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US4950549A Expired / Lapsed US ⏱️ 0.0 years remaining

Polypropylene articles and method for preparing same

Assignee: 3M Co
•
Filing: 1989-03-20
•
Granted: 1990-08-21
•
Expires: 2009-03-20
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Abstract

Abstract Polypropylene articles are provided. The polypropylene articles comprise non-crystalline mesomorphous polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene. The irradiated polypropylene articles retain useful tensile properties after storage periods of as long as at least about four months. Further provided is a method for preparing irradiated polypropylene articles having olefinic unsaturation-containing monomers graft-polymerized thereon comprising the steps of melt extruding polypropylene; quenching the extruded polypropylene immediately after extrusion to provide non-crystalline mesomorphous polypropylene; coating the non-crystalline mesomorphous polypropylene with an ionizing radiation graft-polymerizable monomer; and irradiating the coated non-crystalline mesomorphous polypropylene with a dosage of ionizing radiation sufficient to degrade crystalline polypropylene and sufficient to effect graft-polymerization of the monomer onto the surface of the polypropylene.

Inventors

  • 👤 Richard J. Rolando
  • 👤 Dennis L. Krueger
  • 👤 Daniel E. Meyer
  • 👤 Thomas I. Insley

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 06:59
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; C08J7/16; C08J7/18; D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56; C08J2323/00; C08J2323/02; C08J2323/10; C08J2323/12; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 44 words
A polypropylene article comprising non-crystalline mesomorphous polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene, said non-crystalline mesomorphous polypropylene retaining useful tensile properties after storage periods of as long as at least about four months.
Claim 2
Dependent Claim 44 words
A polypropylene article comprising non-crystalline mesomorphous polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene, said non-crystalline mesomorphous polypropylene retaining useful tensile properties after storage periods of as long as at least about four months.
Claim 3
Dependent Claim 11 words
The article of claim 1 wherein said article is polypropylene film.
Claim 4
Dependent Claim 23 words
The article of claim 2 wherein said article retains an elongation at break of at least 200 percent after about four months storage.
Claim 5
Dependent Claim 14 words
The article of claim 1 wherein said article is a polypropylene blown microfiber web.
Claim 6
Dependent Claim 21 words
The article of claim 4 wherein said article retains a modulus of resilience of at least about 20 N-m/cm 3 .
Claim 7
Dependent Claim 19 words
The article of claim 1 wherein said monomer is graft-polymerized onto said non-crystalline mesomorphous polypropylene by electron beam radiation.
Claim 8
Dependent Claim 21 words
The article of claim 6 wherein said electron beam radiation is provided at a dosage of about 0.5 to 10 Mrads.
Claim 9
Dependent Claim 26 words
The article of claim 1 wherein said monomer is acrylic acid, methacrylic acid, N-vinyl-2-pyrrolidone, acrylamide, substituted acrylamide, vinyl pyridine, an acrylic ester, or a methacrylic ester.
Claim 10
Dependent Claim 51 words
A polypropylene article comprising non-crystalline mesomorphous polypropylene, said polypropylene being free of radiation stabilizing additives and having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene, said polypropylene retaining useful tensile properties after storage periods of as long as at least about four months.
Claim 11
Dependent Claim 51 words
A polypropylene article comprising non-crystalline mesomorphous polypropylene, said polypropylene being free of radiation stabilizing additives and having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene, said polypropylene retaining useful tensile properties after storage periods of as long as at least about four months.

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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) 1993-08-20 1994-02-19 1994-08-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-08-20 1998-02-19 1998-08-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-08-20 2002-02-19 2002-08-21 $7700.00 Window Closed / Lapsed

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