US4291138A
Expired / Lapsed
US
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Production of modified polypropylenes
Assignee: Mitsubishi Chemical Corp
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Filing: 1979-11-19
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Granted: 1981-09-22
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Expires: 1999-11-19
Abstract
Abstract A modified polypropylene having improved impact resistance is obtained by producing, in the presence of a stereoregular polymerization catalyst and in three steps, two types of polypropylene blocks formed stepwise at different temperatures and then poly(ethylene or ethylene/propylene) block, the polymerization temperatures employed and the quantities of polymers produced in each step being in specific ranges.
Inventors
- 👤 Hideo Sato
- 👤 Toshio Yagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:49
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/06; C08F297/08; C08F297/083; C08F297/086
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
180 words
A process for producing a modified polypropylene in the presence of a stereoregular polymerization catalyst which comprises, in combination: Step 1 wherein propylene is polymerized at a temperature of not higher than 60° C. to produce 0.5 to 30% by weight of a crystalline propylene polymer on the basis of the total polymerization product obtained in Steps 1 through 3; Step 2 wherein propylene is further polymerized at a temperature which is at least 10° C. higher than that of Step 1 to produce 60 to 95% by weight of a crystalline propylene polymer on the basis of the total polymerization product in Steps 1 through 3, the quantity of the crystalline propylene polymer being the total quantity through Steps 1 and 2; and Step 3 wherein a member selected from the group consisting of ethylene and an ethylene-propylene mixture is polymerized to produce 5 to 40% by weight of an ethylene polymer on the basis of the total polymerization product in Steps 1 through 3, the ethylene content in the resulting ethylene polymer being 100 to 20% by weight.
Claim 2
Dependent Claim
180 words
A process for producing a modified polypropylene in the presence of a stereoregular polymerization catalyst which comprises, in combination: Step 1 wherein propylene is polymerized at a temperature of not higher than 60° C. to produce 0.5 to 30% by weight of a crystalline propylene polymer on the basis of the total polymerization product obtained in Steps 1 through 3; Step 2 wherein propylene is further polymerized at a temperature which is at least 10° C. higher than that of Step 1 to produce 60 to 95% by weight of a crystalline propylene polymer on the basis of the total polymerization product in Steps 1 through 3, the quantity of the crystalline propylene polymer being the total quantity through Steps 1 and 2; and Step 3 wherein a member selected from the group consisting of ethylene and an ethylene-propylene mixture is polymerized to produce 5 to 40% by weight of an ethylene polymer on the basis of the total polymerization product in Steps 1 through 3, the ethylene content in the resulting ethylene polymer being 100 to 20% by weight.
Claim 3
Dependent Claim
29 words
The process as set forth in claim 1, in which the stereoregular polymerization catalyst is a complex catalyst comprising a transition metal halide component and an organo-aluminum compound component.
Claim 4
Dependent Claim
44 words
The process as set forth in claim 2, in which the molar ratio of the components contained in the catalyst is in the range of 1 mol of the transition metal compound to from about 1 to about 300 mols of the organo-aluminum compound.
Claim 5
Dependent Claim
43 words
The process as set forth in claim 1, in which the polymerization of propylene in Step 1 is carried out at a temperature of about 50° C. to room temperature under a pressure of about 1 to about 50 Kg/cm 2 (absolute pressure).
Claim 6
Dependent Claim
45 words
The process as set forth in claim 1, in which the polymerization of propylene in Step 1 is continued until the polymerized quantity reaches about 1 to about 10% by weight on the basis of the total polymerization product obtained in Steps 1 through 3.
Claim 7
Dependent Claim
33 words
The process as set forth in claim 1, in which the polymerization of propylene in Step 2 is carried out under a pressure of about 1 to about 50 Kg/cm 2 (absolute pressure).
Claim 8
Dependent Claim
42 words
The process as set forth in claim 1, in which the polymerization in Step 3 is carried out at a temperature which is not higher than about 100° C. and under a pressure of about 1 to 50 Kg/cm 2 (absolute pressure).
Claim 9
Dependent Claim
38 words
The process as set forth in claim 1, in which the polymerized quantity in Step 3 is about 7 to about 25% by weight on the basis of the total polymerization product obtained in Steps 1 through 3.
Claim 10
Dependent Claim
29 words
The process as set forth in claim 1, in which the ethylene content in the ethylene polymer formed in Step 3 is about 90 to about 30% by weight.
Claim 11
Dependent Claim
32 words
The process as set forth in claim 9, in which the balance relative to the ethylene content is propylene or a mixture of propylene and a small amount of a copolymerizable monomer.
Claim 12
Dependent Claim
94 words
The process of claim 1 in which Step 1 is carried out at a temperature of about 50° C. to room temperature under a pressure of about 1 to about 50 Kg/cm 2 absolute, Step 2 is carried out at a temperature from above about 65° C. to about 90° C. under a pressure of about 1 to about 50 Kg./cm 2 absolute and Step 3 is carried out at a temperature in the range of about 20° C. to 80° C. under a pressure of about 1 to about 50 Kg/cm 2 absolute.
References Cited (Backward Citations)
US4066718A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |