US4440899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyolefin powder compositions, in particular polyethylene powder compositions, with improved adhesion, and objects made or to be made of such compositions
Assignee: Stamicarbon BV
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Filing: 1981-08-31
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Granted: 1984-04-03
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Expires: 2001-08-31
Abstract
Abstract A polyolefin composition having improved adhesion to foamable plastic substrates, comprising an intimate mixture of about 20% to about 99.5% by weight of a first stabilized polyolefin powder and from about 0.5% to about 80% by weight of a second at most slightly stabilized polyolefin powder, said second powder having a crystalline melting point which is at least 1° higher than that of said first powder and wherein said second powder has the ability to be oxidized under process conditions.
Inventors
- 👤 Erik R. Peerlkamp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:50
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08J; C08J9/00; C08J9/34; B; B29; B29C; B29C44/00; B29C44/02; B29C44/04; B29C44/0423; B29C44/043; B63; B63B; B63B32/00; B63B32/57; C09; C09D; C09D123/00; C09D123/02; C09D123/04; C09D123/06; C08J2375/00; C08J2375/04; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249987; Y10T428/249988; Y10T428/249989
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A polyolefin composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of about 20 percent to about 99.5 percent by weight of a first stabilized polyolefin powder, said first polyolefin powder containing at least about 0.025 percent by weight of a stabilizer, with about 0.5 percent to about 80 percent by weight of a second at most slightly stabilized polyolefin powder, said second powder having a crystalline melting point which is at least 1° C. higher than said first powder such that during rotational molding said composition forms a stabilized outer layer and a non-stabilized inner layer.
Claim 2
Dependent Claim
108 words
A polyolefin composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of about 20 percent to about 99.5 percent by weight of a first stabilized polyolefin powder, said first polyolefin powder containing at least about 0.025 percent by weight of a stabilizer, with about 0.5 percent to about 80 percent by weight of a second at most slightly stabilized polyolefin powder, said second powder having a crystalline melting point which is at least 1° C. higher than said first powder such that during rotational molding said composition forms a stabilized outer layer and a non-stabilized inner layer.
Claim 3
Dependent Claim
107 words
A polyethylene composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of about 20 percent to about 99.5 percent by weight of a first stabilized polyethylene powder, said first powder containing at least about 0.025 percent by weight of a stabilizer, with about 0.5 percent to about 80 percent by weight of a second at most slightly stabilized polyethylene powder, said second powder having a crystalline melting point which is at least 4° C. higher than said first powder such that during rotational molding said composition forms a stabilized outer layer and a non-stabilized inner layer.
Claim 4
Dependent Claim
107 words
A polyethylene composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of about 20 percent to about 99.5 percent by weight of a first stabilized polyethylene powder, said first powder containing at least about 0.025 percent by weight of a stabilizer, with about 0.5 percent to about 80 percent by weight of a second at most slightly stabilized polyethylene powder, said second powder having a crystalline melting point which is at least 4° C. higher than said first powder such that during rotational molding said composition forms a stabilized outer layer and a non-stabilized inner layer.
Claim 5
Dependent Claim
42 words
A composition according to claims 1 or 2, wherein said composition comprises about 70% to about 90% by weight of said first stabilized polyolefin powder and about 10% to about 30% by weight of said second at most slightly stabilized polyolefin powder.
Claim 6
Dependent Claim
21 words
A composition according to claim 1 or 2 wherein said second powder contains at most about 0.01% stabilizing agents by weight.
Claim 7
Dependent Claim
21 words
A composition according to claim 1 or 2 wherein said second powder contains at most about 0.005% stabilizing agents by weight.
Claim 8
Dependent Claim
119 words
A polyethylene composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of: (a) about 70 percent to about 90 percent by weight of a first stabilized polyethylene powder, said first powder containing at least about 0.025 percent by weight of stabilizers with (b) about 10 percent to about 30 percent by weight of a second at most slightly stabilized polyethylene powder, said second powder having a crystalline melting point which is at least 4° C. higher than said first powder and containing at most about 0.01 percent by weight stabilizers, during rotational molding said powders respectively forming a stabilized non-oxidized outer layer and a non-stabilized oxidized inner layer.
Claim 9
Dependent Claim
119 words
A polyethylene composition for rotational molding having improved adhesion to a substrate and easily releasable from mold walls, comprising an intimate mixture of: (a) about 70 percent to about 90 percent by weight of a first stabilized polyethylene powder, said first powder containing at least about 0.025 percent by weight of stabilizers with (b) about 10 percent to about 30 percent by weight of a second at most slightly stabilized polyethylene powder, said second powder having a crystalline melting point which is at least 4° C. higher than said first powder and containing at most about 0.01 percent by weight stabilizers, during rotational molding said powders respectively forming a stabilized non-oxidized outer layer and a non-stabilized oxidized inner layer.
Claim 10
Dependent Claim
18 words
A composition according to claim 1, 2 or 6 wherein said first powder is a homopolymer of ethylene.
Claim 11
Dependent Claim
25 words
A composition according to claim 1, 2 or 6, wherein said first powder is a copolymer of ethylene with a minor amount of another olefin.
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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) | 1987-04-03 | 1987-10-03 | 1988-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-03 | 1991-10-03 | 1992-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-03 | 1995-10-03 | 1996-04-03 | $7700.00 | Window Closed / Lapsed |