JPH02175669A - Unshaped refractory heat insulating material composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in filling properties into narrow voids, such as gaps or cracks, or pressure pumping properties in pipes by homogeneously dispersing and blending a water-soluble polyacrylic dispersion medium, surfactant and water in respective specific proportions with inorganic fiber in a disaggregated state thereof. CONSTITUTION:An unshaped refractory heat insulating composition containing 1-10 pts.wt. water-soluble polyacrylic dispersion medium, 0.05-1 pt.wt. surfactant and 200-500 pts.wt. water homogeneously dispersed and blended in 100 pts.wt. inorganic fiber consisting of rock wool, such as rock fiber or slag, in a disaggregated state is provided. The above-mentioned composition is produced by kneading the aforementioned blend in a kneader having rotating blades capable of regulating number of revolutions. The above-mentioned composition is then subjected to deaeration treatment under conditions of, e.g. 200-500 r.p.m. number of revolutions and 600-700mmHg vacuum degree. Thereby, the aforementioned unshaped refractory heat insulating material composition, having the above-mentioned characteristics and further capable of surely filling void parts in gaps or cracks thereof is obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is applicable to gaps created between fireproof and insulating bricks exposed to high temperatures such as in heating furnaces or between these and iron plates, and household appliances such as electric oven toasters. It can be used 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 electrical products, or as a construction material or trowel for spraying insulation onto various surfaces. The present invention relates to a monolithic fireproof heat insulating material composition that can be widely used as a coating 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 insulation materials such as fireproof insulation bricks and ceramic fibers, or between these insulation materials and the furnace wall steel. In order to repair gaps and cracks, these gaps and cracks are filled with monolithic fireproof insulation material.

Examples of monolithic fire-resistant insulation materials used for this purpose include ceramic fiber bulk, powder fillers such as alumina powder, and thickeners such as polyethylene oxide and carboxymethylcellulose (CMC). , a binder such as colloidal alumina or colloidal silica dispersed or dissolved in water at a predetermined ratio (JP-A-57-67-783), ceramic fiber, colloidal silica, acrylic polymer, Products prepared by dispersing or dissolving an adhesion promoter such as polyethylene oxide, hydroxyethyl cellulose, CMC, or polyamide in a liquid vehicle such as water or lower alcohol in a predetermined ratio (Japanese Unexamined Patent Publication No. 52-96-608), ceramic fibers, polyethylene oxide as a dispersant, an inorganic binder consisting of colloidal silica or a mixture of this colloidal silica and colloidal alumina, a nonionic activator,
One known is one in which an anion activator, a glycol, a glycol ether, or a stabilizer consisting of a mixture thereof is dispersed in water at a predetermined ratio (Japanese Patent Application Laid-open No. 35,380/1980).

However, the composition described in JP-A-57-67, 783 is a paste composition that is injected and filled into gaps and cracks by operating a syringe, and moreover, it uses powder fillers such as alumina powder and colloidal fillers. Inorganic binders such as alumina and rhoidal 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 tube is pumped, ceramic fibers coagulate and agglomerate inside the pipe, creating so-called lumps and causing problems with pipe clogging.Moreover, thickeners such as polyethylene oxide and carboxymethyl cellulose (CMC) are used. Therefore, there is a problem that 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. 52-96,608 is
Colloidal silica, which is insoluble in the liquid vehicle, is blended as an essential component, and is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 57-67, 7.
Similar to the one described in Publication No. 83, it is difficult to fill into narrow spaces, and when colloidal silica is used, the pH is 9.
As a result, the dispersed fibers aggregate and fluidity decreases.
Furthermore, the method described in JP-A-58-35380 also uses polyethylene oxide as a dispersant and colloidal silica, or a mixture of this colloidal silica and colloidal alumina. This method uses an inorganic binder similar to that described in JP-A-57-67-783 (it is difficult to fill into narrow spaces, and the pumping performance in piping is poor. In addition to the problem of poor heat resistance, there is also the problem of thermal shrinkage 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 in a specific ratio, it not only has excellent defibration properties and retention properties of inorganic fibers, but also improves fluidity and can be reliably filled into narrow spaces by pumping. 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 monolithic refractory that has excellent filling performance into narrow voids such as gaps and cracks, and has excellent pumping performance in piping, and which can reliably fill voids within gaps and cracks. An object of the present invention is to provide a heat insulating material composition.

