Patent Description:
Coating of paper or paperboard for use in a range of applications is known to provide barriers to a wide range of substances including water, oil, and acids. Typically, high performance coatings, such as those used for paper drink cups, are prepared by extrusion coating or lamination of a melted polyolefin resin directly onto the paper. This process provides continuous coverage over the substrate and prevents liquid placed into the cup from either contaminating the paper or soaking through completely, thereby causing structural failure of the article.

Liquid applied barrier coatings for paper and paperboard have been described in the art. <CIT> describes an aqueous dispersion of an olefin copolymer that is useful in paper coating applications to improve brightness. <CIT> discloses a dispersible ethylene-(meth)acrylic acid co-polymer for use as a water-repellency layer, requiring separate layers to achieve a broad range of barriers to hydrophobic and hydrophilic materials.

<CIT> discloses a way to prepare a coated paper or paperboard with a relatively thin coating of an omniphobic barrier layer that maintains stain resistance to a wide variety of substances. The dispersion to form the omniphobic barrier layer comprises water, a dispersant, a base polymer, and a neutralizing agent; wherein the dispersant is a copolymer comprising structural units of ethylene and a carboxylic acid monomer; wherein the base polymer comprises structural units of ethylene and a C<NUM>-C<NUM>-alkyl acrylate or methacrylate; wherein the neutralizing agent is ammonia or an organic base having a boiling point of less than <NUM>; and wherein the concentration of the neutralizing agent is sufficient to neutralize at least half of the carboxylic acid groups associated with the dispersant.

Alternative omniphobic barrier layers are needed that do not require ammonia or an organic base as a neutralizing agent and do not require a base polymer to comprise structural units of ethylene and a C<NUM>-C<NUM>-alkyl acrylate or methacrylate. Emissions from ammonia or volatile organic bases are malodorous and can be subject to government regulations and/or have safety issues related to exposure levels.

The present invention provides a process for preparing an omniphobic single layered coating onto paper or paperboard comprising the steps of:.

wherein the neutralizing agent is a hard base and excludes an organic base having a boiling point of less than <NUM>; wherein the concentration of the neutralizing agent is sufficient to neutralize at least half of the carboxylic acid groups present in the dispersion composition.

The present invention further provides an article made according to the process of the present invention.

The composition, which is an aqueous dispersion comprising the dispersant, the base polymer, and the neutralizing agent may be prepared by a continuous or batch process. An example of a preferred continuous process is twin screw extrusion, as described in <CIT>, Comparative Example E. A batch process can be carried out, for example, using a 2CV Helicone mixer, which is a conical batch mixer that uses dual intermeshing conical blades to mix high viscosity materials. The concentration of polymers in the aqueous dispersion is preferably in the range from <NUM>, more preferably from <NUM>, and most preferably from <NUM> weight percent, to preferably <NUM> and more preferably to <NUM> weight percent, based on the weight of water and the polymers combined.

The dispersant is a copolymer with an acid value of less than <NUM>, comprising structural units of ethylene and a carboxylic acid monomer, such as methacrylic acid, or itaconic acid. Preferably the dispersant is a copolymer comprising structural units of ethylene and methacrylic acid (EMAA). The dispersant has an acid value of less than <NUM>. Most preferably the dispersant is EMAA with an acid value of <NUM>-<NUM>. The term "acid value" refers to the mass of potassium hydroxide (KOH) in milligrams that is required to neutralize one gram of copolymer and is determined by ASTM (D974). The term "structural unit" of the named monomer refers to the remnant of the monomer after polymerization. For example, a structural unit of methacrylic acid is as illustrated:
<CHM>
structural unit of methacrylic acid
where the dotted lines represent the points of attachment of the structural unit to the polymer backbone.

The dispersant copolymer has a melt flow index in the range of from <NUM> to <NUM>/<NUM> at <NUM>/<NUM> (according to ASTM D1238) and the weight-to-weight ratio of structural units of ethylene to carboxylic acid monomer is in the range of from <NUM>:<NUM> , preferably from <NUM>:<NUM>, and more preferably from <NUM>:<NUM> weight percent; to <NUM>:<NUM>, and preferably to <NUM>:<NUM> weight percent, based on the weight of the dispersant copolymer. The concentration of the dispersant is in the range of from <NUM> to <NUM> weight percent, preferably from <NUM> weight percent, more preferably from <NUM> weight percent, more preferably from <NUM> weight percent, preferably to <NUM>, more preferably to <NUM> weight percent, based on the weight of polymer solids in the dispersion; provided that the concentration of the dispersant in the composition is sufficient to yield a cured film with a Cobb value of less than <NUM>/m<NUM>, preferably less than <NUM>/m<NUM> and more preferably less than <NUM>/m<NUM> and oil contamination of less than <NUM> percent, preferably less than <NUM> percent, more preferably less than <NUM> percent, most preferably <NUM> percent. Most preferably the concentration of the dispersant in the composition is in the range of from <NUM> to <NUM> weight percent, based on the weight of polymer solids in the dispersion; provided that the concentration of the dispersant in the composition is sufficient to form a cured film with a Cobb value as described. The concentration of the dispersant in the composition depends on the acid value of the dispersant, so that higher acid value dispersants require a lower concentration than lower acid value dispersants. When the dispersant has an acid value of <NUM>, the concentration of the dispersant in the composition is preferably up to <NUM> weight percent, based on the weight of polymer solids in the dispersion. A suitable commercially available dispersant includes NUCREL™ <NUM> (an EMAA copolymer with an acid value of <NUM>).

The base polymer comprises non-functionalized ethylene-co-alkene copolymers, wherein the weight-to-weight ratio of the structural units of ethylene to alkene is in the range of from <NUM>:<NUM>, preferably from <NUM>:<NUM>; and more preferably from <NUM>:<NUM>; to <NUM>:<NUM>, more preferably to <NUM>:<NUM>; and most preferably to <NUM>:<NUM>. Preferred base polymers include ethylene-co-octene, ethylene-co-hexene, ethylene-co-butene copolymers, or mixtures thereof. Optionally the base polymer can also include functionalized ethylene copolymer comprising structural units of a C<NUM>-C<NUM>-alkyl acrylate or methacrylate; though preferably the base polymer has no functionalized ethylene copolymer comprising structural units of a C<NUM>-C<NUM>-alkyl acrylate or methacrylate.

The concentration of base polymer in the composition is sufficient to form a cured film with a Cobb value of less than <NUM>/m<NUM>, preferably less than <NUM>/m<NUM> and more preferably less than <NUM>/m<NUM> and oil contamination of less than <NUM> percent, preferably less than <NUM> percent, more preferably less than <NUM> percent, most preferably <NUM> percent. Preferably, the concentration of the base polymer is preferably in the range of from <NUM>, more preferably from <NUM>, to <NUM>, more preferably to <NUM>, and most preferably to <NUM> weight percent, based on the weight of polymer solids in the dispersion. A preferred range is <NUM> to <NUM> percent based on the weight of polymer solids in the dispersion. Commercial examples of base polymers include: ENGAGE™ <NUM> (an ethylene octene copolymer having a melt index (<NUM>/<NUM>) of <NUM>/<NUM> per ASTM D1238), ENGAGE™ <NUM> (an ethylene octene copolymer having a melt index (<NUM>/<NUM>) of <NUM>/<NUM> per ASTM D1238), AMPLIFY™ EA103 (a poly(ethylene-co-ethyl acrylate) copolymer with <NUM>% ethyl acrylate and a melt index (<NUM>/<NUM>) of <NUM>/<NUM> per ASTM D1238), AFFINITY™ EG8200G (an ethylene octene copolymer having a melt index (<NUM>/<NUM>) of <NUM>/lOmin per ASTM D1238); all available from Dow, Inc. or its affiliates.

The neutralizing agent is a hard base, such as potassium hydroxide (KOH), sodium hydroxide (NaOH) and/or lithium hydroxide (LiOH) and excludes an organic base having a boiling point of less than <NUM>, such as ammonia or an amine, N,N-dimethylethanolamine (DMEA), diethylamine, and morpholine. The concentration of neutralizing agent is sufficiently high to neutralize at least half of the carboxylic acid groups present in the dispersion composition. For example, if the dispersion composition comprises <NUM> mol of carboxylic acid groups in a given mass, at least <NUM> mol of a hard base such as KOH would be required. Thus, the molar ratio of basic functionality in the neutralizing agent to carboxylic acid groups in the dispersion composition is at least <NUM>:<NUM>. Preferably the ratio is in the range of from <NUM>:<NUM>, more preferably from <NUM>:<NUM>, to <NUM>:<NUM>, to preferably <NUM>:<NUM>, and more preferably to <NUM>:<NUM>.

The composition may optionally comprise other components including polymeric coupling agents to improve the compatibility between the dispersant and the base polymer. 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 <NUM> weight percent to <NUM>, more preferably to <NUM> weight percent based on the weight of polymer solids in the dispersion. A commercial example of a coupling agent includes: LICOCENE™ <NUM> stabilized maleic anhydride grafted polyethylene wax (sometimes referred to as MA-g-PE), available from Clariant Corporation or its affiliates. It is expected that the amount of neutralizing agent will be adjusted based on the total acid of the dispersion composition when additional components are added.

The composition may optionally comprise up to <NUM> weight percent, based the weight of polymer solids in the dispersion, of a wax such as ethylene bis(stearamide) and polyolefin waxes such as the commercially available POLYWAX™ <NUM> polyethylene available from Baker Hughes, Inc. or its affiliates, or ACRAWAX™ C (N,N' ethylene bisstearamide) available from Lonza or its affiliates.

The 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, and other attributes, as well as to lower cost in use.

The 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 heated to remove water, preferably to a temperature in the range of from <NUM>, more preferably from <NUM> to preferably <NUM>, more preferably <NUM> to provide a coat weight of from <NUM>, preferably from <NUM>, more preferably from <NUM>, and most preferably from <NUM>/m<NUM>, to <NUM>, preferably to <NUM>, more preferably to <NUM>, and most preferably <NUM>/m<NUM>. The paper or paperboard may be uncoated or pre-coated.

A very thin layer of a film with low water uptake and high oil resistance (an omniphobic film) can be coated onto paper or paperboard; moreover, the application can be done in a single pass because the omniphobic properties are present in base polymer and the dispersant in the applied aqueous composition. It has been surprisingly discovered that use of a hard base in combination with a copolymer dispersant having an acid value of less than <NUM>, particularly an EMAA copolymer dispersant, provides a polyolefin dispersion composition with excellent water and oil barrier properties when applied and cured on paper and paperboard without requiring the use of undesirable low boiling point neutralizing agents. Additionally, such compositions do not necessarily require functionalized ethylene copolymer comprising structural units of a C<NUM>-C<NUM>-alkyl acrylate or methacrylate to provide coatings with oil/grease resistance and has no observed adhesion issues to pre-coated paper and board.

Coating formulations were prepared by applying polyolefin dispersion compositions to an uncoated substrate. The substrate was <NUM>/m<NUM> uncoated solid bleached sulphate (SBS) paperboard. Coatings of paper and paperboard samples were prepared by hand using either a #<NUM>, #<NUM>, or #<NUM> wire-wound drawdown bar. Samples were cured in a Fisher Scientific Isotemp <NUM> Oven FA oven at <NUM> for <NUM>.

The coat weight of samples was measured by cutting out <NUM> in<NUM> (<NUM><NUM>) sections coated and uncoated paper, then placing the sections in an oven at <NUM> for <NUM>. All the samples were then weighed and the coat weight was determined by the difference between the coated and uncoated samples.

Water uptake testing was performed in a modified version of TAPPI method T441 "Water absorptiveness of sized (non-bilious) paper, paperboard, and corrugated fiberboard (Cobb test). " Samples of coated paper or paperboard were prepared using the above method and then cut into <NUM>-cm<NUM> round samples using a circular die and pneumatic press. A round sample was placed in an oven at <NUM> for <NUM>, then removed and weighed, then placed on a rubber mat; a circular metal ring was affixed on top of the round sample and clamped to prevent water leakage. Water at <NUM> was then poured over the sample to a height of <NUM> (<NUM> of test liquid) and allowed to stand for <NUM>. At the end of the test period, the test liquid was poured off and the coated sample was placed between two sheets of blotter paper. A <NUM>-kg metal roller was passed over the sample twice. Finally, the sample was weighed and the water uptake was calculated based on the difference in mass between the exposed and unexposed sample. Cobb values are reported in units of g/m2. Cobb values of up to <NUM>/m2 are reported as passing the test.

Oil and grease resistance of coatings was performed using a modified Ralston Purina <NUM> test method. The coated paper or paperboard was cut into a <NUM>" x <NUM>" square test sample and weighed. The test sample was placed on a sheet of standard graph paper with a ¼" grid, which paper was fixed on a metal sheet. Two <NUM>" cotton flannel rounds saturated with vegetable oil were placed in the center of the coated paper or paperboard. The rounds were held in place by a brass weight with a diameter and a length of <NUM> inch. Samples of coated paper and paperboard cut to the same dimensions were also placed on the metal sheet to measure water loss by the paper substrate during subsequent heat aging. The samples were heat-aged in an oven at <NUM> for <NUM>, after which time the samples were allowed to cool to room temperature. The weight and the cotton rounds were removed and excess oil was blotted off with a paper towel. Finally, the samples were weighed and the oil uptake (in g/m<NUM>) was calculated based on mass difference correcting for water loss; the graph paper was examined to determine the percentage of the squares contaminated by oil break-through (referred to in the Table as "OGR % contamination"). Oil contamination values of less than <NUM> percent are reported as passing the test.

The examples and comparative example(s) utilize the following compositions: NUCREL™ <NUM> (an EMAA copolymer with an acid value of <NUM> and melt index of <NUM>/<NUM> @ <NUM>/<NUM> per ASTM D1238), available from Dow, Inc. or its affiliates; experimental EMAA copolymer A-<NUM> (an EMAA copolymer with an acid value of <NUM> and melt index of <NUM>/<NUM> @ <NUM>/<NUM> per ASTM D1238); experimental EMAA copolymer B-X74 (an EMAA copolymer with an acid value of <NUM> and melt index of <NUM>/<NUM> @ <NUM>/<NUM> per ASTM D1238); PRIMACOR™ 5980i copolymer (an ethylene acrylic acid copolymer (<NUM> wt % acrylic acid), which has a melt index of <NUM>/<NUM> minute per ASTM Method D1238 at <NUM>/<NUM>), available from SK Global Chemical Co. or its affiliates. AFFINITY EG™ <NUM> (an ethylene octene copolymer having a melt index (<NUM>/<NUM>) of <NUM>/lOmin per ASTM D1238), ENGAGE™ <NUM> (an ethylene octene copolymer having a melt index (<NUM>/<NUM>) of <NUM>/lOmin per ASTM D1238), AMPLIFY™ EA103 (a poly(ethylene-co-ethyl acrylate) copolymer with <NUM>% ethyl acrylate and a melt index (<NUM>/<NUM>) of <NUM>/<NUM> per ASTM D1238); all available from Dow, Inc. or its affiliates; potassium hydroxide (KOH) and dimethylethanolamine (DMEA); LICOCENE™ <NUM> stabilized maleic anhydride grafted polyethylene wax (sometimes referred to as MA-g-PE), available from Clariant Corporation or its affiliates; and ACRAWAX™ C (N,N' ethylene bisstearamide) available from Lonza or its affiliates. Experimental EMAA copolymers A and B may be prepared by standard free-radical copolymerization methods, using high pressure, operating in a continuous manner. Monomers are fed into the reaction mixture in a proportion which relates to the monomer's reactivity, and the amount desired to be incorporated. In this way, uniform, near-random distribution of monomer units along the chain is achieved. Polymerization in this manner is well known and is described for example, in <CIT>).

Amplify™ EA103 (<NUM> weight percent of polymer solids), Nucrel™ <NUM> (<NUM> weight percent of polymer solids), MA-g-PE (<NUM> weight percent of polymer solids), Acrawax™ C (<NUM> weight percent of polymer solids) and Engage™ <NUM> (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Bersdorff™ ZE25 UTX extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added and the mixture was cooled to <NUM>° C at the extruder outlet. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was cooled and filtered through a <NUM>-µm filter and deemed good quality based on low grit retention (< <NUM> ppm), colloidal stability (no phase separation with <NUM> hours of production), dispersion solids (close to percent solids added to extruder) and particle size ( < <NUM>, as determined using a Coulter LS320 particle size analyzer or comparable tool)).

ENGAGE™ <NUM> (<NUM> weight percent of polymer solids) and experimental copolymer B-X74 (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Bersdorff™ ZE25 UTX extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was cooled and filtered through a <NUM>-µm filter.

Example <NUM> utilizes the procedure of Example <NUM>, but without Amplify™ EA103 and with the components as shown in Table <NUM>. Examples <NUM>-<NUM> utilize the procedure of Example <NUM> with the components as shown in Table <NUM>.

AFFINITY™ EG8200G (<NUM> weight percent of polymer solids) and NUCREL™ <NUM> (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Coperion™ ZSK extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added and the mixture was cooled to <NUM> at the extruder outlet. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was then further cooled to <NUM> through an in line cooler.

AFFINITY™ EG8200G (<NUM> weight percent of polymer solids) and experimental copolymer A (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Bersdorff™ ZE25 UTX extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was cooled and filtered through a <NUM>-µm filter.

Examples <NUM>-<NUM> utilize the procedure of Example <NUM> with the components as shown in Table <NUM>. Example <NUM> - Preparation of an Aqueous Dispersion of Amplify™ EA103 Base Polymer, Dispersant, Polymeric Coupling Agent, Wax and Engage™ <NUM> Base Polymer at a <NUM>:<NUM>:<NUM>:<NUM>:<NUM> w/w/w/w/w Ratio EA103 (<NUM> weight percent of polymer solids), PRIMACOR™ 5980i (<NUM> weight percent of polymer solids), MA-g-PE (<NUM> weight percent of polymer solids), Acrawax™ C (<NUM> weight percent of polymer solids) and <NUM> (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Bersdorff™ ZE25 UTX extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added and the mixture was cooled to <NUM>° C at the extruder outlet. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was cooled and filtered through a <NUM>-µm filter.

Examples <NUM>-<NUM> utilize the procedure of Example <NUM> with the components as shown in Table <NUM>.

AFFINITY™ EG8200 (<NUM> weight percent of polymer solids) and PRIMACOR™ <NUM> (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Coperion™ ZSK extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% KOH (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added and the mixture was cooled to <NUM>° C at the extruder outlet. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was then further cooled to 37C through an in line cooler.

Amplify™ EA103 (<NUM> weight percent of polymer solids), Nucrel™ <NUM> (<NUM> weight percent of polymer solids), MA-g-PE (<NUM> weight percent of polymer solids), Acrawax™ C (<NUM> weight percent of polymer solids) and Engage™ <NUM> (<NUM> weight percent of polymer solids) were fed individually and concurrently from separate hoppers at the specified relative weights at a rate of <NUM> Ibs/h (<NUM>/h) into a <NUM> Bersdorff™ ZE25 UTX extruder with <NUM> LID (rotating at <NUM> rpm). The extruder temperature profile was ramped to <NUM> prior to the introduction, through ISCO pumps, of water (<NUM>/min at <NUM> and <NUM> psi) and <NUM> wt% DMEA (<NUM>/min) separately and concurrently. Dilution water (<NUM>/min at <NUM> and <NUM> psi) was then added. A back-pressure regulator was used at the extruder outlet to adjust the pressure in the extruder barrel to reduce steam formation. The resulting dispersion was cooled and filtered through a <NUM>-µm filter. This filtration operation proceeded much more slowly than the other examples, and <NUM>% of the added solids was removed during the filtration. Both of these results are indicative of a very poor quality dispersion. The quality of all previous dispersion examples could be described as good.

Example <NUM> utilizes the procedure of Example <NUM> with the components as shown in Table <NUM>. As with Example <NUM>, filtration proceeded very slowly, but there was no corresponding removal of large amounts of polymer solids. This dispersion was considered poor in quality due to high levels of grit (> <NUM> ppm), dispersion solids (<NUM> % lower than solids added to extruder) and particle size (> <NUM>).

Table <NUM> illustrates a summary of the sample compositions.

All samples were cured at <NUM> for <NUM>. All Cobb data was generated at <NUM> water for <NUM>. The target Cobb value for water uptake was <<NUM>/m<NUM>. The target value for oil uptake was <<NUM>/m<NUM> and the target value for contamination was <NUM>%. Table <NUM> illustrates the coat weights, Cobb values, oil uptake values and contamination percentage results for all the samples.

Claim 1:
A process for preparing an omniphobic single layered coating onto paper or paperboard comprising the steps of:
a) applying onto paper or paperboard a dispersion composition comprising water, a dispersant, a base polymer, and a neutralizing agent; and
b) heating the composition to produce a cured film having a thickness in the range of <NUM> to <NUM>/m<NUM>;
wherein the sum of the dispersant and the base polymer comprise from <NUM> to <NUM> percent of the weight of polymer solids in the dispersion; wherein
the dispersant is a copolymer with an acid value of less than <NUM>, comprising structural units of ethylene and a carboxylic acid monomer, wherein the copolymer has a melt flow index in the range of from <NUM> to <NUM>/<NUM> at <NUM>/<NUM>; wherein the weight-to-weight ratio of structural units of ethylene to carboxylic acid monomer is in the range of from <NUM>:<NUM> to <NUM>:<NUM>; and wherein the dispersant has a concentration in the range of from <NUM> to <NUM> weight percent based on the weight of polymer solids in the dispersion, provided that the concentration of the dispersant in the composition is sufficient to form a cured film with a Cobb value of less than <NUM>/m<NUM> and oil contamination of less than <NUM> percent;
the base polymer comprises non-functionalized ethylene-co-alkene copolymers, wherein the weight-to-weight ratio of the structural units of ethylene to alkene is in the range of from <NUM>:<NUM> to <NUM>:<NUM>; and
wherein the neutralizing agent is a hard base and excludes an organic base having a boiling point of less than <NUM>; wherein the concentration of the neutralizing agent is sufficient to neutralize at least half of the carboxylic acid groups present in the dispersion composition.