JPH0961061A - Bake repairing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bake repairing material to be used in hot-repairing for a lining of a refractory material in which a superior thermal transferring characteristic, a filling characteristic and a superior prevention of aging variation are attained. SOLUTION: This bake repairing material contains novolak type phenolic resin of 7 to 17wt.%, solvent of 7 to 17wt.% and oily liquid silicone resin of 0.05 to 5wt.% based on 100wt.% of the refractory aggregate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baked repair material used for hot repair of refractory linings of various high temperature kilns.

[0002]

2. Description of the Related Art Baking repair is a method for hot repairing local damage such as a converter, a ladle, a tundish, and a blast furnace gutter. The repair material used for this purpose is put in a repaired part in a bag and baked by the residual heat of the furnace wall.

Repair materials can be classified into water-based and non-water-based. Immediately before use, the water-based material is kneaded in water and put in a sludge state before putting it into a bag for use. The material of the bag is heat-dissipative synthetic resin, paper, or the like. However, since the water system requires hydro-kneading before repairing, the kneading work in front of the furnace is forced, and quick repair cannot be performed.

On the other hand, the non-aqueous system uses tar pitch or phenol resin as a binder, and can be kneaded in advance, so that the kneading work in front of the furnace is not required, but the binder is hardened. Since it is slow, it takes time to complete the baking.

As a remedy for this problem in non-aqueous systems,
A liquid polyhydric alcohol is added to improve the fluidity so that the repaired portion can be quickly filled (Japanese Patent Laid-Open No. 63-156081). Self-fluidity at room temperature using a liquid novolac type phenol resin. Baking material provided with (Japanese Patent Application Laid-Open No. 3-126679, Japanese Patent Application Laid-Open No. 3-2711)
No. 68) has been developed.

[0006]

However, a material exhibiting fluidity at room temperature is a material which is subjected to vibration during transportation from a manufacturing site to a use site, sedimentation of coarse aggregate due to a lapse of time during storage, or floating of a liquid content. Solid-liquid separation due to. When the solid-liquid separated material is put into the repaired part, the aggregate sedimentation layer in the form of aggregate is difficult to deform, resulting in poor filling property. Moreover, the aggregated sedimentation layer that has become a lump easily peels off due to the external force received during use. In addition, a liquid layer is formed on the surface due to the sedimentation of the aggregate, and the corrosion resistance is poor.

Regarding the improvement of this problem, Japanese Patent Laid-Open No. 3-1
In Japanese Patent No. 26679, it is proposed to add an organic separation inhibitor having a melting point or a softening point of 50 ° C. or higher, but the separation inhibitor is solid at room temperature and has a low specific gravity, so that it has a fluidity. There is a problem that it is inferior and the filling property is lowered.

Further, Japanese Patent Laid-Open No. 3-271168 discloses that
It has been proposed to limit the number average molecular weight of the novolac type phenolic resin used as a binder to 600 or less to improve the adhesive strength. However, a low molecular weight phenol resin has a drawback in that the carbon bond due to polycyclization and polycondensation is remarkably slow, so that the characteristic of the phenol resin that the heat curing is fast cannot be utilized.

[0009]

DISCLOSURE OF THE INVENTION The present invention is a baking repair material used for hot repair of refractory lining, which solves the above-mentioned conventional problems. As described in.

The first aspect of the present invention is 100 wt% of refractory aggregate.
On the other hand, by externally hanging, novolac type phenol resin 7-1
It is a baking repair material containing 7 wt%, a solvent 7 to 17 wt% and an oily liquid silicone resin 0.05 to 2 wt%.

The silicone resin is a chlorosilane derivative R
_n SiCl _(4-n) hydrolysis, polycondensation,
It has a three-dimensional mesh structure. Since the synthesized silicone resin has a large molecular weight, it has high viscosity. Commercially available types are thinned with degreased powder, 100% liquid having a relatively low degree of polymerization, and other liquids. When diluted with liquid, the liquid is further divided into oily and aqueous. Of these, the present invention uses an oily liquid silicone resin.

The oily liquid silicone resin is one dissolved in toluene, xylene, mineral spirit, kerosene, etc., and has a silicone resin content of 5 wt% or more, usually 10%.
~ 60 wt%. It can be considered that the use of the oily liquid silicone resin emulsifies the binder composed of the novolac type phenolic resin and the solvent to obtain the effect of suppressing the sedimentation of the aggregate in the present invention.

On the other hand, an aqueous solution obtained by dissolving a silicone resin in water solidifies a phenol resin, which is not preferable. Further, a powder or a 100% liquid silicone resin having a low degree of polymerization has a poor dispersibility in a solvent of a phenol resin, so that an effect of suppressing sedimentation of an aggregate cannot be obtained.

The addition of paper fibers in the present invention is more effective in preventing solid-liquid separation. That is, use of a highly viscous liquid is generally considered to prevent solid-liquid separation, but a viscous liquid hinders fluidity at room temperature. On the other hand, the addition of paper fibers improves the viscosity even with a liquid having a low viscosity, and is effective in preventing solid-liquid separation without impeding the fluidity.

Further, since the paper fibers are dispersed in the repair material, volatile components such as a solvent are easily transmitted through the fibrous substance and easily deaerated. As a result, there is an effect of shortening the curing time. The paper fiber also has an effect that the fluidity at room temperature and the tackiness to the extent that solid-liquid separation is suppressed can be easily adjusted by adjusting the addition amount thereof.

In the present invention, when the refractory aggregate is further coated with the oily liquid silicone resin, it is also excellent in suppressing solid-liquid separation during long-term storage of the baked repair material.
This is presumably because this coating prevents contact between the solvent of the phenol resin and the refractory aggregate.

The refractory aggregate used in the present invention is basic,
Either neutral or acidic can be used. The basic material is, for example, magnesia, magnesia-calcia, dolomite, or the like. Examples of the acidic or neutral material include silica, zircon, alumina and the like. Further, if necessary, a carbonaceous material such as graphite, pitch, carbon black or the like may be added to improve corrosion resistance. In addition, for the purpose of preventing oxidation of carbon bonds and improving hot strength, a small amount of metal powder such as Al, Si, Mg and alloys thereof may be added. Metal fibers or ceramic fibers may be added for the purpose of improving wear resistance.

The particle size of the refractory aggregate may be the same as that of the conventional baking material, for example, 20 to 50 w of fine powder of 0.1 mm or less.
It is preferable to design the maximum particle size to be about 3% to about 5 mm with a t% of about.

The phenol resin is classified into a novolac type and a resol type, but the novolac type is used in the present invention. The novolac type phenol resin forms a carbon bond while forming a ring structure with a dehydration reaction of the OH group of the phenol nucleus in the range of 300 ° C to 600 ° C, and strengthens the repair material structure. The addition amount of the novolac-type phenol resin is an external amount with respect to 100 wt% of the refractory aggregate. If it is less than 7 wt%, the carbon bond strength becomes insufficient, and if it exceeds 17 wt%, the curing rate becomes slow and the workability is poor.

The resol type phenolic resin has poor heat softening and fluidity at high temperature and is inferior in the denseness of the structure of the baked material after repairing, but taking advantage of the characteristic of thermosetting, the refractory aggregate 100 wt
When it is added together with the novolac type phenolic resin in the range of 5 wt% or less in terms of external ratio to%, the curing time can be shortened without inhibiting the heat fluidity of the baking repair material. The resol-type phenol resin may be dissolved in a solvent and added, or may be used in a solid form.

The solvent has a role of dissolving the phenol resin. As a specific type, a polyhydric alcohol such as ethylene glycol, diethylene glycol, triethylene glycol or propylene glycol is used. The amount of addition is 7 to 17 when applied to 100 wt% of refractory aggregate.
wt%, and within this range, in accordance with the number average molecular weight of the novolac type phenolic resin, the type of solvent, or the hot fluidity required by the atmosphere temperature of the kiln to be repaired,
Determine to provide room temperature fluidity. Fireproof aggregate 100
If the addition of less than 7 wt% is applied to the wt%, it is difficult to obtain fluidity at room temperature, and if it exceeds 17 wt%, the strength of the construction body is reduced. For example, using a JIS R-2521 flow tester, the cone is filled with the material, the cone is removed, and the mixture is added so that the value naturally flows for 1 minute to 120 mm or more.

When the refractory aggregate is coated with the oily liquid silicone resin, it is more effective to target only the coarse grains or the coarse grains and the medium grains among the refractory aggregates. This is because the raw material settled by the solid-liquid separation is a coarse-grained portion or a medium-grained portion having a high density, and it is not necessary to treat the fine-grained portion. This is because the liquidity tends to decrease.

The amount of the oily liquid silicone resin added is 0.05 wt% as an external weight to 100 wt% of the refractory aggregate.
If it is less than the above, the effect of suppressing solid-liquid separation is small. If the amount exceeds 5% by weight, the effect does not change, but the cost of the oily liquid silicone resin is high, so that the amount added increases the cost, which is not preferable.

Although the specific type of paper fiber is not limited, crushed paper, beaten paper and the like are used. The amount of addition is 0.01 to 2 wt.
%. Addition of less than 0.01% has no thickening effect. Addition of more than 2 wt% has an excessively thickening effect, and further increases the porosity of the construction body.

[0025]

EXAMPLES Table 1 shows the compounding compositions of the examples of the present invention and their comparative examples.

Examples 1 to 3 of the present invention and Comparative Examples 1 and 2
Was tested by batch kneading each formulation. Example 4 of the present invention
9 to 9 and Comparative Examples 3 and 4, for the refractory aggregate marked with *, the surface was coated with the oily liquid silicone resin by previously mixing the refractory aggregate with the oily liquid silicone resin, and other fire resistance An aggregate, a phenol resin, and a solvent are added and kneaded.