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

In the present invention, inorganic fibers include rock wool, slag wool, slag wool, etc., silica/alumina ceramic fiber, mullite fiber,
Examples include ceramic fibers such as silica fibers, alumina fibers, zirconia fibers, and boron nitride fibers. Further, it is preferable to appropriately mix ceramic fibers with rock wool, since this has the effect of improving heat resistance and preventing reduction in shrinkage rate due to intertwining of the two. When using rock wool, the pH decreases and the rock wool tends to aggregate, so add 0.1 to 6 weight of aluminum dihydrogen tripolyphosphate to 100 parts of rock wool as a calcium ion elution inhibitor in advance. It is preferable to add the amount within the range of 100%. 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 the matrix effect of maintaining the inorganic fibers in a uniformly dispersed state and for maintaining good fluidity and heat resistance during construction. There is no need for substances that have so-called adhesive properties, such as sodium polyacrylate,
Examples include metal salts of polyacrylic acid such as potassium polyacrylate, alkali salts of polyacrylic acid such as ammonium polyacrylate, polyacrylamide, and copolymers of acrylamide and alkali salt of acrylic acid. In particular, from the viewpoint of water solubility and heat resistance, polyacrylic acid alkali salts are preferred, and sodium polyacrylate is more preferred.

In general, surfactants used with this water-soluble polyacrylic dispersion medium are essential for defibrating inorganic fibers and preventing fiber aggregation. 7-ion surfactants such as sulfonates and alkylaryl sulfonates,
Examples include cationic surfactants such as higher amine halogenates and quaternary ammonium salts, nonionic surfactants such as polyethylene glycol alkyl ethers and polyethylene glycol fatty acid esters, and amphoteric surfactants such as amino acids. , these vary depending on the type of inorganic fiber used, the type of water-soluble polyacrylic dispersion medium, etc.
One species or two or more species can be appropriately selected and used. In addition, when the inorganic fiber is a ceramic ivy fiber, an anionic surfactant is preferably used, and sodium alkylbenzenesulfonate is more preferably used. 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 secondary 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 insulation material composition of the present invention, the water-soluble polyacrylic dispersion medium is 1 to 10 parts by weight, preferably 2 to 6 heavy chains, per 100 parts by weight of inorganic fibers, The surfactant is 0.05 to 1 part by weight, preferably 0.1 to 0.5 parts by weight, and the water is 200 to 50 parts by weight.
0 parts by weight, preferably 300 to 450 parts by weight. 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. It is best to adjust the amount of water used 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 a smaller amount of 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 4 to 8
It can be blended within a range of weight %.

The monolithic refractory heat insulating material composition of the present invention having such a composition can be tested, for example, in the following load fluidity test (injection load is usually 0.3 Ky/crtt-G or less, preferably 0.2 to It is within the range of 0.IK/cni・G, and if this press-fitting load exceeds 0.3Kg/~・G, the pumping performance in piping, especially in flexible tubes, will decrease,
When pumping with a pump such as a snake pump, for example, a problem of clogging may occur with a rubber hose of about 10 mφ. In addition, this load fluidity test was carried out at a distance of 3 m below.
Length 300mm x 30m with outlet of mφ size
The monolithic refractory insulating material composition is charged into a cylinder with a diameter of mφ to a height of 200 m from the outlet, and the monolithic refractory insulating material composition is pressed from above with a piston with a diameter of 28 mmφ, and The load at which the monolithic refractory insulation composition begins to flow out is measured, and that value is evaluated as the press-in load.The load is usually measured by placing the entire device on a scale. done in the state.

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 and the total amount of surfactant are mixed with 15 to 60% by weight, preferably 20 to 50% by weight of water, at a rotation speed of 1.000 to 2.
OOOrpm, preferably 1°200~1.500r
Kneading at pm for 5 to 20 minutes, preferably 5 to 10 minutes,
An inorganic fiber dispersion in which inorganic fibers are defibrated is prepared. If the rotation speed is too low, poor defibration will occur, while if it is too high, fiber granulation will occur and cause lumps.
If the kneading time is too short, the dispersion and permeation of the surfactant will be insufficient, causing lumps, while if the kneading time is too long, the fibers will be granulated, causing lumps.

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. In this case, if the mixing time is less than 3 minutes, there is a risk of formation of lumps, and on the other hand, if the mixing time is longer than 10 minutes, there will be no significant change.

Next, the inorganic fiber dispersion thus prepared and the aqueous dispersion medium were placed in a mixer, preferably a Henschel mixer, and heated at a rotational speed of 1,000 to 1°500 rl) m for 3
After kneading for ~10 minutes, the number of revolutions is 200-500.
ppm, degree of vacuum 600-700mHO1 preferably 6
Degassing is performed under conditions of approximately 50 mmH (If) and a treatment time of 3 to 10 minutes, preferably 4 to 6 minutes. If the crosstalk time is too short, the uniformity will be insufficient, and if it continues for a long time, the tackiness will become excessive. In addition, by degassing, the air bubbles in the composition are reduced and the density is 1.0 to 1.159/cffl.
This 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 depending on the purpose. That is, when used as a repair material for voids such as gaps and cracks that occur in the walls of a heating furnace, etc., the monolithic fireproof and 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 used as a repair material for damaged parts 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 blending with an acid amine binder and adjusting the viscosity to an appropriate level, it can be sprayed and used as a construction material, troweling material, etc.

