Radiation resistant polypropylene useful in medical applications
Blends useful as an additive in polyolefin polymers for minimizing the effects of radiation on the physical properties of polymers, which comprises a hindered amine light stabilizer and at least one material selected from the group consisting of: i) amine oxides and ii) hydroxylamines. Various articles of manufacture may be produced using a composition or blend according to the invention, and the physical properties of such articles are less effected by electromagnetic radiation than like-kind compositions of the prior art.
1 ) A blend useful as an additive in polyolefin polymers for minimizing the effects of radiation on the physical properties of said polymers, which comprises a hindered amine light stabilizer and at least one material selected from the group consisting of: i) amine oxides exemplified by the formula:
in which R 1 and R 2 are each independently selected from C 10 to C 24 alkyl, aryl, or alkylaryl groups, whether straight-chain, branched, cyclic, saturated, or unsaturated; and ii) hydroxylamines exemplified by the formula:
in which R 1 and R 2 are each independently selected from C 10 to C 24 alkyl, aryl, or alkylaryl groups, whether straight-chain, branched, cyclic, saturated, or unsaturated.
2 ) A polymerized olefin polymer composition comprising:
a polymer, and
a blend that comprises a hindered amine light stabilizer and at least one material selected from the group consisting of: i) amine oxides exemplified by the formula:
in which R 1 and R 2 are each independently selected from C 10 to C 24 alkyl, aryl, or alkylaryl groups, whether straight-chain, branched, cyclic, saturated, or unsaturated; and ii) hydroxylamines exemplified by the formula:
in which R 1 and R 2 are each independently selected from C 10 to C 24 alkyl, aryl, or alkylaryl groups, whether straight-chain, branched, cyclic, saturated, or unsaturated.
3 ) An olefin polymer according to claim 2 wherein said polymer is selected from the group consisting of: propylene homopolymers, propylene co-polymers, ethylene homopolymers, and ethylene co-polymers, wherein when said olefin polymer comprises a co-polymer of either propylene or ethylene, said co-polymer is a co-polymer which was formed in the presence of at least one monomer comprising a C 2 to C 8 mono-olefin.
4 ) A composition according to claim 2 which further comprises a sorbitol-based clarifier present in any amount between 500 ppm and 5000 ppm by weight based on the total weight of said polymer.
5 ) A composition according to claim 2 which further comprises an inorganic clarifier present in any amount between 500 ppm and 5000 ppm by weight based on the total weight of said polymer.
6 ) A composition according to claim 2 which further comprises an inorganic nucleator present in any amount between 250 ppm and 2500 ppm by weight based on the total weight of said polymer.
7 ) A composition according to claim 2 wherein an amine oxide is present, and wherein the ratio of amine oxide to hindered amine light stabilizer is any ratio in the range of between about 1:0.2 to 1:5.
8 ) A composition according to claim 2 wherein a hydroxyl amine is present, and wherein the ratio of hydroxyl amine to hindered amine light stabilizer is any ratio in the range of between about 1:0.5 to 1:5.
9 ) The composition of claim 2 further comprising a neutralizer.
10 ) An article of manufacture that is fabricated from a composition according to claim 2 .
11 ) A process for providing a sterilized article of manufacture which comprises the steps of:
a) providing an article according to claim 10; and
b) exposing said article to a source of radiation selected from the group consisting of: gamma radiation and electron beam radiation.
12 ) An article made by a process according to claim 11 wherein the propylene polymer is predominantly comprised of a random copolymer of propylene and ethylene, which random co-polymer contains between about 0.5% to about 8% of ethylene by weight based on the total weight of the polymer.
13 ) A composition according to claim 1 wherein an amine oxide is present, and wherein the ratio of amine oxide to hindered amine light stabilizer is any ratio in the range of between about 1:0.2 to 1:5.
14 ) A composition according to claim 1 wherein a hydroxyl amine is present, and wherein the ratio of hydroxyl amine to hindered amine light stabilizer is any ratio in the range of between about 1:0.5 to 1:5.
15 ) A composition according to claim 2 wherein the blend is present in any amount between about 500 ppm and 5000 ppm by weight based on the total weight of said polymer.
16 ) A composition according to claim 9 wherein the neutralizer comprises a hydrotalcite or a metallic stearate.
17 ) An article of manufacture according to claim 10 wherein the article is selected from the group consisting of:a syringe, a pouch, a film, a tube, a labware and a medical kit.
18 ) A process according to claim 11 wherein exposing said article to a source of radiation comprises exposing said article to a total amount of radiation which is no greater than about five megarads.