JP2003238262A - Baking repairing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a baking repairing material having excellent characteristic. <P>SOLUTION: The baking repairing material consists of 5-30% pitch, 1-20% terpene-phenol resin and the balance mainly made up of refractory aggregate by mass ratio. The baking repairing material consists of 5-30% pitch, 1-20% rosin and the balance mainly made up of refractory aggregate by mass ratio. The baking repairing material uses a rosin derivative or a rosin-modified resin as the rosin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bake repair material for hot repairing refractory linings in various molten metal refining furnaces and molten metal containers used in the iron and steel industry.

[0002]

2. Description of the Related Art One of the hot repair methods for lined refractory materials is to repair and repair the locally melt-damaged part by utilizing the residual heat of the repaired part to melt and solidify the repair material made of irregularly shaped refractory material. There is a baking repair method.

As the characteristics of the bake repair material used for this bake repair, the fluidity due to melting due to residual heat has a good filling property for the locally melted portion, and is excellent in adhesiveness with the object to be repaired. And forming a strong repair work body,
Further, the baking time until melting, adhesion and solidification may be short.

[0004] In recent years, the linings of molten metal refining furnaces and molten metal containers often use carbon-based refractory materials typified by magnesia carbon. Looking at it, a material that forms a carbon bond hot is desirable. Therefore, the conventional bake repair material generally uses a pitch having a high fixed carbon amount and forming a strong carbon bond as a binder. Also, for the purpose of shortening the fluidity and baking time during construction,
A fluidization aid has been added.

For example, Japanese Patent Application Laid-Open No. 6-157149 discloses a bake repair material in which pitch, tar, phenol resin or the like is used as a binder and lactams are added as a fluidization aid.

In Japanese Patent Laid-Open No. 9-87725, pitch or phenol resin is used as a binder, and as a fluidization aid,
A combination of wax or paraffin is added to the terpene resin.

[0007]

However, conventional baking repair materials are not sufficient in fluidity, shortening of baking time, and adhesive strength, and the effect of the pitch for forming a strong carbon bond is not utilized.

[0008] Using lactams as fluidization aids
Since the material of 7149 publication has high hygroscopicity of lactams,
The baking repair material induces a solidification phenomenon due to moisture absorption during storage, resulting in deterioration of fluidity during construction. Especially, this phenomenon is remarkable in the hot and humid summer. Further, as the solidification proceeds, the baking function is impaired, the baking time becomes longer, and the adhesive strength also decreases.

The material of JP-A-9-87725, in which a terpene resin having a remarkable decrease in melt viscosity and another fluidizing aid are used as the fluidizing aid, has a structure in which the fluidizing aid is a repair material structure due to heat received during construction. It is separated and washed out early and is inferior in effect as a fluidization aid. As a result, fluidity, shortening of baking time, and adhesive strength are insufficient.

It is an object of the present invention to provide a baking repair material having excellent characteristics, which has improved the above conventional problems.

[0011]

A feature of the present invention is a baking repair material mainly composed of a pitch 5 to 30%, a terpene phenol resin 1 to 20%, and the rest being a refractory aggregate in a mass ratio. . Also, in the mass ratio, pitch 5
~ 30%, rosin 1 ~ 20%, the rest is a bake repair material mainly made of refractory aggregate. Further, the rosin is a baking repair material which is a rosin derivative or a rosin-modified resin.

The terpene resin has a low compatibility with pitch,
Like other conventionally known fluidization aids such as wax and paraffin, it separates and flows out from a relatively low temperature range, so most of it has already disappeared in the temperature range where the pitch melts, and it is sufficient for the fluidity of the baking repair material. Does not contribute. For example, when a large amount of terpene resin is added, the above phenomenon is alleviated, but the deterioration of the structure of the baked product leads to deterioration of the durability of the baked repair material.

The terpene phenol resin used in the present invention is a copolymer of a terpene resin and a phenol resin. Terpene phenol resin has a wide melting temperature range, does not separate and flow out early, and when the pitch melts, the effect of compatibility between the pitch and the terpene resin is exerted, and the fluidity of the baking repair material is significantly improved. You can

Generally, the compatibility with pitch tends to increase as the number of benzene rings held in the resin molecule increases. With respect to the terpene phenol resin, the number of benzene rings contained in the resin molecule increases and the compatibility with pitch also increases due to the copolymerization reaction with phenol. It is considered that this acts to prevent the early outflow of the terpene phenol resin.

On the other hand, rosin is also superior to terpene resin in compatibility with pitch. This has a structure with advanced cyclization of resin acid and has few side chains. As a result, the compatibility with the pitch is increased, and like the terpene phenol resin, it does not separate and flow out at an early stage, and acts to improve the fluidity of the baking repair material.

The softening point of rosin is a low temperature of 73 to 90 ° C. as a fluidization aid, and since the melting temperature range is wide, a compatibility reaction with pitch occurs from the low temperature range, The timing of melting and fluidizing the baking material is accelerated,
Effective in shortening baking time.

Further, both of the above terpene phenol resin and rosin have compatibility with pitch, so that the viscosity of the pitch when melted and fluidized becomes low, the wettability with the surface to be repaired increases, and the baking repair material Further improve the adhesive strength.

Furthermore, these terpene phenolic resins and rosins have extremely low hygroscopicity. Therefore, there is no problem found in lactams such as deterioration of fluidity and adhesive strength of a baking repair material due to moisture absorption and solidification during storage, or long baking time.

In the present invention, even when a rosin derivative or a rosin-modified resin is used instead of rosin, the above-described effects of rosin can be obtained.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The pitch used in the present invention is the same as the conventional bake repair material in terms of material and ratio.
It is preferable that the softening point is 80 to 150 ° C. If the softening point is too low, the bake repair material may be solidified during storage. If the softening point is too high, the seizure time becomes long, which is not preferable.

If the proportion of pitch is less than 5% by mass, the fluidity, corrosion resistance and adhesive strength of the bake repair material will be poor. 30% by mass
If it exceeds, the porosity of the construction body is increased and the corrosion resistance is deteriorated.

The pitch can also be used by combining different types of softening points. The mixing ratio is not particularly limited,
Considering the fluidity during hot, it is desirable to increase the amount of the low softening point pitch.

The terpene phenol resin as a fluidization aid can be obtained by copolymerizing a terpene resin and a phenol resin.

The terpene resin used for producing the terpene phenol resin is a purified polymer of α-pinene and β-pinene obtained from pine essential oil and the like. In addition, a synthetic terpene having a similar structure to a natural terpene resin can be obtained from a polyterpene resin synthesized from terpene oil or the like or a C5 fraction obtained by decomposition of naphtha.

The terpene phenolic resin has a softening point of
Taking a terpene phenolic resin at 95 ° C as an example, 500 parts by mass of toluene, 940 parts by mass of phenol and 10 parts by mass of aluminum trichloride are charged into a reaction vessel, and 700 parts by mass of β-pinene are stirred at an internal temperature of 40 ° C. It takes about 90 minutes to carry out dropwise polymerization, and further reacts at 40 ° C. for 3 hours. After completion of the reaction, 1000 ml of water is added, the mixture is washed with water, the catalyst is removed, and the mixture is dewatered at 230 ° C. under a reduced pressure of 10 Torr.

The softening point of the terpene phenol resin is about 80-
It is 130 ℃. Among them, those used in the present invention are 90 to 1
Those that melt and fluidize at a temperature of 10 ° C are desirable.

Rosin is a pale yellow to brown transparent thermoplastic resin. There are three types: gum rosin made from raw pine resin, wood rosin obtained by extracting a pine stump with a petroleum solvent, and tall oil rosin obtained from a waste liquid during the production of kraft pulp. Its composition is mainly composed of resin acids such as abietic acid and levopimaric acid.

The rosin has a softening point of 73 to 90 ° C., has a very high compatibility with the pitch, and melts with the pitch in a hot state.
It exerts an excellent effect on the flow promoting action of the bake repair material. Among them, the rosin used in the present invention is preferably one that melts and fluidizes at a temperature of 80 to 90 ° C.

The rosin derivative is obtained by cross-linking a double bond using ester gum obtained by esterifying a rosin with an alcohol such as methanol, glycols, glycerin, pentaerythritol and the unsaturation of abietic acid contained in rosin. There is a polymerized rosin obtained.

Regarding gum rosin ester gum as an example of the method for producing a rosin derivative, gum rosin is added to a reaction vessel at 500 g.
Charge 60 parts by mass and heat up to 200 ° C in about 60 minutes,
After adding 60 parts by mass of glycerin under melting and stirring, 270 ° C
By raising the temperature to 10 and carrying out an esterification reaction for 10 hours,
Rosin ester having a softening point of 90 ° C. is obtained.

The rosin derivative has a softening point of 70 to 140 ° C., among which the rosin derivative used in the present invention is 90 to 11 ° C.
Those that melt and fluidize at a temperature of 0 ° C are desirable. The rosin derivative has a very high compatibility with the pitch, and is hot-melted with the pitch to exert an excellent effect on the flow promoting action of the baking repair material.

Specific examples of the rosin-modified resin include rosin-modified phenol resin, rosin-modified xylene resin, terpene resin / rosin-modified xylene resin copolymer and the like.

For example, rosin-modified phenol resin and rosin-modified xylene resin can be obtained by reacting rosin with phenol resin or xylene resin. The terpene resin / rosin-modified xylene resin copolymer is obtained by reacting the terpene resin with the rosin-modified xylene resin. These have a softening point of 70 to 140 ° C, and among them, those used in the present invention are preferably those which melt and fluidize at a temperature of 90 to 110 ° C.

Taking a rosin-modified xylene resin as an example, the production process will be described more specifically. 500 parts by mass of xylene resin, 500 parts by mass of gum rosin and 2 parts by mass of P-toluenesulfonic acid were charged into a reaction vessel, and The temperature is raised to 200 ° C over 60 minutes, and the esterification reaction is carried out for 5 hours. As a result, a rosin-modified xylene resin having a softening point of 90 ° C. is obtained.

The terpene phenol resin, rosin, rosin derivative and rosin modified resin used as a fluidization aid in the present invention may be used in combination of two or more thereof. Further, other fluidizing aids such as terpene resins, waxes, paraffins, alcohols, ethers, stearic acid, and heavy oil may be combined within a range that does not impair the effects of the present invention.

The proportion of fluidization aid used in the present invention is 1
If it is less than 20% by mass, the effect of compatibility with pitch and the effect of promoting carbonization of pitch cannot be sufficiently obtained. More preferably, it is 1 to 15 mass%. The particle size is not particularly limited, but is, for example, 5 mm or less, preferably 3 mm or less.

The refractory aggregate is, for example, commonly used magnesia such as sintered magnesia, seawater magnesia, electrofused magnesia, and light burned magnesia, spinel material such as sintered spinel and electrofused spinel, sintered alumina, Alumina such as fused alumina and calcined alumina can be used alone or in combination. The particle size is, for example, 13 mm or less, and considering the fluidity, the particle size composition ratio of the aggregate is 1 mm.
40 to 70% by mass above, 20 to 40% by mass below 1 mm, 0.075 m
It is better to combine m or less in the range of 10 to 20 mass%.

If necessary, metal powder may be further added for the purpose of preventing oxidation of carbon bonds. A specific example of the metal powder is Al, Si, Mg, Fe or an alloy of a combination thereof. Examples of alloys include Al-M
g alloy and Al-Si alloy. The proportion of metal powder is 3% by mass or less, preferably 0.3 to 2% by mass. If the amount is small, the effect of metal addition is not exhibited, and if the amount is large, the fluidity is lowered.

The baking repair material of the present invention is a mixture of the above-mentioned compounds, and is applied while the surface to be repaired is under residual heat. After the bake repair material spreads by melt flow on the surface to be repaired, carbon bonds are formed by carbonization of the pitch and the carbon bond is adhered to the surface to be repaired to complete the repair work.

[0040]

EXAMPLES Examples of the present invention and comparative examples will be described below. Tables 1 and 2 show the compounding composition of each example of the baked repair material and the test results thereof.

[0041]

[Table 1]

[Table 2] In the test, 1 kg of the bake repair material composition of each example was applied to a refractory material horizontally installed in an experimental furnace maintained at a temperature of about 1000 ° C.

Sintered magnesia was used as the refractory aggregate, and its particle size (JIS sieve opening) was 50% by mass for 10 to 1 mm, 30% by mass for 1 mm or less, and 20% by mass for 0.075 mm or less. The pitch particle size was 2 mm or less, and the fluidization aid particle size was 3.35 mm or less. The fluidity is an index in which the maximum fluidized area ratio is determined and the maximum fluidized area ratio of Comparative Example 1 is 100. The larger the value, the better the fluidity. The baking time was the time after the construction until the smoke generation due to the burning of the binder was completed.

The adhesive strength was measured by the shearing force between the work body and the work surface of the baking repair material after the baking was completed.

The apparent porosity was determined by taking out 1 kg of the sample prepared in a 100 × 100 × 100 mm metal frame from the furnace and cooling it.
A sample cut into a size of 20 × 20 × 20 mm was used as a sample. The apparent porosity is 11 according to the standard of JIS R2205: 92.
It was measured after drying at 0 ° C. for 24 hours.

In the above-mentioned test, the bake repair material was measured immediately after kneading and then applied, whereas in the test of aging, the bake repair material was placed in a constant temperature and humidity chamber at 40 ° C. and a humidity of 90%. It was measured after being left for 48 hours and then applied. It was confirmed that changes in baking time and fluidity due to changes with time were confirmed by the construction after leaving.

In each of the examples, the baking time was short and excellent fluidity was obtained. Good results were also obtained for fluidity, adhesive strength and apparent porosity. Further, in the examples, even after long-term storage under high temperature and high humidity conditions, there was no change with time, and good baking workability was obtained. On the other hand, Comparative Example 1 uses ε-caprolactam, and its water absorption causes a remarkable change over time, resulting in poor fluidity and poor adhesive strength during construction after the change over time.

In Comparative Example 2 using the terpene resin and Comparative Example 4 using the terpene resin and the wax together, inferior compatibility with the pitch results in baking time, fluidity,
Poor in adhesive strength and apparent porosity.

Comparative Example 3 uses a terpene phenol resin, Comparative Example 5 uses a combination of a terpene resin and wax, and Comparative Example 6 uses a rosin, both of which are used in combination with a thermoplastic phenol resin. However, the fluidity during hot is inferior and the adhesive strength is not sufficiently exhibited.

In Comparative Example 7 and Comparative Example 8, the amounts of the terpene phenol resin and rosin used were larger than the ranges limited by the present invention, and as a result, the apparent porosity was high.

[0050]

As shown by the test results of the above examples, the bake repair material of the present invention has extremely excellent effects on fluidity, adhesive strength, corrosion resistance and shortening of baking time required for the bake repair material. Demonstrate. Further, since there is substantially no change with time, stable properties can be obtained even after long-term storage, and manufacturing control is easy.

Continued front page    (72) Inventor Isamu Ide             2-5 Chikko Shinmachi, Sakai City, Osaka Prefecture             Inside the corporation (72) Inventor Naoto Higuchi             2-5 Chikko Shinmachi, Sakai City, Osaka Prefecture             Inside the corporation F-term (reference) 4G033 AA03 AB24 AB25 BA02                 4K051 LJ01

Claims (3)

[Claims] 1. A baking repair material mainly composed of a pitch of 5 to 30%, a terpene phenol resin of 1 to 20% and a balance of refractory aggregate in a mass ratio. 2. A bake repair material mainly composed of a pitch of 5 to 30%, a rosin of 1 to 20%, and a balance of refractory aggregate in mass ratio. 3. The baking repair material according to claim 2, wherein the rosin is a rosin derivative or a rosin-modified resin.