PIGMENTED SIZE PRESS AND SURFACE SIZE FOR COATED PAPER AND PAPERBOARD

A size press composition for paper or paperboard is provided, which includes: binder; pigment; synthetic surface sizing agent; and water; wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

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Description
BACKGROUND

The present inventor has observed that in papermaking, one normally sees a lot of dewatering of the coating at the first coating station. This is more pronounced as the paper/paperboard basis weight increases, as more fibers are available to absorb the water out of the coating. This can cause loss of coating binder into the sheet with the water, so that higher latex levels are required to compensate for this loss. This can also cause premature immobilization of the coating solids, which makes it difficult to control the coatweight at the blade coater. The dewatering also limits the solids content of the coating that can be used. The inventor has found that it is possible to increase the solids content of the coatings used at both coating heads. Increased solids content of the coatings means that less water is present for a given coatweight, so higher machine speeds are possible if the machine speed is limited by drying capability of the paper machine. Paperboard can also be rougher than a lightweight paper, especially as the thickness of the paperboard increases.

Synthetic surface sizing agents, such as styrene acrylic emulsions (SAE), ScripSet™ styrene maleic anhydride (SMA), or alkyl ketene dimer (AKD) are commonly used to improve printability of the paper surface. These synthetic surface sizing agents can improve toner adhesion for electrophotographic printing, and reduce ink bleed for ink jet and flexographic printing.

Starch/GCC mixtures have been used at the size press to make pigmented paper for premium ink jet and laser paper. These papers are uncoated, and are not subsequently coated, but are pigmented at the size press as a replacement for coated paper.

The inventor has found that it is possible to modify the size press formulation to create a water barrier layer to decrease or prevent the dewatering of the coating, and also to fill in the pores at the paper surface. The inventor has found that, surprisingly, both of these will help keep the coating pigments and binder, for example a latex binder, at the paper surface. This will also make the sheet smoother so that less coating is needed to attain a given smoothness.

BRIEF DESCRIPTION OF THE SEVERAL EMBODIMENTS

One embodiment provides a size press composition for paper or paperboard, comprising:

binder;

pigment;

synthetic surface sizing agent; and

water;

wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and

wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

Another embodiment provides a sized web, for paper or paperboard, comprising:

a dried web comprising cellulosic fibers; and

the size press composition on one or both sides of the dried web.

Another embodiment provides a coated or uncoated paper or paperboard, comprising the sized web.

Another embodiment provides a paper or paperboard, comprising:

a sized web, comprising:

    • a dried web comprising cellulosic fibers; and
    • a size press composition on one or both sides of the dried web, the size press composition comprising:
      • binder;
      • pigment;
      • synthetic surface sizing agent; and
      • substantially no water;

wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and

wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

Another embodiment provides an article, comprising the paper or paperboard.

Another embodiment provides a method, comprising contacting, on a papermaking machine:

a dried web comprising cellulosic fibers; and

the size press composition;

to form a sized web.

DETAILED DESCRIPTION OF THE SEVERAL EMBODIMENTS

In one embodiment, a size press composition for paper or paperboard is provided, which includes:

binder;

pigment;

synthetic surface sizing agent; and

water;

wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and

wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

In embodiments herein, the size press composition may be in the form of an aqueous solution, slurry, emulsion, dispersion, suspension, mixture, thixotropic composition, or colloidal composition.

In embodiments herein, the binder may include one or more of natural product, casein, soy protein, fatty acid salts and copolymers, water soluble polymer, water soluble starch co-binder, polyvinyl alcohol, poly acrylic acid, poly acrylic acid salt, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polymer emulsion, acrylate, styrene acrylate, styrene butadiene, styrene acrylonitrile, polyurethane, polyvinyl acetate, polyethylene emulsion, polyethylene (PE) polymers; polyethylene terephthalate (PET) polymers; polyhydroxyalkanoate (PHA) polymers; polylactic acid (PLA) polymers; polyglycolic acid (PGA) polymers; polyvinyl acetate polymers; waxes; polyurethane polymers; or epoxy resins, starch, high-amylose corn starch, waxy corn starch, tapioca starch, cationic starch, ethylated starch, oxidized starch, corn starch, potato starch, rice starch, dent corn starch, waxy starch, modified starch, FilmKote™ by Ingredion, FilmKote 370™ by Ingredion (modified starch), Aquabloc™ by Aquasol, Aquabloc 403™ by Aquasol (starch), Flex Starch™ by Tate and Lyle, Clear-Cote 640™ by Tate and Lyle (waxy starch), PG270™ by Ingredion (ethylated starch), RAP 810™ by Trinseo (styrene acrylate), XU 31669 SB™ latex by Trinseo (styrene butadiene), XU 31695™ by Trinseo (styrene acrylonitrile), Polyco 3960™ by Dow (poly vinyl acetate), Polyco 2160 IPA™ by Dow (poly vinyl acetate), binder, Hypod 1001™ by Dow (polyethylene emulsion), Hypod 9105™ by Dow (polyethylene emulsion), or a combination thereof.

In embodiments herein, the binder may include one or more natural products such as casein, soy protein, and fatty acid salts and copolymers, water soluble polymers such as polyvinyl alcohol, poly acrylic acid and salts, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, etc, and polymer emulsions such as acrylates, styrene acrylates, styrene butadienes, polyurethanes, polyvinyl acetates, polyethylene (PE) polymers; polyethylene terephthalate (PET) polymers; polyhydroxyalkanoate (PHA) polymers; polylactic acid (PLA) polymers; polyglycolic acid (PGA) polymers; polyvinyl acetate polymers; waxes; polyurethane polymers; or epoxy resins, and their copolymers and derivatives. Any combination thereof may be suitably used.

In embodiments herein, the binder may include a starch selected from the group including high-amylose corn starch, waxy corn starch, tapioca starch, cationic starch, ethylated starch, oxidized starch, corn starch, potato starch, rice starch, dent corn starch, waxy starch, modified starch, FilmKote™ by Ingredion, FilmKote 370™ by Ingredion (modified starch), Aquabloc™ by Aquasol, Aquabloc 403™ by Aquasol (starch), Flex Starch™ by Tate and Lyle, Clear-Cote 640™ by Tate and Lyle (waxy starch), PG270™ by Ingredion (ethylated starch), and a combination thereof.

In embodiments herein, the binder may include a water-soluble polymer binder selected from the group including starch binders, cellulosic binders, polyvinyl alcohol binders, polyacrylic acid binders, polymethacrylic acid binders, polyvinylamine binders, polyacrylamide binders, polyether binders, sulfonated polystyrene binders, carboxylated polystyrene binders, and a combination thereof.

In embodiments herein, the water-soluble polymer binder may be a starch binder.

In embodiments herein, the binder may include a polymer latex binder selected from the group including styrene butadiene rubber latexes, acrylic polymer latexes, polyvinyl acetate latexes, styrene acrylic copolymer latexes, polyurethane latexes, starch/acrylic copolymer latexes, starch/styrene acrylic copolymer latexes, polyvinyl alcohol (PVOH)/styrene acrylic copolymer latexes, PVOH/acrylic copolymer latexes, and a combination thereof.

In embodiments herein, the polymer latex binder may be a styrene-acrylic latex binder.

In embodiments herein, the binder may be ethylated starch.

In embodiments herein, any combination of binder may be suitably used.

In embodiments herein, the pigment may be selected from the group including ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), clay, kaolin clay, talc, mica, calcium sulfate, absorbent plastic pigment particles, calcined clay pigment particles, titanium dioxide pigment particles, barium sulfate pigment particles, silica pigment particles, zeolite pigment particles, fumed silica pigment particles, alumina pigment particles, bentonite clay pigment particles, HC (Hydrocarb) 90™ by Omya (ground calcium carbonate), HC (Hydrocarb) 60™ by Omya (ground calcium carbonate), Hydrafine 90W™ by KaMin (clay), and a mixture thereof.

In embodiments herein, the pigment may be ground calcium carbonate (GCC).

In embodiments herein, any combination of pigment may be suitably used.

In embodiments herein, the pigment may be finely divided, e.g., having a size range of from about 0.5 to about 5 microns. This range includes all values and subranges therebetween, including about 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, and 5 microns.

In embodiments herein, the synthetic surface sizing agent generally refers to a non-starch surface sizing agent. The synthetic surface sizing agent is not particularly limited and may be selected from the group including styrene maleic anhydride (SMA), alkyl ketene dimer (AKD), AKD (IP Size 2000)™ by Solenis (alkyl ketene dimer), Scripset 745™ by Solenis (styrene maleic anhydride), styrene acrylic emulsion (SAE), polymer emulsions with a surface energy of 50 dynes or less after drying, and a combination thereof.

In embodiments herein, the synthetic surface sizing agent may be styrene maleic anhydride (SMA).

In embodiments herein, the synthetic surface sizing agent may be Scripset™.

In embodiments herein, any combination of synthetic surface sizing agent may be suitably used.

In embodiments herein, the size press composition may further include one or more water soluble salt.

In embodiments herein, the water soluble salt may be one or more of a multivalent cationic metal salt, an inorganic salt, an organic salt, or a combination thereof.

In embodiments herein, the water soluble salt may be one or more multivalent cationic metal salt, inorganic salt, organic salt, or combination thereof selected from the group including calcium chloride, calcium acetate, calcium magnesium acetate, calcium nitrate, calcium hydroxide, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium sulfate, aluminum chloride, aluminum nitrate, aluminum chlorohydrate, aluminum sulfate, sodium aluminum sulfate, vanadium chloride, and a combination thereof.

In embodiments herein, the water soluble salt may be calcium chloride.

In embodiments herein, the water soluble salt may be a metal drying salt, multivalent metal drying salt, monovalent metal drying salt, or a combination thereof.

In embodiments herein, a metal drying salt may suitably refer to those metal salts which may improve the dry time of inks deposited or printed on printable substrates by inkjet printing processes.

In embodiments herein, the multivalent metal drying salt may be selected from the group including calcium chloride, calcium acetate, calcium hydroxide, calcium nitrate, calcium sulfate, calcium sulfite, magnesium chloride, magnesium acetate, magnesium nitrate, magnesium sulfate, magnesium sulfite, aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum chlorohydrate, sodium aluminum sulfate, vanadium chloride, and a combination thereof.

In embodiments herein, the monovalent metal drying salt may be selected from the group including sodium chloride, sodium acetate, sodium carbonate, sodium bicarbonate, sodium hydroxide, sodium silicates, sodium sulfate, sodium sulfite, sodium nitrate, sodium bromide, potassium chloride, potassium acetate, potassium carbonate, potassium bicarbonate, potassium hydroxide, potassium silicates, potassium sulfate, potassium sulfite, potassium nitrate, potassium bromide, lithium chloride, lithium acetate, lithium carbonate, lithium bicarbonate, lithium hydroxide, lithium silicates, lithium sulfate, lithium sulfite, lithium nitrate, lithium bromide, or a combination thereof.

In embodiments herein, any combination of salt may be suitably used.

In embodiments herein, in the size press composition, the water soluble salt may be present in an amount of 3 to 30 parts by weight, based on the weight of the composition. This range includes all values and subranges therebetween, including 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 parts by weight, based on the weight of the composition.

In embodiments herein, in the size press composition, the water soluble salt may be present in an amount of 5 to 20 parts by weight, based on the weight of the composition. This range includes all values and subranges therebetween, including 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 parts by weight, based on the weight of the composition.

In embodiments herein, in the size press composition, the water soluble salt may be present in an amount such that the metal anion of the water soluble salt has the same equivalent weight as the calcium anion based on 3 to 30 parts by weight of calcium chloride, based on the weight of the composition. This range includes all values and subranges therebetween, including 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 parts by weight of calcium chloride, based on the weight of the composition.

In embodiments herein, the size press composition may have a % solids of about 10-30% solids by weight. This range includes all values and subranges therebetween, including about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30% solids by weight, based on the weight of the composition.

In embodiments herein, the size press composition may have a % solids of about 20-30% solids by weight.

In embodiments herein, the term “% solids” refers to the percentage of non-volatile, non-liquid components (by weight) that are present in the sizing, coating, composition, etc.

In embodiments herein, one example of the size press composition may include starch/GCC (2:1 starch:GCC ratio) with Scripset (SMA) surface sizing (5 parts Scripset: 100 parts starch/GCC). In embodiments herein, as an example, the size press formulation may be applied with a rod-metered size press.

In embodiments herein, one example of starch is ethylated starch, one example of pigment is GCC, one example of synthetic surface sizing agent is Scripset SMA, and one example is applying the size press composition with a rod-metered size press.

In embodiments herein, the binder and pigment are suitably present in a binder:pigment weight ratio of about 10:1 to about 1:10. This range includes all values and subranges therebetween, including 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:1; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:2; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:3; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:4; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:5; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:6; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:7; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:8; 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:9; and 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1:10.

In embodiments herein, in the size press composition, the binder and pigment may be present in a binder:pigment weight ratio of about 4:1 to about 1:1.

In embodiments herein, the synthetic surface sizing is suitably present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100. This range includes all values and subranges therebetween, including 2, 3, 4, 5, 6, 7, 8, 9, or 10:100.

In embodiments herein, in the size press composition, the synthetic surface sizing may be present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 3:100 to about 6:100.

In another embodiment, a sized web for paper or paperboard is provided, which includes:

a dried web including cellulosic fibers; and

the size press composition on one or both sides of the dried web.

