US4367185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing crosslinked polypropylene foam
Assignee: Furukawa Electric Co Ltd
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Filing: 1980-02-25
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Granted: 1983-01-04
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Expires: 2000-02-25
Abstract
Abstract In producing a crosslinked polypropylene foam, 0.5 to 4 parts by weight of a compound selected from triacrylate and trimethacrylate of aliphatic polyhydric alcohol and a blowing agent are mixed with 100 parts by weight of propylene homopolymer or copolymer. Then, the mixture is shaped under heat, followed by irradiation with an ionizing radiation such that the dose of the radiation absorbed by the shaped mass ranges between 0.1 and 10 Mrad. Finally, the irradiated mass is heated for foaming.
Inventors
- 👤 Akio Nojiri
- 👤 Takashi Sawasaki
- 👤 Toshio Koreeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:28
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0014; C08J9/0028; B; B29; B29C; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505; B29C44/56; C08J9/0023; B29K; B29K2023/00; B29K2023/10; B29K2023/12; B29K2105/00; B29K2105/24; C08J2323/00; C08J2323/02; C08J2323/10; Y; Y10; Y10S; Y10S264/00; Y10S264/16; Y10S264/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
104 words
A method of producing a crosslinked polypropylene foam shaped body, comprising the steps of: mixing 0.5 to 4 parts by weight of a compound selected from the group consisting of trimethylol propane triacrylate and trimethylol propane trimethacrylate, 0.1 to 5 parts by weight of a phenolic compound having at least 3 hydroxyl groups in the molecule and a blowing agent, with 100 parts by weight of propylene homopolymer or copolymer, shaping the mixture under heat, irradiating the shaped mass with an ionizing radiation such that the absorbed dose ranges between 0.1 and 5 Mrad, and heating the irradiated mass to foam the shaped body.
Claim 2
Independent Claim
104 words
A method of producing a crosslinked polypropylene foam shaped body, comprising the steps of: mixing 0.5 to 4 parts by weight of a compound selected from the group consisting of trimethylol propane triacrylate and trimethylol propane trimethacrylate, 0.1 to 5 parts by weight of a phenolic compound having at least 3 hydroxyl groups in the molecule and a blowing agent, with 100 parts by weight of propylene homopolymer or copolymer, shaping the mixture under heat, irradiating the shaped mass with an ionizing radiation such that the absorbed dose ranges between 0.1 and 5 Mrad, and heating the irradiated mass to foam the shaped body.
Claim 3
Independent Claim
107 words
A method of producing a crosslinking polypropylene foam, comprising the steps of: mixing 0.5 to 4 parts by weight of a compound selected from the group consisting of trimethylol propane triacrylate and trimethylol propane trimethacrylate, 0.1 to 5 parts by weight of a phenolic compound having at least 3 hydroxyl groups in the molecule with 100 parts by weight of propylene homopolymer or copolymer, shaping the mixture under heat, irradiating the shaped mass with an ionizing radiation such that the absorbed dose ranges between 0.1 and 5 Mrad, impregnating the irradiated mass with a volatile blowing agent, and heating the impregnated mass to foam the shaped body.
Claim 4
Independent Claim
107 words
A method of producing a crosslinking polypropylene foam, comprising the steps of: mixing 0.5 to 4 parts by weight of a compound selected from the group consisting of trimethylol propane triacrylate and trimethylol propane trimethacrylate, 0.1 to 5 parts by weight of a phenolic compound having at least 3 hydroxyl groups in the molecule with 100 parts by weight of propylene homopolymer or copolymer, shaping the mixture under heat, irradiating the shaped mass with an ionizing radiation such that the absorbed dose ranges between 0.1 and 5 Mrad, impregnating the irradiated mass with a volatile blowing agent, and heating the impregnated mass to foam the shaped body.
Claim 5
Dependent Claim
26 words
The method according to claim 1, wherein it takes at least 5 minutes for the blowing agent to begin to generate decomposed gas at 185° C.
Claim 6
Dependent Claim
26 words
The method according to claim 1, wherein it takes at least 10 minutes for the blowing agent to begin to generate decomposed gas at 185° C.
Claim 7
Dependent Claim
13 words
The method according to claim 1, wherein said compound is trimethylol propane triacrylate.
Claim 8
Dependent Claim
13 words
The method according to claim 1, wherein said compound is trimethylol propane trimethacrylate.
Claim 9
Dependent Claim
22 words
The method according to claim 1, wherein the amount of said triacrylate or trimethacrylate ranges between 1.0 and 2.5 parts by weight.
Claim 10
Dependent Claim
23 words
The method according to claim 1, or 2 or 7 wherein the absorbed dose of ionizing radiation ranges between 0.5 and 5 Mrad.
Claim 11
Dependent Claim
23 words
The method according to claim 1, or 2 or 7 wherein the absorbed dose of ionizing radiation ranges between 1 and 3 Mrad.
Claim 12
Dependent Claim
20 words
The method according to claim 1, wherein the irradiated mass is placed on a wire net and heated for foaming.
Claim 13
Independent Claim
42 words
The method according to any one of claims 1, 2, 4 or 7, wherein said phenolic compound having at least 3 hydroxyl groups in the molecule is selected from the group consisting of 1,1,3-tris-(5-t-butyl-4-hydroxy-2-methylphenyl) butane; octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)-propionate; tris-(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate; and 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene.
Claim 14
Dependent Claim
35 words
The method according to claim 9, wherein said phenolic compound having at least 3 hydroxyl groups in the molecule is selected from the group consisting of 1,1,3-tris-(5-t-butyl-4-hydroxy-2-methylphenyl) butane; octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)-propionate; tris-(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate; and 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene.
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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) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |