US4298394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic gypsum set accelerators
Assignee: BPB Ltd
•
Filing: 1979-06-28
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Granted: 1981-11-03
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Expires: 1999-06-28
Abstract
Abstract A gypsum set accelerator for use in the production of gypsum wallboard comprises a tube or ball milled mixture of gypsum and up to 20 percent by weight of the gypsum of a synthetic water-soluble solid surfactant. A process for the manufacture of gypsum wallboard is also described comprising spreading between paper sheets an aqueous slurry of calcium sulphate hemihydrate defined above at a rate of between 0.5 and 15 kilograms per 100 square meters (1 and 30 pounds per 1000 square feet) of gypsum wallboard, and allowing the slurry to set. The accelerator has high potency and appears to provide wallboard of increased compressive strength.
Inventors
- 👤 Peter A. Leeming
- 👤 Dimitrios Mitakidis
- 👤 Peter F. Woodrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:23
CPC Classifications
C; C04; C04B; C04B40/00; C04B40/0028; C04B40/0039; C04B28/00; C04B28/14; C04B2103/00; C04B2103/10; C04B2103/12; C04B2103/40; C04B2111/00; C04B2111/00474; C04B2111/00612; C04B2111/0062; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
38 words
A gypsum set accelerator for use in the production of gypsum wallboard comprising gypsum incorporating an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 2
Dependent Claim
38 words
A gypsum set accelerator for use in the production of gypsum wallboard comprising gypsum incorporating an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 3
Dependent Claim
14 words
An accelerator according to claim 1 wherein the detergent is a synthetic anionic detergent.
Claim 4
Dependent Claim
19 words
An accelerator according to claim 2 wherein the detergent is a solid sodium alkylate sulphonate or sodium lauryl sulphate.
Claim 5
Dependent Claim
14 words
An accelerator according to claim 3 wherein the detergent is a linear alkylbenzene sulphonate.
Claim 6
Dependent Claim
14 words
An accelerator according to claim 4 wherein the detergent is sodium linear alkylbenzene sulphonate.
Claim 7
Dependent Claim
17 words
An accelerator according to claim 5 wherein the detergent is a sodium salt of dodecyl benzene sulphonate.
Claim 8
Dependent Claim
14 words
An accelerator according to claim 1 wherein the detergent is a synthetic non-ionic detergent.
Claim 9
Dependent Claim
13 words
An accelerator according to claim 7 wherein the detergent is an ethoxylated nonyl-phenol.
Claim 10
Dependent Claim
24 words
An accelerator according to any of claims 1 to 8 having a specific surface area-to-weight ratio of at least 8000 square centimeters per gram
Claim 11
Independent Claim
38 words
A method of making a gypsum set accelerator which comprises milling together gypsum and at least one solid water-soluble synthetic detergent in an effective set accelerating increasing amount up to 20 percent of the weight of the gypsum.
Claim 12
Independent Claim
38 words
A method of making a gypsum set accelerator which comprises milling together gypsum and at least one solid water-soluble synthetic detergent in an effective set accelerating increasing amount up to 20 percent of the weight of the gypsum.
Claim 13
Dependent Claim
85 words
A process for the manufacture of gypsum wallboard which comprises spreading an aqueous slurry of calcium sulphate hemihydrate between two parallel continuous paper sheets and allowing the gypsum to set, wherein there is added to the hemihydrate at a rate of between 0.5 and 15 kilograms per 100 square meters of gypsum wallboard an accelerator comprising a milled composition of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 14
Dependent Claim
85 words
A process for the manufacture of gypsum wallboard which comprises spreading an aqueous slurry of calcium sulphate hemihydrate between two parallel continuous paper sheets and allowing the gypsum to set, wherein there is added to the hemihydrate at a rate of between 0.5 and 15 kilograms per 100 square meters of gypsum wallboard an accelerator comprising a milled composition of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 15
Dependent Claim
23 words
A process according to claim 11 wherein the detergent is a solid sodium linear alkylbenzene sulphonate, sodium lauryl sulphate or solid ethoxylated nonyl-phenol.
Claim 16
Dependent Claim
43 words
A gypsum set accelerator for use in the production of gypsum wallboard comprising a dry milled admixture of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 17
Dependent Claim
43 words
A gypsum set accelerator for use in the production of gypsum wallboard comprising a dry milled admixture of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 18
Dependent Claim
45 words
A gypsum set accelerator for use in the production of gypsum wallboard consisting essentially of a dry milled admixture of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 19
Dependent Claim
45 words
A gypsum set accelerator for use in the production of gypsum wallboard consisting essentially of a dry milled admixture of gypsum and an effective set accelerating increasing amount up to 20 percent by weight of the gypsum of at least one synthetic solid water-soluble detergent.
Claim 20
Dependent Claim
23 words
An accelerator according to claim 1, wherein said synthetic detergent is selected from the group consisting of anionic, non-ionic and cationic synthetic detergents.
Claim 21
Dependent Claim
23 words
An accelerator according to claim 13, wherein said synthetic detergent is selected from the group consisting of anionic, non-ionic and cationic synthetic detergents.
Claim 22
Dependent Claim
23 words
An accelerator according to claim 14, wherein said synthetic detergent is selected from the group consisting of anionic, non-ionic and cationic synthetic detergents.
Claim 23
Dependent Claim
19 words
An accelerator according to claim 15, wherein said accelerator is a milled admixture of said gypsum and said detergent.
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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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |