Patent US3846349A successfully refreshed from Google Patents.
US3846349A
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US
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Polypropylene composition and foamed polypropylene sheet therefrom
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1973-06-26
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Granted: 1974-11-05
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Expires: 1993-06-26
Abstract
Abstract A polypropylene composition consisting essentially of from 30 to 80 parts by weight of a crystalline polypropylene, from 10 to 40 parts by weight of a non-crystalline polypropylene, and from 10 to 40 parts by weight of a low density polyethylene. A foamed polypropylene sheet made of the polypropylene composition has excellent impact resistance and a good texture.
Inventors
- 👤 T Harada
- 👤 N Ito
- 👤 K Ohishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:58
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505; C08J9/04; C08J9/06; C08J9/10; C08J9/12; B29K; B29K2023/00; B29L; B29L2007/00; C08J2323/00; C08J2323/02; C08J2423/00; Y; Y10; Y10S; Y10S521/00; Y10S521/91
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
73 words
A FOAMED POLYPROPYLENE SHEET HAVING EXCELLENT IMPACT RESISTANCE AND A GOOD TEXTURE AND BEING SOFT, WHICH IS OBTAINED BY ADDING A BLOWING AGENT TO A POLYPROPYLENE COMPOSITION CONSISTING ESSENTIALLY OF FROM 30 TO 80 PARTS BY WEIGHT OF A CRYSTALLINE POLYPROPYLENE, FROM 10 TO 40 PARTS BY WEIGHT OF A NON-CRYSTALLINE POLYPROPYLENE AND FROM 10 TO 40 PARTS BY WEIGHT OF A LOW DENSITY POLYETHYLENE AND THEN EXTRUDING THE RESULTING MIXTURE TO FOAM.
Claim 2
Dependent Claim
73 words
A FOAMED POLYPROPYLENE SHEET HAVING EXCELLENT IMPACT RESISTANCE AND A GOOD TEXTURE AND BEING SOFT, WHICH IS OBTAINED BY ADDING A BLOWING AGENT TO A POLYPROPYLENE COMPOSITION CONSISTING ESSENTIALLY OF FROM 30 TO 80 PARTS BY WEIGHT OF A CRYSTALLINE POLYPROPYLENE, FROM 10 TO 40 PARTS BY WEIGHT OF A NON-CRYSTALLINE POLYPROPYLENE AND FROM 10 TO 40 PARTS BY WEIGHT OF A LOW DENSITY POLYETHYLENE AND THEN EXTRUDING THE RESULTING MIXTURE TO FOAM.
Claim 3
Dependent Claim
28 words
The sheet according to claim 1, wherein the blowing agent is a member selected from the group consisting of a chemical blowing agent and a volatile expansion agent.
Claim 4
Dependent Claim
29 words
The sheet according to claim 1, wherein the mixture is extruded at a resin temperature of 150* to 250*C and at a resin pressure of 50 to 350 kg/cm2.
Claim 5
Dependent Claim
17 words
The Sheet according to claim 1, wherein the sheet has a foaming ratio of 1.1 to 2.0.
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) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |