US3676541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal casting method
Assignee: Taiheiyo Cement Corp
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Filing: 1970-09-08
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Granted: 1972-07-11
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Expires: 1990-09-08
Abstract
Abstract This invention relates to a method of making mortar or concrete pipes by centrifugal casting. The method is characterized by using mortar or concrete prepared from a cementiteous material incorporated with a salt of Beta -naphthalenesulfonic acidformaldehyde condensate, and curing the mortar or concrete pipes made by the above condition with high pressure steam in an autoclave.
Inventors
- 👤 Selya Nishi
- 👤 Akira Oshio
- 👤 Kiyomitsu Eto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:07
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
19 words
The method of claim 1 wherein said salt is selected from the group consisting of sodium and calcium salts.
Claim 2
Dependent Claim
26 words
The method of claim 1 wherein said condensate comprises at least 70 percent Condensation polymers having at least five Beta -naphthalenesulfonic acid units in a molecule.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said salt is present in an amount of from 0.8 to 1.2 by weight based on the cementitious material.
Claim 4
Dependent Claim
40 words
The method of claim 1 wherein said cementitious material is selected from the group consisting of Portland cement and mixtures of Portland cement and a material selected from the group consisting of fine silica, fly ash, and blast furnace slag.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said cast pipes are subjected to high pressure steam curing in an autoclave.
Claim 6
Dependent Claim
79 words
In a method of making cementitious pipe by centrifugal casting, the improvement which comprises adding from 0.2 to 1.5 percent by weight of a salt of a Beta -naphthalenesulfonic acid-formaldehyde condensate and from 0.03 to 2 percent by weight of any member selected from the group consisting of carboxylic acids, hydroxy carboxylic acids, derivatives thereof, and alkali and alkaline earth metal salts thereof, to the cementitious material prior to casting, the weight percent being based on the cementitious material.
Claim 7
Dependent Claim
26 words
The method of claim 7 wherein said condensate comprises at least 70 percent condensation polymers having at least five Beta -naphthalenesulfonic acid units in a molecule.
Claim 8
Dependent Claim
21 words
The method of claim 7 wherein said condensate is present in an amount of from 0.4 to 1.2 percent by weight.
Claim 9
Dependent Claim
20 words
The method of claim 7 wherein said member is present in an amount from 0.06 to 0.15 percent by weight.
Claim 10
Dependent Claim
21 words
The method of claim 10 wherein said condensate is present in an amount of from 0.4 to 1.2 percent by weight.
Claim 11
Dependent Claim
38 words
The process of claim 7 wherein said member is selected from the group consisting of lactic acid, gluconic acid, adipic acid, succinic acid, malleic acid, heptanedioic acid, and alkali metal salts, alkaline earth metal salts and derivatives thereof.
Claim 12
Dependent Claim
23 words
The method of claim 12 wherein said condensate comprises at least 70 percent condensation polymers having at least five Beta -napthalenesulfonic acid units.
Claim 13
Dependent Claim
17 words
The method of claim 13 wherein the member is a sodium salt of an adipic acid derivative.
Claim 14
Dependent Claim
11 words
The method of claim 13 wherein the member is calcium lactate.
Claim 15
Dependent Claim
19 words
The method of claim 7 wherein the cast pipes are subjected to high pressure steam curing in an autoclave.
References Cited (Backward Citations)
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Cited
US1972208A
Cited
US2141571A
Cited
US2499445A
Cited
US2690975A
Cited
US3277162A
Cited
US3465825A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |