CA1094974A - Irradiation of polymers - Google Patents
Irradiation of polymersInfo
- Publication number
- CA1094974A CA1094974A CA290,514A CA290514A CA1094974A CA 1094974 A CA1094974 A CA 1094974A CA 290514 A CA290514 A CA 290514A CA 1094974 A CA1094974 A CA 1094974A
- Authority
- CA
- Canada
- Prior art keywords
- polymer
- article
- mobilizing
- crystalline
- additive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
- C08J7/12—Chemical modification
- C08J7/123—Treatment by wave energy or particle radiation
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
- A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
- A61L2/08—Radiation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
- B29C71/04—After-treatment of articles without altering their shape; Apparatus therefor by wave energy or particle radiation, e.g. for curing or vulcanising preformed articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/10—Polymers of propylene
- B29K2023/12—PP, i.e. polypropylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0037—Other properties
- B29K2995/0041—Crystalline
Abstract
Abstract of the Disclosure An article of a semi-crystalline polymer such as polypropylene, is sterilized by high energy radiation, with the polymer containing a non-crystalline mobilizing additive which increases the free volume of the polymer, to thereby prevent embrittlement of the polymer during and subsequent to the irradiation.
Description
10~11974 IRRADIAT ON OF POLYMERS
This invention relates to the IrradiatLon of polymeric materLals, and more particularly to irradiation sterLlization of polymeric materials .
Semi-crystalline polymeric materials, such as polypropylene, are often employed in articles where it is necessary to subject the article to irradiation sterilization. Such materials, however, degrade during or subsequent to such irradiation; i. e., during shelf storage time, and as a result of such degradation, the articles become embrLttled. To date, it has not been generally possible to produce an irradiation sterilized polypropylelle article whLch ls not severely limited in its applications as a result of such embrittlement.
In accordance with the present invention, there is provided a process and products thereof for sterilizing a sem-crystalline polymer by subjecting such polymer to a sterilizing amount of hlgh energy radiation, wLth such polymer having Lncorporated thereLn a mobLlLzing amount of a non-crystalline lLquid mobLlizing additive which increases the free volume of the polymer and retains the flexibility thereof.
More particularly, $he mobilizer is a low molecular weight non-crystalline substance, which is miscible with the polymeric material and is also compatible therewith; i, e, the mobilizer does not adversely affect the properties of the polymer. The mobilizer is a substance which increases the free volume of the polymer and, therefore, also lowers the density of the polymer. The mobilizer functions to mobilize the amorphous portion of the polymer, and as .. "' ' ~9~974 a result, increases the radical terrnLnatLon reactions whLch prevent or minLmLze degradatLon during and subsequent to the irradLatLon.
The mobLlizer can be any one of a wLde varLety of liquids whLch Lncrease the total free volume of the polymer. The term liquid as used herein includes highly ~iscous substances, commonly referred to as greases. In general, such mobLlLzers have a densLty of from 0. 6 to 1, 9 g/cm3, and preferably of from 0. 6 to 1,1 g/cm3, The mobLlizer has a low molecular weight, with the average molecular weight generally being in the order of from 100 to 10, 000 grams/mole, and preferably from 100 to 5, 000 gramslmole.
As representa1;ive examples ~f suitable mobilizers, there may be mentioned: hydrocarbon olls, halogenated hydrQcarbon oils, phthalic ester oils, vegetable oils, silicone oils, low molecular weight non-crystalline polymer greases, such as hydrocarbon polymer greases, low molecular weight polyester greases, polyarylether greases, etc.
It is to be understood that the above examples are only illustrative and the use of other mobili~ers should be apparent to those skilled in the art from the teachings herein, The preferred mobilizer is a liquid mobilizer which is not highly ~riscous, and in particular, a hydro-carbon oil or phthalic ester oil.
The polymers employed in the present in~rentLon are semi-crystalline polymers, with such polymers having a crystalline content in the order of from 20% to 90~, and preferably of from 40% to ~0%.
The polymer may be comprised of one, two or more monomers, and 25 the term polymer generically refers to both homopolymers and co-polymers comprised of two or more monomers. As representativeexamples of suitable polymers, there may be mentioned: polymers of propylene, ethylene, oxymethylene, butylene, etc. The preferred 10~3~974 polymer is polypropylene, The mobllizer is Incorporated Lnto the polymer Ln a mobLllzing amount, wlth such mobLlLzer generally beLng present Ln an amount of from 0. 01% to 50% and preferably of Irom 0, 1% to 20%, all by weLght The polymer may also include other additives which are con-ventionally used in the art, such as antioxidants, preservatives, fLllers, etc.
A.lthough it Ls not Lntended that the present LnventLon be lLmLted by any theoretLcal reasoning, it Ls believed that irradiatLon degrades a polymer, such as polypropylene, by both chain scission and oxLdatlo~, as represented by the followLng equatLons:
(1) R _~ R-
This invention relates to the IrradiatLon of polymeric materLals, and more particularly to irradiation sterLlization of polymeric materials .
Semi-crystalline polymeric materials, such as polypropylene, are often employed in articles where it is necessary to subject the article to irradiation sterilization. Such materials, however, degrade during or subsequent to such irradiation; i. e., during shelf storage time, and as a result of such degradation, the articles become embrLttled. To date, it has not been generally possible to produce an irradiation sterilized polypropylelle article whLch ls not severely limited in its applications as a result of such embrittlement.
In accordance with the present invention, there is provided a process and products thereof for sterilizing a sem-crystalline polymer by subjecting such polymer to a sterilizing amount of hlgh energy radiation, wLth such polymer having Lncorporated thereLn a mobLlLzing amount of a non-crystalline lLquid mobLlizing additive which increases the free volume of the polymer and retains the flexibility thereof.
More particularly, $he mobilizer is a low molecular weight non-crystalline substance, which is miscible with the polymeric material and is also compatible therewith; i, e, the mobilizer does not adversely affect the properties of the polymer. The mobilizer is a substance which increases the free volume of the polymer and, therefore, also lowers the density of the polymer. The mobilizer functions to mobilize the amorphous portion of the polymer, and as .. "' ' ~9~974 a result, increases the radical terrnLnatLon reactions whLch prevent or minLmLze degradatLon during and subsequent to the irradLatLon.
The mobLlizer can be any one of a wLde varLety of liquids whLch Lncrease the total free volume of the polymer. The term liquid as used herein includes highly ~iscous substances, commonly referred to as greases. In general, such mobLlLzers have a densLty of from 0. 6 to 1, 9 g/cm3, and preferably of from 0. 6 to 1,1 g/cm3, The mobLlizer has a low molecular weight, with the average molecular weight generally being in the order of from 100 to 10, 000 grams/mole, and preferably from 100 to 5, 000 gramslmole.
As representa1;ive examples ~f suitable mobilizers, there may be mentioned: hydrocarbon olls, halogenated hydrQcarbon oils, phthalic ester oils, vegetable oils, silicone oils, low molecular weight non-crystalline polymer greases, such as hydrocarbon polymer greases, low molecular weight polyester greases, polyarylether greases, etc.
It is to be understood that the above examples are only illustrative and the use of other mobili~ers should be apparent to those skilled in the art from the teachings herein, The preferred mobilizer is a liquid mobilizer which is not highly ~riscous, and in particular, a hydro-carbon oil or phthalic ester oil.
The polymers employed in the present in~rentLon are semi-crystalline polymers, with such polymers having a crystalline content in the order of from 20% to 90~, and preferably of from 40% to ~0%.
The polymer may be comprised of one, two or more monomers, and 25 the term polymer generically refers to both homopolymers and co-polymers comprised of two or more monomers. As representativeexamples of suitable polymers, there may be mentioned: polymers of propylene, ethylene, oxymethylene, butylene, etc. The preferred 10~3~974 polymer is polypropylene, The mobllizer is Incorporated Lnto the polymer Ln a mobLllzing amount, wlth such mobLlLzer generally beLng present Ln an amount of from 0. 01% to 50% and preferably of Irom 0, 1% to 20%, all by weLght The polymer may also include other additives which are con-ventionally used in the art, such as antioxidants, preservatives, fLllers, etc.
A.lthough it Ls not Lntended that the present LnventLon be lLmLted by any theoretLcal reasoning, it Ls believed that irradiatLon degrades a polymer, such as polypropylene, by both chain scission and oxLdatlo~, as represented by the followLng equatLons:
(1) R _~ R-
(2) R- + O~RO2 -~3) R02 ' + RH~ROOH + R ' (4~ R02- + R-7~ROOR
(5) R- + R~ R-R
where R represents the long polymeric chaLn composing the polymer.
The abilLty of steps (2) and (3) to repeat themselves many times before terminatLon by eLther steps (4) or (5) results in an auto oxidative reactLon, Also, the stability of the radicals formed during irradiatlon allow this reaction to continue for long periods of time even after radiation has ceased. This post-degradation is very severe since a product can embrittle on the shelf although it was acceptable immedi-ately after LrradLation. In accordance with the present invention, it is believed that the presence of the mobilizlng addLtLve increases the radLcal termLnation reactions shown in steps ~4) and (5), Con-sequently, the oxidative steps (2) and (3) are minLmLzed during ~09 1974 irradLatLon, Equally Lmportant, however, the Lncreased termLnatlon rates brought about by the mobllizlng additive prevent and/or mLnimize the severe post-oxldatlve reaction. Therefore, the product does not embrittle during normal shelf time of several years.
The polymer, preferably polypropylene, Including the liquid mobilizer can be employed to produce an article which is to be sterilized by procedures known in the art. As representatlve examples of such articles, there may be mentloned: syrlnges, tube assemblles, tlssue culture flasks, needles, package film, etc.
The polymer having the mobilizer incorporated thereln, either as the polymeric material per se, or as an article, e, g" a syringe or package film, can be sterlllzed by subjectlng the polymer to a sterllizing amount of hlgh energy radlation. The hlgh energy radlation can be provided by any one of a variety of sources, including cobalt 60, 1& high energy electrons and X-rays. In general, the st~rillzing radlatlon doses are In the order of from 0. 5 to 6 meg~ads, with the typical dose belng 2. S megarads.
It has been found that by effecting the radiation sterilization of a '1,~
semi-crystalline polymer having incorporated therein a mobilizer, the sterilized or irradiated polymer is not embrittled, and moreover, does not become embrittled subsequent to the irradiation (no embrittlement with age); i.e., the polymer retains its flexibility. Thusg for example, prior to irradiation, such polymers have a bending angle of at least 90, and in accordance with the present invention, the irradiated polymer subsequent to irradiation and even after storage for a long period of time has a bending angle of at least 90.
1:.
r EXAMPLE I
Polypropylene contalnlng 4% of an allphatLc hydrocarbon oll havLng an average molecular welght of 1200 g/molecule ~moblllzlng addltlve) was Irradlated to 2, 5 megarads in alr. ~ollowlng LrradLatLon, the sample could be bent through an angle of 90, Even after 7 months of aging at ambient conditions, the sample could be bent through an angle of 90D. A correspondlng control polypropylene sample con-talning no mobllizLng addltlve wa~ severely embrlttled aft~r 2. 5 megarads, ~ fact, this sample only bent 45 before snapplng. When this sample was aged for 6 months, Lt was further embrlttled and "snapped" at only a ~0 bendLng ,angle, EXAMPL.~ II~
Polypropylene containing 2% dLoctyl phthalate wa~ irradlated (2. 5 megarads) In alr. Followlng lrradlatlon the sample was flexLble :
and coud bend through an angle of gO. The irradlated control sample contain~ng no mobilizing addltive would only bend through an angle of 20 bef~re snapping.
EXAMPLE III
Polypropylene contalning 3. 6% of a hydrocarbon oil as in Example I wa~ irradiat~d to 2~ 5 megarads Ln aLr. Followlng irradia-tion the sample was stlll flexible and would easlly bend th~ough an angle of 90 wlthout breaklng. A corresporldlng control sample contalnLng no mobillzlng addltLve was ~eYerely embrlttled after 2 5 megarads.
In fact, the control sample qnly bent 45 before snapplng. When this sample was aged 6 months~ It was further embrlttled and "snapped "
at only a 20 bending angle.
7~
EXAMPLE IV
The polypropylene sample as described in Example III except containing 2. Ds~o of a hydrocarbon oll. A.s in Example I, the sample was still flexLble after ~. 5 megarads and would bend through an angle of 90 without breakage.
EXAMPLE V
The polypropylene sample as described in Example III except containing 1 . 2 % of a hydrocarbon o il, As in Example I, the sarnple was still flexible after 2, 5 megarads and would bend through an angle of 90 without breakage, The present invention is particularly advantageous in that semi-crystalline polymer articles can be irradiation sterilized without detrimentally affecting the flexibility of such articles even after the articles have been stored over a period of time, ,~
(5) R- + R~ R-R
where R represents the long polymeric chaLn composing the polymer.
The abilLty of steps (2) and (3) to repeat themselves many times before terminatLon by eLther steps (4) or (5) results in an auto oxidative reactLon, Also, the stability of the radicals formed during irradiatlon allow this reaction to continue for long periods of time even after radiation has ceased. This post-degradation is very severe since a product can embrittle on the shelf although it was acceptable immedi-ately after LrradLation. In accordance with the present invention, it is believed that the presence of the mobilizlng addLtLve increases the radLcal termLnation reactions shown in steps ~4) and (5), Con-sequently, the oxidative steps (2) and (3) are minLmLzed during ~09 1974 irradLatLon, Equally Lmportant, however, the Lncreased termLnatlon rates brought about by the mobllizlng additive prevent and/or mLnimize the severe post-oxldatlve reaction. Therefore, the product does not embrittle during normal shelf time of several years.
The polymer, preferably polypropylene, Including the liquid mobilizer can be employed to produce an article which is to be sterilized by procedures known in the art. As representatlve examples of such articles, there may be mentloned: syrlnges, tube assemblles, tlssue culture flasks, needles, package film, etc.
The polymer having the mobilizer incorporated thereln, either as the polymeric material per se, or as an article, e, g" a syringe or package film, can be sterlllzed by subjectlng the polymer to a sterllizing amount of hlgh energy radlation. The hlgh energy radlation can be provided by any one of a variety of sources, including cobalt 60, 1& high energy electrons and X-rays. In general, the st~rillzing radlatlon doses are In the order of from 0. 5 to 6 meg~ads, with the typical dose belng 2. S megarads.
It has been found that by effecting the radiation sterilization of a '1,~
semi-crystalline polymer having incorporated therein a mobilizer, the sterilized or irradiated polymer is not embrittled, and moreover, does not become embrittled subsequent to the irradiation (no embrittlement with age); i.e., the polymer retains its flexibility. Thusg for example, prior to irradiation, such polymers have a bending angle of at least 90, and in accordance with the present invention, the irradiated polymer subsequent to irradiation and even after storage for a long period of time has a bending angle of at least 90.
1:.
r EXAMPLE I
Polypropylene contalnlng 4% of an allphatLc hydrocarbon oll havLng an average molecular welght of 1200 g/molecule ~moblllzlng addltlve) was Irradlated to 2, 5 megarads in alr. ~ollowlng LrradLatLon, the sample could be bent through an angle of 90, Even after 7 months of aging at ambient conditions, the sample could be bent through an angle of 90D. A correspondlng control polypropylene sample con-talning no mobllizLng addltlve wa~ severely embrlttled aft~r 2. 5 megarads, ~ fact, this sample only bent 45 before snapplng. When this sample was aged for 6 months, Lt was further embrlttled and "snapped" at only a ~0 bendLng ,angle, EXAMPL.~ II~
Polypropylene containing 2% dLoctyl phthalate wa~ irradlated (2. 5 megarads) In alr. Followlng lrradlatlon the sample was flexLble :
and coud bend through an angle of gO. The irradlated control sample contain~ng no mobilizing addltive would only bend through an angle of 20 bef~re snapping.
EXAMPLE III
Polypropylene contalning 3. 6% of a hydrocarbon oil as in Example I wa~ irradiat~d to 2~ 5 megarads Ln aLr. Followlng irradia-tion the sample was stlll flexible and would easlly bend th~ough an angle of 90 wlthout breaklng. A corresporldlng control sample contalnLng no mobillzlng addltLve was ~eYerely embrlttled after 2 5 megarads.
In fact, the control sample qnly bent 45 before snapplng. When this sample was aged 6 months~ It was further embrlttled and "snapped "
at only a 20 bending angle.
7~
EXAMPLE IV
The polypropylene sample as described in Example III except containing 2. Ds~o of a hydrocarbon oll. A.s in Example I, the sample was still flexLble after ~. 5 megarads and would bend through an angle of 90 without breakage.
EXAMPLE V
The polypropylene sample as described in Example III except containing 1 . 2 % of a hydrocarbon o il, As in Example I, the sarnple was still flexible after 2, 5 megarads and would bend through an angle of 90 without breakage, The present invention is particularly advantageous in that semi-crystalline polymer articles can be irradiation sterilized without detrimentally affecting the flexibility of such articles even after the articles have been stored over a period of time, ,~
Claims (17)
1. A process for sterilizing a semi-crystalline polymer, comprising:
subjecting to a sterilizing amount of high energy radiation a semi-crystalline polymer having a crystalline content of from 20-90%
and having incorporated therein a mobilizing amount of a non-crystalline liquid mobilizing additive which increases the free volume of the polymer and retains the flexibility thereof to thereby produce a sterilized poly-mer which retains its flexibility.
subjecting to a sterilizing amount of high energy radiation a semi-crystalline polymer having a crystalline content of from 20-90%
and having incorporated therein a mobilizing amount of a non-crystalline liquid mobilizing additive which increases the free volume of the polymer and retains the flexibility thereof to thereby produce a sterilized poly-mer which retains its flexibility.
2. The process of Claim 1 wherein the polymer is polypropylene.
3. The process of Claim 2 wherein the mobilizing additive is at least one of hydrocarbon oils, halogenated hydrocarbon oils, phthalic esters, polymer greases, vegetable oils or silicone oils.
4. The process of Claim 1, 2 or 3 wherein said mobilizing additive has a density of from 0.6 to 1.9 g/cm3.
5. The process of Claim 1, 2 or 3 wherein the polymer is in the form of an article.
6. The process of Claim 1, 2 or 3 wherein the mobilizing additive is a phthalic ester.
7. The process of Claim 1, 2 or 3 wherein the mobilizing additive is a hydrocarbon oil.
8. The process of Claim 1, 2 or 3 wherein the mobilizing additive is present in an amount of from 0.1% to 20%, by weight.
9. A flexible sterilized article, comprising:
a semi-crystalline polymer having a crystalline content of from 20-90%, said polymer having been irradiated with a sterilizing amount of high energy radiation while having incorporated therein a mobilizing amount of a non-crystalline mobilizing additive which increases the free volume of the polymer and retains the flexibility thereof.
a semi-crystalline polymer having a crystalline content of from 20-90%, said polymer having been irradiated with a sterilizing amount of high energy radiation while having incorporated therein a mobilizing amount of a non-crystalline mobilizing additive which increases the free volume of the polymer and retains the flexibility thereof.
10. The article of Claim 9 wherein the polymer is poly-propylene.
11. The article of Claim 10 wherein the mobilizing additive is at least one of hydrocarbon oils, halogenated hydrocarbon oils, phthalic esters, polymer greases, vegetable oils or silicone oils,
12. The article of Claim 9, 10 or 11 wherein said mobilizing additive has a density of from 0.6 to 1.9 g/cm3.
13. The article of Claim 9, 10 or 11 wherein the mobilizing additive is a phthalic ester.
14. The article of Claim 9, 10 or 11 wherein the mobilizing additive is a hydrocarbon oil.
15. The article of Claim 9, 10 or 11 wherein the mobilizing additive is present in an amount of from 0.1% to 20%, by weight.
16. The article of Claim 9, 10 or 11 in the form of a syringe.
17. The article of Claim 9, 10 or 11 in the form of a package film.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US740,618 | 1976-11-10 | ||
| US05/740,618 US4110185A (en) | 1976-11-10 | 1976-11-10 | Irradiation sterilization of semi-crystalline polymers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094974A true CA1094974A (en) | 1981-02-03 |
Family
ID=24977329
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA290,514A Expired CA1094974A (en) | 1976-11-10 | 1977-11-09 | Irradiation of polymers |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4110185A (en) |
| BE (1) | BE860656A (en) |
| CA (1) | CA1094974A (en) |
| DE (1) | DE2749872A1 (en) |
| FR (1) | FR2370769A1 (en) |
| GB (1) | GB1588818A (en) |
| IE (1) | IE45980B1 (en) |
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|---|---|---|---|---|
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| US4274932A (en) * | 1979-09-10 | 1981-06-23 | Becton Dickinson And Company | Semi-crystalline polymers stabilized for irradiation sterilization |
| US4467065A (en) * | 1979-09-10 | 1984-08-21 | Becton Dickinson And Company | Semi-crystalline polymers stabilized for irradiation sterilization |
| EP0078603A1 (en) * | 1981-10-12 | 1983-05-11 | Imperial Chemical Industries Plc | Polyolefin compositions and articles sterilisable by irradiation |
| US4749734A (en) * | 1982-02-23 | 1988-06-07 | Becton, Dickinson And Company | Radiation stabilization of polymeric material |
| US4427631A (en) * | 1982-05-27 | 1984-01-24 | Euroceltique, S.A. | Povidone irradiation |
| US4710524A (en) * | 1983-10-26 | 1987-12-01 | Becton, Dickinson And Company | High energy radiation stabilization of semi-crystalline polymers |
| NZ208423A (en) | 1983-10-26 | 1987-05-29 | Becton Dickinson Co | Sterilised, radiation-stabilised semi-crystalline polymer articles |
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| US5209984A (en) * | 1989-06-26 | 1993-05-11 | Minnesota Mining And Manufacturing Company | Films of radiation resistant heat sealable polymer blends having a surface adhesion layer grafted thereto |
| US5258419A (en) * | 1989-06-26 | 1993-11-02 | Minnesota Mining And Manufacturing Company | Methods of preparing radiation resistant heat sealable polymer blends |
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| US5331019A (en) * | 1990-09-04 | 1994-07-19 | Becton, Dickinson And Company | Lubricious radiation stable polymeric composition and articles therefrom |
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| US5176872A (en) * | 1992-02-19 | 1993-01-05 | Rexene Products Company | Polypropylene resins for multiple cavity stretch blow molding |
| US5376716A (en) * | 1992-08-31 | 1994-12-27 | Rexene Products Company | Radiation resistant polypropylene resins |
| ZA938951B (en) * | 1992-12-21 | 1994-08-02 | Kimberly Clark Co | Packaging and methods for reducing odors and strength loss caused by the irradiation of polyolefin-based products |
| EP0735089B1 (en) * | 1995-03-31 | 2004-09-22 | Basell North America Inc. | Polyolefin compositions resistant to high energy radiation, and articles produced therefrom |
| CN1091453C (en) | 1995-08-29 | 2002-09-25 | 埃克森美孚化学专利公司 | Radiation tolerant polypropylene and its useful articles |
| IT1285393B1 (en) * | 1996-06-04 | 1998-06-03 | Hospal Dasco Spa | FORMULATION OF PLASTIFIED POLYVINYL CLORIDE FOR THE REALIZATION OF COMPONENTS IN BIOCOMPATIBLE MATERIAL, IN PARTICULAR OF LINES |
| US5804620A (en) * | 1996-06-18 | 1998-09-08 | Montell North America Inc. | Embrittlement-resistant polyolefin composition and flexible articles therefrom |
| US5929147A (en) * | 1996-06-18 | 1999-07-27 | Montell North America Inc. | Embrittlement-resistant polyolefin composition and flexible articles therefrom |
| US5994436A (en) * | 1997-12-18 | 1999-11-30 | Montell North America Inc. | Ductile gamma radiation resistant polyolefin composition and articles produced therefrom |
| US7662885B2 (en) * | 2002-08-12 | 2010-02-16 | Exxonmobil Chemical Patents Inc. | Method to make an article comprising polymer concentrate |
| US7531594B2 (en) | 2002-08-12 | 2009-05-12 | Exxonmobil Chemical Patents Inc. | Articles from plasticized polyolefin compositions |
| US7271209B2 (en) | 2002-08-12 | 2007-09-18 | Exxonmobil Chemical Patents Inc. | Fibers and nonwovens from plasticized polyolefin compositions |
| US7629416B2 (en) * | 2002-08-12 | 2009-12-08 | Exxonmobil Chemical Patents Inc. | Plasticized polyolefin compositions |
| US7998579B2 (en) | 2002-08-12 | 2011-08-16 | Exxonmobil Chemical Patents Inc. | Polypropylene based fibers and nonwovens |
| US8003725B2 (en) | 2002-08-12 | 2011-08-23 | Exxonmobil Chemical Patents Inc. | Plasticized hetero-phase polyolefin blends |
| CA2492839C (en) | 2002-08-12 | 2011-02-01 | Exxonmobil Chemical Patents Inc. | Plasticized polyolefin compositions |
| US7652092B2 (en) * | 2002-08-12 | 2010-01-26 | Exxonmobil Chemical Patents Inc. | Articles from plasticized thermoplastic polyolefin compositions |
| US7795366B2 (en) * | 2002-08-12 | 2010-09-14 | Exxonmobil Chemical Patents Inc. | Modified polyethylene compositions |
| US7652094B2 (en) * | 2002-08-12 | 2010-01-26 | Exxonmobil Chemical Patents Inc. | Plasticized polyolefin compositions |
| US7622523B2 (en) | 2002-08-12 | 2009-11-24 | Exxonmobil Chemical Patents Inc. | Plasticized polyolefin compositions |
| US20040071952A1 (en) * | 2002-10-01 | 2004-04-15 | Anderson David Wayne | Aramid paper laminate |
| US8192813B2 (en) | 2003-08-12 | 2012-06-05 | Exxonmobil Chemical Patents, Inc. | Crosslinked polyethylene articles and processes to produce same |
| US20050137368A1 (en) * | 2003-12-17 | 2005-06-23 | Weqing Weng | Radiation tolerant copolymers |
| WO2005080495A1 (en) * | 2004-02-12 | 2005-09-01 | Exxonmobil Chemical Patents Inc. | Plasticized polyolefin compositions |
| US8389615B2 (en) | 2004-12-17 | 2013-03-05 | Exxonmobil Chemical Patents Inc. | Elastomeric compositions comprising vinylaromatic block copolymer, polypropylene, plastomer, and low molecular weight polyolefin |
| ATE555166T1 (en) | 2005-07-15 | 2012-05-15 | Exxonmobil Chem Patents Inc | ELASTOMERIC COMPOSITIONS |
| US7576140B2 (en) * | 2005-10-18 | 2009-08-18 | Sabic Innovative Plastics Ip B.V. | Method of improving abrasion resistance of plastic article and article produced thereby |
| JP2013515871A (en) | 2009-12-23 | 2013-05-09 | インビスタ テクノロジーズ エス エイ アール エル | Elastic fiber containing anti-adhesive additive |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3362897A (en) * | 1962-11-21 | 1968-01-09 | Gen Electric | Stable irradiated polyethylene |
| US3537967A (en) * | 1966-07-29 | 1970-11-03 | Dart Ind Inc | Radiation sterilized,thiodipropionic acid ester stabilized,propylene polymers |
| US3579303A (en) * | 1968-03-06 | 1971-05-18 | Donald E Pickering | System for handling specimens and other substances in medicine and physical sciences |
| US3758273A (en) * | 1970-04-03 | 1973-09-11 | Gillette Co | Processes for sterilizing polypropylene objects |
| JPS4939637A (en) * | 1972-08-24 | 1974-04-13 | ||
| US3989611A (en) * | 1973-01-08 | 1976-11-02 | The Firestone Tire & Rubber Company | Radiation treatment of polymers containing isobutylene |
-
1976
- 1976-11-10 US US05/740,618 patent/US4110185A/en not_active Expired - Lifetime
-
1977
- 1977-11-08 FR FR7733634A patent/FR2370769A1/en active Granted
- 1977-11-08 DE DE19772749872 patent/DE2749872A1/en not_active Ceased
- 1977-11-09 BE BE182491A patent/BE860656A/en not_active IP Right Cessation
- 1977-11-09 IE IE2283/77A patent/IE45980B1/en not_active IP Right Cessation
- 1977-11-09 GB GB46617/77A patent/GB1588818A/en not_active Expired
- 1977-11-09 CA CA290,514A patent/CA1094974A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IE45980L (en) | 1978-05-10 |
| US4110185A (en) | 1978-08-29 |
| BE860656A (en) | 1978-03-01 |
| FR2370769B1 (en) | 1984-07-06 |
| GB1588818A (en) | 1981-04-29 |
| FR2370769A1 (en) | 1978-06-09 |
| IE45980B1 (en) | 1983-01-12 |
| DE2749872A1 (en) | 1978-05-18 |
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