US4602082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Propylene-base random copolymer particles and production process thereof
Assignee: JAPAN STYRENE PAPER Corp A CORP OF JAPAN
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Filing: 1985-11-06
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Granted: 1986-07-22
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Expires: 2005-11-06
Abstract
Abstract Disclosed herein are propylene-base random copolymer particles suitable for use in the production of pre-foamed particles. The copolymer particles are obtained by heating starting copolymer particles to the crystallization temperature thereof and then quenching them in a medium of (the crystallization temperature-30 DEG C.) or lower. Processes for obtaining the copolymer particles are also disclosed. Pre-foamed particles produced using the copolymer particles contain large cells. They can thus provide foamed moldings which are substantially free of shrinkage and have good flexibility.
Inventors
- 👤 Hiroyuki Akiyama
- 👤 Susumu Izawa
- 👤 Hideki Kuwabara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:36
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/18; C08J3/00; C08J2203/00; C08J2203/14; C08J2203/142; C08J2323/00; C08J2323/02; C08J2323/10; Y; Y10; Y10S; Y10S264/00; Y10S264/09; Y10S264/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
89 words
A process for producing propylene-base random copolymer particles suitable for use in the production of pre-foamed particles, which comprises: charging starting propylene-base random copolymer particles together with a dispersing medium in a vessel; heating with stirring the contents to a temperature of the crystallization temperature of the starting copolymer particles or higher; and releasing the thus-heated starting copolymer particles and dispersing medium out of the vessel into a medium at a temperature of (the crystallization temperature -30° C.) or lower so as to quench the thus-heated starting copolymer particles.
Claim 2
Dependent Claim
89 words
A process for producing propylene-base random copolymer particles suitable for use in the production of pre-foamed particles, which comprises: charging starting propylene-base random copolymer particles together with a dispersing medium in a vessel; heating with stirring the contents to a temperature of the crystallization temperature of the starting copolymer particles or higher; and releasing the thus-heated starting copolymer particles and dispersing medium out of the vessel into a medium at a temperature of (the crystallization temperature -30° C.) or lower so as to quench the thus-heated starting copolymer particles.
Claim 3
Dependent Claim
33 words
A process according to claim 1, wherein the average volume of the starting propylene-base random copolymer particles, which are charged together with the dispersing medium in the vessel, is 0.03-4 mm 3 /particle.
Claim 4
Dependent Claim
20 words
A process according to claim 1 or 2, wherein the starting propylene-base random copolymer particles are ethylene-propylene random copolymer particles.
Claim 5
Dependent Claim
28 words
A process according to claim 3, wherein the starting propylene-base random copolymer particles are ethylene-propylene random copolymer particles in which the ethylene component amounts to 0.5-10 wt. %.
Claim 6
Dependent Claim
73 words
A process for producing propylene-base random copolymer particles suitable for use in the production of pre-foamed particles, which comprises the following steps: heating and melting a propylene-base random copolymer resin in an extruder; extruding the resultant melt through orifices of said extruder; quenching the resultant extrudates with a cooling medium at a temperature of (the crystallization temperature of propylene-base random copolymer resin -30° C.) or lower; and chopping the thus-quenched extrudates into particles.
Claim 7
Dependent Claim
73 words
A process for producing propylene-base random copolymer particles suitable for use in the production of pre-foamed particles, which comprises the following steps: heating and melting a propylene-base random copolymer resin in an extruder; extruding the resultant melt through orifices of said extruder; quenching the resultant extrudates with a cooling medium at a temperature of (the crystallization temperature of propylene-base random copolymer resin -30° C.) or lower; and chopping the thus-quenched extrudates into particles.
Claim 8
Dependent Claim
23 words
A process according to claim 5, wherein the quenched extrudates are chopped into particles having an average volume of 0.03-4 mm 3 /particle.
Claim 9
Dependent Claim
52 words
A process according to claim 5, wherein after extrusion of the heated and melted resin into strands through the orifices of the extruder, the strands are quenched with a cooling medium at a temperature of (the crystallization temperature -30° C.) or lower and then chopped into particles of 0.03-4 mm 3 /particle.
Claim 10
Dependent Claim
28 words
A process according to claim 7, wherein through the orifices of the extruder, the resin is extruded into strands having an average diameter of 1.7 mm or thinner.
Claim 11
Dependent Claim
56 words
A process according to claim 5, wherein the heated and melted resin is extruded through the orifices of the extruder into the cooling medium of (the crystallization temperature -30° C.) or lower while simultaneously chopping the resultant extrudates into particles of 0.03-4 mm 3 /particle, and the resultant particles are then quenched with the cooling medium.
Claim 12
Dependent Claim
12 words
A process according to claim 5, wherein the cooling medium is water.
Claim 13
Dependent Claim
17 words
A process according to claim 5, wherein the propylene-base random copolymer resin is an ethylene-propylene random copolymer.
Claim 14
Dependent Claim
26 words
A process according to claim 11, wherein the ethylene-propylene random copolymer is an ethylene-propylene random copolymer in which the ethylene component amounts to 0.5-10 wt. %.
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) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |