JPS6385152A - Production of inorganic fiber molded body - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a material with tensile strength suitable for fire-resistant insulation materials provided inside industrial IJD heat furnaces, etc., which are widely used in ajlls, black bars, chemical plants, etc. This is a method for producing high-quality, high-category inorganic fiber molds.

[Conventional technology]

Industrial DO heat furnace #Alumina 40-60JFi as a material
Molded bodies of amorphous ceramic fibers containing n% (μ% and M5) and 40 to 60% silica and having a bulkiness of 0.09 or more have been widely used. However, the maximum operating temperature of these ceramic fiber molded bodies is 1200°C, and in order to be compatible with industrial heating furnaces used at even higher temperatures, in recent years so-called crystalline alumina fibers containing 70 to 90% alumina and 5 to 50% silica have been developed. was developed.

However, since crystalline alumina fibers have lower strength than amorphous ceramic fibers, it is necessary to form the ceramic fibers to a bulk density of 0.09 μm, so a needle punch method has been adopted. However, in the needle punch method, single fibers tend to break into pieces, making it difficult to obtain a molded product with high strength.

For this reason, crystalline alumina fibers are prepared by first opening the alumina fibers in water, then hardening them with an organic glue such as cornstarch and an inorganic binder special for silica sol, and forming them into a felt shape, which has a bulkiness of 0.09. The above bottom body was manufactured. However, in this method, the length of each fiber is cut into several lengths during molding, so there is less entanglement between the fibers, and the tensile strength of dk, which has been burned out at high temperatures, is 50 to 100 g#. In addition to this, the production cost was also high because it was a wet process.

On the other hand, as an experiment to use it in its original long state, a method of obtaining a mat by needle-punching alumina foam bodies using an organic non-woven fabric as a reinforcing agent (JP-A-60-1104!+9 Newsletter) ) has been proposed, but the phenomenon of alumina fibers shattering into pieces occurs in the same way, except for needle punch forming, and when the organic nonwoven fabric is burned out during high-temperature use, even compacts with a bulk density of 0.1 before firing will become bulky. density i
The density of the alumina fiber mat was significantly lowered to 0.06 or less, and the tensile strength was also lowered to 50 to 100 F/CML'', which was not sufficient.

As a method to solve this drawback, Japanese Patent Application Laid-Open No. 60-8816
No. 2 and No. 60-252717 disclose a planter made by needle-punching a precursor laminate of alumina fibers before firing and then firing.

A method for obtaining blankets has been proposed. This method is said to be able to obtain blankets with higher strength than conventional methods. However, this method also requires an expensive fiber treatment agent and a needle punch molding machine for needle punching, and also has the disadvantage that if the needle breaks during needle punching, metal needles will be mixed into the product. there were.

[Problem 1 to be solved by the invention As mentioned above, it is possible to produce a mat-like molded product of crystalline alumina fibers with high heat resistance and high strength at high temperatures without using expensive fiber treatment agents or special equipment. A friend who is the inner cone of words.

[Means for solving problems]

In the present invention, a precursor main fiber laminate obtained by spinning a viscous liquid obtained by adding a water-soluble a organic polymer f:s to an aqueous fiber composition solution that provides gold @ oxide by firing treatment is used.
After humidification treatment at 00 mHg and pressure molding, 1
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below as a method for producing an inorganic fiber molded article, which is characterized by firing at a temperature of 100 to 1400°C.

The precursor fiber used in the present invention is obtained by adding a water-soluble organic compound to a high viscosity and spinning a metal salt solution.

The above-mentioned spinning solution can be prepared by, for example, adding an aqueous solution of a water-based organic polymer such as polyvinyl alcohol or polyethylene oxide to an aqueous solution of aluminum oxychloride containing a water-based metal salt such as magnesium or zorconium or colloidal silica, and then condensing the solution under reduced pressure. It can be obtained by the following method.

By spinning the Tokutomo filament in this way by a commonly used spinning method such as an extrusion method or a centrifugation method, a precursor fiber can be obtained. For example, in the case of the centrifugal method, spinning gt of 5 to 20 poise is supplied to the surface of a rotating disk with an opening over medium heat, and after spinning, it is evaporated in a high-speed air stream and dried to form a precursor. Becomes body fibers. In this case, the precursor fibers are photo-dried in order to prevent the fibers from forming a layer on the walls of the spinning device or forming droplets.

The moisture content of the precursor fibers dried in this way is 3% or less, and there is no adhesion between the fibers.For humidification of the previous 11L, the water vapor pressure is 10 to 1100tuxH, preferably 14 to
1 to 3 in a humidified atmosphere in the range of 50 rttx Hg.
This can be suitably carried out by a method such as leaving it on the bed for 0 minutes or passing the humidified air through the precursor main fiber laminate layer. J
The moisture content of the precursor after JItll is in the range of 3 to 12%, and a moisture content of about 4 to 8% is most suitable for pressure treatment. If the water ring pressure is 10 Hg, it will take a long time to humidify the precursor fibers, which is impractical;
When it exceeds 100OH, the surface of the previous @ body fiber laminate becomes 7101
If too much is used, the shape of the fibers will be distorted, and after firing, the surface of the laminate will have a crusty appearance, which is undesirable.

Pressure molding of the wetted 2IO precursor into plates, rolls, belts, etc. can be carried out using an ordinary press machine.◎The molding pressure, the water content of the precursor horizontal layer, and the bulk after pressure molding. Although it varies depending on the density, a very small pressure of less than 100 to 97 m2 is sufficient, and the force of the front @ body longing lateral layer body l! ! ! degree t O,061
1/an” Il, 1yaEE5Z type fb on top.

Firing 1siooo~1400℃, preferably 1200~
It is carried out at 1350°C. If it is less than 1000"C, the strength of the fibers is insufficient, and at 15[]()"C, the p + confinement heat shrinkage is large and the fire resistance fl! If it cannot be put into practical use as a thermal fiber molded article @1400-C! Even if IxJ is exceeded, the performance of the fiber will not improve to the rC mark, but rather the strength will decrease, making it uneconomical.

As described above, according to the present invention, the dried precursor 1-fiber lateral layer is moistened again for 1JrJ under specific conditions, and then pressure-molded to partially layer the precursor 1-fiber lateral layer, and fired as it is. This makes it possible to obtain a mat-like molded product having a high density and flexibility.

〔Example〕

Example 1 (Test 41) Aluminum oxychloride aqueous solution was added with colloidal silica (Snowtex Nichiro Kagaku) to a high ratio of 80% alumina and 20% silica.
% polyvinyl alcohol aqueous solution (Denka Popal B-1
7), the ratio of polyvinyl alcohol to the alumina and silica content is 8%. 1
The Mizusugi solution'1ffJ yarn stock solution with a viscosity of 15 boids was reduced to
I got a body and this #Ayu stacked storage is 200. @80% against temperature
After keeping it in a constant temperature bath with a water vapor partial pressure of 14 mmHg for 5 minutes and moistening it, it was compressed for 1 minute with a force of 50 m2 in the direction of the fiber length to form a bulk density skin Q 7 i 7 cm3 #frame. A press molded body was obtained.

This molded body was heated from room temperature to 800'C in a tunnel furnace with a temperature gradient of 1% to 11,500°C from the total room temperature to 1%.
0 minutes, 800'C to 1600℃ for 15 minutes, 15
Burn it out and hold it at 00℃ for 10 minutes to obtain a finished product. W degree B O,0951/, *”,
Tensile strength 500 g/c! Ivy in n2.

Processed by changing the degree as shown in the table f), the bulk density is 0.085μ
Above, a fired body with a tensile strength of 4601/m" or more was obtained. 9 @ Ratio 1] 2 rows 1 (Test A65)
/3" O precursor was treated with 1xJLt1 without seven lines, and the pressure mt was 0.0521/mt for 1 minute with a force of 50 #/m".
A precursor bottom shaped body of ``Ays'' was obtained. This shaped body was fired under the same conditions as in Example 1. The bulk density of the fired body was 0.05.
8.9 / Bi3 shell τ゛j tensile strength is 200. SF/C
M'Ko was unsatisfactory.

R912 (Test Shoulder 6) After heating the precursor with a bulk density of 0.041/an'' for 20 minutes at a water vapor partial pressure of 8 mg Hg and a pressure of 5 o/. The bulk density of the 7ta 91j finished product is 0.0721.
/ am” and the strength was also low.

Comparison Row 5 (Test/167) The same precursor obtained in Actual tIlfA Example 1 was used at a water vapor partial pressure of 102
tn Hg for 1 minute, then pressurized firing in the same manner as in Example 1. Both bulk specific gravity and tensile strength were good, and part of the surface of the mm body was 711] Due to excessive moisture, the surface of the fired body became taut and lacked softness. Mouth comparison row 4 (test 48.9) Real 211 row 1 2 test 5.4. Humidified pressure molding was carried out under almost the same conditions as above, and the firing temperature was changed to 800℃ and 1400℃.
Tensile strength was insufficient.

The bulk density and tensile strength of the fired body were measured as follows.

■ Cut out 100 pieces of specimen gold from the bulk density sample, M break of the section, width,
The length and thickness were measured to determine the bulk density. In addition, since the thickness has restorability, it was measured according to TIS R-3sii.

■ Tensile strength A sample with a shape of 50 (Fuku) x 500 (Length) was cut out from the sample, and the tensile strength in the 500 rm length direction was measured using a tensile tester (Toyo Zerudwin model UTM-4-100). The thickness of the mouth specimen measured using JI
Measured using SR-5511. The cross-sectional area of the test specimen was calculated using this II [t-] [Effects of the invention] By the uninvented method, the precursor fibers could be destroyed without using any special equipment or expensive auxiliaries. It is possible to easily produce molded articles such as fiber mats that have sufficient tensile strength and appropriate flexibility to be used as fireproof heat insulating materials.
can be obtained economically.

Patent Applicant Denki Kagaku Kogyo Co., Ltd. Procedural Amendment Written October 24, 1986 Commissioner of the Patent Office Kuro 1) Akio Yu 1, Indication of the case 1986 Patent Application No. 229493 2, Name of the invention Inorganic fiber molding 3. Relationship with the case of the person making the amendment Address of the patent applicant ■100 Column 5 of the detailed description of the invention in the specification, 1-4-1 Yurakucho, Chiyoda-ku, Tokyo, Contents of the amendment - 1) No. In lines 9 to 11 of page 2, ``The needle punching method was adopted because it was necessary to mold the material to a bulk density of 0.09 or more.However,'' should be corrected to ``used for the molding of the material.''

2) Correct "reinforcing agent" in line 5 of page 3 to "reinforcing material."

3) In the 6th @ line 10, correct "--in the shape of a belt, etc." to "in the shape of a belt, etc."

Claims (1)

[Claims] A precursor fiber laminate obtained by spinning a viscous liquid obtained by adding a water-soluble organic polymer to an aqueous solution of a fiber composition that provides a metal oxide by firing treatment is heated to a water vapor pressure of 10 to 100 mmH.
After humidification treatment at g and then pressure molding, 1100 to 1
A method for producing an inorganic fiber molded article, which comprises firing at 400°C.