US4769397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical blowing agent compositions
Assignee: Enron Chemical Co
•
Filing: 1986-09-18
•
Granted: 1988-09-06
•
Expires: 2006-09-18
Abstract
Abstract A method of making a foam injection molded article is disclosed wherein corrosion of the mold element is significantly reduced or substantially eliminated. The method comprises dispersing effective amounts of a primary chemical blowing agent of sodium borohydride and an activation system of sodium bicarbonate/citric acid mix into a polymer resin to form a mixture. The mixture is then heated whereby the activation system releases water and the sodium borohydride reacts with the water to produce hydrogen gas. The mixture is subsequently injected into a mold to obtain expansion of the polymer resin to form the foam article. The invention also comprehends a corresponding chemical blowing agent composition.
Inventors
- 👤 Robert M. Lapierre
- 👤 Nicholas J. Leonardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:30
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/065; C08J9/08; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/14; Y10S264/83
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A foamable polymeric composition comprising: an effective amount of a primary chemical blowing agent consisting essentially of sodium borohydride and no more than about 8 parts by weight, per part by weight of said sodium borohydride, of an activation system comprising a first mixture of effective amounts of sodium bicarbonate and citric acid, each of said sodium borohydride and said activation system being dispersed in a polymer resin to be foamed to form a second mixture with said sodium borohydride comprising about 0.01-5 wt % of said second mixture, said sodium borohydride and said activation system being isolated from direct contact with each other until gas production is desired.
Claim 2
Dependent Claim
109 words
A foamable polymeric composition comprising: an effective amount of a primary chemical blowing agent consisting essentially of sodium borohydride and no more than about 8 parts by weight, per part by weight of said sodium borohydride, of an activation system comprising a first mixture of effective amounts of sodium bicarbonate and citric acid, each of said sodium borohydride and said activation system being dispersed in a polymer resin to be foamed to form a second mixture with said sodium borohydride comprising about 0.01-5 wt % of said second mixture, said sodium borohydride and said activation system being isolated from direct contact with each other until gas production is desired.
Claim 3
Dependent Claim
21 words
The composition of claim 1 wherein said first mixture comprises an approximately equimolar mixture of said citric acid and sodium bicarbonate.
Claim 4
Dependent Claim
25 words
The composition of claim 1 wherein about 5 parts by weight of said first mixture are present per part by weight of said sodium borohydride.
Claim 5
Dependent Claim
18 words
The composition of claim 1, wherein said sodium borohydride comprises about 0.1-0.3 wt % of said second mixture.
Claim 6
Dependent Claim
23 words
The composition of claim 1 wherein said sodium borohydride and said first mixture are each encapsulated in a carrier resin prior to heating.
Claim 7
Dependent Claim
22 words
The composition of claim 5 wherein said carrier resin is a polymer selected from the group consisting of polyethylene, polystyrene, and polypropylene.
Claim 8
Dependent Claim
20 words
The composition of claim 6 wherein said sodium borohydride comprises approximately 10 wt % of said polymer encapsulated sodium borohydride.
Claim 9
Dependent Claim
23 words
The composition of claim 6 wherein said sodium bicarbonate and citric acid comprise approximately 50 wt % of said polymer encapsulated first mixture.
Claim 10
Dependent Claim
53 words
The composition of claim 5 adapted for use in foaming a polymer resin wherein said composition is dispersed in a polymer resin to be foamed with about 0.2-3 parts by weight of said carrier encapsulated sodium borohydride and said carrier encapsulated first mixture present per 100 parts by weight of said polymer resin.
Claim 11
Dependent Claim
34 words
The composition of claim 9 wherein about 2 parts by weight of said carrier encapsulated sodium borohydride and said carrier encapsulated first mixture are present per 100 parts by weight of said polymer resin.
References Cited (Backward Citations)
US2941964A
Cited
US3185588A
Cited
US4394458A
Cited
US4397948A
Cited
US4399238A
Cited
US4431752A
Cited
US4403045A
Cited
US4383048A
Cited
US4413065A
Cited
US4520137A
Cited
US4588754A
Cited
US4650816A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |