Patent US3971785A successfully refreshed from Google Patents.
US3971785A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of flowed-in aerosol can gaskets
Assignee: WR Grace and Co
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Filing: 1975-02-13
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Granted: 1976-07-27
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Expires: 1995-02-13
Abstract
Abstract Process of lining aerosol can valve mounting cups with a gasketing composition comprising a carbon dioxide blocked polyamine dispersed in a liquid polyurethane prepolymer consisting of a free isocyanate group-containing reaction product of a polyisocyanate compound with a polyhydroxy material. The lined cups are heated for a few minutes to gel the gasket and full cure subsequently takes place without further intervention by means of ambient atmospheric moisture. The process is rapid, economical in equipment and produces gaskets which permit a significant extension of swaging specifications.
Inventors
- 👤 Thomas A. Messina
- 👤 Patrick J. Droney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:51
CPC Classifications
B; B65; B65D; B65D83/00; B65D83/14; B65D83/38; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; Y; Y10; Y10S; Y10S264/00; Y10S264/59
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
118 words
A method for lining an aerosol can mounting cup with a sealing gasket consisting of: a. depositing in the annular channel of the mounting cup a layer of a composition comprising (1) a liquid prepolymer of a free isocyanate groups-containing reaction product of a polyisocyanate with a polyhydroxy compound and (2) a finely divided carbon dioxide blocked polyamine; b. heating the cup and said composition deposited therein to a temperature sufficient to cause decomposition of said polyamine with time, but said heating being for a time sufficient to gel said composition only and insufficient to cause substantial decomposition of said polyamine; and c. then allowing said composition to cure further at ambient temperature in an atmosphere containing moisture.
Claim 2
Independent Claim
118 words
A method for lining an aerosol can mounting cup with a sealing gasket consisting of: a. depositing in the annular channel of the mounting cup a layer of a composition comprising (1) a liquid prepolymer of a free isocyanate groups-containing reaction product of a polyisocyanate with a polyhydroxy compound and (2) a finely divided carbon dioxide blocked polyamine; b. heating the cup and said composition deposited therein to a temperature sufficient to cause decomposition of said polyamine with time, but said heating being for a time sufficient to gel said composition only and insufficient to cause substantial decomposition of said polyamine; and c. then allowing said composition to cure further at ambient temperature in an atmosphere containing moisture.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said heating temperature is under 200°F and said heating time is about 2 minutes.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the polyhydroxy compound is a mixture of at least one diol and one triol, said triol constituting at least 30% of the mixture by weight.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the polyamine is a triamine and the polyisocyanate is aromatic or alicyclic.
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) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |