Refractory coating repair material

Abstract

To provide a water-kneading repair material for a sprayed rock wool fireproof coating material, wherein the water-kneading fireproof coating repair material has excellent adhesion and workability, and also excellent fireproof coating property.SOLUTION: A water-kneading fireproof coating repair material includes 55-65 pts.mass of rock wool, 35-45 pts.mass of cement, 0.2-2.2 pts.mass of an anionic surfactant, and 0.1-3 pts.mass of a thickener.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a refractory coating repair material.

Background Art

[0002] Currently, refractory coating methods for construction applications are roughly classified into spraying methods, winding methods, formed plate methods, painting methods, etc. Among them, spray rock wool, which is a typical spraying method, occupies 70-80% of the market share. This is because it can cope with complex structures, continuous construction over a wide range is possible by hose pumping and the construction efficiency is high, and the cost is low. On the other hand, various works are carried out after the refractory coating work, and the spray rock wool may be damaged due to these works or contacts. In that case, it is desirable to repair it again by spraying, but there are places where spraying is no longer possible, or after completion of construction, repair by spraying may not be possible, and in many cases, the defective part is often coated with a kneaded repair material or the like.

[0003] Partial repair of spray rock wool had no choice but to be repaired again by spraying or by a kneaded repair material. In the latter case, since repair was carried out by troweling, it was necessary to add a lot of auxiliaries such as fillers and thickeners in order to improve the workability of troweling (Patent Document 1). Therefore, it is a material completely different from spray rock wool, and there were cases where it was judged not to be suitable for the fire-resistant structure certification that is recognized for each member. Therefore, the advisability of its use has been judged in terms of operation. In addition, conventional kneaded repair materials have a larger bulk density and a greater weight than spray rock wool. Therefore, when the repair material was applied to relatively fragile spray rock wool, problems such as the repair material falling off due to its weight sometimes occurred.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] An object of the present invention is to provide a kneaded repair material for a sprayed rock wool refractory coating material, which has excellent adhesiveness and workability, and also has excellent fire resistance and compatibility with the sprayed rock wool coated refractory structure.

MEANS FOR SOLVING THE PROBLEMS

[0006] Therefore, as a result of various studies to solve the above problems, the present inventor has found that by adding water to a composition containing 55 to 65 parts by mass of rock wool, 35 to 45 parts by mass of cement, 0.2 to 2.2 parts by mass of an anionic surfactant, and 0.1 to 3 parts by mass of a thickener and kneading, it has excellent troweling workability and adhesiveness to rock wool, and can maintain high fire resistance of the coating material after repair, and thus completed the present invention.

[0007] That is, the present invention provides the following inventions [1] to [4]. [1] A kneaded refractory coating repair material containing 55 to 65 parts by mass of rock wool, 35 to 45 parts by mass of cement, 0.2 to 2.2 parts by mass of an anionic surfactant, and 0.1 to 3 parts by mass of a thickener. [2] The kneaded refractory coating repair material according to [1], wherein the anionic surfactant is one or more selected from sulfonates, alkyl sulfates, alkyl ether sulfates, higher fatty acid salts, ether carboxylates, and acyl amino acid salts. [3] The kneaded refractory coating repair material according to [1] or [2], wherein the thickener is one or more selected from carrageenan, dextrin, water-soluble cellulose derivatives, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, carboxyvinyl polymer, (acrylic acid / acrylic acid alkyl (C10-30)) copolymer, xanthan gum, carboxymethyl chitin, chitosan, and polyethylene oxide. [4] The plastic refractory coating repair material according to any one of [1] to [3], which is a repair material for sprayed rock wool refractory coating.

Advantages of the Invention

[0008] The plastic refractory coating repair material of the present invention ensures a bulk density and a low thermal conductivity equivalent to those of sprayed rock wool, which could not be achieved by conventional plastic refractory coating repair materials. Furthermore, it can ensure an adhesiveness higher than the base material strength of the sprayed rock wool with respect to the sprayed rock wool. In addition, the plastic coating repair material of the present invention has good troweling workability due to the combination of an anionic surfactant and a thickener.

Embodiments for Carrying Out the Invention

[0009] The plastic refractory coating repair material of the present invention is characterized by containing 55 to 65 parts by mass of rock wool, 35 to 45 parts by mass of cement, 0.1 to 2.2 parts by mass of an anionic surfactant, and 0.1 to 3 parts by mass of a thickener. Here, the content of each component of the refractory coating repair material of the present invention is based on a total of 100 parts by mass of rock wool and cement, and the other components are in proportion to this.

[0010] Rock wool is a man-made mineral fiber produced by mixing lime etc. with basalt, steel slag, etc. and melting them at a high temperature, and its main components are silicic acid (SiO2) and calcium oxide (CaO). As the rock wool, commercially available rock wool or crushed rock wool can be used. Rock wool usually has a single fiber diameter of 3 μm to 10 μm and an average fiber length of 100 μm to 15,000 μm. The quality of rock wool is defined in JIS A 9504 "Man-made Mineral Fiber Thermal Insulation Material" and is managed according to this standard. Crushed rock wool is obtained by physically crushing rock wool, and has a single fiber diameter of 3 μm to 10 μm, the same as that of rock wool, and an average fiber length of 20 μm to 1,000 μm.

[0011] Rock wool is contained in the repair material of the present invention in an amount of 55 to 65 parts by mass. When the content of rock wool is less than 55 parts by mass, the fluidity becomes high, so the thickness that can be applied at one time becomes thin, and the workability deteriorates. On the other hand, when the content of rock wool exceeds 65 parts by mass, it is difficult to flatten the surface of the refractory coating repair material during troweling, and the trowel spread and the adhesion of the refractory coating repair material at the joint are inferior. The preferred content of rock wool is 56 to 65 parts by mass, and more preferably 57 to 64 parts by mass.

[0012] Examples of the cement used in the repair material of the present invention include Portland cements such as ordinary, early-strength, ultra-early-strength, medium-heat, and low-heat Portland cements, white cement, blast furnace cement, alumina cement, super rapid hardening cement, or eco-cement using waste materials such as municipal waste incineration ash and sewage sludge incineration ash as raw materials. One or more of these can be used. Since high initial strength can be obtained, it is preferable to use one or more selected from ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, or eco-cement.

[0013] Cement is contained in the repair material of the present invention in an amount of 35 to 45 parts by mass. When the content of cement is less than 35 parts by mass, the stickiness is low and slipping occurs with respect to the steel frame base, which is not preferable. On the other hand, when the content of cement exceeds 45 parts by mass, the stickiness is strong, the elongation and trowel separation are inferior, and the workability is poor. The preferred content of cement is 35 to 44 parts by mass, and more preferably 35 to 43 parts by mass.

[0014] As the anionic surfactant used in the repair material of the present invention, from the viewpoint of exhibiting high foaming properties in an alkaline environment, one or more selected from sulfonates, alkyl sulfates, alkyl ether sulfates, higher fatty acid salts, ether carboxylates, and acyl amino acid salts are preferable, and one or more selected from sulfonates, alkyl sulfates, alkyl ether sulfates, and ether carboxylates are more preferable. As the sulfonate, alpha olefin sulfonate, linear alkylbenzene sulfonate, alpha sulfo fatty acid methyl ester salt, etc. are preferable. From the viewpoint of obtaining good foaming properties, the anionic surfactant is preferably contained in the repair material of the present invention in an amount of 0.2 to 2.2 parts by mass, more preferably 0.3 to 1.5 parts by mass.

[0015] As the thickener used in the repair material of the present invention, from the viewpoint of retaining the foam generated by kneading the anionic surfactant and water and improving the workability with a trowel, a water-soluble thickener is preferable, and carrageenan, dextrin, water-soluble cellulose derivative, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, carboxyvinyl polymer, (acrylic acid / acrylic acid alkyl (C10-30)) copolymer, xanthan gum, carboxymethyl chitin, chitosan, and polyethylene oxide are more preferably one or more selected therefrom. Further, one or more selected from carrageenan, dextrin, water-soluble cellulose derivative, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, carboxyvinyl polymer, (acrylic acid / acrylic acid alkyl (C10-30)) copolymer, xanthan gum and polyethylene oxide are preferable. Here, examples of the water-soluble cellulose derivative include hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, etc. Further, as the polyethylene oxide, polyethylene oxide having a molecular weight of 60,000 to 7,000,000 is preferable. From the viewpoints of foam stability and improvement effect of trowel workability, the thickener is preferably contained in the repair material of the present invention in an amount of 0.1 to 3 parts by mass, more preferably 0.1 to 2 parts by mass.

[0016] In addition to the above components, the repair material of the present invention can contain rust inhibitors, fungicides, coloring pigments, adhesion improving components such as water-soluble polymer resin emulsions, etc.

[0017] It is advisable to premix each material dry using a mixer. Preferably, the raw materials are uniformly mixed at a factory in advance, packed in bags in fixed quantities, and then transported to the site for use as products. By premixing the materials before adding water, variations in fire resistance performance, plastering performance, etc. are reduced. Water is added to the premixed materials and kneaded to make a soft mortar for use. During kneading, it is preferable to use a mixer such as a mortar mixer, plasterer's mixer, hand mixer, or concrete mixer, as this results in a homogeneous mixture. The kneaded repair material is applied to the damaged areas of the fireproof coating using a trowel. This application method can be the same as that for general plaster mortar, especially for repair plaster mortar. When applying to damaged areas of the fireproof coating, it is preferable to pre-apply water or a water-soluble polymer resin emulsion to the damaged area to be applied, as this increases the adhesion between the damaged area of the fireproof coating and the repair material of the present invention.

[0018] Sprayed rock wool is the most suitable fireproof coating for the repair material of the present invention. By repairing the sprayed rock wool fireproof coating, a bulk density equivalent to that of sprayed rock wool and a low thermal conductivity can be ensured. Furthermore, for sprayed rock wool, an adhesiveness greater than the base material strength of sprayed rock wool can be ensured.

Examples

[0019] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[0020] Example 1 (Method) Weigh 1268.5 g of rock wool (manufactured by Taiheiyo Materials Co., Ltd.) and put it into a plastic bag. Put 713.5 g of cement (manufactured by Taiheiyo Cement Corporation), 8.0 g of hydroxypropyl methylcellulose (90EMP-4000, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), 2.0 g of polyethylene oxide (Alcox E-60, manufactured by Meisei Chemical Industry Co., Ltd.), and 8.0 g of sodium alpha-olefin (C14-C18) sulfonate (manufactured by Lion Specialty Chemicals Co., Ltd.) into this plastic bag, and shake and mix to make the materials uniform. Put the mixture into a soil mixer, and add 2.4 L of kneading water while stirring at a low speed (160 r.p.m.). Start measuring the stirring time from the time when the addition of the kneading water is completed. After stirring at a low speed (160 r.p.m.) for 30 seconds, stir at a high speed (330 r.p.m.) for 90 seconds. Fill a container with a known volume with the slurry, measure the weight, and calculate the slurry density. Based on the cement hydration water of 15% and the water ratio, calculate the estimated bulk density. If the estimated bulk density is about 0.28 g / cm 3 If it is at this level, stop stirring.

[0021]

Number

[0022] For Examples 2 to 7 and Comparative Examples 1 to 4, each component was used in the amounts described in Tables 1 and 2, and the procedures were carried out in the same manner as in Example 1 above. Fill the obtained slurry into a mold for forming a mortar specimen, scrape the surface to make the upper surface smooth, and cure indoors to produce a formed specimen. Using this specimen, the bulk density was measured according to the method for measuring the dry density specified in Section 8.4 of JIS A 1476:2016 Method for Measuring the Water Content of Building Materials.

[0023] Measurement of Adhesion The repair material of the present invention was sprayed and applied onto the blown rock wool to prepare a test piece. Next, after adhering an iron plate to the upper surface of the test piece, a push-pull gauge was connected to the iron plate and pulled vertically to measure the breaking load. The adhesion strength was calculated using the following formula from the breaking load and the cross-sectional area.

[0024] [Number]

[0025] Measurement of Thermal Conductivity Using JIS A 1412-2:1999 Method for Measuring Thermal Resistance and Thermal Conductivity of Thermal Insulating Materials - Part 2: Heat Flow Meter Method (HFM Method), the measurement temperature was set with the center temperature at 20°C and the temperature difference at 20°C for measurement.

[0026] Evaluation of Trowel Workability The repair material of the present invention was trowel - applied to an iron plate, and the workability (trowel elongation, trowel separation, trowel cut) at that time was evaluated. Trowel elongation is an evaluation of the degree to which the material spreads smoothly without breaking when the repair material is spread. Trowel separation is an evaluation of the degree of adhesion (stickiness) to the trowel when the repair material is spread up, down, left, and right. Trowel cut is an evaluation of the small amount of adhesion (trowel residue) to the trowel when the trowel is separated from the repair material after spreading the repair material. These were comprehensively judged and evaluated in four grades (◎: very good, 〇: good, △: ordinary, ×: poor).

[0027] (Results) The compositions and test results of Examples 1 - 7 and Comparative Examples 1 - 4 are shown in Tables 1 and 2. In the table, the '-' column indicates that the test was not conducted because the workability was poor.

[0028]

Table 1

[0029]

Table 2

[0030] From Tables 1 and 2, it can be seen that if the sprayed rock wool refractory coating is repaired using a kneaded refractory coating repair material containing 55 to 65 parts by mass of rock wool, 35 to 45 parts by mass of cement, 0.2 to 2.2 parts by mass of an anionic surfactant, and 0.1 to 3 parts by mass of a thickener, the bulk density equivalent to that of the sprayed rock wool and a low thermal conductivity can be ensured. Furthermore, it is possible to ensure an adhesiveness to the sprayed rock wool that is equal to or greater than the base material strength of the sprayed rock wool.

Claims

1. (A) 55 to 65 parts by mass of rock wool, (B) 35 to 45 parts by mass of one or more cements selected from Portland cement, white cement, blast furnace cement, super rapid hardening cement, and eco cement, (C) 0.2 to 2.2 parts by mass of one or more anionic surfactants selected from sulfonates, alkyl sulfates, alkyl ether sulfates, higher fatty acid salts, ether carboxylates, and acyl amino acid salts, and (D) 0.1 to 3 parts by mass of one or more thickeners selected from carrageenan, dextrin, water-soluble cellulose derivatives, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, carboxyvinyl polymer, (acrylic acid / alkyl acrylate (C10-30)) copolymer, xanthan gum, carboxymethyl chitin, chitosan, and polyethylene oxide. A kneaded refractory coating repair material.

2. The kneaded refractory coating repair material according to Claim 1, which is a repair material for a sprayed rock wool refractory coating.

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