US4525486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing modified polyolefin particles and foamed article made from the particles
Assignee: KITA KU OSAKA SHI JAPAN
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Filing: 1983-10-28
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Granted: 1985-06-25
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Expires: 2003-10-28
Abstract
Abstract A process for preparing modified polyolefin particles which comprises dispersing cross-linked polyolefin particles and a polymerizable vinyl monomer capable of dissolving or swelling the cross-linked polyolefin particles in an aqueous medium, impregnating the cross-linked polyolefin particles with the vinyl monomer and polymerizing the vinyl monomer. The obtained modified polyolefin particles can provide a foamed article including uniform and fine cells and having excellent toughness, accuracy of demension, cushioning property, heat resistance and smooth and soft surface.
Inventors
- 👤 Shigeru Kobayashi
- 👤 Munehiro Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:09
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/18; C08J2351/00; C08J2351/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
80 words
A process for preparing modified foamable polyolefin particles which comprises dispersing previously cross-linked polyolefin particles and a polymerizable vinyl monomer capable of dissolving or swelling the cross-linked polyolefin particles in an aqueous medium, the degree of crosslinking of the cross-linked polyolefin particles being from 10 to 80% by weight; impregnating the cross-linked polyolefin particles uniformly inside with the vinyl monomer; polymerizing the vinyl monomer within the impregnated polyolefin particles; and thereafter impregnating the resulting polyolefin particles with a foaming agent.
Claim 2
Dependent Claim
80 words
A process for preparing modified foamable polyolefin particles which comprises dispersing previously cross-linked polyolefin particles and a polymerizable vinyl monomer capable of dissolving or swelling the cross-linked polyolefin particles in an aqueous medium, the degree of crosslinking of the cross-linked polyolefin particles being from 10 to 80% by weight; impregnating the cross-linked polyolefin particles uniformly inside with the vinyl monomer; polymerizing the vinyl monomer within the impregnated polyolefin particles; and thereafter impregnating the resulting polyolefin particles with a foaming agent.
Claim 3
Dependent Claim
33 words
The process of claim 1, wherein the cross-linked polyolefin particles are impregnated with a polymerization initiator capable of initiating the polymerization of the vinyl monomer, before impregnating the particles with the vinyl monomer.
Claim 4
Dependent Claim
35 words
The process of claim 1, wherein the impregnation and the polymerization are carried out by heating the mixture to a temperature of not less than a softening point of the polyolefin which is not cross-linked.
Claim 5
Dependent Claim
39 words
The process of claim 3, wherein the impregnation and the polymerization are carried out by heating the mixture to a temperature of not less than a softening point of the polyolefin, which is not yet cross-linked, plus 5° C.
Claim 6
Dependent Claim
18 words
The process of claim 1, wherein the impregnation and the polymerization are carried out at the same time.
Claim 7
Dependent Claim
53 words
The process of claim 1, wherein the polyolefin is a homo- or co-polymer of monoolefinically unsaturated monomer selected from the group consisting of ethylene, propylene, butene-1, pentene-1, 3-methylbutene-1, 4-methylhexene-1 and 5-methylhexene-1, a copolymer selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer and ethylene-methyl methacrylate copolymer, or an admixture thereof.
Claim 8
Dependent Claim
14 words
The process of claim 1, wherein the polymerizable vinyl monomer is a styrene monomer.
Claim 9
Dependent Claim
59 words
The process of claim 1, wherein the cross-linked polyolefin is divided into a plurality of fine spaces by intermolecular cross-linkage, the vinyl monomer is introduced into said finely divided spaces during said impregnation and the monomer is then polymerized within said spaces whereby the resulting modified polyolefin particles have a plurality of fine vinyl polymer particles uniformly distributed therein.
Claim 10
Dependent Claim
69 words
A foamed article of a polyolefin which comprises a fundamental material of a previously cross-linked polyolefin made by impregnating the cross-linked polyolefin with a polymerizable vinyl monomer uniformly therein, the degree of crosslinking of the cross-linked polyolefin being from 10 to 80% by weight, and by polymerizing the monomer within said polyolefin, and which contains not less than 200 closed cells per 1 mm 2 of the foamed article.
Claim 11
Dependent Claim
69 words
A foamed article of a polyolefin which comprises a fundamental material of a previously cross-linked polyolefin made by impregnating the cross-linked polyolefin with a polymerizable vinyl monomer uniformly therein, the degree of crosslinking of the cross-linked polyolefin being from 10 to 80% by weight, and by polymerizing the monomer within said polyolefin, and which contains not less than 200 closed cells per 1 mm 2 of the foamed article.
Claim 12
Dependent Claim
46 words
The article of claim 9, wherein the number of the closed cells is the number represented by the equation: Number of closed cells≧200×(50d).sup.2/3 in which d is a density (g/cm 3 ) of the foamed article and is selected from a range of 0.02 to 0.08.
Claim 13
Dependent Claim
14 words
The article of claim 9, wherein the polymerizable vinyl monomer is a styrene monomer.
Claim 14
Dependent Claim
54 words
The article of claim 9, wherein the polyolefin is a homo- or co-polymer of monoolefinically unsaturated monomer selected from the group consisting of ethylene, propylene, butene-1, pentene-1, 3-methylbutene-1, 4-methylbutene-1, 4-methylhexene-1 and 5-methylhexene-1, a copolymer selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer and ethylene-methyl methacrylate copolymer, or an admixture thereof.
Claim 15
Dependent Claim
19 words
The article of claim 11, wherein the cross-linking degree of the cross-linked polyolefin is 15 to 80% by weight.
Claim 16
Dependent Claim
30 words
The article of claim 9, wherein the foamed article comprises 13 to 75% by weight of the styrene polymer portion and 87 to 25% by weight of the polyolefin portion.
Claim 17
Dependent Claim
26 words
The article of claim 9, wherein said fundamental material is foamed by introducing a foaming agent therein and then heating to cause the material to expand.
Claim 18
Dependent Claim
28 words
The article of claim 9, wherein said fundamental material comprises a plurality of modified polyolefin particles each containing a plurality of fine vinyl polymer particles uniformly distributed therein.
Claim 19
Dependent Claim
20 words
The article of claim 16, wherein the particle size of the cross-linked polyolefin particles is about 0.25 to 10 mm.
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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) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |