HK1193625B - Waterborne polyurethane coating compositions - Google Patents

Description

Waterborne polyurethane coating compositions

Technical Field

The present invention relates to a one-component waterborne polyurethane coating composition and the use of the composition for coating a substrate.

Background

For example, glass substrates may be coated to provide decorative effects or to enhance substrate properties. For example, glass substrates may be coated to provide blast resistance, abrasion resistance, increased elasticity, and solvent resistance. For example, glass containers may benefit from a clear coating that provides mechanical protection to the exterior surface to help minimize mechanical damage, such as scratches or scratches caused during shipping, storage, filling operations, and distribution.

Disclosure of Invention

Embodiments disclosed in this specification relate to aqueous polyurethane coating compositions. The aqueous polyurethane coating composition includes a polyol resin, an aminoplast resin, and a polycarbonate-polyurethane resin.

In various embodiments, an aqueous polyurethane coating composition includes (a) a water-dilutable, hydroxyl-functional polyacrylic resin; (b) a water dilutable aminoplast resin; and (c) a water-dilutable polycarbonate-polyurethane resin. The water-dilutable, hydroxy-functional polyacrylic resins comprise the reaction product of (A1) an olefinically unsaturated, hydroxy-functional monomer; (A2) an ethylenically unsaturated monomer comprising an ionic group or a potentially ionic group; and (a3) an olefinically unsaturated monomer that does not include an ionic group, a potentially ionic group, or a hydroxyl group. The hydroxy-functional polyacrylic resin component (a) and the aminoplast resin (b) react at a temperature above ambient temperature to form crosslinks. The polycarbonate-polyurethane resin is non-functional.

It is to be understood that the invention disclosed and described in this specification is not limited to the embodiments summarized in the summary of the invention section.

Detailed Description

Throughout this specification, various embodiments are described and illustrated to provide an overall understanding of the structure, function, operation, manufacture, and use of the disclosed products and processes. It is to be understood that the various embodiments described and illustrated in this specification are non-limiting and non-exhaustive. The invention is thus not limited to the various non-limiting and non-exhaustive embodiments disclosed in this specification. Rather, the invention is defined only by the claims. The features and characteristics illustrated and/or described in connection with different embodiments may be combined with the features and characteristics of other embodiments. Such modifications and variations are intended to be included within the scope of the present description. Thus, the claims hereof may be amended to recite any features or characteristics explicitly or inherently described in this specification, or to recite any explicitly or inherently supported features or characteristics in this specification. Rather, the applicants are entitled to amend the claims to expressly exclude features or characteristics that may be present in the prior art. Accordingly, any such modifications comply with the requirements of 35u.s.c. § 112, and 35u.s.c. § 132 (a). In the present specification, the various embodiments disclosed and described may include, consist of, or consist essentially of the various functions and features described herein.

Unless otherwise indicated, any patent, publication, or other disclosure material identified herein is incorporated by reference in its entirety to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this specification. Accordingly, and to the extent necessary, the explicit disclosure set forth in this specification supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, (i.e., that is incorporated by reference herein, but which conflicts with existing definitions, discussions and other disclosure material set forth herein) is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Applicants reserve the right to modify the specification to expressly recite any subject matter, or portion thereof, incorporated by reference herein.

Reference throughout this specification to "various non-limiting embodiments," or the like, means that a particular feature or characteristic may be included in an embodiment. Thus, use of the term "in various non-limiting embodiments" or the like in this specification is not necessarily to refer to a general embodiment, and may refer to a different embodiment. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments. Thus, particular features or characteristics illustrated or described in connection with various embodiments may be combined, in whole or in part, with features or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of this specification. In this way, the various embodiments described in this specification are non-limiting and non-exhaustive.

In the present specification, unless otherwise indicated, all numerical parameters are understood to be preceded and modified in all instances by the term "about," where the numerical parameter has the inherent variation characteristic of the following measurement technique used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described in this specification should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Moreover, any numerical range recited in this specification is intended to include all sub-ranges subsumed within that range. For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the lowest recited value of 1 and the highest recited value of 10; that is, has a minimum value equal to or higher than 1 and a maximum value equal to or lower than 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, applicants reserve the right to modify the specification (including the claims) to expressly recite any sub-ranges subsumed within the ranges expressly recited in this specification. All such ranges are inherently described in this specification so that modifications explicitly recited in any such subranges comply with the requirements of U.S. patent Law, clause 112, clause 1 and clause 132, clause (a).

The articles "a", "an", and "the" as used herein are intended to include "at least one" or "one or more", unless otherwise indicated. Thus, the articles are used in this specification to refer to one or to more than one (i.e., "at least one") of the grammatical objects of the article. For example, "an ingredient" means one or more ingredients, and thus more than one ingredient may be considered and may be used in the practice of the described embodiments. Furthermore, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of use requires otherwise.

Various embodiments herein disclose and describe waterborne (i.e., aqueous) polyurethane coating compositions that exhibit properties beneficial to a substrate, such as a glass substrate. The aqueous polyurethane coating compositions disclosed herein provide cured coatings exhibiting reduced hardness, increased flexibility, increased impact resistance, good adhesion to substrates in harsh environments, increased abrasion resistance, and increased solvent resistance. Aqueous polyurethane coating compositions can provide properties that are beneficial to a substrate (e.g., a glass substrate). The aqueous polyurethane coating composition may be a single component composition without a blocking agent. The aqueous polyurethane coating composition may include an aminoplast crosslinking ingredient for thermal curing.

Single component coating compositions include pre-mixed compositions that have acceptable service life and storage stability and that can be applied to a substrate and cured under specific conditions, such as at elevated temperatures or under exposure to ultraviolet light. For example, the one-component system comprises a hydroxy-functional resin crosslinked with an alkoxylated aminoplast or a reversible end-blocked isocyanate. In contrast, two-component coating compositions comprise two separate and mutually reactive components, which are mixed immediately prior to application to a substrate. These individual components each contain ingredients that are reactive under ambient conditions and immediately begin to form a cured resin upon mixing. Thus, the two components are limited in service life and must remain separate until use.

U.S. patent No.4,280,944, incorporated herein by reference, describes aqueous polyether-based polyurethane dispersions that, by virtue of the free hydroxyl groups and blocked isocyanate groups contained, constitute a single component system that can be thermally cured. However, it would be advantageous to have a one-part aqueous polyurethane dispersion coating composition that does not contain a blocking agent and is thermally curable. The use of melamine as a crosslinking agent for crosslinking with hydroxy-functional polyacrylic polyurethane dispersions may be an alternative.

Reference EP-A519,074, incorporated in the present specification, discloses that an aqueous glass coating composition is applied as two coats, wherein the top coat contains three main components, an aqueous polyurethane dispersion, an aqueous epoxy resin and an aqueous melamine/formaldehyde resin. The polyurethane dispersion reaches its desired final properties only after addition of large amounts of the other two resins. Thus, the disclosed coating compositions are multi-component compositions, rather than single component compositions.

An aminoplast crosslinking ingredient, such as a melamine crosslinker, may be added to the waterborne polyurethane coating composition to provide a one-part thermally curable waterborne polyurethane coating composition that is free of blocking agents. In general, the addition of the aminoplast crosslinker component increases the hardness of the cured coating film. Because of this, the use of aminoplast crosslinking components can result in undesirable coating properties, such as increased brittleness, decreased impact resistance, and decreased abrasion resistance.

These effects can be particularly problematic for substrates, for example for glass materials, which can easily show mechanical surface damage on harder and brittle coating films on the substrate. Furthermore, harder and brittle coating films tend to show increased mechanical wear, wear and corrosion. However, the present inventors have found a one-component thermally curable aqueous polyurethane coating composition free of blocking agents, which contains an aminoplast crosslinking component and exhibits low hardness and high flexibility, high impact resistance and toughness, and high abrasion resistance.

The one-part thermally curable aqueous polyurethane coating compositions disclosed herein may include (a) a polyol resin; (b) an aminoplast resin; and (c) a polycarbonate-polyurethane resin. The term "polyurethane" as used herein means a polymeric or oligomeric material that includes urethane groups, urea groups, or both. In addition, the term "polyurethane" also means a polymer or oligomer resin or a crosslinked polymer network containing urethane groups, urea groups, or both. The term "polyol" as used herein means a compound comprising at least two unreacted hydroxyl groups. The polyol can be a monomer, polymer, and/or oligomer that includes at least two pendant and/or terminal hydroxyl groups.

In various non-limiting embodiments, the polyol resin component (a) of the aqueous polyurethane coating compositions disclosed herein may comprise a water-dilutable, hydroxyl-functional polyacrylic resin. The term "polyacrylic resin" as used herein is meant to include oligomeric or polymeric macromolecules of residues of ethylenically unsaturated monomers. The water-dilutable hydroxy-functional polyacrylic resins may include those containing hydroxyl groups; sulfonic acid groups and/or carboxyl groups; sulfonate and/or carboxylate groups; or oligomers or polymers of other ionic or potentially ionic ethylenically unsaturated monomers.

In various non-limiting embodiments, the polyol resin component (a) is a water-dilutable, hydroxyl-functional polyacrylic resin. The term "water-dilutable" as used herein means the solubility of a solution of molecules in water, or the dispersion in water as a dispersion, emulsion, suspension, colloid, sol, or the like, with or without additional dispersants, emulsifiers, surfactants, co-solvents, and the like. The term "hydroxy-functional" as used herein means a molecule containing at least one unreacted hydroxyl group.

In various non-limiting embodiments, the polyol resin component (a) of the aqueous polyurethane coating compositions disclosed herein may comprise a water-dilutable, hydroxyl-functional polyacrylic resin. The term "polyacrylic resin" as used herein is meant to include oligomeric or polymeric macromolecules of residues of ethylenically unsaturated monomers. The water-dilutable, hydroxyl-functional polyacrylic resins may include oligomers or polymers of ethylenically unsaturated monomers that contain hydroxyl groups; sulfonic acid groups and/or carboxyl groups; sulfonate and/or carboxylate groups; or other ionic or potentially ionic groups.

The water-dilutable, hydroxy-functional polyacrylic resins can be produced by copolymerizing (A1) an olefinically unsaturated, hydroxy-functional monomer; (A2) an ethylenically unsaturated monomer comprising an ionic group or a potentially ionic group; and (A3) other ethylenically unsaturated monomers. In various non-limiting embodiments, the copolymerization of components (a1) through (A3) is carried out with component (a2) in a potentially ionic form (e.g., including nonionic sulfonic or carboxylic groups) that is at least partially converted to an ionic form after copolymerization.

In various non-limiting embodiments, the ethylenically unsaturated hydroxy-functional monomer (a1) may include, for example, hydroxyalkyl esters of acrylic or methacrylic acid (e.g., including 2 to 4 carbon atoms in the hydroxyalkyl group), such as 2-hydroxyethyl (meth) acrylate, the isomerized hydroxypropyl (meth) acrylate formed by the addition of propylene oxide to (meth) acrylic acid, the isomerized hydroxybutyl (meth) acrylate; and any combination thereof.

In various non-limiting embodiments, the ethylenically unsaturated monomer containing an ionic group or potentially ionic group (a2) may include, for example, a carbonyl group or a sulfonic acid group. Suitable monomers (a2) include, for example, olefinically unsaturated monocarboxylic or dicarboxylic acids having a molecular weight of from 72 to 207, such as acrylic acid; methacrylic acid; maleic acid; itaconic acid; and any combination thereof. Suitable monomers (A2) also include, for example, olefinically unsaturated compounds containing sulfonic acid groups, such as 2-acrylamido-2-methylpropanesulfonic acid. Any mixture of ethylenically unsaturated monomers containing ionic or potentially ionic groups may also be used.

In various non-limiting embodiments, the other ethylenically unsaturated monomer (a3) may comprise, for example, an ethylenically unsaturated compound that does not contain ionic groups, potentially ionic groups, or hydroxyl groups. Suitable monomers (a3) include, for example, esters of acrylic or methacrylic acid having 1 to 18 or 1 to 8 carbon atoms in the alcohol radical, such as methyl (meth) acrylate; ethyl (meth) acrylate; isopropyl (meth) acrylate; n-propyl (meth) acrylate; n-butyl (meth) acrylate; 2-ethylhexyl (meth) acrylate; n-stearyl (meth) acrylate; and any combination thereof. Suitable monomers (a3) may also include, for example, styrene; alkyl substituted styrenes; propenyl benzene; acrylonitrile; methacrylonitrile; vinyl acetate; vinyl stearate; epoxy functional comonomers, such as glycidyl acrylate or glycidyl methacrylate; n-methoxy methacrylamide; (ii) methacrylamide; and any combination thereof.

The water-dilutable hydroxy-functional polyacrylic resins containing the polymerization products of components (a1) to (A3) can be produced using polymerization methods such as bulk polymerization using free radical initiators, solution polymerization, emulsion polymerization, suspension polymerization techniques. Suitable processes are described in references incorporated herein, such as U.S. patent 5,331,039.

The olefinically unsaturated hydroxy-functional monomer (a1) is used in sufficient amounts to give the desired number of hydroxyl groups, for example a hydroxyl group content of 0.5 to 8 wt.% or 1 to 5wt.%, based on the weight of the water-dilutable hydroxy-functional polyacrylic resin. For example, the hydroxy-functional monomer (a1) may be used in an amount of 3 to 75 weight percent or 6 to 47 weight percent, based on the total weight of monomers (a1) to (A3). In various non-limiting embodiments, the amount of hydroxy-functional monomer (a1) can be selected such that the resulting polyacrylic acid copolymer includes at least two hydroxy groups per macromolecule on a statistical average basis.

In various non-limiting embodiments, the ethylenically unsaturated monomer containing an ionic group or potentially ionic group (a2) can be incorporated into a macromolecule by covalent bonding to at least partially impart water-dilutability (e.g., water solubility or water dispersibility) to the water-dilutable, hydroxyl-functional polyacrylic resin to increase the hydrophilicity of the macromolecule. The amount of monomer (A2) used and the degree of deprotonation of unreacted sulfonic or carboxylic acid groups should be sufficient to prepare stable aqueous dispersions or solutions with or without additional emulsifiers, dispersants, co-solvents, and the like. For example, in various non-limiting embodiments, the monomer (a2) can be used in an amount of 0.3 to 30 weight percent or 1 to 20 weight percent, based on the total weight of (a1) to (A3).

Depending on the molecular weight of the polypropylene resin, its ionic or potentially ionic groups, and/or the presence of any emulsifiers, co-solvents, etc., the aqueous system comprising the polyacrylic resin may be a colloidal dispersion, a molecular solution, or a mixture of the two. In embodiments where a lower amount of monomer (a2) is used, an aqueous dispersion (colloid) is typically formed, but a small amount of polymer may be included in the aqueous solution. The increased amount of resin of the higher content of monomer (a2) formed an aqueous solution (and the decreased amount of resin was in the form of a colloidal dispersion). As the relative amount of monomer (a2) increases, more water-dilutable hydroxy-functional polyacrylic resin may dissolve into the aqueous solution.

The water-dilutable hydroxy-functional polyacrylic resins have an average molecular weight (weight average, measured using colloid permeation chromatography with polystyrene standards) of 500 to 100000 or 1000 to 50000; the hydroxyl number is 16.5 to 264mgKOH/g or 33 to 165 mgKOH/g; the acid number is from 5 to 125mgKOH/g (based on any acid or potential ionic groups, 25% to 100% of which are in the form of an ionic salt). The water-dilutable hydroxy-functional polyacrylic resins may be present in the form of aqueous solutions and/or dispersions having a solids content of from 5 to 90 wt.%, from 10 to 60 wt.%, from 10 to 50 wt.%, from 20 to 45wt.%, or from 20 to 40 wt.%; a viscosity at 23 ℃ of 10 to 100000mPa.s or 100 to 10000 mPa.s; and may have a pH of 5 to 10 or 6 to 9. The aqueous system containing the polyacrylic resin may be a colloidal dispersion, a molecular solution, or a mixture of both, depending on the molecular weight of the polyacrylic resin, the content of its ionic groups or potential ionic groups, and/or the presence of any emulsifiers, co-solvents, etc.

In various non-limiting embodiments, the polyol resin component (a) of the aqueous polyurethane coating compositions disclosed herein may include a water-dilutable, hydroxyl-functional acrylic resin, as described in references U.S. patent nos. 4,151,143; 4,888,383, respectively; 5,308,912, respectively; 5,331,039, respectively; 5,552,477, respectively; or 6,962,953.

In various non-limiting embodiments, the polyol resin component (a) of the aqueous polyurethane coating compositions disclosed herein may comprise a water-dilutable, hydroxyl-functional polyacrylic resin. Suitable water-dilutable hydroxy-functional polyacrylic resins are available from Bayer materials science, Inc. (Bayer Material science LLC, Pittsburgh, Pa., USA), Pittsburgh, PA, Pa., USA, under the trade name。

In various non-limiting embodiments, the aminoplast resin component (b) of the aqueous polyurethane coating compositions disclosed herein may be selected from the group consisting of: urea-based water-soluble resins and melamine-based water-soluble resins. The term "aminoplast resin" as used herein means a resin based on urea-formaldehyde or melamine-formaldehyde condensation products. Suitable aminoplast resins are available from Cytec surface specialties Inc (Smyrna, USA) under the trade name Smyrna, GA. The aminoplast resin includes functional groups, such as alkoxymethyl groups, which can react with hydroxyl groups at temperatures above ambient temperature. For example, aminoplast resins comprising alkoxymethyl groups may be predominantly thoseThe polyol resin is cross-linked and cured by transesterification between the hydroxyl groups on the polyol resin and the alkoxymethyl groups on the aminoplast resin.

The term "cured" as used herein means that an applied film of the composition is at least cured to the touch (set-to-touch) in the state of a liquid composition as defined by astm d5895-standard methods for evaluating drying or curing during film formation of organic coatings using a mechanical recorder, which is also incorporated herein by reference. The terms "cure" and "curing" as used herein mean the process by which an applied liquid composition is converted from a liquid state to a cured state. The terms "cured", "curing" and "curing" encompass drying processes of the composition via solvent evaporation and chemical crosslinking of the ingredients in the composition.

In various non-limiting embodiments, the aminoplast resin component (b) of the aqueous polyurethane coating compositions disclosed herein may comprise a urea-based resin, which includes urea-formaldehyde condensation products. Suitable urea-formaldehyde condensation products include, for example, urea-formaldehyde condensates that are non-etherified, partially-etherified, or fully-etherified with monohydric alcohols containing from 1 to 20 carbon atoms.

In various non-limiting embodiments, the aminoplast resin component (b) of the aqueous polyurethane coating composition may comprise a melamine-based resin, which includes a melamine-formaldehyde condensation product. Suitable melamine-formaldehyde condensation products include, for example, melamine-formaldehyde condensates that are non-etherified, partially-etherified, or fully-etherified with monohydric alcohols containing from 1 to 20 carbon atoms. In various non-limiting embodiments, the aminoplast resin component (b) may comprise monomeric, oligomeric, or polymeric melamine-formaldehyde resins, such as methylated melamine, ethylated melamine, propylated melamine, butylated melamine, and mixed alkylated melamines (e.g., methylated/butylated melamine).

In various non-limiting embodiments, the aminoplast resin component (b) may comprise a hydroxymethyl group, an alkoxymethyl group, or both. The general formula of alkoxymethyl is-CH₂OR¹Wherein R is¹May be a linear, cyclic or branched alkyl chain having 1 to 20 carbon atoms. In various non-limiting embodiments, the aminoplast resin component (b) may comprise a condensation product of melamine-formaldehyde containing oligo-, methylated-, and high-imino-and low-methylol-containing groups. For example, the aminoplast resin component (b) may comprise an oligomeric methylated melamine-formaldehyde condensation product comprising imino groups, methoxymethyl groups, and methylol groups.

In various non-limiting embodiments, the polycarbonate-polyurethane resin component (c) of the aqueous polyurethane coating compositions disclosed herein can comprise a water-dilutable polycarbonate-polyurethane resin. The term "polycarbonate-polyurethane resin" as used herein means an oligomeric or polymeric macromolecule that contains carbonate groups and at least one urethane or urea group. Suitable polycarbonate-polyurethane resins include aqueous dispersions of aliphatic polycarbonate-polyurethane resins available from Bayer materials science, Inc., Pittsburgh, PA, USA under the trademark "Bayer materials science

The water dilutable polycarbonate-polyurethane resin may comprise the reaction product of (B1) a polyisocyanate component, (B2) a polycarbonate polyol component, and (B3) an isocyanate-reactive component comprising an ionic group or potentially ionic group.

In various non-limiting embodiments, the polyisocyanate component (B1) may include monomeric organic diisocyanates of the formula R (NCO)₂Wherein R is an organic group. In various non-limiting embodiments, R represents a divalent aliphatic hydrocarbon group having 4 to 18 carbon atoms, a divalent cycloaliphatic hydrocarbon group having 5 to 15 carbon atoms, a divalent araliphatic hydrocarbon group having 7 to 15 carbon atomsA hydrocarbon group or a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms.

Examples of suitable monomeric diisocyanates include, for example, 1, 4-tetramethylene diisocyanate, 1, 6-hexamethylene diisocyanate, 1-methyl-2, 4(2,6) -diisocyanatocyclohexane, 2, 4-trimethyl-1, 6-hexamethylene diisocyanate, 2,4, 4-trimethyl-1, 6-hexamethylene diisocyanate, 1, 12-dodecamethylene diisocyanate, cyclohexane-1, 3-diisocyanate, cyclohexane-1, 4-diisocyanate, 1-isocyanato-2-isocyanatomethylcyclopentane, 1-isocyanato-3-isocyanatomethyl-3, 5, 5-trimethyl-cyclohexane (isophorone diisocyanate), bis- (4-isocyanatocyclohexyl) -methane, 1, 3-and 1, 4-bis- (isocyanatomethyl) -cyclohexane, bis- (4-isocyanatocyclohexyl) -methane, 2,4 '-diisocyanato-dicyclohexylmethane, bis- (4-isocyanato-3-methyl-cyclohexyl) -methane,. alpha.' -tetramethyl-1, 3-and/or-1, 4-xylylene diisocyanate, 1-isocyanato-1-methyl-4 (3) -isocyanatomethylcyclohexane, 2, 4-and/or 2, 6-hexahydro-tolylene diisocyanate (2, 6-hexahydro-tolylenediisocyanate), 1, 3-and/or 1, 4-phenylene diisocyanate, 2, 4-and/or 2, 6-toluene diisocyanate, 2' -, 2,4' -and/or 4,4' -diphenylmethane diisocyanate, naphthylene-1, 5-diisocyanate, and isomers of the above or combinations thereof.

In various non-limiting embodiments, the polyisocyanate component can include a monomeric isocyanate that includes three or more isocyanate groups, such as 4-isocyanatomethyl-1, 8-octamethylene diisocyanate. The polyisocyanate component may comprise a polyphenylpolymethylene polyisocyanate obtained by phosgenating an aniline/formaldehyde condensate. The polyisocyanate component can also include aromatic isocyanates having three or more isocyanate groups, such as 4,4',4 "-triphenylmethane triisocyanate.

The polyisocyanate component (B1) also includes adducts of diisocyanates and/or oligomers comprising urethane groups, urea groups, uretdione groups, uretonimine groups, isocyanurate groups, iminooxadiazine dione groups, oxadiazinetrione groups, carbodiimide groups, acylurea groups, biuret groups, and/or urethane groups. For example, the polyisocyanate component may include:

(1) isocyanurate group-containing polyisocyanates which may be prepared as described, for example, in DE-PS2,616,416, EP-OS3,765, EP-OS10,589, EP-OS47,452, U.S. Pat. No.4,288,586 and U.S. Pat. No.4,324,879, which are incorporated herein by reference;

(2) uretdione diisocyanates are prepared by oligomerizing the isocyanate groups of a partial diisocyanate in the presence of a suitable catalyst, which may be, for example, a trialkylphosphine catalyst, and may optionally be used in admixture with other isocyanates, particularly the isocyanurate group-containing polyisocyanates described in (1) above.

(3) Biuret group-containing polyisocyanates can be prepared by using coreactants such as water, tertiary alcohols, primary and secondary monoamines, primary and/or secondary diamines according to the methods described in the references U.S. Pat. Nos. 3,124,605, 3,358,010, 3,644,490, 3,862,973, 3,906,126, 3,903,127, 4,051,165, 4,147,714 and 4,220,749 incorporated herein;

(4) iminooxadiazinedione and, optionally, isocyanurate group-containing polyisocyanates can be prepared in the presence of fluorine-containing catalysts, as described in the reference DE-A19611849 incorporated in the present description.

(5) Polyisocyanates containing carbodiimide groups can be prepared by low-polymerizing diisocyanates in the presence of carbodiimidization catalysts, as described in the references DE-PS1,092,007, U.S. Pat. No. 3,152,162 and DE-OS2,504,400, DE-OS2,537,685 and DE-OS2,552,350, which are incorporated in the present specification; and

(6) an oxadiazinetrione group-containing polyisocyanate, such as the reaction product of two moles of diisocyanate and one mole of carbon dioxide.

The polyisocyanate component (B1) includes adducts and/or oligomers of diisocyanates having an average isocyanate group functionality of, for example, 2 to 6 or 2 to 4. The polyisocyanate molecules (B1) including adducts and oligomers of diisocyanates may have an average isocyanate (NCO) content of 5 to 30 wt.%, 10 to 25 wt.%, or 15 to 25 wt.%, based on the weight of the ingredients.

In various non-limiting embodiments, the polyisocyanate component (B1) may be a monomeric (cyclo) aliphatic diisocyanate, such as a diisocyanate selected from the group consisting of: 1, 6-Hexamethylene Diisocyanate (HDI); 1-isocyanato-3-isocyanatomethyl-3, 5, 5-trimethyl-cyclohexane (isophorone diisocyanate or IPDI); 4,4' -diisocyanatodicyclohexylmethane (H)₁₂MDI); 1-methyl-2, 4(2,6) -diisocyanatocyclohexane; the isomers described above; and combinations of any of the above. For example, in various non-limiting embodiments, H₁₂MDI may be used to prepare a composition comprising (c) a water-dilutable polycarbonate-polyurethane resin. In various non-limiting embodiments, the polyisocyanate component (B1) may include 50 to 100 weight percent of an aliphatic diisocyanate and 0 to 50 weight percent of other aliphatic polyisocyanates having a molecular weight between 140 and 1500, such as adducts and/or oligomers of diisocyanates.

In various non-limiting embodiments, the polyisocyanate component (B1) may comprise HDI, IPDI, H₁₂At least one of MDI, 1-methyl-2, 4(2,6) -diisocyanatocyclohexane, and/or diisocyanate adducts comprising the isocyanurate, uretdione, biuret, and/or iminooxadiazinedione groups described above.

In various non-limiting embodiments, the polycarbonate polyol component (B2) may include a polycondensation reaction product of a polyhydric alcohol and phosgene or a polycondensation reaction product of a polyhydric alcohol and a carbonic acid diester. Suitable polyhydric alcohols include, for example, diols such as 1, 3-propanediol, ethylene glycol, propylene glycol, 1, 4-propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, trimethylene pentanediol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, neopentyl glycol, 1, 8-octanediol, and any mixtures thereof. Suitable polyhydric alcohols also include, for example, trifunctional or multifunctional hydroxyl compounds such as glycerol, trimethylolpropane, trimethylolethane, hexanetriol isomers, pentaerythritol, and any mixtures thereof. Trifunctional or multifunctional hydroxyl compounds can be used to prepare polycarbonate polyols having a branched structure.

The polycarbonate polyol has an average hydroxyl functionality of 1 to 5 or any subrange therein, for example, 1 to 2, 1.5 to 2.5, 1.2 to 2.2, or 1.8 to 2.2. The polycarbonate polyol has an average molecular weight between 300 and 10000 or any subrange therein, and can be, for example, 300 to 5000, 1000 to 8000, 1000 to 6000, 2000 to 6000, 500 to 3000, or 1000 to 3000. The polycarbonate polyol may have an OH number of 25 to 350mgKOH/g of solid.

In various non-limiting embodiments, the isocyanate-reactive component (B3) includes ionic or potentially ionic groups that can promote hydrophilicity of a macromolecule by covalently bonding to the macromolecule to at least partially impart water dilutability (e.g., water solubility or water dispersibility) to the water-dilutable polycarbonate-polyurethane resin. The isocyanate reactive component (B3) may include at least one ionic or potentially ionic group, which may be cationic or anionic in nature. The isocyanate-reactive component (B3) may also include at least one isocyanate-reactive functional group, such as a hydroxyl group and/or an amine group. The isocyanate-reactive functional groups of the isocyanate-reactive component (B3) and the hydroxyl functional groups of the polycarbonate polyol component (B2) may react with the isocyanate functional groups of the polyisocyanate component (B1) to at least partially prepare a water-dilutable polycarbonate polyurethane resin.

The cationic and anionic isocyanate-reactive ingredients (B3) include compounds containing compounds such as sulfonium groups, ammonium groups, phosphonium groups, carboxylate groups, sulfonate groups, phosphonate groups, or corresponding nonionic acid groups (i.e., potentially ionic groups) which can be converted to these groups by deprotonation (i.e., salt formation).

Suitable isocyanate-reactive ingredients (B3) include, for example, monohydroxycarboxylic acids, dihydroxycarboxylic acids, monoaminocarboxylic acids, diaminocarboxylic acids, monohydroxysulfonic acids, di-hydroxysulfonic acids, mono-sulfamic acids, di-sulfamic acids, mono-hydroxyphosphonic acids, di-hydroxyphosphonic acids, mono-aminophosphonic acids, di-aminophosphonic acids, ionic salts thereof, and any combination thereof.

Suitable isocyanate-reactive ingredients (B3) include, for example, dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, N- (2-aminoethyl) -beta-alanine, ethylenediamine-propyl-or butyl-sulfonic acid, 1, 2-or 1, 3-propylenediamine-beta-ethylsulfonic acid, citric acid, glycolic acid, lactic acid, 2-aminoethylaminoethanesulfonic acid, glycine; alanine, taurine, lysine, 3, 5-diaminobenzoic acid, the adduct of isophorone diisocyanate (IPDI) and acrylic acid (see, for example, European patent No. 916,647) and the alkali metal and/or ammonium salts thereof, the adduct of sodium bisulfite with but-2-ene-1, 4-diol, polyether sulfonates, and propoxylated adducts of 2-butanediol and NaHSO3 (see, for example, German patent No. 2,446,440).

Likewise, suitable isocyanate-reactive ingredients (B3) include, for example, other 2, 2-bis (hydroxymethyl) alkane carboxylic acids such as dimethylolacetic acid and 2, 2-dimethylolpentanoic acid. Further suitable isocyanate reactive ingredients (B3) include Michael adducts of dihydroxysuccinic acid, acrylic acid and amines, such as isophorone diamine or hexamethylene diamine, or mixtures of acids thereof, and/or dimethylol propionic acid and/or hydroxy pivalic acid. Still further, suitable isocyanate-reactive ingredients (B3) include sulfonic acid diols, for example, optionally containing ether groups, such as compounds described in reference U.S. patent No.4,108,814, incorporated herein.

In various non-limiting embodiments, the water-dilutable polycarbonate-polyurethane resin includes the reaction product of ingredient (B1), (B2) and an isocyanate-reactive ingredient (B3) having a carboxyl or carboxylate group, a sulfonic acid or sulfonate group, and/or an ammonium group. The isocyanate-reactive component (B3) may be incorporated onto the water-dilutable polycarbonate-polyurethane resin macromolecule by performing urethanization and urethanization reactions between the isocyanate-reactive groups and the isocyanate groups of the polyisocyanate component (B1).

In various non-limiting embodiments, the optional isocyanate-reactive component (B4) may include, for example, a chain extender and/or a chain terminator. The chain extending and/or chain terminating component may comprise ionic or potentially ionic groups and at least one group reactive with isocyanate groups in an addition reaction. Examples of chain extending components may include, for example, methylene diamine (methylene diamine); ethylene diamine; propylene diamine; 1, 4-butanediamine; 1, 6-hexamethylenediamine; 2-methyl-1, 5-pentanediamine (Dytek-A from DuPont (DuPont)); 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane (isophoronediamine); piperazine; 1, 4-diaminocyclohexane; bis (4-aminocyclohexyl) methane; adipic acid dihydrazide; alkylene oxide diamine; dipropylamine diethylene glycol (dipropylamine ethylene glycol); n- (2-aminoethyl) -2-aminoethanesulfonic acid (or a salt thereof); n- (2-aminoethyl) -2-aminopropionic acid (or a salt thereof); and any combination thereof.

Examples of chain terminating components include, for example, compounds having the following structural formula:

wherein R is₁Can be a hydrogen atom or an alkyl group, optionally having a hydroxyl end, R₂May be an alkyl group, optionally having a hydroxyl end. Suitable chain terminating compounds include, for example, monoamines and monoalcohols. For example, but not limited thereto, methylamine; ethylamine; propylamine; butylamine; octylamine; laurylamine; stearyl amine; isononyl oxypropylamine; dimethylamine; diethylamine; dipropylamine; dibutylamine; n-methylaminopropylamine; diethyl (methyl) aminopropylamine; morpholine; piperidine; diethanolamine; and any combination thereof. Also suitable are chain-terminating alcohols, such as C₁-C₁₀Or higher alcohols including methanol, butanol, and mixtures thereof,Hexanol, 2-ethylhexanol, isodecanol, and the like, and mixtures thereof, as well as aminoalcohols, such as Aminomethylpropanol (AMP).

The water-dilutable polycarbonate-polyurethane resin is prepared by reacting the components (B1) to (B4) using the acetone method or a variant thereof. A description of suitable processes can be found, for example, in the references MethodenderOrganischen Chemie (methods of organic chemistry) incorporated in the present specification (Houben-Weyl, 4th edition, VolumeE20/Part2, p.1682, Georg Thieme Verlag, Stuttgart, 1987) (Houben-Weyl, 4th edition, Vol. E20, Part2, p.1682, Georg Thieme Verlag, Stuttgart, Germany).

Non-limiting examples of the acetone process are described below. In the first stage, the adduct containing unreacted isocyanate groups is synthesized from a polyisocyanate component (B1), a polycarbonate polyol component (B2), and an isocyanate-reactive component containing ionic groups or potentially ionic groups (B3). In the second stage, the adduct is dissolved in an organic, at least partially water-miscible solvent, which does not contain isocyanate-reactive functional groups. Suitable solvents include acetone; methyl Ethyl Ketone (MEK); 2-butanone; tetrahydrofuran; dioxins, and any combinations thereof. In a third stage, the unreacted isocyanate-containing adduct solution is reacted with a mixture of amino-functional chain extenders and/or chain terminators. The amino-functional chain extender may contain sulfonic acid groups or carboxylic acid groups (which may be in the form of a non-ionic acid or in the form of an ionic salt). In the fourth stage, the water-dilutable polycarbonate-polyurethane resin product is dispersed by adding water to the organic solution or adding the organic solution to water to form a fine particle dispersion form. In the fifth stage, the organic solvent can be removed partly or completely by distillation, optionally under reduced pressure.

The water-dilutable polycarbonate-polyurethane resin may be characterized by a glass transition temperature between-60 ℃ and 0 ℃, for example between-40 ℃ and-20 ℃. The viscosity of the dispersion of the water-dilutable polycarbonate-polyurethane resin is below 1000 mPas or below 500 mPas at 25 ℃, for example between 50 and 1000 mPas or between 50 and 500 mPas. The water-dilutable polycarbonate-polyurethane resin has a number average molecular weight of 500 to 6000.

In various non-limiting embodiments, the one-part thermally curable aqueous polyurethane coating compositions disclosed herein may be applied to a substrate by way of a polyol resin component (a); an aminoplast resin component (b) and a polycarbonate-polyurethane resin component (c) are blended. The polyol resin component (a) and the aminoplast resin component (b) are used in amounts such that the equivalent ratio of alkoxymethyl groups of the aminoplast resin component (b) to hydroxyl groups of the polyol resin (a) is at least 0.05:1, such as from 0.05:1 to 20: 1.

in various non-limiting embodiments, the polycarbonate-polyurethane resin component (c) is non-functional. The term "non-functional" as used herein in relation to chemical components in the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein means substantially lacking chemical reactivity with the polyol resin component (a) and the aminoplast resin component (b). For example, non-functional polycarbonate-polyurethane resin component (c) does not chemically react with components (a) and/or (b) of the coating composition during thermal curing. In this manner, the non-functional polycarbonate-polyurethane resin component (c) is substantially free of unreacted isocyanate groups, unreacted hydroxyl groups, isocyanate-reactive groups, hydroxyl-reactive groups, and other functional groups that can react with any of the functional groups comprising the polyol resin component (a) and the aminoplast resin component (b).

The one-part thermally curable aqueous polyurethane coating compositions disclosed herein can be prepared by blending a water-dilutable polyol resin component (a), a water-dilutable aminoplast resin (b), and a water-dilutable polycarbonate-polyurethane resin component (c). These ingredients may be admixed in the aqueous dispersion, in the aqueous solution or in a combination of the aqueous dispersion and the aqueous solution, optionally with the addition of emulsifiers, dispersants, surfactants, co-solvents and/or the like. For example, the water-dilutable polyol resin component (a), the water-dilutable aminoplast resin component (b), and the water-dilutable polycarbonate-polyurethane resin component (c) may be provided in respective aqueous dispersions, aqueous solutions, and/or dispersions/solutions in water-miscible solvents, which may be combined together to form an aqueous mixture of components (a), (b), and (c). It is also possible to combine components (a), (b) and/or (c) in anhydrous form or to provide them as a solution/dispersion in a non-aqueous, water-miscible solvent, followed by dispersing a mixture of components (a), (b) and (c) in water.

A one-part thermally curable aqueous polyurethane coating composition includes a polyol resin component (a); an aminoplast resin component (b); and a polycarbonate-polyurethane resin component (c), characterized by a blended binder, wherein upon curing to crosslink the resin, components (a) and (b) react with each other, but component (c) is non-functional (i.e., non-reactive) with respect to components (a) and (b), thereby forming a non-crosslinked polymer network that interdigitates with the crosslinked polymer network comprising the reaction product of components (a) and (b).

In various non-limiting embodiments, the one-part thermally curable aqueous polyurethane coating compositions disclosed herein may comprise, on a solids basis, from 1% to 99%, preferably from 40% to 90%, and most preferably from 60% to 80%, of a water-dilutable, hydroxy-functional polyacrylic resin, and a water-dilutable aminoplast resin; and 99 to 1 wt% of a water-dilutable non-functional polycarbonate-polyurethane resin, preferably 60 to 10 wt%, most preferably 40 to 20 wt%, based on solids.

In various non-limiting embodiments, the weight ratio of the solids content of the polyol resin component (a) to the aminoplast resin component (b) can be from 55:45 to 85: 15. In various non-limiting embodiments, the weight ratio of the polyol resin component (a) to the aminoplast resin component (b) is from 60:40 to 70:30 on a solids basis.

In various non-limiting embodiments, a polyol resin component (a); an aminoplast resin component (b); and a polycarbonate-polyurethane resin component (c), may include optional ingredients such as additional polymeric polyol-based water-dilutable resin components. Additional water-dilutable polyester polyol-based resin components include, for example, polyether polyols, polyester polyols, polyepoxide polyols, polylactone polyols, polyacrylate polyols, polycarbonate polyols, and any combination thereof. The additional water-dilutable resin component can be formulated in aqueous solution and/or dispersion premixed with the resin components (a), (b) and (c).

In various non-limiting embodiments, a polyol resin component (a); an aminoplast resin component (b); and polycarbonate-polyurethane resin component (c) can be dry cured and/or thermally cured by any suitable technique known to those skilled in the art, such as air drying, accelerated drying upon exposure to heat, and thermal curing upon exposure to heat. For example, in various non-limiting embodiments, a polyol resin component (a); an aminoplast resin component (b); and a polycarbonate-polyurethane resin component (c), can be thermally cured by exposure to a temperature of 100 ℃ to 250 ℃ for 15 minutes to 60 minutes. The energy required to cure the system can be from any source known to those skilled in the art including, but not limited to, conventional convection ovens, infrared heat sources, microwaves, electron beams, or combinations thereof.

The one-component heat-curable aqueous polyurethane coating composition disclosed herein can prepare a cured coating film exhibiting a microhardness value of not more than 90N/mm²(horse (Martens)/Universal (Universal) hardness). In various non-limiting embodiments, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein can produce cured coating films that exhibit microhardness values of no greater than 75N/mm²、65N/mm²、55N/mm²、50N/mm²、45N/mm²、35N/mm²、25N/mm²、20N/mm²Or 15N/mm²。

In various non-limiting embodiments, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein can produce cured coating films that exhibit impact strength values of at least 20in-lbs (measured directly and/or inversely, in astm d 2794-93 (2010): standard test method for organic coating resistance to rapid deformation (impact) effect) (impact), which is incorporated herein by reference). In various non-limiting embodiments, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein can produce cured coating films that exhibit impact strengths of at least 120in-lbs, 140in-lbs, or 160 in-lbs.

In various non-limiting embodiments, the one-part thermally curable aqueous polyurethane coating compositions disclosed herein may also contain a silane-functional adhesion promoter, such as the adhesion promoter described in U.S. patent No. 6,403,175, the reference being incorporated herein by reference. Suitable adhesion promoters include, for example, gamma-mercaptopropyltrimethoxysilane; 3-aminopropyltriethoxysilane; 3-aminopropylsilane hydrolysate; 3-glycidyloxypropyltriethoxysilane; and any combination thereof.

The one-part thermally curable aqueous polyurethane coating compositions disclosed herein may be applied to a substrate using any suitable method, such as spraying; knife coating; curtain coating; vacuum coating; rolling; pouring; dipping; spin coating; brushing; brushing; spraying; screen printing; intaglio printing; flexographic printing or lithographic printing. Suitable substrates include, for example, glass; wood; a metal; paper; leather; a textile; a blanket; concrete; masonry; a ceramic; stone and plastics, for example moldings and films of ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE, UHMWPE, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM, SMC, BMC, PP-EPDM and UP (abbreviation according to DIN7728T 1). The one-part thermally curable aqueous polyurethane coating compositions disclosed herein may be applied to a substrate comprising a combination of the above materials. The one-part thermally curable aqueous polyurethane coating compositions disclosed herein may be used as a primer or topcoat prior to other coatings. The one-component thermally-curable aqueous polyurethane coating compositions disclosed herein may be applied to a temporary substrate support, partially or fully dried and/or cured, and released from the substrate support to prepare a free film, for example.

In various non-limiting embodiments, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein are particularly suitable for use on glass substrates, such as flat glass, glass panels, and glass containers, such as glass jars or bottles. Furthermore, the one-component thermally curable aqueous polyurethane coating compositions disclosed herein may provide abrasion resistance as well as durability, for example, advantageous during filling operations of glass containers. Glass substrates comprising the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein are characterized by good hand. The one-component thermally-curable aqueous polyurethane coating compositions disclosed herein can be applied to a glass substrate with or without hot end spray, with or without cold end spray, or both; and may or may not have a silane pretreatment of the glass substrate.

The one-component thermally curable aqueous polyurethane coating compositions disclosed herein can provide design freedom to produce transparent, tinted, high gloss, matte, and frosted appearances on glass substrates. Suitable representative pigments that may be formulated into the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein include, for example, rutile and anatase titanium dioxide, yellow and red iron oxides, green and blue copper phthalocyanine, carbon black, leafing (leafing) and non-leafing (nonleafing) aluminum, barium sulfate, calcium carbonate, sodium silicate, magnesium silicate, zinc oxide, antimony oxide, di-arylide yellow (di-arylide yellow), monoarylide yellow (monoarylide yellow), nickel arylide yellow, benzimidazolone orange, naphthol red, quinacridone red, pearlescent pigments (e.g., mica platelets), bronze platelets, nickel platelets, stainless steel platelets, micronized matting agents (e.g., methylene diamino methyl ether-polycondensates), and any combination thereof.

The one-component thermally-curable aqueous polyurethane coating compositions disclosed herein may be applied on labels (e.g., pressure sensitive labels, UV-activated labels, heat transfer labels, etc.) or on decorative organic and/or inorganic coatings that have been previously applied to glass substrates. Suitable decorative organic coatings that may be used with the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein include, for example, ecobrite organic ink (PPGIndustries, inc., Pittsburgh, PA, USA) (PPG industries, Pittsburgh, PA, USA), and SpecTruLite (Ferro corporation, Cleveland, OH, USA) (Ferro corporation, creverland, OH, USA).

The glass substrate is primed prior to application of the one-component thermally curable aqueous polyurethane coating compositions disclosed herein. The primer treatment may be any coating that provides lubrication to protect the glass substrate during manufacture and when the coating is applied and/or improves adhesion between the coating and the glass substrate. The primer treatment may include hot end spraying and cold end spraying. The glass substrate may not have a hot end spray so that a primer treatment including a cold end spray is applied after the substrate has substantially cooled. The primer treatment may comprise a cold end spray comprising a diluted silane composition or a mixture of a silane composition and a surface treatment composition. Any silane composition suitable for use as a primer on a glass substrate may be used for the primer coating, non-limiting examples of which include monoalkoxysilanes, dialkoxysilanes, trialkoxysilanes, and tetraalkoxysilanes.

The surface treatment composition may comprise a polyethylene composition, a stearic acid composition, or a mixture thereof, wherein removal is not required prior to applying a further coating on the glass substrate. Stearic acid compositions may include salts and esters of stearic acid (octadecanoic acid), such as T5 stearic acid coating (Tegoglas, Arkema, philiadelphia, PA, USA) (Tegoglas corporation, Arkema, Philadelphia, PA, USA). The primer coating may be in the form of an aqueous solution, dispersion or emulsion. For example, the surface treatment composition may include a polyethylene emulsion, such as Duracote, sun chemical (sun chemical). The primer treatment also includes additional compositions to improve the subsequently applied coating, non-limiting examples being surfactants and lubricants.

In various non-limiting embodiments, the one-component thermally curable aqueous polyurethane coating compositions disclosed herein can be used as primer coatings as well as topcoats, providing sufficient lubricity, abrasion resistance, and toughness for linear processing in glass containers.

The following non-limiting and non-exhaustive examples further describe various non-limiting and non-exhaustive embodiments without limiting the scope of the embodiments described in this specification. In the following examples, all parts and percentages are by weight unless otherwise indicated.

Examples

A one-part thermally curable aqueous polyurethane coating composition containing a polyacrylic polyol resin, an aminoplast resin, and a polycarbonate-polyurethane resin was prepared as follows. Aqueous dispersions of hydroxy-functional polyacrylic resinsAXP2770, Bayer materials science, Inc. (Bayer Material sciences LLC) (Pittsburgh, PA, USA, PA))) andandXP2637 was mixed.AXP2770 is provided in the form of an aqueous dispersion of a polyacrylic resin having a solids content of about 45wt.% and a hydroxyl content of 3.9wt.% on a solids basis.

Dipropylene glycol, gamma-mercaptopropyltrimethoxysilaneA-189, MomentivePerformance materials, Albany, NY, USA) (instantaneous Performance materials Inc. of Albany, NY, USA) and 3-aminopropyl-triethoxysilaneAMEO, evonik corporation, Parsippany, NJ, USA) (the knowley corporation of Parsippany, NJ, USA) was added to this aqueous mixture of hydroxy-functional poly (acrylic) resin, aminoplast resin, and polycarbonate-polyurethane resin with continuous stirring. The resulting mixture was stirred using a mechanical mixer until a homogeneous mixture was obtained. The homogeneous mixture was degassed and stored overnight before use. Mixtures (parts by weight, including solvent weight) were prepared according to the formulations listed in table 1.

The one-component thermally curable aqueous polyurethane coating compositions were tested for impact resistance, microhardness, and adhesion. The impact resistance test of the coating was performed on a Bonderite B1000 cold rolled steel panel using a number 50 wire wound rod. Microhardness testing of the coatings was performed on glass discs using an Eppendorf pipette (80 microliters) and spreading it on the discs using a pipette. The adhesion test of the coating was performed on the air end of a 4x4 inch glass Taber board using a number 50 wound wire rod.

The applied coating was cured in an oven at 170 ℃ for 30 minutes. The coatings for microhardness testing applied to the glass disks were left in dry air at ambient conditions for about 120 minutes before oven curing. All tests were performed at least after 24 hours after the applied coating and the substrate was removed from the oven. The film thickness of the cured coating on the steel panel was measured using a Fischer scoMaS instrument according to ASTM D1186-93, Standard test methods for non-destructive measurement of the dry film thickness of non-magnetic coatings applied on iron substrates, and is incorporated herein by reference. The film thickness ranges from 0.75 to 2.25 mils.

The impact resistance test is carried out according to ASTM D2794-93 (2010) Standard method for resistance of organic coatings to the effects of Rapid deformation (impact), which is incorporated herein by reference. Microhardness (horse/universal hardness) testing was performed on a fischer scope h100C instrument. The adhesion test is carried out according to ASTM D4060-95 Standard test method for abrasion resistance of organic coatings using a Taber grinder, which is incorporated herein by reference. The scratch adhesion test was performed on glass Taber plates. Two 1 inch long diagonal scribes were made to each other using a utility knife and the film adhesion on the glass was visually inspected. If no film is peeled from the substrate, this coating is indicated as "pass through".

The results of the impact resistance test, microhardness test, and scratch adhesion test are shown in table 1. The addition of the non-functional polycarbonate-polyurethane resin may improve its flexibility as well as the toughness of the coating, as shown by a decrease in microhardness and/or an increase in direct impact strength and/or an increase in reverse impact strength. Furthermore, the addition of non-functional polycarbonate-polyurethane resins does not have a negative effect on the adhesion. For example, formulations A, C and H did not contain any polycarbonate-polyurethane resin, but formulations B, D and I contained about 25% polycarbonate-polyurethane resin dispersion (10 wt% on solids) relative to formulations A, C and H, respectively. Comparing formulations A and B, formulations C and D, and formulations H and I, it was shown that the addition of non-functional polycarbonate-polyurethane resins generally results in a decrease in cured film hardness and an increase in impact strength.

Further, the weight ratios of the hydroxy-functional acrylic resin and the aminoplast resin in formulations C, D, E, F and G were the same. Formulations C contained no non-functional polycarbonate-polyurethane resin, and formulations D through G had increased non-functional polycarbonate-polyurethane resin content, i.e., 12% dispersion (5% solids), 25% dispersion (10% solids), 40% dispersion (16% solids), and 60% dispersion (24% solids). Comparing formulations C with formulations D through G, it was shown that as the amount of non-functional polycarbonate-polyurethane resin was increased, the hardness decreased while the impact strength and toughness increased and good substrate adhesion was maintained.

As described in the examples above, the one-component thermally curable aqueous polyurethane coating compositions disclosed herein exhibit low hardness, high impact resistance, high toughness, high abrasion resistance, good adhesion to glass substrates when free of blocking agents and include aminoplast resins. These results are significant and unexpected because, in general, when aminoplast resins are used to crosslink the polyol resins, harder cured coating films are produced. Thus, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein facilitate the use of aminoplast resins without resulting in adverse coating properties, such as increased brittleness, decreased impact resistance, and toughness. Thus, the one-component thermally curable aqueous polyurethane coating compositions disclosed herein are particularly advantageous for substrates, such as glass materials, on which mechanical surface damage of harder and brittle coating films can be readily manifested.

In various non-limiting embodiments, the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein can be used to coat glass containers, such as glass bottles and glass jars. The improved coating properties exhibited by the one-component thermally-curable aqueous polyurethane coating compositions disclosed herein (e.g., low hardness, high impact resistance, high toughness, good adhesion to glass substrates), which containers may experience significant scratching and/or marring when operated in machine line and subjected to line pressure, are particularly advantageous for glass container production operations. The one-component thermally-curable aqueous polyurethane coating compositions disclosed herein provide a surface coating that can withstand and absorb impact pressures during linear operation to minimize or eliminate surface scratching or marring.

This description has been written with reference to various non-limiting and non-exhaustive embodiments. However, those skilled in the art will recognize that various substitutions, modifications, or combinations of any of the disclosed embodiments (or portions thereof) may be made within the scope of the present description. Accordingly, it is contemplated and understood that additional embodiments of the present invention not explicitly set forth herein are supported in the present description. Such embodiments may be obtained by, for example, combining, modifying or recombining the steps, components, features, aspects, features, limitations, and the like, disclosed in any of the various non-limiting embodiments described in this specification. In this manner, the applicant has the right to amend during the application process to add new features as variously described in the present specification and to comply with 35u.s.c. § 112, first term, and 35u.s.c. § 132 (a).

Claims (20)

1. An aqueous polyurethane coating composition comprising:

(a) a water-dilutable, hydroxyl-functional polyacrylic resin comprising the reaction product of:

(A1) an ethylenically unsaturated hydroxy-functional monomer;

(A2) an ethylenically unsaturated monomer comprising an ionic group or a potentially ionic group; and

(A3) an ethylenically unsaturated monomer that does not include an ionic group, a potentially ionic group, or a hydroxyl group;

(b) a water-dilutable aminoplast resin; and

(c) a water-dilutable polycarbonate-polyurethane resin,

wherein the polycarbonate-polyurethane resin is non-functional.

2. The aqueous polyurethane coating composition according to claim 1, wherein the weight average molecular weight of the hydroxyl-functional polyacrylic resin component (a) is 500-100000, the number of hydroxyl groups is 16.5 to 264mgKOH/g, and the number of acids is 5 to 125 mgKOH/g.

3. The aqueous polyurethane coating composition of claim 1, wherein the aminoplast resin component (b) comprises a melamine-formaldehyde condensation product.

4. The aqueous polyurethane coating composition of claim 1, wherein the aminoplast resin component (b) comprises an oligomeric methylated melamine-formaldehyde condensation product containing imino groups, methoxymethyl groups, and methylol groups.

5. The aqueous polyurethane coating composition of claim 4, wherein the equivalent ratio of hydroxymethyl and methoxymethyl groups of component (b) to hydroxyl groups of component (a) is at least 0.05: 1.

6. The aqueous polyurethane coating composition of claim 1, wherein the polycarbonate-polyurethane resin component (c) comprises a polycarbonate polyol, the reaction product of a polyisocyanate and an isocyanate-reactive component comprising an ionic group or potentially ionic group, the polyisocyanate being selected from the group consisting of: 4,4' -diisocyanatodicyclohexylmethane, isophorone diisocyanate, 1, 6-hexamethylene diisocyanate, and 1-methyl-2, 4(2,6) -diisocyanatocyclohexane.

7. The aqueous polyurethane coating composition of claim 6, wherein the polycarbonate polyol has a number average molecular weight of 500 to 6000.

8. The aqueous polyurethane coating composition of claim 1, wherein the polycarbonate-polyurethane resin component (c) is characterized by a glass transition temperature between-60 ℃ and 0 ℃.

9. The aqueous polyurethane coating composition according to claim 1, wherein the polycarbonate-polyurethane resin component (c) is characterized by a viscosity of less than 500 mPa-s at 25 ℃ in 38% to 42% aqueous solid dispersion.

10. The aqueous polyurethane coating composition of claim 1, comprising:

99 to 1% by weight, calculated as solids, of a water-dilutable hydroxy-functional polyacrylic resin and a water-dilutable aminoplast resin; and

1 to 99% by weight, calculated as solids, of a water-dilutable polycarbonate-polyurethane resin,

wherein the sum of the weight percentages is 100 weight percent.

11. The aqueous polyurethane coating composition of claim 10, comprising:

40 to 90% by weight, calculated as solids, of a water-dilutable hydroxy-functional polyacrylic resin and a water-dilutable aminoplast resin; and

60 to 10% by weight, calculated as solids, of a water-dilutable polycarbonate-polyurethane resin,

wherein the sum of the weight percentages is 100 weight percent.

12. The aqueous polyurethane coating composition of claim 1, wherein the weight ratio of the hydroxy-functional polyacrylic resin to aminoplast resin is from 55:45 to 85:15 on a solids basis.

13. The aqueous polyurethane coating composition of claim 12, wherein the weight ratio of the hydroxy-functional polyacrylic resin to aminoplast resin is from 60:40 to 70:30 on a solids basis.

14. The aqueous polyurethane coating composition of claim 1, further comprising a silane functional adhesion promoter.

15. The aqueous polyurethane coating composition of claim 14, wherein the adhesion promoter is selected from the group consisting of: gamma-mercaptopropyltrimethoxysilane; 3-aminopropyltriethoxysilane; 3-aminopropylsilane hydrolysate; 3-glycidyloxypropyltriethoxysilane; and any combination thereof.

16. The aqueous polyurethane coating composition of claim 1, further comprising an additional polyol resin selected from the group consisting of: water-dispersible hydroxy-functional polyester resins and water-dispersible hydroxy-functional polyether-polyurethane resins.

17. A substrate at least partially coated with the coating composition of claim 1.

18. The substrate of claim 17, wherein the coating exhibits no greater than 90N/mm²A direct impact strength of at least 60in-lbs and a reverse impact strength of at least 20 in-lbs.

19. A glass substrate at least partially coated with the coating composition of claim 1.

20. A glass container at least partially coated with the coating composition of claim 1.