JPH07102560B2 - Method for manufacturing nonflammable molded body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a nonflammable molded article which is used as a high temperature heat resistant material and which is excellent in heat resistance, heat insulation and strength.

[0002]

2. Description of the Related Art As a non-combustible molded article, for example, an inorganic paper mainly made of inorganic fibers is known. The main raw material for inorganic paper differs depending on the use of the inorganic paper, and the operating temperature is 1000 ° C.
In the above, artificial mineral fibers such as ceramic fibers and alumina fibers are used as raw material fibers. However, although the inorganic paper mainly composed of artificial mineral fibers has excellent heat resistance, it does not have sufficient heat insulating property, and a nonflammable molded product excellent in both heat resistance and heat insulating property has been demanded.

In addition, an inorganic paper containing potassium titanate whiskers as a main raw material is also known. Although this inorganic paper is excellent in heat insulation, its strength is not sufficient and its use is limited.

Further, a binder is required when making the inorganic fiber into paper, but conventionally, there is no suitable inorganic binder that gives the paper sufficient strength, and it has been used in combination with an organic binder, so that it has heat resistance. A molded product excellent in heat insulation and strength was not obtained.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is excellent in high temperature heat resistance and heat insulating properties, and also has high strength and light weight, and is excellent in workability. It is an object of the present invention to provide a method for producing a nonflammable molded article, which is capable of producing the molded article.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have identified potassium titanate whiskers and artificial mineral fibers as raw material fibers when producing molded articles from inorganic fibers. It has been found that the above object can be achieved by using a clay powder that is dispersed in and dissolved in water as a binder in various proportions, and the present invention has been completed based on this finding.

That is, according to the present invention, a mixed fiber containing 5 to 80% by weight of potassium titanate whiskers and 20 to 95% by weight of artificial mineral fibers is added to clay powder, based on the total amount of potassium titanate whiskers and artificial mineral fibers. Is dispersed in a dispersion solution dissolved in water, and water is removed from the obtained mixed fiber dispersion to obtain a molded body made of mixed fibers, which is dried to produce a non-combustible molded body. It provides a method.

In the present invention, the inorganic fibers are 5 to 8
0 wt% potassium titanate whiskers and 20 to 95 wt% artificial mineral fibers (hereinafter sometimes referred to as mixed fibers) are used. If the proportion of potassium titanate whisker fibers is less than 5% by weight, the heat insulating property is lowered, and if it exceeds 80% by weight, the heat resistance is lowered.

The potassium titanate whiskers are whiskers whose components are represented by the chemical formula K ₂ O.nTiO ₂ (n: real number), and the potassium titanate whiskers used in the present invention are typically tetratitanic acid. Examples thereof include potassium whiskers, potassium hexatitanate whiskers, and potassium octatitanate whiskers. The length and diameter are not limited as long as they are whiskers, but preferably the length is 1 μm to 30 μm and the diameter is 0.1 μm.
Those having a thickness of 10 μm are used.

The artificial mineral fibers used in the present invention include rock wool fibers, glass fibers, silicon nitride fibers, silicon carbide fibers, carbon fibers, zirconia fibers, magnesium oxysulfate whiskers, synthetic calcium silicate fibers, ceramic fibers, silica fibers. , Alumina silica fiber, alumina fiber and the like.

Particularly, the fiber length is 10 μm to 3 mm and the fiber diameter is 1
Ceramic fibers of μm to 5 μm are preferably used.

The use of glass fiber as the artificial mineral fiber improves the flexibility and strength of the molded product. The glass fiber is preferably used in combination with the ceramic fiber, and the addition amount thereof is preferably 2 to 50 parts by weight based on 100 parts by weight of the total amount of potassium titanate whiskers and the ceramic fiber. The glass fiber has a length of 1 mm to 10 mm and a diameter of 0.1.
It is preferable to use the one having a thickness of 5 μm.

In producing the non-combustible molded article of the present invention, within a range that does not impair the properties of the non-combustible molded article obtained,
In addition to potassium titanate whiskers and artificial mineral fibers,
Natural calcium silicate fibers (wollastonite), natural mineral fibers such as mountain bark, and carbon fibers may be used together. Moreover, you may use together organic fibers, such as a cellulose fiber and an aramid fiber.

When aramid fiber is added to the mixed fiber, the tensile strength of the molded product at room temperature is improved and the productivity in mass production at high speed is improved. The addition amount is preferably 2 to 50 parts by weight with respect to 100 parts by weight of the mixed fiber.

When cellulose fibers are added to the mixed fibers, the tensile strength of the molded product at room temperature is improved and the productivity in mass production at high speed is improved. The addition amount is preferably 2 to 10 parts by weight with respect to 100 parts by weight of the mixed fiber.

The length of the fiber added to the mixed fiber is preferably 1 μm to 30 mm, and the diameter of the fiber is preferably 0.1 to 30 mm.
It is 5 μm. Aramid fiber has a length of 3 mm to 10 mm,
It is preferable to use one having a diameter of 0.1 to 0.5 μm.
Cellulose fibers have a length of 3 mm to 10 mm and a diameter of 0.1.
It is preferable to use one having a thickness of 0.5 μm.

In the present invention, the above-mentioned mixed fibers are dispersed in a dispersion liquid in which clay powder is dispersed and dissolved in water, and water is removed from the obtained mixed fiber dispersion liquid to obtain a molded product of the mixed fibers.

The clay powder used in the present invention includes SiO ₂ content of 40 to 70% by weight and Al ₂ O ₃ content of 4 to 10% by weight.
% By weight, MgO content 5-20% by weight and H ₂ O content 5-15
A clay powder containing wt%, for example, a powder of Jiangxi clay produced in Jiangxi, China is preferably used. Other than clay powder, attapulgite powder is also preferably used. Clay powder is dried at 50-300 ℃ and 10-300
It is preferably used as a powder of mesh.

In the present invention, preferably, 1 to 10 parts by weight of the clay powder is added to water with respect to 100 parts by weight of water and sufficiently stirred to form a dispersion solution of the clay powder. It is preferable that the clay powder is completely dissolved in water, but if the clay powder is uniformly dispersed in water, not all the clay powder needs to be dissolved in water. Therefore, the dispersion solution in the present invention means both the one in which the clay is completely dissolved in water and the one in which the clay is not partially dissolved and is uniformly dispersed in the solution.

Next, 400 to 2000 parts by weight of the dispersion solution of the clay powder obtained above is added to 100 parts by weight of the mixed fiber, and the mixture is stirred until the fibers are uniformly dispersed in the solution. At this time, if necessary, alumina sol,
Addition of an inorganic substance such as silica sol, zirconia sol, sodium phosphate, bentonite, cordierite, zeolite, magnesia, yttria or zonotolite improves the heat resistance of the obtained molded product. Clay powder 10
10 to 100 parts by weight is preferable with respect to 0 parts by weight. The clay powder and the inorganic material may be mixed in advance and made into a slurry, which may be added to water before use.

Next, when a flocculant such as a polymer flocculant is added, the clay adheres to the fibers and the fibers coagulate. Moisture is appropriately removed by a method such as natural filtration or vacuum filtration. The amount of coagulant is preferably 3 to 10 parts by weight per 100 parts by weight of fiber. The agglomerated fibers and clay are made into a paper shape or formed into various shapes by a known method. As the molding method, there are a casting method, an extrusion method, a hot roll method, a doctor blade method, a papermaking method, a vacuum suction method, and the like, and when the one molded by these is a sheet-like material, it may be bent or bent, It can be cut, laminated, and secondary processed into complex shapes.

Next, this molded body is preferably 40-1.
The desired nonflammable molded product is obtained by drying at 20 ° C. This molded body is more preferably (normal temperature to 500 ° C to 1
When baked at a gradient temperature of (000 ° C.), organic substances and impurities contained in clay are removed, and further inorganic substances in clay are sintered to improve heat resistance. In this case, the clay retains its shape even if the organic matter is removed.

The obtained molded article is suitably used as a paper for heat insulating paper of a steel mold and the like, and as a thick sheet-like material for a heat-resistant sheet for metal processing and the like.

[0024]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

Example 1 10 parts by weight of Jiangxi clay to 300 parts by weight of water in a propeller stirrer (physical properties and chemical components are shown below)
The powder (average particle size 100 mesh) was added and stirred for several minutes, and it was confirmed that the clay was dissolved in water. Next, with respect to 300 parts by weight of this solution, 50 parts by weight of potassium titanate whiskers (trade name, manufactured by Nippon Whisker KK, fiber diameter 0.3 μm, fiber length 20 μm), ceramic fibers (SC1400, Nippon Steel Chemical Co., Ltd. product) 20 parts by weight (fiber diameter: 2.8 μm, fiber length: 10 mm) are added and stirred until the fibers are uniformly dispersed in water. Then, 2 parts by weight of Hymoloc (trade name, manufactured by Kyoritsu Organic Co., Ltd.) as a polymer coagulant was added to this fiber dispersion to coagulate the fibers, and then the fibers and water were separated, and a thickness of 0 was obtained using a hand strainer. A 4 mm paper was made. This was cut into a width of 20 mm and a length of 200 mm, and the tensile strength was obtained. The results of the physical properties and strength test of this paper are shown in Table 1.

Physical Properties Chemical Components (% by Weight) Relative Density 2.40 to 2.60 SiO ₂ 60.43 Density 300 Al ₂ O ₃ 6.38 Bulk Density 525 Fe ₂ O ₃ 2.30 pH 9 ± 0. 5 MgO 14.38 Surface Area 259 CaO 1.28 Whiteness 65 K ₂ O 0.54 CEC 26 Na ₂ O 0.19 (Cation Exchange Rate) TiO ₂ 0.22 Decolorizing Power 200 MnO 0.56 Moisture (%) <15 H ₂ O 11.83 Fluid powder burned down (1000 ° C.) 13.36 Molecular structural formula {Ca _0.10 K _0.09 N _0.04 } (Mg _5.46 Al _1.11 Fe ³⁺ _0.51 Ti _0.02 ) [Si _11.49 Al _0.51 ] O _{30 (OH) 4 (OH 2} ) 4 8H 2 O

Example 2 Potassium titanate whiskers (Tismo D,
Otsuka Chemical Co., Ltd. product name, fiber diameter 0.3 μm, fiber length 2
1 μm) 50 parts by weight, ceramic fiber (SC1400)
Using 20 parts by weight and 10 parts by weight of synthetic calcium silicate fiber (Cycatech H-08, trade name, manufactured by Tomoe Kogyo Co., Ltd., fiber length 300 μm, fiber diameter 6 μm), a paper having the same shape as in Example 1 was obtained. It was The results of the physical properties and strength test of this paper are shown in Table 1.

Example 3 Potassium titanate whiskers (Tismo D) as fibers
Using 50 parts by weight, 20 parts by weight of ceramic fiber (SC1400), and 10 parts by weight of glass fiber (fiber diameter 1 μm, fiber length 3 mm), a paper having the same shape as in Example 1 was obtained. The results of the physical properties and strength test of this paper are shown in Table 1.

Example 4 Potassium titanate whiskers (Tofica Y) as fibers
D) 50 parts by weight, ceramic fiber (SC1400) 20
Using 10 parts by weight of aramid fiber (trade name of Apierre, Unitika Ltd., fiber diameter 0.1 μm, fiber length 30 mm), the same shape of paper was obtained as in Example 1. The results of the physical properties and strength test of this paper are shown in Table 1.

Example 5 Potassium titanate whiskers (Tismo D) as fibers
Paper having the same shape as in Example 1 using 50 parts by weight, 20 parts by weight of ceramic fiber (SC1400), 10 parts by weight of glass fiber and 8 parts by weight of cellulose fiber (fiber diameter 0.1 μm, fiber length 30 mm). Got The results of the physical properties and strength test of this paper are shown in Table 1.

Comparative Example 1 As a fiber, potassium titanate whiskers (Tofica Y
D) A paper having the same shape as in Example 1 was obtained by using 70 parts by weight. The results of the physical properties and strength test of this paper are shown in Table 1.
Shown in. This paper was not suitable for practical use because the fiber length of potassium titanate whiskers was 20 μm and the entanglement between the fibers was small and the strength was weak.

Comparative Example 2 Using 70 parts by weight of ceramic fiber (SC1400) as the fiber, a paper having the same shape as in Example 1 was obtained.
The results of the physical properties and strength test of this paper are shown in Table 1. This paper had a large infrared transmittance and was poor in heat insulation.

Example 6 Potassium titanate whiskers (Tofica Y as fibers)
D) 5 parts by weight, synthetic heavy calcium silicate (trade name HCS manufactured by Yabashi Industry Co., Ltd., shape: porous sphere, particle size 20-80)
μm, crystal shape: needle-shaped) 10 parts by weight and ceramic fiber (SC1400) 30 parts by weight, and attapulgite (paricoskite) (high yield, Showa Mining Co., Ltd. trade name, hydrous magnesium silicate, average particle size) as clay powder 20 parts by weight (300 mesh), and the other example 1
A paper of the same shape was obtained in the same manner as in. 15 pieces of this are piled up and pressed by a press machine, and vertical and horizontal 300 mm
The board of was produced. 200mm long from this board,
A test piece having a width of 40 mm and a thickness of 5 mm was cut out. Table 1 shows the results of the physical properties and strength test of this board.

The physical property and strength tests were conducted at room temperature.
The test piece which was heated from room temperature to 500 ° C. over 30 minutes, kept for 10 minutes, and naturally cooled to room temperature.
A test piece which was heated to 0 ° C and held for 10 minutes, further heated to 800 ° C for 30 minutes and held for 10 minutes, and naturally cooled to room temperature, which was heated to 800 ° C and held for 10 minutes Is further heated to 1000 ° C over 30 minutes, and 1
It was held for 0 minutes, and this was measured for four types of test pieces, which are naturally cooled test pieces.

The infrared transmittance was measured by an infrared spectrometer. Those having a small value have excellent heat insulating properties.

[0036]

[Table 1]

[0037]

Industrial Applicability According to the present invention, it is possible to obtain a molded article such as paper, sheet or the like which is excellent in high-temperature heat resistance, fire resistance and thermal conductivity, has high strength and is lightweight, and is excellent in workability.

In particular, when the paper is used, a paper having flexibility similar to that of the conventional paper was obtained by using only the inorganic binder.

Claims (6)

[Claims] 1. A mixed powder containing 5 to 80% by weight of potassium titanate whiskers and 20 to 95% by weight of artificial mineral fibers, based on the total amount of potassium titanate whiskers and artificial mineral fibers, and clay powder in water. A method for producing a non-combustible molded article, which comprises dispersing in a dispersion solution in which a dispersion is dissolved, removing water from the obtained mixed fiber dispersion liquid to obtain a molded article made of mixed fibers, and drying the molded article. 2. The method for producing a non-combustible molded article according to claim 1, wherein the artificial mineral fiber is a ceramic fiber. 3. The method for producing a nonflammable molded article according to claim 1, wherein the artificial mineral fiber is a mixture of ceramic fiber and glass fiber. 4. The mixed fiber is 2 to 50 per 100 parts by weight of the total of potassium titanate whiskers and artificial mineral fibers.
The method for producing a non-combustible molded article according to claim 1, further comprising a part by weight of aramid fiber. 5. The mixed fiber is 2 to 10 with respect to a total of 100 parts by weight of potassium titanate whiskers and artificial mineral fibers.
The method for producing a non-combustible molded article according to claim 1, which further comprises parts by weight of cellulose fibers. 6. The method for producing a non-combustible molded article according to claim 1, wherein the clay is Jiangxi clay.