阅读说明：本技术 用于气味抑制的组合物 (Compositions for odor suppression ) 是由 A·L·克拉索夫斯基 孙科夫 K·路 S·T·麦特斯 A·威廉森 J·E·鲁伊斯 H·辛 于 2019-02-22 设计创作，主要内容包括：本公开提供一种组合物。在一实施例中,所述组合物包括(A)85wt％到99wt％的基于烯烃的聚合物和(B)15wt％到1wt％的气味抑制剂。所述气味抑制剂为(i)氧化锌的粒子和(ii)锌离子聚合物的掺混物。所述氧化锌粒子具有100nm到3000nm的D50粒径、1m<Sup>2</Sup>/g到9m<Sup>2</Sup>/g的表面积和小于0.020m<Sup>3</Sup>/g的孔隙度。如根据ASTM D5504-12所测量,所述组合物在3天时具有小于70的甲硫醇气味抑制值。(The present disclosure provides a composition. In one embodiment, the composition includes (a)85 to 99 wt% of an olefin-based polymer and (B)15 to 1 wt% of an odor inhibitor. The odor inhibitor is a blend of (i) particles of zinc oxide and (ii) a zinc ionomer. The zinc oxide particles have a D50 particle size of 100nm to 3000nm, 1m 2 G to 9m 2 Surface area of less than 0.020 m/g 3 Porosity in g. The combination is measured according to ASTM D5504-12The material has a methyl mercaptan odor inhibition value of less than 70 at 3 days.)

1. A composition, comprising:

(A)85 to 99 wt% of an olefin-based polymer;

(B)15 to 1 wt% of an odor inhibitor comprising a blend of:

(i) particles of zinc oxide having a D50 particle size of 100 to 3000nm, 1m²G to 9m²Surface area of less than 0.020 m/g³Porosity in/g;

(ii) a zinc ion polymer, and

the composition has a methyl mercaptan odor inhibition value of less than 70 at 3 days as measured according to ASTM D5504-12.

2. The composition of claim 1, wherein the olefin-based polymer is an ethylene-based polymer exclusive of other polymers.

3. The composition of claim 2, wherein the ethylene-based polymer is LLDPE.

4. The composition of any one of claims 1 to 3, wherein composition comprises 0.1 wt% to 9 wt% zinc.

5. The composition of claim 4, wherein the zinc is present and excludes group 5 to group 12 metals.

6. The composition of any one of claims 1 to 5, wherein the weight% ratio between zinc oxide (Bi) and zinc ionomer (Bii) is 3:1 to 1:7, based on the total weight of the odor inhibitor.

7. The composition of claim 6, wherein the weight% ratio between B (i) and B (ii) is from 1:3 to 1:7, based on the total weight of the odor inhibitor.

8. The composition of claim 7, wherein the odor inhibitor is present in an amount of 1 wt% to 10 wt%, based on the total weight of the composition.

9. The composition of any one of claims 7 to 8, wherein the particles of zinc oxide (Bi) have a D50 particle size of 100nm to 3000 nm;

1.0m²g to 5.0m²Surface area per gram;

0.010m³g to 0.015m³Porosity in/g; and is

The composition has a methyl mercaptan odor inhibition value of less than or equal to 55 at 3 days.

10. The composition according to claim 9, wherein the composition comprises a continuous phase constituted by the ethylene-based polymer and a discontinuous phase constituted by regions of the zinc oxide particles (Bi) embedded in the zinc ionomer (Bii).

11. The composition of claim 9, wherein the domains have an average diameter of 500nm to 10,000 nm.

12. The composition of any one of claims 1 to 11, wherein the zinc ionomer is a zinc salt of a polymer selected from the group of: ethylene/methyl-methacrylic acid, ethylene/vinyl acrylic acid, ethylene/methacrylic acid ester, ethylene/n-butyl acrylic acid and ethylene acrylic acid.

13. The composition of any one of claims 1 to 12, wherein the zinc ionomer is a zinc salt of an ethylene/acrylic acid copolymer.

Background

Many uses of articles made from olefin-based polymers suffer from unpleasant odors. A common source of unpleasant odor includes the emission of hydrogen sulfide (H)₂S) and thiol-containing compositions. It is desirable in many applications to be able to remove or otherwise suppress the odor of olefin-based polymer articles. Thus, there is a need in many industries to be able to remove sulfur-based odorants (e.g., H) from a gas phase₂S, thiol (mercaptan)) and thiol (thiol). A common example is the ability of plastic garbage bag liners (i.e., olefin-based polymer articles) to remove odors.

Zinc oxide (ZnO) particles and zinc salts are known to consume a number of odor-causing molecules, such as H₂S and a thiol. All other factors being equal, it is well known that ZnO concentration is in direct phase with odor suppressionOff-i.e., as the ZnO concentration increases in a given olefin-based polymer article, the effectiveness of odor suppression also increases.

Although odor suppression increases with increasing ZnO, there is still a limit to the amount of ZnO that can be effectively incorporated into olefin-based polymer articles. In the production of blown film trash can liners, for example, highly loaded ZnO particles increase extrusion die lip fouling, causing film defects. The highly loaded ZnO particles also increase haze, resulting in a decrease in the transparency of the olefin-based polymer film and/or a deterioration in the color of the film. The highly loaded ZnO particles also adversely affect mechanical properties such as impact strength and film tear strength. Thus, processing parameters and end-use mechanical requirements impose practical limitations on the loading of ZnO particles into olefin-based polymer compositions.

Thus, there is a need for olefin-based polymer compositions having improved odor suppression while carrying suitable zinc loadings in order to maintain processability, desired optical properties, and desired mechanical properties for end-use applications. There is a further need for odor-inhibiting articles made from such olefin-based polymer compositions.

Disclosure of Invention

The present disclosure provides a composition. In one embodiment, the composition includes (a)85 to 99 wt% of an olefin-based polymer and (B)15 to 1 wt% of an odor inhibitor. The odor inhibitor is a blend of (i) particles of zinc oxide and (ii) a zinc ionomer. The zinc oxide particles have a D50 particle size of 100nm to 3000nm, 1m²G to 9m²Surface area of less than 0.020 m/g³Porosity in g. The composition has a methyl mercaptan odor inhibition value of less than 70 at 3 days as measured according to ASTM D5504-12.

Definition of

Any reference to the periodic table of elements is the periodic table of elements published by CRC Press, inc., 1990-1991. Reference to the element groups in this table is made by numbering the new symbols of the groups.

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 the equivalent us version thereof is so incorporated by reference), especially with respect to the definitions in the art (to the extent not inconsistent with any definitions specifically provided in this disclosure) and the disclosure of common general knowledge.

The numerical ranges disclosed herein include all values from the lower and upper values, and include both the lower and upper values. For ranges containing exact values (e.g., 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two exact values is included (e.g., 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6, etc.).

Unless stated to the contrary, implied from the context, or customary in the art, all parts and percentages are by weight and all test methods are current as of the filing date of this disclosure.

An "agglomerate" is a plurality of individual fine solid particles that agglomerate or otherwise collectively form a single mass.

As used herein, the term "blend" or "polymer blend" is a blend of two or more polymers. Such blends may or may not be miscible (not phase separated at the molecular level). Such blends may or may not be phase separated. Such blends may or may not contain one or more region configurations, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art.

The term "composition" refers to a mixture of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

The terms "comprising," "including," "having," and derivatives thereof, are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is specifically disclosed. For the avoidance of any doubt, unless stated to the contrary, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise. In contrast, the term "consisting essentially of … …" excludes any other components, steps, or procedures from any subsequently enumerated range, except for those that are not essential to operability. The term "consisting of … …" excludes any component, step, or procedure not specifically recited or listed. Unless otherwise specified, the term "or" refers to the listed members individually as well as in any combination. The use of the singular includes the use of the plural and vice versa.

An "ethylene-based polymer" is a polymer containing greater than 50 weight percent (wt%) polymerized ethylene monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Ethylene-based polymers include ethylene homopolymers and ethylene copolymers (meaning units derived from ethylene and one or more comonomers). The terms "ethylene-based polymer" and "polyethylene" are used interchangeably. Non-limiting examples of ethylene-based polymers (polyethylenes) include Low Density Polyethylene (LDPE) and linear polyethylenes. Non-limiting examples of linear polyethylenes include Linear Low Density Polyethylene (LLDPE), Ultra Low Density Polyethylene (ULDPE), Very Low Density Polyethylene (VLDPE), multicomponent ethylene-based copolymer (EPE), ethylene/a-olefin multi-block copolymer (also known as Olefin Block Copolymer (OBC)), substantially linear or linear plastomer/elastomer, and High Density Polyethylene (HDPE). In general, polyethylene can be produced in a gas phase fluidized bed reactor, a liquid phase slurry process reactor, or a liquid phase solution process reactor using a heterogeneous catalyst system, such as a Ziegler-Natta catalyst (Ziegler-Natta catalyst), a homogeneous catalyst system comprising a group 4 transition metal and a ligand structure, such as a metallocene, a non-metallocene center, a heteroaryl, a heterovalent aryloxyether, a phosphinimine, and the like. Combinations of heterogeneous and/or homogeneous catalysts may also be used in a single reactor or dual reactor configuration.

An "ethylene plastomer/elastomer" is a substantially linear or linear ethylene/alpha-olefin copolymer containing a homogeneous short chain branch distribution comprising units derived from ethylene and units derived from at least one C₃-C₁₀Units of an alpha-olefin comonomer. The ethylene plastomer/elastomer has a density of from 0.870g/cc to 0.917 g/cc. Non-limiting examples of ethylene plastomers/elastomers include AFFINITY^TMPlastomers and elastomers (available from Dow Chemical Company), EXACT^TMPlastomers (available from Exxonmobil Chemical), Tafmer^TM(available from Mitsui), Nexlene^TM(available from SK Chemicals Co.) and Lucene^TM(available from LG Chemie Ltd.).

"high density polyethylene" (or "HDPE") is an ethylene homopolymer or has at least one C₄-C₁₀Alpha-olefin comonomer or C₄-C₈An ethylene/α -olefin copolymer of an α -olefin comonomer having a density of 0.940g/cc, or 0.945g/cc, or 0.950g/cc, 0.953g/cc to 0.955g/cc, or 0.960g/cc, or 0.965g/cc, or 0.970g/cc, or 0.975g/cc or 0.980 g/cc. The HDPE can be a monomodal copolymer or a multimodal copolymer. "monomodal ethylene copolymer" is an ethylene/C copolymer having one distinct peak in Gel Permeation Chromatography (GPC) showing molecular weight distribution₄-C₁₀An alpha-olefin copolymer. A "multimodal ethylene copolymer" is an ethylene/C copolymer having at least two distinct peaks in GPC showing a molecular weight distribution₄-C₁₀An alpha-olefin copolymer. Multimodal includes copolymers having two peaks (bimodal) as well as copolymers having more than two peaks. Non-limiting examples of HDPE include DOW^TMHigh Density Polyethylene (HDPE) resin (available from Dow chemical), ELITE^TMReinforced polyethylene resin (available from Dow chemical Co.), CONTINUUM^TMBimodal polyethylene resin (available from Dow chemical Co., Ltd.), LUPOLEN^TM(available from lyondebasell) and HDPE products from Borealis, Ineos and ExxonMobil.

An "interpolymer" is a polymer prepared by polymerizing at least two different monomers. This generic term includes copolymers, which are commonly used to refer to polymers prepared from two different monomers, and polymers prepared from more than two different monomers, such as terpolymers, tetrapolymers, and the like.

"Linear Low Density polyethylene" (or "LLDPE") is linear ethyleneAlpha-olefin copolymer containing a heterogeneous short chain branching distribution comprising units derived from ethylene and units derived from at least one C₃-C₁₀Alpha-olefins or C₄-C₈Units of an alpha-olefin comonomer. LLDPE is characterized by few, if any, long chain branches compared to conventional LDPE. The LLDPE has a density of from 0.910g/cc to less than 0.940 g/cc. Non-limiting examples of LLDPE include TUFLIN^TMLinear low density polyethylene resin (available from Dow chemical Co.), DOWLEX^TMPolyethylene resin (available from Dow chemical) and MARLEX^TMPolyethylene (available from Chevron Phillips).

"Low density polyethylene" (or "LDPE") consisting of an ethylene homopolymer or comprising at least one C₃-C₁₀Alpha-olefins or C₄-C₈An ethylene/alpha-olefin copolymer composition of alpha-olefins having a density of from 0.915g/cc to less than 0.940g/cc and containing long chain branches having a broad MWD. LDPE is usually prepared by means of high pressure free radical polymerization (tubular reactor or autoclave with free radical initiator). Non-limiting examples of LDPE include MarFlex^TM(Chevron Phillips)、LUPOLEN^TM(lyon debasel) and LDPE products from Borealis, Ineos exxonmobil, and others.

"multicomponent ethylene-based copolymer" (or "EPE") comprising units derived from ethylene and units derived from at least one C₃-C₁₀Alpha-olefins or C₄-C₈Units of alpha-olefin comonomers, such as those described in U.S. Pat. No. 6,111,023; USP 5,677,383; and USP6,984,695. The EPE resin has a density of 0.905g/cc to 0.962 g/cc. Non-limiting examples of EPE resins include ELITE^TMReinforced polyethylene (available from Dow chemical Co.), ELITE AT^TMAdvanced technology resins (available from the Dow chemical company), SURPASS^TMPolyethylene (PE) resin (available from Nova Chemicals), and SMART^TM(available from SK chemical Co.).

An "olefin-based polymer" or "polyolefin" is a polymer containing more than 50 weight percent polymerized olefin monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Non-limiting examples of olefin-based polymers include ethylene-based polymers or propylene-based polymers.

A "polymer" is a compound prepared by polymerizing monomers, whether of the same or different type, that in polymerized form provide multiple and/or repeat "units" or "monomer units" that make up the polymer. Thus, the generic term polymer encompasses the term homopolymer, which is commonly used to refer to polymers prepared from only one type of monomer; and the term copolymer, which is commonly used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymers, such as random, block, and the like. The terms "ethylene/a-olefin polymer" and "propylene/a-olefin polymer" indicate copolymers as described above prepared by polymerizing ethylene or propylene, respectively, with one or more additional polymerizable a-olefin monomers. It should be noted that although polymers are often referred to as being "made from" one or more particular monomers, "based on" a particular monomer or monomer type, "containing" a particular monomer content, or the like, in such instances, the term "monomer" should be understood to refer to the polymeric remnants of a particular monomer, and not to unpolymerized species. In general, a polymer herein is referred to as being based on "units" in polymerized form as the corresponding monomer.

The term "propylene-based polymer" is a polymer that contains more than 50 weight percent polymerized propylene monomer (based on the total amount of polymerizable monomers) and optionally may contain at least one comonomer. Propylene-based polymers include propylene homopolymers and propylene copolymers (meaning units derived from propylene and one or more comonomers). The terms "propylene-based polymer" and "polypropylene" are used interchangeably. Non-limiting examples of suitable propylene copolymers include propylene impact copolymers and propylene random copolymers.

"ultra-low density polyethylene" (or "ULDPE") and "very low density polyethylene" (or "VLDPE") are each linear ethylene/alpha-olefin copolymers containing a heterogeneous short chain branch distribution comprising units derived from ethylene and units derived from at least one C₃-C₁₀Units of an alpha-olefin comonomer. ULDPE and VLDPE each have a density of 0.885g/cc to 0.915 g/cc. Non-limiting examples of ULDPE and VLDPE include ATTANE^TMUltra low density polyethylene resin (available from Dow chemical) and FLEXOMER^TMVery low density polyethylene resins (commercially available from the Dow chemical company).

Test method

The D10, D50, and D90 particle sizes were measured using a Coulter LS 230 laser light scattering particle size analyzer, commercially available from Coulter Corporation. The D10 particle size is a particle size in which 10% by mass of the powder consists of particles having a diameter smaller than this value. The D50 particle size is the particle size in which 50% of the mass of the powder consists of particles with a diameter smaller than this value and 50% of the mass consists of particles with a diameter larger than this value. The D90 particle size is a particle size in which 90% of the powder mass is composed of particles having a diameter smaller than this value. The average volume average particle size was measured using a Coulter LS 230 laser light scattering particle size analyzer available from Coulter Corporation. The particle size distribution is calculated according to equation a:

dart impact strength was measured according to ASTM D1709, with results reported in grams (g).

Density is measured according to ASTM D792, method B. The results are reported in grams per cubic centimeter (g/cc).

Differential Scanning Calorimetry (DSC)Differential Scanning Calorimetry (DSC) can be used to measure the melting, crystallization and glass transition behavior of polymers over a wide range of temperatures. This analysis is performed, for example, using a TA Instruments Q1000 DSC equipped with RCS (cryogenic cooling system) and an autosampler. During the test, a nitrogen purge gas flow of 50ml/min was used. Melt extrusion of each sample into a film at about 175 ℃; the molten sample was then allowed to air cool to room temperature (about 25 ℃). From the cooled polymer, 3-10mg of a 6mm diameter sample was extracted, weighed, placed in a lightweight aluminum pan (approximately 50mg), and sealed (crimped shut). Analysis is then performed to determine the thermal properties of the sample.

The thermal behavior of the sample was determined by slowly raising and lowering the sample temperature to establish a heat flow versus temperature profile. First, the sample was rapidly heated to 180 ℃ and held isothermal for 3 minutes in order to remove its thermal history. Subsequently, the sample was cooled to-40 ℃ at a cooling rate of 10 ℃/min and kept isothermal for 3 minutes at-40 ℃. The sample was then heated to 180 ℃ at a 10 ℃/minute heating rate (this is a "second heating" ramp). The cooling and second heating profiles were recorded. The cooling curve was analyzed by setting the baseline endpoint from the start of crystallization to-20 ℃. The heating curve was analyzed by setting the baseline end point from-20 ℃ to the end of melting. The values determined are the extrapolated melting onset point Tm and the extrapolated crystallization onset point Tc. Heat of fusion (H)_f) (in joules/gram) and the calculated% crystallinity of the polyethylene sample using the following equation: % crystallinity ═ H_f) 292J/g). times.100. Determination of the glass transition temperature T from the DSC heating curve in which half of the sample has acquired the heat capacity of the liquid_gSuch as described in Bernhard Wunderlich, Basis of Thermal Analysis in Thermal Characterization of Polymeric Materials (The Basis of Thermal Analysis in Thermal Characterization of Polymeric Materials) 92,278-279(Edith A. Turi eds., second edition 1997). Baselines were drawn from the below and above glass transition regions and extrapolated through the Tg region. The temperature at which the heat capacity of the sample is half way between these base lines is Tg.

The Elmendorf tear (or tear) was measured according to ASTM D1922-15, Machine Direction (MD) and reported in grams force (gf).

Melt flow rate in g/10min was measured according to ASTM D1238(230 ℃/2.16 kg).

Melt Index (MI) in g/10min was measured according to ASTM D1238(190 ℃/2.16kg) (I2).

Form is shown.Polymer morphology (and in particular zinc ionomer/zinc oxide domain size) was determined by microscopy using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM).

A. Sample preparation

OM and SEM-membranes were examined as is and cryo-sectioned on a Leica UC7 microtome equipped with FC7 cryo-section box using a diamond knife at-80 ℃. A section of the membrane with a thickness of about 5 microns was placed on a glass slide containing the immersion oil and covered with a glass cover slip. For SEM inspection, the cold polished film section was placed on an aluminum sample holder and sputtered with an iridium plasma for 20 seconds using an Emitech K575X turbo sputter coater to render the sample conductive for scanning electron microscopy.

B. Technique of

OM-study microscope using Olympus Vanox under transmission Nomarski to capture images from sections. A leica mz-16 stereomicroscope was also used under transmission and reflection illumination. Images were captured using Olympus Stream digital software.

SEM/EDX-FEI Nano600 scanning electron microscope was operated at 10kV accelerating voltage to capture secondary and backscattered electron images (SEI and BEI).

Odor inhibition/odor inhibition valueOdor inhibition is the ability of the composition to neutralize or otherwise reduce the amount of volatile sulfur compounds. In the present disclosure, the odor inhibition of methyl mercaptan was measured according to ASTM D5504-12 using two-dimensional gas chromatography (GC × GC/TOFMS) in conjunction with time-of-flight mass spectrometry. By placing a film formed of DOWLEX 2085G, ethylene/octene LLDPE ontoControl samples were prepared in bags (polyvinyl fluoride). The control was then filled with a known amount of methyl mercaptan in a helium carrier gasBags and closingAnd (4) a bag. Test samples were prepared by placing films formed from the corresponding test compositions, each test film being placed in correspondenceAnd (4) packaging in a bag. Each was then filled with a known amount of methyl mercaptan in a helium carrier gasBags and closingAnd (4) a bag. GC samples were taken from each bag at predetermined time intervals in order to evaluate odor inhibition ability. The odor inhibition value (OSV) of each test sample was calculated by dividing the test sample methyl mercaptan concentration by the LLDPE control methyl mercaptan concentration. The odor inhibition value for each test sample was reported as a percentage of the methionyl alcohol concentration of the control film.

The odor inhibition test was performed as set forth below.

Sample preparation:

1. the film was formed by cutting 1.0g of the film into strips (about 1 cm. times.30 cm).

2. Inserting each membrane into correspondenceIn bags, one film per bag.The bag is SKC 1L sample bag (SKC)Sample bag, 1 liter, catalog No. 232-01).

3. FromThe bag is valved off and the film strip is inserted into the bag through the valve opening using a cotton tipped applicator. The valve was re-mounted to the sample bag, air was forced out of the bag, and the valve was then tightened to seal the bag.

4. Filling with 0.98L helium (AirGas, super helium)And (4) a bag.

5. Charging each with helium using a gas-tight glass syringeThe bag was charged with 20mL of helium gas carrying 1000ppmv methyl mercaptan.

6. At predetermined time intervals from eachThe bag removed a 0.50mL gas sample.

7. Each 0.50mL gas sample was injected into the GC × GC/TOFMS to analyze the methyl mercaptan concentration. Gas chromatography: model Agilent 6890 equipped with a LECO thermal desorption GC x GC modulator and split injection ports, commercially available from Agilent Technologies,2850 centrville Road, Wilmington, DE19808, or an equivalent. A detector: LECO Pegasus time-of-flight mass spectrometer (TOFMS), commercially available from LECOcorporation,3000Lakeview Avenue, Saint Joseph, MI 49085, or equivalent. Chromatography data system: lecochromalto 4D software available from LECO Corporation, or an equivalent. Column: main column: supelco Petrocol DH, 50m × 0.25mm ID, 0.50 μm, secondary column: agilent DB-1701, 1.5m by 0.10mm ID, 0.10 μm film thickness. The secondary column was located in the main GC oven. GC × GC modulation: second dimension separation time: 3 seconds, heat pulse time: 0.40 seconds, cooling time between stages: 1.10 seconds. Modulator temperature offset: 15 ℃ higher than the main oven. Carrier gas: helium, 1.5mL/min using a constant flow corrected by pressure ramping. A sample inlet: restek Siltek deactivation 4.0mm ID Precision Inlet Liner available from Restek is glass Wool (Restek Siltek deactivated 4.0mm ID Precision Inlet Liner w/Wool), catalog #21023-213.5, or equivalent. Split injection mode, split ratio: 30:1, temperature: at 250 ℃ to obtain a mixture.

8. Injection amount: a 0.50mL sample of gas was injected through a gas tight glass syringe. Oven temperature: main GC oven: 40 ℃ for 8 min. And (5) secondary drying oven: off (not used). LECO TOFMS detector: low mass: 20; high quality: 150; and (3) retrieval rate: 100 Hz; detector voltage: 1650 volts; electron energy: -70 volts; quality detection mode: automatic; conveying pipe: 250 ℃; an ion source: 200 ℃; solvent retardation: and 0 minute.

9.Odor inhibition meterCalculating outOdor inhibition ═ concentration gas in sample test bag (sample film) at day X)/(concentration gas in test bag with control film at day X) × 100.

Non-limiting exemplary OSV calculations are provided. On the third day, the peak area of the GC peak area of the methanethiol in the control sample was 119221, while the GC peak area of the sample film was 30566 (both in arbitrary units). The odor inhibition value of the sample was 30566/119221) × 100 ═ 57.8. A calibration curve was generated to correlate the concentration of methyl mercaptan with the GC peak area of methyl mercaptan. Thus, the methyl mercaptan GC peak area or the concentration of methyl mercaptan can be used to calculate an odor inhibition value, where the peak area is compared to the peak area and the concentration is compared to the concentration.

Porosity and surface area.The analysis of the porosity and surface area by Brunauer-Emmett-Teller (BET) was performed using a Micromeritics accelerated surface area and porosimeter (ASAP 2420). Prior to analysis, the samples were outgassed at 105 ℃ and under vacuum.

The ASAP2420 instrument employs a static (volumetric) method of dosing samples and measures the amount of gas that can physically adsorb (physisorb) onto a solid at liquid nitrogen temperatures. For multi-point BET measurements, the nitrogen uptake is measured at a preselected relative pressure point at a constant temperature. The relative pressure is the ratio of the applied nitrogen pressure to the nitrogen vapor pressure at the analytical temperature of 77 kelvin (K). The result of the porosity is in cubic meters per gram or m³The unit is reported as/g. Surface area results in square meters per gram or m²The unit is reported as/g.

Zinc-total amount.The total amount of zinc present in the composition was determined by x-ray fluorescence spectrometry (XRS) according to ASTM D6247. Results are reported in parts per million or ppm.

Drawings

Fig. 1 is a Scanning Electron Microscope (SEM) image of a prior art composition containing polyethylene and zinc oxide particles dispersed therein.

Fig. 2 is an SEM image of a composition containing an olefin-based polymer and an odor inhibitor dispersed therein according to an embodiment of the present disclosure.

Detailed Description

The present disclosure provides a composition. In one embodiment, a composition for suppressing malodor is provided that includes (a)85 wt% to 99 wt% of an olefin-based polymer and (B)15 wt% to 1 wt% of a malodor inhibitor. The odor inhibitor is a blend of particles of (Bi) zinc oxide and (Bii) zinc ionomer. The zinc oxide particles (Bi) have a D50 particle diameter of 100nm to 3000nm, 1m²G to 9m²Surface area of less than 0.020 m/g³Porosity in g. The composition has a methyl mercaptan odor inhibition value of less than 70 when exposed to methyl mercaptan for 3 days as measured according to ASTM D5504-12.

A. Olefin-based polymers

The compositions of the present invention comprise an olefin-based polymer. The olefin-based polymer may be a propylene-based polymer or an ethylene-based polymer. Non-limiting examples of propylene-based polymers include propylene copolymers, propylene homopolymers, and combinations thereof. In one embodiment, the propylene-based polymer is a propylene/α -olefin copolymer. Non-limiting examples of suitable alpha-olefins include C₂And C₄-C₂₀Alpha-olefins, or C₄-C₁₀Alpha-olefins, or C₄-C₈An alpha-olefin. Representative alpha-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene.

In an embodiment, the propylene/α -olefin copolymer is a propylene/ethylene copolymer containing greater than 50 wt% units derived from propylene, or 51 wt%, or 55 wt%, or 60 wt% to 70 wt%, or 80 wt%, or 90 wt%, or 95 wt%, or 99 wt% units derived from propylene, based on the weight of the propylene/ethylene copolymer. The propylene/ethylene copolymer contains a complementary amount (reciprocal amount) of units derived from ethylene, or less than 50 wt%, or 49 wt%, or 45 wt%, or 40 wt% to 30 wt%, or 20 wt%, or 10 wt%, or 5 wt%, or 1 wt%, or 0 wt% of units derived from ethylene, based on the weight of the propylene/ethylene copolymer.

In one embodiment, the olefin-based polymer is an ethylene-based polymer. The ethylene-based polymer may be an ethylene homopolymer or an ethylene/alpha-olefin copolymer.

In one embodiment, the ethylene-based polymer is an ethylene/a-olefin copolymer. Non-limiting examples of suitable alpha-olefins include C₃-C₂₀Alpha-olefins, or C₄-C₁₀Alpha-olefins, or C₄-C₈An alpha-olefin. Representative alpha-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene.

In one embodiment, the ethylene/alpha-olefin copolymer is an LLDPE which is an ethylene/C₄-C₈An alpha-olefin copolymer. LLDPE has one, some or all of the following properties:

(i) a density of 0.910g/cc to 0.930 g/cc; and/or

(ii) Tm of 121 ℃ to 123 ℃; and/or

(iii) A melt index of 0.5g/10min to 1.0g/10 min.

A non-limiting example of a suitable LLDPE is DOWLEX2085, available from the dow chemical company.

B. Odour inhibitors

The compositions of the present invention include an odor inhibitor. The odor inhibitor is a blend of zinc oxide ("ZnO") particles (Bi) and a zinc ionomer (Bii).

B (i) Zinc oxide

The odor inhibitor comprises particles of zinc oxide (or "ZnO"). The ZnO particles have a D50 particle diameter of 100nm to 3000nm, 1m²G to less than 10m²Surface area of less than 0.020 m/g³Porosity in g.

In an embodiment, the ZnO particles have one, some or all of the following properties (i) - (iii):

(i) particle size D50 of 100nm, or 200nm, or 300nm, or 400nm to 500nm, or 600nm, or 700nm, or 800nm, or 900nm, or 1000nm, or 2000nm, or 3000 nm; and/or

(ii)1m²Per g, or 2m²Per g, or 3m²Per g, or 4m²G to 5m²Per g, or 6m²Per g, or 7m²Per g, or 8m²Per g, or 9m²In terms of/gA surface area; and/or

(iii)0.005m³Per g, or 0.006m³In terms of/g, or 0.008m³Per g, or 0.010m³G to 0.012m³Per g, or 0.013m³In terms of/g, or 0.015m³A/g, or less than 0.020m³Porosity in g.

Non-limiting examples of suitable ZnO particles include Zochem 102, Zochem 104 from Zochem inc. and ZnO particles available from US Research Nanoparticles.

B (ii) Zinc ionomer

The odor inhibitor comprises a zinc ionomer. The term "zinc ionomer" (or "ZnI/O") as used herein refers to a copolymer based on zinc salts of a copolymer of ethylene and a vinyl comonomer having acid groups. Non-limiting examples of suitable comonomers having vinyl comonomers with acid groups include methyl/methacrylic acid (methyl/methacrylic acid), vinyl acrylic acid, methacrylate, n-butylacrylic acid, and acrylic acid.

Zinc ionomers are cross-linked polymers in which the bonds are ionic (i.e., interchain ionic bonding) as well as covalent bonds. The zinc ionomer has positively and negatively charged groups that do not associate with each other, thereby providing the zinc ionomer with polar characteristics.

Non-limiting examples of suitable zinc ionomers include zinc salts of ethylene/acrylic acid comonomers, zinc salts of ethylene/methyl-methacrylic acid copolymers, zinc salts of ethylene/vinyl acrylic acid copolymers, zinc salts of ethylene/methacrylate copolymers, zinc salts of ethylene/n-butyl acrylic acid copolymers, and any combination thereof.

In one embodiment, the zinc ionomer is a zinc salt of an ethylene/acrylic acid copolymer. A non-limiting example of a suitable zinc ionomer is AMPLIFY I/O3701 available from the Dow chemical company.

C. Composition comprising a metal oxide and a metal oxide

The composition of the present invention comprises (A)85 to 99 wt% of an olefin-based polymer and (B)15 to 1 wt% of an odor inhibitor. The odor inhibitor is mixed or otherwise blended intoIn an olefin-based polymer matrix. The odor inhibitor is a blend of (Bi) particles of zinc oxide (ZnO) and (Bii) a zinc ionomer (ZnI/O). The zinc oxide particles have a D50 particle size of 100nm to 3000nm, 1m²G to 9m²Surface area of less than 0.020 m/g³Porosity in/g and is referred to hereinafter as composition 1. Composition 1 had a methyl mercaptan odor inhibition value of less than 70 when exposed to methyl mercaptan for 3 days.

The odor inhibitor is present in an amount of 1 wt% to 15 wt% of the composition 1 (based on the total weight of the composition 1) and the ratio of ZnO to ZnI/O (hereinafter "ZnO to ZnI/O ratio") is 3:1 to 1:7, based on the weight of the odor inhibitor. The ratio of ZnO to ZnI/O can be 3:1, or 2:1, or 1:1 to 1:2, or 1:3, or 1:4 or 1:5, or 1:6, or 1: 7.

In one embodiment, the inventive composition comprises 85 wt%, or 90 wt% to 95 wt%, or 97 wt%, or 99 wt% of component (a) which is an ethylene-based polymer. The compositions of the present invention comprise a complementary amount of component (B), or 15 wt%, or 10 wt% to 5 wt%, or 3 wt%, or 1 wt% of an odor inhibitor, wherein the ratio of ZnO to ZnI/O is 1:3, or 1:4, or 1:5 to 1:6, or 1: 7. The zinc oxide particles (Bi) have a D50 particle size of 100nm, or 200nm, or 300nm, or 400nm to 500nm, or 600nm, or 700nm, or 800nm, or 900nm, or 1000nm, or 2000nm, 3000nm, and the zinc oxide particles also have a D50 particle size of 1m²Per g, or 2m²Per g, or 3m²G to 4m²Per g, or 5m²Per g, or 6m²A surface area per gram, and the zinc oxide particles also have a surface area of 0.0050m³In g, or 0.0070m³In terms of/g, or 0.0090m³G to 0.010m³Per g, or 0.013m³G to 0.015m³Porosity in/g and is referred to hereinafter as composition 2. Composition 2 has a methyl mercaptan odor inhibition value of less than or equal to 55 when exposed to methyl mercaptan for 3 days.

In one embodiment, composition 2 contains 1000ppm, or 5000ppm, or 10000ppm, or 20000ppm to 30000ppm, or 40000ppm, or 50000ppm, or 60000ppm, or 90000ppm total zinc. The term "total zinc" as used herein is an aggregate of zinc metal from zinc oxide (Bi) and zinc ionomer (Bii).

In one embodiment, the ethylene-based polymer (a) is present in the composition, and any other polymer is excluded (except ZnI/O in odor suppression). In other words, the ethylene-based polymer is the only polymeric component (the only polymeric component) of the composition other than the zinc ionomer. In another embodiment, the only polymeric component is LLDPE (other than the zinc ionomer).

In one embodiment, total zinc is present in composition 2 and excludes the International Union of Pure and Applied Chemistry (IUPAC) group 5 metals through IUPAC group 12 metals. The term "group 5 metal to group 12 metal" as used herein includes IUPAC group 5 metals (Chemical Abstracts Service [ CAS ] VB), IUPAC group 6 metals (CAS VIB), IUPAC group 7 metals (CAS VIIB), IUPAC group 8 metals (CAS VIIIB), IUPAC group 9 metals (CAS VIIIB), IUPAC group 10 metals (CAS VIIIB), IUPAC group 11 metals (CAS 1B), IUPAC group 12 metals (CAS IIB). It is understood that zinc is a group 12 metal and excludes cadmium and mercury. As used herein, the term "total zinc present and excluding other group 5 to group 12 metals" means that zinc is present and no group 5 to group 12 metals are present in the composition, whereby the composition contains 0ppm, or greater than 0ppm, or 1ppm, or 2ppm to 3ppm of group 5 to group 12 metals.

In an embodiment, composition 2 is a heterogeneous composition and comprises a continuous phase comprised of ethylene-based polymer component (a) and a discontinuous phase of component (B). The discontinuous phase is in the form of discrete regions. The regions are comprised of zinc oxide particles embedded in a zinc ionomer. The regions (zinc ionomer having ZnO particles embedded therein) have an average diameter of 500nm to 1000nm, or 3000nm to 5,000nm, or 7,500nm, or 10,000nm, as measured according to OM/SEM microscopy.

Applicants have found that odour inhibitors having a ZnO to ZnI/O ratio of from 1:3 to 1:7, (i) D50 having a particle size of from 100nm to 3000nm, (ii) a surface area of 1m²G to 6m²(ii) porosity of 0.005m³G to 0.015m³Composition 2 per g of ZnO produced an unexpected improvement in odor suppression. Is regiohomogeneously dispersed inA continuous phase comprised of an ethylene-based polymer.

D. Applications of

The compositions of the present invention are useful in applications where polymeric materials, and in particular olefin-based polymers, are exposed to thiol, H₂S, disulfide, or amine. Non-limiting examples of suitable applications for the compositions of the present invention include trash can liners, poultry diapers, ostomy bags, bed mattresses, mattress covers, poultry packaging, automotive interior parts, carpet fibers, and carpet backings.

In one embodiment, the composition is formed into a film. The film comprises the inventive composition consisting of (a)85 to 99 wt% of an olefin-based polymer and (B)15 to 1 wt% of an odor inhibitor. The odor inhibitor is a blend of (i) particles of zinc oxide and (ii) a zinc ionomer. The zinc oxide particles have a D50 particle size of 100nm to 3000nm, 1m²G to 9m²Surface area of less than 0.020 m/g³Porosity in g. The composition has a methyl mercaptan odor inhibition value of less than 70 at 3 days as measured according to ASTM D5504-12.

In one embodiment, the film is a blown film formed from composition 2, composition 2 having an odor inhibitor value of less than 70 at 3 days, the blown film having

(i) A dart impact strength of 600g or 700g, or 750g to 775g, or 800g, or 825 g; and/or

(ii)300gf, or 350gf, or 375gf to 400gf, or 425 gf.

All other factors being equal, the more ZnO present in the polymeric composition, the higher the odor inhibition capability. The ZnO particle surface area and gaseous odor suppression follow a direct correlation, with the greater the surface area of the ZnO particles, the higher the odor suppression capability. Similarly, ZnO particle porosity and gaseous odor suppression also follow a direct correlation, with the greater the porosity of the ZnO particles, the higher the odor suppression capability.

When present in a polymer matrix, ZnO loading and ZnO particle morphology affect processability and physical properties. High surface area ZnO particles (i.e., surface area of 10 m)²A/g or more than 10m²ZnO particles per gram) tends to increase the viscosity of the matrix polymer in which the ZnO particles are embedded, which can reduce the melt processing of the polymer. The high surface area ZnO particles also inhibit uniform dispersion of the ZnO particles in the polymeric matrix. In addition, large ZnO particles (ZnO particles with an average diameter greater than 3 microns) added to the polymer matrix are known to degrade polymer film properties. Large ZnO particles are problematic and often act as initiation sites for cracks, tears, and crazing within the polymer matrix, reducing physical properties such as tear strength, elongation, and dart hammer impact.

Surprisingly, the inventive compositions (i.e., composition 1 and/or composition 2) exhibited equal or better odor inhibition capability without compromising processability and without compromising film properties. Applicants found that ZnI/O works synergistically with ZnO to improve odor suppression with less total zinc (and less ZnO) compared to ZnO-polymer matrix systems containing more ZnO. ZnI/O alone has little or no odor inhibition. When the surface area of the metal oxide is 1m and D50 is 100nm to 3000nm²G to 9m²A porosity of less than 0.02m³The ability of ZnI/O to synergistically improve odor suppression was unexpected in combination with ZnO particles per gram.

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

Examples of the invention

The materials used in the examples are provided in table 1 below.

TABLE 1

1. Film

By compounding LLDPE, ZnO (when present), ZnI/O (when present) and TiO in a 30mm co-rotating intermeshing Coperion Werner-Pfleiderer ZSK-30(ZSK-30) twin screw extruder₂(when present) the composition of CS1-CS8 and IE1-IE8 was formed into a blown film. The extruder was operated at 40 pounds per hour at a screw speed of 250 rpm. The molding pressure is maintained between 450psi and 500 psi. Maintaining the melt temperature atApproximately 240 ℃. A nitrogen purge was applied at the feed inlet. A standard water bath was used for cooling and a strand cut pelletizer (strand cut pelletizer) was used to produce pellets. The pellets were stored in ambient conditions prior to use.

The blown film is a monolayer film.

TABLE 2 blow film line (blow film line) Process parameters

Parameter(s)	Unit of	No TiO2Film of MB	Containing TiO2Film of MB
				Feed (Takeoff)	m/min	15	15
Flattening	cm	23.5	23.5
				Frosted line	cm	14	14
B.U.R	Ratio of	2.5	2.5
				Die gap	mm	2.0	2.0
Melt temperature-extrusion A	℃	218	218
				Melt temperature-extrusion B	℃	226	226
Melt temperature-extrusion C	℃	215	215
				RPM-extrusion A	rpm	51	51
RPM extrusion part B	rpm	50	50
				RPM-extrusion C	rpm	32	32
Total output	kg/hr	8.8	8.8
				Total thickness of film	mm	0.023	0.056

In the following Table 3, the dart hammer impact and tear strength values are for a film having a thickness of 0.023 mm. Having TiO₂The film of MB had a thickness of 0.056mm, with the exception of CS7 film, which had a thickness of 0.023 mm.

2. Odour suppression

Odor inhibition values were measured according to ASTM D5504-10 in the odor inhibition test method over 192 hours (8 days), as described above.

The film strips (1 cm. times.30 cm and thickness in Table 2) of 1g mass of Control Sample (CS) CS1-CS8 and Inventive Example (IE) IE1-IE8 were placed in a container filled with methyl mercaptan and helium carrier gas as described in the odor inhibition test method disclosed aboveAnd (4) packaging in a bag.

Comparative Samples (CS), CS1-CS8, were prepared. CS1 is a control sample with DOWLEX2085, and CS2 is a control sample 93 wt% LLDPE and 7 wt% TiO₂And (3) master batch.

CS3 and CS4 are blends of ZnO and LLDPE (control), where the amount of ZnO in the blends is different.

CS5, CS6, CS7 were blends of zinc ionomer and LLDPE (control), where the amount of zinc ionomer in the blends was varied.

CS8 is ZnO, TiO₂And LLDPE (control).

IE1-IE8 are inventive examples of inventive compositions consisting of LLDPE and odor inhibitors consisting of ZnO and ZnI/O.

The odor inhibition values (OSV) of CS1-CS8 and IE1-IE8 are provided in Table 3 below.

TABLE 3 methyl mercaptan odor inhibition values and blown film properties

*TiO₂MB-Titania masterbatch, 70 wt% TiO in 30 wt% LLDPE Carrier₂Powder added to obtain white color

n/t-untested

In table 3, CS3-CS4 (ZnO only, 5 wt%) showed that ZnO under only a small load (5 wt%) exhibited only a small degree of odor suppression (OSV 81, 87, respectively) at 3 days.

CS5-CS6 showed that ZnI/O alone had no odor-inhibiting ability (corresponding to OSVs 114, 105 at 3 days).

CS7 shows interaction with TiO₂The blended ZnI/O had only a small odor inhibition capacity (OSV 92 at 3 days).

IE1-IE8 each showed significant odour suppression (IE 1, IE2 were OSV 56, 67, respectively, at 3 days). For example, the ability of IE1 and IE2 to provide odor suppression (OSV: 56, 67, respectively) higher than CS4 (OSV: 87) was unexpected. Without being bound by a particular theory, ZnO acts synergistically with ZnI/O to improve the odor-inhibiting ability of ZnO. It was further unexpectedly found that ZnI/O works synergistically with ZnO to improve odor inhibition, while ZnI/O is an ineffective odor inhibitor alone. Applicants have found that by blending ZnO with ZnI/O, odor suppression is improved compared to increasing the amount of ZnO only in the absence of zinc ionomer.

Figure 1 is an SEM image of CS3(5 wt% ZnO, D50 ═ 300nm) blended in 95 wt% LLDPE (DOWLEX 2085G). Figure 1 shows ZnO particles dispersed in an LLDPE matrix phase. FIG. 2 is an SEM image of IE1 (5 wt% ZnO/5 wt% ZnI/O blended in 90 wt% LLDPE).

The SEM image of fig. 2 shows that ZnI/O is the separate phase from bulk LLDPE, and ZnO particles are encapsulated in the ZnI/O phase to form regions of ZnO embedded in ZnI/O. Without being bound by a particular theory, it is believed that the formation of the ZnI/O-ZnO domains promotes the accelerated diffusion of the odorous molecules. ZnI/O has a strong permeability to polar gases (i.e., sulfur-based gases such as methyl mercaptan). The permeability of ZnI/O facilitates the interaction of odorous gases with ZnO, thereby promoting odor suppression.

The SEM image of fig. 2 shows ZnI/O surrounding and encapsulating ZnO particles. The ZnI/O prevents cavitation at the polymer-particle interface and prevents fragmentation of the bulk polymer. The ZnI/O-ZnO region does not create a start site.

In table 3, films CS1-CS8 each exhibited dart impact strengths less than 700g, while films IE1 and IE2 each exhibited dart impact strengths greater than 700g and greater than 750g (corresponding to dart impact values 810g, 773 g).

Table 3 shows that the physical properties of dart impact strength of IE1 and IE2 are maintained or improved when using the odour inhibitors of the present invention (ZnO and ZnI/O) compared to ZnO only films. In fact, IE1 and IE2 showed improvements in all film properties (dart impact, tear) compared to the unfilled film sample of control film CS 1.

The applicants have surprisingly found that the use of D50 of 100nm to 3000nm and a surface area of 1m²G to 9m²A porosity of less than 0.020m³The inventive odor inhibitor (ZnO-ZnI/O) enables effective odor inhibition with less total zinc while producing blown films with improved dart impact strength (i.e., 600g and greater than 600g or 700g and greater than 700 g). The ability to improve odor suppression with less zinc while maintaining and improving film properties with the inventive compositions and odor inhibitors is unexpected.

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.