Patent US4467065A successfully refreshed from Google Patents.
US4467065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semi-crystalline polymers stabilized for irradiation sterilization
Assignee: Becton Dickinson and Co
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Filing: 1981-01-08
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Granted: 1984-08-21
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Expires: 2001-01-08
Abstract
Abstract Semi-crystalline polymer having a narrow molecular weight distribution and having incorporated therein a non-crystalline mobilizing additive which increases the free volume of the polymer, with such a combination preventing embrittlement of the polymer during and subsequent to irradiation sterilization.
Inventors
- 👤 Joel Williams
- 👤 Terry Dunn
- 👤 Vivian Stannett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
A; A61; A61L; A61L2/00; A61L2/02; A61L2/08; B; B29; B29C; B29C71/00; B29C71/04; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0844; B29C35/0866; B29C2035/0872; B29K; B29K2023/00; B29K2023/10; B29K2023/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
80 words
A composition having improved irradiation sterilization stability when subject to irradiation, comprising: A semi-crystalline polyolefin having a crystalline content of from 20-90%, and a narrow molecular weight distribution wherein the ratio of the weight average molecular weight to the number average molecular weight is no greater than 9.0 said polyolefin having incorporated therein a mobilizing amount of a non-crystalline liquid mobilizing additive which increases the free volume of the polymer, said composition resisting embrittlement during and subsequent to irradiation sterilization.
Claim 2
Dependent Claim
80 words
A composition having improved irradiation sterilization stability when subject to irradiation, comprising: A semi-crystalline polyolefin having a crystalline content of from 20-90%, and a narrow molecular weight distribution wherein the ratio of the weight average molecular weight to the number average molecular weight is no greater than 9.0 said polyolefin having incorporated therein a mobilizing amount of a non-crystalline liquid mobilizing additive which increases the free volume of the polymer, said composition resisting embrittlement during and subsequent to irradiation sterilization.
Claim 3
Dependent Claim
14 words
The composition of claim 1 wherein the said ratio is no greater than 8.0.
Claim 4
Dependent Claim
13 words
The composition of claim 1 wherein the ratio is no greater than 6.0.
Claim 5
Dependent Claim
27 words
The composition of claim 3 wherein the mobilizing additive is miscible with the polyolefin and has a molecular weight of from 100 to 10,000 grams per mole.
Claim 6
Dependent Claim
20 words
The composition of claim 4 wherein the mobilizing additive has a density of from 0.6 to 1.9 grams/cm 3 .
Claim 7
Dependent Claim
12 words
The composition of claim 5 wherein the mobilizer is a hydrocarbon oil.
Claim 8
Dependent Claim
13 words
The composition of claim 5 wherein the mobilizing additive is a phthalic ester.
Claim 9
Dependent Claim
10 words
The composition of claim 6 wherein the polyolefin is polypropylene.
Claim 10
Dependent Claim
10 words
The composition of claim 1 wherein the polyolefin is polypropylene.
Claim 11
Dependent Claim
13 words
The composition of claim 9 wherein the ratio is from 2.0 to 4.0.
Claim 12
Dependent Claim
13 words
The composition of claim 10 wherein the mobilizing additive is a hydrocarbon oil.
References Cited (Backward Citations)
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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) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |