# US 12,006,424 B2 · Polymer composition suitable for gamma-ray sterilization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,424 B2 - Document ID: US12006424B2 - Status: Granted - Kind: B2 - Application number: 17/288,668 - Filed: 2019-10-23 - Published: 2021-12-23 - Granted: 2024-06-11 - Earliest claimed: 2018-10-30 - Assignees: Borealis AG - Applicants: Borealis AG - Inventors: Jingbo Wang; Markus Gahleitner; Klaus Bernreitner - Web page: https://patentgrep.com/patent/US12006424B2 ## CPC - C08L 23/12: Polypropene - A61L 2/081: Gamma radiation - C08K 5/005: {Stabilisers against oxidation, heat, light, ozone} - C08K 5/0083: {Nucleating agents promoting the crystallisation of the polymer matrix} - C08K 5/01: Hydrocarbons {(C08K5/0091 takes precedence)} - C08K 5/1575: Six-membered rings - C08K 5/526: with hydroxyaryl compounds - A61L 2103/23: {Containers other than laboratory or medical, e.g. bottles or mail} - C08F 4/65908: {in combination with an ionising compound other than alumoxane, e.g. (C6F5)4B-X+} - C08F 4/65912: {in combination with an organoaluminium compound} - C08F 110/06: Propene - C08F 2420/07: Heteroatom-substituted Cp, i.e. Cp or analog where at least one of the substituent of the Cp or analog ring is or contains a heteroatom - C08L 2201/08: Stabilised against heat, light or radiation or oxydation - C08L 2203/02: for biomedical use - C08L 2203/10: used for bottles - C08L 2205/24: Crystallisation aids - C08L 2310/00: Masterbatches - C08L 2314/06: Metallocene or single site catalysts - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - 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 (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract The present invention is directed to a polymer composition (C) comprising a first propylene homopolymer (H-PP), at least one hydrocarbon oil, at least one nucleating agent and at least one antioxidant, a moulded article formed from said polymer composition, a process for gamma-ray sterilization of said moulded article and uses of hydrocarbon oil in said polymer composition for improving resistance to gamma-ray radiation and reducing discoloration after gamma-ray sterilization in said polymer composition. ## Claims ### Claim 1 A polymer composition (C), comprising, based on the total weight of the polymer composition (C): (a) 91.0 to 98.0 wt.-% of a propylene homopolymer (H-PP), (b) 1.98 to 8.98 wt.-% of at least one hydrocarbon oil (WO), (c) 0.01 to 0.7 wt.-% of at least one nucleating agent (NA), and (d) 0.01 to 2.0 wt.-% of at least one antioxidant (AO); wherein the sum of components (a), (b), (c) and (d) adds up to at least 95 wt.-% of the total weight of the polymer composition (C) and the propylene homopolymer (H-PP) is an isotactic propylene homopolymer defined by (i) a melt flow rate MFR2 determined according to IS01133 at 230 ° C. and 2.16 kg in the range from 4.0 to 22.0 g/10 min; (ii) a melting temperature in the range of 145 to 162° C. as determined by differential scanning calorimetry (DSC); and (iii) a content of 2,1 erythro regio-defects in the range from 0.1 to 1.3 mol % as determined by 13C-NMR spectroscopy. ### Claim 2 (depends on 1) The polymer composition (C) according to claim 1, having a melt flow rate MFR2 determined according to IS01133 at 230° C. and 2.16 kg in the range from 5.0 to 25.0 g/10 min. ### Claim 3 (depends on 1) The polymer composition (C) according to claim 1, wherein the propylene homopolymer (H-PP) has a polydispersity (Mw/Mn) in the range from 2.0 to 4.5 as determined by GPC according to ISO 16014. ### Claim 4 (depends on 1) The polymer composition (C) according to claim 1, wherein the propylene homopolymer (H-PP) is prepared in the presence of a metallocene catalyst. ### Claim 5 (depends on 1) The polymer composition (C) according to claim 1, wherein the propylene homopolymer (H-PP) is characterized by a high isotacticity, defined as pentad regularity of more than 96.0 mol % as determined by 13C-NMR spectroscopy. ### Claim 6 (depends on 1) A moulded article comprising at least 90 wt. % of the polymer composition (C) as defined in claim 1, based on the total weight of the moulded article. ### Claim 7 (depends on 6) The moulded article according to claim 6 being a medical, pharmaceutical or diagnostic article. ### Claim 8 (depends on 6) The moulded article according to claim 6, which has been gamma-ray sterilized at a dose of at least 15 kGy. ### Claim 9 (depends on 6) The moulded article according to claim 6, having an overall migration in the polymer composition (C) as determined according to EN ISO 1186-14:2002 on injection moulded plaques, 60×60×1 mm3 of less than 60.0 mg/dm2. ### Claim 10 (depends on 6) The moulded article according to claim 6, having a discoloration of the polymer composition (C) after gamma-ray sterilization at 50 kGy and 60 days of aging as defined by yellowness index of not higher than 23 as determined on injection moulded plaques 60×60×1 mm3 according to standard method ASTM E313. ### Claim 11 (depends on 6) The moulded article according to claim 6, having a Charpy notched impact strength in the range of 2.5 to 15.0 kJ/m2, as determined according to ISO 179 1 eA, and a retention of said impact strength after gamma-ray sterilization at 50kGy and 60 days of aging of more than 75%. ### Claim 12 (depends on 6) A process for gamma-ray sterilization of articles comprising the steps of: providing the moulded article as defined by claim 6, and subjecting said moulded article to gamma-ray sterilization. ### Claim 13 (depends on 12) The process according to claim 12, wherein the gamma-ray sterilization is carried out at a dose in the range of 15 to 150 kGy.