Patent US4129525A successfully refreshed from Google Patents.
US4135022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Built-up roofing using sulfur asphalt
Assignee: Petro Canada Inc
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Filing: 1975-10-07
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Granted: 1979-01-16
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Expires: 1995-10-07
Abstract
Abstract The disclosure describes built-up roofing having improved resistance to spreading of fire, fabricated from two or more layers of felt impregnated with asphalt based saturant with asphalt based coating spread on top of each felt layer; the saturant asphalt or coating asphalt or both are blends of 90 - 45% asphalt with 10 - 55% sulfur. The roofing is built-up in the conventional manner by "mopping" fluid asphalt based coating onto felt layers impregnated with asphalt based impregnant. A protective layer of inert mineral aggregate (e.g. gravel) optionally covers the top coating.
Inventors
- 👤 Gerhard J. A. Kennepohl
- 👤 Laverne J. Miller
- 👤 David C. Bean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:29
CPC Classifications
E; E04; E04D; E04D11/00; E04D11/02; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10S428/921; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/25; Y10T428/31504; Y10T428/31815; Y10T442/00; Y10T442/50; Y10T442/51; Y10T442/53
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
An asphalt based built-up roofing structure having a substantially rigid deck covered with multiple layers of felt impregnated with an asphalt based saturant, and a separately applied asphalt based coating on top of each layer of felt, the bottom felt layer being fastened to said rigid deck, each superposed impregnated felt layer also being firmly adhered to the asphalt based coating applied to the felt layer thereunder and with at least one of said saturant and said coatings consisting of a uniform blend of from 10% to 55% sulfur dispersed in 90% to 45% by weight of asphalt, with any of the sulfur which does not dissolve in the asphalt being dispersed as finely divided particles in the size range below substantially 50 microns.
Claim 2
Dependent Claim
124 words
An asphalt based built-up roofing structure having a substantially rigid deck covered with multiple layers of felt impregnated with an asphalt based saturant, and a separately applied asphalt based coating on top of each layer of felt, the bottom felt layer being fastened to said rigid deck, each superposed impregnated felt layer also being firmly adhered to the asphalt based coating applied to the felt layer thereunder and with at least one of said saturant and said coatings consisting of a uniform blend of from 10% to 55% sulfur dispersed in 90% to 45% by weight of asphalt, with any of the sulfur which does not dissolve in the asphalt being dispersed as finely divided particles in the size range below substantially 50 microns.
Claim 3
Dependent Claim
36 words
A built-up roofing structure as claimed in claim 1 in which both the asphalt based saturant and the asphalt based coatings are blends of from 10% to 55% sulfur dispersed in 90% to 45% of asphalt.
Claim 4
Dependent Claim
30 words
A built-up roofing structure as claimed in claim 2 in which the saturant and coatings are blends of from 20% to 40% sulfur dispersed in 80% to 60% of asphalt.
Claim 5
Dependent Claim
24 words
A built-up roofing structure as claimed in claim 3, additionally having a protective layer of inert mineral aggregate material imbedded in the top coating.
Claim 6
Dependent Claim
22 words
A built-up roofing structure as claimed in claim 4 in which the dispersed sulfur particle size averages from one to ten microns.
References Cited (Backward Citations)
US256368A
Cited
US1026855A
Cited
US2326724A
Cited
US2490430A
Cited
US3096196A
Cited
US3721578A
Cited
US3769078A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |