JPH0521867B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to gaps created between fireproof and insulating bricks exposed to high temperatures in heating furnaces, etc., or between these and iron plates, and household appliances such as electric oven toaster. As a filling press-in material for insulation that can be easily filled with a pump or poured into spaces used to form insulation walls in products, or as insulation spraying construction material or troweling on various surfaces. The present invention relates to a monolithic refractory heat insulating material composition that can be widely used as a material and as a material for various heat insulating molding materials.

[Prior Art] For example, in the walls of a furnace exposed to high temperatures such as a heating furnace, cracks may occur between the heat insulating materials such as fireproof insulating bricks and ceramic fibers, or between these insulating materials and the road wall steel. In order to repair gaps and cracks, these gaps and cracks are filled with monolithic fireproof insulation material.

Examples of monolithic fireproof insulation materials used for this purpose include ceramic fiber bulk, powder fillers such as alumina powder, thickeners such as polyethylene oxide and carboxymethylcellulose (CMC), and colloidal fibers. A product prepared by dispersing or dissolving a binder such as alumina or colloidal silica in water at a predetermined ratio (Japanese Patent Application Laid-Open No. 57-67783
), ceramic fiber, colloidal silica, acrylic polymer, polyethylene oxide,
Products prepared by dispersing or dissolving adhesion promoters such as hydroxyethyl cellulose, CMC, and polyamide in a liquid vehicle such as water or lower alcohol in a predetermined ratio (Japanese Unexamined Patent Publication No. 1983-96608), ceramic fiber, and as a dispersant. polyethylene oxide, an inorganic binder consisting of colloidal silica or a mixture of this colloidal silica and colloidal alumina, and a stabilizer consisting of a nonionic activator, anionic activator, glycol, glycol ether, or a mixture thereof in a predetermined ratio. Dispersed in water (Japanese Unexamined Patent Publication No. 58-35380) is known.

However, the composition described in JP-A No. 57-67783 is a paste composition that is injected and filled into gaps and cracks by operating a syringe, and moreover, it contains powder fillers such as alumina powder, colloidal alumina, etc. Inorganic binders such as colloidal silica are blended, and as a result, the narrower the gaps and cracks become, the more difficult it becomes to fill the narrow spaces. When the ceramic fibers are pumped, the ceramic fibers coagulate and agglomerate in the piping, creating so-called lumps and causing piping blockage problems.Moreover, polyethylene oxide and carboxymethylcellulose (CMC)
Because of the use of thickeners such as, it has poor heat resistance and thermal shrinkage occurs under high-temperature conditions, making it difficult to fill densely.

In addition, the one described in Japanese Patent Application Laid-open No. 52-96608 is
Colloidal silica, which is insoluble in the liquid vehicle, is blended as an essential ingredient, and the
- Similar to the product described in Publication No. 67783, it is difficult to fill into narrow spaces, and when colloidal silica is used, the pH becomes 9 or higher, the dispersed fibers aggregate, and fluidity decreases, and the pump in the piping There is a problem that the pumpability deteriorates.Furthermore, the method described in Japanese Patent Application Laid-open No. 58-35380 also
It uses polyethylene oxide as a dispersant and an inorganic binder made of colloidal silica or a mixture of colloidal silica and colloidal alumina, and like the one described in JP-A-57-67783 mentioned above, It is difficult to fill into voids, and there are problems in that pumping performance in piping becomes poor.In addition, there is a problem in that it has poor heat resistance and shrinks under high temperature conditions, making it difficult to fill densely. .

[Problems to be Solved by the Invention] In view of the above, the inventors of the present invention have achieved excellent filling performance into narrow voids such as gaps and cracks, and pumping performance within piping, and moreover, the ability to heat shrink within gaps and cracks. As a result of intensive research into a monolithic fireproof insulation material composition that can reliably fill the voids without causing any Dispersed and blended at a specific ratio, it not only has excellent defibration and retention properties of inorganic fibers, but also improves fluidity and can be reliably filled into narrow spaces by pumping, as well as being effective in high-temperature ranges. It has been discovered that the material has excellent thermal expansion properties and can reliably fill voids, leading to the present invention.

