CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. § 1 19(e) to U.S. Provisional Application No. 62/462,216 filed February 22, 2017, which application is incorporated by reference herein in its entirety.

BACKGROUND

This disclosure relates to plastic bag closures that can quickly and securely grip and hold close the necks of flexible bags. While a number of shapes and dimensions are possible, the plastic bag closures are generally small, thin, flat pieces of plastic. Figure 1 shows a bag closure (100) that includes a plastic body (1 10), a bag- holding central aperture (120), which is connected to a narrow access opening (130). The access opening (130) receives the neck of a flexible bag (not shown), which is then held within the central aperture (120).

Plastic bag closures are generally made from an extruded web or strip of a resinous material . U.S. Patent Nos 3, 164,249, 3, 164,250 and 4,333,566 describe forming bag closures from strips of multi-closures interconnected by breakable tabs. Individual bag closures can be separated (by breaking the tabs) and applied to flexible bags either manually or by automatic closure-applying machines. See U.S. Patent Nos. 4,999,969 and 4,911,293.

The dimensions of the conventional bag closures are such that they could be accidentally ingested by humans or pets and become lodged in the gastrointestinal track. Surgical removal of the ingested bag closure, when necessary, could be hindered due to the difficulty in locating the bag closure within the body. Thus, there is a need in the art for bag closures that can be readily detected by non-invasive imaging devices. BRIEF SUMMARY

Described herein are radiopaque bag closures that that are readily detectable by conventional imaging techniques such as radiography. Also described are radiopaque material based on radiopaque composite resins and use thereof.

One specific embodiment provides radiopaque bag closures comprising a flat resinous body having an access opening and a bag-holding central aperture, wherein the access opening joins the bag-holding central aperture to define a continuous space, and wherein the flat resinous body comprises a radiopaque composite resin having a carrier resin having one or more thermoplastic polymers and a radiopaque ceramic material dispersed in the carrier resin in a loading amount of 0.05-15% w/w. More typically, the loading amount is in the range of 0.1-10% w/w, or 0.1-5% w/w, or 0.2-5% w/w.

Another specific embodiment provides a radiopaque material based on a radiopaque composite resin having a carrier resin having one or more thermoplastic polymers and a radiopaque ceramic material dispersed in the carrier resin in a loading amount of 0.05-80% w/w. More typically, the loading amount is in the range of 0. J - 20%, or 0.1-10% w/w, or 0.1-5% w/w, or 0.2-5% w/w.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

construction according to one embodiment of the disclosure.

Figure 3 shows a radiopaque bag closure having a layered construction according to another embodiment of the disclosure.

Figure 4 shows a multi-closure strip according to one embodiment of the disclosure

DETAILED DESCRIPTION

Various embodiments of the present disclosure provide radiopaque bag closures made of a radiopaque composite resin that can be detected and visualized by

9 radiography. The radiopaque composite resin includes a carrier resin and a radiopaque ceramic material dispersed therein.

During production and usage, the radiopaque composite resin and bag closures must retain its rigidity yet having sufficient flex to allow machining of muiti- closure strips and closing of the bags in manual or automated settings. However, when inorganic fillers are mixed with an organic material (e.g., a carrier resin), the rheological properties, such as plasticity, of the carrier resin can be significantly altered, which in turn impact the handling (including machining) of the resulting composite resin.

Provided herein are bag closures formed of a radiopaque composite resin having a radiopaque ceramic material of high intrinsic radi opacity at a low loading amount. Advantageously, the radiopaque composite resin and the bag closures made thereof address the competing technical requirements of rigidity, plasticity and flexibility.

As used herein, a carrier resin refers to a host or matrix in which the radiopaque ceramic material is dispersed . The carrier resin includes one or more thermoplastic polymers.

A thermoplastic polymer can be any polymer material (including copolymers or blends of polymers) that is pliable, moldabie, extmdabie at a specific temperature and hardens after cooling from the specific temperature. Examples of thermoplastic polymers suitable for the present disclosure includes, without limitation, polyethylene (high or low density), polypropylene, polyvinyl chloride, polystyrene, a co-polymer of polystyrene (e.g., poly(acrylonitrile butadiene styrene), poly (butadiene- co-styrene)), nylons, polyacrylate, polyvinyl acetate, and the likes.

In preferred embodiments, the thermoplastic polymers are polyethylene- vinyl acetate), poly (butadiene-co-styrene) (e.g., high-impact polystyrenes or "HIPS"), poiy(ethylene-methaciylate), acrylonitrile butadiene styrene (ABS) or combinations thereof. Thermoplastic polymers typically have high molecular weight (e.g., MW

ΟΟ,ΟΟΟ Daltons). As used herein, a radiopaque ceramic material is an inorganic, non- metallic material that obstructs electromagnetic radiations (e.g., X-rays) and thus can be detected or visualized by a radiographic imaging device. Radiopacity refers to the relative inability of electromagnetic radiation to pass through a particular material. Thus, the radiopaque ceramic material has higher intrinsic radiopacity than the carrier resin. The carrier resin is typically considered radiolucent because it allows

electromagnetic radiations to largely pass through, e.g., in a substantially the same way as the soft tissues of the body.

The radiopaque ceramic material of the present disclosure preferably has high intrinsic radiopacity. At high radiopacity, the radiopaque ceramic material may be present at a low loading amount (percentage by mass relative to the carrier resin) yet still sufficient to be detectable. In various embodiments, the loading of the radiopaque ceramic material is typically in the range of 0.05-15% (w/w), 0.05-10% (w/w), 0.1-10% (w/w) or more typically, in the range of 0.1%-5% (w/w), 0.1%-2% (w/w), 0.2%-2% (w/w), 0.2-1.0%, or 0,2-0,5%.

Examples of the radiopaque ceramic material include inorganic compounds derived from zirconium, bismuth or ytterbium. Specific examples include, without limitation, zirconia (Zr0 ₂ ), bismuth oxychloride (BiOCl) and ytterbium (III) oxide (Yb ₂ 0 ₃ ).

The radiopaque ceramic material is typically in a particulate form to facilitate uniform blending within the carrier resin. Typically, the radiopaque ceramic material comprises micron-sized or submicron-sized particles. In various embodiments, the diameters of the particles of radiopaque ceramic material are in the range of 0.2- 20μιη. In other embodiments, the particles have mean diameters in a range of 1-10 μηι, 2-10 μιη, 2-5μιη or 1- μηι.

Additives such as plasticizers may be added to further fine-tune the rigidity and plasticity. Colorants or pigments may also be added.

The bag closures according to the present disclosures may be prepared by first extruding the radiopaque composite resin to provide a flat web or strip of a resinous body from which the bag closures are formed. The flat resinous body may be in a monolithic or a layered construction.

In a monolithic construction according to one embodiment, the entire resinous body of the bag closure is formed of a radiopaque composite resin. Figure 2 shows a bag closure in which the resinous body has a monolithic structure. As shown, a bag closure (200) has a resinous body (210) having a bag-holding central aperture (220) and an access opening (230), wherein the access opening joins the bag-holding central aperture to define a continuous space, and wherein the resinous body (210) is a monolithic layer of radiopaque composite resin (240) having a carrier resin and a radiopaque ceramic material at a loading amount of 0.05-15% w/w. Typically, the bag closure is about 0.03-0.09 inches thick. In a monolithic construction, the radiopaque composite resin extends the entire thickness of the bag closure.

In a layered construction, according to another embodiment, the resinous body of the bag closure is formed of a first radiopaque layer, a second radiopaque layer, and a non-radi opaque resinous layer intermediate of the first layer and the second layer. Advantageously, the non-radi opaque resinous layer forms the core or the bulk of the resinous body, which assumes the primary role in maintaining the necessary structural rigidity and plasticity. The radiopaque layers that sandwich the intermediate core layer impart the radiopacity needed for detection. In addition, the layered construction effectively reduces the total amount of the radiopaque ceramic material in the bag closure.

Figure 3 shows a bag closure in which the resinous body has a layered structure. As shown, a bag closure (300) has a layered resinous body (310) having a bag-holding central aperture (320) and an access opening (330), wherein the access opening joins the bag-holding central aperture to define a continuous space, and wherein the resinous body (310) comprises a first radiopaque layer of a first radiopaque composite resin (340) having a first carrier resin and a first radiopaque ceramic material at a loading amount of 0.05-15% w/w; a second radiopaque lay er of a second radiopaque composite resin (350) having a second carrier resin and a second radiopaque ceramic material at a loading amount of 0.05-15% w/w, and a non-radiopaque resinous layer (360) intermediate of the first radiopaque layer and radiopaque second layer.

In specific embodiments, the first radiopaque composite resin is identical to the second radiopaque composite resin, i.e., having the same carrier resin and the same the radiopaque ceramic material at the same loading amount. In further specific embodiment, the intermediate non-radiopaque resinous layer comprises the same carrier resin as that of the first and second radiopaque layers. Advantageously, the several layers are cohesively bonded together owing to the presence of the same carrier resin in each layer.

In various embodiments, the intermediate non-radiopaque resinous layer typically takes up 50-85%, or more typically, 60-80% by weight of the entire resinous body of the bag closure. Preferably though not essential, the remainder of the resinous body is divided evenly between the first radiopaque layer and the second radiopaque layer.

In a specific embodiment, the layered resinous body is composed of 10%

(w/w) of the first radiopaque layer, 10% (w/w) of the second radiopaque layer, and 80% of the intermediate non-radiopaque resinous layer.

The multi-layer bag closures typically are 0.03-0.09 inches thick, whereby the first and second radio opaque layers are about 0.003-0.009 inches thick, wherein the intermediate layer is about 0.024-0.072 inches thick.

As used herein, "about" refers to a range of values ±20% of a specifi ed value.

The bag closures of the present disclosures may be prepared by any of the methods disclosed U.S. Patent Nos 3, 164,249, 3, 164,250, 4,333,566 4,999,969 and 4,911,293 by using a radiopaque composite resin according to the present disclosure in the place of the conventional resins. Typically, the bag closures of the present disclosure may be prepared by extruding the radiopaque composite resin to form a flat resinous web of about 0.03-0.09 inches thick; forming one or more multi-closure strips from the flat resinous web, and separating individual bag closures from the multi- closure strip. One embodiment thus provides a multi-closure strip. Figure 4 shows a multi-closure strip (400) of a plurality of bag closures (200) (only two are shown). The bag closures (200) are the same as shown in Figure 2, except that the two adjacent bag closures (200) are connected by one or more tabs (240). These tabs can be broken off to cause separation of the bag closures (200) from one another. The tabs may be in any configurations so long as they can sustain the machining process and be broken off when a specific force is applied. See e.g., US 4,333,566.

Likewise, bag closures of a layered construction can be made from multi-closure strips of a layered construction, the several layers being simultaneously co-extruded to form a fiat resinous web of a layered structure, which can be machined into one or more multi-closure strips, and separated into individual bag closures.

In some embodiment, the radiopaque composite resin having the appropriate loading of the radiopaque ceramic material (hence the desire opacity) i s directly fed to the extruder.

In other embodiments, a bulk resinous material with a higher loading of radiopaque ceramic material and additional carrier resin are separately fed (from separate hoppers) at a predetermined let-down ratio, and the two are blended to provide the desired loading of the radiopaque ceramic materi al. In some embodiment, the bulk radiopaque composite resin may comprise up to a loading amount of 40-80%, or 50%- 80% of the radiopaque ceramic material . Blending of the two feeds provides a radiopaque composite resin having the desire radiopacity.

A further embodiment provides a radiopaque material based on a radiopaque composite resin. Such a material is broadly suitable for uses or applications in which radiopacity provides a means for detection. For instance, toys or toy parts are the most common foreign objects that can be accidentally ingested by children.

Detection of toys or toy parts with no metallic components (e.g., LEGO ^® bricks) can be challenging. Toys or toy parts made of the radiopaque material can be readily detected if ingested.

More specifically, the radiopaque material comprises a radiopaque composite resin having a carrier resin and 0.05-80% (or more typically 1-80%) of a radiopaque ceramic material includes one or more compounds derived from zirconium, bismuth or ytterbium.

In more specific embodiments, the carrier resin comprises one or more thermoplastic polymers, including for example, polyethylene (high or low density), polypropylene, polyvinyl chloride, polystyrene or a co-polymer thereof (e.g., poiyfacrylonitriie butadiene styrene), poly (butadiene-co-styrene)), nylons,

poiyacrylate, polyvinyl acetate, and the lik.es.

In further more specific embodiments, the radiopaque ceramic material is zirconia (Zr0 ₂ ), bismuth oxychioride (BiOCl), ytterbium (III) oxide (Yb ₂ 0 ₃ ), or a combinati on thereof.

The radiopaque material may further comprises additives such as one or more colorants, one or more plasticizers and the like. Additives may be combined with the radiopaque composite resin according to known methods in the art.

The various embodiments described above can be combined to provide further embodiments. All of the U.S, patents, U.S. patent application publications, U.S, patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the variou s patents, applications and publications to provide yet further embodiments.

These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible

embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.