JP2006089545A - Binder composition for monolithic refractory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a binder composition for monolithic refractory good in curability at room temperature. <P>SOLUTION: The binder composition for monolithic refractory comprises a combination of sodium phosphate with a phenolic resin, wherein the phenolic resin contains an alkylbenzene-modified phenol. Preferably, the phenolic resin consists of a novolak-type phenolic resin and a resol-type phenolic resin with the compounding ratio of the novolak-type phenolic resin to resol-type phenolic resin being (95:5) to (50:50) and the modification percentage of the alkylbenzene in the phenolic resin is 30-80 wt.%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a binder composition for amorphous refractories.

  In recent years, in steelmaking facilities such as converters, electric furnaces, ladles, etc., the amount of non-fired bricks containing graphite using a phenol resin as a binder is increasing. Along with this, a case of using an amorphous refractory (spraying material) used for repairing the furnace wall and bottom of a steelmaking facility, which is a mixture of graphite, magnesia, alumina or other aggregate with a phenolic resin as a binder. Is increasing.

For example, when a powdered novolac type phenol resin containing hexamethylenetetramine is used alone as a binder for this spraying material, a large amount of volatile matter is generated due to the decomposition of hexamethylenetetramine at the time of curing, which is sufficient as a repairing material. May not provide sufficient strength.
Moreover, when a powder resol type phenol resin is used independently, since molecular weight is generally smaller than a novolak type phenol resin, there are many volatile components in resin, and this may foam. When sprayed on a heated wall surface, the wall surface may be sagged before being cured by adhering to the wall surface. In either case, there is a problem that sufficient repair performance cannot be obtained.

As a means for solving this, a method of using a binder composition having a blending ratio of novolak type phenolic resin and resol type phenolic resin of 95/5 to 50/50 as a binder has been put into practical use (for example, patents). Reference 1).
However, since phenolic resin is a thermosetting resin, when phenolic resin is used as a binder, heating is required to cure any of them, and curing at room temperature is virtually impossible.

On the other hand, sodium phosphate, which can be strongly bonded to aggregates such as magnesia and alumina, and can be cured at room temperature by using an appropriate curing agent such as calcium hydroxide, is used as a binder. Are also used (see, for example, Patent Document 2).
However, the spray material using sodium phosphate salt as a binder exhibits strength when fired at about 1000 ° C. or higher, but the strength rapidly increases at 500 to 900 ° C., which is an intermediate temperature range between the room temperature and the firing temperature. There is a problem that sufficient repair performance cannot be obtained.

A spraying material that uses both phenolic resin and sodium phosphate salt as a supplement to both the problems when using phenolic resin as a binder and the problems when using sodium phosphate salt as a binder. Is being considered.
However, when sodium phosphate and a phenol resin are used in combination, the phenolic hydroxyl group of the phenol resin reacts with a divalent metal salt that is a curing agent for the sodium phosphate, so that the sodium phosphate is sufficiently room temperature. There was a problem that it could not be cured.

Japanese Patent Laid-Open No. 11-035792 JP-A-6-56539

  The present invention has been made as a result of studies to solve the problems of conventional binders for irregular refractories. When sodium phosphate and a phenol resin are used in combination as a binder, the room temperature of sodium phosphate is The present invention provides a binder composition for an amorphous refractory that has good curability at room temperature without inhibiting curing and can impart sufficient strength by firing.

Such an object is achieved by the following present inventions (1) to (8).
(1) A binder composition used for an amorphous refractory, comprising a sodium phosphate salt, a divalent metal salt, and a phenol resin, wherein the phenol resin contains an alkylbenzene-modified phenol resin. A binder composition for amorphous refractories.
(2) The said phenol resin is a binder composition for amorphous refractories as described in said (1) whose modification | denaturation rate by the alkylbenzene with respect to the said phenol resin whole is 30 to 80 weight%.
(3) The binder composition for an amorphous refractory according to (1) or (2), wherein the phenol resin contains a novolac type phenol resin and a resol type phenol resin.
(4) The weight ratio of the novolac type phenol resin and the resol type phenol resin is novolak type phenol resin / resole type phenol resin = 95/5 or more and 50/50 or less. Binder composition for physical use.
(5) The binder composition for an amorphous refractory according to any one of the above (1) to (4), wherein the alkylbenzene-modified phenol resin includes a product obtained by reacting an alkylbenzene resin with phenols.
(6) The alkylbenzene-modified phenolic resin according to any one of (1) to (5) above, which includes a product obtained by reacting an alkylbenzene resin with a phenol and further reacting with an aldehyde. A binder composition for amorphous refractories.
(7) The above-mentioned alkylbenzene resin includes a bond obtained by reacting at least one selected from toluene, xylene, and mesitylene with formaldehyde, and the bond for amorphous refractory according to (5) or (6) above Agent composition.
(8) The weight blending ratio of the sodium phosphate sodium salt and the phenol resin is sodium phosphate salt / phenol resin = 10/2 or more and 10/8 or less, according to any one of the above (1) to (7). A binder composition for amorphous refractories.

  The binder composition for amorphous refractory according to the present invention has good curability at room temperature and can impart sufficient strength by firing, so that the amorphous refractory has good repair performance at room temperature. It is preferably used as a binder for an application.

Below, the binder composition for amorphous refractories of this invention is demonstrated.
The binder composition for an amorphous refractory of the present invention (hereinafter sometimes simply referred to as “composition”) contains a sodium phosphate salt, a divalent metal salt, and a phenol resin. An alkylbenzene-modified phenol resin is included.

  Although the sodium phosphate salt mix | blended with the composition of this invention is not specifically limited, For example, condensed sodium phosphate, acidic sodium pyrophosphate, sodium tripolyphosphate, sodium tetrapolyphosphate, sodium pentapolyphosphate, sodium hexapolyphosphate , Sodium hexametaphosphate, sodium metaphosphate and the like.

  As a phenol resin mix | blended with the composition of this invention, a novolak type phenol resin and a resol type phenol resin are mentioned. These novolak-type phenol resins (hereinafter sometimes simply referred to as “novolak resins”) and resol-type phenol resins (hereinafter sometimes simply referred to as “resole resins”) are obtained by polycondensation of phenols and aldehydes. It is obtained.

  Although it does not specifically limit as phenol here, For example, phenol, o-cresol, m-cresol, p-cresol, xylenol, p-tertiary butylphenol, p-octylphenol, p-nonylphenol, p-cumylphenol, Although other alkylphenols are mentioned, these may be used alone or in admixture of two or more. Among these, for amorphous refractories, phenol and cresol are preferred because a higher carbonization rate tends to provide higher strength after firing.

  The aldehydes are not particularly limited, and examples thereof include formaldehyde, paraformaldehyde, benzaldehyde and the like, substances that generate these aldehydes, and solutions of these aldehydes. Two or more kinds may be mixed and used. Of these, formaldehyde and paraformaldehyde are usually preferred for use in amorphous refractories because of their high reactivity during phenol resin synthesis.

The novolak resin used in the composition of the present invention can be obtained by reacting the phenols and aldehydes in the presence of an acidic catalyst.
Although it does not specifically limit as this acidic catalyst, For example, organic acids, such as inorganic acids, such as a sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, or para-toluenesulfonic acid, benzenesulfonic acid, oxalic acid, maleic acid, formic acid, acetic acid, oxalic acid Is mentioned.
This novolak resin is usually charged with phenols (P ₁ ) and aldehydes (F ₁ ) at a molar ratio (F ₁ / P ₁ ) = 0.3 or more and 1.0 or less, and using the above acidic catalyst. It can be produced by condensation and dehydration by a conventional method.

The resol resin used in the composition of the present invention can be obtained by reacting the above phenols and aldehydes in the presence of an alkaline catalyst.
The alkaline catalyst is not particularly limited, and examples thereof include metal salts such as zinc acetate, alkalis such as sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide, and amines such as ammonia and triethylamine.
This resol resin usually comprises phenols (P ₂ ) and aldehydes (F ₂ ) in a molar ratio (F ₂ / P ₂ ) = 1.0 or more and 3.0 or less (in some cases less than 1.0 or And may be produced by condensation and dehydration using the above alkaline catalyst by a conventional method.

  The phenol resin used in the composition of the present invention is characterized by containing an alkylbenzene-modified phenol resin.

The alkylbenzene-modified phenol resin used in the composition of the present invention is one in which alkylbenzene is bonded to phenols by a methylene bond or the like.
The method for producing the alkylbenzene-modified phenolic resin is not particularly limited. This can be produced by reacting with phenols in the presence of an acidic catalyst.
Moreover, what was obtained above can be made to react with aldehydes further. Thereby, the resin obtained can be made high molecular weight.

  When a resol-type alkylbenzene-modified phenol resin is obtained, it can be produced, for example, by synthesizing the novolac-type alkylbenzene-modified phenol resin and then adding an alkaline catalyst to react with formaldehyde. This production method is preferable because an alkylbenzene-modified phenol resin can be efficiently obtained without revealing a difference in reactivity between alkylbenzene and phenols.

Although it does not specifically limit as alkylbenzene used for manufacture of the said alkylbenzene resin, Usually, a methyl group or an ethyl group is preferable as an alkyl group, and what couple | bonded this to the benzene ring 1-3 is used.
Among these, an alkylbenzene resin obtained by using one or more selected from toluene, xylene, and mesitylene as the alkylbenzene and reacting it with formaldehyde in the presence of an acidic catalyst such as sulfuric acid is preferable. Examples of these include xylene resins obtained by reacting xylene and formaldehyde, mesitylene resins obtained by reacting mesitylene and formaldehyde, and the like. These alkylbenzene resins have a methylol group, a dimethylene ether group, an acetal group or the like as a benzene nucleus-bonding functional group, and have good reactivity with phenols. The properties are usually a viscous liquid and are easy to handle.

  In addition, as alkylbenzene resin, you may synthesize | combine by the said reaction method and may use the commercial item prepared by the target property. Examples of commercially available products that can be used in the production of the alkylbenzene-modified phenolic resin used in the present invention include “Nicanol H” manufactured by Mitsubishi Gas Chemical Co., Ltd. as a xylene resin and “Nicanol M” as a mesitylene resin.

The rate of modification of the alkylbenzene-modified phenol resin used in the composition of the present invention with alkylbenzene is not particularly limited, but is preferably 30% by weight or more and 80% by weight or less. The modification rate referred to here is the ratio of the alkylbenzene resin used in the production of the alkylbenzene-modified phenolic resin to the entire phenolic resin, calculated by weight%.
When the modification rate exceeds the above upper limit, the curability of the phenol resin is lowered, and the strength of the amorphous refractory may be lowered. On the other hand, if it is less than the lower limit, the effect of ensuring room temperature curing of the sodium phosphate salt may not be sufficiently obtained.

  In the composition of the present invention, the novolak resin or the resole resin can be used alone, but it is preferable to use the novolac resin and the resole resin in combination. As a result, compared with the case where novolac resin is used alone with hexamethylenetetramine as a curing agent, or when resole resin is used alone, the generation of volatile matter is reduced, and foaming is suppressed and the amorphous refractory is suppressed. The strength of can be improved.

In the composition of the present invention, when the novolak resin and the resole resin are used in combination, the blending weight ratio is not particularly limited, but it is preferably novolak resin / resole resin = 95/5 or more and 50/50 or less. More preferably, it is 90/10 or more and 60/40 or less. Thereby, when a composition is hardened, favorable intensity | strength can be obtained and adhesiveness can be improved.
If the ratio of the resole resin is less than the above lower limit value, sufficient strength may not be obtained. If the ratio of the resole resin exceeds the above upper limit, the molecular weight of the entire composition becomes small, and after heating it adheres to the wall surface such as a vertical surface or an inclined surface, it will sag from the wall surface before the phenol resin is cured. In some cases, the hot adhesion may decrease. Moreover, the volatile component at the time of resin hardening increases, and sufficient intensity | strength may not be obtained by foaming.

In the composition of the present invention, the form using the alkylbenzene-modified phenol resin is not particularly limited. For example, when a novolak resin is used alone as the phenol resin, the alkylbenzene-modified phenol resin is used as the novolak resin, and the resole resin is used. When is used alone, an alkylbenzene-modified phenol resin can be used as the resol resin.
When a novolac resin and a resole resin are used in combination as the phenol resin, an alkylbenzene-modified phenol resin can be used for either or both of the novolac resin and the resole resin.

  The form of the phenol resin used in the composition of the present invention is not particularly limited, but it is desirable to pulverize the phenol resin, or to pulverize and mix these when using two or more types of phenol resins, and use them in powder form. . When the phenol resin is in a liquid state, since the amount of volatile components in the resin is large, a sufficient binder effect may not be obtained depending on the composition and curing conditions of the composition.

A divalent metal salt is used in the composition of the present invention. Thereby, a sodium phosphate sodium salt can be hardened. The divalent metal salt used in the present invention is not particularly limited, and examples thereof include calcium aluminate and calcium hydroxide. Among these, calcium hydroxide is preferable from the viewpoint of price.
The blending amount of the divalent metal salt can be appropriately set according to the blending amount of the sodium phosphate salt, but is usually in the range of 50 to 150 parts by weight with respect to 100 parts by weight of the sodium phosphate salt. Can be used.

  In the composition of the present invention, the mechanism by which the room temperature curability of the sodium phosphate salt can be improved by using an alkylbenzene-modified phenol resin is not clear, but is considered as follows.

  First, the curing reaction of sodium phosphate salt. For example, when calcium hydroxide is used as a curing agent, calcium ions cause a substitution reaction with sodium in sodium phosphate salt, and are represented by the following chemical reaction formula (1). It is considered that the curing reaction proceeds as shown.

  When a phenol resin is contained in this reaction system, calcium ions not only react with sodium phosphate, but also react with phenolic hydroxyl groups in the phenol resin. Thereby, it is considered that the crosslinking of the sodium phosphate salt does not proceed sufficiently and the curing is insufficient. This is shown in chemical reaction formula (2) below.

The composition of the present invention is characterized in that an alkylbenzene-modified phenol resin is used as a phenol resin in a form in which a sodium phosphate salt and a phenol resin are used in combination.
The alkylbenzene-modified phenol resin has a lower ratio of phenolic hydroxyl groups in the phenol resin than the unmodified phenol resin. As a result, the reaction between the phenolic resin and the divalent metal ion can be suppressed, so that crosslinking can be promoted by the reaction between the sodium phosphate salt and the divalent metal ion, and sufficient curability can be ensured even at room temperature. .
Furthermore, the sodium phosphate salt cured at room temperature can be baked by raising the temperature to about 1000 ° C. or higher to develop sufficient strength, but in the composition of the present invention, the temperature rises to the above temperature. Since the phenol resin is cured during the heating process, strength can be imparted by this, so that the strength reduction is significant when the process up to the firing temperature, that is, when a conventional sodium phosphate salt is used alone. Even in the temperature range of about 500 to 900 ° C., the repaired portion does not cause a decrease in strength, and good repair performance can be ensured.

In the composition of the present invention, the mixing ratio of the sodium phosphate salt and the phenol resin is not particularly limited, but is preferably 10/2 or more and 10/8 or less. More preferably, it is 10/3 or more and 10/6 or less.
Thereby, sufficient room temperature curability can be provided. When the blending ratio of the sodium phosphate salt is less than the above lower limit, curing at room temperature may be insufficient. On the other hand, if the upper limit is exceeded, the strength of the repaired part after firing may be reduced.

  When the composition of the present invention is used as a binder for an amorphous refractory, a usual method can be applied. That is, an amorphous refractory can be obtained by kneading a refractory aggregate such as alumina, magnesia, and scaly graphite with the composition of the present invention in a predetermined composition.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples. “Parts” described herein all represent “parts by weight”, and “%” all represent “% by weight”.

1. Production of novolak resin <Production Example 1>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol and 600 parts of xylene resin ("Nikanol H" manufactured by Mitsubishi Gas Chemical Co., Ltd.), 5 parts of oxalic acid was added, and the reaction was carried out at 97-103 ° C for 3 hours. . Thereafter, 5 parts of oxalic acid and 350 parts of 37% formalin were gradually added, and the reaction was carried out at 97-103 ° C. for 2 hours. Then, after dehydrating and dephenoling under reduced pressure until the desired water content and free phenol content were obtained, the product was taken out from the reaction vessel to obtain 1466 parts of a solid alkylbenzene-modified novolac resin A41 having a modification rate of 41% with alkylbenzene.

<Production Example 2>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol and 1200 parts of xylene resin ("Nikanol H" manufactured by Mitsubishi Gas Chemical Co., Ltd.), 5 parts of oxalic acid was added, and the reaction was carried out at 97-103 ° C for 5 hours. Then, after dehydrating and dephenoling under reduced pressure until the desired water content and free phenol content were obtained, the product was taken out from the reaction vessel to obtain 1820 parts of a solid alkylbenzene-modified novolak resin B having a modification rate of 66% with alkylbenzene.

<Production Example 3>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol and 600 parts of mesitylene resin ("Nikanol M" manufactured by Mitsubishi Gas Chemical Co., Ltd.), 5 parts of oxalic acid was added, and the reaction was carried out at 97-103 ° C for 3 hours. . Thereafter, 5 parts of oxalic acid and 350 parts of 37% formalin were gradually added, and the reaction was carried out at 97-103 ° C. for 2 hours. Thereafter, dehydration and dephenolization were performed under reduced pressure until the desired water content and free phenol content were obtained, and then the product was taken out from the reaction vessel to obtain 1428 parts of a solid alkylbenzene-modified novolak resin C42 having a modification rate of 42% with alkylbenzene.

<Production Example 4>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol and 10 parts of oxalic acid, the internal temperature was raised to 100 ° C., 690 parts of 37% formalin was added successively over 2 hours, and then refluxed for 1 hour. Went. Then, after dehydrating and dephenoling under reduced pressure until the desired water content and free phenol content were obtained, the contents were taken out to obtain 1050 parts of an unmodified solid novolac resin.

2. Production of resole resin <Production Example 5>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol and 600 parts of xylene resin ("Nikanol H" manufactured by Mitsubishi Gas Chemical Co., Ltd.), 5 parts of oxalic acid was added, and the reaction was carried out at 97-103 ° C for 3 hours. . Thereafter, after cooling to an internal temperature of 50 ° C., 25 parts of 28% ammonia water and 440 parts of 37% formalin were added, followed by heating and reaction at 80 to 85 ° C. for 15 minutes. Thereafter, dehydration and dephenolization were performed under reduced pressure until a desired water content and free phenol content were obtained, and then the contents were taken out to obtain E1511 parts of a solid alkylbenzene-modified resole resin having a modification rate of 40% with alkylbenzene. .

<Production Example 6>
A reaction vessel equipped with a cooler and a stirrer was charged with 1000 parts of phenol, 10 parts of 50% sodium hydroxide, and 1035 parts of 37% formalin, and reacted at an internal temperature of 98 to 100 ° C. for 30 minutes. After cooling to an internal temperature of 50 ° C., 20 parts of 28% aqueous ammonia was added and heated, and the reaction was carried out at 80 to 85 ° C. for 15 minutes. Thereafter, dehydration and dephenolization were performed under reduced pressure until the desired water content and free phenol content were obtained, and then the contents were taken out to obtain 1012 parts of an unmodified solid resol resin F1012.

3. Preparation of composition <Example 1>
70 parts of solid novolak resin A prepared in Production Example 1 and 30 parts of solid resol resin E prepared in Production Example 5 were mixed and pulverized to obtain a powdery phenol resin mixture. 100 parts of this mixture was mixed with 50 parts of sodium hexametaphosphate and 50 parts of calcium hydroxide, and 10 parts of water was added thereto and mixed at room temperature for 30 seconds to obtain a composition.

<Example 2>
Example except that the powdered phenol resin mixture was prepared by mixing and grinding 90 parts of the solid novolak resin A prepared in Production Example 1 and 10 parts of the solid resol resin E prepared in Production Example 5. A composition was obtained in the same manner as in 1.

<Example 3>
90 parts of the solid novolak resin B prepared in Production Example 2 and 10 parts of the solid resol resin E 10 prepared in Production Example 5 were mixed and ground to obtain a powdery phenol resin of the present invention.

<Example 4>
90 parts of the solid novolak resin B prepared in Production Example 2 and 10 parts of the solid resol resin F prepared in Production Example 6 were mixed and ground to obtain a powdery phenol resin of the present invention.

<Example 5>
90 parts of the solid novolak resin C prepared in Production Example 3 and 10 parts of the solid resol resin E 10 prepared in Production Example 5 were mixed and ground to obtain a powdery phenol resin of the present invention.

<Comparative example>
90 parts of solid novolak resin D prepared in Production Example 4 and 10 parts of solid resol resin F prepared in Production Example 6 were mixed and ground to obtain a powdery phenol resin.

  Examples 1 to 5 and the ratio of the alkylbenzene modification of the phenol resin obtained in the comparative example, the carbonization rate, the results of evaluating the foamability, and the indeterminate form obtained in Examples 1 to 5 and the comparative example The results of evaluating the curability of the refractory binder composition are shown in Table 1.

<Characteristic evaluation>
(1) Ratio of alkylbenzene modification: The content of the alkylbenzene resin used in producing the alkylbenzene-modified phenol resin with respect to the total amount of the novolak resin and the resol resin was calculated in%.
(2) Carbonization rate of resin: The resin was put in a crucible, heated at 135 ° C. for 1 hour, further heated at 430 ° C. for 30 minutes, then covered with a crucible, and further heated in coke at 800 ° C. for 30 minutes. The carbonization rate was calculated by dividing the weight of the sample after heating at 800 ° C. for 30 minutes by the weight of the resin charged in the crucible.
(3) Curability: 10 parts of water was added to the binder composition for amorphous refractory blended as described above, mixed for 30 seconds, allowed to stand at room temperature for 30 minutes, and the state was observed.
(4) Foaming property: 1.0 g of a sample was placed in an aluminum cup having a diameter of 40 mm, and the state after heating at 200 ° C. for 60 minutes was visually observed. The case where the height of the sample after heating was less than 20 mm was set to “small”, and the case where the height was 20 mm or more was set to “large”.

  Examples 1 to 5 are compositions of the present invention characterized in that the phenolic resin contains a novolak resin and a resole resin, and the novolac resin and / or the resole resin is an alkylbenzene-modified resin, and hexametaphosphoric acid When soda was used in combination, it was cured at room temperature. In contrast, the comparative example in which the unmodified novolak resin and the unmodified resole resin were blended remained soft at room temperature and did not cure.

Claims (8)

A binder composition for use in an amorphous refractory, comprising a sodium phosphate salt, a divalent metal salt, and a phenol resin, wherein the phenol resin contains an alkylbenzene-modified phenol resin. A binder composition for regular refractories. The binder composition for an amorphous refractory according to claim 1, wherein the phenol resin has an alkylbenzene modification rate of 30 wt% to 80 wt% with respect to the entire phenol resin. The binder composition for an amorphous refractory according to claim 1 or 2, wherein the phenol resin contains a novolac type phenol resin and a resol type phenol resin. The binder for an amorphous refractory according to claim 3, wherein a weight blending ratio of the novolac-type phenol resin and the resol-type phenol resin is novolak-type phenol resin / resole-type phenol resin = 95/5 or more and 50/50 or less. Composition. The binder composition for an amorphous refractory according to any one of claims 1 to 4, wherein the alkylbenzene-modified phenolic resin includes a product obtained by reacting an alkylbenzene resin with phenols. The bond for an amorphous refractory according to any one of claims 1 to 5, wherein the alkylbenzene-modified phenol resin includes a product obtained by reacting an alkylbenzene resin with a phenol and further reacting with an aldehyde. Agent composition. The binder composition for an amorphous refractory according to claim 5 or 6, wherein the alkylbenzene resin includes one obtained by reacting one or more selected from toluene, xylene, and mesitylene with formaldehyde. The weight blending ratio of the sodium phosphate salt and the phenol resin is sodium phosphate salt / phenol resin = 10/2 or more and 10/8 or less, for an amorphous refractory according to any one of claims 1 to 7. Binder composition.