The novolac type phenolic resin in Example 4 and the resol type phenolic resin in Example 7 were used in solid form. The phenol resin in each of the other examples was prepared by dissolving it in a solvent in advance.

Table 2 shows the test results of each example. The test method is as follows.

Solid-liquid separation: A container containing 2 kg of a sample is placed at 35 ° C.
In an atmosphere, after applying a vibration force of 4 G for 1 hour, a gold rod having a diameter of 10 mm and a weight of 400 g is immersed in the repair material in the container to remove coarse particles and medium particles formed in the repair material at the bottom of the container. By measuring the position of the hard layer made of aggregate,
The thickness of the sedimentation layer was determined.

Change with time: 1 immediately after production and under 35 ° C. atmosphere
The free flow value after storage for 0 days was measured to determine the change with time in workability.

Thermal fluidity: 200 g of the sample was placed on a brick heated to 1000 ° C. in a vinyl bag having a diameter of 50 mm and allowed to stand still, and the spread and height after thermal fluidization were measured. The one with a large spread value and the one with a low height have excellent heat fluidity.

Curing time: A tin can containing 250 g of the sample was placed in a furnace under an atmosphere of 350 ° C., and the can was taken out of the furnace every 5 minutes, and the degree of curing of the sample was examined. The time when the sample stopped flowing out of the can with the can turned upside down was defined as the curing time.

Actual machine test: In a hot repair of a 250 t converter, especially a charging wall, a polypropylene bag was put into a repaired part through a chute and tested for heat fluidity and durability. The temperature of the surface to be repaired is 1000-
It was 1200 ° C. The blanks are those not tested.

As can be seen from the test results shown in Table 2, in all the examples of the present invention, the thickness of the sedimentation layer was small and the change with time was small.
Moreover, because of its excellent heat fluidity, even in the actual machine test, about twice the durability was obtained as compared with Comparative Examples 1 and 2 corresponding to the conventional products. In addition, among the examples of the present invention, those using the refractory aggregate coated with the liquid silicone resin,
Further improved in durability.

On the other hand, in Comparative Examples 1 and 2 which did not use the oily liquid silicone resin, the thickness of the sedimentation layer was remarkably large, and the results of aging and thermal fluidity were poor. Although the test result of Comparative Example 3 in which the oily liquid silicone resin is excessively added is not different from that of the example of the present invention, the cost of the oily liquid silicone resin is high, and therefore the cost is increased, which is not preferable.

The examples of the present invention in which paper fibers were added showed a remarkable effect in the solid-liquid separation test. No change over time,
It does not hinder the heat fluidity. However, as shown in Comparative Example 4, when added in a large amount, the fluidity at room temperature is lowered and the filling property is deteriorated.

Regarding the curing time, the examples of the present invention in which the paper fiber is added are earlier, and it is considered that the acceleration of deaeration of the solvent or the like accelerates the curing. Further, compared with the examples of the present invention using only the novolac type phenol resin, the examples 6, 7, and 9 of the present invention using the resol type phenol resin are shorter, and the workability and workability due to the shortening of the repair time are excellent.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Effect] As described above, the bake repair material according to the present invention is excellent in that it exhibits good heat fluidity by suppressing the sedimentation of the refractory aggregate and can reliably fill the repaired part. The repair effect can be obtained. Moreover, the suppression of settling of the refractory aggregate has an effect of preventing a change over time, and stable workability can be obtained even during long-term storage.

Furthermore, the addition of paper fibers is effective in preventing vibration during transportation due to the thickening effect of the liquid, and the effect of accelerating degassing of the liquid helps accelerate the hardening of the baking repair material.

Further, when the refractory aggregate is coated with the oily liquid silicone resin, a more excellent effect is exhibited in preventing the change over time.

Further, the curing time was shortened and the repair efficiency was improved by the combined addition of the resol type phenol resin as the binder.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Taizo Taehiro 1-3-1, Niihama, Arai-cho, Takasago-shi, Hyogo Harima Ceramic Co., Ltd. (72) Kozo Yamada 1-3-1 Niihama, Arai-cho, Takasago-shi, Hyogo No. within Harima Ceramic Co., Ltd.

Claims (4)

[Claims] 1. A novolak type phenolic resin of 7 to 17 wt%, a solvent of 7 to 17 wt% and an oily liquid silicone resin of 0.05 wt% with respect to 100 wt% of a refractory aggregate.
Bake repair material containing ~ 5wt%. 2. A novolak type phenolic resin of 7 to 17 wt%, a solvent of 7 to 17 wt% and an oily liquid silicone resin of 0.05 wt% with respect to 100 wt% of a refractory aggregate.
A baking repair material containing ˜5 wt% and paper fiber 0.01-2 wt%. 3. The baking repair material according to claim 1, wherein the refractory aggregate is coated with an oily liquid silicone resin. 4. The baking repair material according to claim 1, which comprises 100 wt% of the refractory aggregate and 5 wt% or less of a resole-type phenol resin when applied outside.