In addition, when used as a molding material for forming a heat insulating wall, the monolithic fireproof heat insulating material composition of the present invention may be combined with aggregates such as alumina powder, silica powder, clay, etc., and rhoidal alumina, phosphoric acid. It can be used as a material for press molding, a material for extrusion molding, etc. by adding and blending a heat-resistant binder such as a system binder, and if necessary, a heat-resistant inorganic molded body can be produced by performing a firing treatment after molding.

Note that when colloidal silica is used in the amorphous fireproof insulation material composition of the present invention, if the inorganic fibers are ceramic fibers, the I)H increases and the sweater potential changes, causing fiber aggregation and clumps. It causes the occurrence of
In addition, when the inorganic fiber is rock wool, the pH
As a result of this increase, fiber aggregation occurs, causing lumps. For this reason, if the inorganic fiber is ceramic fiber, it is better to use colloidal alumina, and if the inorganic fiber is rock wool, increase the amount of aluminum dihydrogen tripolyphosphate used during defibration. It is better. The amount used when blending these colloidal aluminas and the proportion when increasing the amount of aluminum dihydrogen tripolyphosphate are within the range of 1 to 20% by weight, preferably 1 to 10% by weight based on the entire composition. Good.

[Function] In the present invention, the combined use of a water-soluble polyacrylic dispersion medium and a surfactant exhibits a matrix effect that maintains the defibrated inorganic fibers in a uniformly dispersed state, thereby improving their fluidity. However, effects such as pumpability are exhibited.

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

Example 1 Undefibrated ceramic fiber (product name: S-Fiber 5C1260 manufactured by Nippon Steel Chemical Co., Ltd.) was placed in a Henshil mixer with a capacity of 500 g. j, 51 kg of water, and 0.08 sodium alkylbenzene sulfonate (trade name: Neoperex F-25 manufactured by Hanadama ■) as a surfactant.
Kg, rotation speed 1.5001...and processing time 8
The mixture was kneaded for ~10 minutes to prepare an inorganic fiber dispersion.

On the other hand, Ikg of sodium polyacrylate in 80kg of water
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 thus prepared was added to a Henshil mixer containing the prepared inorganic fiber dispersion, and kneaded at a rotation speed of 1.50 rpm and a processing time of 5 minutes. Continue to rotate at 30 rpm and vacuum level at 65.
Deaeration treatment was performed under the conditions of 0 mmHg and treatment time of 5 minutes to prepare a fireproof heat insulating material composition.

In the fireproof insulation material composition of this example, the fibers are paste-like, the density is 1.12±0.02g/'IIi, and the consistency measured by a penetrometer (JIs R-2
506) was 320±10.

In addition, a load fluidity test was performed on this fireproof insulation material composition, and the press-in load was 0.1611 i'g/c.
tl-G, and 200 to 1 with a direct reading inflation needle.
The thermal expansion coefficient measured in a temperature range of ,000°C was as shown in FIG.

Regarding the fireproof insulation material composition of this example, JIS
The results of the nonflammability test using the A1321 method showed that both the smoke generation test and the exhaust gas temperature met the standards, and it was confirmed that the product passed the test as a noncombustible material.

Comparative Example 1 A fireproof insulation material composition was prepared in the same manner as in Example 1, except that carboxymethyl cellulose (CMC) was used in place of sodium polyacrylate, and the load fluidity test was conducted in the same manner as in Example 1. The press-fit load and hot expansion coefficient were measured. The press-fitting load was 0.42 kg/car-G or more, and the coefficient of hot expansion was as shown in FIG. 1.

Comparative Example 2 A fireproof insulation material composition was prepared in the same manner as in Example 1 above, except that polyethylene oxide (PEO) was used in place of sodium alkylbenzenesulfonate, and its load fluidity test was conducted in the same manner as in Example 1. The press-fit load and hot expansion coefficient were measured. Press fit load is 1.3Kg/ci
-G or more, and the coefficient of thermal expansion was as shown in FIG.

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. The result is 0.4 Kg/cr
It was tt-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 area and can reliably fill voids, and is suitable for press-fitting, pouring, and spraying for insulation, as a construction material or troweling material, and when manufacturing 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 the drawing]

FIG. 1 is a graph showing the coefficient of thermal expansion of the monolithic refractory heat insulating material compositions of Examples and Comparative Examples. Patent applicant: Nippon Steel Chemical Co., Ltd.

Claims (2)

[Claims] (1) 1 to 10 parts by weight of water-soluble polyacrylic dispersion medium and 0.05 to 100 parts by weight of surfactant per 100 parts by weight of inorganic fibers
1 part by weight and 200 to 500 parts by weight of water, and
A monolithic fireproof insulation material composition characterized in that the above-mentioned inorganic fibers are uniformly dispersed and blended in a defibrated state. (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 also added. It is characterized by preparing an aqueous dispersion medium by dissolving or dispersing it in water, mixing the defibrated dispersion of the inorganic fibers and this aqueous dispersion medium to uniformly disperse and blend, and then degassing. A method for manufacturing a monolithic fireproof insulation material composition.