US3876566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method producing foamed thermoplastic compositions
Assignee: Standard Oil Co
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Filing: 1972-11-13
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Granted: 1975-04-08
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Expires: 1992-11-13
Abstract
Abstract Improved foamed or cellular thermoplastic articles are obtained by incorporating in a conventional recipe for producing such articles a compound of the formula R--CO--NH--NH--CO--(CH.sub.2) .sub.n --CO--NH--NH--CO--R'', where R and R'' independently are alkyl groups containing up to 4 carbon atoms and n is an integer of 1 to 8, the addition of said compound serving to produce a cellular article of reduced specific gravity. An example of a specific additive found to have good results is N, N''-diacetyladipic dihydrazide, sometimes referred to as N, N''diethanoyladipic dihydrazide. Foamed articles produced by the process disclosed have lower specific gravities than obtained with prior art additives.
Inventors
- 👤 James A Koshak
- 👤 William R Mcguire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:34
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/307; C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08J9/102; C08J9/103; C08J9/104; C08J9/105; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/91
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
94 words
IN THE PRODUCTION OF CELLULAR THERMOPLASTIC ARTICLES WHEREIN THE THERMOPLASTIC RESIN IS MIXED WITH A BLOWING AGENT AND HEATED TO ACTIVATE SAID BLOWING AGENT, THE IMPROVEMENT COMPRISING INCORPORATING IN SAID RESIN IN THE AMOUNT OF 0.05 TO 0.6 WEIGHT PERCENT BASED ON THE RESIN, A DIHYDRAZIDE OF THE FORMULA R-CO-NH-NH-CO-(CH2)N-CO-NH-NH-CO-R'', WHERE R AND R'' INDEPENDENTLY ARE ALKYL GROUPS CONTAINING UP TO 4 CARBON ATOMS AND N IS AN INTEGER OF 1 TO 8, THE ADDITION OF SAID DIHYDRAZIDE SERVING TO PRODUCE A CELLULAR ARTICLE OF REDUCED SPECIFIC GRAVITY AT A GIVEN BLOWING AGENT LEVEL.
Claim 2
Dependent Claim
94 words
IN THE PRODUCTION OF CELLULAR THERMOPLASTIC ARTICLES WHEREIN THE THERMOPLASTIC RESIN IS MIXED WITH A BLOWING AGENT AND HEATED TO ACTIVATE SAID BLOWING AGENT, THE IMPROVEMENT COMPRISING INCORPORATING IN SAID RESIN IN THE AMOUNT OF 0.05 TO 0.6 WEIGHT PERCENT BASED ON THE RESIN, A DIHYDRAZIDE OF THE FORMULA R-CO-NH-NH-CO-(CH2)N-CO-NH-NH-CO-R'', WHERE R AND R'' INDEPENDENTLY ARE ALKYL GROUPS CONTAINING UP TO 4 CARBON ATOMS AND N IS AN INTEGER OF 1 TO 8, THE ADDITION OF SAID DIHYDRAZIDE SERVING TO PRODUCE A CELLULAR ARTICLE OF REDUCED SPECIFIC GRAVITY AT A GIVEN BLOWING AGENT LEVEL.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the blowing agent is p,p''-oxybis (benzene sulfonyl hydrazide) or azodicarbonamide.
Claim 4
Dependent Claim
37 words
The process of claim 1 wherein said resin is polypropylene or poly (vinyl chloride) and said dihydrazide is N,N''-diacetyl-adipic dihydrazide, the latter being present in an amount of 0.05 to 0.6 weight percent based on the resin.
Claim 5
Dependent Claim
33 words
The process of claim 1 wherein said resin is polypropylene and said dihydrazide is N,N''-diacetyl-adipic dihydrazide, the latter being present in an amount of 0.05 to 0.3 weight percent based on the resin.
Claim 6
Dependent Claim
35 words
The process of claim 1 wherein said resin is poly (vinyl chloride) and said dihydrazide is N,N''-diacetyl-adipic dihydrazide, the latter being present in an amount of 0.05 to 0.3 weight percent based on the resin.
Claim 7
Independent Claim
79 words
A method of producing cellular insulation on wire which comprises incorporating 0.05 to 0.3 percent by weight of N,N''-diacetyl-adipic dihydrazide into a block polymer composition containing a polypropylene polymer having an ethylene/propylene copolymer block attached, coating the blend with an effective amount of a blowing agent, and extruding the mixture in a wire coating machine at a temperature in the range of 375.degree. to 450.degree.F. to produce a coated wire, said coating being cellular polymer of low specific gravity.
Claim 8
Independent Claim
79 words
A method of producing cellular insulation on wire which comprises incorporating 0.05 to 0.3 percent by weight of N,N''-diacetyl-adipic dihydrazide into a block polymer composition containing a polypropylene polymer having an ethylene/propylene copolymer block attached, coating the blend with an effective amount of a blowing agent, and extruding the mixture in a wire coating machine at a temperature in the range of 375.degree. to 450.degree.F. to produce a coated wire, said coating being cellular polymer of low specific gravity.
Claim 9
Dependent Claim
11 words
The method of claim 6 wherein said blowing agent is azodicarbonamide.
Claim 10
Independent Claim
48 words
A method of producing cellular poly (vinyl chloride) resin which comprises incorporating 0.05 to 0.3 percent by weight of N,N''-diacetyl-adipic dihydrazide into said resin, coating the blend with an effective amount of a blowing agent, and extruding the composition to produce a cellular product of low specific gravity.
Claim 11
Independent Claim
48 words
A method of producing cellular poly (vinyl chloride) resin which comprises incorporating 0.05 to 0.3 percent by weight of N,N''-diacetyl-adipic dihydrazide into said resin, coating the blend with an effective amount of a blowing agent, and extruding the composition to produce a cellular product of low specific gravity.
Claim 12
Dependent Claim
19 words
The process of claim 8 wherein said blowing agent is a mixture of azodicarbonamide and p,p''-oxybis (benzene sulfonyl hydrazide).
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |