RU2400506C1 - Heat insulation composition - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: invention discloses a heat insulation composition containing the following in wt %: alumosiliceous inorganic binder (30-77), organic binder selected from a group of aqueous dispersions of acrylate, butadiene, polyurethane, vinylacetate polymers, copolymers of acrylate with styrene, butadiene styrene copolymer, polyvinyl alcohol and their mixtures (6-50), hollow 20-200 mcm glass microspheres with packed density of 0.18-0.30 g/cm3 (12-30), auxiliary components in form of colouring pigments, ammonium polyphosphate and hydrosil (5-20) and titanium dioxide (0-3). ^ EFFECT: disclosed composition improves heat insulation properties of coatings for different surfaces in severe conditions with simultaneous protection from corrosion, improves environmental properties and simplifies the technology of preparing coatings, increases fire resistance and longevity. ^ 1 cl, 2 tbl, 5 ex

Description

The invention relates to heat-resistant coatings for surfaces of any shape that require thermal protection, used in various industries: as a heat-resistant coating (TZP) of pipelines of heating networks, boilers and other thermal apparatuses; for coating equipment to protect personnel from contact burns with hot metal surfaces (up to 260 ° C); as an anti-condensate and anti-corrosion coating for cold water pipelines, refrigeration equipment operated in rooms with adverse humidity and temperature conditions; for external thermal insulation of buildings and structures and internal processing of premises in order to prevent freezing and dampness of walls.

A known composition for producing an anti-corrosion, fire-resistant and heat-insulating coating, including epoxy resin, hardener (amines or polyamides), hollow microspheres, target additives - plasticizers, coloring pigments, etc. (RU ⁽¹¹⁾ 2301241 ⁽¹³⁾ C2, 2007). The disadvantage of this composition is the need for its manufacture immediately before use.

The patent RU ⁽¹¹⁾ 2318782 ⁽¹³⁾ C1 is known for a heat-insulating coating made of a composition comprising components in a dry form: a binder - dry redispersible liquid glass or a mixture of it with cement, hollow microspheres, fillers. The main disadvantages of the product are:

- preparation of the coating immediately before use by mixing the dry product with water at plus temperature;

- caking of the product over time and when wet.

A fireproof heat-resistant coating is known, obtained on the basis of polymer binders - phenolofurfural-formaldehyde resin, a copolymer of vinyl chloride with acrylonitrile, an epoxy diane resin, a plasticizer - phosphpolyol, a pore-forming agent - acetone, a filler - perlite, talc, mica, and a hardening agent-alcohol hexametate; ⁽¹¹⁾ 2215765 ⁽¹³⁾ C2, 2007). The disadvantage of the proposed structure are:

- the use of organic solvents - acetone, aliphatic alcohol, which worsen the environmental situation, create a fire hazard in the manufacture and use of the composition, especially when used indoors;

- the use of perlite and acetone as a blowing agent creates an open-pore system, which leads to an increase in moisture capacity during condensation of water vapor and the deterioration of heat-shielding properties.

The closest in technical essence (prototype) is a composition for obtaining an anti-corrosion, fire-resistant and heat-insulating coating, proposed in patent RU ⁽¹¹⁾ 2288927 ⁽¹³⁾ C1, 2005. The composition includes liquid sodium or potassium glass, the filler is a mixture of hollow microspheres, nonionic surface - active substance, reinforcing filler - expanded vermiculite or asbestos filaments, titanium dioxide. The disadvantage of this composition is the increased water absorption of the coating, associated with the hydrophilicity of water glass and the presence of a surfactant, the rigidity of the system, the likelihood of cracks and a decrease in the basic properties of the coating - thermal protection.

The technical task of the claimed invention is to provide heat-insulating properties of the coating of various surfaces, including metal, in particular surfaces of pipelines operating in specific, harsh conditions, while protecting them from corrosion, improving environmental properties and simplifying the technology of coating, increasing fire resistance and durability.

The stated technical problem is achieved in that the composition of the composition forming the coating on surfaces of various nature includes inorganic (30-77%) and organic (6-50%) binders, filler (12-30%) and auxiliary components (5-20 %).

As an inorganic binder, alumina-silica sol with a low content of sodium oxide (1.0-2.0 g / l) was selected. Reducing the content of sodium oxide in aluminosilicon increases the crack resistance of the coating. Alumina-silica sols are aqueous colloidal systems with nanoscale particles of a spherical shape. The particle size is from 7 to 100 nm, depending on the type of hydrosol. The use of an inorganic binder with nanoscale particles gives the heat-shielding composition enhanced properties of incombustibility, thermal protection and adhesion to surfaces.

The organic binder is selected from the group of aqueous dispersions of polymers of acrylate, butadiene, polyurethane, vinyl acetate, copolymers of acrylate with styrene, styrene-butadiene copolymer, polyvinyl alcohol and mixtures thereof.

When mixed with an organic polymer, aluminosilicon passes into a gel, resulting in the formation of a thixotropic system. The combination of nanosized particles of an inorganic binder and an organic polymer increases the strength, adhesion, elasticity, and crack resistance of the coating.

Filler - closed non-combustible glass hollow microspheres ranging in size from 20 to 200 microns, which are free-flowing powders with a bulk density of 0.18-0.30 g / cm ³ , grades MC or MS-B, MS-A, ASM-500. A mixture of glass hollow microspheres with zero water absorption provides a high degree of filling the free space of the composition and, as a result, high heat-shielding properties. The use of microspheres with zero water absorption gives the coating stability of heat-shielding properties when the coating is wetted.

Auxiliary components - coloring pigments, ammonium polyphosphate, hydrosil and titanium dioxide, which gives the composition reflective properties.

A method of obtaining a heat-shielding composition.

With constant stirring, the inorganic and organic binder is successively introduced into the mixer with small portions, then titanium dioxide, a coloring pigment, a filler and the required amount of water are successively added to obtain a certain mass density, and stirring is carried out at room temperature for 40-45 minutes until a homogeneous composition is achieved mixtures.

The finished heat-shielding composition obtained by the sol-gel technology is a homogeneous paste-like mass. The composition is easy to use, easily diluted with water and can be applied to the surface with a brush, spatula, as well as mechanically. After application to the surface and drying, a dense waterproof non-combustible heat-protective coating is formed. The thickness of the finished coating is from 1 to 3 mm, depending on the purpose.

An advantage of the heat-shielding composition is the absence of organic solvents in its composition. Environmentally friendly coating is used for exterior and interior use.

Table 1 presents specific examples claimed as the invention of the composition, and table 2 shows some of the properties of the resulting coatings.

Table 1 Name of components The content of the components according to the examples, wt.% Example 1 Example 2 Example 3 Example 4 Example 5 Aluminosilicon 25% 70 62 thirty thirty thirty Polyvinyl alcohol 10% 6 12 - - - Acrylic dispersion 48-51% - - - thirty 28 Polyurethane dispersion - - 35 10 12 Ammonium polyphosphate four 7 5 8 Microspheres 16 fourteen twenty 17 17 Hydrosil 5 5 5 5 5 Titanium dioxide 3 3 3 3 0

Table 2. Name of parameters By examples Test method Example 1 Example 2 Example 3 Example 4 Example 5 one 2 3 four 5 6 7 Water absorption in 24 hours by volume,% 0,03 - - four four TU 2316-089-00209600-2005 Contact thermal conductivity, W / m K 0.05 0,054 0,07 0.08 0.08 GOST 7076-99 The adhesion to metal, kg / cm ² 9.4 separation cohesive by TZP 7.2 cohesive separation by TZP 6.4 cohesive separation by TZP 6.4 cohesive separation by TZP 6.7 separation cohesive by TZP GOST 26589-94 Adhesion to concrete, kg / cm ² 9.8 cohesive separation by TZP 9.1 cohesive separation by TZP 8.0 cohesive separation by TZP 7.6 separation cohesive by TZP 7.9 cohesive separation by TZP GOST 26589-94 Conditional tensile strength, kgf / cm ² 12 11.3 7.9 7.1 7.3 GOST 26589-94 Elongation at break,% 14.0 14.0 15,2 14.8 15.0 GOST 26589-94 Corrosion resistance Steady Steady Steady Steady Steady GOST 9.403-80 Open flame Does not burn Does not burn Self extinguishing Self extinguishing Self extinguishing

Claims (1)

A heat-shielding composition including hollow glass microspheres, titanium dioxide, characterized in that aluminosilicon is used as an inorganic binder, hollow glass microspheres vary in size from 20 to 200 microns and bulk density in the range from 0.18 to 0.30 g / cm ³ , and the composition further comprises an organic binder selected from the group of aqueous dispersions of polymers of acrylate, butadiene, polyurethane, vinyl acetate, copolymers of acrylate with styrene, styrene-butadiene copolymer, polyvinyl water alcohol and mixtures thereof, and auxiliary components presented in the form of coloring pigments, ammonium polyphosphate and hydrosil; and titanium dioxide, the ratio of the components of the heat-shielding composition is, wt.%:
inorganic binder - aluminosilicon 30-77 organic binder 6-50 hollow glass microspheres 12-30 titanium dioxide 0-3 auxiliary components 5-20