CLOSURE FOR A PRODUCT-RETAINING CONTAINER

Abstract

A closure for a product-retaining container is constructed for being inserted and securely retained in a portal-forming neck of said container. The closure comprises: a plastic material comprising at least one thermoplastic polymer; a plurality of particles comprising cork; and at least one processing aid. Optionally, one or more additives and/or blowing agents may be included. A method for manufacturing a closure comprises intimately combining multiple components, heating the resulting composition to form a melt, forming a closure precursor from the melt, and optionally cutting and/or finishing the closure precursor to form the closure.

Claims

1. A closure for a product-retaining container constructed for being inserted and securely retained in a portal-forming neck of said container, the closure comprising: (a) a plastic material comprising at least one thermoplastic polymer; (b) a plurality of particles comprising cork and having a particle size distribution D.sub.50 measured by means of mechanical sieving according to ISO ICS 19.120 in a range of from 0.2 mm to 10 mm; and (c) at least one processing aid.

2. The closure according to claim 1, wherein said closure comprises a plurality of cells.

3. The closure according to claim 2, wherein said plastic material comprises a polymer matrix comprising the plurality of cells.

4. The closure according to claim 2, wherein the plurality of cells comprises a plurality of substantially closed cells or a plurality of closed cells.

5. The closure according to claim 2, wherein the plurality of cells has an average cell size in a range of from about 0.025 mm to about 0.5 mm.

6. The closure according to claim 2, wherein at least one of a size or a distribution of the plurality of cells in the closure is substantially uniform throughout at least one of a length or a diameter of the closure.

7. The closure according to claim 3, wherein at least one cell of the plurality of cells in the polymer matrix is defined by at least one cell wall facing an interior of the at least one cell, wherein at least a part of the at least one cell wall comprises a plastic material, and the plastic material of the at least a part of the at least one cell wall comprises a different thermoplastic polymer composition compared to a plastic material forming a remainder of the polymer matrix.

8. The closure according to claim 1, wherein the closure has an overall density in a range of from 100 kg/m.sup.3 to 500 kg/m.sup.3.

9. The closure according to claim 1, wherein the plastic material has a foam density in a range of from 25 kg/m.sup.3 to 800 kg/m.sup.3.

10. The closure according to claim 1, wherein a distribution of the plurality of particles in the closure is substantially uniform throughout at least one of a length or a diameter of the closure.

11. The closure according to claim 1, wherein the plastic material is thermoplastically processable.

12. The closure according to claim 1, wherein the plastic material comprises at least one polymer that is biodegradable according to ASTM D6400.

13. The closure according to claim 1, wherein a portion of the closure in a range of from 50% by weight to 100% by weight of the closure is biodegradable according to ASTM D6400, based on a total weight of the closure.

14. The closure according to claim 1, wherein the plastic material comprises at least one thermoplastic polymer selected from the group consisting of: polyethylenes; metallocene catalyst polyethylenes; polybutanes; polybutylenes; thermoplastic polyurethanes; silicones; vinyl-based resins; thermoplastic elastomers; polyesters; ethylenic acrylic copolymers; ethylene-vinyl-acetate copolymers; ethylene-methyl-acrylate copolymers; thermoplastic polyolefins; thermoplastic vulcanizates; flexible polyolefins; fluorelastomers; fluoropolymers; polytetrafluoroethylenes; ethylene-butyl-acrylate copolymers; ethylene-propylene-rubber; styrene butadiene rubber; styrene butadiene block copolymers; ethylene-ethyl-acrylic copolymers; ionomers; polypropylenes; copolymers of polypropylene and ethylenically unsaturated comonomers copolymerizable therewith; olefin copolymers; olefin block copolymers; cyclic olefin copolymers; styrene ethylene butadiene styrene block copolymers; styrene ethylene butylene styrene block copolymers; styrene ethylene butylene block copolymers; styrene butadiene styrene block copolymers; styrene butadiene block copolymers; styrene isoprene styrene block copolymers; styrene isobutylene block copolymers; styrene isoprene block copolymers; styrene ethylene propylene styrene block copolymers; styrene ethylene propylene block copolymers; polyvinylalcohol; polyvinylbutyral; polyhydroxyalkanoates; copolymers of hydroxyalkanoates and monomers of biodegradable polymers; polylactic acid; copolymers of lactic acid and monomers of biodegradable polymers; aliphatic copolyesters; aromatic-aliphatic copolyesters; polycaprolactone; polyglycolide; poly(3-hydroxybutyrate); poly(3-hydroxybutyrate-co-3-hydroxyvalerate); poly(3-hydroxybutyrate-co-3-hydroxyhexanoate); poly(butylenesuccinate); poly(butylenesuccinate-co-adipate); poly(trimethyleneterephthalate); poly(butylenadipate-co-terephthalate); poly(butylenesuccinate-co-terephthalate); poly(butylenesebacate-co-terephthalate); lactic acid caprolactone lactic acid copolymers; lactic acid ethylene oxide lactic acid copolymers; polymers formed from monomer units selected from vinylidene chloride, acrylonitrile and methyl methacrylate; copolymers formed from two or more monomer units selected from vinylidene chloride, acrylonitrile and methyl methacrylate; and combinations of any two or more thereof.

15. The closure according to claim 1, wherein the plurality of particles comprises a plurality of cork particles.

16. The closure according to claim 1, wherein the plurality of particles has a particle size distribution D.sub.50 measured by means of mechanical sieving according to ISO ICS 19.120 in a range of from 0.5 mm to 5 mm.

17. The closure according to claim 1, wherein the plurality of particles is distributed homogeneously throughout the closure.

18. The closure according to claim 1, wherein the at least one processing aid comprises two or more processing aids.

19. The closure according to claim 1, wherein the at least one processing aid comprises a first processing aid that reduces a melt viscosity of the plastic material, and a second processing aid that reduces friction of the plastic material relative to at least one extruder surface during extrusion.

20. The closure according to claim 19, wherein the first processing aid is selected from the group consisting of: fatty acids; fatty acid esters; fatty acid amides; waxes; wax esters; ester waxes; plasticisers; alcohols; glycerol esters; polyol esters; polyol partial esters; polyglycol esters; fatty acid polyglycol esters; fatty acid polyglycol ethers; fatty alcohol polyglycol ethers; glycerol monostearate; metallic soaps; and combinations of any two or more thereof; and the second processing aid is selected from the group consisting of: fatty acids; fatty acid esters; fatty acid amides; fluoropolymers; polyols; silicones; glycerol esters; glycerol monostearate; polyol esters; polyol partial esters; polyglycol esters; fatty acid polyglycol esters; fatty acid polyglycol ethers; fatty alcohol polyglycol ethers; fatty acid esters of polyols; wax esters; ester waxes; metallic soaps; high molecular weight poly esters; and combinations of any two or more thereof.

21. The closure according to claim 1, wherein the at least one processing aid reduces a melt viscosity of the plastic material and reduces friction of the plastic material relative to at least one extruder surface during extrusion.

22. The closure according to claim 1, wherein at atmospheric pressure, the at least one processing aid is solid at temperatures up to 160 C.

23. The closure according to claim 1, wherein at atmospheric pressure, the at least one processing aid is at least partially in liquid form at temperatures above 50 C.

24. The closure according to claim 1, wherein the at least one processing aid is selected from the group consisting of: fatty acid derivatives derived from a saturated or unsaturated fatty acid having from 12 to 45 carbon atoms; modified fatty acid derivatives derived from a modified, saturated or unsaturated fatty acid having from 12 to 45 carbon atoms; natural waxes; synthetic waxes; fatty acids; fatty acid esters; fatty acid amides; waxes; wax esters; ester waxes; plasticisers; alcohols; glycerol esters; polyol esters; polyol partial esters; polyglycol esters; fatty acid polyglycol esters; fatty acid polyglycol ethers; fatty alcohol polyglycol ethers; metallic soaps; fluoropolymers; polyols; silicones; glycerol monostearate; fatty acid esters of polyols; high molecular weight poly esters; and combinations of any two or more thereof.

25. The closure according to claim 1, wherein the at least one processing aid comprises at least one of the following properties: (i) a dropping point measured according to ASTM D2265 in a range of from 50 C. to 160 C.; or (ii) a specific gravity in a range of from 0.900 to 1.300, measured according to ASTM D1298-12b.

26. The closure according to claim 1, wherein components (a), (b) and (c) are present in the following weight percent amounts, based on a total weight of the closure: (d) 10 wt. % to 59.9 wt. % of the plastic material; (e) 40 wt. % to 85 wt. % of the plurality of particles; and (f) 0.1 wt. % to 10 wt. % of the at least one processing aid.

27. The closure according to claim 1, comprising at least one of the following conditions (i) to (iv): (i) the closure is devoid of a binder; (ii) the closure is devoid of a crosslinking agent; (iii) the closure is devoid of a binder and is devoid of a crosslinking agent; or (iv) the plastic material is not crosslinked by means of a crosslinking agent.

28. The closure according to claim 1, wherein the closure is formed by a process comprising extrusion.

29. The closure according to claim 1, wherein the closure is formed by a process comprising monoextrusion.

30. The closure according to claim 1, wherein the closure has an oxygen ingress rate measured according to ASTM F1307 of less than about 3 mg oxygen per container in a first 100 days after the container is closed with the closure.

31. The closure according to claim 1, wherein the closure has an oxygen ingress rate measured according to ASTM F1307 selected from the group consisting of less than about 1 mg oxygen, less than about 0.5 mg oxygen, less than about 0.25 mg oxygen, less than about 0.2 mg oxygen, and less than about 0.1 mg oxygen, per container in a first 100 days after the container is closed with the closure.

32. The closure according to claim 1, wherein the closure has an oxygen transfer rate measured according to ASTM F1307 in 100% oxygen of less than 0.05 cc/day.

33. The closure according to claim 1, wherein the closure has a content of releasable trichloroanisole of less than 6 ng/L.

34. A closure system comprising the product-retaining container and the closure according to claim 1.

35. A composition for use in manufacturing a closure for a product-retaining container, the composition comprising: (a) a plastic material comprising at least one thermoplastic polymer; (b) a plurality of particles comprising cork and having a particle size distribution D.sub.50 measured by mechanical sieving according to ISO ICS 19.120 in a range of from 0.2 mm to 10 mm; (c) at least one processing aid; (d) optionally, at least one additive; and (e) at least one blowing agent.

36. The composition according to claim 35, wherein components (a), (b), (c), (d) and (e) are present in the following weight percent amounts, based on a total weight of the composition: (f) 10 wt. % to 59.8 wt. % of the plastic material; (g) 40 wt. % to 85 wt. % of the plurality of particles; (h) 0.1 wt. % to 10 wt. % of the at least one processing aid; (i) 0 wt. % to 10 wt. % of the at least one additive; and (j) 0.1 wt. % to 10 wt. % of the at least one blowing agent.

37. The composition according to claim 35, wherein the at least one blowing agent is selected from the group consisting of expandable microspheres, chemical blowing agents, physical blowing agents, and combinations of two or more thereof.

38. A method for obtaining a composition for use in manufacturing a closure for a product-retaining container, the method comprising intimately combining the following components: (a) a plastic material comprising at least one thermoplastic polymer; (b) a plurality of particles comprising cork and having a particle size distribution D.sub.50 measured by means of mechanical sieving according to ISO ICS 19.120 in a range of from 0.2 mm to 10 mm; (c) at least one processing aid; (d) optionally, at least one additive; and (e) at least one blowing agent.

39. The method according to claim 38, wherein the components (a), (b), (c), (d) and (e) are present in the following weight percent amounts, based on a total weight of the composition: (a) 10 wt. % to 59.8 wt. % of the plastic material; (b) 40 wt. % to 85 wt. % of the plurality of particles; (c) 0.1 wt. % to 10 wt. % of the at least one processing aid; (d) 0 wt. % to 10 wt. % of the at least one additive; and (e) 0.1 wt. % to 10 wt. % of the at least one blowing agent.

40. A composition obtainable by the method according to claim 38.

41. A method for manufacturing a closure for a product-retaining container constructed for being inserted and securely retained in a portal-forming neck of said container, said method comprising as method steps: i. intimately combining the following components, to form a composition: (a) a plastic material comprising at least one thermoplastic polymer; (b) a plurality of particles comprising cork and having a particle size distribution D.sub.50 measured by means of mechanical sieving according to ISO ICS 19.120 in a range of from 0.2 mm to 10 mm; (c) at least one processing aid; (d) optionally, at least one additive; and (e) at least one blowing agent; ii. heating the composition obtained in step i. to form a melt; iii. forming, by means of extrusion or molding, a closure precursor from the melt obtained in step ii.; and iv. optionally cutting and/or finishing the closure precursor to form the closure.

42. The method according to claim 41, wherein the at least one blowing agent is selected from the group consisting of expandable microspheres, chemical blowing agents, physical blowing agents, and combinations of two or more thereof.

43. The method according to claim 41, wherein during step ii. the plastic material is foamed.

44. The method according to claim 41, wherein the components (a), (b), (c), (d) and (e) are present in the following weight percent amounts, based on a total weight of the composition: (a) 10 wt. % to 59.8 wt. % of the plastic material; (b) 40 wt. % to 85 wt. % of the plurality of particles; (c) 0.1 wt. % to 10 wt. % of the at least one processing aid; (d) 0 wt. % to 10 wt. % of the at least one additive; and (e) 0.1 wt. % to 10 wt. % of the at least one blowing agent.

45. A closure obtained by the method according to claim 41.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0210] For a fuller understanding of the nature and objects of the present disclosure herein described, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

[0211] FIG. 1 is a perspective view of a closure according to an aspect of the present disclosure, comprising a peripheral layer;

[0212] FIG. 2 is a cross sectional-side elevation of a closure according to an aspect of the present disclosure, comprising a peripheral layer;

[0213] FIG. 3 is a perspective view of a closure according to an aspect of the present disclosure, not comprising a peripheral layer;

[0214] FIG. 4A is a photograph of an extruded closure according to an aspect of the present disclosure, not comprising a peripheral layer; and FIG. 4B is a photograph of a comparative extruded composition not according to an aspect of the present disclosure

DETAILED DESCRIPTION

[0215] By referring to the FIGURES, along with the following detailed disclosure, the construction and production method for the closures of the present disclosure can best be understood. In these Figures, as well as in the detailed disclosure herein, the closure of the present disclosure, is depicted and discussed as a bottle closure for wine products. However, as detailed herein, the present disclosure is applicable as a closure for use in sealing and retaining any desired product in any desired closure system. However, due to the stringent and difficult demands placed upon closures for wine products, the detailed disclosure herein focuses upon the applicability of the bottle closures of the present disclosure as a closure for wine bottles. However, it is to be understood that this detailed discussion is provided merely for exemplary purposes and is not intended to limit the present disclosure to this particular application and embodiment.

[0216] In FIGS. 1 and 2, the exemplary construction of a closure 20 is depicted comprising a generally cylindrical shape formed by core member 22 and peripheral layer 24 which peripherally surrounds and is intimately bonded to core member 22. In this aspect, core member 22 comprises a substantially cylindrically shaped surface 26, terminating with substantially flat end surfaces 27 and 28. Whenever applicable, the following detailed description of a closure having a layered structure, i.e. a core member and a peripheral layer, shall also apply to closures without a peripheral layer and also to multilayer closures having more than one peripheral layer.

[0217] In an exemplary aspect, peripheral layer 24 is intimately bonded directly to core member 22, peripherally surrounding and enveloping surface 26 of core member 22. Peripheral layer 24 incorporates exposed surface 29, which comprises a substantially cylindrical shape and forms the outer surface of bottle closure 20, along with surfaces 27 and 28 of the substantially flat terminating ends.

[0218] In order to assist in assuring entry of bottle closure 20 into the portal of the bottle into which closure 20 is inserted, terminating edge 31 may be beveled or chamfered. Similarly, terminating edge 32 may comprise a similar bevel or chamfer. Although any desired bevel or chamfered configuration can be employed, such as a radius, curve, or flat surface, it has been found that by merely cutting ends 31 and 32 with an angle of about 45 or about 60 the desired reduced diameter area is provided for achieving the desired effect. The chamfer angle and the chamfer length, i.e. the length of the chamfered surface as measured between surface 26, or surface 29 if a peripheral layer is comprised, are exemplarily within the ranges described herein for still wine closures or champagne closures.

[0219] By incorporating chamfered or beveled ends 31 and 32 on bottle closure 20, automatic self-centering is attained. As a result, when bottle closure 20 is compressed and ejected from the compression jaws into the open bottle for forming the closure thereof, bottle closure 20 is automatically guided into the bottle opening, even if the clamping jaws are slightly misaligned with the portal of the bottle. By employing this configuration, unwanted difficulties in inserting bottle closure 20 into any desired bottle are obviated. However, in applications which employ alternate stopper insertion techniques, chamfering of ends 31 and 32 may not be needed. Further, in order to facilitate the insertion of the closure into the bottle neck, the outer surface can fully or partly be coated with suitable lubricants, for example with silicones. Coating with a lubricant can be carried out by a variety of techniques known in the art, including tumbling and/or extrusion coating. For closures for champagne or sparkling wine, if a silicone lubricant is used a crosslinkable silicone is preferred since silicone can act as an antifoaming agent.

[0220] In order to produce the attributes suitable for use in the wine industry, core member 22 is formed from foam plastic material as described herein using a continuous extrusion process or a moulding process. Extrusion processes are preferred.

[0221] In FIG. 3, the exemplary construction of a closure 20 is depicted comprising a generally cylindrical shape formed by core member 22. In the exemplary aspect, core member 22 comprises a substantially cylindrically shaped surface 26, terminating with substantially flat end surfaces 27 and 28. In FIG. 3, closure 20 is shown without a peripheral layer. While closure 20 is depicted in FIG. 3 without a chamfered end, closure 20 can also be formed with chamfering.

[0222] FIG. 4A shows a monoextruded cylindrical closure 20 according to the present invention, comprising a core member 22 and no peripheral layer. The closure 20 is formed from a composition according to the present invention, by means of a method according to the present invention. The cork particles are visible at both the peripheral surface 26 and the end surfaces 27, 28. FIG. 4B shows an extrudate formed in the same extrusion equipment, using the same process parameters, as the closure of FIG. 4A. The composition of the extrudate of FIG. 4B is, however, not according to the invention. In particular, the composition of FIG. 4B does not include a processing aid according to the invention.

[0223] While the Figures show cylindrical closures, closures for sparkling wine bottles are also encompassed by the invention. Apart from having a different shape, the outer appearance of sparkling wine bottle closures according to the present invention is the same as the closure of FIG. 4A.

[0224] In order to demonstrate the efficacy of the present disclosure, samples of bottle closures 20, manufactured in accordance with the present disclosure and having a foamed core member, or a foamed core member and a solid peripheral layer, were produced and tested. In the absence of processing aid as defined herein, a significant degree of surface melt fracture could be observed if the same processing parameters were used. In addition, the density of a core member that could be achieved in the absence of processing aid, was around 500 kg/m.sup.3, whereas using processing aid according to the invention it was possible to achieve a core member density of 350 kg/m.sup.3. The closure produced according to the invention and comprising processing aid additionally has a lighter colour, giving an appearance closer to a high quality natural cork closure.

[0225] Any embodiment or aspect described or defined herein, whether defining a closure, a composition, or a method, may be combined with any other aspect or embodiment, or any features thereof, whether defining a closure, a composition, or a method, even when such a combination is not explicitly stated. All combinations of embodiments, aspects and features are within the scope of the present invention. In particular, any aspect of any claim may be combined with any aspect of any one of more claims. Where numerical ranges are defined, any numerical limit of any range may be combined with any other numerical limit of the same range. For example, an upper limit of a range may be combined with an upper limit of a range, or a lower limit of a range may be combined with a lower limit of a range, or an upper limit of a range may be combined with a lower limit of a range, while remaining within the scope of the present invention.

[0226] Test Methods:

[0227] The Mocon test for OTR/oxygen ingress rate was carried out using 100% oxygen according to ASTM F-1307.

[0228] Extraction Force:

[0229] The test for extraction force was carried out on a random sample selection according to the methods described in WO 03/018304 A1 (extraction test, p. 48, 1. 13p. 49, 1. 10), which are herewith incorporated and form part of the present disclosure. Three empty, clean Bordeaux style wine bottles were stoppered using a semi-automatic corking machine (Model 4040 from GAI S.p.A., Italy). The bottles were stored for one hour. The closures were then extracted at ambient temperature using a Dillon AFG-1000N force gauge (from Dillon/Quality Plus, Inc., USA) to measure the force required for extraction.

[0230] Surface Hardness:

[0231] The surface hardness is tested at room temperature (25 C.) using a Shore 902 automatic operating stand from Instron according to ASTM D2240-10.

[0232] Coefficient of Friction:

[0233] The dynamic coefficient of friction was measured according to ASTM D1894-14 at room temperature (25 C.) using an Instron Model 2810 Coefficient of Friction Testing Fixture. For the measurement of the dynamic coefficient of friction, a closure was split in half along its long axis and mounted to a steel plate with the flat side of the interior of the closure. This specimen was then loaded with 200 gram weight and pulled across a stainless steel surface at 15.2 cm/min.

[0234] Releasable haloanisole

[0235] The amount of haloanisole released from a cork into wine can be measured as so-called releasable haloanisole by soaking a cork or a sample of corks in a wine for 24 hours for an untreated cork or 48 hours for a treated cork, and measuring the amount of each haloanisole compound in the wine by means of gas chromatography. An acceptable level is generally considered to be one which results in an amount of the respective chloroanisole or chloroanisoles in the wine which is below the average sensory threshold of about 6ng/L for TCA or TBA.