JPH09132467A - Fixed shaped joint filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart moldability and thermoplasticity to a fixed shape joint filler formed by coating least one surface of sheet-like refractories having plasticity with a rigid and thermally softenable plate and to impart a low fuming property and a characteristic to obviate the occurrence of a change with lapse of time in this characteristic to this filler. SOLUTION: This joint filler is obtd. by molding the kneaded matter obtd. by adding a polybutene emulsion at 15 to 40wt.% in outer per cent as a binder to 100wt.% raw material powder which is fixed shape joint stock. Since the polybutene is used by emulsifying the polybutene in water, an advantage lies in that the fuming is lessened when the material is set as the joint filler in a nozzle, etc. Namely, the moinsture evaporates first with an increase in the temp. of the joint filler when the joint filler is mounted at the immersion nozzle preheated to 600 to 1,000 deg.C and, therefore, the temp. elevation of the joint filler itself is suppressed. The combustion of the org. matter is consequently suppressed and the fuming is lessened. The polybutene consists of C and H as its molecular structure and does not contain active OH groups and COOR groups (R: alkyl group) and, therefore, there is no reaction with the refractor raw material powder and the change with lapse of time is hardly admitted.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a joint material applied to a joint surface of a refractory material.

[0002]

2. Description of the Related Art Joint materials such as refractory mortar, ceramic fibers, and sheet-shaped refractories have been conventionally used for joining surfaces between refractories such as nozzles used for continuous casting of molten steel.

Among them, the standard joint material composed of a sheet-shaped refractory material is a sheet made of a plastic refractory material which is processed in advance into a shape close to the shape of the joint, and has a higher shape than mortar. It has been widely used because of its advantages such as having a sealing property, no variation in thickness, and easy handling.

However, in recent years, from the viewpoint of safety and working environment in steelmaking, automation of handling of refractory materials is being promoted, and such soft sheet-shaped standard joint material is held by an automatic machine. There is a problem that it is difficult. In order to solve this problem, Japanese Patent Laid-Open No. 5-94245
In the publication, it is proposed that both sides or one side of a sheet-shaped refractory material be sandwiched between hard heat-softening plates.

On the other hand, this sheet-shaped refractory material is required to have ductility so that the joint material is sufficiently extended under pressure. Conventionally, the addition of phenolic resin, vinyl acetate emulsion, rubber lattice, etc. as a binder has been disclosed in Japanese Patent Publication No. 60-15592 and Japanese Patent Publication No. 7-118073. However, when using a phenol resin as a binder,
Smoke is generated hot and the working environment is deteriorated.In addition, when vinyl acetate emulsion or rubber lattice is added, a hard surface film is formed over time and cracks occur due to bending during handling. There is a problem that it will not fulfill its function as.

[0006]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to form a joint material having a hard heat-softenable plate on at least one side of a sheet-like refractory material having plasticity, and to obtain moldability and hot spreading. The purpose is to impart ductility, low smoke generation properties, and properties that do not change over time.

[0007]

According to the present invention, 100% by weight of a raw material powder, which is a standard joint material, is added to a polybutene emulsion as a binder in an amount of 15 to 40% by weight to obtain a kneaded product. I solved the problem.

The amount of polybutene emulsion added is 15 to
40% by weight is preferable, and if it is less than 15% by weight, the kneaded product becomes hard and there is a problem that cracks occur when it is made into a thin sheet-shaped molded product. If it is more than 40% by weight, the kneaded product becomes too soft. There is a problem that a sheet-shaped molded product cannot be obtained.

The polybutene emulsion is obtained by emulsifying polybutene with water using a surfactant, and its concentration is preferably 20 to 80% by weight. If the amount is less than 20% by weight, the molded article has a large change over time, and if the amount is more than 80% by weight, there is a problem that smoking during use is severe.

Since polybutene is used by emulsifying it in water,
When it is set as a joint material in a nozzle or the like, there is an advantage that smoke is not reduced. That is, for example,
When attached to a preheated dipping nozzle of 0 to 1000 ° C, the temperature rise of the joint material itself is suppressed because the water content first evaporates as the joint material temperature rises, so that the combustion of organic matter is suppressed and smoke is reduced. Become.

Polybutene has a molecular structure of C and H.
Since there is no active OH group or COOR group (R: alkyl group), there is no reaction with the refractory raw material powder and almost no change with time is observed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The raw material powder of the present invention uses, as a main raw material, one or more of alumina, silica, zirconia, magnesia, mullite, chromium oxide, calcia, silicon carbide, silicon nitride, graphite and the like. It is possible.

Clay, frit, metal, and fibrous material are added to the main raw material as auxiliary raw materials. Clay is used to provide plasticity. The frit is added for the purpose of assisting plasticity during hot and for improving the sinterability, and it is preferable that the frit has a melting point of 300 to 1200 ° C. The metal is added for the purpose of preventing oxidation, assisting hot plasticity, and expanding hot, and may be, for example, one or more of Al, Mg, Si and the like, or alloys thereof. The fibers are used for the purpose of preventing cracks and the like, and inorganic fibers are preferable.

Although the particle size of the raw material powder varies depending on the site to be used, it is preferably 0.5 mm or less from the viewpoint of plasticity. The blending ratio is 20 to 97% by weight of the main raw material and 1 to 30% by weight as the auxiliary raw material. When the main raw material is less than 20% by weight, there is a problem that the heat resistance is lowered, and when it is more than 97% by weight, the elongation of the material is deteriorated. Secondary material is 1% by weight
If it is less, the elongation is poor, and if it is more than 30% by weight, the corrosion resistance decreases.

[0015]

EXAMPLES The present invention will be described by way of an example in which the ladle is applied to a standard joint material for an upper nozzle refractory of a ladle.

Polybutene emulsion as a binder was added to 100% by weight of the refractory raw material powder having the compounding ratio (% by weight) shown in Table 1 in a weight ratio as shown in Table 2 and kneaded by using a bench mixer. did. A commercially available product was used as the polybutene emulsion. At this time, the kneaded product had a consistency adjusted to 60 to 80 when measured with a consistency meter by adjusting the addition amount of the polybutene emulsion.

After kneading with a desk mixer for 15 minutes, it was pressed with an Amsler and molded to obtain a sheet-like refractory 1 having a thickness of 5 mm as shown in FIG. 1, which was further cut into a fan shape and a rectangle to obtain a raw material powder. Sheet refractory molded bodies 2a and 2b made of the kneaded product of were obtained. Then, as shown in FIG. 2, the sheet refractory molded bodies 2a and 2b are formed to a thickness of 0.5.
mm of the frustoconical heat-softening plate was coated on the polystyrene sheet 3, and further, a frustoconical heat-softening plate of the plastic sheet was also coated thereon. As a result, as shown in the sectional structure of FIG. 3, a fixed joint material 4 for the upper nozzle was obtained in which the front and back of the sheet refractory molded bodies 3a and 3b were covered with the plastic sheet 2.

The moldability, smoke emission, and changes with time of the properties of the standard joint material for nozzles obtained from the respective compounding compositions shown in Table 2 were examined. The moldability was evaluated as good or bad by observing the state of cracks generated during the molding process and checking the presence or absence of cracks. The smoke emission property was classified into good and bad depending on the presence or absence of smoke generation for 30 seconds after the molded body was set in the nozzle heated to 800 ° C in an electric furnace. Regarding the change with time, the molded product of FIG. 1 was allowed to stand at room temperature for 3 months, and the consistency was measured with a consistency meter. If the value was 30 to 80, it was evaluated as good, and the others were evaluated as bad. Table 2 shows the evaluation results.
Shown in From Table 2, it is apparent that Examples 1 to 6 have no change over time, smoke generation is reduced, and workability is excellent as compared with Comparative Examples.

[0019]

[Table 1]

[Table 2]

[0020]

The use of polybutene emulsion as the binder has the following effects.

(1) On-site smoke generation during hot set is reduced.

(2) Even if the sheet is formed into the joint shape of the nozzle, cracks are not generated.

(3) Good plasticity can be obtained without aging even after 3 months.

(4) The workability at the time of setting is improved and a uniform joint thickness can be maintained.

[Brief description of the drawings]

FIG. 1 shows a molding process of a sheet refractory for obtaining a standard joint material for an upper nozzle.

FIG. 2 shows a coating process of a plastic sheet on a sheet refractory body.

FIG. 3 shows a cross-sectional structure of the obtained standard joint material for the upper nozzle.

[Explanation of symbols]

 1 Sheet-like refractory 2a, 2b Sheet refractory molded body 3 Thermal softening plate 4 Regular joint material for upper nozzle

Claims (1)

[Claims] 1. A standard joint material in which at least one surface of a plastic sheet-like refractory is coated with a hard heat-softening plate, wherein the sheet-like refractory is 100% by weight of the raw material powder.
Externally using polybutene emulsion as a binder 15 ~
A standard joint material formed by molding a kneaded product containing 40% by weight.