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EP-3867170-B1 - CONTAINERS FOR TRANSPORTING AND STORING LIQUID COMPOSITIONS

EP3867170B1EP 3867170 B1EP3867170 B1EP 3867170B1EP-3867170-B1

Inventors

  • DLUZNESKI, PETER, R.
  • PALYS, LEONARD H.
  • REYNAUD, Sara

Dates

Publication Date
20260506
Application Date
20191014

Claims (15)

  1. A container comprising a containment vessel comprised of a thermoset polymer, preferably a non-flammable thermoset polymer, characterised in that the container is configured to store and/or transport a liquid composition comprising at least one organic peroxide, wherein the container is provided with a vent mechanism, and wherein the thermoset polymer is comprised of at least one crosslinked thermoplastic polymer and has a torque value, as measured by ASTM D-5289-95, using a moving die rheometer and test conditions of 190°C, 100 cpm and 1°arc, of at least 7 dN·m and wherein the vent mechanism is configured such that it temporarily opens to relieve pressure within the containment vessel and then closes once the internal pressure drops back below a predetermined level, or is designed such that it remains open once a certain predetermined internal pressure is reached.
  2. The container of claim 1, wherein the thermoset polymer is comprised of at least one crosslinked polyethylene, preferably selected from the group consisting of crosslinked chlorinated polyethylenes; crosslinked low density polyethylenes; crosslinked linear low density polyethylenes; crosslinked high density polyethylenes; copolymers of ethylene with one or more comonomers selected from the group consisting of octene, heptene, hexene, pentene, butene, propene and combinations thereof; and blends thereof.
  3. The container of claim 1 or 2, wherein the at least one crosslinked thermoplastic polymer is obtained by reacting the thermoplastic polymer with one or more organic peroxides, optionally together with one or more coagents.
  4. The container of any of claims 1 to 3, wherein the containment vessel has an internal volume of 250 liters to 1500 liters.
  5. The container of any of claims 1 to 4, wherein the containment vessel is sufficiently transparent to permit external detection by the unaided human eye of the level of a liquid composition packaged within the containment vessel and/or has walls having an average thickness of 0.5 mm to 125 mm and/or is freestanding, foldable or collapsible when empty.
  6. The container of any of claims 1 to 5, wherein the container is additionally comprised of a protective cage at least partially surrounding the containment vessel and attached to or comprising a pallet.
  7. The container of any of claims 1 to 6, wherein at least part of the vent mechanism is integral with the containment vessel and/or the vent mechanism comprises a device selected from the group consisting of rupture disks, pressure release valves, pop off caps, rupture bolts, spring-loaded clamp rings, pressure relief portions comprised of a thermoplastic polymer which melts when heated, and pressure relief portions in the containment vessel wall which are sufficiently thin relative to the remainder of the containment vessel wall to accomplish controlled release of pressure within the containment vessel prior to reaching the rupture pressure of the containment vessel when the containment vessel is internally pressurized.
  8. The container of any of claims 1 to 7, wherein the containment vessel is additionally comprised of one or more additives selected from the group consisting of fillers, flame retardants, fire retardants, antioxidants, light stabilizers, internal and external mold release agents and combinations thereof.
  9. The container of any of claims 1 to 8, wherein the containment vessel has walls which consist of a single layer comprising the thermoset polymer or wherein the containment vessel has walls which comprise a plurality of layers with at least one of the layers comprising the thermoset polymer, the containment vessel having preferably walls which comprise a first layer comprised of a first thermoset polymer and a second layer comprised of a second thermoset polymer, wherein the first thermoset polymer and the second thermoset polymer are different from each other.
  10. The container of any of claims 1 to 9, further comprising at least one of a fill port or a dispensing tap.
  11. A packaged composition comprising a container in accordance with any of claims 1 to 10 and a liquid composition which is packaged within the container.
  12. The packaged composition of claim 11, wherein the liquid composition is comprised of at least one organic peroxide, preferably present in the composition in neat form, in solution form in combination with one or more solvents, or in aqueous emulsion form.
  13. A method of making a container in accordance with any of claims 1 to 10, comprising a step of forming the containment vessel by rotational molding, blow molding or three-dimensional printing.
  14. The method of claim 13, wherein a thermoplastic polymer is formed into a precursor structure for the containment vessel and the thermoplastic polymer of the precursor structure is thereafter subjected to crosslinking to convert the thermoplastic polymer into the thermoset polymer, thereby providing the containment vessel, wherein preferably crosslinking of the thermoplastic polymer is achieved by a method selected from the group consisting of reacting the thermoplastic polymer with one or more free radical initiators, optionally together with one or more coagents; moisture curing the thermoplastic polymer, wherein the thermoplastic polymer comprises silane groups; and radiation curing wherein the thermoplastic polymer is exposed to radiation.
  15. A method of packaging a liquid composition, comprising a step of introducing the composition into a container in accordance with any of claims 1-10.

Description

Field of the Invention The present invention relates to containers, in particular composite intermediate bulk containers that are adapted to hold liquid compositions, especially liquid compositions which are flammable or combustible or which comprise compounds such as organic peroxides that are susceptible to exothermic decomposition. The inventive containers exhibit improved safety characteristics as compared to conventional plastic composite intermediate bulk containers, in that they are able to endure fire engulfment for a specified period of time and under specified conditions without breaching. The present invention also provides methods of making such improved containers. Background Plastic composite intermediate bulk containers have been widely used in industry for many years for the storage and transport of various types of liquid compositions. Intermediate bulk containers (commonly referred to as IBCs), which typically have capacities of about 1000 or 1250 liters, are convenient to use where the quantity of a composition to be stored and/or transported is larger than can be accommodated in a 55 gallon drum but less than that which would fill a rail tank car or tanker truck. Plastic composite IBCs have a containment vessel constructed of a thermoplastic polymer, such as polyethylene, which is placed within a protective cage affixed to or containing a pallet. While thermoplastic polymers having satisfactory chemical and solvent resistance are available, such polymers are susceptible to softening and melting when the plastic composite IBC is exposed to high heat conditions (such as those encountered during a fire). Under such conditions, the plastic containment vessel may lose its structural integrity, causing its contents to be released. There have been several approaches to provide fire-resistance to plastic composite IBCs mentioned in the patent literature. Several patent documents (DE102015012163A, EP0986421A1, EP2979991A1, KR20170033332A, KR20180056711A, and US Pat. No. 5921420) focus on the use of a fire-resistant sheath that is placed completely around the IBC to insulate it from fire. Another approach mentioned in US Pat. No. 5924589, US Pat. No. 5984126, US Pat. Pub. No. 2016/0289566 A1, and US Pat. No. 7828995 B2 involves incorporating flame retardant additives into the plastic or painting the plastic with an intumescent coating that yields an insulating layer around the IBC in the event of a fire. A third approach mentioned in US9738441B2 utilizes built-in secondary containment to protect the IBC from fire and damage caused by mechanical moving devices such as forklifts. Containers particularly suitable for the packaging of compounds which are capable of undergoing exothermic decomposition, such as organic peroxides, are also known in the art. For example, U.S. Pat. No. 8,783,503 describes a packaged formulation comprising a compound liable to exothermic decomposition and optionally one or more organic diluents, wherein the formulation is packaged in a container with a volume of at least 250 liters provided with a vent to release gases and made from a thermoplastic material having a Vicat B softening temperature not higher than (a) the run-away temperature of the compound liable to exothermic decomposition if the formulation does not contain any diluent, or (b) the boiling temperature of at least 50 wt % of the total weight of diluent if the formulation does contain organic diluent. However, such packaging is not ideal since the entire contents of the container may be released in the event of a fire of sufficient temperature and duration to melt the thermoplastic material. Another approach is described in U.S. Pat. Publication No. 2012/0184685, which discloses stainless steel IBCs designed to contain liquid peroxide formulations and having a minimum vent area/volume ratio. Such stainless steel IBCs have certain disadvantages, however. They are relatively heavy, which adds to transportation costs and also makes them more difficult to move on-site. Moreover, such stainless steel IBCs are opaque; thus, it is not easy to monitor the level of liquid within them. Also, IBCs of this type are comparatively costly. US Pat. No. 4,857,257 and US Pat. Pub. No. 2017/0247534 describe the production of crosslinked rotomolded tanks using high density polyethylene (HDPE) homopolymer, linear low density polyethylene (LLDPE), and polyethylene copolymers containing various alpha olefin monomers. US Pat. No. 5,260,381 discloses a similar approach to make a rotomolded crosslinked tank that includes a small amount of ethylene vinyl acetate (EVA) polymer. US Pat No. 8,911,842 teaches a three layer tank containing an inner barrier layer which is not crosslinked and is encapsulated between two crosslinked layers. Documents WO2008/074006A1, DE9215689U1, DE10252745B3 and DE10161693A1 disclose further containers. It would be desirable to develop new types of containers that are useful for storing and transporting flamm