JPS63190021A - Ceramic fiber having low shot content - Google Patents

Abstract

PURPOSE:To provide the titled fiber composed of silica, alumina and vanadium pentoxide, having low shot content in the state of fiber, causing little falling off of shot, giving a blanket, etc., having high heat-insulation and producible in high productivity. CONSTITUTION:A composition 7 composed of silica, alumina and vanadium pentoxide is filled and melted in a vessel 6 having a thin nozzle 5 at the bottom and placed in a furnace 4. The molten composition 7 is extruded by lifting a rod having a sharp conical end with cone angle of 30 deg. and plugging the thin nozzle 5 from above. A rotor 1 is heated at 1,800 deg.C with a heater 3 and rotated at a high speed to fibrillate the composition and obtain the objective ceramic fiber having a shot content of <=10wt.% in the state of fiber.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention uses the centrifugal force of a rotating body rotating at high speed to eject the melt of a fiber composition into fibers, which can be used on the walls, ceilings, etc. of various kilns. Bulk used as high-temperature insulation filler for trolleys, blankets used as high-temperature insulation for lining various industrial furnaces, etc.
Regarding ceramic fibers that can be used for highly heat-resistant textiles used in various applications such as firefighting suits, firefighting cloths, heat-insulating gloves, fire-resistant curtains, heat-resistant work clothes, and heat-resistant aprons, we will explain in more detail that the simitsu content is 10% by weight. The following concerns ceramic fibers with less shot.

(Prior art and its problems) Ordinary ceramic fibers are mainly composed of silica and alumina, with 40 to 52% by weight of silica and 60 to 60% by weight of alumina.
It contains 48% by weight, and most of the fiber diameters in the fiberized state are within the range of l to 3.5 lm, with an average of 2.
In JL111, most of the fiber length is within the range of 1 to 10 cm, the average length is 1 to 3 cm, and 10 to 30% by weight of short fibers of 5 mm or less are included, and the shot content is 1 particle size of 40 ILm. It contains 45 to 55% by weight of the above substances. 3. The seat here is
It refers to a fibrillated non-fibrous cotton fiber composition having an aspect ratio (ratio of major axis to minor axis) of 5 or less and a particle size of 401 Lm or more.

Ordinary bulk ceramic fibers are used as high-temperature insulation fillers for the walls, ceilings, and carts of various kilns, and as blankets for high-temperature insulation inside various industrial furnaces.
In order to include many shots in bulk and blanket,
I! It has poor lrm properties and also has drawbacks such as the shot falling off from the bulk or the blanket and the falling shot damaging parts at the place where it is used. Also, 5m
The strength is weak because there are many short fibers below 21Lm.
It had the disadvantage that the bulk ratio could not be lowered due to the large amount of thin fibers listed below. On the other hand, when ordinary ceramic fibers are used for textile yarn or cloth,
Since there are many short fibers with diameters of less than m, it is difficult to twist the fibers, and since there are many thin fibers with diameters of less than 2 pm, hair clumps (small clumps of entangled fibers) called neps are likely to occur. On the other hand, textile threads or cloth made using ordinary ceramic 111ra alone have low strength and cannot be made to withstand use.

Therefore, in order to impart strength to textile yarn or cloth, 15 to 20 fi amount% of organic fiber is added to ordinary ceramic fiber.
They were mixed to make yarn or cloth.

However, conventional textile yarns and cloth made in this way are
Because ordinary ceramic fibers with a high shot content are used, the yield (the ratio of the amount of yarn obtained to the raw materials used) is poor and expensive, and there is still a large amount of shot that did not fall during spinning. It was heavy due to the inclusion of the powder, and the shot sometimes fell off during use. This dropped shot has the disadvantage of damaging parts where it is used, and it also uses a large amount of organic fiber.
Because it is given strength, it has sufficient strength to withstand use at room temperature, but at high temperatures of 400°C or higher, the organic fibers are fired and the strength becomes extremely low.
It has the disadvantage that it cannot be used in places where vibration resistance, wind speed resistance, and strength are required at high temperatures of 00°C or higher.

Furthermore, when making thin textile yarns or thin textile fabrics, it is necessary to increase the mixing ratio of organic fibers in order to give them enough strength to withstand use. For this reason, textile yarns and cloths containing more than 15 to 20% by weight are rarely used because they have low heat resistance, and those sold in the general market are mostly textile yarns. Textile fabrics called cloths are thick and have a thickness of 1.5 to 2 mm, and are therefore heavy, making them difficult to use for clothing or the like.

(Problems to be Solved by the Invention) The present invention aims to eliminate and improve the drawbacks of the conventional method. In other words, as mentioned above, conventional ceramic fibers have a high shot content, so they are used in various industrial furnaces as bulk fillers and blankets for high-temperature insulation materials such as furnace walls, ceilings, and carts of various kilns. When used as a high-temperature insulation material for lining, the insulation properties deteriorate, and the shot falls off from the bulk or the blanket, and the shot that falls off damages parts where it is used. In addition, there are many short fibers with a length of 5 m or less, and their strength is weak.On the other hand, there are many thin fibers with a length of 2 m or less, so the electrical ratio cannot be lowered.Furthermore, when used in textile yarns or textile fabrics, the short fibers have a weak strength. The large number of fibers makes it difficult to twist, and the large number of thin fibers causes clumps called neps, which weakens the strength. The high content of shot reduces the yield, and the large amount of shot that falls off tends to damage parts at the place of use. On the other hand, with conventional ceramic fibers, 400℃
However, the present invention solves the above-mentioned problems. The purpose is to remove and improve the points.

In order to achieve the above object, the present invention provides a new ceramic fiber that has a small shot content and a large fiber diameter and fiber length in place of the conventional ordinary ceramic fiber.

That is, when the novel ceramic fiber of the present invention is used as a bulk material for high-temperature insulation for the walls, ceilings, and carts of various kilns, or as a blanket for high-temperature insulation for lining the interior of various industrial furnaces, it is possible to The ceramic fiber of the present invention has good insulation properties due to its low ratio, and the shot does not fall off and is less likely to damage parts where it is used.
1 strength should be high because there are few short fibers of m or less.

On the other hand, since there are few thin fibers of 2 ILm or less, the electrical ratio can be lowered.

In other words, the yarn or cloth spun by the novel ceramic fiber of the present invention alone or mixed with other fibers has less short fibers of 5 mm or less at 10% by weight or less than conventional ones, and has a fine fiber of 2 JLm or less. Because there are few fibers, it is easy to twist the fibers, and it is difficult to cause neps, so it has high strength.
Since the fiber contains less shot, the yield is better, and therefore the productivity with the same equipment is higher.The shot content in the textile yarn and cloth is also lower, making the textile yarn and fabric lighter, and the shot content is also higher. Since there is less chance of the parts falling off, there will be less damage to the parts wherever they are used.

Furthermore, since it is not necessary to contain a large amount of organic fiber, the strength decreases less even after the organic fiber is burned at 400° C. or higher. In addition, according to the present invention, strength can be obtained even if the amount of organic fibers is reduced, so even if thin textile yarns or thin textiles are made, the organic content is reduced, and the fibers themselves are light, making them suitable for clothing, etc. It is possible to provide textile yarns and textile fabrics with excellent heat resistance.

(Means for Solving the Problems and Their Effects) According to the present invention, ceramic fibers are made of silica, alumina, and vanadium pentoxide, and the fiber content in the fiberized state is 10% by weight. The purpose of the present invention is to provide a new ceramic fiber with a low shimite content of less than 1.5%.

The invention is characterized in that it is a ceramic fiber consisting essentially of silica, alumina and vanadium pentoxide. Here, "substantially" means that other compositions such as soda, iron oxide, titanium oxide, calcia, and magnesia may be contained in addition to silica, alumina, and vanadium pentoxide. These soda, iron oxide, titanium oxide, calcia, magnesia, etc. are impurities contained in the main raw materials silica, alumina, and vanadium pentoxide, and these impurities reduce the heat resistance of the novel ceramic fiber of the present invention. Therefore, its content is preferably 2% by weight or less.

According to the present invention, silica is 45 to 65% by weight,
Alumina is 53~35% by weight, vanadium pentoxide is 2~2% by weight.
A range of 10% by weight is preferable, especially 52 to 58% by weight of silica, 45 to 40% by weight of alumina, and 2 to 5% by weight of vanadium pentoxide. The best results were obtained in the range of tffi%. When the aluminum content is 53% by weight or more, the fibers tend to break during fiberization due to an increase in surface tension and a decrease in viscous resistance, resulting in an increase in shot content. On the other hand, if the silica content is 65% by weight or more, the viscous resistance becomes too high and the fiber diameter becomes thin. Vanadium pentoxide lowers the surface tension of the molten fiber composition, making it difficult for the fibers to elongate. This has the effect of making it easier to remove the stain, resulting in extremely low stain content, and 2.
If it is less than 10% by weight, the effect will be small, and if it is more than 10% by weight,
Reduces the heat resistance of the novel ceramic fibers of the present invention.

In the present invention, the shot content in the fibrous state is 10% by weight or less, and this new ceramic fiber has
It can be made by the method and apparatus for producing inorganic fabrics previously proposed by the present inventor in Japanese Patent Application No. 61-204805. The mixture is melted or softened, rotated at high speed through a fine hole nozzle (5) provided in the furnace part, and then
) onto a rotating body heated to a temperature higher than the softening temperature of the composition (7), and while maintaining the composition (7) in a thin film state at a uniform melted or softened temperature, centrifugal force is applied to the peripheral edge of the rotating body. It is obtained by "uniformly fluidizing the composition, causing the composition to pop out as the fulcrums (8) at the ends, and forming fibers."

According to the present invention, the average fiber diameter of the ceramic fibers is 2.
5-9 ILm is preferred. At 9 pm or more, the fibers tend to get stuck in the hands, and when used in textiles, the fibers tend to break during spinning, resulting in a decrease in the strength of the yarn or cloth after spinning. On the other hand, when the fiber is less than 2.57 Lm like conventional ceramic fibers, the production amount in fiberization decreases, becomes expensive, and the shot content tends to increase. In addition, there is a tendency for the number of short fibers of 5 mm or less to increase, which weakens the strength of the blanket and lowers the electrical ratio of the bulk to the blanket, making it difficult to produce a low-cost heat insulator. This is because the fibers tend to get tangled during weaving, resulting in the formation of hairs called neps.

According to the present invention, the average fiber length of the ceramic fibers is 3 to 3.
It is preferable to use one with a length of 50 cm. If the length is 3 cm or less, there will be less entanglement of the fibers and the strength of the blanket will be high, and it will be difficult to twist the fibers of textile yarns and textiles, resulting in weak strength. On the other hand, if the average fiber length of ceramic fibers is 50 cm or more, it is too long.
The disadvantage is that the fibers are too entangled at the time of fiberization, making it difficult to collect the fibers. Therefore, the average fiber length of ceramic fibers is 3
Good results can be obtained with a length of ~50 cm.

However, depending on the spinning machine, fibers of 5 cm or more may be too long, and the best results are obtained with fibers cut into 3 to 5 cm. In addition, short fibers of 5 mm or less are conventionally 1
Although it was found to be 0 to 30% by weight, it is preferable to use 10% by weight or less. End fibers of 5 mm or less have very little fiber entanglement, so the handling strength, wind speed, and vibration resistance of the blanket are reduced. As the insulation becomes weaker, it becomes difficult to use bulk and blankets as fillers for high-temperature insulation or as various types of inner high-temperature insulation materials to create insulation materials with a low electric ratio, light weight, and low unit cost. Also, when the fibers are twisted,
It is difficult to obtain the effect of increasing the strength of textile yarns and cloth, and the fibers tend to scatter, resulting in poor yield.

(Example) Next, the most typical example of the present invention will be described with reference to the drawings.

Example 1 A composition (7) containing 56% by weight of silica, 40% by weight of alumina and 4% by weight of vanadium pentoxide was prepared in advance at the bottom.
．． In a molybdenum container with a pore nozzle with a diameter of 5 mm, the temperature was raised to 1800°C by heating with thermal radiation from a W heater.
After softening to a viscosity of 2 voids, a pointed rod with a 30" conical tip inserted from the upper center of the fine hole nozzle was raised to elute at a rate of 500 g per minute, and the rotating body The molybdenum rotating body (1) was heated to 1800℃ by thermal radiation from the W heater fixed at the bottom of the
When the rotating body (1) with a diameter of 200φ was rotated at a high speed of 00 rpm to perform fiberization, most of the fiber diameters were 4 to 4.
6 gm, with an average of 5 body m and most of the fiber lengths in the range of 15-25 cm, with an average of 20 cm, 4
It was possible to form a new ceramic fiber with a shot content of 5% above 0ILm.

The new ceramic fiber obtained in this way has 14
A surface treatment agent of 1% by weight propylene oxide-ethylene oxide copolymer aqueous solution was sprayed at a ratio of 1% by weight, the cotton was collected, needled with 96 strokes of an LC trowel, and fired at 700°C. The surface treatment agent was burnt, and a plunget having a thickness of 25 mm, @600 mm, and a bulk specific gravity of 0.13 was prepared. The tensile strength at room temperature and thermal conductivity at room temperature and 1000° C. of the blanket thus obtained were examined and the results are shown in Table 2.

(Hereinafter in the margin) Table 1 (Hereinafter in the margin) Table 2 Table 3 East Created accordingly. The average fiber diameter, average fiber length, fiber length content of 5ffln1 or less, shot content, and bulk specific gravity of the novel ceramic fibers are as shown in Table 1.

The tensile strength at room temperature and thermal conductivity at room temperature and 1000° C. of the blanket thus obtained were examined and the results are shown in Table 2.

Comparative Example 1 A conventional blanket was prepared in the same manner as in Example 1.2, except for the bulk specific gravity of the blanket obtained by using ordinary ceramic fibers. In addition, the average fiber diameter of the ordinary ceramic fiber,
The average fiber length, fiber length content of 5 mm or less, shot content, and bulk specific gravity are as shown in Table 1.

The tensile temperature at room temperature and thermal conductivity at room temperature and 1000''C of the blanket thus obtained were examined and the results are shown in Table 2.

Example 3 A novel ceramic fiber of the present invention obtained in the same manner as in Example 1.2 above! 1190% by weight and 10% rayon fiber
% by weight, and use a spinner to make a diameter of 0.7 mm (7)
A yarn was prepared, and after heating at room temperature and 1000'C for 2 hours, the tensile strength and yield were determined as shown in Table 3.

Comparative Example 2 90% by weight of the same ordinary ceramic fiber as in Comparative Example 1 and 110% by weight of rayon 1lJ were mixed to create a thread with a diameter of 0.7 mm using a spinning machine, and the tensile strength after heating at room temperature and 100°C for 2 hours was The strength and yield were determined and were as shown in Table 3.

Example 4 The novel ceramic fiber of the present invention @100% by weight obtained in the same manner as in Example 1.2.3 above was used to create a thread with a diameter of 0.7 mm and kept at room temperature.

The tensile strength and yield after heating at 1000° C. for 2 hours were determined and were as shown in Table 3.

(Effects of the Invention) As described above, according to the present invention, the ceramic fiber is made essentially of silica, alumina, and vanadium pentoxide, and the shot content in the fiberized state is 10% by weight or less. It has been found that this ceramic fiber has the following excellent effects.

(1) It became possible to make lightweight blankets, textiles, and textiles with a low shot content.

(2) It has become possible to produce bulk products, blankets, textile yarns, and textile fabrics with less shot dropout.

(3) Bulks and blankets with low thermal conductivity and good thermal properties have become available.

(4) Textile yarns and textiles with less organic fibers can now be produced.

(5) The yield was improved and the productivity with the same equipment was increased.

[Brief explanation of the drawing]

FIG. 1 is an example of a schematic cross-sectional view of an apparatus for producing novel ceramic fibers used in the present invention. Explanation of symbols 1... High-speed rotating body, 2... - Rotating shaft, 3... Heater, 4... Furnace, 5... Pore nozzle, 6... Heating container, 7... Heating Composition softened by 8...Fiber fulcrum, 9.-11J! . that's all

Claims (1)

[Scope of Claims] 1) Ceramic fibers consisting essentially of silica, alumina, and vanadium pentoxide, characterized in that the shot content in the fiberized state is 10% by weight or less. ceramic fiber. 2) The composition ratio of silica and alumina is silica 45~
65% by weight of alumina, 53-35% by weight of alumina, and 2-10% by weight of vanadium pentoxide. 3) The average fiber diameter of the ceramic fiber is 2.5 to 9μ
The ceramic fiber with less shot according to claim 1, characterized in that the fiber is m. 4) The average fiber length of the ceramic fibers is 3 to 50 cm.
The shot-reducing ceramic fiber according to claim 1, characterized in that: 5) The shot-reduced ceramic fiber according to claim 1, wherein the ceramic fiber contains 10% by weight or less of ceramic fibers having a fiber length of 5 mm or less.