KR100530670B1 - Refractory Paint Film Composition - Google Patents

Abstract

The present invention relates to an inorganic refractory coating film composition having excellent heat resistance under expansion and expansion at high temperature, and includes 5 to 89% by weight of silicate, 5 to 50% by weight of silica, 5 to 70% by weight of functional filler, and 0.5 to 10% by weight of thickener. , 0.3-10% by weight of reinforcing agent and 0.2-5% by weight of additive, and when the silicate used as the binder receives heat in case of fire, the crystal water inside the silicate is expanded and the expanded cell is destroyed. It is excellent in fireproof insulation effect even at high temperature by forming a heat insulation layer up to high temperature by newly expanding inside the cell in which expandable graphite is destroyed.

Description

Refractory Paint Film Composition

The present invention relates to a fireproof coating film composition, and more particularly, to a silicate or modified silicate using various types of silica to increase the molar ratio of the silicate as a binder, and to use a functional filler, a thickener, an additive and a solvent. The present invention relates to an inorganic coating composition which forms a thermal insulation layer having excellent heat resistance under expansion of foaming and high temperature.

In general, the coating composition for the refractory coating is mainly composed of a composition using an organic resin and ammonium polyphosphate. Refractory coating compositions of the type using such organic materials are abundant outflow of ammonia gas, toxic gas when foaming, and there is a limit to the thermal insulation effect is limited use area and use.

Korean Patent Publication No. 91-6378 discloses a technique for inorganic coating compositions using silicate or modified silicate as a subject and using a phosphoric acid compound as a curing agent.

Such paints are excellent in heat resistance and can form a strong inorganic coating, but they are not suitable for use in foamed refractory paints because they inhibit foam expansion and expansion due to the influence of the phosphoric acid compound used.

In addition, Korean Patent Publication No. 89-10138 discloses a technique for foaming refractory inorganic fire retardant using a liquid metal silicate as a main binder. In the case of such a composition, foam insulation is very excellent, but the heat resistance of the metal silicate used is In the high temperature of about 600 ° C. or more, the foam coating layer softens and flows down.

Japanese Unexamined Patent Publication No. 5-86310 discloses a coating composition for a foamable refractory paint using ammonium polyphosphate as a blowing agent, melamine as a carbon generating material, and a modified epoxy as a binder.

This type of paint is a type of paint that protects the body from heat by allowing the paint composition to receive heat and chemically react at around 400 ° C. to form a carbon layer to form a thick thermal insulation layer. As well as releasing a large amount of ammonia gas, the foam layer itself is formed of a very weak carbonized layer has the drawback that the foam layer is easily broken by hot air in the event of fire.

It is an object of the present invention to provide a fireproof coating composition which is excellent in coating film strength and heat resistance of the foam layer and is free of harmful gases such as ammonia gas as an inorganic type.

In order to achieve the above object, the fireproof coating composition of the present invention includes 5 to 89% by weight of silicate or modified silicate, 5 to 50% by weight of silica, 5 to 70% by weight of functional filler, 0.5 to 10% by weight of thickener, and 0.3 to 1% of reinforcing agent. It is characterized by consisting of 10% by weight and 0.2 to 5% by weight of the additive.

The present invention will be described in more detail as follows.

The present invention is made of silicate or modified silicate compound using various types of silica as a main binder, and a refractory coating film composition formed by adding a functional filler, a pigment, a thickener, a solvent and other additives that cause an endothermic reaction at a high temperature. It is about.

The foaming / expansion adiabatic mechanism of the inorganic refractory coating film composition is as follows; The silicate coating film used as a binder has 30-60% of crystal water, and these crystal waters form various types of cells with foam expansion inside the film when they are subjected to a temperature of 180 ° C. or higher to exhibit an insulating effect. These cells are melted at a temperature of 600 ° C. or higher to become viscous and thus cannot be used for the purpose required by the present invention. Accordingly, the present invention maintains these cells even at a high temperature (about 1000 ° C.) to provide an inorganic refractory coating film composition having excellent fire insulating effect.

The silicate used in the present invention is a compound represented by M ₂ O.nSiO ₂ .xH ₂ O, where M represents a metal belonging to group 1A of the periodic table, n is an integer from 2 to 6, and x is from 20 to 40. Is an integer.

Specific examples of the metal include lithium, sodium and potassium.

The silicate is selected in consideration of the properties and physical properties of the composition, and is selected in consideration of water resistance, heat resistance, foaming rate, adhesion to the body. In the present invention, one of the above-mentioned silicates is selected as the silicate or the modified silicate, and one or two or more thereof are mixed and used.

The content of the silicate binder is preferably 5 to 89% by weight in the total coating composition.

This type of silicate is excellent in foaming capacity per se, but it is impossible for the foamed layer to maintain heat resistance of at least 1000 ° C. while maintaining a density even under high temperature. In order to solve this problem, in the present invention, by increasing the molar ratio of silicate using various types of silica in the silicate, not only the heat resistance of the silicate can be increased, but also excellent heat resistance can be maintained without degrading the density of the silicate foam layer at a high temperature.

Generally, fumed silica, colloidal silica, and micronized silica can be used as the type of silica to be added. It can dissolve by itself and increase the molar ratio of silicate. Increasing the molar ratio of silicate using this method increases the heat resistance of the silicate, but the storage stability becomes unstable. The content of such silica is 5 to 50% by weight of the total coating composition, wherein the molar ratio of silicate is 2.9 to 7. If the content of silica is less than 5% by weight, the heat resistance of the foamed coating film is lowered. If the content of silica is more than 50% by weight, cracks are generated in the dry coating film and the storage life of the silicate is shortened, so that the content is preferably 10 to 30% by weight.

The coating composition of the present invention contains a functional filler in order to increase the dry strength of the foam layer and to exhibit a more effective function in a fire, and the functional filler remains in the foam coating film and undergoes an endothermic reaction according to a temperature rise. It plays a role in preventing temperature rise. As a specific compound of a functional filler, expandable graphite is an essential component, and it can select and mix among magnesium calcium carbonate, calcium carbonate, and aluminum hydroxide here. When the silicate used as the binder receives heat in the event of fire, the crystal water inside the silicate is expanded and the expanded cell is destroyed. At this time, the expanded graphite is newly expanded inside the cell where the expandable graphite is destroyed to form an insulating layer up to a high temperature.

The content of these functional fillers is 5 to 70% by weight of the total coating composition, and if the content is less than 5% by weight, the effect of adding the functional filler is insignificant, and if the content is more than 70% by weight, the density of the foam layer of the alkali metal silicate decreases. On the contrary, the fireproof insulation effect is lowered. In view of this, the content of more preferable functional filler is 20 to 35 weight%.

In addition, in the present invention, in order to facilitate the spray workability and workability of the paint, one or two or more kinds of cellulose compounds (methylcellulose, ethyl cellulose), aluminum silicate, aluminum magnesium calcium silicate, etc. are used as a thickener. Bars, such thickeners serve to increase the thixotropy, that is, the TI value of the composition when preparing the composition. The content of such additives is 0.5 to 10% by weight based on the entire coating composition. If the content of the additive is less than 0.5% by weight, the use effect is lowered, if it is more than 10% by weight there is a fear of adverse effects due to excessive viscosity rise. Preferably it is 1-3 weight%.

On the other hand, cracks may occur due to dry shrinkage of the coating after forming the coating. In order to prevent such drying shrinkage, reinforcing agents such as ceramic fibers, glass fibers, or Ti-based whiskers are added to prepare the coating composition.

These reinforcing agents are in the form of fibrous particles and remain in the dry coating film of the above-described coating compositions to serve as a reinforcing material in the coating film during dry shrinkage by outside air.

The content of such reinforcing agents is 0.3 to 10% by weight of the total composition. If the content of the reinforcing agent is less than 0.3% by weight, cracks may occur in the dry coating film. If the content of the reinforcing agent is more than 10% by weight, the spreadability of the coating film is bad and there is a difficulty in preparing the composition. Preferably it is 0.7-3 weight%.

In addition, in the present invention, surfactants and other additives such as sodium hexasulfonate, ammonium acrylate copolymer, polycarboxylic acid alkylol ammonium salt, polysiloxane emulsion, or the like are used alone or in combination of two or more thereof. Dropping facilitates workability during composition preparation and construction. It is preferable that the content of these additives is 0.2 to 5% by weight, and if the content is less than 0.2% by weight, it is impossible to obtain an effect corresponding to the purpose of use, and when it is more than 5% by weight, paints may have defects such as craters. .

When the viscosity is appropriately adjusted by using water as a solvent in the composition as described above, it is possible to complete the film composition according to the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Examples 1-5 and Comparative Examples 1-3

Water is added to the alkali metal silicate resin as a solvent and other additives are added, followed by dissolving the functional fillers and reinforcing agents in order, and then re-dispersed using a pre-mixing or ball mill at a speed of 200 rpm or more for 20 to 30 minutes. A film composition of was prepared.

The composition and content are as shown in Table 1 below.

Furtherance compound Example Comparative example One 2 3 4 5 One 2 3 bookbinder Sodium silicate 30 30 30 40 35 50 70 65 Potassium silicate 10 - 5 - - 30 - - Lithium silicate - 10 5 - 3.5 20 - - Silica Colloidal silica 15 - - 10 15 - - - Fumed silica - 15 - 10 15 - 21 8 Micronized silica - - 15 - - - - - Functional filler Magnesium Calcium Carbonate 10 - 10 5 4 - - - Calcium carbonate - 10 - 5 4 - - - Magnesite - - 10 - - - - - Expandable graphite 3 4 2 5 10 - - - Reinforcement Ceramic fiber 1.0 - - 0.5 1.0 7 - - glass fiber - 1.0 - 0.5 - - - - Ti whiskers - - 1.0 - - - One - Thickener Silica, Alumina, Magnesium Hydroxide 5 5 6 4 3.0 - - - Methyl cellulose One - - 0.5 1.5 5 - - Ethyl cellulose - One - 0.5 - - - - Other additives Sodium hexasulfonate 0.2 0.2 0.2 0.1 0.5 - - - Ammonium acrylate copolymer 0.2 - - - 0.5 - - - Polycarboxylic Alkynol Ammonium Salts - 0.2 - 0.2 - - - - Polysiloxane emulsion - - 0.2 - 0.2 - - - solvent water 24.6 23.6 15.6 18.7 6.8 - - - Sum 100 100 100 100.0 100.0

The coating compositions prepared according to Examples 1 to 5 and Comparative Examples 1 to 3 were applied to H (beam: 400 × 200 × 8 × 13, pillar: 300 × 300 × 10 × 15) type steel using a vacuum coating machine. After coating in mm thickness, the temperature of the H-type steel was measured after the temperature was increased according to the KSF 2257 temperature rising schedule using a gas furnace.

The results are shown in Table 2 below.

Specimen temperature (℃) according to heating time 10 minutes 20 minutes 30 minutes 40 minutes 50 minutes 60 minutes Example One 94 (605) 100 (704) 110 (748) 153 (798) 226 (836) 318 (900) 2 93 (576) 99 (693) 102 (743) 125 (790) 191 (830) 272 (901) 3 96 (609) 101 (696) 115 (701) 158 (792) 227 (871) 339 (930) 4 95 (562) 101 (672) 101 (763) 116 (883) 175 (842) 256 (910) 5 99 (572) 101 (686) 139 (753) 194 (879) 274 (861) 386 (926) Comparative example One 95 (607) 101 (685) 123 (747) 199 (795) Film dropout Film dropout 2 97 (610) 103 (683) 140 (733) 201 (801) Film dropout Film dropout 3 99 (580) 105 (701) 139 (743) 195 (800) Film dropout Film dropout Note: () indicates the atmosphere temperature in the furnace.

From the results of Table 2, it can be seen that the coating film dropout does not occur at a high temperature as in the case of the comparative example when the coating composition to which the expandable graphite according to the present invention is added is excellent in heat resistance.

As described in detail above, the inorganic refractory coating film composition formed by adding silica to the silicate or modified silicate compound in accordance with the present invention by improving the molar ratio of the silicate in various forms and adding the expandable graphite as a functional filler is heat resistant. It is excellent in coating strength and is suitable for painting steel frame, beam and column for building.

Claims (5)

Fireproof coating film consisting of 5 to 89% by weight of silicate or modified silicate, 5 to 50% by weight of silica, 5 to 70% by weight of functional filler, 0.5 to 10% by weight of thickener, 0.3 to 10% by weight of reinforcing agent and 0.2 to 5% by weight of additive Composition. The fireproof coating composition according to claim 1, wherein the silica is selected from colloidal silica, fumed silica and micronitized silica. 2. The fireproof coating composition according to claim 1, wherein the functional filler is expanded graphite alone or a mixture with one selected from calcium carbonate, magnesium calcium carbonate, magnesite and aluminum hydroxide. The fireproof coating composition according to claim 1, wherein the thickener is selected from magnesium calcium aluminate silicate, aluminum silicate, methyl cellulose and ethyl cellulose. The fire retardant coating composition according to claim 1, wherein the reinforcing agent is one or a mixture selected from ceramic fibers, glass fibers and Ti-based whiskers.