US4440703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing foamed and molded article of polypropylene resin
Assignee: JAPAN STYRENE PAPER Corp A CORP OF JAPAN
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Filing: 1982-08-04
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Granted: 1984-04-03
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Expires: 2002-08-04
Abstract
Abstract A process for producing a foamed and molded article of a polypropylene resin, which comprises pressurizing preliminarily-foamed particles of an ethylene/propylene copolymer having a melt index value of from 0.1 to 25, a latent heat of crystallization of not more than 28 cal/g and an ethylene content of from 1 to 30% by weight as a base resin with an inorganic gas or a gaseous mixture of the inorganic gas and a volatile blowing agent thereby to impart an elevated pressure to the inside of said particles, thereafter filling said particles in a mold capable of enclosing the particles but allowing escape of gases therefrom, and then heating said particles to expand them to the configuration of the mold.
Inventors
- 👤 Hiroyuki Akiyama
- 👤 Kuninori Hirosawa
- 👤 Hideki Kuwabara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:36
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/22; C08J9/228; C08J9/232; B; B29; B29K; B29K2023/00; B29K2023/10; B29K2023/12; C08J2323/00; C08J2323/02; C08J2323/16; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/15; Y10S264/16
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
144 words
A process for producing a foamed and molded article of a polypropylene resin, which comprises pressurizing preliminarily-foamed particles of a non-crosslinked ethylene/propylene copolymer having a melt index value of from 0.1 to 25, a latent heat of crystallization of not more than 28 cal/g and an ethylene content of from 1 to 30% by weight as a base resin with an inorganic gas or a gaseous mixture of the inorganic gas and a volatile blowing agent whereby the inorganic gas or the gaseous mixture penetrates into said particles and impart an elevated pressure in the range of 0.5 to 5 kg/cm 2 (G) to the inside of said particles, thereafter filling said particles in a perforated mold capable of enclosing the particles but allowing escape of gases therefrom, and then heating said particles with steam to expand them to the configuration of the mold.
Claim 2
Dependent Claim
144 words
A process for producing a foamed and molded article of a polypropylene resin, which comprises pressurizing preliminarily-foamed particles of a non-crosslinked ethylene/propylene copolymer having a melt index value of from 0.1 to 25, a latent heat of crystallization of not more than 28 cal/g and an ethylene content of from 1 to 30% by weight as a base resin with an inorganic gas or a gaseous mixture of the inorganic gas and a volatile blowing agent whereby the inorganic gas or the gaseous mixture penetrates into said particles and impart an elevated pressure in the range of 0.5 to 5 kg/cm 2 (G) to the inside of said particles, thereafter filling said particles in a perforated mold capable of enclosing the particles but allowing escape of gases therefrom, and then heating said particles with steam to expand them to the configuration of the mold.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the ethylene/propylene copolymer is a random copolymer, a block copolymer, or a mixture of these.
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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) | 1987-04-03 | 1987-10-03 | 1988-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-03 | 1991-10-03 | 1992-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-03 | 1995-10-03 | 1996-04-03 | $7700.00 | Window Closed / Lapsed |