JP2002274961A - Binder composition for refractory material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder composition which can prevent solidification or separation of a refractory material with an indeterminated form and improves fluidity of the irregular refractory material in a hot process. SOLUTION: The binder composition for a refractory material contains a novolac phenol resin and acetoacetanilide as the essential components by 95/5 to 50/50 compounding ratio by weight of the novolac phenol resin to acetoacetanilide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder composition for a refractory, and more particularly to a binder composition for an amorphous refractory, which can prevent solidification and separation of the refractory and improve the fluidity of the amorphous refractory when hot. A binder composition to be made.

[0002]

2. Description of the Prior Art Graphite-containing unfired bricks using a phenolic resin as a binder are used in converters, electric furnaces, ladles and the like. Along with this, it is also possible to use graphite, magnesia, alumina and other aggregates containing a phenolic resin as a binder, as well as amorphous refractories used mainly for repairing furnace walls and furnace bottoms of the above steelmaking facilities. Many. A baking material is one of the irregular shaped refractories for repairing the furnace bottom and the like. When a phenol resin is used for the baking material, it is common to use a novolak-type phenol resin having good fluidity in hot water. In this case, a binder obtained by using a solid or powdered novolak phenol resin in combination with a wetting agent such as a polyhydric alcohol, or by dissolving a novolak phenol in a polyhydric alcohol in advance is used as the binder.

[0003] However, in the case of irregular-shaped refractories used for repair, there are cases where it takes more than three months from the time when the binder with various aggregates is kneaded to the time when it is used. In such a case, if the above-mentioned conventional binder is used, the amorphous refractory may solidify during storage, or the aggregate and the binder may be separated and cannot be used. When a solid or powdery novolak type phenol resin is used alone, there is no problem of caking and separation, but sufficient fluidity and adhesiveness during hot due to carbonization shrinkage of the phenol resin, etc. I can't get it.

[0004]

The inventors of the present invention have made intensive studies to overcome these drawbacks. As a result, by adding acetoacetanilide as a fluidizing agent to a novolak-type phenol resin, the storage stability at room temperature is excellent. Further, the present inventors have found that fluidity during hot operation is improved and good adhesiveness can be obtained, and the present invention has been accomplished.

[0005]

The present invention contains a novolak type phenol resin and acetoacetanilide as essential components, and the compounding ratio of the novolak type phenol resin and acetoacetanilide is 95/5 to 50/50 by weight. A binder composition for refractories.

The novolak type phenol resin used in the present invention is generally prepared by converting an acid substance such as oxalic acid, hydrochloric acid, sulfuric acid or the like or a metal salt of an organic acid into a phenol and an aldehyde in a molar ratio of aldehyde to phenol of 0.3 to 0.3.
The reaction was carried out at 1.0. Phenols used as raw materials for novolak type phenol resins include phenol, cresol, xylenol, paratertiary butylphenol, paraoctylphenol, paranonylphenol, paracumylphenol and bisphenol A. These are used alone or in combination of two or more. it can. Phenol and cresol are preferred for reasons such as cost and carbonization rate of the resin. On the other hand, as aldehydes, formalin is usually used, but aldehyde-generating substances such as paraformaldehyde and trioxane, and benzaldehyde can also be used.

The acetoacetanilide used in the present invention is
It is a substance having a molecular weight of 177.21 and a melting point of 82.5 ° C, and is solid at ordinary temperature. Therefore, even if a suitable amount is blended with the novolak type phenol resin, the blended composition is solid, and there is no fear of solidification and separation of the amorphous refractory even when this is used as a binder.
In addition, since acetoacetanilide has a low viscosity when melted, the fluidity of the amorphous refractory during heating is improved.

5-50 / 50, preferably 90/10
60/40. If the amount of acetoacetanilide is larger than this, the melting point of the binder composition may decrease, depending on the melting point of the novolak-type phenolic resin, and the binder composition may not be solid or powdery. In addition, the fixed carbon ratio becomes low, and sufficient strength may not be obtained after construction. On the other hand, if the compounding amount is smaller than this, the effect of improving the fluidity during heating of the amorphous refractory is small, and sufficient repair cannot be performed.

The binder composition used in the present invention is solid,
Any powder may be used, but in consideration of dispersion into irregular-shaped refractories, powder is preferable, and a smaller particle size is more preferable. As a method of mixing the novolak type phenol resin and acetoacetanilide, there are methods such as pulverization and mixing, mixing with a pressure kneader, and melt mixing. Melt mixing is desirable in consideration of the dispersibility of acetoacetanilide.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments. However, the present invention is not limited to the embodiments. Further, “parts” and “%” described below all indicate “parts by weight” and “% by weight”. The melting point was evaluated by the following method. Melting point measuring method: A sample is made into a fine powder, which is put in a capillary tube, and the thickness of the resin layer is 2-3.
mm. The temperature of the capillary filled with the sample is raised at 1.5 ° C. in the solution. The sample is visually observed, and the temperature at which the sample liquefies in the capillary and no solid is observed is defined as the melting point.

Example 1 A reactor equipped with a stirrer, a reflux condenser and a thermometer was charged with 100 parts of phenol, 70 parts of 37% formalin and 1 part of oxalic acid, and reacted under reflux conditions for 3 hours. Next, dehydration and dephenolation were performed under reduced pressure until the amount of free phenol reached a predetermined value, and then taken out to obtain 103 g of a solid novolak-type phenol resin A. This resin had a melting point of 90 ° C. and free phenol of 3.0%. Next, 90 parts of the novolak type phenolic resin A and 10 parts of acetoacetanilide were melt-mixed and then taken out and pulverized to obtain a powdery binder composition B. Composition B had a melting point of 70 ° C. and 2.7% of free phenol.

Example 2 70 parts of the solid novolak type phenolic resin A prepared in Example 1 and 30 parts of acetoacetanilide were melt-mixed and then taken out and pulverized to obtain a powdery binder composition C.
Composition C had a melting point of 50 ° C. and 2.1% free phenol.

Comparative Example 1 Only the solid novolak type phenolic resin A produced in Example 1 was pulverized to obtain a powdery binder A.

Comparative Example 2 97 parts of the solid novolak type phenolic resin A prepared in Example 1 and 3 parts of acetoacetanilide were melt-mixed, taken out and pulverized to obtain a powdery binder composition D. Composition D had a melting point of 80 ° C. and 2.9% free phenol.

Comparative Example 3 40 parts of the solid novolak type phenolic resin A prepared in Example 1 and 60 parts of acetoacetanilide were melt-mixed and then taken out, but the melting point was too low to be powdered. Handling was difficult, and the properties as a refractory binder could not be evaluated.

<Practical test> 400 parts of fine magnesia clinker (particle diameter: 0.3 to 1 mm), 600 parts of magnesia clinker fine powder (particle diameter: 0.1 mm or less), and 200 parts of the above binder or binder composition are sufficiently used. To obtain an amorphous refractory. Next, 100 g of the irregular-shaped refractory is wrapped in a vinyl sheet, and 200 mm in an electric furnace having an internal temperature of 1000 ° C.
It was dropped on a ceramic plate of × 200 mm × 10 mm, left to stand until the fluidity disappeared, and the diameter of the expanded amorphous refractory was measured. At this time, the adhesion between the ceramic plate and the hardened refractory was observed. Table 1 shows the results.

[0017]

[Table 1]

As is evident from Table 1, Comparative Example 1 did not contain acetoacetanilide, and thus had poor hot fluidity. In addition, the carbonization shrinkage was large and did not adhere well to the ceramic plate. Comparative Example 2 is a case where the blending amount of acetoacetanilide is small, but the fluidity in hot is not improved, the carbonization shrinkage is large, and the adhesion to the ceramic plate is not improved. Comparative Example 2 is a case where the amount of acetoacetanilide is too large, but the melting point is too low to make a solid or powder.
For this reason, the characteristics as a refractory binder could not be evaluated. In contrast, Example 1 and Example 2
It was powdery at room temperature, had a long flow distance during hot and was good, and had good adhesion to a ceramic plate.

[0019]

The use of the refractory binder composition of the present invention in which an appropriate amount of acetoacetanilide is blended with a novolak-type phenol resin can prevent solidification and separation of the amorphous refractory, and can prevent the refractory from becoming hot. An amorphous refractory with good fluidity and adhesion can be obtained.

Claims (1)

[Claims] 1. A refractory material comprising a novolak-type phenol resin and acetoacetanilide as essential components, and a compounding ratio of the novolak-type phenol resin and acetoacetanilide in a weight ratio of 95/5 to 50/50. Binder composition.