Therefore, an object of the present invention is to provide a material that has excellent filling properties into narrow spaces such as gaps and cracks, and has excellent pumping performance in piping.
Moreover, it is an object of the present invention to provide a monolithic fireproof heat insulating material composition that can reliably fill gaps and cracks.

Another object of the present invention is to provide a manufacturing method for manufacturing a monolithic refractory heat insulating material composition having such excellent performance.

[Means for Solving the Problems] That is, the present invention uses 1 to 10 parts by weight of a water-soluble polyacrylic dispersion medium, 0.05 to 1 part by weight of a surfactant, and 200 to 500 parts by weight of water to 100 parts by weight of inorganic fibers. This is an amorphous fireproof and heat insulating material composition in which the above-mentioned inorganic fibers are uniformly dispersed in a defibrated state at a ratio of parts by weight. In addition, the present invention prepares a fibrillated dispersion of inorganic fibers by spraying water diluted with a surfactant on the inorganic fibers and defibrating the inorganic fibers with a Henshil mixer. A dispersion medium is dissolved or dispersed in water to prepare an aqueous dispersion medium, the above-mentioned defibrated dispersion of inorganic fibers and this aqueous dispersion medium are mixed to uniformly disperse and blend, and then deaerated. This is a method for producing a fireproof heat insulating material composition.

In the present invention, the inorganic fibers include rock wool,
Rock wool, also known as slag wool, mineral wool, silica/alumina ceramic fiber,
Examples include ceramic fibers such as mullite fibers, silica fibers, alumina fibers, zirconia fibers, and boron nitride fibers. Further, it is preferable to appropriately mix ceramic fiber with rock wool, since this has the effect of improving heat resistance and preventing reduction in shrinkage rate due to the entanglement of the two. In addition, when using rock wool, since the pH decreases and the rock wool tends to coagulate, add aluminum dihydrogen tripolyphosphate in advance as a calcium ion elution inhibitor in the range of 0.1 to 6 parts by weight per 100 parts by weight of rock wool. It is preferable to keep it. These inorganic fibers can be used either in a non-fibrillated state or in a defibrated state, but from the viewpoint of cost, it is preferable to use fibers in a non-fibrillated state. It is better to do so.

In addition, the water-soluble polyacrylic dispersion medium used in the present invention is necessary for maintaining a matrix effect that maintains the inorganic fibers in a uniformly dispersed state and for maintaining good fluidity and heat resistance during construction.
There is no need for substances with so-called adhesive properties; for example, metal salts of polyacrylic acid such as sodium polyacrylate and potassium polyacrylate, alkali salts of polyacrylic acid such as ammonium polyacrylate, polyacrylamide, acrylic acid and acrylic acid. Examples include copolymers with alkali salts. In particular, from the viewpoint of water solubility and heat resistance, polyacrylic acid alkali salts are preferred, and sodium polyacrylate is more preferred.

Furthermore, the surfactant used with this water-soluble polyacrylic dispersion medium is essential for defibrating inorganic fibers and preventing fiber aggregation, and includes, for example, alkali salts of higher fatty acids, alkyl sulfates,
Anionic surfactants such as alkyl sulfonates and alkylaryl sulfonates, cationic surfactants such as higher amine halogenates and quaternary ammonium salts, and nonionic surfactants such as polyethylene glycol alkyl ethers and polyethylene glycol fatty acid esters. surfactants, amphoteric surfactants such as amino acids, etc., and one or more of these may be used as appropriate depending on the type of inorganic fiber used and the type of water-soluble polyacrylic dispersion medium. Can be used selectively. In addition, when the inorganic fiber is a ceramic fiber, preferably an anionic surfactant, more preferably sodium alkylbenzenesulfonate. Further, when the inorganic fiber is rock wool, it is preferable to add the cationic fiber and the anionic fiber in two steps. That is, first, an alkylamine type cationic surfactant is added, and after preliminary defibration, an anionic surfactant is added to perform defibration treatment. The primary defibration softens the fibers and has the effect of improving the degree of defibration in the secondary defibration.

