US3933515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal shock resistant asbestos-cement compositions and their preparation
Assignee: Johns Manville Corp
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Filing: 1974-09-06
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Granted: 1976-01-20
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Expires: 1994-09-06
Abstract
Abstract A thermal shock resisting asbestos-cement composition is prepared by adding a finely divided porosity increasing additive as a partial or complete replacement for silica flour in an asbestos-cement composition containing asbestos fibers, portland cement, and silica flour. The composition is shaped and cured to form the final thermal shock resistant product.
Inventors
- 👤 Julie Chi-Sun Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:14
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
A thermal shock resistant asbestos-cement composition consisting essentially of the following ingredients, in percentage by weight on a dry solids basis: a. 10 to 50% asbestos fibers; b. silica in a percentage in the range of 20 to 40% less the percentage of the organic porosity-enhancing additive of (d) below; c. 25 to 65% hydraulic cement; and d. 1 to 30% of an organic fibrous porosity-enhancing additive selected from the group consisting of nylon fibers, orlon fibers and sisal fibers, said additive being of the type which will prevent surface cracking of a product made of said composition when said product is saturated with water and then subjected to temperatures on the order of 700°C for a period of one hour.
Claim 2
Dependent Claim
121 words
A thermal shock resistant asbestos-cement composition consisting essentially of the following ingredients, in percentage by weight on a dry solids basis: a. 10 to 50% asbestos fibers; b. silica in a percentage in the range of 20 to 40% less the percentage of the organic porosity-enhancing additive of (d) below; c. 25 to 65% hydraulic cement; and d. 1 to 30% of an organic fibrous porosity-enhancing additive selected from the group consisting of nylon fibers, orlon fibers and sisal fibers, said additive being of the type which will prevent surface cracking of a product made of said composition when said product is saturated with water and then subjected to temperatures on the order of 700°C for a period of one hour.
Claim 3
Dependent Claim
11 words
The composition of claim 1 further consisting essentially of a hydromodifier.
Claim 4
Dependent Claim
17 words
The composition of claim 1 wherein said additive is present as 1 to 5% of said admixture.
Claim 5
Dependent Claim
139 words
A process for the formation of a thermal shock resistant asbestos-cement product which comprises: a. forming an aqueous admixture of, in percentage by weight on a dry solids basis: i. 10 to 50% asbestos fibers; ii. silica in a percentage in the range of 20 to 40% less the percentage of the organic porosity-enhancing additive of (iv) below; iii. 25 to 65% hydraulic cement; and iv. 1 to 30% of an organic fibrous porosity-enhancing additive consisting of nylon fibers, orlon fibers and sisal fibers, said additive being of the type which will prevent surface cracking of said product when said product is saturated with water and then subjected to temperatures on the order of 700°C for a period of one hour, b. shaping said admixture to form a shaped body; and c. curing said body to produce said product.
Claim 6
Dependent Claim
139 words
A process for the formation of a thermal shock resistant asbestos-cement product which comprises: a. forming an aqueous admixture of, in percentage by weight on a dry solids basis: i. 10 to 50% asbestos fibers; ii. silica in a percentage in the range of 20 to 40% less the percentage of the organic porosity-enhancing additive of (iv) below; iii. 25 to 65% hydraulic cement; and iv. 1 to 30% of an organic fibrous porosity-enhancing additive consisting of nylon fibers, orlon fibers and sisal fibers, said additive being of the type which will prevent surface cracking of said product when said product is saturated with water and then subjected to temperatures on the order of 700°C for a period of one hour, b. shaping said admixture to form a shaped body; and c. curing said body to produce said product.
Claim 7
Dependent Claim
17 words
The composition of claim 4 wherein said additive is present as 1 to 5% of said admixture.
Claim 8
Dependent Claim
14 words
The process of claim 4 wherein said curing step comprises autoclaving said shaped body.
Claim 9
Dependent Claim
12 words
The process of claim 4 wherein said admixture further comprises a hydromodifier.
Claim 10
Dependent Claim
13 words
The process of claim 7 wherein said shaping step comprises extruding said admixture.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |