# US 12,760,175 B2 · Polyoxymethylene polymer composition for rotational molding applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,760,175 B2 - Document ID: US12760175B2 - Status: Granted - Kind: B2 - Application number: 17/721,682 - Filed: 2022-04-15 - Published: 2022-11-10 - Granted: 2026-10-13 - Earliest claimed: 2021-04-16 - Assignees: Celanese International Corporation - Applicants: Celanese International Corporation - Inventors: Darin Grinsteinner - Web page: https://patentgrep.com/patent/US12760175B2 ## CPC - C08L 59/02: Polyacetals containing polyoxymethylene sequences only - B65D 1/18: of polygonal cross-section - B65D 25/42: Integral or attached nozzles or spouts - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2205/035: containing four or more polymers in a blend - C08L 2207/04: Thermoplastic elastomer - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES ## Abstract A polymer composition containing a polyoxymethylene polymer in the form of particles for rotational molding applications is disclosed. The polyoxymethylene polymer is selected to have physical characteristics and is combined with one or more impact modifiers in order to produce hollow vessels and other articles having improved physical properties, such as impact strength resistance. ## Claims ### Claim 1 A container for fuels comprising: a seamless rotational molded housing defining an opening configured to receive a fluid, the housing including an interior enclosure surrounded by a wall and wherein the wall is made from a polymer composition comprising: a) a polyoxymethylene polymer having a melt flow rate of less than 4 g/10 min, wherein the polyoxymethylene polymer contains hydroxyl groups, the hydroxyl groups being present in an amount less than 10 mmol/kg; b) one or more impact modifiers being present in the polymer composition in an amount of from 4% by weight to 27% by weight, an impact modifier of the one or more impact modifiers having a melting temperature within 5° C. of a melting temperature of the polyoxymethylene polymer, the one or more impact modifiers comprising a thermoplastic copolyester elastomer, the thermoplastic copolyester elastomer comprising a block copolymer of polybutylene terephthalate and polyether segments; c) a polyalkylene glycol, the polyalkylene glycol being present in the polymer composition in an amount from 0.1 wt. % to 1 wt. %; and d) an ultraviolet light absorber, the ultraviolet light absorber being present in the polymer composition in an amount from 0.25 wt. % to 1 wt. %; wherein the wall of the housing has a normalized permeation of less than 4 g-mm/m2 per day at 40° C. according to SAE Test J2665. ### Claim 2 (depends on 1) The container as defined in claim 1, wherein the polyoxymethylene polymer has a melt flow rate of less than 4 g/10 min and greater than 0.5 g/10 min. ### Claim 3 (depends on 1) The container as defined in claim 1, wherein the one or more impact modifiers further comprises a thermoplastic polyurethane elastomer. ### Claim 4 (depends on 1) The container as defined in claim 1, wherein the wall of the container has a normalized permeation of less than 3.5 g-mm/m2 per day at 40° C. ### Claim 5 (depends on 1) The container as defined in claim 1, wherein the container has a multiaxial impact of greater than 7.5 ftlb-f at 23° C. ### Claim 6 (depends on 1) The container as defined in claim 1, wherein the wall has a thickness of from 0.5 mm to 10 mm. ### Claim 7 (depends on 1) The container as defined in claim 1, wherein the wall of the housing has a permeation of less than 1 g/m2/day when tested according to US EPA Test 40 CFR Part 1060.520. ### Claim 8 (depends on 1) The container as defined in claim 1, wherein the wall of the housing displays a stabilization parameter of greater than 0.96 when tested according to US EPA Test 40 CFR Part 1060.520 when tested at 28° C. and for a soak duration of ten weeks. ### Claim 9 (depends on 1) The container as defined in claim 1, wherein the container comprises a fuel tank, a hydraulic oil tank, a compressed gas tank, a water tank, or a diesel exhaust fluid tank. ### Claim 10 (depends on 1) The container as defined in claim 1, wherein the polymer composition is free of any nitrogen-containing formaldehyde scavengers. ### Claim 11 (depends on 1) The polymer composition as defined in claim 1, wherein the polymer composition comprises a nucleating agent in an amount from 0.1 wt. % to 1.5 wt. %. ### Claim 12 (depends on 1) The polymer composition as defined in claim 1, wherein the melting temperature of the impact modifier is less than the melting temperature of the polyoxymethylene polymer. ### Claim 13 (depends on 12) The polymer composition as defined in claim 12, wherein: the polyalkylene glycol has a molecular weight from 2000 g/mol to 8,000 g/mol; the polymer composition further comprises an acid scavenger in an amount from 0.01 wt. % to 1 wt. %; and the polyoxymethylene polymer is present in the polymer composition in an amount from 60 wt. % to 80 wt. %.