Aqueous composition

Abstract

The present invention relates to an aqueous composition comprising: (a) an acrylic copolymer comprising structural units of an ethylenically unsaturated acetoacetyl functional monomer and (b) a specific polyhydroxy functional amine, which can provide good formaldehyde scavenging properties and reduced yellowing.

Description

Technical Field

[0001] This invention relates to aqueous compositions comprising acetoacetyl-functionalized acrylic copolymers and polyhydroxy-functionalized amines. Background Technology

[0002] Aqueous polymer dispersions (also known as water-based polymer dispersions) are becoming increasingly important than solvent-based polymer dispersions due to fewer environmental concerns. Environmental regulations are becoming increasingly stringent in reducing the health risks of indoor exposure to air pollutants such as formaldehyde. Attempts have been made to reduce free formaldehyde released from indoor environments. For example, water-based acetyl groups in polymer binders have been developed as formaldehyde-eliminating materials for use in coating applications. However, the acetyl groups in the polymer tend to hydrolyze in water during storage, which can lead to pressure build-up in the container and create safety concerns. Furthermore, coating compositions containing these types of polymers tend to provide discolored (e.g., yellowing) films after storage, especially during heat aging.

[0003] The aim is to discover an aqueous polymer composition that can be used in coating applications without the aforementioned problems. Summary of the Invention

[0004] This invention addresses the problem of discovering waterborne compositions that can be used in coating applications without the aforementioned issues. The waterborne composition of this invention comprises a novel combination of an acetyl-functionalized acrylic copolymer and a specific amount of a polyhydroxy-functionalized amine. This waterborne composition provides films prepared therefrom that exhibit reduced yellowing without compromising other properties, including formaldehyde removal.

[0005] In a first aspect, the present invention is an aqueous composition comprising:

[0006] (a) An acrylic copolymer comprising, by weight, 1% to 10% of an olefinically unsaturated acetoacetyl functional monomer structural unit; and

[0007] (b) 0.11% to 0.9% by weight of a polyhydroxy functionalized amine having the structure of formula (I) based on the weight of the acrylic copolymer:

[0008]

[0009] Where R 1 It can be hydrogen, an alkyl group having 1 to 10 carbon atoms, or -(CH2). x -OH, where x is 1 to 5; m1 and m2 are each independently 1 to 10; and m3 is 0 to 10.

[0010] In a second aspect, the present invention provides a method for reducing yellowing of coatings made from aqueous compositions comprising acrylic copolymers. The method comprises incorporating a polyhydroxy functionalized amine into the aqueous composition at a weight percentage of 0.11% to 0.9% of the acrylic copolymer.

[0011] The acrylic copolymer comprises structural units of an olefinically unsaturated acetoacetyl functional monomer at a weight percentage of 1% to 10% based on the weight of the acrylic copolymer.

[0012] The polyhydroxy functional amine has the structure of formula (I):

[0013]

[0014] Where R 1 It can be hydrogen, an alkyl group having 1 to 10 carbon atoms, or -(CH2). x -OH, where x is 1 to 5; m1 and m2 are each independently 1 to 10; and m3 is 0 to 10. Detailed Implementation

[0015] As used herein, “aqueous” composition or dispersion means particles dispersed in an aqueous medium. “Aqueous medium” as used herein means water and 0% to 30% by weight of a water-miscible compound, such as alcohols, glycols, glycol ethers, glycol esters, or mixtures thereof.

[0016] As used herein, the “glass transition temperature” or “Tg” can be measured by various techniques, including, for example, differential scanning calorimetry (“DSC”) or calculations using the Fox formula. The Tg reported herein... g The specific value is the value calculated using the Fox formula (TGFox, Bulletin of the American Physical Society, Vol. 1, No. 3, p. 123 (1956)). For example, the T used to calculate the copolymer of monomers M1 and M2. g ,

[0017]

[0018] Where T g (Calculated) is the glass transition temperature calculated for the copolymer, w(M1) is the weight fraction of monomer M1 in the copolymer, w(M2) is the weight fraction of monomer M2 in the copolymer, T g (M1) is the glass transition temperature of the homopolymer of monomer M1, and T g(M2) is the glass transition temperature of the homopolymer of monomer M2; all temperatures are in K. The glass transition temperatures of the homopolymer can be found, for example, in "Polymer Handbook" edited by J. Brandrup and E. Himmergut, Interscience Publishers.

[0019] The "structural unit" (also called the "polymerization unit") of a named monomer refers to the residue of the monomer after polymerization; that is, the polymerized monomer or the monomer in polymerized form. For example, the structural unit of methyl methacrylate is shown below: The dashed lines represent the attachment points between the structural units and the polymer backbone.

[0020] The aqueous compositions of the present invention comprise (a) one or more acrylic copolymers and (b) one or more polyhydroxy functionalized amines. As used herein, “acrylic copolymer” refers to a copolymer of an acrylic monomer with different acrylic monomers or other monomers such as styrene. As used herein, “acrylic monomer” may include, for example, (meth)acrylic acid, (meth)alkyl acrylate, (meth)acrylamide, (meth)acrylonitrile, and modified forms thereof, such as (meth)hydroxyalkyl acrylate. Throughout this document, the word fragment “(meth)acryloyl” refers to both “methacryloyl” and “acryloyl”. For example, (meth)acrylic acid refers to both methacrylic acid and acrylic acid, and methyl methacrylate refers to both methyl methacrylate and methyl acrylate.

[0021] The acrylic copolymer (a) used in this invention is an acetoacetyl-functionalized acrylic copolymer. The acrylic copolymer comprises structural units of one or more olefinically unsaturated acetoacetyl-functionalized monomers (i.e., monomers having one or more acetoacetyl functional groups). The acetoacetyl functional group as used herein can be represented by the following formula:

[0022]

[0023] Where R is hydrogen, or an alkyl group having 1 to 10 carbon atoms, or a phenyl group.

[0024] Alkene-bonded unsaturated acetoacetyl functional monomers can be alkene-bonded unsaturated acetoacetoxy or acetoacetamide functional monomers. Examples of suitable acetoacetoxy or acetoacetamide functional groups include...

[0025]

[0026] Where X is O or N, R1 is a divalent free radical, and R2 is a trivalent free radical, which connects the acetylacetoxy or acetylacetamide functional group to the main chain of the acrylic copolymer.

[0027] Suitable olefinically unsaturated acetoacetyl functional monomers may include, for example, acetoacetoxyalkyl esters of (meth)acrylate, such as acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate, acetoacetoxypropyl methacrylate, acetoacetoxybutyl methacrylate, and 2,3-di(acetoacetoxy)propyl methacrylate; allyl acetoacetate; acetoacetaminoalkyl esters of (meth)acrylate, such as acetoacetaminoethyl methacrylate and acetoacetaminoethyl acrylate; or combinations thereof.

[0028] The acrylic copolymers used in this invention may contain 1% or more, 1.5% or more, 2% or more, 2.5% or more, 3% or more, 3.5% or more, or even 4% or more by weight of the acrylic copolymer, and simultaneously 10% or less, 9.5% or less, 9% or less, 8.5% or less, 8% or less, 7.5% or less, 7% or less, 6.5% or less, 6% or less, 5.5% or less, or even 5% or less of the structural units of the olefinically bonded unsaturated acetoacetyl functional monomer.

[0029] Acrylic copolymers used in this invention may also comprise structural units of one or more mono-olefinically unsaturated ionic monomers. The term "ionic monomer" as used herein refers to a monomer that does not carry an ionic charge between pH 1 and 14. Mono-olefinically unsaturated ionic monomers may include, for example, carboxylic acid monomers, phosphorus-containing acid monomers, sulfonic acid monomers, sulfate monomers; their salts; or mixtures thereof. Carboxylic acid monomers may be α,β-olefinically unsaturated carboxylic acids, monomers with acid-forming groups that generate or subsequently convert to such acid groups (e.g., acid anhydrides, (meth)acrylic anhydrides, or maleic anhydrides); or mixtures thereof. Specific examples of carboxylic acid monomers include acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, fumaric acid, or mixtures thereof. Sulfonic acid monomers and their salts may include sodium vinyl sulfonate (SVS), sodium styrene sulfonate (SSS), and sodium acrylamide-methyl-propane sulfonate (AMPS), or mixtures thereof. Suitable phosphorus-containing acid monomers and their salts may include, for example, alkyl phosphoacrylates of (meth)acrylate, such as ethyl phosphoacrylate, propyl phosphoacrylate, butyl phosphoacrylate, their salts, or mixtures thereof; CH2=C(R p )-C(O)-O-(R q O) n -P(O)(OH)2, where R p =H or CH3, R q= Alkylene groups, such as ethylene, propylene, butylene, or combinations thereof; and n = 1 to 20, such as SIPOMER PAM-100, SIPOMER PAM-200, SIPOMER PAM-300, SIPOMER PAM-600, and SIPOMER PAM-4000, all available from Solvay; (meth)acrylate phosphonoalkoxy esters, such as ethylene glycol phosphonoacrylate, diethylene glycol phosphonoacrylate, triethylene glycol phosphonoacrylate, propylene glycol phosphonoacrylate, dipropylene glycol phosphonoacrylate, tripropylene glycol phosphonoacrylate, their salts, or mixtures thereof. A preferred phosphorus-containing acid monomer is ethyl methacrylate (PEM). The acrylic copolymer may contain structural units of polyene-bonded unsaturated ionic monomers in amounts of 0.05% to 10% by weight, 0.3% to 8% by weight, 0.5% to 5% by weight, or 1% to 3% by weight, based on the weight of the acrylic copolymer.

[0030] The acrylic copolymers used in this invention may comprise one or more structural units of mono-olefinically unsaturated nonionic monomers, which are different from olefinically unsaturated acetoacetyl functional monomers. Hereinafter, the term "nonionic monomer" refers to a monomer that does not carry an ionic charge between pH 1 and 14. Mono-olefinically unsaturated nonionic monomers may include the C1-C6 groups of (meth)acrylic acid. 20 -alkyl esters, C1-C 10-Alkyl esters or C1-C8-alkyl esters. Examples of suitable mono-olefinic unsaturated nonionic monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, lauryl acrylate, butyl methacrylate, isodecyl methacrylate, lauryl methacrylate, hydroxy-functional (meth)acrylate alkyl esters such as hydroxyethyl methacrylate and hydroxypropyl methacrylate; (meth)acrylamide; (meth)acrylonitrile; urea-functional monomers such as hydroxyethyl ethylidene methacrylate; (meth)acrylate cycloalkyl esters such as (meth)acrylate cyclohexyl acrylate, methyl cyclohexyl acrylate, (meth)acrylate isobornyl ester and dihydrodicyclopentadienyl acrylate; monomers with carbonyl groups such as diacetone acrylamide (DAAM); vinyl aromatic monomers, including styrene and substituted styrene, such as α-methyl Styrene, p-methylstyrene, tert-butylstyrene, vinyltoluene, or mixtures thereof; vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(2-methoxyethoxy)silane, vinyldimethylethoxysilane, and vinylmethyldiethoxysilane; (meth)acryloylfunctional silanes, including, for example, (meth)acryloyloxyalkyltrialkoxysilanes such as γ-methacryloyloxypropyltrimethoxysilane and methacryloyloxypropyltriethoxysilane; 3-methacryloyloxypropylmethyldimethoxysilane; 3-methacryloyloxypropyltrimethoxysilane; and 3-methacryloyloxypropyltriethoxysilane; α-olefins such as ethylene, propylene, and 1-decene; vinyl acetate, vinyl butyrate, vinyl tert-carbonate, and other vinyl esters; glycidyl (meth)acrylate; or combinations thereof. Preferred olefinically unsaturated nonionic monomers are butyl acrylate, butyl methacrylate, methyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate, vinyltrimethoxysilane, styrene, or mixtures thereof. The acrylic copolymer may contain 80% to 98.9% by weight, 85% to 96% by weight, or 90% to 95% by weight of a monoolefinically unsaturated nonionic monomer structural unit based on the weight of the acrylic copolymer.

[0031] The acrylic copolymers used in this invention may optionally comprise structural units of one or more polyene-bonded unsaturated monomers, including difunctional, trifunctional, tetrafunctional, or higher polyfunctional polyene-bonded unsaturated monomers. Suitable polyene-bonded unsaturated monomers may include, for example, allyl (meth)acrylate, diallyl phthalate, divinylbenzene, ethylene glycol dimethacrylate, butylene dimethacrylate, or mixtures thereof. The acrylic copolymer may comprise structural units of polyene-bonded unsaturated monomers in amounts of zero or more, 0.05% or more, or even 0.1% or more, and simultaneously 5% or less, 3% or less, 1% or less, or even 0.5% or less, based on the weight of the acrylic copolymer.

[0032] The types and amounts of the monomers mentioned above can be selected to provide acrylic copolymers with Tg suitable for different applications. The Tg of the acrylic copolymer can be in the range of -20°C to 30°C, -15°C to 20°C, -10°C to 15°C, or -5°C to 10°C, as calculated by the Fox formula mentioned above.

[0033] The acrylic copolymers used in this invention can be prepared by free radical polymerization, preferably emulsion polymerization, of the monomers described above. The total weight concentration of the monomers used to prepare the acrylic copolymer is equal to 100%. The monomers can be added purely or in the form of an emulsion in water; or added in one or more forms or continuously, linearly or non-linearly during the reaction time for preparing the acrylic copolymer. The suitable temperature for the polymerization process can be below 100°C, in the range of 30°C to 95°C, or in the range of 50°C to 90°C. One or more surfactants can be used to prepare the acrylic copolymer. The surfactants can be added before, during or after the monomer polymerization, or in combination thereof. These surfactants can include anionic and / or nonionic emulsifiers, such as, for example, phosphate surfactants, sulfate surfactants, sulfonate surfactants and succinate surfactants; polymerizable surfactants; or mixtures thereof. The surfactants used are typically 0 to 5% by weight, 0.5% to 3% by weight or 0.8% to 2% by weight of the total weight of the monomers used to prepare the acrylic copolymer.

[0034] In the polymerization process, free radical initiators and / or chain transfer agents can be used. The polymerization process can be a thermally initiated or redox-initiated free radical polymerization. Examples of suitable free radical initiators include hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium and / or alkali metal persulfates, sodium perborate, superphosphate and their salts; ammonium or alkali metal salts of potassium permanganate and peroxydisulfuric acid. Free radical initiators can typically be used in amounts from 0.01% to 3.0% by weight of the total monomer weight. In the polymerization process, a redox system comprising the above-mentioned initiators and a suitable reducing agent can be used. Examples of suitable reducing agents include sodium formaldehyde sulfoxylate, ascorbic acid, isoascorbic acid, alkali metal salts and ammonium salts of sulfur-containing acids (such as sodium sulfite, bisulfite, thiosulfate, hyposulfite, sulfide, hydrosulfide, or dithionite), acetone bisulfite, glycolic acid, hydroxymethyl sulfonic acid, glyoxylate hydrate, lactic acid, glyceric acid, malic acid, tartaric acid, and salts of the aforementioned acids. Metal salts of iron, copper, manganese, silver, platinum, vanadium, nickel, chromium, palladium, or cobalt can be used to catalyze redox reactions. Metal chelating agents may be used optionally. Examples of suitable chain transfer agents include 3-mercaptopropionic acid, n-dodecyl mercaptan, methyl 3-mercaptopropionate, butyl 3-mercaptopropionate, benzenethiol, alkyl azelaic acid mercaptan, or mixtures thereof. Chain transfer agents can be used in an effective amount, based on the total weight of the monomers used to prepare the acrylic copolymer, to control the molecular weight of the acrylic copolymer, for example, 0 to 1 wt%, 0.1 wt% to 0.5 wt%, or 0.15 wt% to 0.4 wt%.

[0035] After polymerization, the resulting acrylic copolymer dispersion may be neutralized in significant amounts by one or more bases as neutralizing agents to adjust the pH to, for example, 6 to 10, 7 to 10, or 8 to 9.5. The base may result in partial or complete neutralization of the ionic or potential ionic groups of the acrylic copolymer. Bases suitable for use in this invention may be selected from the group consisting of: ammonia, primary amines having fewer than 2 (<2) hydroxyl groups, alkaline earth metal compounds, or mixtures thereof. “Primary amine” refers to an amine (-NH2) containing one or more primary amine groups. Examples of suitable primary amines include monoethanolamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, glycine, polyether amines such as JEFFAMINE D230 and D400 amines available from Huntsman Corporation, or mixtures thereof. Examples of suitable alkaline earth metal compounds include sodium hydroxide, potassium hydroxide, calcium hydroxide, zinc oxide, magnesium oxide, sodium carbonate, or mixtures thereof. Preferred bases are primary amines. The primary amine can be present in acrylic copolymers in molar ratios of primary amine groups (-NH2) to acetoacetyl functional groups in the range of 0.3 to 1.5, 0.4 to 1.4, 0.5 to 1.3, 0.6 to 1.2, 0.7 to 1.2, 0.8 to 1.1, or 0.9 to 1.0.

[0036] The acrylic copolymer particles in the aqueous compositions of the present invention may have a particle size of 50 nanometers (nm) to 500 nm, 80 nm to 200 nm, or 90 nm to 150 nm. Particle size as used herein refers to the Z-mean size and can be measured using a Brookhaven BI-90Plus particle size analyzer.

[0037] The aqueous composition of the present invention further comprises one or more polyhydroxy functionalized amines having the structure of formula (I):

[0038]

[0039] Where R 1 It can be hydrogen, an alkyl group having 1 to 10 carbon atoms, or -(CH2). x -OH, where x is 1 to 5; m1 and m2 are each independently 1 to 10; and m3 is 0 to 10.

[0040] R 1 It can be an alkyl group having 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 7 carbon atoms, or 1 to 4 carbon atoms. The value of x can be 1 to 5, 1 to 4, 1 to 3, or 1 to 2. m1 and m2 can each independently be 1 to 10, 1 to 8, 1 to 6, or 1 to 5. m3 can be 0 to 10, 0 to 8, 0 to 5, or 0 to 1. Preferably, R 1 -(CH2) x -OH, where x is 1 to 2.

[0041] Examples of suitable polyhydroxy functionalized amines include tris-(hydroxymethyl)aminomethane (Tris-A, ), tris(hydroxymethyl)aminoethane Tris(hydroxyethyl)aminomethane 2-Amino-1,3-propanediol (APL) ), 2-amino-2-ethyl-1,3-propanediol (AEPL, ) or mixtures thereof.

[0042] Preferably, the polyhydroxy functional amine is selected from the group consisting of: tris(hydroxymethyl)aminomethane, 2-amino-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, or mixtures thereof.

[0043] The polyhydroxy functionalized amines used in this invention can be included in the aqueous composition during and / or after the polymerization process for preparing the acrylic copolymer. Preferably, the functionalized amine is added after the polymerization process for preparing the acrylic copolymer is completed; more preferably, the functionalized amine is added after the addition of the neutralizing agent.

[0044] The aqueous composition of the present invention may contain, based on the weight of the acrylic copolymer, 0.11% or more, 0.12% or more, 0.13% or more, 0.14% or more, 0.15% or more, 0.16% or more, 0.17% or more, 0.18% or more, 0.19% or more, 0.2% or more, 0.22% or more, 0.25% or more, 0.28% or more, 0 ... 0.30% by weight or more, 0.32% by weight or more, 0.35% by weight or more, 0.38% by weight or more or even 0.4% by weight or more, and simultaneously 0.90% by weight or less, 0.85% by weight or less, 0.80% by weight or less, 0.75% by weight or less, 0.70% by weight or less, 0.65% by weight or less, 0.60% by weight or less, 0.55% by weight or less or even 0.5% by weight or less of polyhydroxy functional amines.

[0045] The aqueous compositions of the present invention are particularly suitable for coating applications. The aqueous compositions can be coating compositions and may also contain pigments, extenders, defoamers, thickeners, wetting agents, dispersants, agglomerates, biocides, or mixtures thereof.

[0046] The aqueous compositions of the present invention may comprise one or more pigments. As used herein, "pigment" refers to a particulate inorganic material that can substantially contribute to the opacity or hiding power of a coating. Such materials typically have a refractive index greater than 1.8. Inorganic pigments may include, for example, titanium dioxide (TiO2), zinc oxide, iron oxide, zinc sulfide, barium sulfate, barium carbonate, or mixtures thereof. In a preferred embodiment, the pigment used in the present invention is TiO2. TiO2 typically exists in two crystalline forms, namely anatase and rutile. TiO2 can also be obtained in concentrated dispersion form.

[0047] The aqueous compositions of the present invention may contain one or more extenders. The term "extensioner" as used herein refers to a particulate inorganic material having a refractive index less than or equal to 1.8 and greater than 1.3. Examples of suitable extenders include calcium carbonate, clay, calcium sulfate, aluminum silicate, silicates, zeolite, mica, diatomaceous earth, solid or hollow glass, ceramic beads, nepheline syenite, feldspar, diatomaceous earth, calcined diatomaceous earth, talc (hydrated magnesium silicate), silica, alumina, kaolin, pyrophyllite, perlite, barite, wollastonite, and opaque polymers (such as ROPAQUE, available from The Dow Chemical Company). TM Ultra E (ROPAQUE is a trademark of Dow Chemical Company) or mixtures thereof.

[0048] The aqueous compositions of the present invention may have a pigment volume concentration (PVC) of 8% or more, 10% or more, 20% or more, 30% or more, and simultaneously 80% or less, 65% or less, or even 5% or less. The PVC can be determined by the following formula: PVC = (Volume of pigment and extender / Dry volume of aqueous composition) * 100%

[0049] The aqueous compositions of the present invention may contain one or more defoamers. The term "defoamer" as used herein refers to a chemical additive that reduces and inhibits foam formation. Defoamers may be silicone-based defoamers, mineral oil-based defoamers, ethylene oxide / propylene oxide defoamers, alkyl polyacrylates, or mixtures thereof. Suitable commercially available defoamers include, for example, TEGO Airex 902W and TEGO Foamex 1488 polyether silicone copolymer emulsions, both available from TEGO, and BYK-024 silicone defoamer, or mixtures thereof, available from BYK. The defoamer may be present in amounts of 0 to 2% by weight, 0.1% to 1.5% by weight, or 0.2% to 1% by weight of the total weight of the coating composition.

[0050] The aqueous compositions of the present invention may contain one or more thickeners. Thickeners may include polyvinyl alcohol (PVA), clay materials, acid derivatives, acid copolymers, urethane associative thickeners (UAT), polyether urea polyurethane (PEUPU), polyether polyurethane (PEPU), or mixtures thereof. Examples of suitable thickeners include alkali-swellable emulsions (ASE), such as sodium or ammonium-neutralized acrylic polymers; hydrophobically modified alkali-swellable emulsions (HASE), such as hydrophobically modified acrylic copolymers; associative thickeners, such as hydrophobically modified ethoxylated urethane (HEUR); and cellulose thickeners, such as methyl cellulose ether, hydroxymethyl cellulose (HMC), hydroxyethyl cellulose (HEC), hydrophobically modified hydroxyethyl cellulose (HMHEC), sodium carboxymethyl cellulose (SCMC), sodium carboxymethyl 2-hydroxyethyl cellulose, 2-hydroxypropyl methylcellulose, 2-hydroxyethyl methylcellulose, 2-hydroxybutyl methylcellulose, 2-hydroxyethyl ethyl cellulose, and 2-hydroxypropyl cellulose. Preferably, the thickener is hydrophobically modified hydroxyethyl cellulose (HMHEC). The thickener may be present in an amount of 0 to 4 dry weight%, 0.2 to 3 dry weight%, or 0.4 to 2 dry weight% based on the total weight of the aqueous composition.

[0051] The aqueous compositions of the present invention may contain one or more wetting agents. The term "wetting agent" as used herein refers to a chemical additive that reduces the surface tension of the coating composition, thereby facilitating diffusion or penetration across or into the substrate surface. The wetting agent may be anionic, amphoteric, or nonionic polycarboxylate. The wetting agent may be present in amounts of 0 to 3 wt%, 0.1 wt% to 2.5 wt%, or 0.2 wt% to 2 wt% based on the total weight of the aqueous composition.

[0052] The aqueous compositions of the present invention may contain one or more dispersants. Dispersants may include nonionic, anionic, or cationic dispersants, such as polybasic acids having suitable molecular weights, 2-amino-2-methyl-1-propanol (AMP), dimethylaminoethanol (DMAE), potassium tripolyphosphate (KTPP), trisodium polyphosphate (TSPP), citric acid, and other carboxylic acids. The polybasic acids used may include homopolymers and copolymers based on polycarboxylic acids (e.g., with a weight-average molecular weight in the range of 1,000 g / mol to less than 50,000 g / mol, as measured by gel permeation chromatography (GPC)), including those that have been hydrophobically or hydrophilically modified, such as polyacrylic acid or polymethacrylic acid or maleic anhydride, and various monomers (such as styrene, acrylates or methacrylates, diisobutylene, and other hydrophilic or hydrophobic comonomers); their salts; or mixtures thereof. The dispersant may be present in amounts of 0 to 3 dry weight%, 0.1 to 2 dry weight%, 0.2 to 1.5 dry weight%, or 0.3 to 1.2 dry weight% based on the total weight of the aqueous composition.

[0053] The aqueous compositions of the present invention may comprise one or more coalescing agents. The term "coalescing agent" as used herein refers to a slowly volatile solvent that fuses polymer particles into a continuous film under ambient conditions. Examples of suitable coalescing agents include 2-n-butoxyethanol, dipropylene glycol n-butyl ether, propylene glycol n-butyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol n-propyl ether, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, triethylene glycol monobutyl ether, dipropylene glycol n-propyl ether, n-butyl ether, or mixtures thereof. Preferably, the coalescing agent comprises dipropylene glycol n-butyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, n-butyl ether, or mixtures thereof. The coalescing agent may be present in an amount of 0 to 30% by weight, 0.1% to 20% by weight, or 0.5% to 15% by weight based on the total weight of the aqueous composition.

[0054] In addition to the components described above, the aqueous compositions of the present invention may also contain any one or a combination of the following additives: buffers, neutralizers, photocrosslinkers, antifreeze agents, humectants, fungicides, biocides, anti-skinning agents, colorants, flow agents, antioxidants, plasticizers, leveling agents, thixotropic agents, tackifiers, and abrasives. These additives may be present in combinations of 0 to 5% by weight, 0.1% to 4% by weight, or 0.5% to 3% by weight of the total weight of the aqueous composition.

[0055] The solid content of the aqueous composition of the present invention can be 30% to 80% by weight, 40% to 70% by weight, or 50% to 60% by weight, based on the total weight of the aqueous composition.

[0056] The waterborne coating compositions of the present invention can be prepared by adding a polyhydroxy functionalized amine during and / or after the polymerization process for preparing the acrylic copolymer and optionally mixing it with the other optional components described above. Preferably, the waterborne coating compositions are prepared by mixing the polyhydroxy functionalized amine with the acrylic copolymer. The components in the waterborne composition can be mixed in any order to provide the waterborne compositions of the present invention. Any of the optional components described above can also be added to the waterborne composition during or before mixing to form the waterborne composition.

[0057] The aqueous compositions of this invention can be applied to and adhere to a variety of substrates. Examples of suitable substrates include wood, metal, plastic, foam, stone, elastic substrates, glass, textiles, concrete, or cement substrates. Waterborne compositions preferably containing pigments are suitable for a wide range of applications, such as marine and protective coatings, automotive coatings, road marking paints, external insulation and finishing systems (EIFS), roofing adhesives, wood coatings, coil coatings, plastic coatings, powder coatings, can coatings, architectural coatings, and civil engineering coatings, particularly architectural coatings. The aqueous compositions can be applied to substrates by existing methods, including brushing, dipping, rolling, and spraying (preferably by spraying). Standard spraying techniques and equipment, such as air atomization spraying, air spraying, airless spraying, high-volume low-pressure spraying, and electrostatic spraying (e.g., electrostatic bell application), as well as manual or automated methods, can be used. After the aqueous composition is applied to a substrate, it can be dried or allowed to dry at room temperature (20°C to 25°C) or at a high temperature (e.g., 35°C to 80°C) to form a film (i.e., a coating).

[0058] Compared to similar aqueous compositions lacking only polyhydroxy functional amines after heat aging at 65°C for one month (hereinafter referred to as "existing aqueous compositions"), the aqueous compositions of the present invention, after heat aging at 65°C for one month, provide films prepared therefrom with less yellowing. The aqueous compositions of the present invention provide films prepared therefrom, as well as resulting coated substrates with reduced or low yellowing. "Reduced or low yellowing" or "reduced or low yellowing" means that the difference in b-values ​​(i.e., Δb) between the aqueous composition before and after heat aging at 65°C for one month is not greater than 0.6, preferably not greater than 0.5. Yellowing performance can be determined according to the test methods described in the Examples section below.

[0059] The present invention also provides a method for reducing yellowing of coatings made from aqueous compositions comprising acrylic copolymers (i.e., "existing aqueous compositions"), comprising: incorporating a polyhydroxy functionalized amine into the aqueous composition, for example, mixing the polyhydroxy functionalized amine with the acrylic copolymer. A film can be prepared by drying the aqueous composition as described above. "Reduces yellowing" as used herein refers to the aforementioned reduced yellowing in coatings made therefrom, compared to existing aqueous compositions lacking only the polyhydroxy functionalized amine after heat aging at 65°C for one month.

[0060] The present invention also includes a method for removing aldehydes from aldehyde-containing air using the aqueous composition of the present invention, comprising: applying the aqueous composition to a substrate; and drying or allowing the applied aqueous composition to dry to form a film. The substrate and drying conditions are as described above. The aqueous composition of the present invention also provides good formaldehyde removal properties to meet the requirements of JC / T 1074-2008 (China Building Materials Industry Standard on the Purification Performance of Air Purification Functional Coating Materials), for example, showing a formaldehyde removal efficiency of ≥75%, preferably 80% or higher, or even 84% or higher.

[0061] Example

[0062] Some embodiments of the invention will now be described in the following examples, wherein all parts and percentages are by weight unless otherwise stated.

[0063] Styrene (ST), butyl acrylate (BA), and methacrylic acid (MAA) are available from Dow Chemical Company.

[0064] Acetylacetyloxyethyl methacrylate (AAEM) is available from Eastman.

[0065] Sodium styrene sulfonate (SSS), tetrasodium ethylenediaminetetraacetic acid (EDTA), tert-butyl hydroperoxide (t-BHP), monoethanolamine (MEA), tris(hydroxymethyl)aminomethane (Tris-A), 2-amino-1,3-propanediol (APL), and 2-amino-2-ethyl-1,3-propanediol (AEPL) are available from Sinopharm Chemical Reagent Co., Ltd.

[0066] POLYSTEP P-12A alkylethoxylated ammonium phosphate salt is available from Stepan.

[0067] DISPONIL Fes-32 alkylethoxylated sodium sulfate is available from BASF.

[0068] Bruggolite FF6M (FF-6) is available from Brueggemann Chemical.

[0069] The following standard analytical equipment and methods were used in the embodiments to determine the properties and characteristics described herein:

[0070] Formaldehyde removal efficiency

[0071] The formaldehyde (FA) elimination efficiency of paint formulations is evaluated according to the JC / T1074-2008 standard. After 24 hours, the FA efficiency needs to be ≥75% to meet the requirements of JC / T 1074-2008. Higher FA efficiency indicates better FA elimination.

[0072] Yellowing resistance test

[0073] A portion of the paint formulation sample was applied to a LENETA Form 2A opaque card using a 100-micron (μm) doctor blade and allowed to dry overnight at room temperature. The b-value of the resulting coating was then measured using a colorimeter (a spectral guide sphere model from BYK), denoted as "b". 初始 ".

[0074] Another portion of the paint formulation sample was then placed in an oven at 65°C. After heat aging at 65°C for one month, the samples were removed and allowed to cool to room temperature. The resulting paint formulation was further applied onto a LENETA Form 2A opaque card using a 100μm doctor blade and dried overnight at room temperature. The b-value of the resulting coating was then measured using a colorimeter and is denoted as "b". 最终 The Delta b value (Δb) is determined by the following formula: Δb = b 最终 -b 初始The lower the Δb value, the less yellowing the coating film will exhibit. Acceptable yellowing performance is defined as a Δb value of no more than 0.6 (≤0.6) after one month of heat aging of the paint formulation at 65°C.

[0075] Solid content

[0076] The solids content of the aqueous composition sample is measured as follows: Weigh 0.7g ± 0.1g of sample (the wet weight of the sample is recorded as "W1"), place the sample in an aluminum pan in an oven at 150°C (the weight of the aluminum pan is recorded as "W2") for 25 minutes, and then cool to room temperature and weigh the aluminum pan containing the dried sample. The total weight is recorded as "W3". "W3-W2" refers to the dry or solid weight of the sample. The solids content is calculated by (W3-W2) / W1*100%.

[0077] Comparative Example (Comp Ex) A: Preparation of acetoacetyl functionalized acrylic copolymer A

[0078] Monomer emulsions were prepared by mixing deionized (DI) water (308.3 g), P-12A (25% active ingredient, 97.19 g), SSS (8.59 g), MAA (31.76 g), BA (927.44 g), ST (552.77 g), and AAEM (31.6 g). DI water (837 g) and Fes-32 (32% active ingredient, 5.5 g) were charged into a 1-gallon stirred reactor. After heating the reactor contents to 91°C, a sodium carbonate solution (1.56 g sodium carbonate dissolved in 18 g DI water), a monomer emulsion (48.6 g), and an ammonium persulfate (APS) solution (4.7 g APS dissolved in 16 g DI water) were added to the reactor. When the temperature reached 88°C, the remaining monomer emulsion and another APS solution (1.6 g APS dissolved in 54 g DI water) were gradually added over 90 minutes. The reactor temperature was maintained at 88°C. The monomer emulsion feed line leading to the reactor was flushed with DI water (38g). The reactor was cooled to 70°C, and then FeSO4·7H2O (0.013g) and EDTA tetrasodium salt solution (0.02g EDTA tetrasodium salt dissolved in 6g DI water) were added to the reactor. t-BHP solution (3.81g t-BHP (70% active ingredient) dissolved in 66g DI water) and FF-6 solution (1.9g FF-6 dissolved in 69g water) were fed into the reactor with stirring over 30 minutes. When the reactor temperature reached 50°C, a neutralizing agent solution (1.05g NaOH dissolved in 28g water and 8.92g MEA dissolved in 17g water) was fed into the reactor over 30 minutes to adjust the pH of the reactor contents (i.e., the neutralization step). The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition with a solids content of 47.1% and a pH of 9.0.

[0079] Comparative Example B

[0080] The procedure for preparing the acrylic copolymer in Comparative Example A was followed as described in Comparative Example B, except that (i) the monomer emulsion used in Comparative Example B was prepared by mixing DI water (308.3 g), P-12A (25% active ingredient, 97.19 g), SSS (8.59 g), MAA (31.76 g), BA (896.01 g), and ST (615.58 g); and (ii) after the neutralization step, a Tris-A solution (9.3 g Tris-A dissolved in 11 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Comparative Example B, which had a solids content of 46.5% and a pH of 9.4.

[0081] Comparative Example C

[0082] The procedure for preparing the acrylic copolymer in Comparative Example A was followed as described in Comparative Example C, except that after the neutralization step, an APL solution (1.55 g APL dissolved in 2 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Comparative Example C, which had a solids content of 46.8% and a pH of 9.1.

[0083] Comparative Example D

[0084] The procedure for preparing the acrylic copolymer in Comparative Example A was followed as described in Comparative Example D, except that after the neutralization step, an APL solution (15.5 g of APL dissolved in 18 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Comparative Example D, which had a solids content of 47.0% and a pH of 9.7.

[0085] Comparative Example E

[0086] The procedure for preparing the acrylic copolymer in Comparative Example A was followed as described in Comparative Example E, except that after the neutralization step, a MEA solution (4.65 g MEA dissolved in 5.4 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Comparative Example E, which had a solids content of 47.1% and a pH of 9.4.

[0087] Example 1

[0088] Example 1 was performed according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, a Tris-A solution (8.53 g Tris-A dissolved in 10 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 1, with a solids content of 47.2% and a pH of 9.5.

[0089] Example 2

[0090] Example 2 was performed according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an APL solution (2.32 g APL dissolved in 3 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 2, with a solids content of 47.1% and a pH of 9.1.

[0091] Example 3

[0092] Example 3 was performed according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an APL solution (3.10 g APL dissolved in 4 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 3, with a solids content of 47.0% and a pH of 9.3.

[0093] Example 4

[0094] Example 4 was performed according to the procedure for preparing the acrylic copolymer described in Comparative Example A, except that after the neutralization step, an APL solution (4.65 g of APL dissolved in 5 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 4, with a solids content of 47.1% and a pH of 9.4.

[0095] Example 5

[0096] Example 5 was performed according to the procedure for preparing the acrylic copolymer described in Comparative Example A, except that after the neutralization step, an APL solution (8.53 g of APL dissolved in 10 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 5, with a solids content of 47.3% and a pH of 9.5.

[0097] Example 6

[0098] Example 6 was carried out according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an APL solution (10.86 g of APL dissolved in 14 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 6, with a solids content of 47.3% and a pH of 9.6.

[0099] Example 7

[0100] Example 7 was carried out according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an APL solution (12.41 g of APL dissolved in 16 g of water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 7, with a solids content of 47.2% and a pH of 9.6.

[0101] Example 8

[0102] Example 8 was carried out according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an APL solution (13.97 g APL dissolved in 18 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 8, with a solids content of 47.2% and a pH of 9.7.

[0103] Example 9

[0104] Example 9 was carried out according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that after the neutralization step, an AEPL solution (4.65 g AEPL dissolved in 6.04 g water) was further added to the reactor under stirring. The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 9, which had a solids content of 47.2% and a pH of 9.3.

[0105] Example 10

[0106] Example 10 was conducted according to the procedure for preparing the acrylic copolymer in Comparative Example A above, except that the monomer emulsion and neutralizing agent solution used in Example 10 were different, and a certain amount of polyhydroxy functionalized amine was further added in Example 10, as detailed below:

[0107] Monomer emulsions were prepared by mixing DI water (308.3 g), P-12A (25% active ingredient, 97.19 g), SSS (8.59 g), MAA (31.76 g), BA (911.64 g), ST (536.97 g), and AAEM (63.2 g).

[0108] The neutralizing agent solution used in the neutralization step was a solution of 1.05 g NaOH dissolved in 28 g water and a solution of 17.84 g MEA dissolved in 17 g water. After the neutralization step, a Tris-A solution (8.53 g Tris-A dissolved in 16 g water) was further added to the reactor under stirring.

[0109] The contents were filtered through a 100-mesh (45 μm) filter to obtain the final aqueous composition of Example 10, which had a solids content of 47.3% and a pH of 9.3.

[0110] Paint formulation

[0111] Based on the formulations given in Table 1, the aqueous compositions obtained above were used as binders for preparing paint formulations. In the grinding stage, the components were mixed using a high-speed Cowles disperser at 1,000 to 1,300 rpm. Then, in the thinning stage, the components were added and mixed using a conventional mixer at 500 rpm. Binder was added in an amount that maintained the same solid weight in each paint formulation (the solid weight of the binder can be calculated as: (wet weight of binder * solid content of binder)). The amount of water added to each paint composition was adjusted so that the total amount of the paint formulation was equal to 1,000 g. The type of binder in each paint formulation is given in Table 1. The properties of the obtained paint formulations were evaluated according to the test methods described above, and the results are given in Table 2.

[0112] Table 1. Comparison of paint formulations for paint A

[0113]

[0114]

[0115] *OROTAN, ACRYSOL, and TERGITOL are trademarks of Dow Chemical Company.

[0116] As shown in Table 2, the binder of Comparative Example A, which contains only acetoacetyl functional copolymer (2% AAEM) and no polyhydroxy functional amine, provides unacceptable yellowing to coating A. Coating B, made from the binder of Comparative Example B, which contains Tris-A but no acetoacetyl functional polymer, fails to meet FA efficiency requirements. The binder of Comparative Example D, which contains a combination of 1% APL and acetoacetyl functional copolymer (2% AAEM), provides unacceptable yellowing to coating D, as indicated by a high Δb value (>0.6). Combining 0.1% APL or MEA with acetoacetyl functional copolymers (Comparative Examples C and E) results in coatings C or E exhibiting more severe yellowing than coating A.

[0117] Compared to the binder of Comparative Example A, the binder of Example 1, which included a combination of Tris-A and an acetoacetyl functional copolymer (2% AAEM), provided a significantly reduced yellowing for coating 1. Furthermore, binders combining this acetoacetyl functional copolymer with specific amounts of APL (Examples 2 to 8) or AEPL (Example 9) also provided no significant yellowing for coatings 2 to 9. The binder of Example 10, which combined Tris-A with an acetoacetyl functional copolymer (4% AAEM), also provided an acceptable level of yellowing for coating 10. Moreover, coatings 1 to 6 and 9 to 10 showed even less yellowing than coatings 7 to 8. All paint formulations of the present invention (paints 1 to 10) also meet the FA efficiency requirements of JC / T1074-2008.

[0118] Table 2. Coating Formulations and Properties

[0119]

[0120] 1 AAEM percentage refers to the weight percentage of AAEM structural units relative to the weight of the acrylic copolymer; polyhydroxy functionalized amine percentage refers to the weight percentage of polyhydroxy functionalized amines relative to the weight of the acrylic copolymer; MEA percentage refers to the weight percentage of MEA (excluding MEA in the neutralizing agent solution used in the neutralization step).

[0121] 2 The efficiency of FA was determined according to JC / T1074-2008.

[0122] 3 Δb refers to the Δb before and after heat aging at 65℃ for 1 month.

Claims

1. An aqueous composition comprising: (a) An acrylic copolymer comprising structural units of an olefinically unsaturated acetylacetyl functional monomer at a weight percentage of 1% to 10% by weight of the acrylic copolymer; and (b) 0.11% to 0.9% by weight of a polyhydroxy functionalized amine having the structure of formula (I) based on the weight of the acrylic copolymer: I) Where R 1 It can be hydrogen, an alkyl group having 1 to 10 carbon atoms, or –(CH2). x -OH, where x is 1 to 5; m1 and m2 are each independently 1 to 10; and m3 is 0 to 10; The olefinically unsaturated acetoacetyl functional monomer is selected from (meth)acrylate acetoacetoxyalkyl ester; allyl acetoacetate; (meth)acrylate acetoacetaminoalkyl ester; or combinations thereof.

2. The aqueous composition according to claim 1, wherein, In equation (I), m1 and m2 are each independently 1 to 5, and m3 is 0 to 1.

3. The aqueous composition according to claim 1 or 2, wherein, In equation (I), R 1 For –(CH2) x -OH, where x is 1 to 2.

4. The aqueous composition according to claim 1 or 2, wherein the polyhydroxy functional amine is selected from the group consisting of: tris(hydroxymethyl)aminomethane, tris(hydroxymethyl)aminoethane, tris(hydroxyethyl)aminomethane, 2-amino-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol or mixtures thereof.

5. The aqueous composition according to claim 1 or 2, wherein the aqueous composition comprises 0.15% to 0.7% by weight of the polyhydroxy functional amine based on the weight of the acrylic copolymer.

6. The aqueous composition according to claim 1 or 2, wherein the aqueous composition further comprises a primary amine having fewer than two hydroxyl groups.

7. The aqueous composition of claim 6, wherein the primary amine is present in an amount providing a molar ratio of 0.3 to 1.5 of the primary amine group to the acetoacetyl functional group in the acrylic copolymer.

8. The aqueous composition according to claim 1 or 2, wherein the olefinically unsaturated acetoacetyl functional monomer is selected from the group consisting of: acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate, acetoacetoxypropyl methacrylate, acetoacetoxybutyl methacrylate, 2,3-di(acetoacetoxy)propyl methacrylate, allyl acetoacetate, or mixtures thereof.

9. The aqueous composition according to claim 1 or 2, wherein the polyhydroxy functional amine is selected from the group consisting of: tris(hydroxymethyl)aminomethane, and the olefinic unsaturated acetoacetyl functional monomer is selected from acetoacetoxyethyl methacrylate.

10. The aqueous composition according to claim 1 or 2, wherein the aqueous composition further comprises pigments, extenders, defoamers, thickeners, wetting agents, dispersants, agglomerants, biocides, or mixtures thereof.

11. A membrane made of the aqueous composition according to any one of claims 1-10.

12. A method for reducing yellowing of a coating made from an aqueous composition comprising an acrylic copolymer, the method comprising: The aqueous composition is incorporating 0.11% to 0.9% by weight of a polyhydroxy functional amine based on the weight of the acrylic copolymer; The acrylic copolymer comprises 1% to 10% by weight of an olefinically unsaturated acetoacetyl functional monomer structural unit based on the weight of the acrylic copolymer; and The polyhydroxy functional amine described therein has the structure of formula (I): (I) Where R 1 It can be hydrogen, an alkyl group having 1 to 10 carbon atoms, or –(CH2). x -OH, where x is 1 to 5; m1 and m2 are each independently 1 to 10; and m3 is 0 to 10; The olefinically unsaturated acetoacetyl functional monomer is selected from (meth)acrylate acetoacetoxyalkyl ester; allyl acetoacetate; (meth)acrylate acetoacetaminoalkyl ester; or combinations thereof.

13. The method according to claim 12, wherein the polyhydroxy functional amine is selected from the group consisting of: tris(hydroxymethyl)aminomethane, tris(hydroxymethyl)aminoethane, tris(hydroxyethyl)aminomethane, 2-amino-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, or mixtures thereof.

14. The method according to claim 12 or 13, wherein the olefinic unsaturated acetoacetyl functional monomer is selected from acetoacetoxyethyl methacrylate.

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