Regarding the blending ratio of the amorphous fireproof heat insulating material composition of the present invention, the water-soluble polyacrylic dispersion medium is 1 to 10 parts by weight, preferably 2 to 6 parts by weight, per 100 parts by weight of inorganic fibers, and Activator is 0.05-1
Parts by weight, preferably 0.1 to 0.5 parts by weight, and 200 to 500 parts by weight, preferably 300 to 450 parts by weight of water. Regarding the amount of water-soluble polyacrylic dispersion medium used, if it is too small, it will not function as a dispersion medium, and on the other hand, if it is too large, it will not only increase costs but also reduce fluidity and cause it to flow into narrow voids. The filling property etc. of the product deteriorates. Regarding the amount of surfactant used, if it is too small, it will not function as a dispersant, and if it is too large, the inorganic fibers may aggregate. Furthermore, if the amount of water used is too small, the viscosity will become too high and the ability to fill narrow voids will be reduced, while if it is too large, the viscosity will be too small, causing the problem of sagging during use. The amount of water used should be adjusted within the above range depending on the purpose and method of use. For example, when press-fitting material into a narrow gap, it is recommended to use a larger amount of water. On the other hand, when using it as a molding material, it is better to use less water. In order to improve the heat resistance of the composition of the present invention, especially when the inorganic fiber is a ceramic fiber, 1 to 10% by weight of alumina sol (neutral) is added to the entire composition. ,
Preferably, it can be blended in an amount of 4 to 8% by weight.

The monolithic fireproof heat insulating material composition of the present invention having such a composition has a press-in load of usually 0.3 kg/cm ² ·G or less, preferably 0.2 to 01 kg/cm ² ·G, in the load fluidity test shown below, for example. If this press-fitting load exceeds 0.3 kg/cm ²・G,
In particular, the pumping performance within the flexible tube deteriorates, and when pumping with a pump such as a snake pump, a rubber hose with a diameter of about 10 mm, for example, may become clogged. In addition, in this load fluidity test, the monolithic refractory insulation composition was placed in a cylinder with a length of 300 mm x 30 mmφ that had an outlet with a size of 3 mmφ at the bottom from the outlet.
Charge the monolithic refractory insulation composition to a height of 200 mm, press the monolithic refractory insulation composition from above with a piston with a diameter of 28 mm, measure the load when the monolithic refractory insulation composition begins to flow out from the outlet, and The value is evaluated as a press-in load, and the load at this time is usually measured with the entire device placed on a scale.

Next, in order to prepare the amorphous fireproof insulation material composition of the present invention, the above-mentioned inorganic fiber, water-soluble polyacrylic dispersion medium, surfactant, and water are blended in a predetermined ratio, and the composition is prepared using a rotary blade. The mixture may be uniformly kneaded by using a suitable kneader whose rotational speed can be adjusted, preferably a Henshil mixer, and preferably by the following procedure.

First, using a Henshil mixer, the total amount of inorganic fibers, the total amount of surfactant, and 15 to 60% by weight, preferably 20 to 50% by weight of water, are mixed at a rotation speed of 1000.
5-20 at ~2000rpm, preferably 1200-1500rpm
The mixture is kneaded for 5 to 10 minutes, preferably 5 to 10 minutes, to prepare an inorganic fiber dispersion in which the inorganic fibers have been defibrated.
If the rotation speed is too low, poor defibration will occur, if it is too high, fiber granulation will occur and cause lumps, and if the kneading time is too short, the dispersion and penetration of the surfactant will be insufficient. This can cause clumps, and on the other hand, if it is too long, the fibers will become granulated and cause clumps.

Further, the entire amount of the water-soluble polyacrylic dispersion medium is added to the remaining water and mixed for 3 to 10 minutes, preferably 5 to 8 minutes, using a means such as a hand mixer, to prepare an aqueous dispersion medium. If the mixing time at this time is less than 3 minutes, there is a risk of forming lumps;
Even if the mixture is mixed for more than a minute, there is no significant change.

Next, the inorganic fiber dispersion and aqueous dispersion medium prepared in this manner are charged into a kneader, preferably a Henshil mixer, and kneaded at a rotation speed of 1000 to 1500 rpm for 3 to 10 minutes. Then the rotation speed is 200~
500rpm, vacuum degree 600-700mmHg, preferably 650
Degassing is performed under conditions of approximately mmHg and treatment time of 3 to 10 minutes, preferably 4 to 6 minutes. Too little kneading time will result in insufficient uniformity; too long kneading time will result in excessive tackiness. In addition, by degassing, the air bubbles in the composition are reduced and the density is 1.0 to 1.15.
g/cm ² , which improves the pumping performance within the piping.

The monolithic refractory heat insulating material composition of the present invention can be used as a repair material for voids such as gaps and cracks that occur in the walls of a heating furnace, etc., and as a repair material for damaged areas that occur on the surface of such a furnace wall, such as for electrical appliances. It can be used for many purposes, such as a molding material for forming heat insulating walls in home appliances such as toaster ovens, and can be adjusted to be easy to use according to each purpose.
That is, for example, when using the voids as a repair material for gaps, cracks, etc. that occur in the walls of a furnace such as a heating furnace, the monolithic refractory heat insulating material composition of the present invention can be used as is as a filling press-in material, a pouring material, etc. . For example, when using the monolithic refractory heat insulating material composition of the present invention as a material for correcting damage caused on the surface of a furnace wall, the monolithic refractory heat insulating material composition of the present invention may be used as is or with a suitable heat-resistant binder, such as neutral colloidal alumina or neutral phosphor. After adjusting the viscosity to an appropriate level by adding an acid amine binder, it can be used as a spraying material, a troweling material, etc. Furthermore, when used as a molding material for molding a heat insulating wall, the monolithic fireproof heat insulating material composition of the present invention may contain aggregates such as alumina powder, silica powder, viscosity, etc., and colloidal alumina, phosphoric acid binder, etc. It can be used as a press molding material, an extrusion molding material, etc. by adding and blending a heat resistant binder, and if necessary, a heat resistant inorganic molded body can be produced by baking treatment after molding.

Furthermore, when colloidal silica is used in the amorphous fire-insulating composition of the present invention, if the inorganic fiber is a ceramic fiber, aggregation of the fibers occurs due to a change in the zeta potential due to an increase in the pH, resulting in the formation of lumps. In addition, when the inorganic fiber is rock wool, the PH increases, which causes fiber aggregation and clumps.
For this reason, when the inorganic fiber is ceramic fiber, it is better to use colloidal alumina, and when the inorganic fiber is rock wool, it is recommended to increase the amount of aluminum dihydrogen tripolyphosphate used during defibration. Good. The amount used when these colloidal aluminas are blended and the ratio when increasing the amount of aluminum dihydrogen tripolyphosphate is 1% to the entire composition.
-20% by weight, preferably 1-10% by weight.

[Function] In the present invention, the combined use of a water-soluble polyacrylic dispersion medium and a surfactant provides a matrix effect that maintains the defibrated inorganic fibers in a uniformly dispersed state, thereby improving their fluidity. This improves pumping performance and other effects.

[Examples] The present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 Undefibrated ceramic fiber (product name: Nippon Steel Chemical Co., Ltd.) was placed in a Henshil mixer with a capacity of 500.
S-Fiber SC1260) 30Kg, water 51Kg, and sodium alkylbenzenesulfonate as a surfactant (product name: Neoperex F-25, manufactured by Kao Corporation)
0.08 kg and kneaded under the conditions of a rotation speed of 1500 rpm and a processing time of 8 to 10 minutes to prepare an inorganic fiber dispersion.

On the other hand, 1 sodium polyacrylate in 80 kg of water
Kg was added and stirred for 7 minutes to prepare an aqueous dispersion medium in which the sodium polyacrylate was dissolved.

Next, the aqueous dispersion medium prepared in this manner was added to a Henshil mixer containing the prepared inorganic fiber dispersion, and kneaded at a rotation speed of 1500 rpm and a processing time of 5 minutes, and then continued to be rotated. number
Deaeration treatment was performed under the conditions of 300 rpm, vacuum degree of 650 mmHg, and treatment time of 5 minutes to prepare a fireproof insulation material composition.

The fireproof insulation material composition of this example has fibers in the form of paste, a density of 1.12±0.02 g/ ^m3 , and a consistency (JIS R-
2506) was 320±10.

In addition, a load fluidity test was conducted on this fireproof insulation material composition, and the press-in load was 0.16Kg/
cm ²・G, and 200~ by direct reading dilatometer.
The thermal expansion coefficient measured in a temperature range of 1000°C was as shown in Figure 1.

The fireproof insulation material composition of this example was subjected to a nonflammability test according to JIS A 1321 method, and both the smoke generation test and exhaust gas temperature met the standards, and the product passed the test as a noncombustible material. was confirmed.

Comparative Example 1 Except for using carboxymethyl cellulose (CMC) in place of sodium polyacrylate,
A fireproof heat insulating material composition was prepared in the same manner as in Example 1, and the press-in load and hot expansion coefficient were measured in the same manner as in Example 1 by a load fluidity test. The press-fitting load was 0.41 kg/cm ² ·G or more, and the coefficient of hot expansion was as shown in FIG.

Comparative Example 2 A fireproof insulation material composition was prepared in the same manner as in Example 1 above, except that polyethylene oxide (PEO) as a thickener was used instead of sodium alkylbenzenesulfonate as a surfactant,
In the same manner as in Example 1, the press-in load and thermal expansion coefficient were measured by the load flow test. The results showed that the press-fitting load was 1.3 kg/cm ² ·G or more, and the coefficient of hot expansion was as shown in FIG.

Comparing the results of this press-fitting load with the case of the fireproof insulation composition of Example 1, in the case of Example 1 it is 0.16
Kg/cm ²・G, which is about 1/of that of Comparative Example 2.
10, and it was found that the fireproof heat insulating composition of Example 1 was extremely superior to the one of Comparative Example 2 in filling properties into narrow spaces and pumping properties in piping.

Furthermore, as is clear from the thermal expansion coefficient results shown in Figure 1, in the case of the fireproof and insulating composition of Comparative Example 2, its volume contracts up to a heating temperature of 800°C. , in the fireproof insulation composition of Example 1, contrary to Comparative Example 2,
The volume expands little by little up to a heating temperature of 800°C, and the fireproof insulation composition of Example 1 has excellent filling properties for voids in a high temperature range compared to that of Comparative Example 2. It turned out that it shows.

Comparative Example 3 The press-in load was measured by the load fluidity test in the same manner as in Example 1 above, except that a commercially available inorganic heat insulating filler was used as the fireproof heat insulating material. Result is
It was 0.4Kg/cm ²・G.

[Effects of the Invention] The monolithic fireproof insulation material composition of the present invention exhibits excellent dispersibility in water, can be reliably filled into narrow voids, has excellent pumpability in piping, and has high temperature resistance. It has excellent thermal expansion properties in the wide range of areas and can reliably fill voids, and is useful for manufacturing press-fitting materials, pouring materials, spraying materials, or troweling materials for insulation, as well as various insulation materials. According to the method of the present invention, it is possible to easily produce a monolithic refractory heat insulating material composition having such excellent performance.

[Brief explanation of drawings]

FIG. 1 is a graph showing the coefficient of thermal expansion of the monolithic refractory heat insulating material compositions of Examples and Comparative Examples.

Claims (1)

[Claims] 1. 1 to 10 parts by weight of water-soluble polyacrylic dispersion medium and 0.05 parts by weight of surfactant per 100 parts by weight of inorganic fiber.
1. A monolithic refractory heat insulating material composition, characterized in that the inorganic fibers are uniformly dispersed in a defibrated state at a ratio of ~1 part by weight and 200 to 500 parts by weight of water. 2. A defibrated dispersion of inorganic fibers is prepared by spraying water diluted with a surfactant on inorganic fibers and defibrating them with a Henshil mixer, and
A water-soluble polyacrylic dispersion medium is dissolved or dispersed in water to prepare an aqueous dispersion medium, and the defibrated dispersion of the inorganic fibers and this aqueous dispersion medium are mixed to be uniformly dispersed, and then decomposed. A method for producing a monolithic fireproof insulation material composition, which comprises air treatment.