JPH0226850A - Short fiber of oxynitride - Google Patents

Abstract

PURPOSE:To obtain the short fibers which have a high serviceable temp. and are useful as the raw material for an inexpensive heat insulating material having high strength and high elasticity by heating and melting a mixture composed of SiO2, Si3N4 and specific metal oxide and mixing this melt with a high-velocity inert gas. CONSTITUTION:The SiO2, the Si3N4 or metal nitride, oxide of M1 (Ca or Ca and Mg) or compd. which forms the oxide of M1 by thermal decomposition, and compd. which forms the oxide of M2 by thermal decomposition are mixed. This mixture is heated and melted at 1400-1950 deg.C in an inert gaseous atmosphere. The molten glass is mixed with the high-velocity inert gas to obtain the desired short glass fibers. The above-mentioned short fibers are short fibers of the oxynitride glass having the glass system Si-M1-M2-O-N and contg. the SiO2, the Si3N4 and the M1O at the ratios, by molar %, satisfying formulas I, II (M1 is Ca, Ca and Mg; M2 is metals exclusive of Ca and Mg).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to short oxynitride glass fibers used in heat insulating materials, sound absorbing materials, etc., a method for manufacturing the same, and a manufacturing apparatus.

BACKGROUND ART Conventionally, A-glass fibers, which are easy to manufacture and handle and are inexpensive, have been widely used as heat insulating materials, sound absorbing materials, filtering materials, and the like. However, the A-glass fiber itself has low mechanical strength and its operating temperature is low, at about 350°C. Asbestos has been known as another inexpensive fiber that can be used for similar purposes, but its use has been discouraged in recent years due to its harmful effects on the human body.

An object of the present invention is to provide short oxynitride glass fibers that can be used at a high temperature of up to about 800° C. and are excellent as raw materials for heat insulating materials, which are high in strength, highly elastic, and inexpensive.

Means for Solving the Problems The present invention has a St-NL-Mt-0-N glass system,
and 5ins, Si, Nt and M1O in mol%, the following formulas (a) and (b): 0.65≦(SiOt+3SL3N4+MIO)/(
loo+2S 1aN4)<1”
・(a) 0.7≦(S 102+ 3 S 13N4
)/MIO≦2.3...(b) Provides an oxynitride glass short fiber containing an amount that satisfies [where Ml is Ca, or Ca and Mg; Mf means a metal other than Ca1M+r] It is something to do.

Further, the present invention provides (i) SiO,; metal nitride; Ca
b, or a step of mixing CaO+MgO; and a metal oxide, (11) mixing the mixture under an inert gas atmosphere.
A step of heating and melting at 400 to 1950°C, and (i
ii) A method for producing short oxynitride glass fibers, which comprises a step of mixing the molten glass with a high-speed inert gas, and an apparatus for producing the same.

Oxynitride glass, which is the material for the short glass fibers of the present invention, particularly contains a large amount of nitrogen of 15 atomic % (hereinafter referred to as atomic %) or more, and therefore has tight crosslinks due to SiN bonds. Therefore, the glass has a tighter glass network, greater surface hardness, and higher elasticity than conventionally known glasses.

The oxynitride glass used in the short glass fibers of the present invention has a SI MI Mt O-N glass system. Here, M is Ca or Ca+Mg. That is,
The oxynitride glass is Si-Ca-MtO
N, or Si-Ca-Mg-M.

It has 0-N glass system. As the metal M, for example, A
l5SrSLa, Ba, YST iS Zr1NaSK
, 5bSB, etc. These metals alone
Alternatively, two or more types may be combined. therefore,
The typical composition of the short glass fibers of the present invention is Ca-5i-A
l-0-NSNa-CaSi-0-N, La-Ca-
5i-Al-0-N.

Na-B-Ca-9i-0-NSMg-Ca-9iAl
-0-N, 5i-Ca-AI-0-N, Y-Al-
Ca-9i-0-N, Na-B-Ca-Si-Al
-P-0-N, Ca-Mg-'5i-Al-0-N.

S r -Ca-Mg -S i -AI -0-N5
Ba-Ca-Mg-Si-AI-0-N, Y-C
a-Mg-9i-AI-0-N, etc.

The oxynitride glass, which is the material of the short fibers of the present invention, is expressed by the following formulas (a) and (b), with each component expressed in mol%.
・0.65≦(SiOz+ 35isN4+CaO+Mg
0) / (100+ 2 S 13N4) < 1
...(a) 0.7≦(S io t+ 38
i*N4)/CaO+MgO≦24·-(b) [wherein CaO and MgO are each CabSMgO.

Or it means the mol% of the compound converted into these based on CaOlMgO]. The oxynitride glass contains more Ca than conventionally known oxynitride glasses.

Contains Mg. Said (S io t+ 3 S 1a
N4+Cao+MgO)/(LQQ+2S
is N 4) smaller than 0.65, crystallization occurs and glass cannot be obtained. On the other hand, (S io t+ 3 Si
3N 4)/CaO+ If MgO is less than 0.7 or exceeds 2.3, the nitrogen content of the resulting glass will be less than 15 at%, and a high elastic modulus will not be obtained.

The short glass fiber of the present invention has a nitrogen content of 15 to 30 at%,
Elastic modulus 12,500-25,000kg/++un'',
It has a tensile strength of 70 to 500 kg/open 2.

Note that if the nitrogen content exceeds 30 at%, crystallization occurs and glass cannot be obtained. The nitrogen content can be adjusted by adjusting the amount of raw materials added.

The fineness of the short glass fibers is preferably 3 to 20 μm. If the fineness is smaller than this range, spinning will be difficult, while if it is larger than this range, the strength will drop significantly. Also,
The fiber length of the short glass #a fibers is preferably 10 to 200 mm. If the fiber length is less than 10 mm, the reinforcing properties will be low when made into F'RP. On the other hand, if the fiber length exceeds 200 mm, handling becomes difficult.

Furthermore, the short glass fibers of the present invention have a heat resistance of about 800° C. and are excellent as a heat insulating material.

To obtain the short glass fibers of the present invention, (i) SiOt; (ii) S 1sNa or other metal nitrides: (i)
ii) Cab, , metal oxide other than MgO; and (i
v) Mixing CaO or CaO+MgO.

Preferred examples of the metal oxide (iii) include A
ltos, BaO1sb, o, 5rO1NatO1K
,0,Lag'3,Ce Ot,Y,03,ZrO,,
Examples include TiOx, N at O% K t 01 Btu, and the like. Instead of these metal oxides, compounds that become metal oxides by thermal decomposition, such as carbonates, hydroxides, and oxalates, may be used. These compounds may be used alone or in combination.

Metal nitrides (ii) other than the above 5isN+ include A
Examples include IN and BN. AIt as metal oxide
AIN is preferable when using OS, and BN is preferable when using 8.03. Two or more types of these nitrides may also be combined.

The oxynitride glass contains CaO as an essential component, and may further contain MgO together with CaO. Furthermore, instead of CabSMgO, materials that become these oxides by thermal decomposition may be used.

Next, these components (i) to (1v) are represented by the above formula (a).
, (b) in a satisfactory ratio.

The oxide and nitride are mixed and heated to form oxynitride glass. The melting of the mixture is 1400-19
At 50°C, 1 minute to 3 hours, heating rate lO to 800°C
/min under nitrogen or an inert atmosphere. The inert atmosphere may be at normal pressure. For melting, a heating furnace such as an electric furnace or an image furnace is used.

Alternatively, a mixture of only oxides is first melted in a crucible in air, then ground, and then this oxide powder is mixed with nitrides and melted at high temperature under an inert atmosphere to form an oxidizer. Nitride glass can also be obtained.

The obtained oxynitride glass is cooled quickly or slowly. The cooled oxynitride glass was transferred to a spinning device heated to 1100-1600°C, and the spinning speed was 20-3000 m under an inert atmosphere.
Spinning takes 7 minutes.

Alternatively, a feeder may be used to continuously supply the glass raw material to the heating furnace in the spinning device, and the molten glass will be heated directly to the heating furnace in the spinning device at a temperature of 1100 to 160° below the melting temperature.
The short fibers may be cooled to 0° C. and then continuously spun under an inert atmosphere.

To spin molten glass into short fibers, an inert gas such as high-pressure nitrogen is blown onto the molten glass at high speed to scatter the molten glass into fibers, which are then cooled.

The molten glass is supplied either directly from the melting section or through a spinning section that disperses the molten glass while rotating, and an inert gas such as nitrogen is blown from the surroundings at high speed into the oxynitride glass. Obtain short fibers.

Next, a preferred spinning apparatus for producing the oxynitride glass short fibers of the present invention will be described. The apparatus 1 of the present invention includes a glass raw material container 2 that stores raw materials and serves as a raw material supply section, a melting container 3 that is a melting section that melts the raw materials supplied from the raw material container, and a frit that is supplied from the melting container 3. It consists of a spinning section 4 that mixes glass and inert gas.

The raw material container 2, melting container 3, and spinning section 4 are all maintained in an inert gas atmosphere with an oxygen concentration of 200 ppm or less.

A raw material container 2 is provided with a nitrogen line 5 and connected to a melting container 3, and stores raw material 6 for oxynitride glass. Further, a heater 7 is provided around the melting container 3 to heat and melt the supplied glass raw material. Next, the spinning section 4 is arranged below the melting container 3, and includes a rotating container 9 having a large number of spinning holes 8 on the side surface, and a rotating container 9 arranged on the side and below the rotating container 9 toward the center of the apparatus. and a nitrogen nozzle 10. The molten glass scattered from the spinning hole 8 is made into short fibers by the nitrogen ejected from the nitrogen nozzle IO. The melting container 3 and the spinning section 4 are housed in a casing 11, and maintained in a nitrogen atmosphere by a nitrogen line 12 provided in the casing. Further below the device are a binder nozzle 13 for spraying binder onto the glass fibers and an air jet nozzle 14 for cooling.
is provided to condense and cool the short glass fibers 15.

Director X Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Short glass fibers were manufactured using the short glass fiber manufacturing apparatus shown in FIG. 1 with the following raw material composition.

Composition Mol% 5ide 4.8 S 13N-14,5 Ca0 48.4 ALO332,3 The above raw materials were supplied to raw material container 2, and melted at 1750°C in a nitrogen atmosphere with an oxygen concentration of 1100 pp or less in the melting container.
Melting was performed at The molten glass was spun at a temperature of 1530°.
Discharge from the rotating container (200 times/min) at C, and blow out nitrogen from the nitrogen nozzle at 150 C/min to collect short glass fibers (
Nitrogen content: 15.5 at%) was produced. The mechanical properties of the obtained short glass fibers are as follows: tensile strength 5' 50 kg/m
n'', tensile modulus 16500 kg/mm'', fiber diameter 5
~10 μm, and the fiber length was 3 to 12 cm.

Examples 2 to 8 and Comparative Examples 1 to 8 Glass short m vertebrae were obtained in the same manner as in Example 1 using the compositions and conditions shown in Table 1 below. The results are also shown in Table 1.

As is clear from Table 1, Comparative Examples 1 and 2 where formula (a) is less than 6<0.65, Comparative Examples 3 and 4 where formula (b) is less than 0.7, and formula (b) In both Comparative Examples 5 and 6, which exceeded 2.3, no glass was obtained and crystallization occurred. In addition, Comparative Examples 7 and 8 exceeded the formula (b) #(2, 3) and could only obtain glasses with low elasticity.In contrast, Examples satisfying both formulas (a) and (b) 1-8
Both exhibit excellent physical properties.

Effects of the Invention The short glass fibers of the present invention can be used up to about 800°C, and have a higher usage temperature than A glass. In addition, its mechanical strength is equivalent to that of asbestos, and it has no effect on the human body.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an apparatus used for spinning short glass fibers of the present invention. The main symbols in the figure are as follows. 2: Raw material container, 3: Melting container, 5.12: Nitrogen line,
9: rotating container, lO: nitrogen nozzle.

Claims (5)

[Claims] (1) Has Si-M_1-M_2-O-N glass system,
And SiO_2, Si_3N_4 and M_1O in the following formulas (a) and (b) in mol%: 0.65≦(SiO_2+3Si_3N_4+M_1O
)/(100+2Si_3N_4)<1...(a) 0.7≦(SiO_2+3Si_3N_4)/M_1O
≦2.3...(b) [In the formula, M_1 is Ca, or Ca and Mg; M_
2 means metals other than Ca and Mg]. (2) Claim 1, wherein the nitrogen content is 15 atomic % or more.
Short glass fibers as described. (3) The diameter of the glass fiber is 3 to 20 μm, and the fiber length is 1
The short glass fiber according to claim 1 or claim 2, which has a length of 0 to 200 mm. (4) The method for producing short glass fibers according to claim 1, which comprises the following steps (i) to (iii). (i) SiO_2:Si_3N_4 or metal nitride;
A step of mixing an oxide of M_1 or a compound that becomes an oxide of M_1 by thermal decomposition; and an oxide of M_2 or a compound that becomes an oxide of M_2 by thermal decomposition; 19
heating and melting at 50° C.; and (iii) mixing the molten glass with a high velocity inert gas. (5) A glass raw material supply section, a melting section that is connected to the raw material supply section and melts the glass raw material, and a spinning section that is connected to the melting section and mixes the molten glass supplied from the melting section with an inert gas. 2. The apparatus for producing short glass fibers according to claim 1, wherein the raw material supply section, the melting section, and the spinning section are in an inert gas atmosphere with an oxygen concentration of 200 ppm or less.