Cap with barrier composition

Abstract

The present disclosure provides an article. In an embodiment the article is a cap and the cap includes a top portion and an annular sidewall extending from the top portion. The sidewall is composed of a barrier composition. The barrier composition includes (i) a low density polyethylene (LORE), and (ii) a nucleator. The sidewall has a water vapor transmission rate from 0.3 gm-mil / 100 in2 / 24 hr to less than or equal to 0.88 gm-mil / 100 in2 / 24 hr.

Description

CAP WITH BARRIER COMPOSITIONBACKGROUND

[0001] Plastic closures, plungers and caps for medical, nutraceuticals and probiotic containers and / or bottles can be made by injection molding. Known are polypropylene and polyethylene (PE) for use in plastic caps for medical bottles. Low density polyethylene ("LDPE") in particular meets the requirements of suitable melt strength, shear thinning, low extractables (hexane, xylene, others) and good processability for plastic bottle cap and injection molded part production. However, LDPE exhibits a high water vapor transmission rate which is detrimental for medical applications.

[0002] Thus, the art recognizes the need for LDPE with increased barrier properties, and a low water vapor transmission rate, in particular. Specifically, a need exists for LDPE with low water vapor transmission rate acceptable for medical applications, and acceptable for caps for medical bottles and / or caps for medical ampoules in particular.SUMMARY

[0003] The present disclosure provides an article. In an embodiment the article is a cap and the cap includes a top portion and an annular sidewall extending from the top portion. The sidewall is composed of a barrier composition. The barrier composition includes (i) a low density polyethylene (LDPE), and (ii) a nucleator. The sidewall has a water vapor transmission rate from 0.3 gm-mil / 100 in2 / 24 hr to less than or equal to 0.88 gm-mil / 100 in2 / 24 hr.DEFINITIONS

[0004] Any reference to the Periodic Table of Elements is that as published by CRC Press, Inc., 1990-1991. Reference to a group of elements in this table is by the new notation for numbering groups.

[0005] For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent U.S. version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure).

[0006] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., from 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two explicit values is included (e.g., the range 1-7 above includes subranges of from 1 to 2; from 2 to 6; from 5 to 7; from 3 to 7; from 5 to 6; etc.).

[0007] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight and all test methods are current as of the filing date of this disclosure.

[0008] The terms "blend" or "polymer blend," as used, refers to a mixture of two or more polymers. A blend may or may not be miscible (not phase separated at molecular level). A blend may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. The blend may be affected by physically mixing two or more polymers on the macro level (for example, melt blending resins or compounding), or the micro level (for example, simultaneous forming within the same reactor).

[0009] The term "composition" refers to a mixture of materials which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0010] The terms "comprising," "including," "having" and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of" excludes from the scope of any succeeding recitation any other component, step, or procedure, excepting those that are not essential to operability. The term "consisting of" excludes any component, step, or procedure not specifically delineated or listed. The term "or," unless stated otherwise, refers to the listed members individually as well as in any combination. Use of the singular includes use of the plural and vice versa.

[0011] An "ethylene-based polymer" is a polymer that contains more than 50 weight percent (wt%) polymerized ethylene monomer (based on the total amount of polymerizablemonomers) and, optionally, may contain at least one comonomer. Ethylene-based polymer includes ethylene homopolymer, and ethylene copolymer (meaning units derived from ethylene and one or more comonomers). The terms "ethylene-based polymer" and "polyethylene" may be used interchangeably.

[0012] The term "ethylene monomer," or "ethylene," as used herein, refers to a chemical unit having two carbon atoms connected with a double bond, and each carbon atom is bonded to two hydrogen atoms, wherein the chemical unit polymerizes with other such chemical units.

[0013] High density polyethylene (or "HDPE") is an ethylene homopolymer or an ethylene / a-olefin copolymer with at least one C4-C10 a-olefin comonomer, or at least one C4-C8 a-olefin comonomer and a density from 0.940 g / cc, or 0.945 g / cc, or 0.950 g / cc, 0.953 g / cc to 0.955 g / cc, or 0.960 g / cc, or 0.965 g / cc, or 0.970 g / cc, or 0.975 g / cc, or 0.980 g / cc.

[0014] The term "linear low density polyethylene," (or "LLDPE") as used herein, refers to a linear ethylene / a-olefin copolymer containing heterogeneous short-chain branching distribution comprising units derived from ethylene and units derived from at least one C3-C10 a- olefin, or C4-C8 a-olefin comonomer. LLDPE is characterized by little, if any, long chain branching, in contrast to conventional LDPE. LLDPE has a density from 0.910 g / cc to less than 0.940 g / cc. Nonlimiting examples of LLDPE include TUFLIN™ linear low density polyethylene resins (available from The Dow Chemical Company), DOWLEX™ polyethylene resins (available from the Dow Chemical Company), and MARLEX™ polyethylene (available from Chevron Phillips).

[0015] The term "low density polyethylene" (or "LDPE") may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene" and is an ethylene homopolymer and is typically produced by way of high pressure free radical polymerization ((> 100 MPa (for example, 100-400 MPa), tubular reactor or autoclave reactor with free radical initiator). LDPE resins typically have a density in the range of 0.915 to 0.935 g / cc. LDPE is distinct from LLDPE.

[0016] An "olefin" is an unsaturated, aliphatic hydrocarbon having a carbon-carbon double bond.

[0017] The term "polymer" or a "polymeric material," as used herein, refers to a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provides the multiple and / or repeating "units" or "mer units" that make upa polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The terms "ethylene / a-olefin polymer" and "propylene / a-olefin polymer" are indicative of copolymer as described above prepared from polymerizing ethylene or propylene respectively and one or more additional, polymerizable a- olefin monomer. It is noted that although a polymer is often referred to as being "made of" one or more specified monomers, "based on" a specified monomer or monomer type, "containing" a specified monomer content, or the like, in this context the term "monomer" is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to as being based on "units" that are the polymerized form of a corresponding monomer.

[0018] A "propylene-based polymer" is a polymer that contains more than 50 mole percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer.TEST METHODS

[0019] Density. Density is measured by the displacement (Archimedes) method, ASTM method D792 Method B. A sample is weighed in air (dry weight) and immersed in a fluid (wet weight). Knowing the density of the immersion fluid, the loss in weight of the sample on immersion allows the sample density to be calculated. A sheet of material is molded under per ASTM D4703 per Annex A.l Procedure C (15°C cooling). On removal from the press, 3 (three) coupons (~1.5" x ~0.5" x ~0.125") are cut from the sheet and density is measured. For Method B, the samples are weighed in air and then immersed in the fluid. The fluid (IPA, isopropyl alcohol) is contained in a double walled vessel and the temperature is controlled to 23°C + / - 0.1°C. The samples are allowed to soak in the fluid for 8 minutes to ensure the samples have equilibrated to the bath temperature. The samples are then weighed while still immersed in the fluid. A glass sinker of known dry weight and volume is then weighed while immersed in the fluid. The density of the immersion fluid is calculated from the known and measured values for the glass sinker (thiscorrects for any small deviations in the fluid density in the allowable temperature range). The density of the samples may then be calculated from the known fluid density and the measured wet and dry sample weights.

[0020] Triple Detector Gel Permeation Chromatography (TD-GPC). The chromatographic system consisted of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infra-red detector (IR5) and 4-capillary viscometer (DV) coupled to a Precision Detectors (Now Agilent Technologies) 2-angle laser light scattering (LS) detector Model 2040. For all absolute Light scattering measurements, the 15 degree angle is used for measurement. The autosampler oven compartment was set at 160^ Celsius and the column and detector compartment were set at 150^ Celsius. The columns used were 4 Agilent "Mixed A" 30cm 20-micron linear mixed-bed columns. The chromatographic solvent used was 1,2,4 trichlorobenzene (TCB) and contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters and the flow rate was 1.0 milliliters / minute.

[0021] Calibration of the GPC column set was performed with 21 narrow molecular weight distribution polystyrene standards with molecular weights ranging from 580 to 8,400,000 and were arranged in 6 "cocktail" mixtures with at least a decade of separation between individual molecular weights. The standards were purchased from Agilent Technologies. The polystyrene standards were prepared at 0.025 grams in 50 milliliters of solvent for molecular weights equal to or greater than 1,000,000, and 0.05 grams in 50 milliliters of solvent for molecular weights less than 1,000,000. The polystyrene standards were pre-dissolved at 802C with gentle agitation for 30 minutes then cooled and the room temperature solution is transferred cooled into the autosampler dissolution oven at lOO^C for 30 minutes. The polystyrene standard peak molecular weights were converted to polyethylene molecular weights using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)).:where M is the molecular weight, A has a value of 0.401 and B is equal to 1.0.

[0022] A fifth order polynomial was used to fit the respective polyethylene-equivalent calibration points.

[0023] The total plate count of the GPC column set was performed with decane which was introduced into blank sample via a micropump controlled with the PolymerChar GPC-IR system. The plate count for the chromatographic system should be greater than 18,000 for the 4 Agilent "Mixed A" 30cm 20-micron linear mixed-bed columns.

[0024] Samples were prepared in a semi-automatic manner with the PolymerChar "Instrument Control" Software, wherein the samples were weight-targeted at 2 mg / ml, and the solvent (contained 200ppm BHT) was added to a pre nitrogen-sparged septa-capped vial, via the PolymerChar high temperature autosampler. The samples were dissolved for 3 hours at 160^ Celsius under "low speed" shaking.

[0025] The calculations of Mn(CC), Mw(CC),and Mz(CC) were based on GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 2-4, using PolymerChar GPCOne™ software, the baseline-subtracted IR chromatogram at each equally-spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve for the point (i) from Equation 1.

[0026] In order to monitor the deviations overtime, a flowrate marker (decane) was introduced into each sample via a micropump controlled with the PolymerChar GPC-IR system. This flowrate marker (FM) was used to linearly correct the pump flowrate (Flowrate(nominal)) for each sample by RV alignment of the respective decane peak within the sample (RV(FM Sample)) to that of the decane peak within the narrow standards calibration (RV(FM Calibrated)). Any changes in thetime of the decane marker peak are then assumed to be related to a linear-shift in flowrate (Flowrate(effective)) for the entire run. After calibrating the system based on a flow marker peak, the effective flowrate (with respect to the narrow standards calibration) is calculated as Equation 5. Processing of the flow marker peak was done via the PolymerChar GPCOne™ Software. Acceptable flowrate correction is such that the effective flowrate should be within + / -0.S% of the nominal flowrate.Flowrate(effective) = Flowrate(nominal) * (RV(FM Calibrated) / RV(FM Sample)) (EQ5)

[0027] For the determination of the viscometer and light scattering detector offsets from the IR5 detector, the systematic Approach for the determination of multi-detector offsets is done in a manner consistent with that published by Balke, Mourey, et. al. (Mourey and Balke, Chromatography Polym. Chpt 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym. Chpt 13, (1992)), optimizing triple detector log (MW and IV) results from a linear homopolymer polyethylene standard (3.5 > Mw / Mn > 2.2) with a molecular weight in the range of 115,000 to 125,000 g / mol to the narrow standard column calibration results from the narrow standards calibration curve using PolymerChar GPCOne™ Software.

[0028] The absolute molecular weight data was obtained in a manner consistent with that published by Zimm (Zimm, B.H., J. Chem. Phys., 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, NY (1987)) using PolymerChar GPCOne™ software. The overall injected concentration, used in the determination of the molecular weight, was obtained from the mass detector area and the mass detector constant, derived from a suitable linear polyethylene homopolymer, or one of the polyethylene standards of known weight-average molecular weight. The calculated molecular weights (using GPCOne™) were obtained using a light scattering constant, derived from one or more of the polyethylene standards mentioned below, and a refractive index concentration coefficient, dn / dc, of -0.104. Generally, the mass detector response (IRS) and the light scattering constant (determined using GPCOne™) should be determined from a linear standard with a molecular weight in excess of about 50,000 g / mole. The viscometer calibration (determined using GPCOne™) can be accomplished using the methods described by the manufacturer, or, alternatively, by using the published values of suitable linear standards, such as Standard Reference Materials (SRM) 1475a(available from National Institute of Standards and Technology (NIST)). A viscometer constant (obtained using GPCOne™) is calculated which relates specific viscosity area (DV) and injected mass for the calibration standard to its intrinsic viscosity. The chromatographic concentrations are assumed low enough to eliminate addressing 2nd viral coefficient effects (concentration effects on molecular weight).

[0029] The absolute weight average molecular weight (MW(Abs)) is obtained (using GPCOne™) from the Area of the Light Scattering (LS) integrated chromatogram (factored by the light scattering constant) divided by the mass recovered from the mass constant and the mass detector (IR5) area. The molecular weight and intrinsic viscosity responses are linearly extrapolated at chromatographic ends where signal to noise becomes low (using GPCOne™). Other respective moments, Mn(abs), Mwjabs), and Mz(abs) are be calculated according to equations 6-8 as follows:

[0030] Cumulative Detector Fraction (CDF) Calculation Method

[0031] The calculation of the cumulative detector fraction from the internal infrared detector IR5 (CDFIR) is accomplished using the following steps:1). Linearly flow correct the chromatogram based on decane flow marker injection as described above.2). Calculate molecular weights from the IR5 measurement channel as described above.3). Calculate the cumulative detector of the IR5 (CDFIR) chromatogram (measurement channel) based on its baseline-subtracted peak height (H) from high to low molecular weight (low to high retention volume) at each data slice (j) according to Equation 9.

[0032] gpcBR Branching Index by TD-GPC

[0033] The gpcBR branching index is determined by first calibrating the light scattering, viscosity, and infrared IR5 detectors as described previously. Baselines are then subtracted from the light scattering, viscometer, and IR5 (measurement channel) chromatograms. Integration windows are then set to ensure integration of all of the low molecular weight retention volume range in the light scattering and viscometer chromatograms that indicate the presence of detectable polymer from the infrared (IR5) chromatogram. Linear polyethylene standards are then used to establish polyethylene and polystyrene Mark-Houwink constants. Upon obtaining the constants, the two values are used to construct two linear reference conventional calibrations for polyethylene molecular weight and polyethylene intrinsic viscosity as a function of elution volume, as shown in Equations (10) and (11):„ 1aPS+'LMPE- (— ~)aPE+ 1X MPSaPE+ 1(EQ10)KPE

[0034] The gpcBR branching index is a robust method for the characterization of long chain branching as described in Yau, Wallace W., "Examples of Using 3D-GPC— TREF for Polyolefin Characterization," Macromol. Symp., 2007, 257, 29-45. The index avoids the "slice-by-slice" TD- GPC calculations traditionally used in the determination of g' values and branching frequency calculations, in favor of whole polymer detector areas. From TD-GPC data, one can obtain the sample bulk absolute weight average molecular weight (MW( bs)) by the light scattering (LS) detector, using the peak area method. The method avoids the "slice-by-slice" ratio of lightscattering detector signal over the concentration detector signal, as required in a traditional g' determination.

[0035] With TD-GPC, sample intrinsic viscosities are also obtained independently using Equations (12). The area calculation in (12) offers more precision, because, as an overall sample area, it is much less sensitive to variation caused by detector noise and TD-GPC settings on baseline and integration limits. More importantly, the peak area calculation is not affected by the detector volume offsets. Similarly, the high-precision sample intrinsic viscosity ([q]) is obtained by the area method shown in Equation (12):where nsPistands for the specific viscosity as acquired from the viscometer detector.

[0036] To determine the gpcBR branching index, the light scattering elution area forthe sample polymer is used to determine the absolute molecular weight of the sample (MW(Abs)). The viscosity detector elution area for the sample polymer is used to determine the intrinsic viscosity ([q]) of the sample.

[0037] Initially, the molecular weight and intrinsic viscosity for a linear polyethylene standard sample, such as SRM1475a or an equivalent, are determined using the conventional calibrations ("cc") for both molecular weight and intrinsic viscosity as a function of elution volume, per Equations (3) and (13):

[0038] Equation (14) is used to determine the gpcBR branching index:wherein [q] is the measured intrinsic viscosity, [q]ccis the intrinsic viscosity from the conventional calibration, MW(Abs) is the measured weight average molecular weight, and Mw(cc) is the weight average molecular weight of the conventional calibration. The weight average molecular weight by light scattering (LS) is commonly referred to as "absolute weight average molecular weight".The Mw(cc) from Equation (3) using conventional GPC molecular weight calibration curve ("conventional calibration") is often referred to as "polymer chain backbone molecular weight," "conventional weight average molecular weight".

[0039] All statistical values with the "cc" subscript are determined using their respective elution volumes, the corresponding conventional calibration as previously described, and the concentration ( ). The values of "MW(Abs>" and "[h]" are measured values based on the mass detector, LALLS, and viscometer areas. The value of KPE is adjusted iteratively, until the linear reference sample has a gpcBR measured value of zero. For example, the final values for a and Log K for the determination of gpcBR in this particular case are 0.725 and -3.391, respectively, for polyethylene, and 0.722 and -3.993, respectively, for polystyrene. These polyethylene coefficients (0 and K) were then entered into Equation 14.

[0040] Once the K and a values have been determined using the procedure discussed previously, the procedure is repeated using the branched samples. The branched samples are analyzed using the final Mark-Houwink constants obtained from the linear reference as the best "cc" calibration values.

[0041] Melt Index. The term "melt index," or "Ml" as used herein, refers to the measure of how easily a thermoplastic polymer flows when in a melted state. Melt index, or 12, is measured in accordance with ASTM D 1238, Condition 190°C / 2.16 kg, Method B, and is reported in grams eluted per 10 minutes (g / 10 min).

[0042] Water transmission vapor rate (WVTR). The measurement of water vapor transmission rate (WVTR) is based on ASTM F1249. In this method, each test specimen in the form of a flat sheet is mounted and hermetically sealed (with the help of O-rings and high vacuum clear grease) in a diffusion cell. The diffusion cell consists of two chambers separated by the specimen. On one side of the cell, carrier gas (house nitrogen) flows into and out of the cell at a specified flow rate. The other side of the cell contains a sponge saturated with HPLC (high-performance liquid chromatography) grade water in order to create a 100% RH (relative humidity) environment. The water molecules permeate through the specimen and mix with the carrier gas. The carrier gas, after exiting the cell, goes through an infrared detector designed to produce an electric signal whose amplitude is proportional to the water vapor concentration in the carrier gas. The resultis given in terms of the amount of water vapor transmitted per unit area of the film per unit time. For WVTR, a typical unit after normalizing to thickness (often referred to as 'Permeation') is gm- mil / 100in2 / 24 hour (hr). The WVTR of a film sample is the equilibrated value read after several hours, when its difference relative to the last measurement is less than 1%. For the samples used in these studies, the MOCON instrument PERMATRAN-W Model 700 was used, and two specimens were used for each sample provided in the form of injection-molded sheets. The surface area of specimens exposed to permeation was 50 cm2, with a thickness of 1 mm and measurements were carried out at 100% Relative humidity and 37.8 °C.BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Fig. 1A is a perspective view of a cap in accordance with an embodiment of the present disclosure.

[0044] FIG. IB is a bottom perspective view of the cap of FIG. 1A.

[0045] FIG. 2 is a sectional view of a cap in accordance with another embodiment of the present disclosure.DETAILED DESCRIPTION

[0046] The present disclosure is directed to a cap. In an embodiment, the cap includes a top portion, and an annular sidewall extending from the top portion. The cap is composed of a barrier composition. The barrier composition is composed of (A) a low density polyethylene (LDPE), (B) a nucleator, and (C) optional additives. The sidewall has a water vapor transmission rate from 0.3 gm-mil / 100 in2 / 24 hr to less than or equal to 0.88 gm-mil / 100 in2 / 24 hr.

[0047] A plastic bottle cap (interchangeably referred to as a "cap"), as used herein, is a closure for a top of a bottle (or a closure for a bottom of a "tottle"), the cap made from a polymeric composition (either an ethylene-based polymer or a propylene-based polymer), the cap having a top portion and an annular sidewall extending from the top portion. The top portion may be circular in shape when viewed from top plan view. The cap may be injection molded. The top portion may or may not be integral to the annular sidewall. The cap may include additional structure such as threads, a spout, a hinge, and combinations thereof. Nonlimiting examples ofsuitable caps include a screw cap (threads present on interior and / or exterior sidewall surface), a child-proof cap (with mechanical structure for "push down and twist" safety opening of bottle), a flip top cap (cap hingedly attached to a base by way of hinge, such as a tube of shampoo, for example), a disc top cap (finger pressure downward on one side of the cap pops other side of cap upwards revealing a hole for releasing product), push / pull cap (a cap with a shaped nozzle, when nozzle is pulled upwards nozzle is extended to open, nozzle then releases the product, sports drink bottle, for example), twist top cap (a cap with a conical nozzle, the nozzle with a hole at the top, nozzle allows product to flow when user twists the nozzle to open the hole).

[0048] The cap includes a sidewall composed of a barrier composition. The barrier composition includes (A) a low density polyethylene (LDPE). The LDPE is an ethylene homopolymer having one, some, or all of the following properties:(i) a density from 0.910 g / cc to 0.930 g / cc; or from 0.920 g / cc to 0.930 g / cc, and / or(ii) a melt index from 15 g / 10 min to 30 g / 10 min, or from 18 g / 10 min to 28 g / 10 min; and / or(iii) Mw(abs) from 50,000 g / mol to 220,000 g / mol, or from 100,000 g / mol to 200,000 g / mol, and / or(iv) CDFiRfrom 0.010 to less than 0.060; and / or(v) a gpcBR value from 0.50 to 3.00, or from 1.00 to 2.50, or from 1.50 to 2.20; and / or(vi) a Mw(cc) / Mn(cc) from 2.50 to less than 9.00, or from 3.00 to 9.00, or from 4.00 to 8.00.

[0049] The barrier composition includes a nucleator. Nonlimiting examples of suitable nucleator include metal carboxylates, metal aromatic carboxylate, hexahydrophtalic acid metal salt, stearate, organic phosphate, sorbitol, bisamide, and any combination thereof.

[0050] In an embodiment, the nucleator is 1,2-cyclohexanedicarboxylic acid.

[0051] In an embodiment, the nucleator is blended, or is melt blended, with the LDPE by way of a nucleator masterbatch.

[0052] In an embodiment, the nucleator masterbatch includes HPN-20E (HPN-20E is 67 wt% ofcalcium salt of 1,2-cyclohexanedicarboxylic acid and 33 wt% of zinc stearate, based on the total weight of the HPN-20E). The nucleator masterbatch includes 3 wt% of HPN-20E, 1.5 wt% silica, 0.5 wt % hydrotalcite, 5 wt% of antioxidants, and 90 wt% weight percent of a carrier resin, based on total weight of the masterbatch. The carrier resin is a second ethylene-based polymer different than the LDPE.

[0053] In an embodiment, the second ethylene-based polymer for the masterbatch is a high- density polyethylene homopolymer (HDPE). The high-density polyethylene is an ethylene homopolymer (HDPE) with a narrow molecular weight distribution having a density from 0.945 g / cc to 0.970 g / cc, and a melt index from 4 g / 10 minutes to 15 g / 10 minutes. In a further embodiment, the sidewall (with or without the second ethylene-based polymer) is void of, or otherwise excludes, LLDPE.

[0054] The barrier composition may include one or more optional additives. Nonlimiting examples of suitable additives include antioxidants, ultraviolet light stabilizers, thermal stabilizers, slip agents, antiblock, pigments or colorants, processing aids, crosslinking catalysts, flame retardants, fillers, foaming agents, and combinations thereof. In an embodiment, the barrier composition includes 0 wt%, or from 0.5 wt% to 3 wt%, or from 1.0 wt% to 2.5 wt%, or from 1.0 wt% to 2.0 wt% total amount of additives. Weight percent is based on the total weight of the barrier composition.

[0055] In an embodiment, the cap with top portion and annular sidewall extending therefrom is a monolayer structure composed solely of the barrier composition, and the barrier composition comprises, consists essentially of, or consists of:(A) from 94 wt% to 99 wt%, or from 95 wt% to 98 wt% an LDPE ethylene homopolymer having one, some, or all of the following properties:(i) a density from 0.910 g / cc to 0.930 g / cc, and / or(ii) a melt index from 15 g / 10 min to 30 g / 10 min, or from 15 g / 10 min to 25 g / 10 min, or from 20 g / 10 min to 25 g / 10 min; and / or(iii) Mw(abs) from 50,000 g / mol to 220,000 g / mol, or from 100,000 g / mol to 200,000 g / mol, and / or(iv) CDFIR from 0.010 to less than 0.060, and / or(v) a gpcBR value from 0.50 to 3.00, or from 1.00 to 2.50, or from 1.50 to 2.20, and / or(vi) a Mw(cc) / Mn(cc) from 2.50 to less than 9.00, or from 3.00 to 9.00, or from 4.00 to 8.00.; and(B) from 0.01 wt% to 0.2 wt%, or from 0.05 wt% to 0.015 wt% of a nucleator that is 1,2-cyclohexanedicarboxylic acid;(C) 0 wt%, or from 0.1 wt% to 0.5 wt%, or from 0.2 wt% to 0.4 wt% additives; and(D) 0 wt%, or from 1 wt% to 5 wt%, or from 1.5 wt% to 4.5 wt% of a second polymer that is a HDPE wherein weight percent is based on total weight of the barrier composition; and the sidewall can have a varying thickness, and the sidewall has a WVTR from 0.3 gm- mil / 100 in2 / 24 hour (hr) to less than or equal to 0.88 gm-mil / 100 in2 / 24hr (hereafter sidewalll).

[0056] In an embodiment, the cap with top portion and annular sidewall extending therefrom is a monolayer structure composed solely of the barrier composition, and the barrier composition comprises, consists essentially of, or consists of:(A) from 94 wt% to 99 wt%, or from 95 wt% to 98 wt% of an LDPE ethylene homopolymer having one, some, or all of the following properties:(i) a density from 0.910 g / cc to 0.930 g / cc; and / or(ii) a melt index from 15 g / 10 min to 30 g / 10 min, or from 15 g / 10 min to 25 g / 10 min, or from 20 g / 10 min to 25 g / 10 min; and / or(iii) Mw(abs) from 50,000 g / mol to 220,000 g / mol, or from 100,000 g / mol to 200,000 g / mol; and / or(iv) CDFIR from 0.010 to less than 0.060; and / or(v) a gpcBR value from 0.50 to 3.00, or from 1.00 to 2.50, or from 1.50 to 2.20; and / or(vi) a Mw(cc) / Mn(cc)from 2.500 to less than 9.00, or from 3.00 to 9.00, or from 4.00 to 8.00; and / or(B) from 0.01 wt% to 0.2 wt%, or from 0.05 wt% to 0.15 wt% of a nucleator that is1,2-cyclohexanedicarboxylic acid;(C) additives of composed of(i) from 75 ppm to 1500 ppm silica; and(D) 0 wt%, or from 1 wt% to 5 wt%, or from 1.5 wt% to 4.5 wt% of a second polymer that is a HDPE wherein weight percent is based on the total weight of the barrier composition; and the sidewall has a varying thickness, the sidewall having a WVTR from 0.3 gm- mil / 100 in2 / 24 hour to less than or equal to 0.88 gm-mil / 100 in2 / 24 hour (hereafter sidewall2).

[0057] In an embodiment, a screw cap 10 is provided as shown in FIG. 1A and FIG. IB. Screw cap 10 includes a circular top portion 12 and an annular sidewall 14 extending from top portion 12. On an interior surface of sidewall 14 are threads 16 for threadedly affixing cap 10 to a bottle with a threaded top. Sidewall 14 (and optionally top portion 12) is / are composed of the present barrier composition ( / .e., LDPE, nucleator, and optional additives). In an embodiment, top portion 12 and sidewall 14 are a single integral piece such that top portion 12 and sidewall 14 (and thread 16) are composed solely of the present barrier composition ( / .e., LDPE, nucleator, and optional additives). Sidewall 14 may have a uniform thickness or may vary in thickness along a length of the sidewall. In an embodiment, sidewall 14 is a monolayer structure that is a continuous sidewall having no seams, sidewall 14 composed solely of the present barrier composition ( / .e., LDPE, nucleator, and optional additives). Sidewall 14 can have a varying thickness, and sidewall 14 has a WVTR from 0.3 gm-mil / 100 in2 / 24 hour to less than or equal to 0.88 gm-mil / 100 in2 / 24 hour.

[0058] In an embodiment, a cap 100 is provided as shown in FIG. 2. Cap 100 includes a circular top portion 112 and an annular sidewall 114 extending from top portion 112. On an interior surface of sidewall 114 are threads 116 for threadedly affixing cap 100 to a bottle 118 with a threaded neck 120. Cap 100 includes an annular inner wall 122 attached to, and extending from, an interior surface of top portion 112. Annular inner wall 122 has a closed distal end, so that annular inner wall 122 forms a closed chamber 124. In an embodiment, top portion 112, annular sidewall 114, and annular inner wall 122 each is composed solely of the present barriercomposition (i.e., LDPE, nucleator, and optional additives); and top portion 112, sidewall 114, and annular inner wall 122 each is a monolayer structure. Sidewall 114 can have a varying thickness, and sidewall 114 has a WVTR from 0.3 gm-mil / 100 in2 / 24 hour to less than or equal to 0.88 gm-mil / 100 in2 / 24 hour.

[0059] Annular inner wall 122 with closed distal end forms closed chamber 124. Within closed chamber 124 is an ingredient 126. Nonlimiting examples of ingredient 126 include active pharmaceutical ingredients and other pharmaceutical-use components. In this way, chamber 124 separates ingredient 126 from the contents of bottle 118 until a user is ready to release ingredient 126 from chamber 124 into the bottle and mix the ingredients with the contents of bottle 118.

[0060] By way of example, and not limitation, some embodiments of the present disclosure will now be described in detail in the following examples.EXAMPLES

[0061] Materials used in the examples are set forth in Table 1 below.

[0062] Table 1

[0063] Table la: Composition of nucleator masterbatch (MB1)

[0064] Table la

[0065] Table lb: Composition of nucleator masterbatch (MB2)

[0066] Table lb

[0067] LDPE and nucleator MB were melt blended with an 18 mm co-rotating twin screw extruder (TSE), model: Coperion ZSK 18 MEGAIab, (maximum: 1200 RPM, maximum specific torque: 18 Nm / cm3). The length over diameter ratio (L / D), and screw diameter over root diameter ratio (Do / Di) of this TSE are 40 and 1.55, respectively. The blended barrier compositions, listed in Table 2 (below), were injection molded using Sodick GL 100 injection molding machine into 4"x6" plaques of 1 mm thickness, replicating cap sidewall. The properties (i) of the initial LDPE (prior to blending with nucleator MB) and (ii) the WVTR for the sidewall for each sample cap (inventive examples ("IE") with present barrier composition) and comparative samples ("CS") are provided in Table 2 below.

[0068] Table 2: Cap Sidewall Propertiesto&LDPE properties prior to blending LDPE with nucleator MB NM = not measured

[0069] Applicant discovered that container top portion and sidewall composed of the unique LDPE (LDPE1-LDPE2) in combination with the nucleator exhibit low WVTR (0.3 gm-mil / 100 in2 / 24 hour to less than or equal to 0.89 gm-mil / 100 in2 / 24 hour). Bounded by no particular theory, the specific structural features of the unique LDPE in inventive examples IE1-IE2 that enabled low WVTR values include low levels for high MW tail (as quantified by CDFIR < 0.06), Mw(abs) (< 220,000) and gpcBr (< 3.0), and PDI (< 9) compared to comparative sample CS1. CS1 was deficient in at least one property and CS1 fails to provide a container with a cap and sidewall having a WVTR from 0.3 gm-mil / 100 in2 / 24 hr to less than equal to 0.88 gm-mil / 100 in2 / 24 hr.

[0070] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.

Claims

CLAIMS1. A cap comprising: a top portion; and an annular sidewall extending from the top portion, the sidewall composed of a barrier composition comprising(i) a low density polyethylene (LDPE), and(ii) a nucleator; and the sidewall has a water vapor transmission rate from 0.3 gm-mil / 100 in2 / 24 hr to less than or equal to 0.88 gm-mil / 100 in2 / 24 hr.

2. The cap of claim 1 wherein the LDPE has a property selected from the group consisting of(i) a density from 0.910 g / cc to 0.930 g / cc,(ii) a melt index from 15 g / 10 min to 30 g / 10 min,(iii) Mw(abs) from 50,000 g / mol to 220,000 g / mol,(iv) CDFIR from 0.010 to less than 0.060,(v) a gpcBR value from 0.50 to 3.00,(vi) a Mw(cc) / Mn(cc) from 2.50 to less than 9.00, and(vii) combinations thereof.

3. The cap of any of claims 1-2 wherein the nucleator is selected from the group consisting of a metal carboxylate, a metal aromatic carboxylate, a hexahydrophthalic acid metal salt, a stearate, an organic phosphate, a sorbitol, a bisamide, and combinations thereof.

4. The cap of any of claims 1-3 wherein the barrier composition further comprises a second ethylene-based polymer different than the LDPE.

5. The cap of any of claims 1-4 wherein the barrier composition comprises silica.

6. The cap of any of claims 1-5 comprising from 94 wt% to 99 wt% of the LDPE; from 100 ppm to 2000 ppm of the nucleating agent that is 1,2-cyclohexanedicarboxylic acid; from 1 wt% to 5 wt% of the second ethylene-based polymer that is a high density polyethylene; from 75 ppm to 1500 ppm silica.

7. The cap of any of claims 1-6 wherein the top portion and the sidewall form an integral piece composed solely of the barrier composition.

8. The cap of any of claims 1-7 wherein the sidewall is a monolayer structure and has a thickness for 0.1 mm to 20 mm.

9. The cap of any of claims 1-8 wherein the cap comprises an annular inner wall attached to, and extending from, an interior surface of the top portion; and the annular inner wall has a closed distal end and defines a closed chamber.

10. The cap of claim 9 wherein an ingredient is present in the closed chamber.

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