In embodiments herein, prior to being contacted with the size press composition, the dried web is not coated, i.e., the dried web has a zero or substantially zero surface loading of a coating or sizing present on one or both sides or surfaces of the web. As used herein, the size press composition is considered to be distinct from coatings such as described in U.S. Pat. No. 9,670,621.

In embodiments herein, the sizing may be present on one side, or on both sides of the dried web. In embodiments herein, if present on both sides of the dried web, the sizing may be the same or different on the respective sides.

In embodiments herein, the sizing may include starch, pigment and Scripset. In embodiments herein, the sizing may include binders other than starch. In embodiments herein, the sizing may include a combination of starch and non-starch binders. In embodiments herein, the binders other than starch may have greater “binding strength” than starch and in that case may be used at lower levels than that of starch and still result in coatings that are not “dusty”.

In embodiments herein, other process steps such as drying, coating, and calendering of the paperboard can be performed after the size press treatment, as these subsequent processing steps will not be hindered by these size press treatments, and in some ways can be improved. For example, the size press treatment herein can result in a smoother paperboard, and if desired, can be dried and calendered, resulting in an uncoated (but sized) paperboard with enhanced smoothness and printability. As another example, the paperboard can be coated after the size press treatment, so that subsequent coatings will be smoother, and perhaps can be reduced in thickness and still achieve adequate coverage. As another example, by including the proper amount and type of surface sizing and/or starch cobinders to the size press formulation, holdout for subsequent coatings can be improved so that less water and water soluble binders are absorbed into the paperboard, resulting in stronger coatings and improved barrier properties.

In another embodiment, a coated or uncoated paper or paperboard is provided, which includes the sized web.

In another embodiment, a paper or paperboard is provided, which includes:

a sized web, which includes:

    • a dried web including cellulosic fibers; and
    • a size press composition on one or both sides of the dried web, the size press composition including:
      • binder;
      • pigment;
      • synthetic surface sizing agent; and
      • substantially no water;

wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and

wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

In embodiments herein, the paper or paperboard may be coated or uncoated.

In embodiments herein, the paper or paperboard may include one or more coatings in contact with one or both sides of the sized web.

In embodiments herein, the coatings, e.g., base coat, top coat, or both, may refer to those compositions which may be applied over the sized web, and do not refer to the size press composition per se. In embodiments herein, the surface sizing composition may have a lower solids content than that of the coatings, and the surface sizing composition may penetrate into the dried web somewhat, in forming one embodiment of the sized web. The coatings may suitably and independently contain optional additives, such as, for example, a metal salt drying agents, cationic dye fixing agents, optical brightening agents, fluorescent whitening agents, solvents, diluents, anti-scratch and mar resistance agents, defoamers, rheology modifiers, thickeners, lubricants, dispersants, surfactants, or combination thereof. For example, the coating or coatings may independently contain Alcogum L229™ by Kemira, (styrene acrylic thickener), Berchem 4136™ by Bercen (diglyceride lubricant), Rheocarb 121™ by Coatex, SunKote 455™ by Omnova (calcium stearate), Accumer 9300™ by Dow (acrylic homopolymer), or a combination thereof. The coating compositions may be independently formulated as an aqueous solution, an aqueous slurry, a colloidal suspension, a liquid mixture, a thixotropic mixture, etc.

In embodiments herein, the paper or paperboard may include one or more coatings on one or both sides of the sized web, such as C1S (coated on one side), C2S (coated on both sides), coated C1S, or coated C2S.

In embodiments herein, the paper or paperboard may include a base coat in contact with one or both sides of the sized web.

In embodiments herein, the paper or paperboard may include a base coat one or both sides of the sized web, such as a C1S or C2S coating in contact with sized web.

In embodiments herein, if coated with a base coat on both sides, the base coats may be the same or different.

In embodiments herein, the paper or paperboard may include a top coat in contact with the base coat on one or both sides of the sized web.

In embodiments herein, the paper or paperboard may include a top coat, such as a C1S or C2S coating.

In embodiments herein, if coated with a top coat on both sides, the top coats may be the same or different.

In embodiments herein, a dried web refers to a fibrous web that may be formed, created, produced, etc., on a moving wire of a papermaking machine from an aqueous mixture, furnish, etc., including at least cellulosic fibers, and then dried. In embodiments herein, the web may be suitably dried to contain less than or equal to 10% by weight water. This range includes all values and subranges therebetween, including 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, 0.1% by weight, or less water.

The dried web suitably includes a plurality of cellulosic fibers. The type of cellulosic fiber is not critical, and any such fiber known or suitable for use in paper making can be used. For example, the web can made from pulp fibers derived from hardwood trees, softwood trees, or a combination of hardwood and softwood trees. The fibers may be prepared for use in a papermaking furnish by one or more known or suitable digestion, refining, and/or bleaching operations such as, for example, known mechanical, thermomechanical, chemical and/or semichemical pulping and/or other well known pulping processes. The term, “hardwood pulps” as may be used herein include fibrous pulp derived from the woody substance of deciduous trees (angiosperms) such as birch, oak, beech, maple, and eucalyptus. The Willi, “softwood pulps” as may be used herein include fibrous pulps derived from the woody substance of coniferous trees (gymnosperms) such as varieties of fir, spruce, and pine, as for example loblolly pine, slash pine, Colorado spruce, balsam fir and Douglas fir. In some embodiments, at least a portion of the pulp fibers may be provided from non-woody herbaceous plants including, but not limited to, kenaf, hemp, jute, flax, sisal, or abaca, although legal restrictions and other considerations may make the utilization of hemp and other fiber sources impractical or impossible. Either bleached or unbleached pulp fiber may be utilized. Recycled pulp fibers are also suitable for use.

In embodiments herein, the dried web may suitably contain from 1 to 99 wt % of cellulosic fibers based upon the total weight of the web. In one embodiment, the dried web may contain from 5 to 95 wt % of cellulosic fibers based upon the total weight of the web. These ranges include any and all values and subranges therebetween, for example, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 99 wt %.

In embodiments herein, the dried web may optionally contain from 1 to 100 wt % cellulosic fibers originating from softwood species based upon the total amount of cellulosic fibers in the dried web. In one embodiment, the dried web may contain 10 to 60 wt % cellulosic fibers originating from softwood species based upon the total amount of cellulosic fibers in the dried web. These ranges include 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 wt % and any and all ranges and subranges therein, based upon the total amount of cellulosic fibers in the dried web.

In embodiments herein, the dried web may alternatively or overlappingly contain from 0.01 to 99 wt % fibers from softwood species, based on the total weight of the dried web. In another embodiment, the dried web may contain from 10 to 60 wt % fibers from softwood species based upon the total weight of the dried web. These ranges include any and all values and subranges therein. For example, the dried web may contain not more than 0.01, 0.05, 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 99 wt % softwood based upon the total weight of the dried web.

In embodiments herein, all or part of the softwood fibers may optionally originate from softwood species having a Canadian Standard Freeness (CSF) of from 300 to 750. In one embodiment, the dried web contains fibers from a softwood species having a CSF from 400 to 550. These ranges include any and all values and subranges therebetween, for example, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, and 750 CSF. Canadian Standard Freeness is as measured by TAPPI T-227 standard test.

In embodiments herein, the dried web may optionally contain from 1 to 100 wt % cellulosic fibers originating from hardwood species based upon the total amount of cellulosic fibers in the dried web. In one embodiment, the dried web may contain from 30 to 90 wt % cellulosic fibers originating from hardwood species, based upon the total amount of cellulosic fibers in the dried web. These ranges include 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 wt %, and any and all values and subranges therein, based upon the total amount of cellulosic fibers in the dried web.

In embodiments herein, the dried web may alternatively or overlappingly contain from 0.01 to 99 wt % fibers from hardwood species, based upon the total weight of the dried web. In another embodiment, the dried web may alternatively or overlappingly contain from 60 to 90 wt % fibers from hardwood species, based upon the total weight of the dried web. These ranges include any and all values and subranges therebetween, including not more than 0.01, 0.05, 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99 and 99 wt %, based upon the total weight of the dried web.

In embodiments herein, all or part of the hardwood fibers may optionally originate from hardwood species having a Canadian Standard Freeness of from 300 to 750. In one embodiment, the dried web may contain fibers from hardwood species having CSF values of from 400 to 550. These ranges include 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, and 750 CSF, and any and all ranges and subranges therein.

In embodiments herein, the dried web may optionally contain less refined fibers, for example, less refined softwood fibers, less refined hardwood, or both. Combinations of less refined and more refined fibers are possible. In one embodiment, the dried web contains fibers that are at least 2% less refined than that of fibers used in conventional dried webs. This range includes all values and subranges therebetween, including at least 2, 5, 10, 15, and 20%.

When the dried web contains both hardwood fibers and softwood fibers, the hardwood/softwood fiber weight ratio may optionally range from 0.001 to 1000. In one embodiment, the hardwood/softwood ratio may range from 90/10 to 30/60. These ranges include all values and subranges therebetween, including 0.001, 0.002, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000.

In embodiments herein, the softwood fibers, hardwood fibers, or both may be optionally modified by physical and/or chemical processes. Examples of physical processes include, but are not limited to, electromagnetic and mechanical processes. Examples of electrical modifications include, but are not limited to, processes involving contacting the fibers with an electromagnetic energy source such as light and/or electrical current. Examples of mechanical modifications include, but are not limited to, processes involving contacting an inanimate object with the fibers. Examples of such inanimate objects include those with sharp and/or dull edges. Such processes also involve, for example, cutting, kneading, pounding, impaling, and the like, and combinations thereof.

Non-limiting examples of chemical modifications include conventional chemical fiber processes such as crosslinking and/or precipitation of complexes thereon. Other examples of suitable modifications of fibers include those found in U.S. Pat. Nos. 6,592,717, 6,592,712, 6,582,557, 6,579,415, 6,579,414, 6,506,282, 6,471,824, 6,361,651, 6,146,494, H1,704, 5,731,080, 5,698,688, 5,698,074, 5,667,637, 5,662,773, 5,531,728, 5,443,899, 5,360,420, 5,266,250, 5,209,953, 5,160,789, 5,049,235, 4,986,882, 4,496,427, 4,431,481, 4,174,417, 4,166,894, 4,075,136, and 4,022,965, the entire contents of each of which are hereby incorporated, independently, by reference. Still other examples of suitable modifications of fibers may be found in U.S. Application Nos. 60/654,712, filed Feb. 19, 2005, and Ser. No. 11/358,543, filed Feb. 21, 2006, which may include the addition of optical brighteners (i.e. OBAs) as discussed therein, the entire contents of each of which are hereby incorporated, independently, by reference.

In embodiments herein, the dried web may optionally include “fines.” “Fines” fibers are typically those fibers with average lengths of not more than about 100 μm. Sources of “fines” may be found in SaveAll fibers, recirculated streams, reject streams, waste fiber streams, and combinations thereof. The amount of “fines” present in the dried web can be modified, for example, by tailoring the rate at which streams are added to the paper making process. In one embodiment, the average lengths of the fines are not more than about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 μm, including any and all ranges and subranges therein.

If used, the “fines” fibers may be present in the dried web together with hardwood fibers, softwood fibers, or both hardwood and softwood fibers.

In embodiments herein, the dried web may optionally contain from 0.01 to 100 wt % fines, based on the total weight of the dried web. In one embodiment, the dried web may contain from 0.01 to 50 wt % fines, based upon the total weight of the web. These ranges include all values and subranges therebetween, including not more than 0.01, 0.05, 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 100 wt % fines, based upon the total weight of the dried web.

In embodiments herein, the dried web may alternatively or overlappingly contain from 0.01 to 100 wt % fines, based upon the total weight of the fibers in the dried web. This range includes all values and subranges therebetween, including not more than 0.01, 0.05, 0.1, 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 100 wt % fines, based upon the total weight of the fibers in by the dried web.

In embodiments herein, the paper or paperboard may have a basis weight of from about 8 pt to about 30 pt. This range includes all values and subranges therebetween, including about 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 pt.

In embodiments herein, the paper or paperboard may have a basis weight of from about 10 pt to about 24 pt.

In another embodiment, an article is provided, which includes the paper or paperboard.

In embodiments herein, the article may be suitable for one or more of inkjet, flexo, gravure, or offset printing, or a combination of two or more thereof.

In embodiments herein, article may be selected from the group including packaging, food service item, cup, plate, and a combination thereof. In embodiments herein, the paper or paperboard is in the form of cupstock or platestock.

In embodiments herein, the sized web, paper or paperboard, or article may have improved barrier properties, improved water barrier properties, improved oil barrier properties, improved barrier layer for OGWR coating, improved water barrier for cup and/or platestock, improved (lower) dust properties, improved smoothness for flexo, gravure, and offset printing, or a combination thereof.

In another embodiment, a method is provided, which includes contacting, on a papermaking machine:

a dried web including cellulosic fibers; and

the size press composition;

to form a sized web.

In embodiments herein, contacting the dried web and the size press composition may be carried out at a size press selected from the group including rod-metered size press, puddle size press, blade-metered size press, curtain coater size press, vertical size press, horizontal size press, metering size press, gated roll metering size press, doctor blade metering size press, and a combination thereof.

In embodiments herein, contacting the dried web and the size press composition may be carried out carried out at a rod-metered size press.

In embodiments herein, the base coat may be applied to one or both sides of the sized web, to form a coated paper or paperboard.

In embodiments herein, the base coat formulation may include a standard pigment containing coating designed for flexo and offset printing. For example, the base coat may include 10 to 20 parts latex binder and 100 parts pigment; a barrier coating containing a higher proportion of binder; or a specialty coating containing only latex. The binder is not particularly limiting. Non-limiting examples of the binder include RAP 810™ by Trinseo (styrene acrylate), XU 31669 SB™ latex by Trinseo (styrene butadiene), XU 31695™ by Trinseo (styrene acrylonitrile), Polyco 3960™ by Dow (poly vinyl acetate), Polyco 2160 IPA™ by Dow (poly vinyl acetate), Hypod 1001™ by Dow (polyethylene emulsion), Hypod 9105™ by Dow (polyethylene emulsion), or a combination thereof. Similarly, the pigment is not particularly limiting. Non-limiting examples of pigment include HC (Hydrocarb) 90™ by Omya (ground calcium carbonate), HC (Hydrocarb) 60™ by Omya (ground calcium carbonate), Hydrafine 90W™ by KaMin (clay), and combinations thereof. In some embodiments, the pigment is HC (Hydrocarb) 60™ by Omya (ground calcium carbonate).

In embodiments herein, the pigment in the base coat formulation may include one or more of clay and calcium carbonate.

In embodiments herein, the term, “top” is used merely for convenience and is not intended to imply a particular direction.

In embodiments herein, a top coat may be applied to the base coat on one or both sides of the sized web, to form a coated paper or paperboard.

In embodiments herein, the top coat formulation may include a standard pigment containing coating designed for flexo and offset printing. For example, the top coat formulation may include 10 to 20 parts latex binder and 100 parts pigment; a barrier coating containing a higher proportion of binder; or a specialty coating containing only latex. The binder is not particularly limiting. Non-limiting examples of the binder include RAP 810™ by Trinseo (styrene acrylate), XU 31669 SB™ latex by Trinseo (styrene butadiene), XU 31695™ by Trinseo (styrene acrylonitrile), Polyco 3960™ by Dow (poly vinyl acetate), Polyco 2160 IPA™ by Dow (poly vinyl acetate), Hypod 1001™ by Dow (polyethylene emulsion), Hypod 9105™ by Dow (polyethylene emulsion), or a combination thereof. Similarly, the pigment is not particularly limiting. Non-limiting examples of pigment include HC (Hydrocarb) 90™ by Omya (ground calcium carbonate), HC (Hydrocarb) 60™ by Omya (ground calcium carbonate), Hydrafine 90W™ by KaMin (clay), and combinations thereof. In some embodiments, the pigment is HC (Hydrocarb) 90™ by Omya (ground calcium carbonate), Hydrafine 90W™ by KaMin (clay), or a combination thereof.

In embodiments herein, the pigment in the top coat formulation may include one or more of clay and calcium carbonate.

In embodiments herein, one or more of drying, coating, or calendaring the sized web, or a combination of two or more thereof may be further carried out.

EXAMPLES

The examples herein are provided for illustration only and are not intended to be limiting unless otherwise specified.

Example 1

Coated paper substrates were made on the Trinseo pilot coater in Midland, Mich. (Table 1). The base paperboard was a 14 point uncoated cupstock having no size press treatment. Surface size compositions (as shown in Table 1 below) were applied to both sides of this uncoated cupstock at the rate of 1300 feet per minute (fpm) using a rod metered size press and dried using an infrared (IR) dryer, followed by a forced air oven. Comparative Samples S-1 and S-2 had a control surface size composition applied, consisting of a 6% solids solution of PG-270 ethylated corn starch, which is a size press formulation that is similar to many commercial paperboards currently available. Exemplary Samples S-3 and S-4 had a pigmented size press composition applied in accordance with an embodiment of the present invention. Subsequently, all four samples were coated on one side of the paperboard with a base coat and then a top coat. The base coats were applied using a blade coater in the stiff blade mode, while the top coats were applied using a blade coater in the bent blade mode. Both coatings were dried after coating using an infrared (IR) dryer, followed by a forced air oven. The coating formulations for the base coats and the top coats are listed in Table 1.

The components, layers, and properties of these coated paper substrates are shown in Table 1 below:

TABLE 1 Comp Comp Sample Sample Sample Sample S-1 S-2 S-3 S-4 Paper Substrate Caliper (points) 14  14  14 14 Basis Weight1 165  165  165  165  Size Press Composition2 Starch binder3 100  100  66 66 Pigment4 0 0 33 33 Synthetic Surface Sizing 0 0 10 10 Agent5 Salt6 0 0  1  1 % solids 6 6 25 25 Pick-up1 2 2  6  6 Base Coat Pigment7 100  100  100  100  Latex Binder 148  139   148  139 Dispersant10   0.18   0.18    0.18    0.18 Dispersant11   0.3   0.3   0.3   0.3 Thickener12   0.2   0.2   0.2   0.2 Coat Weight1 8 8  7  7 Top Coat Pigment, GCC4 70  70  70 70 Pigment, Clay13 30  30  30 30 Latex Binder   14.58   13.59   14.58   13.59 Dispersant10   0.19   0.19    0.19    0.19 Dispersant11   0.1   0.1   0.1   0.1 Thickener12   0.3   0.3   0.3   0.3 Lubricant14 1 1  1 Coat Weight1 7 8  8  8 Test Results Hagerty Permeability 232  157  886  556  (sec per 10 cc) Parker Print Surf   1.88   1.94    1.52    1.53 Flexo Print Mottle  15.5  11.1   6.6   7.4 1In lbs/3 msf 2Amounts (estimated) in dry parts 3From Ingredion, PG 270 ethylated corn starch 4From Omya, Hydrocarb 90 GCC 5From Solenis, Scripset 745 SMA 6From Aldrich, Calcium Chloride 7From Omya, Hydrocarb 60 GCC 8From Trinseo, XU31695, which is a styrene-acrylic-acrylonitrile copolymer latex 9From Trinseo, RAP830, which is a styrene-acrylic copolymer latex. 10From Dow, Accumer 9300 11From Omya, Rheocarb 121 12From Kemira, FennoFlow L229 13From KaMin, Hydrafine 90W clay 14From Omnova, SunKote 455 calcium stearate

The four coated paperboard samples were then tested for Hagerty Permeability and Parker Print Surf. Hagerty Permeability is a measure of the porosity of the coated paperboard, measuring the time in seconds for a 10 cubic centimeter volume of air to pass through the sample at a fixed pressure. The higher the number, the longer time it takes the air to pass through the coated paperboard, and hence the less porous the paperboard. Parker Print Surf is a measure of the surface roughness over a small area of the sample surface. The higher the number, the rougher the sample. Samples were also tested for flexo print mottle evaluation. The higher the number, the more mottle can be detected on the printed paperboard sample. The results of these tests are listed in Table 1.

From the coating compositions listed in Table 1, it should be noted that Samples S-1 and S-3 have the same base coat and top coat coating compositions, but differ in that Comparative Sample S-1 has a size press composition consisting of starch only, and Exemplary Sample S-3 has a size press formulation in accordance with an embodiment of the present invention. The results in Table 1 show that Exemplary Sample S-3 has a higher Hagerty Permeability value than Comparative Sample S-1, which indicates that Exemplary Sample S-3 is less porous than Comparative Sample S-1. Exemplary Sample S-3 also has a significantly smoother surface than Comparative Sample S-1, as indicated by the lower value for Parker Print Surf, as well as the lower flexo print mottle. These observations also hold true for Samples S-2 (Comparative) and S-4 (Exemplary), which have the same coating formulations but different size press compositions. The coating formulations between S-1 and S-3 and S-2 and S-4 differ only in the latex binder used.

Example 2

Coated paper substrates were made on the Trinseo pilot coater in Midland, Mich. (Table 2). The base paperboard was a 14 point uncoated cupstock having no size press treatment. Surface size compositions (as shown in Table 2 below) were applied to both sides of this uncoated cupstock at the rate of 1300 feet per minute (fpm) using a rod metered size press and dried using an infrared (IR) dryer, followed by a forced air oven. Comparative Samples S-5 and S-9 had a control surface size composition applied, consisting of a 6% solids solution of PG-270 ethylated corn starch, which is a size press formulation that is similar to many commercial paperboards currently available. Exemplary Samples S-6, S-7, S-8, S-10, S-11, and S-12 had a pigmented size press composition applied in accordance with an embodiment of the present invention. Subsequently, all eight samples were coated on one side of the paperboard with a base coat and then a top coat. The base coats were applied using a blade coater in the stiff blade mode, while the top coats were applied using a blade coater in the bent blade mode. Both coatings were dried after coating using an infrared (IR) dryer, followed by a forced air oven. The coating formulations for the base coats and the top coats are listed in Table 2.

The components, layers, and properties of these coated paper substrates are shown in Table 2 below:

TABLE 2 Comp Comp Sample Sample Sample Sample Sample Sample Sample Sample S-5 S-6 S-7 S-8 S-9 S-10 S-11 S-12 Paper Substrate Caliper (points) 14 14 14 14 14 14 14 14 Basis Weight1 165  165  165  165  165  165  165  165  Size Press Composition2 Starch binder 1003   663  664  664 1003   663  664  664 Pigment5  0 33 33 33  0 33 33 33 Synthetic  0   56   56  107  0   56   56  107 Surface Sizing Agent % solids  6 25 25 25  6 25 25 25 Pick-up1  2  5  5  4  2  5  5  4 Base Coat Pigment, GCC8 60 60 60 60 60 60 60 60 Pigment, Clay5 40 40 40 40 40 40 40 40 Latex Binder  209  209  209  209  2010  2010  2010  2010 Dispersant11    0.18    0.18    0.18    0.18    0.18    0.18    0.18    0.18 Thickener12   0.2   0.2   0.2   0.2   0.2   0.2   0.2   0.2 Coat Weight1  7  6  6  5  7  7  7  7 Top Coat Pigment, GCC13 60 60 60 60 60 60 60 60 Pigment, Clay5 40 40 40 40 40 40 40 40 Latex Binder10 18 18 18 18 18 18 18 18 Dispersant11    0.19    0.19    0.19    0.19    0.19    0.19    0.19    0.19 Thickener12    0.05    0.05    0.05    0.05    0.05    0.05    0.05    0.05 Lubricant14  1  1  1  1  1  1  1  1 Coat Weight1  8  7  8  7  8  8  8  8 Test Results Hagerty 921  1606  1586  1522  604  1180  1390  1252  Permeability (sec per 10 cc) Hot Corn Oil   26.5   19.8   13.3   13.6   27.2   20.1   16.5   18.5 Test 1In lbs/3 msf 2Amounts (estimated) in dry parts 3From Ingredion, PG 270, ethylated corn starch 4From Ingredion, FilmCote 370, corn starch 5From KaMin, Hydrafine 90W, clay 6From Solenis, IP Size 2000, AKD 7From Solenis, Scripset 745, SMA 8From Omya, Hydrocarb 60 GCC 9From Trinseo, XU31669, styrene-butadiene copolymer latex 10From Trinseo, RAP810, styrene-acrylic copolymer latex. 11From Dow, Accumer 9300 12From Kemira, FennoFlow L229 13From Omya, Hydrocarb 90, GCC 14From Berchem, Berchem 4136

The eight coated paperboard samples were then tested for Hagerty Permeability and Hot Corn Oil holdout. Hagerty Permeability is a measure of the porosity of the coated paperboard, measuring the time in seconds for a 10 cubic centimeter volume of air to pass through the sample at a fixed pressure. The higher the number, the longer time it takes the air to pass through the coated paperboard, and hence the less porous the paperboard. The Hot Corn Oil test is conducted by placing a measured amount of corn oil at 60° C. onto the paperboard sample. Once the paper has cooled down to room temperature, the excess corn oil is removed, and the oil-containing paperboard is left at room temperature for 24 hours. The Y-value brightness of the paperboard is then measured, and the change in Y-value brightness before and after the test is reported. The higher number, the more corn oil was absorbed by the paperboard sample.

The aforementioned Hot Corn Oil test is described in more detail in the patent application WO2009142739A1 in relevant part as follows: Place samples of the coated base paper (8.3 cm by 8.3 cm) with the coated side down and against a Leneta Scrub Chart. Make an initial Y-value reading of the coated base paper from the middle of the sample using a spectrophotometer. Then, secure the samples of the coated base paper to a sheet of clean Plexiglas® with the coated side up. Use a circle template to draw a 5.08 cm diameter circle around the middle of the coated base paper samples. Use a hot glue gun to deposit a bead of glue along the circle to create a “glue dam.” Allow the glue dam to cool and harden for a minimum of 15 minutes at room temperature. Remove 60° C. pre-heated corn oil from an oven set at 60° C. Apply one (1) ml of the hot corn oil to the coated base paper in the area defined by the glue dam. The oil will spread to cover the circle. Place the oil-covered samples of the coated base papers into the oven set at 60° C. After a scheduled time interval, remove the samples of the coated base papers from the oven and placed on a lab bench to cool to room temperature. Once the samples are at room temperature, wipe the excess oil off the surface of the samples of the coated base paper. Remove the samples of the coated base paper from the Plexiglas® and place with the surface treated with the corn oil (oil-stain side) down on a plain black Leneta Chart. Read the Y-value of the middle of the square using the spectrophotometer. The results of these tests are listed in Table 2.

From the coating compositions listed in Table 2, it should be noted that samples S-5 through S-8 have the same base coat and top coat coating compositions, but differ in that Comparative sample S-5 has a size press composition consisting of starch only, and Exemplary samples S-6 through S-8 have a size press formulation in accordance with an embodiment of the present invention. The results in Table 2 show that Exemplary samples S-6 through S-8 have a higher Hagerty Permeability value than Comparative sample S-5, which indicates that Exemplary samples S-6 through S-8 are less porous than Comparative sample S-5. Exemplary Samples S-6 through S-8 also have a better oil holdout (less hot corn oil absorbed) than Comparative sample S-5. This is confirmation of the lower porosity of Exemplary samples S-6 through S-8, as seen in the Hagerty Permeability test. These observations also hold true for Samples S-9 through S-12, which have the same coating formulations but different size press compositions. The coating formulations between sample S-5 through S-8 and samples S-9 through S-12 differ only in the latex binder used in the base coat.

All documents, patents, journal articles and other materials cited in the present application are hereby incorporated by reference, the same as if set forth at length.

Although the present invention has been fully described in conjunction with several embodiments thereof with reference to the accompanying drawings, it is to be understood that various changes and modifications may be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.

Claims

1. A size press composition for paper or paperboard, comprising:

binder;
pigment;
synthetic surface sizing agent; and
water;
wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and
wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

2. The size press composition of claim 1, wherein the binder comprises one or more of natural product, casein, soy protein, fatty acid salts and copolymers, water soluble polymer, water soluble starch co-binder, polyvinyl alcohol, poly acrylic acid, poly acrylic acid salt, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polymer emulsion, acrylate, styrene acrylate, styrene butadiene, styrene acrylonitrile, polyurethane, polyvinyl acetate, polyethylene emulsion, polyethylene (PE) polymers; polyethylene terephthalate (PET) polymers; polyhydroxyalkanoate (PHA) polymers; polylactic acid (PLA) polymers; polyglycolic acid (PGA) polymers; polyvinyl acetate polymers; waxes; polyurethane polymers; or epoxy resins, starch, high-amylose corn starch, waxy corn starch, tapioca starch, cationic starch, ethylated starch, oxidized starch, corn starch, potato starch, rice starch, dent corn starch, waxy starch, modified starch, FilmKote™ by Ingredion, FilmKote 370™ by Ingredion (modified starch), Aquabloc™ by Aquasol, Aquabloc 403™ by Aquasol (starch), Flex Starch™ by Tate and Lyle, Clear-Cote 640™ by Tate and Lyle (waxy starch), PG270™ by Ingredion (ethylated starch), RAP 810™ by Trinseo (styrene acrylate), XU 31669 SB™ latex by Trinseo (styrene butadiene), XU 31695™ by Trinseo (styrene acrylonitrile), Polyco 3960™ by Dow (poly vinyl acetate), Polyco 2160 IPA™ by Dow (poly vinyl acetate), binder, Hypod 1001™ by Dow (polyethylene emulsion), Hypod 9105™ by Dow (polyethylene emulsion), or a combination thereof.

3. The size press composition of claim 1, wherein the binder comprises one or more natural products such as casein, soy protein, and fatty acid salts and copolymers, water soluble polymers such as polyvinyl alcohol, poly acrylic acid and salts, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, etc, and polymer emulsions such as acrylates, styrene acrylates, styrene butadienes, polyurethanes, polyvinyl acetates, polyethylene (PE) polymers; polyethylene terephthalate (PET) polymers; polyhydroxyalkanoate (PHA) polymers; polylactic acid (PLA) polymers; polyglycolic acid (PGA) polymers; polyvinyl acetate polymers; waxes; polyurethane polymers; or epoxy resins, and their copolymers and derivatives.

4. The size press composition of claim 1, wherein the binder comprises a starch selected from the group consisting of high-amylose corn starch, waxy corn starch, tapioca starch, cationic starch, ethylated starch, oxidized starch, corn starch, potato starch, rice starch, dent corn starch, waxy starch, modified starch, FilmKote™ by Ingredion, FilmKote 370™ by Ingredion (modified starch), Aquabloc™ by Aquasol, Aquabloc 403™ by Aquasol (starch), Flex Starch™ by Tate and Lyle, Clear-Cote 640™ by Tate and Lyle (waxy starch), PG270™ by Ingredion (ethylated starch), and a combination thereof.

5. The size press composition of claim 1, wherein the binder comprises a water-soluble polymer binder selected from the group consisting of starch binders, cellulosic binders, polyvinyl alcohol binders, polyacrylic acid binders, polymethacrylic acid binders, polyvinylamine binders, polyacrylamide binders, polyether binders, sulfonated polystyrene binders, carboxylated polystyrene binders, and a combination thereof.

6. The size press composition of claim 5, wherein the water-soluble polymer binder is a starch binder.

7. The size press composition of claim 1, wherein the binder comprises a polymer latex binder selected from the group consisting of styrene butadiene rubber latexes, acrylic polymer latexes, polyvinyl acetate latexes, styrene acrylic copolymer latexes, polyurethane latexes, starch/acrylic copolymer latexes, starch/styrene acrylic copolymer latexes, polyvinyl alcohol (PVOH)/styrene acrylic copolymer latexes, PVOH/acrylic copolymer latexes, and a combination thereof.

8. The size press composition of claim 7, wherein the polymer latex binder is a styrene-acrylic latex binder.

9. The size press composition of claim 1, wherein the binder is ethylated starch.

10. The size press composition of claim 1, wherein the pigment is selected from the group consisting of ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), clay, kaolin clay, talc, mica, calcium sulfate, absorbent plastic pigment particles, calcined clay pigment particles, titanium dioxide pigment particles, barium sulfate pigment particles, silica pigment particles, zeolite pigment particles, fumed silica pigment particles, alumina pigment particles, bentonite clay pigment particles, HC (Hydrocarb) 90™ by Omya (ground calcium carbonate), HC (Hydrocarb) 60™ by Omya (ground calcium carbonate), Hydrafine 90W™ by KaMin (clay), and a mixture thereof.

11. The size press composition of claim 1, wherein the pigment is ground calcium carbonate (GCC).

12. The size press composition of claim 1, wherein the synthetic surface sizing agent is selected from the group consisting of styrene maleic anhydride (SMA), alkyl ketene dimer (AKD), AKD (IP Size 2000)™ by Solenis (alkyl ketene dimer), Scripset 745™ by Solenis (styrene maleic anhydride), styrene acrylic emulsion (SAE), polymer emulsions with a surface energy of 50 dynes or less after drying, and a combination thereof.

13. The size press composition of claim 1, wherein the synthetic surface sizing agent is styrene maleic anhydride (SMA).

14. The size press composition of claim 1, wherein the synthetic surface sizing agent is Scripset™.

15. The size press composition of claim 1, further comprising one or more water soluble salt.

16. The size press composition of claim 15, wherein the water soluble salt is one or more of a multivalent cationic metal salt, an inorganic salt, an organic salt, or a combination thereof.

17. The size press composition of claim 15, wherein the water soluble salt is one or more multivalent cationic metal salt, inorganic salt, organic salt, or combination thereof selected from the group consisting of calcium chloride, calcium acetate, calcium magnesium acetate, calcium nitrate, calcium hydroxide, magnesium chloride, magnesium sulfate, magnesium nitrate, magnesium sulfate, aluminum chloride, aluminum nitrate, aluminum chlorohydrate, aluminum sulfate, sodium aluminum sulfate, vanadium chloride, and a combination thereof.

18. The size press composition of claim 15, wherein the water soluble salt is calcium chloride.

19. The size press composition of claim 15, wherein the water soluble salt is a metal drying salt, multivalent metal drying salt, monovalent metal drying salt, or a combination thereof.

20. The size press composition of claim 19, wherein the multivalent metal drying salt is selected from the group consisting of calcium chloride, calcium acetate, calcium hydroxide, calcium nitrate, calcium sulfate, calcium sulfite, magnesium chloride, magnesium acetate, magnesium nitrate, magnesium sulfate, magnesium sulfite, aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum chlorohydrate, sodium aluminum sulfate, vanadium chloride, and a combination thereof.

21. The size press composition of claim 19, wherein the monovalent metal drying salt is selected from the group consisting of sodium chloride, sodium acetate, sodium carbonate, sodium bicarbonate, sodium hydroxide, sodium silicates, sodium sulfate, sodium sulfite, sodium nitrate, sodium bromide, potassium chloride, potassium acetate, potassium carbonate, potassium bicarbonate, potassium hydroxide, potassium silicates, potassium sulfate, potassium sulfite, potassium nitrate, potassium bromide, lithium chloride, lithium acetate, lithium carbonate, lithium bicarbonate, lithium hydroxide, lithium silicates, lithium sulfate, lithium sulfite, lithium nitrate, lithium bromide, or a combination thereof.

22. The size press composition of claim 15, wherein the water soluble salt is present in an amount of 3 to 30 parts by weight, based on the weight of the composition.

23. The size press composition of claim 15, wherein the water soluble salt is present in an amount of 5 to 20 parts by weight, based on the weight of the composition.

24. The size press composition of claim 15, wherein the water soluble salt is present in an amount such that the metal anion of the water soluble salt has the same equivalent weight as the calcium anion based on 3 to 30 parts by weight of calcium chloride, based on the weight of the composition.

25. The size press composition of claim 1, which further comprises a % solids of about 10-30% solids by weight.

26. The size press composition of claim 1, which further comprises a % solids of about 20-30% solids by weight.

27. The size press composition of claim 1, wherein the binder and pigment are present in a binder:pigment weight ratio of about 4:1 to about 1:1.

28. The size press composition of claim 1, wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 3:100 to about 6:100.

29. A sized web, for paper or paperboard, comprising:

a dried web comprising cellulosic fibers; and
the size press composition of claim 1 on one or both sides of the dried web.

30. A coated or uncoated paper or paperboard, comprising the sized web of claim 29.

31. A paper or paperboard, comprising:

a sized web, comprising: a dried web comprising cellulosic fibers; and a size press composition on one or both sides of the dried web, the size press composition comprising: binder; pigment; synthetic surface sizing agent; and substantially no water;
wherein the binder and pigment are present in a binder:pigment weight ratio of about 10:1 to about 1:10; and
wherein the synthetic surface sizing is present in a synthetic surface sizing agent:(binder and pigment) weight ratio of about 2:100 to about 10:100.

32. The paper or paperboard of claim 31, which is uncoated.

33. The paper or paperboard of claim 31, further comprising one or more coatings in contact with one or both sides of the sized web.

34. The paper or paperboard of claim 33, wherein the one or more coatings are C1S (coated on one side), C2S (coated on both sides), coated C1S, or coated C2S.

35. The paper or paperboard of claim 31, further comprising a base coat in contact with one or both sides of the sized web.

36. The paper or paperboard of claim 35, wherein the base coat is a C1S or C2S coating in contact with sized web.

37. The paper or paperboard of claim 35, further comprising a top coat in contact with the base coat on one or both sides of the sized web.

38. The paper or paperboard of claim 37, wherein the top coat is a C1S or C2S coating.

39. The paper or paperboard of claim 31, having a basis weight of from about 8 pt to about 30 pt.

40. The paper or paperboard of claim 31, having a basis weight of from about 10 pt to about 24 pt.

41. An article, comprising the paper or paperboard of claim 31.

42. The article of claim 41, which is suitable for one or more of inkjet, flexo, gravure, or offset printing, or a combination of two or more thereof.

43. The article of claim 41, which is selected from the group consisting of packaging, food service item, cup, plate, and a combination thereof.

44. The article of claim 41, which has improved barrier properties, improved smoothness for flexo, gravure, and offset printing, or a combination thereof.

45. A method, comprising contacting, on a papermaking machine:

a dried web comprising cellulosic fibers; and
the size press composition of claim 1;
to form a sized web.

46. The method of claim 45, wherein the contacting is carried out at a size press selected from the group consisting of rod-metered size press, puddle size press, blade-metered size press, curtain coater size press, vertical size press, horizontal size press, metering size press, gated roll metering size press, doctor blade metering size press, and a combination thereof.

47. The method of claim 45, wherein the contacting is carried out at a rod-metered size press.

48. The method of claim 45, further comprising applying a base coat to one or both sides of the sized web, to form a coated paper or paperboard.

49. The method of claim 48, wherein the base coat is applied from a base coat formulation comprising a standard pigment containing coating designed for flexo and offset printing, comprised of 10 to 20 parts latex binder and 100 parts pigment; a barrier coating containing a higher proportion of binder; or a specialty coating containing only latex.

50. The method of claim 49, wherein the pigment comprises one or more of clay and calcium carbonate.

51. The method of claim 48, further comprising applying a top coat to the base coat on one or both sides of the sized web, to form a coated paper or paperboard.

52. The method of claim 51, wherein the top coat is applied from a top coat formulation comprising a standard pigment containing coating designed for flexo and offset printing, comprised of 10 to 20 parts latex binder and 100 parts pigment; a barrier coating containing a higher proportion of binder; or a specialty coating containing only latex.

53. The method of claim 52, wherein the pigment comprises one or more of clay and calcium carbonate.

54. The method of claim 45, further comprising one or more of drying, coating, or calendaring the sized web, or a combination of two or more thereof.

Patent History
Publication number: 20190177920
Type: Application
Filed: Dec 11, 2017
Publication Date: Jun 13, 2019
Inventor: Michael Francis Koenig (Paducah, KY)
Application Number: 15/837,577
Classifications
International Classification: D21H 21/16 (20060101); D21H 19/54 (20060101); D21H 19/58 (20060101); D21H 19/38 (20060101); D21H 19/40 (20060101); D21H 19/84 (20060101); D21H 19/82 (20060101); D21J 1/08 (20060101);