# US 8,540,941 B2 · Alumina-silica-based fiber, ceramic fiber, ceramic fiber complex, retaining seal material, production method thereof, and alumina fiber complex production method

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- Number: US 8,540,941 B2
- Document ID: US8540941B2
- Status: Granted
- Kind: B2
- Application number: 12/273,947
- Filed: 2008-11-19
- Published: 2009-06-04
- Granted: 2013-09-24
- Earliest claimed: 2001-05-25
- Assignees: Ibiden Co., Ltd.
- Applicants: Kazutomo Tanahashi; Masakage Doushita; Hidetomo Takahashi
- Inventors: Kazutomo Tanahashi; Masakage Doushita; Hidetomo Takahashi
- Web page: https://patentgrep.com/patent/US8540941B2

## CPC

- C04B 35/62245: {rich in aluminium oxide}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- C04B 35/117: Composites
- C04B 35/80: Fibres, filaments, whiskers, platelets, or the like
- D01D 5/04: Dry spinning methods {(D01D5/0038 takes precedence)}
- D01D 5/253: with a non-circular cross section; Spinnerette packs therefor (D01D5/38 takes precedence)
- D01F 9/10: by decomposition of organic substances (D01F9/12 takes precedence)
- F01N 3/2853: {using mats or gaskets between catalyst body and housing}
- F01N 3/2864: {the mats or gaskets comprising two or more insulation layers}
- C04B 2235/422: Carbon
- C04B 2235/526: characterised by the length of the fibers
- C04B 2235/5264: characterised by the diameter of the fibers
- C04B 2235/5268: Orientation of the fibers
- C04B 2235/5284: Hollow fibers, e.g. nanotubes
- C04B 2235/656: characterised by specific heating conditions during heat treatment
- C04B 2235/6567: Treatment time
- C04B 2235/658: Atmosphere during thermal treatment
- C04B 2235/80: Phases present in the sintered or melt-cast ceramic products other than the main phase
- C04B 2235/96: Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B 2235/9661: Colour
- F01N 2330/06: Ceramic, e.g. monoliths
- F01N 2330/14: Sintered material
- F01N 2350/04: with means compensating thermal expansion
- Y10T 428/249928: Fiber embedded in a ceramic, glass, or carbon matrix
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A manufacturing method by which alumina-silica based fibers excellent in mechanical strength can be readily and securely obtained. The method obtains precursor fibers as a material by using an alumina-silica based fiber spinning stock solution for use in an inorganic salt method. Next, the precursor fibers are heated under an environment which makes it difficult to carry out an oxidizing reaction on the carbon component contained in the precursor fibers. Thus, the precursor fibers are sintered to obtain alumina-silica based fibers.

## Claims

### Claim 1

A holding seal material comprising:
alumina-silica based fibers aggregated into a mat shape as a constituent element, and is placed in a gap between a ceramic body capable of allowing a fluid to flow through the inside thereof and a metal shell covering the outer circumference of the ceramic body, wherein
a dispersion of fiber diameter in said alumina-silica based fibers is within ±3 μm, and
a ceramic cross linking bridge comprising a substance made from the alumina-silica based fibers adjoins adjacent ones of the alumina-silica based fibers together in an overlapping area of the alumina-silica based fibers.

### Claim 2 (depends on 1)

The holding seal material according to claim 1, wherein
a dispersion of fiber length in said alumina-silica based fiber is within ±4 mm.

### Claim 3 (depends on 1)

The holding seal material according to claim 1, wherein
a shot content is 3% by weight or less.

### Claim 4 (depends on 1)

The holding seal material according to claim 1, wherein
an average fiber diameter of said alumina-silica based fiber is 5 to 15 μm, an average fiber length thereof is 5 to 20 mm, a dispersion of fiber length therein is within ±4 mm, and no shots are contained therein.

### Claim 5 (depends on 1)

The holding seal material according to claim 1, wherein
said ceramic body includes a catalyst carrier, and the holding seal material is used as a holding seal material for a catalyst converter.

### Claim 6 (depends on 1, 2, 3, 4, 5)

A method for manufacturing the holding seal material according to any one of claims 1-5, comprising:
a spinning step for obtaining a precursor fiber comprising an alumina-silica based fiber by using a spinning stock solution prepared by using an inorganic salt;
a sintering step for heating and sintering the precursor fiber;
a cutting step for chopping a long fiber of the resultant precursor fiber into a predetermined length to obtain a short fiber; and
a forming step for three-dimensionally aggregating the short fiber to form a mat-shaped fiber aggregation.

### Claim 7 (depends on 1)

The holding seal material according to claim 1, wherein said ceramic cross linking bridge is formed during an anneal of the alumina-silica based fiber at temperatures of 1000˜1300° C.