US4510292A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ethylene-propylene copolymers for foaming and process for producing the same
Assignee: JNC Corp
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Filing: 1983-08-11
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Granted: 1985-04-09
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Expires: 2003-08-11
Abstract
Abstract An ethylene-propylene block copolymer capable of producing foamed shaped articles having a structure of uniform and fine foams even without adding any other resins, and a process for producing the same are provided, which copolymer consists of a propylene homopolymer portion and an ethylene-propylene (EP) copolymer portion and is characterized in that ○1 the former portion is obtained by polymerizing propylene at two stages so that the portion can further consist of a lower molecular weight portion and a higher molecular portion; ○2 between the melt flow rates of the resulting block copolymer under a specified load and five times the load, there is a specified relationship; ○3 the EP copolymer portion has an ethylene content of 60 to 95% by weight based on this portion; and ○4 the block copolymer has an ethylene content of 10 to 40% by weight based on the copolymer.
Inventors
- 👤 Hiromasa Chiba
- 👤 Kenjiro Obama
- 👤 Shunji Kawazoe
- 👤 Takahiro Oka
- 👤 Akihiro Satoh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:37
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/06; C08F297/08; C08F297/083; C08L; C08L23/00; C08L23/02; C08L23/10; C08L2205/00; C08L2205/02; C08L23/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
306 words
In a process for producing a block copolymer by copolymerizing propylene with ethylene in the presence of a catalyst comprising a titanium trichloride composition and an organoaluminum compound and a molecular weight modifier, the improvement which comprises: (a) polymerizing propylene in two steps so that the resulting propylene homopolymer portion will consist of a lower molecular weight portion and a higher molecular weight portion, the intrinsic viscosity [η] H of said higher molecular portion and the intrinsic viscosity [η] L of said lower molecular weight portion having the relationship expressed by the following equation: 3.5≦[η].sub.H -[η].sub.L ≦7.0 said propylene homopolymerization is carried out so that the proportions of said lower molecular weight portion and said higher molecular weight portion are 40 to 60% and 60 to 40% by weight, respectively, (b) in a subsequent stage copolymerizing ethylene with propylene, in the presence of said propylene homopolymer portion, into a block copolymer consisting of said propylene homopolymer portion and an ethylene-propylene copolymer portion, the ethylene being polymerized with propylene so that the molecular weight of said ethylene-propylene copolymer portion will have a value between the molecular weights of said lower molecular weight portion and said higher molecular portion in said propylene homopolymer portion, and so that ethylene-propylene copolymer portion will have an ethylene content of 60-95% by weight based on said copolymer portion, and (c) controlling the amounts of the respective polymer portions polymerized and the MFR and the HMFR of the total polymer so that: (i) the relationship between the melt flow rate (MFR) under a load of 2.16 Kg at 230° C. of the resulting block copolymer and the melt flow rate (HMFR) of the block copolymer under a load of 10.20 Kg at 230° C. is log HMFR≧0.922 log MFR+1.44, (ii) said block copolymer has an ethylene content of 10 to 40% by weight.
Claim 2
Dependent Claim
306 words
In a process for producing a block copolymer by copolymerizing propylene with ethylene in the presence of a catalyst comprising a titanium trichloride composition and an organoaluminum compound and a molecular weight modifier, the improvement which comprises: (a) polymerizing propylene in two steps so that the resulting propylene homopolymer portion will consist of a lower molecular weight portion and a higher molecular weight portion, the intrinsic viscosity [η] H of said higher molecular portion and the intrinsic viscosity [η] L of said lower molecular weight portion having the relationship expressed by the following equation: 3.5≦[η].sub.H -[η].sub.L ≦7.0 said propylene homopolymerization is carried out so that the proportions of said lower molecular weight portion and said higher molecular weight portion are 40 to 60% and 60 to 40% by weight, respectively, (b) in a subsequent stage copolymerizing ethylene with propylene, in the presence of said propylene homopolymer portion, into a block copolymer consisting of said propylene homopolymer portion and an ethylene-propylene copolymer portion, the ethylene being polymerized with propylene so that the molecular weight of said ethylene-propylene copolymer portion will have a value between the molecular weights of said lower molecular weight portion and said higher molecular portion in said propylene homopolymer portion, and so that ethylene-propylene copolymer portion will have an ethylene content of 60-95% by weight based on said copolymer portion, and (c) controlling the amounts of the respective polymer portions polymerized and the MFR and the HMFR of the total polymer so that: (i) the relationship between the melt flow rate (MFR) under a load of 2.16 Kg at 230° C. of the resulting block copolymer and the melt flow rate (HMFR) of the block copolymer under a load of 10.20 Kg at 230° C. is log HMFR≧0.922 log MFR+1.44, (ii) said block copolymer has an ethylene content of 10 to 40% by weight.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the ethylene content in (b) is 70-90%.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the ethylene content in (ii) is 15-30%.
Claim 5
Dependent Claim
16 words
A process according to claim 1 wherein the MFR value of the final product is 0.1-20.
References Cited (Backward Citations)
DE2646189A1
Cited
US4291138A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |