US3714083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing foamed article from polypropylene
Assignee: Mitsubishi Chemical Corp
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Filing: 1969-01-13
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Granted: 1973-01-30
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Expires: 1989-01-13
Abstract
Abstract A method of producing a foamed article having a uniform cellular structure using a modified polypropylene produced by irradiating polypropylene with an ionizing radiation of from 0.1 to 5.0 megarad and graft-copolymerizing the irradiated polypropylene with from 0.5 - 6 percent by weight divinyl benzene or with from 0.5 - 6 percent by weight of divinyl benzene and not more than 10 percent by weight of an acrylic acid ester.
Inventors
- 👤 Y Nakayama
- 👤 T Fukada
- 👤 M Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:44
CPC Classifications
C; C08; C08F; C08F255/00; C08F255/02; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08J9/102; C08J9/103; C08J2351/00; C08J2351/06; Y; Y10; Y10S; Y10S521/00; Y10S521/915
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad, then graft-copolymerizing the resulting irradiated polypropylene with from 0.5 to 6% by weight divinyl benzene, forming a mixture of the resulting modified graft-co-polymerized polypropylene with a foaming agent having a decomposition point higher than the melting point of said modified graft-copolymerized polypropylene and then heating said mixture in a mold.
Claim 2
Dependent Claim
86 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad, then graft-copolymerizing the resulting irradiated polypropylene with from 0.5 to 6% by weight divinyl benzene, forming a mixture of the resulting modified graft-co-polymerized polypropylene with a foaming agent having a decomposition point higher than the melting point of said modified graft-copolymerized polypropylene and then heating said mixture in a mold.
Claim 3
Dependent Claim
11 words
The foamed product produced by the process according to claim 1.
Claim 4
Dependent Claim
25 words
The process according to claim 1, wherein said foaming agent is a member selected from the group consisting of azobis carbonamide and N, N''-dinitrosopentamethylene tetramine.
Claim 5
Dependent Claim
99 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad, then graft-copolymerizing the resulting irradiated polypropylene with from 0.5 to 6 percent by weight divinyl benzene and from 0.5 to 4 percent by weight of an acrylic acid ester, forming a mixture of the modified graft-copolymerized polypropylene with a foaming agent having a decomposition point higher than the melting point of said modified graft-copolymerized polypropylene and then heating said mixture in a mold.
Claim 6
Dependent Claim
99 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad, then graft-copolymerizing the resulting irradiated polypropylene with from 0.5 to 6 percent by weight divinyl benzene and from 0.5 to 4 percent by weight of an acrylic acid ester, forming a mixture of the modified graft-copolymerized polypropylene with a foaming agent having a decomposition point higher than the melting point of said modified graft-copolymerized polypropylene and then heating said mixture in a mold.
Claim 7
Dependent Claim
11 words
The foamed product produced by the process according to claim 4.
Claim 8
Dependent Claim
25 words
The process according to claim 4, wherein said foaming agent is a member selected from the group consisting of azobis carbonamide and N, N''-dinitrosopenatamethylene tetramine.
Claim 9
Dependent Claim
127 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad at a temperature of from -20* to -40*C, then graft-copolymerizing the resulting irradiated polypropylene with from 1 to 3 percent by weight divinyl benzene and from 0.5 to 4 percent by weight of an acrylic acid ester at a temperature of from 30* to 40*C in a solution of said divinyl benzene and said acrylic acid ester, forming a mixture of the resulting modified graft-copolymerized polypropylene with a foaming agent selected from the group consisting of azobis carbonamide and N, N''-dinitrosopentamethylene tetramine and then heating said mixture in a mold. 7.
Claim 10
Dependent Claim
127 words
A process of producing a foamed product consisting essentially of irradiating polypropylene having a specific gravity of about 0.91 and a melt index of about 3.6 with an ionizing radiation of from 0.1 to 5.0 megarad at a temperature of from -20* to -40*C, then graft-copolymerizing the resulting irradiated polypropylene with from 1 to 3 percent by weight divinyl benzene and from 0.5 to 4 percent by weight of an acrylic acid ester at a temperature of from 30* to 40*C in a solution of said divinyl benzene and said acrylic acid ester, forming a mixture of the resulting modified graft-copolymerized polypropylene with a foaming agent selected from the group consisting of azobis carbonamide and N, N''-dinitrosopentamethylene tetramine and then heating said mixture in a mold. 7.
References Cited (Backward Citations)
US3294869A
Cited
US3413244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |