US4305992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intumescent sheet material
Assignee: 3M Co
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Filing: 1979-11-28
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Granted: 1981-12-15
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Expires: 1999-11-28
Abstract
Abstract Flexible intumescent sheet materials having greatly decreased negative expansion characteristics in the range of 200° to 400° C. and which are thermally resistant and resilient after expansion are disclosed. The flexible intumescent sheets are particularly useful for mounting automotive catalytic converter monoliths.
Inventors
- 👤 Roger L. Langer
- 👤 Alan J. Marlor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:58
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2839; F01N3/2853; F01N3/2857; D; D21; D21H; D21H13/00; D21H13/36; D21H13/38; D21H13/44; D21H21/00; D21H21/14; D21H21/34; D21H5/00; D21H5/12; D21H5/18; F01N2350/00; F01N2350/02; Y; Y10; Y10S; Y10S106/00; Y10S106/03; Y10S428/00; Y10S428/913; Y10S428/92; Y10T; Y10T428/00; Y10T428/25; Y10T428/251; Y10T428/26
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
A flexible intumescent sheet useful for mounting automotive catalytic converter monoliths comprising from 40% to 65% by weight of unexpanded vermiculite flakes having particle sizes of from about 0.1 mm. to about 6 mm. treated by extended soaking in an aqueous ammonium solution and being substantially completely ion-exchanged with NH 4 + cations, from 25% to 50% by weight of inorganic fibrous material and from 5% to 15% of binder, said sheet upon exposure to heat from an engine exhaust being capable of undergoing thermal expansion, said sheet having a maximum percent negative expansion of about 10% at about 300° C. and returning to its original starting thickness or greater at about 350° C.
Claim 2
Dependent Claim
114 words
A flexible intumescent sheet useful for mounting automotive catalytic converter monoliths comprising from 40% to 65% by weight of unexpanded vermiculite flakes having particle sizes of from about 0.1 mm. to about 6 mm. treated by extended soaking in an aqueous ammonium solution and being substantially completely ion-exchanged with NH 4 + cations, from 25% to 50% by weight of inorganic fibrous material and from 5% to 15% of binder, said sheet upon exposure to heat from an engine exhaust being capable of undergoing thermal expansion, said sheet having a maximum percent negative expansion of about 10% at about 300° C. and returning to its original starting thickness or greater at about 350° C.
Claim 3
Dependent Claim
22 words
A flexible intumescent sheet according to claim 1 wherein the treated vermiculite is vermiculite which has been ion-exchanged with ammonium dihydrogen phosphate.
Claim 4
Dependent Claim
21 words
A flexible intumescent sheet according to claim 1 wherein the treated vermiculite is vermiculite which has been ion-exchanged with ammonium carbonate.
Claim 5
Dependent Claim
21 words
A flexible intumescent sheet according to claim 1 wherein the treated vermiculite is vermiculite which has been ion-exchanged with ammonium acetate.
Claim 6
Dependent Claim
21 words
A flexible intumescent sheet according to claim 1 wherein the treated vermiculite is vermiculite which has been ion-exchanged with ammonium hydroxide.
Claim 7
Dependent Claim
22 words
A flexible intumescent sheet according to claim 1 wherein the inorganic fibrous material is asbestos, soft glass fiber or refractory alumino-silicate fiber.
Claim 8
Dependent Claim
16 words
A flexible intumescent sheet according to claim 1 wherein the binder is an organic elastomeric material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |