need to be improved.

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