US4407768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foamable polymeric composition comprising propylene polymer and hydrated alumina
Assignee: Phillips Petroleum Co
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Filing: 1982-01-08
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Granted: 1983-10-04
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Expires: 2002-01-08
Abstract
Abstract Compositions comprising propylene polymer, e.g., polypropylene, and hydrated alumina as filler precursor and sole blowing agent, wherein the alumina can be 30 to 60 weight percent of the total composition, are converted into foam having a fine and uniform cellular structure by passage through an unvented extruder at specified temperature profiles and pressures.
Inventors
- 👤 Rodrigo A. Garcia
- 👤 Roel Moreno
- 👤 Robert J. Martinovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:34
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/125; C08J9/0066; C08J2323/00; C08J2323/02; C08J2323/10; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/16; Y10S521/00; Y10S521/907
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
82 words
A foamable thermoplastic composition comprising a propylene polymer selected from the group of resinous homopolymers of propylene and copolymers of propylene copolymerized with a minor amount of one or more comonomers selected from the group consisting of aliphatic mono-1-olefins containing from 2 to about 10 carbon atoms, said composition having dispersed therein a filler precursor and sole blowing agent being particulate hydrated alumina of the formula Al 2 O 3 .xH 2 O, wherein x has any value from 1 to 3.
Claim 2
Dependent Claim
82 words
A foamable thermoplastic composition comprising a propylene polymer selected from the group of resinous homopolymers of propylene and copolymers of propylene copolymerized with a minor amount of one or more comonomers selected from the group consisting of aliphatic mono-1-olefins containing from 2 to about 10 carbon atoms, said composition having dispersed therein a filler precursor and sole blowing agent being particulate hydrated alumina of the formula Al 2 O 3 .xH 2 O, wherein x has any value from 1 to 3.
Claim 3
Dependent Claim
36 words
A composition in accordance with claim 1 wherein said homopolymer has a melt flow in the range of from about 0.5 to 50 and a density of about 0.9 to 0.91 grams per cm 3 .
Claim 4
Dependent Claim
20 words
A composition in accordance with claim 1 wherein said copolymer comprises from 98 to 99.9 weight percent polymerized propylene units.
Claim 5
Dependent Claim
13 words
A composition in accordance with claim 1 wherein said aliphatic mono-1-olefin is ethylene.
Claim 6
Dependent Claim
18 words
A composition in accordance with claim 4 wherein said copolymer is a random copolymer of propylene and ethylene.
Claim 7
Dependent Claim
19 words
A composition in accordance with claim 1 wherein said copolymer is a random copolymer of propylene and a comonomer.
Claim 8
Dependent Claim
26 words
A composition in accordance with claim 1 wherein said filler precursor and blowing agent is from about 30 to about 60 weight percent of said composition.
Claim 9
Dependent Claim
25 words
A composition in accordance with claim 1 wherein said filler precursor and blowing agent is from about 35 to 45 weight percent of said composition.
Claim 10
Dependent Claim
76 words
A process for preparing a foamed plastic material which comprises heating a foamable composition in accordance with one of the claims 1 to 8 to a temperature above the melting temperature, but below the decomposition temperature, of said propylene polymer and above the dehydration temperature of said hydrated alumina, such that at least part of the water of hydration of said alumina is released to act as a blowing agent, and subsequently cooling the foamed composition.
Claim 11
Dependent Claim
40 words
A process in accordance with claim 9 wherein said composition is heated in a nonvented extruder having a temperature profile decreasing from a maximum at the feed zone to a minimum where the foamed composition exits and is extruded therefrom.
Claim 12
Dependent Claim
41 words
A process in accordance with claim 10 wherein said extruder has a temperature profile decreasing from about 260° C. to about 145° C., producing a maximum back pressure in said extruder in the range of about 900 to about 2500 psig.
Claim 13
Dependent Claim
31 words
A process for extruding or molding an article of foamed plastic material, comprising extruding or molding a composition in accordance with one of claims 1-8 in an extrusion or molding apparatus.
Claim 14
Dependent Claim
16 words
A process in accordance with claim 12 wherein said molding apparatus is an injection molding machine.
Claim 15
Dependent Claim
14 words
A process in accordance with claim 12 wherein said composition is formed into sheets.
Claim 16
Dependent Claim
20 words
A process in accordance with claim 12 wherein said composition is extruded in a shape of a desired cross section.
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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) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |