Biorenewable adhesives for inks and overprint varnishes

Abstract

Disclosed herein are biorenewable adhesives for inks and varnishes, as well as methods of synthesizing and using adhesive compositions.

Description

Technical Field

[0001] The present disclosure relates generally to water-based inks and overprint varnishes, and more particularly to highly biorenewable aqueous emulsion binders for use in these inks and varnishes, and to methods of synthesizing and using the emulsion compositions. Background Art

[0002] Water-based inks often contain water-insoluble materials, such as particulate materials. Over time, these materials can settle out of the ink and form a sediment at the bottom of the container. This sedimentation can occur between the time of manufacture and the time of printing. To limit the amount of sedimentation of these particulate components, water-based polyurethanes and polyamides have been included in the ink composition.

[0003] A drawback of prior art inks, including polyurethane and other acrylic polymer materials, is that they are produced from fossil fuels. The manufacture and use of such components depletes the Earth's natural resources and pollutes the environment. In recent years, ink and varnish formulators have turned to environmentally friendly methods to combat greenhouse gas emissions and, where possible, avoid landfills with single-use carbon products. Since many components used in ink and varnish products are carbon-based, more environmentally friendly methods in which organic components are produced from renewable carbon sources are desirable. Summary of the Invention

[0004] Disclosed herein is a method for preparing a polymer emulsion containing high biorenewables. The disclosure further provides water-based inks and varnishes comprising a high renewable content rosin ester and a water-insoluble particulate material in an aqueous dispersion.

[0005] In one form thereof, the present disclosure provides a high biorenewable emulsion composition suitable for use as an adhesive, the emulsion composition comprising: (i) a rosin ester; (ii) a copolymerizable monomer; and (iii) water.

[0006] In its second form, the present disclosure provides a method for preparing a polymer emulsion containing high biorenewables, the method comprising: (i) providing a resin dispersion comprising at least one resin in an aqueous solution; (ii) adding at least one initiator and a polymerization mixture to the resin dispersion, the polymerization mixture comprising at least one copolymerizable monomer; and (iii) preparing the polymer emulsion in water by free radical emulsion polymerization of the polymerization mixture, the resin dispersion, and the initiator. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0008] Figure 1 are pictures showing drawdowns of ink formulations containing the binder with biorenewable content of Example 1 (left and right) versus an ink formulation containing standard Joncryl ECO 2189 (center) using a dispersion of pigment Flexiverse BFD-1121 in a standard ink formulation on Leneta card 3NT-31.

[0009] Figure 2 are pictures showing drawdowns of an ink formulation containing the binder with biorenewable content of Example 2 (left) versus an ink formulation containing standard Joncryl ECO 2177 (right) using a dispersion of pigment Flexiverse BFD-1121 in a standard ink formulation on Leneta card 3NT-31. DETAILED DESCRIPTION

[0010] I. Definitions

[0011] As used herein, the term "biorenewable" refers to any substance derived from renewable raw materials. The presence and amount of "biorenewable" substances are measured, for example, under the procedure described in ASTM D6866-18. A composition can be considered "biorenewable", for example, if it contains at least 20 wt.% "biorenewable" components, particularly 20% to 60% by weight "biorenewable" components, particularly 30% to 50% by weight "biorenewable" components.

[0012] As used herein, the terms "comprising" and variations thereof are used synonymously with the terms "including" and variations thereof and are open, non-limiting terms. Although the terms "comprising" and "including" are used herein to describe various embodiments, the terms "consisting essentially of" and "consisting of" may be used in place of "comprising" and "including" to provide more specific embodiments, and these terms are also disclosed. As used in this disclosure and the appended claims, the singular forms "a / an," "the," include plural referents unless the context clearly dictates otherwise. Disclosure of percentage ranges and other ranges herein includes disclosure of the endpoints of the range and any integers provided within the range.

[0013] II. Emulsion adhesives containing high biorenewables

[0014] The present disclosure provides highly biorenewable emulsion binders for inks and overprint varnishes.

[0015] Emulsion adhesives may comprise a resin, a copolymerizable monomer, and water.

[0016] One aspect of the invention claimed herein relates to a method for preparing a polymer emulsion containing high biorenewables, the method comprising at least the steps of:

[0017] (i) providing a resin dispersion comprising at least one resin in an aqueous solution;

[0018] (ii) adding at least one initiator and a polymerization mixture to the resin dispersion, the polymerization mixture comprising at least one copolymerizable monomer; and

[0019] (iii) preparing a polymer emulsion in water by free radical emulsion polymerization of the polymerization mixture, the resin dispersion and the initiator.

[0020] The resin can be a carrier resin. The resin can be derived in whole or in part from a biorenewable source. Suitable sources can include, for example, plants, trees, and by-products of wood pulping processes.

[0021] The biorenewable resin may include a rosin ester. Suitable rosin esters may include fumarate esters. For example, Filtrez 531 is a rosin fumarate ester available from Lawter. Additionally, XR2780 from Lawter may be used.

[0022] The rosin ester can have an acid value of about 125 mg KOH / g or greater, 150 mg KOH / g or greater, about 155 mg KOH / g or greater, about 160 mg KOH / g or greater, about 165 mg KOH / g or greater, about 170 mg KOH / g or greater, about 175 mg KOH / g or less, about 180 mg KOH / g or less, about 185 mg KOH / g or less, about 190 mg KOH / g or less, about 195 mg KOH / g or less, about 200 mg KOH / g or less, or any value encompassed by these endpoints.

[0023] The number average molecular weight (Mn) of the rosin ester can be about 600 g / mol or greater, about 620 g / mol or greater, about 640 g / mol or greater, about 660 g / mol or greater, about 680 g / mol or greater, about 700 g / mol or less, about 720 g / mol or less, about 740 g / mol or less, about 760 g / mol or less, about 780 g / mol or less, about 800 g / mol or less, or any value encompassed by these endpoints.

[0024] The weight average molecular weight (Mw) of the rosin ester can be about 1500 g / mol or greater, about 2000 g / mol or greater, about 2500 g / mol or greater, about 3000 g / mol or greater, about 3500 g / mol or greater, about 4000 g / mol or greater, about 4500 g / mol or less, about 5000 g / mol or less, about 5500 g / mol or less, about 6000 g / mol or less, about 6500 g / mol or less, about 7000 g / mol or less, about 10,000 g / mol or less, about 15,000 g / mol or less, or any value encompassed by these endpoints.

[0025] The rosin ester can be present in the polymer emulsion in an amount of 40 wt.% or greater, 45 wt.% or greater, 50 wt.% or greater, 55 wt.% or greater, 60 wt.% or greater, 65 wt.% or greater, 70 wt.% or greater, 75 wt.% or greater, 80 wt.% or greater, 85 wt.% or greater, 90 wt.% or greater, or 95 wt.% or greater, based on the total weight of the polymer emulsion composition.

[0026] When preparing the polymer, the rosin ester can be dispersed in an aqueous solution. Suitable aqueous solutions can include, for example, aqueous ammonia. The concentration of the rosin ester in the aqueous ammonia can be about 15% or greater, about 20% or greater, about 25% or greater, about 30% or less, about 35% or less, or about 40% or less, as determined by an oven (150°C, 30 min) or a microwave solids analyzer.

[0027] A surfactant may then be added to the dispersion of the rosin ester in the aqueous phase. Suitable surfactants may include, for example, Poly Step A16-22 (sodium dodecylbenzene sulfonate from Stephan), Disponil AFX1080, or Calfax DB45. The surfactant may be present in the reaction mixture in an amount of about 0.1 wt.% or greater, about 0.2 wt.% or greater, about 0.3 wt.% or greater, about 0.4 wt.% or greater, about 0.5 wt.% or greater, about 0.6 wt.% or less, about 0.7 wt.% or less, about 0.8 wt.% or less, about 0.9 wt.% or less, about 1 wt.% or less, or any value encompassed by these endpoints.

[0028] The emulsion can then be initiated by adding a redox initiator. Suitable redox initiators can include redox initiators such as, for example, isoascorbic acid (IAA), tert-butyl hydroperoxide (TBHP), sodium isoascorbate, sodium metabisulfite, or combinations thereof.

[0029] The initiator can be fed to the reaction mixture over a period of about 60 minutes or more, about 70 minutes or more, about 80 minutes or more, about 90 minutes or less, about 100 minutes or less, about 110 minutes or less, about 120 minutes or less, or any value encompassed by these endpoints.

[0030] The initiator can be fed to the reaction mixture at a temperature of about 60°C or more, about 65°C or more, about 70°C or less, about 75°C or less, about 80°C or less, or any value encompassed by these endpoints.

[0031] A catalyst may also be added. Suitable catalysts may include, for example, copper(II) sulfate (CuSO4) and iron(II) sulfate.

[0032] In some embodiments, the emulsion polymerization monomers may include styrene acrylic-based copolymers and acrylic-based copolymers. Acrylic-based copolymers include copolymers derived from one or more (meth)acrylate monomers. The acrylic-based copolymers may be pure acrylic polymers (i.e., copolymers derived primarily from (meth)acrylate monomers), styrene-acrylic polymers (i.e., copolymers derived from styrene and one or more (meth)acrylate monomers), or vinyl-acrylic polymers (i.e., copolymers derived from one or more vinyl ester monomers and one or more (meth)acrylate monomers).

[0033] Exemplary acrylate and methacrylate monomers include, but are not limited to, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, 2-methylheptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, alkyl crotonates, vinyl acetate, di-n-butyl maleate, Ester, dioctyl maleate, hydroxyethyl (meth)acrylate, allyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxy (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-propylheptyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, caprolactone (meth)acrylate, polypropylene glycol mono(meth)acrylate, polyethylene glycol (meth)acrylate, benzyl (meth)acrylate, hydroxypropyl (meth)acrylate, methyl polyethylene glycol (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and combinations thereof.

[0034] The emulsion polymerization mixture may also include one or more soft ethylenically unsaturated monomers, and one or more hard ethylenically unsaturated monomers. As used herein, the term "soft ethylenically unsaturated monomer" refers to an ethylenically unsaturated monomer that, when homopolymerized, forms a polymer having a glass transition temperature of 0°C or less as measured using differential scanning calorimetry (DSC). Soft ethylenically unsaturated monomers are known in the art and include, for example, ethyl acrylate (T g = -24°C), butyl acrylate (n-butyl acrylate, T g = -54°C), sec-butyl acrylate (T g = -26°C), sec-butyl acrylate (T g = -26°C), isobutyl acrylate (T g = -24°C), n-hexyl acrylate (T g = -45°C), n-hexyl methacrylate (T g =-5°C), 2-ethylhexyl acrylate (T g = -85°C), 2-ethylhexyl methacrylate (Tg = -10°C), octyl methacrylate (T g = -20°C), n-decyl methacrylate (T g = -30°C), Isodecyl Acrylate (T g = -55°C), dodecyl acrylate (T g = -3°C), dodecyl methacrylate (T g = -65°C), 2-ethoxyethyl acrylate (T g =-50°C), 2-methoxy acrylate (T g = -50°C), and 2-(2-ethoxyethoxy)ethyl acrylate (T g = -70°C).

[0035] In some embodiments, the emulsion polymerization mixture may include a soft ethylenically unsaturated monomer that, when homopolymerized, forms a polymer having a low glass transition temperature (as measured by ASTM D3418-15) of about -30°C or more, about -25°C or more, about -24°C or more, about -23°C or more, about -22°C or more, about -21°C or more, about -20°C or more, about -19°C or less, about -18°C or less, about -17°C or less, about -16°C or less, about -15°C or less, about -10°C or less, or any value encompassed by these endpoints, as measured using DSC. For example, the first theoretical T g It can be from about -25°C to about -15°C, from about -18°C to about -10°C, from about -22°C to about -15°C, etc. In some embodiments, the emulsion polymerization mixture can include a soft ethylenically unsaturated monomer that, when homopolymerized, forms a polymer having a moderate glass transition temperature (as measured by ASTM D3418-15) of 10°C or more, 12°C or more, 15°C or more, 17°C or more, 20°C or more, 22°C or more, 25°C or less, 27°C or less, 30°C or less, 32°C or less, 35°C or less, or any value encompassed by these endpoints, as measured using DSC. For example, the first theoretical T gThe temperature may be from about 10°C to about 35°C, from about 15°C to about 25°C, or from about 17°C to about 22°C, etc. In some embodiments, the emulsion polymerization mixture may include a soft ethylenically unsaturated monomer that, when homopolymerized, forms a polymer having a high glass transition temperature (as measured by ASTM D3418-15) of 80°C or more, 82°C or more, 85°C or more, 87°C or more, 90°C or more, 92°C or more, 95°C or less, 97°C or less, 100°C or less, 102°C or less, 105°C or less, or any value encompassed by these endpoints, as measured using DSC. For example, the first theoretical T g It can be from about 80°C to about 105°C, from about 85°C to about 95°C, or from about 87°C to about 92°C, etc.

[0036] The emulsion polymerization mixture may also contain hard ethylenically unsaturated monomers. Suitable hard ethylenically unsaturated monomers may include monomers having T g = 100°C styrene or methyl methacrylate (T g = 125°C).

[0037] Styrene or methyl methacrylate can be present in the composition in an amount of about 30 wt.% or greater, about 35 wt.% or greater, about 40 wt.% or less, about 45 wt.% or less, about 50 wt.% or less, or any value or range encompassed by these endpoints (e.g., 30 to 50 wt.%, or 35 to 45 wt.%), based on the total weight of the monomers used.

[0038] The emulsion polymerization mixture may further comprise one or more carboxylic acid-containing monomers, based on the total weight of the monomers. Suitable carboxylic acid-containing monomers are known in the art and include α,β-monoethylenically unsaturated monocarboxylic and dicarboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, dimethacrylic acid, ethacrylic acid, allyl acetic acid, vinyl acetic acid, mesaconic acid, methylenemalonic acid, citraconic acid, and combinations thereof.

[0039] In some embodiments, the emulsion polymerization mixture can be substantially free of styrene. In other words, the amount of styrene in the mixture can be 1 wt.% or less, 0.5 wt.% or less, 0.1 wt.% or less, or 0 wt.%, based on the total weight of the mixture.

[0040] In certain embodiments, the emulsion polymerization mixture can be substantially free of solid grade oligomer (SGO) resin. In other words, the amount of SGO in the mixture can be 5 wt.% or less, 3 wt.% or less, 1 wt.% or less, 0.1 wt.% or less, or 0 wt.% based on the total weight of the mixture.

[0041] In certain embodiments, the emulsion polymerization monomers may include styrene or a mixture of methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, and additional functional monomers such as acrylic acid, methacrylic acid, and / or itaconic acid.

[0042] In certain embodiments, the amount of styrene monomer present in the emulsion polymerization mixture, as a percentage of the total emulsion polymerization mixture, can be about 30 wt.% or greater, about 35 wt.% or greater, about 40 wt.% or greater, about 45 wt.% or greater, about 50 wt.% or greater, about 55 wt.% or greater, about 60 wt.% or less, about 65 wt.% or less, about 70 wt.% or less, about 75 wt.% or less, about 80 wt.% or less, about 85 wt.% or less, about 90 wt.% or less, about 95 wt.% or less, about 100 wt.% or less, or any value or range encompassed by these endpoints.

[0043] In certain embodiments, the amount of methyl methacrylate monomer present in the emulsion polymerization mixture, as a percentage of the total emulsion polymerization mixture, can be about 40 wt.% or greater, about 41 wt.% or greater, about 42 wt.% or greater, about 43 wt.% or greater, about 44 wt.% or greater, about 45 wt.% or greater, about 46 wt.% or less, about 47 wt.% or less, about 48 wt.% or less, about 49 wt.% or less, about 50 wt.% or less, or any value encompassed by these endpoints.

[0044] In certain embodiments, the amount of butyl acrylate monomer present in the emulsion polymerization mixture, as a percentage of the total emulsion polymerization mixture, can be about 30 wt.% or greater, about 31 wt.% or greater, about 32 wt.% or greater, about 33 wt.% or greater, about 34 wt.% or greater, about 35 wt.% or greater, about 36 wt.% or less, about 37 wt.% or less, about 38 wt.% or less, about 39 wt.% or less, about 40 wt.% or less, or any value encompassed by these endpoints.

[0045] In certain embodiments, the amount of 2-ethylhexyl acrylate monomer present in the emulsion polymerization mixture, as a percentage of the total emulsion polymerization mixture, can be about 10 wt.% or greater, 15 wt.% or greater, 20 wt.% or greater, 25 wt.% or greater, 30 wt.% or greater, about 35 wt.% or greater, about 40 wt.% or greater, about 45 wt.% or greater, about 50 wt.% or greater, about 55 wt.% or greater, about 60 wt.% or less, about 65 wt.% or less, about 70 wt.% or less, about 75 wt.% or less, about 80 wt.% or less, about 85 wt.% or less, about 90 wt.% or less, about 95 wt.% or less, about 100 wt.% or less, or any value or range encompassed by these endpoints.

[0046] In certain embodiments, the emulsion polymerization mixture may include one or more functional monomers. The functional monomers may include one or more of acrylic acid monomers, methacrylic acid monomers, and itaconic acid monomers. As a percentage of the total emulsion polymerization mixture, the functional monomer can be present at 0 wt.% or greater, about 0.1 wt.% or greater, about 0.2 wt.% or greater, about 0.3 wt.% or greater, about 0.4 wt.% or greater, about 0.5 wt.% or greater, about 0.6 wt.% or greater, about 0.7 wt.% or greater, about 0.8 wt.% or greater, about 0.9 wt.% or greater, about 1.0 wt.% or less, about 1.1 wt.% or less, about 1.2 wt.% or less, about 1.3 wt.% or less, about 1.4 wt.% or less, about 1.5 wt.% or less, about 1.6 wt.% or less, about 1.7 wt.% or less, about 1.8 wt.% or less, about 1.9 wt.% or less, about 2.0 wt.% or less, or about 3.0 wt.% or less. wt. % or less, or any value encompassed by these endpoints, is present in the emulsion polymerization mixture.

[0047] In certain embodiments, the emulsion polymerization mixture may also have modified starch added as a post-addition. After preparing the high-biorenewable polymer dispersion, approximately 5-20 wt.% of a modified or degraded starch solution (DE: 15%-40%) may be added to the dispersion as a post-addition. The addition of the modified starch increases the biorenewable content of the emulsion polymerization mixture.

[0048] In some embodiments, the emulsion polymerization mixture may further comprise co-stabilizers, such as polysaccharides, lignin sulfonates, and glycoside surfactants.

[0049] III. Ink and Overprint Varnish Compositions

[0050] Also provided are aqueous inks or overprint varnish compositions comprising one or more of the above-mentioned polymer emulsions. The aqueous composition may further comprise one or more additives, including pigments, fillers, dispersants, coalescing agents, defoamers, surfactants, thickeners, biocides, and combinations thereof. The selection of the additive in the composition may be influenced by many factors, including the properties of the polymers dispersed in the aqueous composition and the intended use of the composition. Although the compositions of the present invention are particularly suitable for use as adhesives in ink and overprint varnish formulations, they may also be used in other applications, including top coating agents, paints, adhesives, fillers, molding materials, electronic materials such as resists, etc., for plastics. In some cases, the composition may be, for example, a coating composition, including a coating composition that meets food safety. In certain embodiments, the composition comprises a volatile organic compound (VOC) that is less than or equal to 50 grams per liter.

[0051] The aqueous composition can comprise greater than 30% solids, such as about 30% or greater, 40% or greater, about 50% or greater, about 55% or greater, about 60% or greater, about 65% or greater, or about 70% or greater.

[0052] In some embodiments, the aqueous composition may further comprise one or more surfactants. Suitable surfactants may include, for example, Poly Step A16-22 (sodium dodecylbenzenesulfonate from Stephan), Disonil A1080, Calfax DB45, Aeorosol OT 75 (sodium dioctyl sulfosuccinate), Tergitol 15-S-9 (secondary alcohol ethoxylate from Dow Chemical), and combinations thereof.

[0053] The composition can include 0% by weight or greater (e.g., 0% by weight, at least 0.5% by weight, at least 1% by weight, at least 1.5% by weight, at least 2% by weight, at least 2.5% by weight, at least 3% by weight, at least 3.5% by weight, at least 4% by weight, at least 4.5% by weight, at least 5% by weight, at least 5.5% by weight, at least 6% by weight, at least 6.5% by weight, at least 7% by weight, at least 7.5% by weight, at least 8% by weight, at least 8.5% by weight, at least 9% by weight, or at least 9.5% by weight) of one or more surfactants, based on the total weight of all components of the aqueous composition. The composition can include 10% or less (e.g., 9.5% or less by weight, 8% or less by weight, 8.5% or less by weight, 8% or less by weight, 7.5% or less by weight, 7% or less by weight, 6.5% or less by weight, 6% or less by weight, 5.5% or less by weight, 5% or less by weight, 4.5% or less by weight, 4% or less by weight, 3.5% or less by weight, 3% or less by weight, 2.5% or less by weight, 2% or less by weight, 1.5% or less by weight, 1% or less by weight, or 0.5% or less by weight) of one or more surfactants, based on the total weight of all components of the aqueous composition.

[0054] The composition can include one or more surfactants in an amount ranging from any of the minimum percentages described above to any of the maximum percentages described above. For example, the composition can include 0% to 10% by weight of one or more surfactants (e.g., 0% to 3% by weight of one or more surfactants, 0% to 2.5% by weight of one or more surfactants, 0% to 1.5% by weight of one or more surfactants, or 0% to 1% by weight of one or more surfactants, based on the total weight of all components of the aqueous composition). In some embodiments, the composition is substantially free of (i.e., the composition includes 0.1% or less by weight of) surfactants.

[0055] The example of suitable pigment comprises metal oxide, such as titanium dioxide, zinc oxide, iron oxide or its combination.Said composition can also contain organic pigment, such as phthalocyanine, and it is as Sunfast® Blue 15:3,249-1283 available from Sun Chemical Company (Sun Chemical).Other examples comprise available phthalocyanine dispersion Flexiverse® BFD-1121, BFD-8153 and BFD-3153 from Sun Chemical Company.In certain embodiments, said composition comprises titanium dioxide pigment.The example of commercial titanium dioxide pigment is available KRONOS® 2101, KRONOS® 2310 from Kronos WorldWide, Inc. (Cranbury, NJ), available TI-PURE® R-900 from DuPont (Wilmington, Delaware), or commercially available TIONA® AT1 from Millenium Inorganic Chemicals. Titanium dioxide is also available in the form of concentrated dispersions. An example of a titanium dioxide dispersion is KRONOS® 4311, also available from KRONOS Global.

[0056] Examples of suitable fillers include calcium carbonate, nepheline syenite (25% nepheline, 55% sodium feldspar, and 20% potassium feldspar), feldspar (aluminosilicate), diatomaceous earth, fumed diatomaceous earth, talc (hydrated magnesium silicate), aluminosilicate, silica (silicon dioxide), alumina (aluminum oxide), clay (hydrated aluminum silicate), kaolin (kaolinite, hydrated aluminum silicate), mica (hydrated potassium aluminum silicate), pyrophyllite (aluminum silicate hydroxide), perlite, barite (barium sulfate), wollastonite (calcium metasilicate), and combinations thereof. In certain embodiments, the composition comprises a calcium carbonate filler.

[0057] Examples of suitable dispersants are polyacid dispersants and hydrophobic copolymer dispersants. Polyacid dispersants are typically polycarboxylic acids, such as polyacrylic acid or polymethacrylic acid, in the form of their ammonium salts, alkali metal salts, alkaline earth metal salts, ammonium salts, or lower alkyl quaternary ammonium salts, in part or in whole. Hydrophobic copolymer dispersants include copolymers of acrylic acid, methacrylic acid, or maleic acid with a hydrophobic monomer. In certain embodiments, the composition comprises a polyacrylic acid-based dispersant, such as pigment dispersant N commercially available from BASF SE.

[0058] Suitable coalescing agents that aid in film formation during drying include ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, and combinations thereof.

[0059] Examples of suitable thickeners include hydrophobically modified ethylene oxide urethane (HEUR) polymers, hydrophobically modified alkali-soluble emulsion (HASE) polymers, hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobically modified polyacrylamide, and combinations thereof. HEUR polymers are linear reaction products of diisocyanates and polyethylene oxide terminated with hydrophobic hydrocarbon groups. HASE polymers are homopolymers of (meth)acrylic acid or copolymers of (meth)acrylic acid, (meth)acrylates, or maleic acid modified with a hydrophobic vinyl monomer. HMHEC includes hydroxyethyl cellulose modified with a hydrophobic alkyl chain. Hydrophobically modified polyacrylamides include copolymers of acrylamide and acrylamide modified with a hydrophobic alkyl chain (N-alkylacrylamide). In certain embodiments, the coating composition includes a hydrophobically modified hydroxyethyl cellulose thickener.

[0060] Defoamers are used to minimize foaming during mixing and / or application of the coating composition. Suitable defoamers include silicone oil defoamers, such as polysiloxanes, polydimethylsiloxanes, polyether-modified polysiloxanes, and combinations thereof. Exemplary silicone-based defoamers include BYK®-035 available from BYK USA Inc. (Wallingford, Connecticut), the TEGO® series of defoamers available from Evonik Industries (Hopewell, Virginia), and the DREWPLUS® series of defoamers available from Ashland Inc. (Covington, Kentucky).

[0061] Suitable surfactants include nonionic surfactants and anionic surfactants. Examples of nonionic surfactants are alkylphenoxypolyethoxyethanols having an alkyl group with about 7 to about 18 carbon atoms and about 6 to about 60 oxyethylene units; ethylene oxide derivatives of long-chain carboxylic acids; similar ethylene oxide condensates of long-chain alcohols, and combinations thereof. Exemplary anionic surfactants include sulfosuccinates, higher fatty alcohol sulfates, aryl sulfonates, alkyl sulfonates, ammonium salts of alkylaryl sulfonates, alkali metal salts, alkaline earth metal salts, and lower alkyl quaternary ammonium salts, and combinations thereof. In certain embodiments, the composition comprises a nonionic alkyl polyethylene glycol surfactant, such as LUTENSOL® TDA 8 or LUTENSOL® AT-18, commercially available from BASF. In certain embodiments, the composition comprises an anionic alkyl ether sulfate surfactant. In certain embodiments, the composition comprises an anionic diphenyl oxide disulfonate surfactant, such as CALFAX® DB-45, commercially available from Pilot Chemical. In some embodiments, the composition comprises an anionic surfactant, such as Aeorosol OT75. In some embodiments, the composition is substantially free (i.e., the composition comprises 0.1% or less by weight) of sulfate surfactants. In some embodiments, the composition is substantially free (i.e., the composition comprises 0.1% or less by weight) of sulfonate surfactants. In some embodiments, the composition is substantially free (i.e., the composition comprises 0.1% or less by weight) of sulfate and sulfonate surfactants.

[0062] Suitable biocides may be incorporated to inhibit the growth of bacteria and other microorganisms in the coating composition during storage. Exemplary biocides include 2-[(hydroxymethyl)amino]ethanol, 2-[(hydroxymethyl)amino]2-methyl-1-propanol, o-phenylphenol, sodium salt, 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one (MIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CIT), 2-octyl-4-isothiazolin-3-one (OTT), 4,5-dichloro-2-n-octyl-3-isothiazolone, and acceptable salts and combinations thereof. Suitable biocides also include mildew inhibitors that inhibit the growth of mold or its spores in the coating. Examples of mildewcides include 2-(thiocyanatomethylthio)benzothiazole, 3-iodo-2-propynylbutylcarbamate, 2,4,5,6-tetrachloroisophthalonitrile, 2-(4-thiazolyl)benzimidazole, 2-N-octyl 4-isothiazolin-3-one, diiodomethyl-p-tolylsulfone, and acceptable salts and combinations thereof. In certain embodiments, the coating composition contains 1,2-benzisothiazolin-3-one or a salt thereof. This type of biocide includes PROXEL® BD20 commercially available from Arch Chemicals, Inc. (Atlanta, Georgia).

[0063] Other suitable additives that may optionally be incorporated into the composition include rheology modifiers, wetting and spreading agents, leveling agents, conductivity additives, adhesion promoters, anti-blocking, anti-cratering and anti-crawling agents, antifreeze agents, corrosion inhibitors, antistatic agents, flame retardants and swelling additives, dyes, optical brighteners and fluorescent additives, UV absorbers and light stabilizers, chelating agents, cleanability additives, crosslinking agents, matting agents, flocculants, humectants, insecticides, lubricants, odorants, oils, waxes and slip aids, anti-fouling agents, anti-stain agents, and combinations thereof.

[0064] The following examples are intended to further illustrate certain aspects of the methods and compositions described herein and are not intended to limit the scope of the claims.

[0065] Examples

[0066] The following examples are presented to provide one of ordinary skill in the art with a complete disclosure and description of how to make and evaluate the compositions and / or methods claimed herein, and are intended to be exemplary only and not intended to limit the scope of this disclosure. Unless otherwise indicated, parts are parts by weight, temperatures are in ° C or at ambient temperature, and pressures are at or near atmospheric pressure.

[0067] Procedure 1: Synthesis of polymer resin dispersion

[0068] Deionized water, rosin ester solution, defoamer (Dow Corning P1200), and surfactant (Polystep A16-22) were added to a reaction vessel equipped with a condenser, thermometer, nitrogen inlet, and overhead stirrer and heated to a temperature of 75-76°C under a nitrogen stream. At 75°C, the initiator (reducing agent) and catalyst were added. The monomers and surfactant (secondary alcohol ethoxylate or sodium dioctyl sulfosuccinate) and initiator (tert-butyl hydroperoxide) were fed in two separate feeds over 65 minutes, followed by a 30-minute post-polymerization period with stirring. Two chemical strips were then started simultaneously and continued for 60 minutes. After chemical strips 1 and 2 were completed, the post-polymerization mixture was added for 30 minutes. The reaction was cooled to room temperature. Acticide MV was added at 25°C, and the reaction was then filtered. The desired aqueous polymer resin dispersion was obtained and its properties, including solids content, pH, Brookfield viscosity, % coagulum, mictrotrac particle size, GC, and Tg, were measured.

[0069] The solids content of the dispersion was measured gravimetrically by drying about 0.5 g to about 2 g of a sample of the dispersion in an oven at 140° C. for 1 hour.

[0070] Viscosity was measured by Brookfield LV at 20°C to 25°C.

[0071] Particle size and volume average particle size were measured using a nano-flex particle size analyzer from Microtrac.

[0072] The coagulant was measured by filtering 1 kg of the dispersion with a 150 mesh filter and then measuring.

[0073] Glass transition temperature was measured by differential scanning calorimetry (DSC) according to ASTM D3418-15.

[0074] The polymer resin dispersions obtainable by Procedure 1 outlined above were formulated into hard film-forming adhesives and non-film-forming adhesives. The physical properties and application test data of these adhesives are provided in the following Examples.

[0075] Non-film-forming adhesives containing biorenewables

[0076] The physical properties of the non-film-forming biorenewable-containing adhesives are presented below in Table 1. In Table 1, SM = styrene, AA = acrylic acid, MMA = methyl methacrylate, nBA = n-butyl acrylate, EA: ethyl acrylate, IBA: isobutyl acrylate; BRC = biorenewable content.

[0077] Table 1

[0078]

[0079] The above binder emulsions were formulated into inks using the components listed in Table 2 below.

[0080] Table 2

[0081]

[0082] The inks prepared according to Table 2 above were then tested to determine their optical and physical properties. The results of these tests are summarized in the table below.

[0083] Tables 3 and 4 summarize the optical testing of the examples using a gloss meter.

[0084] Table 3

[0085]

[0086] Table 4

[0087]

[0088] The inks were also dry rub tested using a 4 pound sled. A total of 100 rubs were performed, and each example was rated at 50 rub intervals using the 1-10 rub rating system described in Table 5 below. In Table 5, SBS refers to solid bleached sulfate board. C1S is coated SBS board.

[0089] Table 5

[0090]

[0091] Table 6

[0092]

[0093] Table 7

[0094]

[0095] The ink was subjected to a water spot test using deionized water. The water spot test was performed at the following intervals: 30 seconds, 1 minute, and 2 minutes. Each example was evaluated using the 1-10 point rub rating system described in Table 8 below.

[0096] Table 8

[0097]

[0098] Table 9

[0099]

[0100] Table 10

[0101]

[0102] The ink was also tested for blocking using a B01 spring at 36.7 mm and 60 lbs of force. The samples were then aged at 50°C for 24 hours. Each example was evaluated using the 0-5 point blocking rating system described in Table 11 below, and the results of the blocking tests are presented in Tables 12 and 13.

[0103] Table 11

[0104]

[0105] Table 12

[0106]

[0107] Table 13

[0108]

[0109] The inks were tested for redissolubility using a 5" roller and a 30 second free run time and a 15 minute dry time in a Geiger press according to the following procedure.

[0110] Place ink on each side of a split plate on a Geiger proofer. Turn on the proofer and run a print to determine the baseline appearance of the ink. Then turn off the proofer. After shutting down, turn the proofer back on and run a print immediately, and then run a print every 30 seconds or 1 minute thereafter for up to 5 minutes while the anilox roller continues to rotate through the ink.

[0111] The roll was a 200Q segmented roll and the test was conducted at speed level 3. The results are summarized in Table 14 below.

[0112] Table 14

[0113]

[0114] Table 15

[0115]

[0116] Hard-film-forming adhesive containing biorenewables

[0117] The physical properties of the hard film-forming biorenewable-containing adhesive are presented in Table 16 below.

[0118] Table 16

[0119]

[0120] The above binder emulsions were formulated into inks using the components listed in Table 17 below.

[0121] Table 17

[0122]

[0123] The inks prepared according to Table 17 above were then tested to determine their optical and physical properties. The results of these tests are summarized in the table below. Table 18 summarizes the optical testing performed on the examples using a gloss meter.

[0124] Table 18

[0125]

[0126] The inks were also dry rub tested using a 4 pound sled at speed 2. A total of 100 rubs were performed, and each example was rated at 50 rub intervals using the 1-10 rub rating system previously described in Table 5. The results of the dry rub testing are summarized in Table 19 below.

[0127] Table 19

[0128]

[0129] The inks were also subjected to a water spot test using deionized water. This water test was performed at the following intervals: 30 seconds, 1 minute, and 2 minutes. Each example was evaluated using the 1-10 rub rating system previously described in Table 8. The results of the water spot test are shown in Table 20 below.

[0130] Table 20

[0131]

[0132] The ink was also tested for blocking using a B01 spring at 36.7 mm and 60 pounds of force. The samples were then aged at 50°C for 24 hours. Each example was evaluated using the 0-5 point blocking rating system previously described in Table 11. The results of the blocking tests are summarized in Table 21 below.

[0133] Table 21

[0134]

[0135] The inks were tested for redissolubility in a Geiger press using a 5" roller with a 30 second free run time and a 5 minute dry time. The roller was a 200Q segmented roller and the test was conducted at speed level 3. The results are summarized in Table 22 below.

[0136] Table 22

[0137]

[0138] Soft film-forming adhesive containing biorenewables

[0139] The formulations of soft film-forming adhesives 1S and 2S containing biorenewable monomers are presented below in Table 23. In Table 23, DW = deionized water; 2-EHA = 2-ethylhexyl acrylate; IBOMA = isobornyl methacrylate; Na-Ery = sodium erythorbate

[0140] Table 23

[0141]

[0142] A comparison of the soft film forming adhesives 1S and 2S with Joncryl 8052 is provided in Table 24 below.

[0143] Table 24

[0144]

[0145] The soft film-forming adhesives 1S and 2S containing biorenewable monomers were further formulated with rosin ester XR2780 in two ratios (w / w): 50 / 50 and 70 / 30. Details of the rosin ester (XR2780 from Lawter BV) formulations for 1S and 2S are provided in Table 25 below.

[0146] Table 25

[0147]

[0148] In Table 25 above, a 100% neutralized solution (30% non-volatile content) of Rosin Resin XR2780 from Lowtech was used.

[0149] The adhesive was formulated into flexographic / gravure inks for testing. The ink formulations are provided in Table 26 below.

[0150] Table 26

[0151]

[0152] A series of tests were performed on the ink formulations. These tests are detailed below.

[0153] Drawdown tests were performed on 50 µm (treated) white low-density polyethylene (LDPE) and / or treated biaxially oriented polypropylene (BOPP). A blue ink (viscosity + / - 20 sec. DIN 4) was applied using a 4 µm bar at a speed of 10. The substrates were oven-dried at 60°C for 20 seconds. For blocking tests and resolubility, a 6 µm bar was used.

[0154] Perform a heat seal peel test. Stack the drawdowns with the coated areas facing the pad side of the aluminum foil. Next, fold the aluminum foil so that the non-printed areas face each other. Seal the sample using a heat sealer with double-sided heat at a pressure of 450 N for 1.0 s. Observe the sample for damage and peeling. The sealing conditions for a 10 mm flat seal are as follows: Jaws: Flat seal 10 x 15 mm. Sealing temperature: 140°C - 160°C - 180°C.

[0155] Drawdown tests were also completed on corona-treated foil. Tape adhesion after 20 seconds at 60°C (H / FF 03-01). A pressure-sensitive adhesive tape was applied to the coated area. Adhesion was considered adequate if no coating was pulled off by the tape when the tape was removed. Scratch / abrasion resistance after 1 minute at 60°C. Scratch instructions: Scratch the foil 5 times with the tip of a fingernail. Abrasion instructions: Rub the foil 5 times with a flat fingernail. Wrinkling (wet). (H / FF 03-02): Wrinkle the foil 10 times between hands and observe for damage. Blocking. (H / FC 03-02): Place the untreated side of another foil on top of the dry drawdown sample. Place the drawdown sample in a blocking machine at 30°C and 5T pressure for 24 hours. Wet satra. (See H / FF 04-01). Place the substrate in tap water for 2 hours. Immerse the satra pad in tap water. Rub the drawdown sample 200 times with cotton. Observe for damage. 200 / 100 means 200 rubs with 0% ink coming off the substrate.

[0156] Ink tests were performed on both color and white. Color: Dilute the ink (if necessary) to a 19-20" DIN 4 using a 35:65 blend of PC HPD396 / water. Check viscosity stability after 1 day, 1 week, and 4 weeks. White: Dilute the ink (if necessary) to a 19-20" DIN 4 using a 40:60 blend of PC T750W / water. Check viscosity stability after 1 day, 1 week, and 4 weeks.

[0157] Fingertip resolubility was tested according to test method H / FF 06-02. For the neat adhesive, drawdown and gloss testing were performed. Drawdowns were performed using a 12 µm wire rod on a Leneta 2A gloss card, or a 6 µm wire rod on a Leneta N2A-2 card. The substrates were dried in an oven at 60°C for 1 minute. Gloss testing was performed by measuring gloss using a BYK-Gardner Microgloss Meter at 60°. This BYK-Gardner Microgloss Meter is a single-angle instrument for specific applications. A specific 60° gloss meter is designed for determining the gloss of paint coatings, plastics, paper, or similar materials. Light is directed onto the surface of the test specimen at a defined angle, and the reflected light is measured photoelectrically.

[0158] A summary of the results from the foregoing testing is described in Tables 27 and 28 below.

[0159] Table 27

[0160]

[0161] The film clarity in Table 27 is rated based on a visual test scale of 1-5, where 1 = very opaque and 5 = very clear. Note that Example 2S was not diluted to 150 mPa.s due to the very small amount of product.

[0162] Table 28

[0163]

[0164]

Claims

1. A high-biorenewable emulsion composition suitable for use as an adhesive, the emulsion composition comprising: (i) rosin esters; (ii) copolymerizable monomers and (iii) Water.

2. The emulsion composition according to claim 1, wherein The rosin ester is present in an amount of 60 wt. % or greater based on the total weight of the composition.

3. The emulsion composition according to claim 1, wherein The copolymerizable monomer includes isobutyl acrylate.

4. The emulsion composition according to claim 1, wherein The copolymerizable monomer includes ethyl acrylate.

5. The emulsion composition according to claim 1, wherein The copolymerizable monomer includes 2-octyl acrylate.

6. The emulsion composition according to claim 1, wherein The copolymerizable monomer includes lauryl methacrylate.

7. The emulsion composition according to claim 1, wherein The composition further comprises a co-stabilizer selected from the group consisting of: a polysaccharide, a lignin sulfonate, and a glycoside surfactant.

8. The emulsion composition according to claim 1, wherein The emulsion composition comprises less than 1 wt. % styrene based on the total weight of the composition.

9. The emulsion composition according to claim 1, wherein The emulsion composition comprises less than 1 wt. % of a solid grade oligomeric resin, based on the total weight of the composition.

10. A method for preparing a polymer emulsion containing high biorenewable content, the method comprising: (i) providing a resin dispersion comprising at least one resin in an aqueous solution; (ii) adding at least one initiator and a polymerization mixture to the resin dispersion, the polymerization mixture comprising at least one copolymerizable monomer; and (iii) preparing a polymer emulsion in water by free radical emulsion polymerization of the polymerization mixture, the resin dispersion and the initiator.

11. The method according to claim 10, wherein: The copolymerizable monomer includes isobutyl acrylate.

12. The method of claim 10, wherein: The copolymerizable monomer includes ethyl acrylate.

13. The method of claim 10, wherein: The copolymerizable monomer includes 2-octyl acrylate.

14. The method of claim 10, wherein: The copolymerizable monomer includes lauryl methacrylate.

15. The method of claim 8, wherein: The modified starch is post-added to the polymer emulsion.

16. A printing ink comprising the emulsion composition according to claim 1.

17. An overprint varnish comprising the emulsion composition according to claim 1.

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