JPS6128072A - High heat resistant fiber and its production - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to highly heat-resistant fibers that exhibit little strength deterioration even at high temperatures of 600°C or higher, and include fiber composite agglomerated metals, high-temperature insulation materials, high-temperature sealing materials, It can be used in fields that require fiber strength at high temperatures, such as

[Conventional technology]

Glass fibers have conventionally been surface-treated with chlorosilane, aminosilane, or the like.

Further, JP-A-58-108095 discloses a method for treating glassy surfaces with zirconium oxyorganic acid.

In general, JP-A No. 58-28794 discloses a surface treatment method in which an organic titanium compound and water vapor are sprayed to form a film on the surface of an inorganic fiber through a hydrolytic condensation reaction.

Further, Japanese Patent Publication No. 5B-7657 discloses a method of treating the surface of inorganic fibers with the vapor of an organic halogenated titanium compound.

Fibers subjected to these treatments have high strength at room temperature, with less deterioration in strength due to mechanical contact due to the protective film formed on the fiber surface. However, fibers treated with these methods have the disadvantage that their strength is significantly reduced at high temperatures of 60 G'C or higher due to the decomposition and disappearance of the treatment agent, as well as the expansion and generation of cracks that are typical of glassy materials. have. In addition, silica and alumina ceramic fibers are produced by electrically melting approximately equal amounts of high-purity silica and alumina, and then blowing the resulting trickle with high-pressure air or steam.
It has been known as a fiber that has a heat resistance of 1000''C or more, but because this fiber is glassy, cracks that occur during manufacturing and subsequent mechanical contact will expand due to heat treatment, resulting in a decrease in strength. This has the disadvantage that its use in applications requiring high-temperature strength is greatly restricted.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a high heat resistant fiber and a method for producing the same which improve the drawbacks of the prior art, that is, a decrease in strength at high temperatures. The above objective is achieved by providing the following.

[Means for solving problems]

The present invention is characterized in that a metal oxide coating is formed on the surface of the silica or alumina ceramic fiber in order to prevent the strength from decreasing at high temperatures.

In the present invention, an alcohol solution of metal alcohol V-) is impregnated on the surface of silica and alumina ceramic fibers, and then the metal alcoholate is first hydrolyzed by contacting with water or steam, and then heated to 500 to 600°C. It is characterized by forming a uniform metal oxide film by heat treatment at a temperature of .

[Action and effect]

The present invention forms a uniform metal oxide film on the surface of silica- and alumina-based ceramic fibers to fill and cover cracks, which are one of the causes of a decline in the high-temperature strength of ceramic fibers, thereby increasing the strength of the ceramic fibers. This prevents a decrease in

With regular silica and alumina fibers that do not have such a film, their strength drops to below room temperature i at temperatures as high as 800°C. The highly heat-resistant edge a of the present invention, on which an oxide film is formed, maintains the strength of g-τ at room temperature even at 800°C, and has the excellent effect that the decrease in strength is small.

Next, the reason for limiting each composition ratio of the metal oxide film formed on the surface of the highly heat-resistant fiber of the present invention will be explained.

If AlxOa exceeds 50% by weight, a homogeneous and stable glassy film will not be formed and the effect of preventing a decrease in fiber strength will be lost, so it is necessary to limit the content to 50% by weight or less.

If Ti0z exceeds 80% by weight, a homogeneous and stable glassy film will not be formed and the effect of preventing a decrease in fiber strength will be lost, so it is necessary to keep the content to 80% by weight or less.

In the production of the highly heat-resistant fiber of the present invention, in order to improve not only the fiber strength at high temperatures but also the properties such as the emissivity of the fiber surface, Zr (h) and Zr (which forms B2O3) are added.
Metal alcoholates such as OCz Ha)4 and B (QCs Hs)a, Al
(OCskh)s, T i (OCsHy)a, etc. may be used in combination.

〔Example〕

Next, examples of the present invention will be described.

Examples 1 to 8 Commercially available silica and alumina fibers (e.g. Ibiwool)
- After being immersed in an alcoholic solution of metal alcoholates mixed in a predetermined amount so as to have the proportions shown in Table 1, it is taken out, brought into contact with water vapor, and further heat-treated at a temperature of 800°C for 2 hours to produce the present invention. A highly heat resistant fiber was obtained.

The tensile strength of the highly heat-resistant fibers of the present invention of Examples 1 to 8 thus obtained was measured after heat treatment at 800°C for 2 hours, and the results were combined with the values of ordinary ceramic fibers (comparative example). It is shown in Table 1.

As can be seen from Table 1, the strength of the high heat resistant fiber of the present invention is:
This is more than twice as strong as ordinary ceramic fibers, indicating that there is little decrease in strength at high temperatures.

Table - Table

Claims (1)

[Claims] 1. A highly heat-resistant fiber characterized by forming a metal oxide film on the surface of a silica or alumina ceramic fiber. 2. The highly heat-resistant fiber according to claim 1, wherein the metal oxide film contains 50% by weight or more of SiO_2. 3. The metal oxide film is SiO_2 and Al_2O_3
Consisting of SiO_250-100% by weight, balance Al_
Claim 1 characterized in that it consists of 2O_3
High heat resistant fiber according to item 1 or 2. 4. The metal oxide film is composed of SiO_2 and TiO_2, SiO_2 is 70-100% by weight, and the balance is Al_2O.
The highly heat-resistant fiber according to claim 1 or 2, characterized in that it consists of _3. 5. A method for producing highly heat-resistant fibers, which comprises impregnating metal alcoholate on the surface of silica or alumina ceramic fibers, then contacting them with water, and further heat-treating them. 6. Claims characterized in that the impregnation of the metal alcoholate is carried out by either a method of immersing the ceramic fiber in an alcoholic solution of the metal alcoholate or a method of spraying vapor of the solution onto the ceramic fiber. The manufacturing method according to item 5. 7. The contact with water is carried out by either immersing the metal alcoholate-impregnated fibers in water or by spraying water vapor onto the fibers. Manufacturing method described in section. 8. The metal alcoholate is Si(OC_2H_5)_
The manufacturing method according to any one of claims 5 to 7, characterized in that the method contains 46% by weight or more of 4. 9. The metal alcoholate is Si(OC_2H_5)
Si(OC_4) and Al(OC_3H_7)_3
_2H_5)_4 is 46 to 100% by weight, the balance is Al(
OC_3H_7)_3. The manufacturing method according to any one of claims 5 to 8. 10. The metal alcoholate is Si(OC_2H_5
)_4 and Ti(OC_3H_7)_4, Si(O
C_2H_5)_4 is 70 to 100% by weight, the balance is Ti
(OC_3H_7)_3. The manufacturing method according to any one of claims 5 to 8. 11. The manufacturing method according to any one of claims 5 to 10, wherein the heat treatment is performed at a temperature within a range of 500 to 800°C.