WO2024097560A1

WO2024097560A1 - Coated paper and oxygen barrier dispersion

Info

Publication number: WO2024097560A1
Application number: PCT/US2023/077720
Authority: WO
Inventors: David L. Malotky; Brian R. Einsla; Yanxiang Li; Alan M. PIWOWAR
Original assignee: Dow Global Technologies LLC; Rohm and Haas Co
Current assignee: Dow Global Technologies LLC; Rohm and Haas Co
Priority date: 2022-10-31
Filing date: 2023-10-25
Publication date: 2024-05-10
Anticipated expiration: 2025-04-30
Also published as: JP2025535929A; WO2024097561A1; JP2025535627A; CN120129777A; EP4590897A1; KR20250099339A; CN120112691A; KR20250097833A; EP4584436A1

Abstract

The present invention relates to a method of coating a paper with a composition comprising a colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution, an article comprising the coated paper, and a process of making the coated paper. The coated paper is useful as a single layered oxygen barrier coated paper or paperboard. The present invention also relates to a composition comprising a colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution.

Description

DOW DOCKET NO.: 84909-WO-PCT COATED PAPER AND OXYGEN BARRIER DISPERSION The present invention relates to a paper coated with a composition comprising a melt- blended colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution, an article comprising the coated paper, and a process of making the coated paper. The present invention also relates to a composition comprising a colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution. Coating of paper or paperboard for use in a range of applications is known to provide barriers to a wide range of substances including oxygen, water, oil, and acids. Polyvinyl alcohol (PVA) is a water-soluble polymer often used in coating applications to provide beneficial properties such as adhesive and oxygen barrier properties. However, the melting temperature of PVA is high (180^oC or more depending upon hydrolysis level) and requires long mixing times (2 or more hours) at an elevated temperature (90^oC) to dissolve the PVA uniformly into water. Moreover, aqueous solutions of PVA are high in viscosity at low percentage solids (about 10- 15% wt.), especially for higher molecular weight grades of the polymer. Such aqueous PVA solutions are difficult to pump because they do not have the normal shear thinning behavior of a polymer solution. Typically, high performance coatings, such as those used for paper drink cups, are prepared by extrusion coating or lamination of a film directly onto the paper substrate, often with multiple film layers. This layered approach can impart preferential properties to the paper substrate but can also increase processing time, add coating weight, and can negatively impact the recyclability of the paper substrate. International Patent Publication WO 2021/091091 A1 (also published as KR 2021/056129 A1) discloses a barrier resin having a multilayer structure and its manufacturing method. With ethylene vinyl alcohol as one of the representative barrier resins, the barrier resin is provided as an extruded film in a multilayer structure of polyethylene/adhesive resin/ethylene vinyl alcohol layer/adhesive resin/polyethylene. The barrier resin having a multilayer structure is provided as a melt blend resin by adjusting a volume ratio, a viscosity ratio, and the like of a polyolefin, a barrier resin, and a compatibilizer. The barrier resin that is included with the polyolefin and compatibilizer to improve oxygen barrier properties is characterized in that it contains at least one or more selected from the group of polyamide, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer. In this case, the ethylene-vinyl alcohol copolymer contains 10 to 50 mol% of ethylene. When the polyolefin resin continuous phase (matrix) includes a DOW DOCKET NO.: 84909-WO-PCT continuous phase (matrix) or a dispersed phase (domain) of the barrier resin, the volume ratio of the continuous polyolefin resin phase and the barrier resin (volume ratio) values in the range of 30:70 to 70:30 are provided. Preferably, a volume ratio range of 50:50 may be provided. Japanese Patent 3810089 B2 (originating from International Patent Publication WO 1997/022536 A1) discloses a method for producing a laminated packaging material including a core layer and a polyvinyl alcohol layer which is added to one side of the core layer and functions as an oxygen gas barrier layer. Polyvinyl alcohol can be combined with one or more polymers known per se in a simple manner, such as hydrophobic polymers. The mixing ratio of polyvinyl alcohol and hydrophobic polymer is critical, and the amount of hydrophobic polymer is in the range of 5% to 50% of the total weight of the mixture (correspondingly, the amount of polyvinyl alcohol is 95% to 50%), calculated on the total dry weight of the mixture. The present invention provides a process for preparing a single layered oxygen barrier coated paper or paperboard comprising the steps of: a) applying onto paper or paperboard a coating composition comprising a melt-blended colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution; and b) drying the composition to produce a film having a coating weight in the range of 1 to 20 g/m²; wherein the coating composition has a concentration of polymer solids of at least 25 weight percent, a viscosity of less than or equal to 5000 centipoise (cP), and a mean volume (Vmean) particle size in the range of 100 nanometers (nm) to 10 microns; wherein the polyvinyl alcohol of the coating composition is from 10 to less than 40 weight percent based on the total weight of all polymer solids, and is 88% to 98% saponified, with a viscosity (mPa*sec of a 4% aqueous solution at 20^oC) of less than 30 cP; and wherein the thermoplastic particles of the coating composition comprise non-polar thermoplastic polymers having a melt flow index in the range of 5 to 1300 and is from greater than 60 to 90 weight percent based on the total weight of all polymer solids. The present invention further provides an article made according to the process for preparing a single layered oxygen barrier coated paper or paperboard wherein after drying, the coated paper or paperboard has a KIT value of greater than 10 and an oxygen transport rate of less than 20 cc/m²-day. The coating composition, which is a melt-blended colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution, may be prepared by a continuous or batch process. The process for making the coating composition comprises combining the PVA DOW DOCKET NO.: 84909-WO-PCT with water above the melt temperature of the PVA to form a concentrated PVA solution and combining this concentrated PVA solution with a thermoplastic polymer melt to generate a thermoplastic melt emulsion. The concentrated PVA solution and the thermoplastic polymer are mixed at a temperature greater than 15^oC above the glass transition (Tg) or melting temperate (Tm) of the thermoplastic base resin. An example of a preferred continuous process is twin screw extrusion, as described in U.S.8,722,787, Comparative Example E. For a continuous process, the PVA and thermoplastic polymer are advantageously melt compounded together in a continuous process then combined with an amount of water to form the concentrated PVA solution and melt emulsion concurrently in the continuous melt mixing device such as a twin- screw extruder. Alternately, a batch process can be used whereby the combination of PVA with a small amount of water and the melt mixing of this concentrated PVA solution with a thermoplastic polymer can be accomplished successively in a high temperature melt mixing batch process such as a pressurized helical batch mixer. The batch process can be carried out, for example, using a pressurized helical batch mixer such as a 2CV Helicone mixer, which is a conical batch mixer that uses dual intermeshing conical blades to mix high viscosity materials. In the preparation of the coating composition, the concentrated PVA solution can either be made in a separate step (batch pressure mixer process), or more beneficially concurrently with the thermoplastic melt emulsion (continuous extruder process). In both cases the concentrated PVA solution is made by contacting the PVA with water above its melt temperature (greater than 180^oC) and the pressure is sufficient to exceed the steam pressure at the contacting temperature so that water is maintained as a liquid. Additional water is then added to the concentrated thermoplastic melt emulsion to lower the viscosity down to an appropriate level for use as a coating. Although the morphology of a colloidal suspension of thermoplastic particles in an aqueous PVA solution can be created by simple mixing of a thermoplastic polymer dispersion with a PVA solution, the solids content of the inventive composition can be maximized by directly dispersing a thermoplastic polymer into a highly concentrated PVA solution in a melt mixing device, followed by diluting the concentrated thermoplastic melt emulsion to an appropriate percentage solids and viscosity level for use as a coating. The concentration of polymer solids in the coating composition is at least 20 weight percent, preferably at least 25 weight percent, more preferably at least 30 weight percent, and most preferably at least 40 weight percent, based on the weight of water and the polymers combined. The solids content of the coating composition is measured using an infrared solids DOW DOCKET NO.: 84909-WO-PCT analyzer such as an OHAUS® MB45 Moisture Analyzer or similar device. The coating composition has a viscosity of preferably less than or equal to 5000 centipoise (cP), more preferably less than or equal to 2500 cP, and most preferably less than or equal to 1000 cP. The viscosity of the coating composition is measured using an RV viscometer at 50 rpm using the appropriate spindle for the given viscosity, such as an RV3 at 50rpm. A centipoise is one millipascal-second (mPa*s) in SI units. The coating composition has a mean volume (Vmean) particle size preferably in the range of 100 nanometers (nm) to 10 microns, more preferably in the range of 100 nm to 5 microns, and most preferably in the range of 100 nm to 2 microns. All individual values and subranges from 100 nm to 10 microns are included herein and disclosed herein. The particle size of the solids particles of the coating composition is measured using a COULTER^TM LS-230 particle size analyzer (Beckman Coulter Corporation, Fullerton, CA). The polyvinyl alcohol used is 88% to 98% saponified, with viscosity (mPa*sec of a 4% aqueous solution at 20^oC) less than 30, preferably viscosity less than 10. The amount of polyvinyl alcohol in the coating composition by weight percent based on the total weight of all polymer solids, is 10 to less than 40 wt.%, preferably 15-35 wt.%, and most preferably 18-30 wt.%. All individual values and subranges from 10 to less than 40 wt.% are included herein and disclosed herein. Without being bound by any theory, it is theorized that higher levels of PVA provide a rougher surface topography of coated samples, which may result in more surface defects that can lower the OTR performance. Atomic Force Microscopy can help evaluate the roughness of a surface and compare against OTR values, as shown in the examples. Examples of commercially available PVA include Poval™ 4-88 available from Kuraray Co., Ltd.; Poval™ 6- 88, available from Kuraray Co., Ltd.; Poval™ 18-88, available from Kuraray Co., Ltd.; Poval™ 10-98, available from Kuraray Co., Ltd.; Selvol™ E310, available from Sekisui Specialty Chemicals America, and also terminal hydrophobically modified material such as Exceval® RS- 2117, available from Kuraray Co., Ltd.; and blends thereof. Blends of different PVA grades can be used, particularly blends of 88% and 98% hydrolysis polymers. Although disfavored, co- polymers of vinyl alcohols can be included in the PVA, such as ethylene vinyl alcohol (“EVA”). Although EVA polymers may be included with the PVA, it is preferred that no EVA is included, which can also be referred to as being free of added EVA. Where EVA is included with the PVA, the ethylene content of the EVA is preferably less than 10 mole percent, more preferably less than 5 mole percent, and most preferably less than 1 mole percent. An example of a commercially available EVA having an ethylene content of 44 mole percent includes Soarnol™ A4412, and this material does not incorporate well with a thermoplastic polymer. DOW DOCKET NO.: 84909-WO-PCT The thermoplastic particles comprise non-polar thermoplastic polymers, where non-polar is defined as absorbing less than 5 percent (<5%) by weight of water based on the weight of the thermoplastic polymer. The thermoplastic polymer must have a glass transition (Tg) temperature that is less than 30^oC to ensure a flexible, defect free barrier coating. Tg values of the polymers can be calculated herein by using the Fox equation (T.G. Fox, Bull. Am. Physics Soc., Volume 1, Issue No.3, page 123(1956)), that is, for calculating the Tg of a copolymer of monomers M1 and M2, 1/Tg(calc.)= w(M1)/Tg(M1) + w(M2)/Tg(M2), wherein Tg(calc.) is the glass transition temperature calculated for the copolymer, w(M1) is the weight fraction of monomer M1 in the copolymer, w(M2) is the weight fraction of monomer M2 in the copolymer, Tg(M1) is the glass transition temperature of the homopolymer of M1, Tg(M2) is the glass transition temperature of the homopolymer of M2, and all temperatures being in K. The glass transition temperature of homopolymers may be found, for example, in "Polymer Handbook", edited by J. Brandrup and E.H. Immergut, Interscience Publishers. In embodiments where two or more different emulsion polymers or emulsion polymers including multiple phases such as, for example, core/shell polymers are used then the calculated Tg of the emulsion polymer shall be calculated based on the overall composition of the polymeric components. However, if the thermoplastic polymer does not have a low enough Tg, a plasticizer can be added to lower the Tg. The thermoplastic polymer includes olefin polymers and copolymers such as high- density polyethylene (HDPE), ethylene octene copolymer, and ethylene vinyl acetate copolymer; biopolymers such as polyhydroxybutanoate, polylactic acid, and polyacaprolactone; polyesters such as polylactic acid and polyhydroxyalkanoate; thermoplastic acrylics such as isobutylmethacrylate; and combinations thereof. Miscible blends of polymers can also be used as the thermoplastic polymer, such as for example HDPE and polyethylene wax. Preferably the thermoplastic polymer is limited to olefin polymers and copolymers and miscible blends thereof; and most preferably the thermoplastic polymer is limited to olefin polymers and copolymers and blends thereof. The thermoplastic polymer has a melt flow index (MFI) (190^oC/2.16kg) as determined according to ASTM D1238 standard of greater than 5, preferably greater than 25 and most preferably greater than 100, with a maximum MFI of 1300. All individual values and subranges from 5-1300 MFI are included herein and disclosed herein. The amount of thermoplastic polymer in the coating composition by weight percent based on the total weight of DOW DOCKET NO.: 84909-WO-PCT all polymer solids, is from greater than 60 to 90 wt.%, preferably 65-85 wt.%, and most preferably 70-82 wt.%. All individual values and subranges from greater than 60 to 90 wt.% are included herein and disclosed herein. The coating composition may optionally comprise one or more compatibilizers, such as polymeric coupling agents to improve the compatibility between the PVA and thermoplastic particles or any other added components. Preferably though, the coating composition is made without the use of a compatibilizer, which is also referred to as being in the absence of a compatibilizer or being free of any compatibilizer. An example of a suitable coupling agent includes ethylene-co-maleic anhydride, which, when used, is present at a concentration in the range of from 5 weight percent to 20, more preferably to 10 weight percent based on the weight of polymer solids in the coating composition. The coating composition may optionally comprise up to 5 weight percent, based the weight of polymer solids in the composition, of a wax such as ethylene bis(stearamide) and polyolefin waxes such as the commercially available POLYWAX™ 655 polyethylene available from Baker Hughes, Inc. or its affiliates, or ACRAWAX™ C (N,N’ ethylene bisstearamide) available from Lonza or its affiliates. The coating composition may optionally be mixed or formulated with one or more additional components as those skilled in the art can appreciate, such as for example, other water-based dispersions, pigments, wetting agents, defoamers, solvents, rheology modifiers, surfactants, anti-oxidants, and other processing aids to improve barrier and performance attributes of the coated paperboard. Such improvements include for example, compatibility with a substrate, dispersion wet out, coating flexibility, coating integrity upon exposure to extremes in temperature or radiation, flowablity, heat seal, block resistance, and other attributes, as well as to lower cost in use. The coating composition of the present invention allows for repulping of the paper substrate because it is continuous in PVA, and is also low in coat weight, while maintaining a high level of oxygen barrier. The coating composition can be applied to paper or paperboard using traditional wet applications known to those skilled in the art, such as a wire wound drawdown bar. The wet film can then be allowed to dry or heated to remove water, and if heated, preferably to a temperature in the range of from 50 ºC, more preferably from 70 ºC to preferably 150 ºC, more preferably 120 ºC to provide a coat weight of from 1, preferably from 2, more preferably from 4, and most preferably from 6 g/m², to 20, preferably to 15, more preferably to 10, and most preferably to 7 g/m². All individual values and subranges from DOW DOCKET NO.: 84909-WO-PCT 1 to 20 g/m² are included herein and disclosed herein. The paper or paperboard may be uncoated or pre-coated. A very thin layer of a film with high oxygen barrier properties, good oil resistance (KIT values of greater than 10), good heat seal performance, and good block resistance can be coated onto paper or paperboard; moreover, the application can be done in a single pass. The oxygen transport rate (OTR) of coated paper substrates of the present invention is less than 50 cc/m²-day, preferably less than 20 cc/m²-day, and more preferably less than 10 cc/m²-day. Sample Preparation Coated paper samples were prepared by applying coating compositions to an uncoated glossy side of a paper substrate from UPM Specialty Papers having 62 g/m². Coated paper and paperboard samples were prepared by hand using a wire-wound drawdown bar to achieve a dry coat weight of about 10 g/m². Samples were cured in a Fisher Scientific Isotemp 180L Oven FA oven at 100 °C for 2 min. Coat Weight Measurements The coat weight of samples was measured by cutting out 7.17 in² (46.26 cm²) sections coated and uncoated paper, then placing the sections in an oven at 100 °C for 2 min. All the samples were then weighed, and the coat weight was determined by the difference between the coated and uncoated samples. Coat weight is represented as grams per square meter (gsm or g/m²). Kit Testing Coated paper was tested for oil and grease resistance according to TAPPI method T559 cm-12. Prepared Kit solutions, consisting of mixtures of castor oil, toluene, and heptane were applied dropwise to the coated specimens. After 15 seconds, any breakthrough of solvents into the coating was noted, and the solution was wiped from the substrate. Any discoloration or change in appearance to the substrate was considered a failure for that specific Kit solution. A score rating from 1-12 was assigned for the highest numbered Kit solution that passed the test. Number 12 means the best performance. OTR Testing Procedure The oxygen transmission rate (OTR) of the films is measured with an OX-TRAN® Model 2/21 ML module from Mocon Inc. according to ASTM D-3985 at 23^oC, 50% relative humidity, and 1 atmosphere of pressure. Coated paper specimens approximately 30 cm² are cut, then masked and loaded directly in the MOCON OXTRAN® 2/21 ML unit for measurement. The masking material is 3mil aluminum with an acrylic adhesive layer to make the seal. The effective testing DOW DOCKET NO.: 84909-WO-PCT area is 20.27 cm². A test gas containing 100% oxygen is used in order for the permeation to not exceed the detection range of the MOCON OXTRAN® 2/21 ML module. The OTR value is expressed in cc/m²-day or g/m²-day. OTR results have two values, which are replicate test results for the same sample. Block Resistance Test Procedure Block resistance was tested on coated paper samples using a metal spring-loaded compression tool (I.C. block tester, K53000, Koehler Instrument Company, Inc.) at elevated temperature. Samples were cut into 2” x 3” rectangles and placed with coated/coated (reported as C/C) or coated/uncoated (reported as C/U) sides in contact with one another between the metal plates of the compression tool. The spring was compressed at 50 psi, and the entire tool was placed in the oven at 60 ^oC for 1 hour. After removal from the oven, the samples were cooled at room temperature for 30 minutes before testing. Samples were then pulled apart and scored according to the scale described herein. Measurements were completed twice for each sample. The rating score 1 is the best and 5 is the worst. Block resistance ratings 1 – Sheets separate and fall apart with no resistance 2 – Minimal force required to separate sheets 3 – Constant force required to separate sheets 4 – Minimal fiber tear upon separating sheets 5 – Significant fiber tear upon separating sheets, sheets completely adhered together Heat Seal Test Procedure Heat seal was tested on coated paper samples using HST-H3 Instrument. Samples were cut into 1x2 inch strips and loaded with coated/coated (reported as C/C) or coated/uncoated (reported as (C/U) sides in contact with one another between jaws. Pressure 70-80 psi is applied at 190^oC for 0.5 sec. After removal, the samples were cooled at room temperature for about 1 minute (sample is cool to the touch). Samples were then pulled apart and rated P, M, or F with the following meanings. P: passed, paper tears apart when pulled M: marginal, papers peel apart like sticky notes F: failed, papers fall apart Atomic Force Microscopy (AFM) AFM is an analytical technique that enables the imaging of a surface, including polymers, ceramics, composites, glass and biological samples. An AFM is operated in two basic DOW DOCKET NO.: 84909-WO-PCT modes: contact and tapping modes. In contact mode the AFM tip is in continuous contact with the surface. In tapping mode, the AFM cantilever is vibrated above the sample surface and the tip is only in intermittent contact with the surface. The chemical interactions between the sample’s surface atoms and the tip alter the tip’s vibration frequency, allowing the surface atoms to be detected and mapped. AFM provides a 3-D surface profile and can provide surface measurements. For the examples, images were obtained using a Bruker Dimension FastScan™ atomic force microscope in tapping mode. Typical surface imaging parameters were used as shown below and surface attributes were determined, including: average roughness (Sa); Z range – the height difference between the highest and lowest pixels in an image (Sz); max valley depth (Sv); and max peak height (Sp). Post processing of images was performed using SPIP or MountainSPIP image processing software tools. Both height and phase images (viscoelastic differences) were prepared, with the data provided in the examples. The equipment parameters were as shown below. Tip properties: (a) Mode – Tapping; (b) Tip type – TESPA-V2; (c) Spring constant – 48 N/m; (d) Resonance frequency – 190 kHz; (e) Coating – AL 30nm. Scan parameters: (1) Scan rate – 1 Hz; (2) Lines/frame – 512; (3) Free amplitude – 500 mV; (4) Amp/PF Setpoint – 456 mV; (5) Drive frequency – 332 kHz; (6) Drive amplitude – 96 mV; (7) Gains I,P – 1,5. The examples and comparative example(s) utilize the compositions shown in Tables 1 and 2. Table 1 – Polyvinyl Alcohol (PVA) Grades Tradename Supplier Hydrolysis Level Viscosity of 4% solution at 20^oC (mPa*sec)

DOW DOCKET NO.: 84909-WO-PCT Table 2 - Thermoplastic Polymer Base Resins x

EXAMPLES: Inventive coating compositions 1 to 11 and comparative coating compositions 1 to 2 have the polymer phase components and physical properties as shown in Table 3, are formed from the raw materials shown in Tables 1 and 2, and were prepared according to the general procedure, process, and conditions described herein. The thermoplastic polymer resin and PVA listed for each example in Table 3 are fed into a 25 mm diameter twin screw extruder using a controlled rate feeder at the given ratios listed in Table 3 at a total feed rate of 75.6 g/min. Components 1 and 2 are forwarded through the extruder and melted to form a liquid melt material where the melt zone temperature in the extruder is set to be greater than the melting temperature of the PVA material. An initial amount of water is then added into the extruder at a rate roughly equal to the feed rate of the PVA material. In a later section of the extruder additional dilution water is then added at a rate to give the composition percentage solids as indicated in Table 3. The extruder speed used was 600 rpm. At the extruder outlet, a backpressure regulator is used to adjust the pressure inside the extruder barrel to a pressure adapted to reduce steam formation (generally the pressure was from 2 MPa to 4 MPa). Each coating composition exits from the extruder and is filtered first through a 200 micrometer (µm) filter. The resultant filtered coating composition has a solids content measured in weight percent (wt %); and the solids particles of the coating composition has a volume mean particle size measured in microns. The solids content of the coating composition is measured using an infrared solids analyzer, the viscosity of the coating composition is measured using an RV viscometer at 50 rpm using the appropriate spindle for the given viscosity (RV3), and the particle size of the solids particles of the coating composition is measured using a COULTER^TM LS-230 particle size analyzer (Beckman Coulter Corporation, Fullerton, CA). The solids content, viscosity, and the average particle size (PS) of the solids particles of the coating composition are indicated in Table 3. DOW DOCKET NO.: 84909-WO-PCT Table 3 - Coating Compositions

DOW DOCKET NO.: 84909-WO-PCT Table 4 – Coated Paper Samples Tab /C mea ated pap

Table 5 shows AFM determinations for some of the coated paper samples in Table 4. Table 5 – AFM Results Sa Sz Sv Sp Coated Paper Sample [nm] [nm] [nm] [nm] CP Inv 11 95 974 668 306 CP Inv 10 41 543 352 191 In Table 4, composition with 40 wt. t.% PVA.

Claims

DOW DOCKET NO.: 84909-WO-PCT Claims: 1. A process for preparing a single layered oxygen barrier coated paper or paperboard comprising the steps of: a) applying onto paper or paperboard a coating composition comprising a melt-blended colloidal suspension of thermoplastic particles in an aqueous polyvinyl alcohol (PVA) solution; and b) drying the composition to produce a film having a coating weight in the range of 1 to 20 g/m²; wherein the coating composition has a concentration of polymer solids of at least 25 weight percent, a viscosity of less than or equal to 5000 centipoise (cP), and a mean volume (Vmean) particle size in the range of 100 nanometers (nm) to 10 microns; wherein the polyvinyl alcohol of the coating composition is from 10 to less than 40 weight percent based on the total weight of all polymer solids, and is 88% to 98% saponified, with a viscosity (mPa*sec of a 4% aqueous solution at 20^oC) of less than 30 cP; and wherein the thermoplastic particles of the coating composition comprise non-polar thermoplastic polymers having a melt flow index in the range of 5 to 1300 and is from greater than 60 to 90 weight percent based on the total weight of all polymer solids. 2. The process of Claim 1 wherein the PVA of the coating composition is from 15 to 35 weight percent based on the total weight of all polymer solids, and the thermoplastic polymers of the coating composition is from 65 to 85 weight percent based on the total weight of all polymer solids. 3. The process of Claim 1 wherein the thermoplastic polymers are from the group consisting of olefin polymers, olefin copolymers, and miscible blends thereof. 4. The process of Claim 1 wherein the thermoplastic polymers are from the group consisting of high-density polyethylene (HDPE), ethylene octene copolymer, ethylene vinyl acetate copolymer, and blends thereof. 5. The process of Claim 1 wherein the polyvinyl alcohol of the coating composition is free of added ethylene vinyl alcohol. DOW DOCKET NO.: 84909-WO-PCT 6. The process of Claim 1 wherein the coating composition is made without the use of a compatibilizer. 7. The process of Claim 1 wherein the cured film has a coating weight in the range of 6 to 15 g/m². 8. The process of any one of Claims 1-7 wherein the coating composition further comprises up to 5 weight percent of a wax, based on the weight of polymer solids in the coating composition. 9. An article made according to the process of any one of Claims 1-8 wherein after drying, the coated paper or paperboard has a KIT value of greater than 10 and an oxygen transport rate of less than 20 cc/m²-day. 10. An article made according to the process of any one of Claims 1-8 wherein after drying, the coated paper or paperboard has a KIT value of greater than 10 and an oxygen transport rate of less than 10 cc/m²-day.