RU2250204C1 - Fireproofing coating - Google Patents

Abstract

FIELD: fireproofing coatings.

SUBSTANCE: invention relates to building materials and is intended for use when coating supporting and safety structures. Fireproofing coating contains 20 to 60% filler and 40 to 80% mineral binder, said filler being aluminum, iron, calcium, or magnesium hydroxide, or mixture of any of indicated hydroxides with particle size not larger than 100 μm and said binder being liquid glass or aqueous solution of sodium polyphosphate having density 1300-1400 kg/m³. Fireproofing ability of coating is caused by presence if significant quantity of bound water therein. Coating is characterized by lower heat conductivity at temperatures above 600°C.

EFFECT: enhanced high-temperature fireproofing ability.

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Description

The invention relates to building materials and is intended for application to load-bearing and enclosing structures, mainly metal, used indoors, in order to ensure fire resistance of building structures of buildings and structures.

Fireproof coatings for this purpose are known, for example, from RF patent No. 2133241 C 04 V 28/26, 1999; from the patent of the Russian Federation No. 2092463 C 04 B 28/26, 1997; author St. USSR No. 337528 C 04 V 28/26, 1970; RF patent No. 2132311 C 04 V 28/26, 1999 and others.

The closest analogue can be considered fire retardant coating according to the patent of the Russian Federation No. 2133241 C 04 V 28 / 26.1999. It contains two components: filler - minerals accompanying hydromica 23-44 wt.% And mineral binder (liquid glass 56-77 wt.%, Density 1460 kg / m ³ ), which are mixed before use.

The main disadvantage of this coating is its increased thermal conductivity at temperatures above 600 ° C, which is partially offset by an increase in the thickness of the coating. Increasing the thickness of the coating increases the load on the metal structure, increases the complexity and costs of fire-retardant work, increases the timing of their implementation.

The invention is aimed at obtaining a fire retardant coating with high performance properties, convenient in transportation and in use at the facility and applied with a minimum consumption.

The technical result, which is created by the invention, is to increase the fire-retardant properties of the coating by increasing its heat-insulating ability at temperatures above 600 ° C and while ensuring a decrease in the thickness of the applied coating.

This is achieved by the fact that the fire retardant coating contains aluminum, iron, or calcium, or magnesium hydroxide as a filler, or a mixture of any hydroxides of these metals with a particle size of not more than 100 μm, and liquid glass or an aqueous solution as a mineral binder sodium polyphosphate with a density of 1300-1400 kg / m ³ in the following ratio of components, wt.%:

specified filler 40-80

the specified mineral binder 20-60

With this composition provides a different, compared with the prototype, the mechanism of fire resistance of the protected surface. It is based on the presence of a significant amount of chemically bound water (hydroxyl groups) in the coating filler. Under the influence of high temperature, water is gradually released, preventing the surface of the protected structure from heating above 500 ° C. Moreover, the coating has lower thermal conductivity at temperatures above 600 ° C.

If the content of the specified metal metal hydroxide is less than 40 wt.%, There will be insufficient chemically bound water to exclude heating of the protected surface. When the hydroxide content of the indicated metal is more than 80 wt.%, The adhesion of the coating to the surface is reduced, the elasticity and paint properties of the coating are deteriorated.

It is understood that the patented coating in which the filler has the largest number of hydroxyl groups will have the highest fire resistance.

With an increase in the particle size of the filler over 100 μm, the specific surface decreases, the defectiveness of the structure decreases, and an increase in thermal conductivity at temperatures above 600 ° C due to radiation is observed.

When the density of the mineral binder is less than 1300 kg / m ³ , the filler separates when coating the protected surface.

The uneven distribution of filler particles increases the thermal conductivity of the coating at temperatures above 600 ° C.

When the density of the mineral binder is more than 1400 kg / m ³ , premature setting of the filler occurs without obtaining a homogeneous mixture.

The invention is illustrated by examples.

To obtain a fire retardant coating, the following components are used:

- filler in the form of a powder with a particle size of not more than 100 microns from:

aluminum hydroxide;

iron hydroxide;

calcium hydroxide;

magnesium hydroxide;

- liquid glass (mineral binder in the form of an aqueous solution with a density of 1300-1400 kg / m ³ ;

- sodium polyphosphate (mineral binder in the form of an aqueous solution with a density of 1300-1400 kg / m ³ ).

Hydroxide or a mixture of hydroxides of the indicated metals and mineral binder in the stated proportions are loaded into the mixing tank by weight, the mixture is thoroughly mixed, then the mixture is packaged in a sealed container.

The resulting two-component coating is ready for use, it can be transported to the place of use.

Fire-retardant coating can be applied to the protected surface using a brush, roller or mechanized method, the operational thickness of the coating does not exceed 5 mm (in the prototype 11 mm).

To compare the patented coating and the prototype for fire resistance, the coefficient of thermal conductivity was determined at 100 ° C, 600 ° C and 1100 ° C.

The compositions and properties of the coatings are shown in the table.

Temperature ° С Thermal conductivity coefficient (W / mK) Compositions 1 2 3 4 5 Analogue 100 0.18 0.20 0.19 0.20 0.21 0.11 600 0.21 0.24 0.23 0.24 0.24 0.22 1100 0.25 0.25 0.24 0.25 0.25 0.9

Composition No. 1, wt.%: 30 sodium polyphosphate;

70 magnesium hydroxide.

Composition No. 2, wt.%: 40 liquid glass;

60 iron hydroxide.

Composition No. 3, wt.%: 50 sodium polyphosphate;

50 aluminum hydroxide.

Composition No. 4, wt.%: 45 sodium polyphosphate;

55 calcium hydroxide.

Composition No. 5, wt.%: 30 calcium hydroxide;

30 aluminum hydroxide;

40 sodium polyphosphate.

Analog, wt.%: 45 liquid glass;

55 vermiculite ore.

As can be seen from the table, the patented fire-retardant coating has a significantly lower thermal conductivity at temperatures above 600 ° C, which makes it possible to use this coating with a much smaller thickness on the surface to be protected.

Reducing the thickness of the applied coating reduces the load on the metal structures of buildings and structures, reduces the complexity and costs of fireproofing, reduces the timing of their implementation. An important advantage of such a coating in comparison with the prototype is its readiness for use without the need for mixing the components before coating the protected surface.

Claims (1)

A fire retardant coating containing a filler and a mineral binder, characterized in that it contains aluminum, iron, or calcium, or magnesium hydroxide as a filler, or a mixture of any hydroxides of these metals with a particle size of not more than 100 microns, and as a mineral a binder - liquid glass or an aqueous solution of sodium polyphosphate with a density of 1300-1400 kg / m ³ in the following ratio of components, wt.%: the specified mineral binder 20-60 the specified filler 40-80.