JPH04295075A - Refractory coating composition - Google Patents

Abstract

PURPOSE:To provide the refractory coating compsn. for buildings which is improved in working environment, finish beauty and durability by compounding hydraulic cement, inorg. lightweight aggregate, endothermic material, foaming agent, soft setting agent, low-thickening property thickener, and fibers at specific ratios. CONSTITUTION:This compsn. is formed by compounding, by weight%, (a) 15 to 60 hydraulic cement, (b) 5 to 58 inorg. lightweight aggregate having 0.01 to 1.5mm grain sizes, (c) 25 to 75 endothermic material having 50 to 500 deg.C heat absorption peak, 0.05 to 10 mu average particle diameters and >=300cal/g heat adsorption quantity in pyrolysis, (d) 0.05 to 3 foaming agent which grows to >=20mm right after and to >=75% thereof after 5 minutes when the forming power is measured by a Los Miles Method at 25 deg.C, (e) 0.1 to 5 soft setting agent, (f) 1 to 10 low-thickening property thickener, and (g) 0.1 to 3 pollutionfree fibers. The curing property of this compsn. is improved by the component (a); the heat insulation and weight reduction of the coating material are improved by the component (b); the fire resistance is improved by the selection of the component (c); the weight is further reduced by the component (d); the construction characteristic is improved by the component (e); the adhesive strength to steel products is improved by the component (f), and the cracking of the coating material is prevented by the component (g).

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to fire-resistant coating compositions for buildings. Therefore, the application is in the architectural field.

0002

BACKGROUND OF THE INVENTION In recent years, there has been an increase in the number of buildings constructed using steel frames rather than reinforced concrete structures due to shorter construction periods and a shortage of craftsmen. The steel frames of this steel structure must be covered with a prescribed fireproof coating to ensure that the temperature rise in the event of a fire is within a certain limit and to prevent the building from collapsing. In Japan, asbestos spraying was practiced before 1975, but it has been banned since 1975 due to health problems caused by handling asbestos, environmental pollution due to asbestos scattering, and harm to the human body. Wool is being sprayed. Spraying rock wool is excellent in terms of economy, but recently it has become known that the working environment is poor due to the scattering of rock wool fibers.
It is avoided due to its unsightly appearance and poor surface strength.

[0003]Furthermore, there are fireproof coating materials other than those mentioned above that use water glass as a binder, but they have problems with water resistance or weather resistance and lack practicality.

[0004] To improve these, Japanese Patent Application Laid-open No. 1983
There was a combination of cement, re-emulsifiable synthetic resin emulsion powder, lightweight aggregate, and highly hydrated substances in specific proportions, as disclosed in No. 52188. However, this also had the disadvantage of being expensive and lacking in versatility.

[0005]

[Problems to be Solved by the Invention] This invention solves the problem of the poor working environment, lack of finished appearance, lack of durability, lack of efficient fire resistance performance, and poor adhesion to steel materials in the conventional fireproof coating in the construction field. This is an attempt to solve problems such as lack of economic efficiency and total lack of economic efficiency.

[0006]

[Means for Solving the Problems] The composition of the present invention generally includes 15 to 60% by weight of hydraulic cement, 5 to 58% by weight of inorganic lightweight aggregate, 25 to 75% by weight of endothermic material, and a foaming agent. 0.05-3% by weight, 0.1-5% by weight of soft coagulant, 1-10% by weight of low-viscosity thickener, 0.0% by weight of non-polluting fiber.
1 to 3, the hydraulic cement gives the composition hydraulic properties, the inorganic lightweight aggregate makes the covering material more insulating and lightweight, and the selection of endothermic substances improves fire resistance. A foaming agent is used to further reduce weight and economy, a soft setting agent improves workability, and a low-viscosity thickener increases adhesion to steel materials to prevent peeling accidents, making it non-polluting. Fibers prevent cracks in fireproof coatings,
This is a more practical fireproof covering material in total.

The composition of the present invention will be explained in detail below. First of all, hydraulic cement includes various types of Portland cement specified in JIS-R5210, white Portland cement, various types of blast furnace cement specified in JIS-R5211,
Various silica cements specified in JIS-R5212, J
Any or a combination of mixed cements such as various fly ash cements specified in IS-R5213, or mixed with calcined gypsum or alumina cement in a proportion within 20% by weight based on the total hydraulic cement. This is what I did. This hydraulic cement acts as a binder for the fireproof coating composition. The amount of such hydraulic cement used is in the range of 15 to 60% by weight. If the amount of hydraulic cement used is less than 15% by weight, the strength of the coating composition will be weakened;
If it exceeds this value, it becomes easy to crack due to thermal strain during heating. When mixing calcined gypsum and alumina cement, if the amount exceeds 20% by weight based on the total hydraulic cement, rapid setting will become strong and workability is unfavorable. It can be done quickly.

[0008] Next, inorganic lightweight aggregates include hollow foams made by heating and processing naturally or industrially produced shirasu, glass waste, nacre, obsidian, and mica-like minerals, such as shirasu balloons, glass balloons, and perlite. , fired vermiculite, anti-firestone, and natural pumice. These non-combustible inorganic lightweight aggregates can be used alone or in combination, but the particle size is 0.01~
One in the range of 1.5 mm is good. Particles with a particle size of less than 10μ are undesirable because they scatter more during kneading;
Anything exceeding this is not preferable for constructing a dense heat insulating layer. Further, the apparent specific gravity is preferably in the range of 0.05 to 1.0. The amount of this inorganic lightweight aggregate used is in the range of 5 to 58% by weight. When the amount of inorganic lightweight aggregate used is less than 5% by weight, the material is not lightweight and is not preferred as a fireproof coating, and when it exceeds 58% by weight, the fireproof performance is insufficient.

Next, the endothermic substance referred to in the present invention refers to an endothermic substance whose endothermic peak in a differential thermal curve in differential thermal analysis is between 50°C and 50°C.
00°C, and the amount of heat absorbed during thermal decomposition is 300 cal/g or more in terms of standard conditions. Examples include aluminum fluoride, aluminum hydroxide, dicalcium phosphate, calcium oxalate, cobalt hydroxide,
Examples include borax, magnesium hydroxide, sodium bicarbonate, and cobalt chloride ammonia complex. Moreover, the average particle size of this endothermic substance is specified to be in the range of 0.05 to 10 μm. By using this specified endothermic material, the substantial fireproof coating performance becomes more effective than the conventionally used aluminum hydroxide with a particle size of 15 to 300 microns or calcium carbonate with a decomposition temperature of 850 DEG C. Here, the endothermic peak of the endothermic substance is limited to a range of 50°C to 500°C because fire resistance tests for steel columns and beams require the average temperature of the steel to be 350°C or less. This is because the larger the temperature difference from the combustion temperature of about 1,000°C during a fire, the greater the rate of decomposition. In this invention, the thickness is 20 mm or less and has a fire resistance of 1 hour and a thickness of 30 mm.
We sought an effective endothermic material with the aim of achieving fire resistance for 2 hours at a thickness of 0.1 mm or less, and for 3 hours at a thickness of 40 mm or less. This will be explained with reference to FIGS. 1 to 3. FIG. 1 is a diagram showing the temperature gradient between the maximum temperature inside the furnace in a 1-hour refractory heating test and the temperature of the steel material at which the refractory test passes, and similarly, FIG. is a diagram showing the temperature gradient in the case of a 3-hour fire resistance test. α indicates the rate at which a substance that absorbs heat by thermal decomposition at 500° C. can contribute to heat absorption in the fireproof coating layer. α is determined by the following formula 1, where x is the thickness of the fireproof coating layer and y is the thickness from the steel surface at a point where the temperature is 500°C.

0010

[Formula 1]

[0011] When a coating thickness of 20 mm as shown in Fig. 1 is used to provide fire resistance for one hour, endothermic substances that decompose at temperatures below 500°C have the possibility of being decomposed with a high efficiency of decomposition efficiency α = 75% or more. . When the coating thickness of 30 mm shown in FIG. 2 is used to provide fire resistance for 2 hours, an endothermic substance that decomposes at 500° C. or lower has the possibility of being decomposed with a high decomposition efficiency α of 77% or more. When the coating thickness of 40 mm shown in FIG. 3 is used to provide fire resistance for 3 hours, an endothermic substance that decomposes at 500° C. or lower has the possibility of being decomposed with a high efficiency of decomposition efficiency α=79% or more. It is thought that what is decomposed here contributes to heat absorption and can suppress the temperature rise of the steel material. Moreover, those having a thermal decomposition temperature of less than 50° C. are unstable in practical use and cannot be used. Furthermore, if the temperature exceeds 500°C, the proportion that can contribute to thermal decomposition becomes low, which is not preferable. Furthermore, the particle size is 0.05
By selecting a small value of ~10μ, the efficiency of thermal decomposition can be made more complete. When the particle size exceeds 10μ, the efficiency of thermal decomposition decreases. In addition, if the heat absorption amount per unit mass of the endothermic substance is 300 cal/g or more, the ability to suppress the temperature rise of the steel material or coating material is large, and the substantial fireproof coating performance is synergistically enhanced. Here, the amount of heat absorbed by the endothermic substance is 300
If it is less than cal/g, the performance will be insufficient. Further, the endothermic substance is effective when used in an amount of 25 to 75% by weight. The amount of this endothermic substance used is 25
If it is less than % by weight, the fire resistance will deteriorate and the coating will have to be thicker. On the other hand, if the amount is more than 75% by weight, cracking during heating becomes large, which is not preferable.

Furthermore, the foaming agent used in the present invention has a foaming power of 20 m
It is any one or a mixture of nonionic, nonionic/anionic, anionic, and zwitterionic activators that are 75% or more of the value immediately after m or more and after 5 minutes. HLB (Hydrophile-Lip) is a nonionic foaming agent.
polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, with an ophile Balance of 9 to 20. , polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene oleate ester, polyoxyethylene sorbitan monolaurate, polyoxyethylene lanolin alcohol ether, polyoxyethylene lanolin fatty acid ester, alkyl alkylolamide, lauric acid diethanolamide These include coconut oil fatty acid mono(or di)ethanolamide, oleic acid diethanolamide, lauric acid isopropanolamide, stearic acid monoethanolamide, and polyoxyethylene coconut oil fatty acid amide.

[0013] As a nonionic/anionic foaming agent, polyoxyethylene alkyl (or alkylaryl)
There are phosphoric acid esters of ethers. Anionic foaming agents include sodium polyoxyethylene lauryl sulfate, triethanolamine polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, triethanolamine polyoxyethylene alkyl ether sulfate, sodium alkyl sulfate, and alkyl ether. Sodium sulfate, sodium lauryl ether sulfate, triethanolamine alkyl sulfate, fatty acid soda (potash) soap, castor oil potash soap, sodium lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl sulfate, sodium 2-ethylhexyl alkyl sulfate, normal dodecyl Examples include sodium benzene sulfate, sodium acyl methyl taurate, sodium lauroyl methyl taurate, sodium dialkyl sulfosuccinate, sodium dovanol ethoxy sulfate, and sodium N-coconut oil fatty acid acyl-L glutamate. Examples of zwitterionic foaming agents include 2-undecyl N-carboxymethyl N-hydroxyethylimidazolinium betaine, 2-alkyl N-carboxymethyl N-hydroxyethylimidazolinium betaine, lauryl carboxymethyl hydroxyethylimidazolinium betaine, lauryl aminopropio There are such things as Nate.

[0014] The amount used is in the range of 0.05 to 3% by weight, but especially in order to obtain long-term stability of the foam, foam stability can be determined by measuring the foaming power using the Ross Miles method. It is desirable to use a foaming agent whose foaming power value after 5 minutes is 75% or more of the value immediately after, and to have a concentration of about 0.2 to 3% by weight.

Furthermore, the fireproof coating composition of the present invention comprises 1 to
Silicic acid represented by the general formula M2O.nSiO2 (where M is an alkali metal and n is a number from 1.5 to 7.0) is used as a soft coagulant to enable recoating in a relatively short time of 4 hours. Contains or uses salt compounds, colloidal silica, or a mixture thereof. The effect is obtained when the content or amount used is 0.1 to 5% by weight. If the amount used is less than 0.1% by weight, the coagulation effect will be small and the time between coatings cannot be shortened. Moreover, if it exceeds 5% by weight, the coagulation effect is too large and it becomes difficult to pump.

[0016] The low-viscosity thickener is methylcellulose, whose viscosity in a 2% aqueous solution is 1,000 cps or less at 30 rpm using a BM viscometer when measured at a solution temperature of 20°C. Either or a combination of synthetic polymer thickeners such as polyvinyl alcohol and hydroxyethyl cellulose, or natural polymer thickeners such as guar gum and alginic acid derivatives, and the amount used is 1.
It is effective when the amount is 10% by weight. In particular, low-viscosity thickeners are used here because, compared to high-viscosity thickeners, they do not become extremely viscous even when used in a large proportion, and there is no problem in using them. This is because the foam stabilizing effect can be enhanced and the adhesion strength can be strengthened at the same time.

Furthermore, the pollution-free fiber is a fiber selected from carbon fiber, vinylon fiber, alkali-resistant glass fiber, etc., with a fiber length of 2 to 20 mm and a fiber diameter of 1 μ to 300 μ.
It works to reduce cracking caused by deformation such as shrinkage of fireproof coating materials at room temperature or at high temperatures. Here, the harmfulness of fibers is said to be mainly due to the fiber diameter and shape, and in particular, fibers that are extremely thin with a fiber diameter of 0.1 to 0.01 μm, such as conventionally used asbestos, are carcinogenic. Therefore, in this invention, the fibers, fiber length, and fiber diameter are selected to ensure that they are not harmful. Moreover, its usage ratio is 0.1 to 3% by weight, which is effective.

[0018] In addition, kaolin, clay, calcium carbonate, china clay, diatomaceous earth, talc, bentonite,
Extender pigments such as barium sulfate and alumina, titanium oxide,
Various coloring pigments such as red iron, orca, carbon black, phthalocyanine blue, and phthalocyanine green, as well as rust preventives and dust preventive agents, may be added as necessary. These auxiliary additions are used in place of hydraulic cement and inorganic lightweight aggregate to the extent that they do not impair the purpose of the present application, up to a total of about 30% by weight.

The composition of the present invention is kneaded and stirred with an appropriate amount of water to form a paste containing microbubbles of a predetermined volume, which is then used by being pumped and sprayed onto an object to be coated using a spray gun.

In the present invention, when using the above composition, a fire-resistant coating layer can be obtained more reliably by using the following usage method. That is, the total volume when a unit amount of the composition of the present invention is made into a paste is 10 to 200% larger than the total volume when the paste is completely defoamed, and the average diameter of the bubbles is 1 mm or less. The specific gravity of the composition after solidification is 0.2 to 1.0 at air-dry equilibrium. In order to obtain the desired foaming ratio, the type or concentration of the foaming agent is changed. In addition, to obtain microbubbles, when using stirring, increase the circumferential speed during stirring, and use the column method (a method in which a foaming agent solution or foaming agent-containing slurry is passed through a column and air to form foam).
In this case, the gap between the columns should be made smaller.

[0021]

[Function] The fireproof coating composition of the present invention maintains the strength of the fireproof coating material by keeping the proportion of hydraulic cement within a certain range, and has less shrinkage cracking even when heated, and is made of inorganic lightweight bone with fine particle size. After specifying the endothermic peak and amount of heat absorption of the endothermic substance, the temperature range in which the endothermic reaction occurs can be determined for the performance of the fireproof coating by selecting the particle size. be efficient,
It makes the effect per unit mass effective, and the action of the foaming agent makes the fireproof coating material porous and has excellent heat insulation properties. Furthermore, by setting the capacity increase due to foaming to a range of 10 to 200%, it is possible to achieve an economical product with excellent spraying workability and fireproof coating performance. In addition, a soft setting agent shortens the time between coats to improve workability, a low-viscosity thickener increases adhesion to steel and prevents peeling accidents, and non-polluting fibers improve fireproof coating. prevents cracking.

[0022]

[Examples] The present invention will be explained below with reference to Examples. The formulations of Example 1 to Example 12 and Comparative Examples 1 to 6 are shown in Tables 1 and 2 below, and their performances are shown in Table 3. In the table, the numerical values indicating percentages are weight %. Component A1 is Portland cement, A2 is alumina cement, B1
Shirasu balloon is an inorganic lightweight aggregate (bulk specific gravity is 0.
20) with a particle size of 10-250μ, B2 is pearlite (bulk specific gravity 0.40) with a particle size of 0.1-1.2mm.
B3 is natural pumice (bulk specific gravity 0.80) with a particle size of 60 to 250μ, B4 is Shirasu balloon (bulk specific gravity 0.20) with particle size 1.6 to 3.3 mm, B
5 is calcined vermiculite (bulk specific gravity 0.08) with a particle size of 1.6
mm to 3.3 mm, C1 is aluminum hydroxide, which is an endothermic substance, with an average particle size of 1 μm, C2 is aluminum hydroxide, with an average particle size of 100 μm, and C3 is calcium carbonate, with an average particle size of 1 μm. D1 is polyoxyethylene lauryl ether with an HLB of 10 as a foaming agent (95mm immediately after and 75mm after 5 minutes in foaming power measurement under specified conditions), D2 is a foaming agent with a diameter of 25μ D3 is laurylcarboxymethylhydroxyethylimidazolinium betaine as a foaming agent (190 mm immediately after foaming power measurement under specified conditions, 160 mm after 5 minutes) as a foaming agent (under specified conditions The foaming force measurement was 170 mm immediately after, 145 mm after 5 minutes, and D4 was HL
B is polyoxyethylene nonylphenyl ether, a surfactant with an HLB of 8 (160 mm immediately after and 135 mm after 5 minutes in the foaming force measurement under the specified conditions), and D5 is sorbitan monolaurate, a surfactant with an HLB of 8 ( In the foaming force measurement under the specified conditions, 15 mm immediately after and 1 mm after 5 minutes.
0mm), E1 is MIZUKANEX-100 (manufactured by Mizusawa Chemical Industry Co., Ltd.), a special water glass represented by the general formula M2O・nSiO2, and F1 is HEC-UNICEL QP-09L, a low-viscosity thickener made of hydroxyethyl cellulose. (
The viscosity of a 2% aqueous solution is 10 cps (manufactured by Daicel Chemical Industries, Ltd.), and G1 is chopped strand carbon fiber.
Further, as auxiliary additives, H1 indicates alumina as an extender pigment, and H2 indicates titanium oxide as a coloring pigment.

[0023]

[Table 1]

[0024]

[Table 2]

Approximately 80 parts by weight of water was added to 100 parts by weight of the composition prepared as described above and stirred to obtain a slurry of the fireproof coating composition containing foam. In addition, the rate of increase in capacity due to foaming at that time was investigated. Then, in order to use it for various tests, it was sprayed onto steel materials, iron plates, etc. at a thickness of 20 mm (the thermal conductivity test specimen was a molded body with a thickness of 50 mm), and was heated in a constant temperature room at 20°C and 60%. After being cured for a month and further brought to a constant weight at 50°C, it was subjected to each test.

[0026]

[Test items and test methods] ■Foaming ratio composition 100
When the weight part is made into a foamy slurry with an appropriate amount of water, the volume is a
and the capacity when it is completely degassed under vacuum is b,
The capacity increase rate c (%) due to foaming is calculated using the following formula.

[0027]

[Formula 2]

② Bulk Specific Gravity After the molded body has a constant weight, the weight/capacity is calculated. ■Thermal conductivity test Using a thermal conductivity meter TC-32 manufactured by Kyoto Electronics Industry Co., Ltd.
Measured by hot wire method. ■Fire resistance performance test Each foam slurry composition was sprayed to a specified thickness on a steel material with a thermocouple attached to the center, and the specimen was cured for a specified period to achieve a constant weight and heated along the JIS-A-1304 standard heating curve. The time required for the temperature to reach 350°C is measured and evaluated by dividing the temperature by the specific gravity of each test piece. ○, 1 if the result is 140 or more
40 to 100 is Δ, and less than 100 is ×. ■ Adhesive strength test A 7 cm square specimen that has been sprayed onto an iron plate and cured in a prescribed manner is used to conduct an adhesive strength test under standard conditions specified in JIS-A-6909. ■ Spraying property test Under constant conditions of room temperature 20℃ and humidity 60%, materials of each composition with appropriate spray viscosity are first sprayed to a thickness of about 10 mm on a vertical iron plate at a constant interval of time. The quality is judged by whether the second layer is layered and it slides down. Those that do not fall off are marked as ○, those that shift slightly are marked as △, and those that shift significantly are marked as ×.

[0029]

[Table 3] In Table 3, symbol *1 is kcaI/m・hr・℃, *2 is g/
Let it be cm2.

[0030]

According to the present invention, the poor working environment caused by scattering of fibers, which is a disadvantage of sprayed rock wool, can be improved. Moreover, by making microbubbles easy to generate and stabilizing them, the weight of the coating layer can be reduced, and an economically effective fireproof coating layer can be obtained. Furthermore, by using microscopic lightweight aggregates, it is possible to improve heat insulation and lightweight properties. By using a specific endothermic substance as referred to in the present invention, effective fire resistance can be ensured. In addition, the soft setting agent can shorten the time between coats and improve workability. In addition, the low-viscosity thickener increases the adhesion to steel materials and prevents peeling accidents. In addition, non-polluting fibers can reduce cracking. In addition, when white Portland cement is used as the hydraulic cement, cosmetic properties can be obtained by adding colored pigments.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the decomposition efficiency of an endothermic substance using a temperature gradient line in a refractory coating layer at the maximum temperature in the furnace in a 1-hour fire resistance test.

FIG. 2 is a diagram illustrating the decomposition efficiency of an endothermic substance using a temperature gradient line in the refractory coating layer at the maximum temperature in the furnace in a 2-hour fire resistance test.

FIG. 3 is a diagram illustrating the decomposition efficiency of an endothermic substance using a temperature gradient line in the refractory coating layer at the maximum temperature in the furnace in a 3-hour fire resistance test.

Claims (1)

[Claims] Claim 1: When the entire composition is 100% by weight, 15 to 60% by weight of hydraulic cement as a binder.
5 to 5 ~ ■ inorganic lightweight aggregates with particle sizes ranging from 0.01 to 1.5 mm selected from among , whitebait balloons, fired hill stones, glass balloons, perlite, anti-fire stones, natural pumice, etc.
58% by weight, the endothermic peak of the differential thermal curve in differential thermal analysis is in the range of 50°C to 500°C, the endothermic amount in thermal decomposition is 300 cal/8 or more, and the average particle size is 0.
25 to 75% by weight of an endothermic substance in the range of 05 to 10μ, and the foaming power was measured by the Ross Miles method at 25°C under the conditions of using a 0.1% foaming agent aqueous solution (
(hereinafter simply referred to as measurement of foaming power under specified conditions),
20 mm or more immediately after and 75% or more of the value immediately after 5 minutes ■ 0.05 to 3% by weight of a foaming agent, and M2
O・nSiO2 (M is an alkali metal, n is 1.5
0.1 to 5% by weight of a soft coagulant of either silicate or colloidal silica or a combination thereof, and the viscosity of a 2% aqueous solution (at 20°C) is the viscosity value of BM type viscometer at 30 rpm, which is 1,00.
Synthetic polymer thickeners such as methyl cellulose, polyvinyl alcohol, and hydroxyethyl cellulose, or natural polymer thickeners such as guar gum and alginic acid derivatives, or a combination of these, resulting in 0 cps or less ■
1 to 10% by weight of a low-viscosity thickener, and further 0.0% pollution-free fiber with a fiber length of 2 to 20 mm and a fiber diameter of 1 to 300 μm selected from alkali-resistant glass fibers, carbon fibers, vinylon fibers, etc. A fire-resistant coating composition comprising 1 to 3% by weight of the above (1) to (3).