JP2019158240A - Press-fit material - Google Patents

Abstract

To suppress a foam phenomenon and to realize the improvement of thermal conductivity in a press-fit material filled to a gap in a blast furnace wall.SOLUTION: A press-fit material comprises: a graphite refractory aggregate; and a liquid phenolic resin made of a phenolic resin and a solvent. In the solvent of the liquid phenolic resin by 100 mass%, ester having a boiling point of 150 to 350°C is contained by 30 mass% or higher, and the graphite refractory aggregate contains spherical graphite by 5 mass% or higher in the graphite refractory aggregate by 100 mass%.SELECTED DRAWING: None

Description

  The present invention relates to a press-fitting material filled in a gap between blast furnace walls, particularly a back surface of a lining refractory constituting the blast furnace wall. In the present invention, the blast furnace wall is a concept including the bottom of the blast furnace.

  2. Description of the Related Art Conventionally, a technique of filling a press-fit material in a blast furnace furnace wall in order to reduce wear of the lining refractory is known. This press-fit material is mainly composed of a graphite fireproof aggregate from the viewpoint of ensuring thermal conductivity, and a binder is added thereto. In general, tar or liquid thermosetting resin is used as the binder.

  However, a press-fit material using tar as a binder is not preferable in terms of working environment because tar contains a large amount of benzpyrene, which is a carcinogenic substance. Further, since tar has a property of being in a liquid state at 400 ° C. or lower, it does not sufficiently cure even after filling in the gap, and it cannot be said that the thermal conductivity required for the press-fit material is sufficient.

  On the other hand, a press-fitting material using a liquid thermosetting resin as a binder is advantageous in the working environment because it contains almost no harmful substances, and is easy to adjust the viscosity, and further has the advantage that press-fitting at room temperature is possible. Yes. However, especially when the atmosphere temperature of the gap to be pressed is high, when using a liquid thermosetting resin, the curing of the surface layer part that touches the lining refractory precedes the curing inside, in the process of curing the pressed material, Furthermore, there has been a problem that a foaming phenomenon occurs in which the foaming occurs with boiling. When such a foaming phenomenon occurs, since the press-fit material structure becomes porous, the effect of improving the thermal conductivity by the graphite refractory aggregate is not sufficiently exhibited, leading to a decrease in thermal conductivity. .

  On the other hand, Patent Document 1 proposes that a liquid novolac type phenol resin and a powdered phenol resin are used in combination as a binder of the press-fitting material in order to suppress the foaming phenomenon of the press-fitting material. Further, Patent Document 1 describes that a glycol-based solvent (ethylene glycol, diethylene glycol, triethylene glycol, etc.) is used as an example of a solvent for a liquid novolak type phenol resin.

  However, as a result of examining the glycol-type solvent as the solvent of the phenol resin by the present inventors, the foaming phenomenon was still observed. As a result, the thermal conductivity of the press-fit material was not at a sufficient level.

Japanese Unexamined Patent Publication No. 2000-233977

  The problem to be solved by the present invention is to suppress the foaming phenomenon in the press-fitting material filled in the gap between the blast furnace furnace walls and to realize the improvement of the thermal conductivity.

  As a result of intensive studies by the present inventors in order to solve the above problems, the foaming phenomenon of the press-fitting material by using a liquid phenol resin containing an ester having a boiling point of 150 ° C. or higher and 350 ° C. or lower as a solvent as the binder of the press-fitted material. In addition, the use of graphite fireproof aggregates combined with the effect of suppressing the foaming phenomenon led to the finding that the thermal conductivity of the press-fit material can be improved.

  That is, the press-fitting material of the present invention is a press-fitting material filled in the gap of the blast furnace furnace wall, and includes a graphite refractory aggregate and a liquid phenol resin composed of a phenol resin and a solvent. In 100% by mass of the solvent, 30% by mass or more of an ester having a boiling point of 150 ° C. or more and 350 ° C. or less is contained, and the graphite-based refractory aggregate contains 5 mass of spherical graphite in 100% by mass of the graphitic refractory aggregate. % Or more.

  According to the present invention, the foaming phenomenon during construction of the press-fit material can be suppressed, and the thermal conductivity can be improved.

It is an image figure which shows the thermal conductivity improvement effect by spherical graphite. It is a figure which shows a time-dependent change of the mass increase rate of the liquid phenol resin in relative humidity 66%. It is a figure which shows a time-dependent change of the mass increase rate of the liquid phenol resin in relative humidity 92%.

  As described above, the press-fitting material of the present invention comprises a graphite fireproof aggregate and a liquid phenol resin.

  The first feature of the present invention is that the liquid phenol resin as a binder contains an ester having a boiling point of 150 ° C. or higher and 350 ° C. or lower as a solvent. Thereby, the foaming phenomenon at the time of construction of a press-fit material can be suppressed. The reason is estimated as follows.

  The glycol solvent used in Patent Document 1 described above has a large number of two hydrophilic hydroxyl groups in one molecule. For example, in the case of ethylene glycol, there are two hydroxyl groups in the molecular weight 62. On the other hand, the ester solvent used in the present invention has few hydroxyl groups and does not dissolve in water, and therefore has a low hygroscopic property.

  That is, when a glycol system is used as a solvent for a liquid phenolic resin, the solvent and water azeotrope due to moisture absorption of the solvent, and the solvent volatilizes at a low temperature, and the phenol resin is cured and solidified (hereinafter simply referred to as “curing”). .) Will be faster. Therefore, the resin in the surface layer portion of the press-fitting material that contacts the lining refractory hardens, and the volatile components of the resin inside the press-fitting material volatilize at a time, thereby causing foaming. In contrast, when an ester is used as the solvent, moisture absorption is small, and the solvent volatilizes gradually without lowering the solvent's volatilization temperature, which slows the curing of the resin. Therefore, the residual volatile content after the resin is cured is reduced and foaming is less likely to occur.

  On the other hand, when the boiling point of the solvent is lower than 150 ° C., the solvent is volatilized at a low temperature, so that the fluidity is deteriorated and the filling property is deteriorated. Furthermore, since the volatilization of the solvent is accelerated, the phenol resin is quickly cured and easily foams.

  On the other hand, a solvent having a boiling point exceeding 350 ° C. has a higher viscosity than that of a low-boiling solvent, and the solubility of the resin to be blended when producing a liquid phenolic resin is reduced. When the amount is set, the viscosity of the liquid phenol resin obtained by dissolution increases. When the viscosity of the liquid phenol resin is increased, the filling property of the press-fit material is deteriorated, and the press-fit is difficult. Moreover, when the viscosity of a liquid phenol resin is made low from the surface of a filling property, the resin amount mix | blended when manufacturing a liquid phenol resin decreases. In other words, the amount of solvent increases, and the amount of fixed carbon in the liquid phenol resin obtained by manufacturing decreases. Further, the volatilization of the solvent contained in the liquid phenol resin increases the voids in the press-fit material structure, and the amount of fixed carbon decreases, resulting in a decrease in thermal conductivity. Accordingly, the boiling point of the solvent needs to be 150 ° C. or higher and 350 ° C. or lower.

  Examples of the ester having a boiling point of 150 ° C. or higher and 350 ° C. or lower (hereinafter referred to as “ester in a specific boiling range”) include 3-methoxybutyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, benzyl acetate, Isopentyl propionate, butyl butyrate, isopentyl butyrate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, inpentyl benzoate, diethyl oxalate, diethyl malonate, dimethyl maleate, diethyl maleate, dibutyl maleate , Dimethyl phthalate, diethyl phthalate, ethylene glycol monoacetate, ethyl diacetate, triacetin, ethylene carbonate, propylene carbonate, gamma butyrolactone, dimethyl glutarate, dimethyl succinate, Dimethyl dipinate, dibutyl phthalate, dibutyl tartrate, benzyl benzoate, pentyl acetate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, etc. .

  These esters having a specific boiling range can be used alone, but can also be used as a mixed solvent in which a plurality of esters having a specific boiling range are mixed. In the case of using a mixed solvent, it is preferable to use a combination of plural kinds of esters having a specific boiling range with different boiling points.

  Moreover, in this invention, 30 mass% or more of ester of a specific boiling range is contained in 100 mass% of solvents of a liquid phenol resin. If the content of the ester in the specific boiling range in 100% by mass of the solvent of the liquid phenolic resin is less than 30% by mass, the moisture absorption suppressing effect cannot be sufficiently obtained, and volatilization occurs due to moisture absorption by the solvent, resulting in foaming. Furthermore, since the hygroscopicity of the solvent is further suppressed when 50 mass% or more of the ester in the specific boiling range is contained in 100 mass% of the solvent of the liquid phenol resin, the ester of the specific boiling range is 100 mass of the solvent of the liquid phenol resin. It is preferable to use so that 50 mass% or more may be occupied in%.

  In the present invention, as the solvent for the liquid phenolic resin, other solvents can be used in combination with the ester having the specific boiling range. In this case, the boiling point of the solvent used in combination is preferably 150 ° C. or higher and 350 ° C. or lower. Examples of solvents that can be used at a boiling point of 150 ° C. or higher and 350 ° C. or lower include 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, and 2-ethyl- for alcohols. 1-hexanol, 1-nonanol, 1-decanol, benzyl alcohol, cyclohexanol, furfuryl alcohol, polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, tetraethylene glycol, butanediols, pentamethylene glycol Hexylene glycol, octylene glycol, glycerin, and ketones include 2-heptanone, diisobutyl ketone, isophorone, cyclohexanone, methylcyclohexanone, acetophenone, The ether compounds, 1,2-dibutoxyethane, diethylene glycol ethers, furfural, and the like. Among these solvents, solvents that are difficult to absorb moisture are preferable. These solvents that can be used in combination can be used alone or as a mixed solvent in which a plurality of solvents are mixed.

  In addition, the mass ratio of the resin component and the solvent component in the liquid phenol resin is 30:70 to 70:30 in terms of resin: solvent from the viewpoints of securing an appropriate amount of fixed carbon and securing an appropriate viscosity. preferable.

  In the present invention, a resin for producing a liquid phenol resin can be prepared by reacting phenols and aldehydes in the presence of a reaction catalyst.

  Here, the phenols used in the resin for producing the liquid phenolic resin mean phenol and phenol derivatives. For example, in addition to phenol, m-cresol, resorcinol, 3,5-xylenol and the like 3 Functional, tetrafunctional such as bisphenol A, dihydroxydiphenylmethane, o-cresol, p-cresol, p-ter-butylphenol, p-phenylphenol, p-cumylphenol, p-nonylphenol, 2 Bifunctional o- or p-substituted phenols such as 1, 4 or 2,6-xylenol, and halogenated phenols substituted with chlorine or bromine can be used. Of course, one type can be selected and used, or a plurality of types can be mixed and used.

  Also, as the aldehydes used in the resin for producing the liquid phenolic resin, formalin which is in the form of an aqueous solution is optimal, but those in the form of paraformaldehyde, acetaldehyde, benzaldehyde, trioxane, tetraoxane may be used. In addition, it is also possible to replace part of formaldehyde with 2-furaldehyde or furfurylaldehyde. Of course, one type can be selected and used, or a plurality of types can be mixed and used.

  The mixing ratio of the above phenols and aldehydes is not particularly limited, but the molar ratio of phenols and aldehydes is set to be in the range of 1: 0.3 to 1: 3.5. preferable. If the amount of aldehyde used is less than 0.3 mol, the remaining unreacted phenols increase, which is not efficient. On the other hand, if the amount of aldehyde used exceeds 3.5 mol, the remaining unreacted aldehyde increases, which is not efficient.

  As a reaction catalyst, when preparing a novolak-type phenol resin, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as oxalic acid, paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid, and acetic acid A divalent metal salt such as zinc can be used.

  When preparing a resol-type phenolic resin, alkaline earth metal oxides and hydroxides can be used, and aliphatic dimethylamine, triethylamine, butylamine, dibutylamine, tributylamine, diethylenetriamine, dicyandiamide and the like. Primary, secondary, tertiary amine, aliphatic amines having aromatic rings such as N, N-dimethylbenzylamine, aromatic amines such as aniline and 1,5-naphthalenediamine, ammonia, hexamethylenetetramine, etc. Other divalent metal hydroxides and divalent metal salts can also be used.

  In order to improve the adhesion between the refractory aggregate and the liquid phenol resin, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, etc. A coupling agent can also be added and used.

  As the phenolic resin of the liquid phenolic resin of the present invention, a resin that is hard to be cured at a low temperature so that the press-fitting material can be filled up to the gap of the blast furnace furnace wall is preferable, and a novolac type phenolic resin is suitable as the type of phenolic resin.

However, in order to improve the thermal conductivity of the press-fit material in a low temperature range, for example, a temperature range of 200 ° C. or lower, a resol type phenol resin that promotes the hardening of the press-fit material may be used in combination. When a resol type phenol resin is used in combination, the amount of fixed carbon increases, voids after carbonization decrease, and the effect of improving thermal conductivity is also obtained. The proportion of the resol type phenol resin in 100% by mass of the phenol resin of the liquid phenol resin is preferably 40% by mass or less. When the amount exceeds 40% by mass, the press-fit material is hardened quickly, and the filling property of the press-fit material may be deteriorated. Moreover, in order to fully exhibit the effect of increasing the fixed carbon amount by the addition of the resol type phenol resin, the ratio of the resol type phenol resin in 100% by mass of the phenol resin of the liquid phenol resin is preferably 5% by mass or more.
As the resol type phenol resin, a benzylic ether type having a slow curing rate is suitable.

  Combinations and addition ratios of the above solvents and phenol resins are adjusted so as to obtain an appropriate boiling point within the scope of the present invention.

  The second feature of the present invention is that the graphite-based refractory aggregate used for ensuring thermal conductivity contains 5% by mass or more of spherical graphite in 100% by mass of the graphitic refractory aggregate. Thereby, the thermal conductivity of the press-fit material can be improved.

  The reason will be described with reference to FIG. Since general graphite has a flat shape (flat plate shape) as shown in FIG. 1A, orientation occurs in the graphite arrangement, so that the heat conduction path is blocked and heat is not easily transmitted. On the other hand, when spherical graphite is used, the heat conduction path is easily connected as shown in FIG. Thereby, the thermal conductivity of the press-fit material is improved.

  In addition, since spherical graphite has an effect of improving the fluidity of the press-fitting material, an effect of reducing the amount of liquid phenol resin used as a binder can be obtained. If the amount of liquid phenol resin used is small, foaming during construction is less likely to occur, and a sound press-fit material structure can be obtained. This also improves the thermal conductivity of the press-fit material. That is, in the present invention, the use of a liquid phenol resin containing an ester having a specific boiling range as a solvent and the use of spheroidal graphite can be combined to suppress the foaming phenomenon during construction of the press-fit material, and the heat conduction of the press-fit material. Improves.

  Spherical graphite is used in an amount of 5% by mass or more in a proportion of 100% by mass of the graphite-based refractory aggregate. If the amount used is less than 5% by mass, the above-described effect of improving thermal conductivity cannot be obtained. There is no particular upper limit on the amount of spheroidal graphite used, and all of the graphite fireproof aggregate may be spheroidal graphite. The particle size of the spherical graphite is preferably 5 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

  The spherical graphite does not have to be completely spherical, and the surface shape only needs to form a curved surface. In terms of aspect ratio (maximum major axis of particle / width perpendicular to the major axis), 1 to 5 is preferable, and 1 to 2 is more preferable.

  The mixing ratio of the graphite fireproof aggregate and the liquid phenolic resin in 100% by mass of the press-fit material may be the same as that of a normal press-fit material. For example, the graphite fireproof aggregate is 5% by mass to 70% by mass. Hereinafter, the liquid phenol resin is 30% by mass or more and 95% by mass or less.

  The graphite fireproof aggregate used in the present invention may be one or more selected from natural graphite, earthy graphite, artificial graphite, scale-like graphite, laminated graphite and the like.

  In addition to the graphite, the refractory aggregate used in the present invention may be one or more selected from silicon carbide, calcined anthracite, coke, electrode powder, carbon black and the like. Moreover, it may be used for some refractory raw materials such as alumina, silica, magnesia, spinel and other crushed raw materials and spherical raw materials, but when these are used, 50 mass% or less is preferable and 20 mass% or less is more preferable. The particle size of the refractory aggregate is preferably 1 mm or less. More preferably, it is 0.3 mm or less. That is, since the gap between the blast furnace furnace walls is narrow, it is preferable that the particle size of the refractory aggregate is small from the viewpoint of ensuring sufficient fillability.

  Moreover, the press-fitting material of the present invention can also include materials other than refractory aggregates such as graphite refractory aggregates and liquid phenolic resins. For example, metal powder, a hardening accelerator, powdered phenol resin, pitch, etc. are mentioned. These can be blended in the range of, for example, 0.1% by mass or more and 5% by mass or less with respect to 100% by mass of the press-fitting material.

  The press-fitting material of the present invention is typically obtained by mixing a graphite refractory aggregate and a liquid phenolic resin with a mixer or the like, but mixes a graphite refractory aggregate and a phenolic resin. It can also be obtained by sometimes adding a solvent and mixing and dissolving them.

  First, liquid phenolic resins A to K used in Examples and Comparative Examples of the present invention described later were prepared (see Table 1). That is, the liquid phenol resins A to K used in Examples and Comparative Examples of the present invention have a solvent amount so that the viscosity at 25 ° C. is 200 to 350 mPa · s in order to make the fluidity of the press-fit material the same level. Prepared as follows. Moreover, the viscosity and the amount of fixed carbon of the liquid phenol resin were measured according to JIS K6910.

(Liquid phenol resin A)
A reaction vessel was charged with 940 parts by weight of phenol, 608 parts by weight of 37% formalin, and 5.6 parts by weight of oxalic acid, refluxed for about 60 minutes, allowed to react for 180 minutes, and then water and unreacted phenol were added. Distilled off to obtain a novolac type phenol resin having a softening point of 85 ° C.
The reaction vessel is charged with 40 parts by mass of the above-described novolak-type phenolic resin and 60 parts by mass of propylene carbonate (boiling point 242 ° C.) as an ester having a specific boiling range, and the temperature is raised to 90 ° C. in about 60 minutes and maintained for 60 minutes. The liquid phenol resin A was obtained by cooling.
The viscosity of this liquid phenol resin A at 25 ° C. was 200 mPa · s, and the amount of fixed carbon at 800 ° C. was 17%.

(Liquid phenol resin B)
50 parts by mass of the same novolak type phenolic resin as the above liquid phenolic resin A as a phenolic resin and 50 parts by mass of pentyl acetate (boiling point 150 ° C.) as an ester having a specific boiling range are blended. Resin B was obtained.
This liquid phenol resin B had a viscosity at 25 ° C. of 250 mPa · s and a fixed carbon content at 800 ° C. of 21%.

(Liquid phenol resin C)
As the phenolic resin, 35 parts by mass of the same novolak type phenolic resin as the above liquid phenolic resin A and 65 parts by mass of diethyl phthalate (boiling point 295 ° C.) as an ester having a specific boiling range are blended. Phenol resin C was obtained.
This liquid phenol resin C had a viscosity at 25 ° C. of 250 mPa · s and a fixed carbon content at 800 ° C. of 15%.

(Liquid phenol resin D)
44 parts by mass of the same novolak type phenolic resin as the above liquid phenolic resin A as the phenolic resin, 28 parts by mass of propylene carbonate (boiling point 242 ° C.) as the ester having a specific boiling range, and 28 masses of furfuryl alcohol as a solvent other than the ester having the specific boiling range. The liquid phenol resin D was obtained in the same manner as the liquid phenol resin A. That is, the ratio of the ester (propylene carbonate) having a specific boiling range in the solvent 100% by mass of the liquid phenol resin D is 50% by mass.
The liquid phenol resin D had a viscosity at 25 ° C. of 230 mPa · s and a fixed carbon content at 800 ° C. of 19%.

(Liquid phenol resin E)
As a phenol resin, 32 parts by mass of the same novolak type phenol resin as the liquid phenol resin A and 68 parts by mass of dibutyl phthalate (boiling point 340 ° C.) as an ester having a specific boiling range are blended. Phenol resin E was obtained.
This liquid phenol resin E had a viscosity at 25 ° C. of 330 mPa · s and a fixed carbon content at 800 ° C. of 14%.

(Liquid phenol resin F)
9 parts by mass of a resol type phenol resin and 40 parts by mass of propylene carbonate (boiling point 242 ° C.) as an ester in a specific boiling range are blended together with 51 parts by mass of the same novolak type phenol resin as the above liquid phenol resin A as a phenol resin. In the same manner as the phenol resin A, a liquid phenol resin F was obtained.
The viscosity of this liquid phenol resin F at 25 ° C. was 210 mPa · s, and the amount of fixed carbon at 800 ° C. was 24%.

(Liquid phenol resin G)
44 parts by mass of the same novolak type phenolic resin as the above-mentioned liquid phenolic resin A as the phenolic resin, 16.8 parts by mass of propylene carbonate (boiling point 242 ° C.) as the ester in the specific boiling range, and furfuryl alcohol as a solvent other than the ester in the specific boiling range 39.2 parts by mass were blended, and a liquid phenol resin G was obtained in the same manner as the liquid phenol resin A. That is, the ratio of the ester (propylene carbonate) having a specific boiling range in 100% by mass of the solvent of the liquid phenol resin G is 30% by mass.
The viscosity of this liquid phenol resin G at 25 ° C. was 220 mPa · s, and the amount of fixed carbon at 800 ° C. was 19%.

(Liquid phenol resin H)
40 parts by mass of the same novolak type phenolic resin as the above-mentioned liquid phenolic resin A as the phenolic resin and 60 parts by mass of ethylene glycol (boiling point 198 ° C.) as a solvent other than the ester having a specific boiling range are blended, and the same as the above liquid phenolic resin A. Liquid phenolic resin H was obtained.
The viscosity of this liquid phenol resin H at 25 ° C. was 280 mPa · s, and the amount of fixed carbon at 800 ° C. was 16%.

(Liquid phenol resin I)
As a phenol resin, 45 parts by mass of the same novolak type phenol resin as the liquid phenol resin A and 55 parts by mass of butyl acetate (boiling point 126 ° C.) as an ester outside the specific boiling range are blended, and in the same manner as the liquid phenol resin A, A liquid phenolic resin I was obtained.
The liquid phenol resin I had a viscosity at 25 ° C. of 220 mPa · s and a fixed carbon content at 800 ° C. of 19%.

(Liquid phenol resin J)
27 parts by mass of the same novolak type phenolic resin as the above-mentioned liquid phenolic resin A as the phenolic resin and 73 parts by mass of dioctyl phthalate (boiling point 360 ° C.) as the ester outside the above specified boiling range are blended, and the same as the above liquid phenolic resin A Liquid phenolic resin J was obtained.
The viscosity of this liquid phenol resin J at 25 ° C. was 310 mPa · s, and the amount of fixed carbon at 800 ° C. was 11%.

(Liquid phenol resin K)
44 parts by mass of the same novolak type phenolic resin as the liquid phenolic resin A as a phenol resin, 11.2 parts by mass of propylene carbonate (boiling point 242 ° C.) as an ester having a specific boiling range, and furfuryl alcohol as a solvent other than the ester having a specific boiling range 44.8 parts by mass (boiling point: 170 ° C.) was blended, and a liquid phenol resin K was obtained in the same manner as the liquid phenol resin A. That is, the ratio of the ester (propylene carbonate) having a specific boiling range in 100% by mass of the solvent of the liquid phenol resin K is 20% by mass.
The liquid phenol resin K had a viscosity at 25 ° C. of 210 mPa · s and a fixed carbon content at 800 ° C. of 19%.

  Next, these liquid phenolic resins A to K and a graphite refractory aggregate were blended in the blending ratios shown in Table 2, and mixed with a mixer to obtain a press-fit material. And about the obtained press-fit material, the degree of foaming and thermal conductivity were evaluated.

The degree of foaming was evaluated in the following manner.
[Heating test]
(1) A pre-kneaded press-fit material is filled in a cylindrical can having a diameter of 100 mm and a height of 200 mm to a height of 150 mm.
(2) The can filled with the press-fitting material is put into a heating furnace and the temperature is raised. The heating rate is 200 ° C./hour, and the temperature is maintained at 500 ° C. The holding time is 5 hours.
(3) After holding at 500 ° C. for 5 hours, natural cooling is performed.
[Organizational evaluation]
(4) After natural cooling, the cylindrical can filled with the press-fitting material was cut in half in the vertical direction, and the degree of foaming of the structure of the press-fitting material in the entire cut surface was visually evaluated. Since the foamed tissue contains many bubbles, it can be visually distinguished from a healthy tissue that is not foamed. Specifically, among the press-fit materials on the cut surface, the foamed structure is less than 20% of the entire press-fit material on the cut surface (excellent), and the foamed structure is approximately 20% of the entire press-fit material on the cut surface. The case of less than 40% was evaluated as ◯ (good), and the case where the foamed structure was approximately 40% or more of the entire press-fit material on the cut surface was evaluated as × (impossible).

  The thermal conductivity was evaluated by measuring the thermal conductivity of a sample that had been previously heat-treated at 300 ° C. for 48 hours by the Cole Roush method. The value of the thermal conductivity of Example 1 was set to 100 and expressed in terms of an index. A high value of this thermal conductivity index means that the thermal conductivity is high, which is preferable.

In Table 2, Examples 1 to 10 are examples belonging to the scope of the present invention. The degree of foaming was small and good, and the thermal conductivity was also good. In addition, although Example 9 is outside the range of a preferable ratio (50% by mass or more) of the ester having a specific boiling point in 100% by mass of the solvent of the liquid phenolic resin, the degree of foaming and the thermal conductivity are from the comparative example. Also gave good results.
Comparative Example 1 is an example using ethylene glycol instead of an ester as a solvent, Comparative Example 2 is an example using an ester having a boiling point of less than 150 ° C., Comparative Example 3 is an example using an ester having a boiling point exceeding 350 ° C., Comparative Example 4 is an example where the amount of spheroidal graphite used is small, and Comparative Example 5 is an example where the amount of ester used in the specific boiling range is small. In both cases, the foaming phenomenon was noticeable. Moreover, the thermal conductivity index | exponent of Comparative Examples 1-5 became a value lower than Examples 1-10.

FIG. 2 shows Example 1 (Liquid phenol resin A), Example 5 (Liquid phenol resin D), Example 9 (Liquid phenol resin G), Comparative example 1 (Liquid phenol resin H) and comparison in a relative humidity 66% atmosphere. The result of having measured the mass increase rate of each liquid phenol resin of Example 5 (liquid phenol resin K) is shown. FIG. 3 shows Example 1 (Liquid phenol resin A), Example 5 (Liquid phenol resin D), Example 9 (Liquid phenol resin G), Comparative example 1 (Liquid phenol resin H) and comparison in a 92% relative humidity atmosphere. The result of having measured the mass increase rate of each liquid phenol resin of Example 5 (liquid phenol resin K) is shown. The measuring method of FIG.2 and FIG.3 is as follows.
Measurement method: 10 ± 0.1 g of a sample was weighed in a container of φ50 mm, the container was cured in an atmosphere of each relative humidity, and the mass increase rate with respect to 100 parts by mass of the sample was measured.

  As can be seen from the measurement results of FIG. 2 and FIG. 3, the mass increase rate of the liquid phenol resin H (Comparative Example 1) using ethylene glycol as the solvent is the liquid phenol resin A (using an ester having a specific boiling range as the solvent). It can be seen that there are many compared to Example 1). Further, a liquid phenol resin D (Example 5) using 50% by mass of an ester having a specific boiling range in 100% by mass of a solvent, and a liquid phenol resin G using 30% by mass of an ester having a specific boiling range in 100% by mass of the solvent. It can be seen that the mass increase rate of (Example 9) is slightly greater than that of Example 1, but less than Comparative Examples 1 and 5. That is, when 100 mass% of the solvent for the liquid phenol resin is used in an amount of 30 mass% or more of an ester having a specific boiling range, moisture absorption is reduced. If the moisture absorption is small, the solvent volatilization temperature does not decrease and the solvent is gradually evaporated, so that the curing of the liquid phenol resin is delayed. For this reason, it is thought that the residual volatile matter after liquid phenol resin hardening decreases, and it becomes difficult to produce foaming.

  Table 3 shows the test results of evaluating the degree of foaming by changing the mass ratio of the ester having a specific boiling point in 100% by mass of the solvent of the liquid phenolic resin. In this test, the same novolak type phenol resin as the liquid phenol resin A is used as the phenol resin, propylene carbonate (boiling point 242 ° C.) is used as the ester having a specific boiling range, and furfuryl alcohol is used as a solvent other than the ester having the specific boiling range. A liquid phenol resin was prepared in which the mass ratio of the resin component and the solvent component was 40:60 (resin: solvent), and the mass ratio of the ester having a specific boiling point in 100% by mass of the solvent was changed. And about each press-fit material obtained by mix | blending 60 mass parts of each liquid phenol resin and 20 mass parts of artificial graphite and 20 mass parts of spherical graphite as a graphite fireproof aggregate, the extent of foaming was evaluated in said way. . The evaluation of the degree of foaming was carried out three times for a press-fitting material having the same mass ratio of esters in a specific boiling range (N = 3), and ◎ (excellent) for all three cases. The case of ◯ (good) was evaluated as ◯ (good), and the case of × (impossible) at any one time was evaluated as x (impossible).

  From Table 3, it can be seen that the foaming phenomenon can be stably suppressed when the mass ratio of the ester in the specific boiling point range in 100 mass% of the solvent of the liquid phenol resin is 30 mass% or more.

Claims (4)

A press-fitting material filled in the gap between the blast furnace walls,
Including graphite fireproof aggregate and liquid phenolic resin consisting of phenolic resin and solvent,
In 100% by mass of the solvent for the liquid phenol resin, the ester having a boiling point of 150 ° C. or more and 350 ° C. or less is contained by 30% by mass or more,
The graphite refractory aggregate is a press-fit material containing 5% by mass or more of spherical graphite in 100% by mass of the graphite refractory aggregate.   The press-fitting material according to claim 1, comprising 50 mass% or more of an ester having a boiling point of 150 ° C or higher and 350 ° C or lower in 100% by mass of the solvent of the liquid phenol resin.   The press-fitting material according to claim 1 or 2, wherein the phenol resin of the liquid phenol resin is a novolac type phenol resin.   The press-fitting material according to claim 1 or 2, wherein the phenol resin of the liquid phenol resin is composed of 60% by mass to 95% by mass of a novolac type phenol resin and 5% by mass to 40% by mass of a resol type phenol resin.