JPH0336788B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is mainly concerned with a consumable immersion probe for measuring the temperature in molten iron and molten steel in blast furnaces, open hearth furnaces, and converters, as well as measuring dissolved oxygen content, carbon content, etc., and sampling. This invention relates to a ceramic fiber sleeve used in a heat-resistant protection tube and a method for manufacturing the same. [Conventional technology] In recent years, in order to rationalize the iron and steel manufacturing field and improve quality control, for example, converter furnaces, electric furnaces,
In the casting process, temperature is measured using a consumable thermocouple, which is a rapid immersion thermocouple method, for the purpose of temperature control, and in the converter and casting processes, carbon Consumable multi-purpose measuring elements (supplements, etc.) are used for measuring oxygen content and sampling, etc., and play an extremely important role in quality control and operation. This consumable thermocouple and consumable multipurpose measuring element,
The so-called consumable type immersion probe is equipped with a heat-resistant protection tube for the purpose of preventing thermal deterioration and improving corrosion resistance in the part that is immersed in molten steel or molten iron.Asbestos sleeves and ceramic fiber sleeves are used as heat-resistant protection tubes. etc. are used. However, these expendable immersion probes equipped with heat-resistant protection tubes cause many problems when immersed in molten steel or molten iron, and have never reached a satisfactory state. In other words, when a sleeve containing asbestos as the main component is used as a heat-resistant protective tube, although it is inexpensive, its heat resistance and corrosion resistance are extremely low, so it disappears during immersion, and a probe equipped with an asbestos sleeve is During immersion, the molten steel or molten iron may be burnt out and splash may occur, or when the molten steel or molten iron is pulled up, only the immersed portion may remain in the molten steel or molten iron and remain as an impurity. Also, contamination of the working environment due to the use of asbestos,
In other words, it can cause asbestos pollution,
Its use is becoming severely restricted. On the other hand, sleeves mainly composed of ceramic fibers can be broadly classified into (a) a product obtained by vacuum suction molding from an aqueous slurry containing defibrated ceramic fibers and a binder and drying, followed by an inorganic binder. There are two types of sleeves: (b) sleeves that are impregnated and hardened, and (b) sleeves that are wound in multiple layers with a paper-like material mainly composed of ceramic fibers and hardened with an inorganic binder. Although it is an inorganic fiber with higher heat resistance than that of inorganic fibers, it does not have sufficient density necessary for corrosion resistance, and binders are added to further increase the density.
There were cases in which significant unevenness occurred in the degree of hardening treatment by the coating material. In other words, during the curing process in which the sleeve obtained by suction molding and drying is impregnated with a colloidal binder (for example, silica sol), there may be uncured areas due to uneven impregnation, and when the colloidal binder is dried, colloidal particles may be formed. Due to the movement of the material, a phenomenon occurred in which only the surface part could be cured, and the inside part could hardly be cured. As a result, there were variations in durability and the product could only be used for a short period of time. Furthermore, it has been difficult to obtain a sleeve with desired precision due to deformation that occurs when the sleeve is released from the mold after vacuum suction molding. On the other hand, in the latter case (b), hardening can be done at the stage of winding in multiple layers, so there is no significant unevenness in the hardening, but it is necessary to have sufficient erosion resistance, especially against the slag that comes into contact with it during dipping. In addition to lacking in density, the ceramic fiber is first formed into a paper shape and then molded into a cylindrical shape, making it extremely expensive and unsuitable for use as a consumable item.Like the former, it is by no means satisfactory. Ta. Conventional expendable immersion probes equipped with heat-resistant protection tubes made of fibrous sleeves have insufficient corrosion resistance against molten iron, molten steel, and slag, or cannot be used stably, or are equipped with asbestos sleeves. It has been reported that the probes used in this study caused a deterioration of the working environment due to asbestos dust, and that the expendable immersion probe equipped with a ceramic fiber multilayer sleeve was unsuitable for use as a consumable item because the sleeve was too expensive. It had various problems that should be improved. On the other hand, according to Japanese Patent Publication No. 54-16536, artificial mineral fibers with a fiber length of 2 mm or less, a binder,
An extrusion molded product made from a composition to which water, fillers, additives, auxiliary agents, and a viscosity agent as a fiber breakage modifier are added, and the main component of the molded product is artificial fiber and has a bulk specific gravity of 0.5 or more. An artificial mineral fiber extrudate and a method for manufacturing the same are disclosed. In addition, artificial mineral short fibers such as rock wool and class wool are used as artificial mineral fibers, organic binders such as phenol, melamine, urea resin, and rubber binders are used as binders, and inorganic binders such as cement, water glass, and gypsum are used as binders. As fillers, Shirasu balloon, perlite pumice, vermiculite, diatomaceous earth, kaolin, bentonite, various clays; as additives and auxiliaries, water repellents such as wax, silicone resin, water resistance improvers,
Carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, sodium alginate, starch, vegetable rubber, colloidal asbestos, apalgite, as a viscosity agent for controlling fiber breakage.
It is also described that synthetic resins and vegetable mucilages can be used. However, the artificial mineral fiber extrusion molded article disclosed in the above-mentioned publication is lightweight, has excellent processability, fire resistance, and is intended for construction materials such as interior materials, exterior materials, and ceiling materials, which have high strength. Due to the heat resistance of the man-made mineral fibers used in construction materials such as rock wool and glass wool, which are the main constituent materials, the man-made mineral fiber extrusion molded body is made of molten iron that is in contact with the heat-resistant protective tube of the consumable immersion probe that is the object of the present invention. It cannot withstand high temperatures like molten steel. Furthermore, in order to improve the workability and strength of the artificial mineral extrusion molded body as a building material, the artificial mineral fibers are adjusted to 2 mm or less and uniformly dispersed,
Increases the chances that fibers overlap and intersect,
It is characterized by a structure in which the intersection points are joined with a binder, but the handling work required for the heat-resistant protection tube of the consumable immersion probe, which is the object of the present invention, is the impact resistance when dropping it on the floor etc., and the molten iron. , heat spalling resistance when immersed in molten metal such as molten steel, molten iron,
The above structure has a rather serious drawback in terms of heat insulation properties when immersed in high-temperature molten metal such as molten steel. [Problems to be solved by the present invention] The present invention aims to improve the heat resistance of the asbestos sleeve used as the heat-resistant protective tube, and to improve the durability and corrosion resistance of the sleeve whose main component is ceramic fiber. In order to improve the quality and reduce costs, we also
By improving the impact resistance, heat spalling resistance, and heat insulation properties of the molded product described in the artificial mineral fiber extrusion molded product and its manufacturing method described in No.
Extrusion to obtain extremely inexpensive ceramic fiber sleeves that have excellent heat insulation properties and corrosion resistance when immersed in molten iron and molten steel, can be used stably, and have excellent impact resistance when handled. The object of the present invention is to provide a molding composition and a method for producing the same. [Means for Solving the Problems] The present invention mainly relates to the immersion part of a expendable immersion probe such as a expendable thermocouple and a sublance that measure the temperature in molten iron and molten steel, and furthermore, measure dissolved oxygen, carbon content, etc. Contains 60-93% by weight of ceramic fiber and 5-5% clay for the heat-resistant sleeve attached to the outside.
35% by weight and 2 to 10% by weight of an organic binder, with the addition of fillers, inorganic binders, organic molding aids, etc. as necessary, and a total water content of 40% by weight per 100 parts by weight of the compound. A ceramic fiber composition for extrusion molding prepared by adding water to a concentration of ~140 parts by weight, wherein the ceramic fiber is in the form of granules in which the fibers are entangled with fibers having a length of 3 mm or more in a defibrated state. material, and its surface is made of liquid paraffin.
It is characterized by being coated with one or more fiber smoothing agents selected from a stearylamine lactate-fatty-linked diethanolamine emulsion mixture, a polyoxyethylene polyoxypropylene block copolymer, and a polyoxyethylene stearyl aminopropylamine lactic acid. The present invention provides a ceramic fibrous composition for extrusion molding and a method for producing the same. Next, the ceramic fibrous composition for extrusion molding of an extrusion molded article of the present invention will be explained in detail. The ceramic fiber composition for extrusion molding of the present invention contains 60 to 93% by weight of ceramic fibers and 5 to 35% by weight of clay.
and 2 to 10% by weight of an organic binder consisting of one or more of phenolic resin, polyacrylic resin, vinyl acetate resin, polyethylene oxide resin, and methyl cellulose, and filler and inorganic binder as necessary. This is a composition for extrusion molding, to which an organic molding aid and the like are added. The ceramic fiber used in the present invention has heat resistance,
In order to have excellent heat insulation and impact resistance,
The main material is silica/alumina ceramic fiber, but if particularly high heat resistance is required, part or all of the ceramic fiber may be replaced with alumina crystal fiber, mullite crystal fiber, etc. . Molten iron,
Especially preferred is silica-alumina ceramic fiber, which has sufficient durability for short-term immersion in molten steel and slag and is inexpensive. The content of ceramic fiber, which is the main material, is 60 to 93.
The reason why it is limited to a range of 60% by weight is that if it is less than 60% by weight, it will not be possible to obtain a product with excellent heat insulation and impact resistance, whereas if it exceeds 93% by weight, the handling strength and hot strength will be reduced. It's because it's too much. In addition, as a fiber smoothing agent for coating the surface of ceramic fibers,
It is sufficient to impregnate 0.1 to 1.0 weight, and the impregnation method may be by spraying during fiberization or by impregnating and drying the resulting fiber. Typical fiber smoothing agents include liquid paraffin and alkylamino oxy acid salts, alkylaminoalkyl amine oxy acid salts, polyoxyethylene alkylamino oxy acid salts, polyoxyethylene alkylaminoalkyl amine oxy acid salts, polyoxyethylene alkyl An emulsified mixture with one or more selected from amino ethers, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, alkylolamides, and polyoxyethylene polyoxypropylene block copolymers, or monoglyceride compounds. and alkylamino oxy-acid, alkylaminoalkyl amine oxy-acid, polyoxyethylene alkylaminoalkyl amine oxy-acid, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, alkylolamide, polyoxyethylene polyoxypropylene ester Emulsified mixture with any one or two or more copolymers, or alkylaminooxyacid, alkylaminoalkylamine oxyacid, polyoxyethylenealkylaminooxyacid, polyoxyethylenealkylaminoalkylamine oxyacid , polyoxyethylene alkylamino ether, polyoxyethylene alkylamino ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid salt group ester, alkylolamide,
There is one or more fiber treatment agents selected from polyoxyethylene polyoxypropylene block copolymers. Preferred examples include emulsified mixtures of liquid paraffin-stearylamine lactate and aliphatic diethanolamine, polyoxyethylene stearyl aminopropyl amine lactate, and polyoxyethylene polyoxypropylene blot copolymers. Further, the clay used in the present invention may be any clay that has binding strength, plasticity, and fire resistance, such as montmorillonite, hectorite, bentonite, acid clay, kaolin, and Kibushi clay. Particularly preferred are montmorillonite and hectorite, which have the plasticity to impart shape retention to the molded product during molding, and the bonding strength necessary to obtain handling strength and hot strength in small amounts. The reason why the amount of clay added is limited to 5 to 35% by weight is that if it is less than 5% by weight, sufficient handling strength and hot strength will be low;
This is because if the content exceeds % by weight, the handling strength and hot strength will be sufficiently high, but the heat spalling resistance and heat insulation properties will decrease. Further, as the organic binder used in the present invention, any one selected from thermosetting phenolic resins, thermoplastic polyacrylic resins, vinyl acetate resins, polyethylene oxide resins, methyl cellulose of water-soluble cellulose ether, etc. It is preferable that it is one species or two or more species. The reason why the amount of the organic binder added is limited to 2 to 10% by weight is that if it is less than 2% by weight, the strength and impact resistance at room temperature will decrease, and the handleability will deteriorate as well as the surface finish will deteriorate. On the other hand, if it exceeds 10% by weight, smoke or splash will be generated when immersed in molten steel or molten iron, resulting in a deterioration of the working environment. In addition, the fillers used in the present invention include refractory powders such as alumina, mullite, and siyamoto, magnesia, chromium oxide, magnesia chromium spinel,
A powder such as silicon carbide is selected. As the inorganic binder, general heat-resistant inorganic binders such as colloidal silica, colloidal alumina, aluminum phosphate, and ammonium phosphate are suitably selected for the purpose of increasing handling strength and hot strength. As the organic molding aid, starch, sodium alginate, gum arabic, gelatin, molasses, pulp waste liquid, etc. used in general extrusion molding methods are preferably selected. In the ceramic fibrous composition for extrusion molding of the present invention, most of the ceramic fibers are defibrated and uniformly dispersed in a composition mainly composed of the clay and the organic binder, and the remainder is It is a granular material, and has a structure in which the granular material is surrounded by a composition in which the salamic fibers are uniformly dispersed. The fiber length of the ceramic fibers uniformly dispersed in the defibrated state in the composition mainly composed of the clay and the organic binder is preferably 3 mm or more. The ceramic fibers, which are uniformly dispersed in the defibrated state, increase the strength of the ceramic fibrous sleeve due to the fiber-reinforcing action of the composition mainly composed of clay and an organic binder, and also improve impact resistance at room temperature and resistance to high temperatures. This has the effect of significantly increasing heat spalling resistance. In particular, when the fiber length of the ceramic fiber is 3 mm or more, the impact resistance and heat spalling resistance of the ceramic fiber sleeve are further improved. Some of the ceramic fibers exist in the form of granules, and in particular, the size and shape of the granules are flat or elliptical, with a length in the major axis direction of 5 mm or less and a length in the minor axis direction of 3 mm or less. It is preferable that The ceramic fiber granules are coated with a composition primarily consisting of clay and an organic binder in which a portion of the ceramic fibers are uniformly dispersed. Ceramic fiber particles are coated with a highly heat-resistant and corrosion-resistant composition, so when using a ceramic fiber sleeve as a heat-resistant protection tube for a consumable immersion probe, there is no direct contact with high-temperature molten metal; Since the ceramic fiber sleeve itself maintains numerous fine voids, it significantly improves the high-temperature durability and heat insulation properties of the ceramic fiber sleeve. In particular, by regulating the size and shape of the ceramic fiber particles as described above, it is possible to maintain high heat resistance and heat insulation properties of the ceramic fiber sleeve, while simultaneously significantly increasing strength, impact resistance, and heat spalling resistance. Can be done. The ceramic fiber composition for extrusion molding of the present invention has a bulk density of 0.5 to 1.2 g/cm ³ . The reason why the bulk density of the ceramic fiber sleeve is limited to a range of 0.5 to 1.2 g/cm ³ is that if the bulk density is less than 0.5 g/cm ³ , even if the constituent material has excellent erosion resistance, the pores Because the rate increases, when immersed in molten iron, etc.
It is easy for molten iron, molten steel, slag, etc. to invade, resulting in rapid erosion. On the other hand, if the bulk density exceeds 1.2 g/ ^cm3 , the corrosion resistance against molten iron, molten steel, and slag will be improved, but the insulation required to protect the paper sleeve that houses various measurements or functions inside the consumable probe will increase. This is because not only the properties but also the heat spalling resistance and the impact resistance deteriorate, and the range is preferably 0.6 to 0.9 g/cm ³ . As described above, the ceramic fiber composition for extrusion molding of the present invention has a unique structure, which is different from conventional asbestos sleeves and ceramic fiber sleeves, so it is suitable for use as a heat-resistant protective tube for expendable immersion probes. It can be used for ceramic fiber sleeves for extrusion molding, etc., which exhibit excellent performance under harsh conditions. In addition, there is a large difference in the heat resistance of the artificial mineral fiber, which is the main constituent material, from the artificial mineral fiber extrusion molded article disclosed in Japanese Patent Publication No. 54-16536, and furthermore, the fiber arrangement structure of the molded article is different. Due to this fundamental difference, the ceramic fiber sleeve of the present invention exhibits extremely excellent performance under the above-mentioned severe conditions, which is not seen in the above-mentioned artificial mineral fiber extrusion molded product. Next, the method for producing the ceramic fibrous composition for extrusion molding of the present invention will be specifically explained. The ceramic fiber composition for extrusion molding of the present invention is
Ceramic fibers consisting of fibers with a length of 3 mm or more in the defibrated state and granules in which the fibers are entangled, and the fiber surface is made of a liquid paraffin-stearylamine lactate-aliphatic diethanolamine emulsion mixture, polyoxyethylene. Ceramic fibers are made from bulk ceramic fibers coated with one or more fiber smoothing agents of stearyl aminopropylamine lactate and polyoxyethylene polyoxypropylene block polymers into chips of 5 to 10 mm. 60-93% by weight, 5% clay
~35% by weight and 2 to 10% by weight of an organic binder as a solid substance consisting of one or more types selected from phenol fat, polyacrylic resin, vinyl acetate resin, polyethylene oxide resin, and methyl cellulose, and Water is added so that the total water content is 40 to 140 parts by weight to 100 parts by weight of a compounded composition consisting of fillers, inorganic binders, organic molding aids, etc. added as necessary, and kneaded. You can make it. Bulk ceramic fibers are used, and the proportions of clay, organic binder, additional filler, inorganic binder, organic binder, organic forming aid, and other auxiliary materials and water are within the above-mentioned ratios. The mixture is mixed in a blade-type kneading machine such as a kneader, cutter mixer, paddle mixer, or all-purpose mixer to homogenize the composition mainly consisting of clay and an organic binder, and at the same time to form bulk ceramic fibers. A part of the clay is granulated and most of it is defibrated to uniformly disperse it in a composition mainly consisting of the clay and an organic binder to form a kneaded material with appropriate plasticity. In addition, as ceramic fibers, bulk or pine-like ceramic fibers can be cut in advance using a cutter mill, a feather mill, etc., which are a type of impact crusher.
The ceramic fibers, clay, organic binder, additional filler, inorganic binder, organic binder, organic forming aid, and other auxiliary materials and water are mixed in the above-mentioned ratio range by forming them into chips using a shear mill or the like. By kneading the blended mixture in the same manner as described above, defibration, granulation, and uniform dispersion of ceramic fibers become easy, and a kneaded product having appropriate plasticity can be obtained. In particular, by using ceramic fibers coated with a fiber smoothing agent, it is easier to defibrate the ceramic fibers during kneading, suppress fiber breakage, and enable more uniform dispersion. It is ideal for controlling the length of defibrated ceramic fibers of the sleeve obtained by drying to 3 mm or more. Furthermore, bulk or matte ceramic fibers coated with a fiber smoothing agent are cut in advance by cutting, shearing mill, etc. to a size of 5 to 10 mm.
mm chips and pear, the chip-like ceramic fibers, clay, organic binder, additional fillers, inorganic binders, organic binders, organic molding aids and other auxiliary materials and water in the above-mentioned ratio range. By kneading the blended mixture in the same manner as described above, a kneaded product having a more preferable arrangement structure of ceramic fibers and appropriate plasticity can be obtained. In particular, the kneaded material is extruded and dried to form a sleeve in which the length of the defibrated ceramic fibers is 3 mm or more, the length of the granules in the long axis direction is 5 mm or less, and the length in the short axis direction is 3 mm or more. Ideal for adjusting the height to 3mm or less. Total water content based on 100 parts by weight of the solid content of a blended composition consisting of ceramic fibers, clay, organic binders, and auxiliary materials such as additional fillers, inorganic binders, organic binders, and organic molding aids. The reason why is limited to 40 to 140 parts by weight is that if it is less than 40 parts by weight, the fluidity of the kneaded composition used for molding will decrease, making it difficult to continuously extrude hollow pipes during molding.
On the other hand, if it exceeds 140 parts by weight, the shape retention of the kneaded composition used for molding decreases, making it difficult to extrude hollow pipes continuously during molding, and causing problems such as only water being squeezed out from the circular nozzle outlet of the molding machine. It is from. For this reason, the total water content is 40 to 140.
It should be within the range of parts by weight, but the preferred range is
It is 80-110 parts by weight. As mentioned above, a circular nozzle in which a circular medium ball is arranged concentrically forms a kneaded material having plasticity, which is obtained by mixing and kneading ceramic fibers, clay, an organic binder, additional auxiliary materials, and water within a predetermined range. The pipe is continuously formed into a hollow pipe using an extrusion molding machine having an extruder at the tip, and then dried using a commonly known dryer such as an electric dryer, a microwave dryer, or a kerosene-burning dryer. [Examples] Examples of the present invention will be described below along with comparative examples. Example 1 A silica-alumina ceramic fiber (trade name: Ibiwool) to which 0.3% by weight of polyoxyethylene/polyoxypropylene block copolymer was attached was cut into chips with a fiber length of 10 mm or more using a cutter mill, which is a type of impact crusher. I prepared a shape. The obtained ceramic fiber, montmorillonite, methylcellulose, and vinyl acetate resin were blended in the weight percentages shown in Table 1, and kneaded for 10 minutes in a mixer, which is a type of blade-type kneader. The average fiber length of the defibrated ceramic fibers in the resulting kneaded product was 4.8 mm. The granules had an elliptical shape with a major axis of 4.5 mm and a minor axis of 2 mm. Next, this kneaded material was extruded at a speed of 0.5 using an extrusion molding machine having an extrusion nozzle in which a circular medium ball with an outer diameter of 25 mm was arranged concentrically inside a circular nozzle with an inner diameter of 35 mm.
A cylindrical sleeve was formed at a speed of m/min, cut into 30 cm lengths, and dried at 110° C. for 6 hours in an electric hot air dryer. The quality of the obtained molded sleeve was as shown in the table below, and its structure was as shown in FIG. According to this, the average length of the defibrated ceramic fibers was 3.5 mm, and the average length of the granular ceramic fibers was 3.5 mm for the long axis and 1.8 mm for the short axis. In addition, this sleeve was immersed in molten steel containing basic slag held at 1700°C for 30 seconds, and its appearance was observed, and the results are shown in the table below. Example 2 Ceramic fibers obtained in the same manner as in Example 1, hectorite, phenol resin, and vinyl acetate resin were blended into the composition shown in Table 1, and the sleeve of the present invention was obtained by the same manufacturing method as in Example 1. Ta. The quality of the molded sleeves obtained and the test results are shown in the table below. Example 3 80% of the ceramic fiber obtained in the same manner as in Example 1 was pre-impregnated with a fiber smoothing agent solution and dried.
Ceramic fiber was prepared by mixing 20% of alumina crystalline fiber with a deposition rate of 1% by weight. The mixtures were mixed at the proportions shown in the table below and kneaded for 5 minutes using a kneader with a sigma blade. A sleeve of the present invention was obtained using the same molding method as in Example 1. The quality of the molded sleeves obtained and the test results are shown in the table below. Example 4 Ceramic fibers obtained in the same manner as in Example 1, montmorillonite, and polyethylene oxide were
A sleeve of the present invention was obtained by blending the compositions shown in the table and following the same procedure as in Example 1. The quality of the molded sleeves obtained and the test results are shown in the table below. Comparative Example 1 Untreated silica-alumina ceramic fiber and
A slurry was prepared using colloidal silica and a polyacrylamide flocculant in the composition shown in Table 2, and a mold with an outer diameter of 25 mmφ and a length of 300 mm was coated with gold, and a molded sleeve with a thickness of 5 mm was formed using a vacuum forming method. I got it. The bulk density at this time was 0.3 g/cm ³ .
The dried molded sleeve was further impregnated with a colloidal silica solution and dried to obtain a molded sleeve having a bulk density of 0.5 g/cm ³ . The quality of the molded sleeves obtained and the test results are shown in the table below. Comparative Example 2 Untreated silica-alumina ceramic fibers were pressed for 5 minutes at a pressure of 100 kg/cm ² using a dry press to reduce the fiber length to 2 mm or less, and then molded using the same formulation and process as in Example 1. did. The quality and test results of the molded sleeves obtained are shown in the table below. Also, the average length of defibrated ceramic fibers is
It was 1.1mm. Comparative Example 3 A slurry was prepared by adding untreated silica/alumina ceramic fibers, acrylonitrile butadiene latex as a binder, and sulfuric acid as a coagulant, and the slurry was made into a slurry using a circular mesh continuous paper machine.
Form a 0.5mm paper, and after drying, while impregnating it with colloidal silica solution, make it into a length with an outer diameter of 25mmφ.
It was wound around a 300 mm cylinder until the outer diameter was 35 mmφ, and after drying, a molded sleeve with a bulk density of 0.55 g/cm ³ was obtained. The quality and test results of the molded sleeves obtained are shown in the table below. Comparative Example 4 A molded sleeve was obtained using the same formulation and manufacturing method as in Example 1 using silica-alumina ceramic fibers that had not been treated with a fiber smoothing agent. The quality of the obtained molded sleeve is as shown in the table below.
Its structure was as shown in Figure 2. Comparative Example 5 Same formulation and production as in Example 1 using silica-alumina ceramic fibers (average fiber length 60 mm) to which 0.3% by weight of a mixture of liquid paraffin, stearinamine lactate and aliphatic diethanolamine was attached. A molded sleeve was obtained by the method.
The quality and test results of the molded sleeve obtained were as shown in the table below. The average length of defibrated ceramic fibers is 2.5
It's hot in mm. Example 5 The chip-shaped ceramic fiber obtained in Example 1, hectorite, fine alumina powder, starch, and methyl cellulose were blended in the weight percentages shown in Table 1, and the sleeve of the present invention was manufactured by the same manufacturing method as in Example 1. I got it. The quality and test results of the molded sleeves obtained are shown in the table below. Example 6 The chip-shaped ceramic fiber obtained in Example 1, montmorillonite, colloidal alumina, sodium alginate, and phenolic resin were blended in the weight percentages shown in Table 1, and the present invention was produced using the same manufacturing method as Example 1. Got the sleeve. The quality and test results of the molded sleeves obtained are shown in the table below. [Effects of the Invention] The ceramic fibrous sleeve using the composition of the present invention thus obtained is structurally similar to the conventional ceramic fibrous molded product as described in detail, and therefore has a similar structure to the slag. The consumable immersion probe equipped with the ceramic fiber sleeve has excellent corrosion resistance against molten iron and molten steel, as well as comparable impact resistance during handling, making it ideal as a sensor. do. Further, compared to ceramic fibrous sleeves made using the composition of the present invention and ceramic fibrous sleeves made by conventional wet suction molding, molded products with no variation in composition and density and good dimensional accuracy can be obtained. In addition, because we were able to uniformly disperse the ceramic fiber length, which could not be achieved with conventional extrusion molding methods, the impact resistance was improved by about twice as much, which is sufficient to withstand impacts during transportation and assembly. Now I can deal with it.

【table】

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 shows a sectional view of a ceramic fibrous sleeve using the composition of the present invention, and FIG. 2 shows a sectional view of a ceramic fibrous sleeve obtained in Comparative Example 4. 1... Granular ceramic fiber, 2... Spread ceramic fiber.

Claims (1)

[Claims] 1. Consisting of 60-93% by weight of ceramic fiber, 5-35% by weight of clay, and 2-10% by weight of an organic binder, and optionally fillers, inorganic binders, organic molding aids, etc. A ceramic fiber composition for extrusion molding, in which water is added to 100 parts by weight of the composition to have a total water content of 40 to 140 parts by weight, wherein the ceramic fiber is defibrated. It is a granular material in which fibers are entangled with each other with a length of 3 mm or more, and the surface thereof is a liquid paraffin-stearylamine lactate-aliphatic diethanolamine emulsion mixture, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxypropylene block copolymer, A ceramic fibrous composition for extrusion molding, characterized in that it is coated with one or more fiber smoothing agents selected from oxyethylene stearyl aminopropylamine lactate. 2. Claim 1, wherein the ceramic fiber is an alumina-silica ceramic fiber, a crystalline alumina fiber, or a crystalline mullite fiber.
Ceramic fibrous composition for extrusion molding as described in 2. 3. The ceramic fibrous composition for extrusion molding according to claims 1 to 2, wherein the clay is one or two selected from montmorillonite and hectorite. 4. Ceramic fiber material for extrusion molding according to claims 1 and 2, wherein the organic binder is one or more selected from phenolic resin, vinyl acetate resin, polyethylene oxide resin, and methyl cellulose. Composition. 5 Ceramic fibers consisting of fibers with a length of 3 mm or more in the defibrated state and granules in which the fibers are entangled, and the fiber surface is composed of a liquid paraffin-stearylamine lactate-aliphatic diethanolamine emulsion mixture, polyoxy Ceramic fiber made from bulk ceramic fiber coated with one or more fiber smoothing agents of ethylene stearyl aminopropylamine lactate and polyoxyethylene polyoxypropylene block copolymer into chips of 5 to 10 mm. 60 to 93% by weight of clay, 5 to 35% by weight of clay, and an organic binder consisting of one or more selected from phenol fat, polyacrylic resin, vinyl acetate resin, polyethylene oxide resin, and methylcellulose. The total moisture content is 40 to 140 parts by weight based on 100 parts by weight of the compounded composition, which contains 2 to 10% by weight as solids, and fillers, inorganic binders, organic molding aids, etc. added as necessary. Add water until
A method for producing a ceramic fibrous composition for extrusion, characterized in that it is kneaded. 6. Ceramic fiber composition for extrusion according to claim 5, wherein the ceramic fiber is any one or two of alumina-silica ceramic fiber, crystalline alumina fiber, and crystalline mullite fiber. How things are manufactured.