Patent US4038247A successfully refreshed from Google Patents.
US4038247A
Expired / Lapsed
US
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Stabilizing polyolefins with diacyl dihydrazides
Assignee: Novartis Corp
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Filing: 1975-06-13
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Granted: 1977-07-26
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Expires: 1995-06-13
Abstract
Abstract A process for stabilizing homo- or copolymeric polyolefins, especially polypropylene, with certain symmetrical or asymmetrical diacyl dihydrazides is disclosed, said diacyl dihydrazides possessing good color properties, and said process being particularly advantageous with respect to thermooxidative decomposition in the presence of transition metals.
Inventors
- 👤 Helmut Muller
- 👤 Siegfried Rosenberger
- 👤 Heimo Brunetti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:49
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/22; C08K5/24; C08K5/25
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
A process for stabilizing homo- or copolymeric polyolefins, characterised by incorporating into said material from 0.01 to 5 percent by weight, calculated on the material to be stabilized, of a compound of the formula ##STR34## wherein R and R' independently of each other represent an aralkyl group which is substituted in its aryl moiety by one or two alkyl groups having each from 1 to 4 carbon atoms and a hydroxyl group or a phenyl group which is substituted by one or two alkyl groups having each from 1 to 4 carbon atoms and a hydroxyl group and X represents the direct bond, an alkylene radical having from 2 to 8 carbon atoms, a phenylene radical or a naphthylene radical, and n represents 0 or 1.
Claim 2
Dependent Claim
126 words
A process for stabilizing homo- or copolymeric polyolefins, characterised by incorporating into said material from 0.01 to 5 percent by weight, calculated on the material to be stabilized, of a compound of the formula ##STR34## wherein R and R' independently of each other represent an aralkyl group which is substituted in its aryl moiety by one or two alkyl groups having each from 1 to 4 carbon atoms and a hydroxyl group or a phenyl group which is substituted by one or two alkyl groups having each from 1 to 4 carbon atoms and a hydroxyl group and X represents the direct bond, an alkylene radical having from 2 to 8 carbon atoms, a phenylene radical or a naphthylene radical, and n represents 0 or 1.
Claim 3
Dependent Claim
22 words
A process as claimed in claim 1, characterised by the use of the stabilizer, wherein R and R' is 3,5-di-tert.-butyl-4-hydroxy-β-phenylethyl or 3,5-di-tert.-butyl-4-hydroxyphenyl.
Claim 4
Dependent Claim
18 words
A process as claimed in claim 2 characterised by the use of the compound of the formula ##STR35##
Claim 5
Dependent Claim
10 words
A process of claim 1, wherein said polyolefin is polypropylene.
Claim 6
Dependent Claim
20 words
A composition of a homo- or copolymeric polyolefin containing 0.01 to 5% by weight of the stabilizer of claim 1.
Claim 7
Dependent Claim
10 words
A composition of claim 5 wherein said polyolefin is polypropylene.
Claim 8
Dependent Claim
13 words
A composition of claim 5, wherein R and R' are 3,5-di-tert-butyl-4-hydroxy-β-phenylethyl or 3,5-di-tert-butyl-4-hydroxyphenyl.
Claim 9
Dependent Claim
10 words
A composition of claim 7, wherein the stabilizer is ##STR36##
References Cited (Backward Citations)
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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) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |