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US4521487A Expired / Lapsed US ⏱️ 0.0 years remaining

Particulate polyolefin expansion molding material

Assignee: Sumitomo Chemical Co Ltd
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Filing: 1984-09-21
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Granted: 1985-06-04
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Expires: 2004-09-21
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Abstract

Abstract A particulate polyolefin expansion molding material is disclosed. The material is comprised of a particulate polyolefin having a bulk density of 0.45 g/cc or more and a mean particle size of 150 to 2,000μ, having provided on the surface thereof at least one layer comprising an expanding agent, a binder and a filler. The material can be used in producing expansion molded articles without first forming the material into pellets as is conventionally done.

Inventors

  • 👤 Tatsuyuki Mitsuno
  • 👤 Masashi Yamamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 07:29
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J2323/00; C08J2323/02; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 64 words
A particulate polyolefin expansion molding material comprising a particulate polyolefin having a bulk density of 0.45 g/cc or more and a mean particle size of 150 to 2,000μ, said particles having coated on the surface thereof at least one layer comprising a solid decomposable expanding agent, a binder selected from the group consisting of olefinic polymers, petroleum resins and polyalkylene glycols and a filler.
Claim 2
Dependent Claim 64 words
A particulate polyolefin expansion molding material comprising a particulate polyolefin having a bulk density of 0.45 g/cc or more and a mean particle size of 150 to 2,000μ, said particles having coated on the surface thereof at least one layer comprising a solid decomposable expanding agent, a binder selected from the group consisting of olefinic polymers, petroleum resins and polyalkylene glycols and a filler.
Claim 3
Dependent Claim 36 words
A particulate polyolefin expansion molding material as claimed in claim 1, wherein said binder is in the molten state at a temperature lower than the melting point of said particulate polyolefin by at least 3° C.
Claim 4
Dependent Claim 22 words
A particulate polyolefin expansion molding material as claimed in claim 1, wherein said particulate polyolefin is a crystalline propylene homopolymer or copolymer.
Claim 5
Dependent Claim 36 words
A particulate polyolefin expansion molding material as claimed in claim 1, wherein said binder is in the molten state at a temperature lower than the decomposition temperature of said expanding agent by at least 5° C.
Claim 6
Dependent Claim 34 words
A particulate polyolefin expansion molding material as claimed in claim 1, wherein the amount of said expanding agent is 0.1 to 20 parts by weight per 100 parts by weight of said particulate polyolefin.
Claim 7
Dependent Claim 33 words
A particulate polyolefin expansion molding material as claimed in claim 1, wherein the amount of said filler is 0.1 to 150 parts by weight per 100 parts by weight of said particulate polyolefin.

References Cited (Backward Citations)

US4110273A Cited
US4331776A Cited
US4433029A Cited
US4463032A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-06-03 1988-12-03 1989-06-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-06-03 1992-12-03 1993-06-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-06-03 1996-12-03 1997-06-04 $7700.00 Window Closed / Lapsed

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