Viscosity stabilizing additive for universal colorants

Abstract

A universal colorant composition is described for use with both a water-based and a solventbased paint or coating. The universal colorant composition comprises a colorant and a viscosity stabilizing compound. Also described is a paint or coating system comprising a base paint or base coating, and the universal colorant composition.

Description

VISCOSITY STABILIZING ADDITIVE FOR UNIVERSAL COLORANTSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 556,603, filed on February 22, 2024, the disclosure of which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION

[0002] The invention relates to a universal colorant composition for use with both a waterbased and a solvent-based paint or coating. The invention further relates to a paint or a coating system and to a method of manufacturing a finished paint or coating. The invention also relates to the use of a viscosity stabilizing compound and to the use of the universal colorant composition.BACKGROUND

[0003] There are several varieties of paints or coatings, which differ significantly by their chemical compositions. For example, in the case of a paint, the paint may be a latex paint, an alkyd paint (also known as an enamel paint), an epoxy paint (also known as a plastic paint or a two-part paint) or a urethane paint. The underlying chemistries for each of these types of paint are very different.

[0004] Universal colorants are used in the painting and coating industry to provide a single pigment dispersion that is compatible with several types of paints and coatings. In general, the universal colorant is used to tint or adjust the color of a base paint either in the plant for the product or in shops where the end users buy the paint or coating. This avoids the need to formulate a specific pigment dispersion for each type of chemistry upon which the paint or coating is based.

[0005] Formulating a universal colorant is challenging. A wide range of different color pigments must be stabilized, ideally using as few additives as possible. It can be difficult to prepare a colorant for a paint or coating based on a single type of chemistry (e.g. water-based paints or coatings) because, even within a single type of paint or coating, there may be a wide variety of formulations. The development of a universal colorant for paints or coatings employing several different types of chemistry presents further difficulties.

[0006] Associative thickeners are used to impart improved flow and levelling to latex coatings, also known as emulsion paints and coatings. It is believed that the associative thickeners function by forming reversible networks throughout a coating formulation via hydrophobic interactions with pigment, filler, latex resin, and other particles and via micellar interactions. This thickening mechanism, and therefore paints or coatings formulated with these thickeners, often react poorly to addition of surfactants as may be encountered by addition of a universal colorant. The addition of the universal colorant often results in a large decrease in viscosity.

[0007] Similar viscosity losses also occur in associatively thickened paints or coatings formulated with water reducible, water dispersible and water-soluble resins. The surfactants that are generally included in universal colorants may disrupt the reversible network formed by the hydrophobically modified rheological additives. This network is responsible for the thickening and its disruption results in large decreases in viscosity.

[0008] Maintaining the viscosity is an important condition for a satisfactory paint or coating. Recently, several color viscosity stabilizing (CVS) paint or coating additives and associative thickeners have been introduced which are intended to counter this viscosity loss effect. While these CVS materials are effective in reducing the viscosity losses upon colorant addition in comparison to additives that are not designed for such application, the new CVS additives still show a significant drop in viscosity upon tinting, with some colorants being worse than others.SUMMARY OF THE INVENTION

[0009] The present invention provides a universal colorant composition for use with both a water-based paint and a solvent-based paint or both a water-based and a solvent-based coating. The universal colorant composition comprises: a colorant and a viscosity stabilizing compound.

[0010] As may be evident from their name color viscosity stabilizing (CVS) additives for paints or coatings are added to the base paint or the base coating before the addition of the universal colorant. The addition of the CVS additives in this way is intended to reduce or prevent a change in viscosity, particularly a reduction in or loss of viscosity, upon addition of the universal colorant to the base paint or base coating.

[0011] The loss of viscosity in a paint or coating upon tinting (e.g. addition of a prior art universal colorant) can be reduced or prevented by adding a viscosity stabilizing (VS) additive to the universal colorant instead of the base paint or base coating.

[0012] It has surprisingly been found that addition of the viscosity stabilizing (VS) additive to the universal colorant effectively mitigates the drop in viscosity upon tinting much better than when a universal colorant is added to a base paint or coating that already contains the CVS additive. In other words, the inclusion of the viscosity stabilizing (VS) additive as part of a universal colorant composition was unexpectedly found to be more effective than when the additive is added directly to a base paint or coating followed by addition of the colorant for tinting.

[0013] The improvement in the effectiveness of the VS additive when used in this way provides several advantages. A lower amount of the VS additive can be used to achieve the same mitigation in the loss of viscosity than the amount of CVS additive that needs to be added directly to the base paint or coating followed by the addition of the universal colorant. Consequently, the finished colored paint or coating will have comparable viscosity to a finished colored paint or coating produced using a CVS additive, except that the amount of VS additive in the paint or coating will be lower than the amount of CVS additive.

[0014] The enhanced effectiveness of the VS additive means that superior mitigation in the loss of viscosity can be obtained when the amount of VS additive that is used is the same as the amount of CVS additive.

[0015] A further advantage is that the finished colored paint or coating can be produced by mixing a base paint or base coating with a single product, which contains both a universal colorant and a viscosity stabilizing additive. This reduces the number of manufacturing steps that are to be performed on the base paint or base coating.

[0016] The invention further provides a paint system or a coating system. The paint system or the coating system comprises: (i) a base paint or base coating; and (ii) a universal colorant composition in accordance with the invention for addition to the base paint or the base coating. The paint or coating system is for the manufacture of a finished (e.g. colored) paint or coating.

[0017] The invention also provides a method of manufacturing a finished (e.g. colored) paint or coating. The method comprises: mixing a universal colorant composition in accordance with the invention with a base paint or a base coating.

[0018] The invention further relates to uses of the universal colorant composition.

[0019] The universal colorant composition may be used to reduce or prevent a change in the viscosity of a base paint or base coating upon addition of the universal colorant composition to the base paint or the base coating.

[0020] Additionally, or alternatively, the universal colorant composition may be used in the manufacture of a finished (e.g. colored) paint or coating.

[0021] The invention also provides a method of reducing or preventing a change in viscosity of a base paint or a base coating upon addition of a colorant. The method comprises: mixing a universal colorant composition in accordance with the invention with a base paint or a base coating.

[0022] The invention also relates to the use of a viscosity stabilizing compound in a universal colorant composition to reduce or prevent a change in the viscosity of a base paint or base coating upon addition of the universal colorant composition to the base paint or the base coating.

[0023] In general, the “change in viscosity” mentioned herein is a loss in viscosity.DETAILED DESCRIPTION

[0024] The following definitions apply to the disclosure herein, including all aspects of the invention and their embodiments.

[0025] The compounds and intermediates described herein may be named according to the IUPAC (International Union for Pure and Applied Chemistry) or the CAS (Chemical Abstracts Service) nomenclature systems or by their commercial trade names.

[0026] The expression “substantially free of VOCs” or “substantially free of VOC” as used herein refers to a total amount of volatile organic compound that provides a paint or a coating (e.g. the finished paint or coating for use) having less than 50.0 g per L of volatile organic compound (VOC), preferably from 5.0 to 30.0 g per L of VOC.

[0027] The term “colorant” as used herein refers to a compound or substance that is added to change the color of a material, in this case a base paint or base coating.

[0028] The number- average molecular weight (Mn) of various material, components or ingredients as described herein can be determined by conventional methods, such as gel permeation chromatography (GPC) using, for example, polystyrene as a standard.

[0029] The various hydrocarbon-containing moieties provided herein may be described using a prefix designating the minimum and maximum number of carbon atoms in the moiety, namely “Ca-Ct>”. For example, Ca-Cb alkyl indicates an alkyl moiety having the integer “a” to the integer “b” number of carbon atoms, inclusive.

[0030] As used herein, the term “alkyl”, whether used alone or in conjunction with another term, refers to a branched or unbranched saturated hydrocarbon chain, unless specified otherwise. An alkyl group is typically unsubstituted, unless indicated otherwise. An alkyl group may have 1 to 20 carbon atoms, such as 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms. Representative examples include, but are not limited to, methyl, ethyl, n- propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n- nonyl, n-decyl, isopropyl, tert-butyl, isobutyl, etc.

[0031] As used herein, the term “aryl”, whether used alone or in conjunction with another term, refers to phenyl and 7 to 10 membered ring systems in which at least one of the rings is aromatic. Ring systems may include bicyclic or tricyclic hydrocarbon ring systems, or bridged, spiro, and / or fused ring systems. An aryl group is unsubstituted unless specified otherwise. An aryl group may have 6 ring atoms (i.e. phenyl) or a ring system containing 7 to 10 atoms. Representative examples include, but are not limited to, naphthyl, indanyl and 1,2,3,4-tetrahydronaphthalenyl. In general, it is preferred that an aryl group is either phenyl or naphthyl, more preferably phenyl.

[0032] As used herein, the terms “aryl-alkyl”, “arylalkyl” or “arylalkyl group” refer to an alkyl group in which a hydrogen atom is replaced by an aryl group, wherein the alkyl group and the aryl group are as previously defined. An example is GrCw aryl-Ci-C4 alkyl, which includes benzyl (C6H5CH2-). Aryl-alkyl groups are typically unsubstituted.

[0033] As used herein, the terms “cycloalkyl” and “cycloalkyl group” refer to a non-aromatic carbocyclic ring system, that may be monocyclic, bicyclic, or tricyclic, saturated or unsaturated, and may be bridged, spiro, and / or fused. A cycloalkyl group may be substituted or unsubstituted. Unless specified otherwise, a cycloalkyl group typically contains from 3 to 12 ring atoms. In some instances a cycloalkyl group may contain 4 to 10 ring atoms (e.g., 4 ring atoms, 5 ring atoms, 6 ring atoms, 7 ring atoms, etc.). Representative examples include,but are not limited to, cyclopropyl, cyclopropenyl, cyclobutyl, cyclobutenyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, norbornyl, norbornenyl, bicyclo[2.2.1]hexane, bicyclo[2.2.1]heptane, bicyclo[2.2.1]heptene, bicyclo[3.1.1]heptane, bicyclo[3.2.1]octane, bicyclo [2.2.2] octane, bicyclo[3.2.2]nonane, bicyclo[3.3.1]nonane, and bicyclo[3.3.2]decane. Suitably, cycloalkyl groups are selected from cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups.

[0034] The term “room temperature” as used herein refers to a temperature of about 20°C.

[0035] Any reference to the measurement of a viscosity herein relates to a measurement that is performed at room temperature, unless the context indicates otherwise.

[0036] The term “about” when used herein in conjunction with a measurable value, such as transparency, turbidity or slump, encompasses reasonable variations of the value, for instance, to allow for experimental error in the measurement of said value.

[0037] For the avoidance of doubt, the expression “consists essentially of’ as used herein limits the scope of a feature to include the specified materials, and any other materials or steps that do not materially affect the basic and novel characteristics of that feature, such as, for example, minor impurities. The expression “consists essentially of’ embraces the expression “consisting of’.Universal Colorant Composition

[0038] The universal colorant composition of the invention is for use with both a water-based paint / coating and a solvent-based paint / coating. It is preferred that the colorant composition is for use with both a latex paint / coating and an alkyd paint / coating. The universal colorant composition of the present invention provides advantageous compatibility with both types of paint systems, is substantially non-separating or settling, and provides a tinted paint that exhibits a highly desirable rheological profile.

[0039] Additionally, or alternatively, the universal colorant composition is for use in the manufacture of paints or coatings that are substantially free of volatile organic compounds (VOCs).

[0040] Typically, the universal colorant composition is a universal low VOC colorant composition.

[0041] The universal colorant composition comprises, or may consist essentially of, a colorant and a viscosity stabilizing compound. In general, the universal colorant compositioncomprises, or may consist essentially of, a mixture of a colorant and a viscosity stabilizing compound.

[0042] The universal colorant composition comprises an effective amount of the viscosity stabilizing compound. An effective amount of the viscosity stabilizing compound is an amount for reducing or preventing a change in the viscosity of a base paint or base coating upon addition of the universal colorant composition to the base paint or the base coating. The effective amount may be an amount as defined below.

[0043] Generally, the universal colorant composition comprises an amount of the viscosity stabilizing compound of about 0.5 wt % to about 10.0 wt %, preferably about 1.0 wt % to about 7.5 wt %, more preferably about 1.5 wt % to about 5.0 wt % (e.g. about 3.0 wt %). For the avoidance of doubt, the % wt in this context refers to the total weight of the universal colorant composition.

[0044] The universal colorant composition may further comprise a surfactant, preferably a universal surfactant package.

[0045] The surfactant may be an alkyd-compatible surfactant or a latex-compatible surfactant. Such surfactants are known in the art.

[0046] When the universal colorant composition includes a universal surfactant package, then the universal surfactant package comprises, or may consist essentially of, an alkyd- compatible surfactant and a latex-compatible surfactant.

[0047] The universal colorant composition may comprise a carrier. The colorant and the viscosity stabilizing compound may each be dispersed, preferably dissolved, in the carrier.

[0048] When the universal colorant composition includes a surfactant, such as a universal surfactant package, then the surfactant or the universal surfactant package may be dispersed, preferably dissolved, in the carrier.

[0049] The universal colorant composition may include a hydrophobically modified alkali swellable emulsion (HASE) thickener.

[0050] Alternatively, the universal colorant composition may not include a hydrophobically modified alkali swellable emulsion (HASE) thickener. It may be preferable to include the hydrophobically modified alkali swellable emulsion (HASE) thickener in the base paint or base coating.

[0051] The universal colorant composition may further include one or more additional additives. The one or more additional additives may be a selected from a biocide, a humectant, an extender filler and a combination of any two or more thereof.

[0052] Additionally, or alternatively, the universal colorant composition may further comprise one or more components selected from a diluent; a dihydric alcohol or a polyhydric alcohol; a polyether; a defoaming agent; a dispersing agent and a combination of two or more thereof. It is preferred that the dispersing agent is a carboxyl-containing polymer (e.g. a poly aery late and / or a carboxyl-containing polyurethane).

[0053] The universal colorant composition of the invention is compatible with paints that use associative thickeners, even when the universal colorant composition includes a surfactant or a universal surfactant package. In other words, the paint or coating can maintain an acceptable viscosity after addition of the universal colorant composition.

[0054] An advantage of the universal colorant composition of the invention is that the composition is very stable and preferably do not require agitation during normal shelf life. This stability allows for the packaging of the universal colorant composition in a sealed container (e.g. a container that has no access port when connected to a dispenser) and allows for the accurate preparation of small tinted samples (e.g. from about 2 to 4 ounces (57 to 1 14 mLs). The samples can be prepared with a high degree of accuracy that will allow accurate color matching.

[0055] The inclusion of the viscosity stabilizing additive in the universal colorant composition may also avoid undesirable effects that are sometimes associated with the direct addition of a CVS additive to a base paint or base coating. Such undesirable effects include flocculation, pigment floating or other behaviours that affect the color tint, color strength and / or color uniformity of the applied paint.Colorant

[0056] A single colorant or a mixture of colorants may be included in the universal colorant composition of the invention.

[0057] Typically, the colorant is, or the mixture of colorants are, dispersed in the carrier of the universal colorant composition.

[0058] The colorant may comprise, or consist essentially of, a colored pigment, a dye, a tinting agent, or a metallic effect agent. Suitable colorants are known in the art.

[0059] Typically, the colored pigment has been dispersed in an aqueous or water-miscible medium by use of mechanical energy, i.e. grinding or shearing by means of dispersing equipment such as, for example, a ball mill and a sand mill. The dispersion process may be effected by the use of auxiliary compounds such as, for example, surfactants, wetting agents, water-miscible solvents, and dispersants, in addition to mechanical energy.

[0060] The colored pigment may be inorganic pigment (e.g. iron oxides, chromium oxide) or an organic pigment (e.g. phthalocyanine blue, carbon black).

[0061] Colorants are usually sold in concentrated form (typically 25% to 75% solids by weight) so that modest amounts can be used in a waterborne coating composition to provide a desired range of color intensities while not compromising the properties of the waterborne coating composition unduly.

[0062] Typical amounts of colorants which are used in architectural coatings are from 2 to 4 fluid ounces of colorant per gallon of base paint for light tint bases and pastels, from 4 to 8 fluid ounces of colorant per gallon of base paint for medium tint bases, and from 8 to 16 fluid ounces of colorant per gallon of base paint for deeptone tint bases. Of course, different colorants and mixtures thereof are frequently used to provide a wide latitude in color selection. Such colorants are frequently added to a base paint at the point-of-purchase of the colored paint, such as a paint store, followed by admixing the colorant and the waterborne coating composition by various means such as shaking the can of paint.Viscosity Stabilizing (VS) Compound

[0063] In principle, the viscosity stabilizing (VS) compound may have the same composition as a color viscosity stabilizing (CVS) additive known in the art. The difference in terminology (e.g. VS compound versus CVS additive) is used to differentiate the use or method of application of the VS compound in comparison to a (CVS) additive. The term “viscosity stabilizing compound” is synonymous with the term “viscosity stabilizing additive”.

[0064] The viscosity stabilizing compound may include polyethylene oxide polymer or a polyethylene oxide-polypropylene oxide copolymer, such as a polyethylene oxide polymer or a polyethylene oxide-polypropylene oxide copolymer as described hereinbelow.

[0065] The viscosity stabilizing (VS) compound may comprise, or consist essentially of, an ABLBA polymer and / or an ABCBA polymer. Each A is the same or different and is ahydrophobic group, each B is the same or different and is a hydrophilic polymer, L is a linking group and C is a hydrophobic low molecular weight difunctional radical.

[0066] In general, each A is a Cio to C36 oxy-radical. The C10 to C36 oxy-radical may include an alkyl group; an aryl group; an aryl-alkyl group; an alkyl-aryl group; a cycloalkyl group and a combination thereof. The Cio to C36 oxy-radical may, for example, include a phenolic group or tristyrylphenol.

[0067] Typically, each A (e.g. the oxy-radical) is derived from an alcohol, preferably an alcohol selected from a linear C10-C36 alcohol, a branched C12-C36 alcohol, a cyclic C10-C36 alcohol and a mixture of two or more thereof. It is preferred that each A is derived from a linear C10-C22 alcohol, a branched C12-C24 alcohol, a cyclic C10-C22 alcohol or a mixture of two or more thereof. More preferably, A is derived from a linear Cio-Cis alcohol, a branched C10-C18 alcohol, a cyclic Cio-Cis alcohol or a mixture of two or more thereof.

[0068] It is generally preferred that each A is derived from a linear C10-C36 alcohol, a branched C12-C36 alcohol or a mixture thereof, more preferably each A is derived from a linear C10-C24 alcohol, a branched C12-C24 alcohols or a mixture thereof, even more preferably each A is derived from a linear Cio-Cis alcohol, a branched C12-C18 alcohol or a mixture thereof.

[0069] In one example, each A is derived from 2-butyl-l -octanol, 2 -hexyl- 1 -decanol, 2-octyl- 1 -dodecanol, 2-isoheptyl-7-methyl-undecanol, 2-(2,4,4-trimethylbutyl)-6,8,8-trimethyl- nonanol, dodecanol, tetradecanol, hexadecanol, octadecanol, tristyrylphenol, 2,4,6-tris(l- phenylethyl)phenol, 2,6-bis(l-phenylethyl)phenol, a Geurbet alcohol having 14 carbon atom or a mixture of two or more thereof. It may be preferable that each A is derived from 2- hexyl-1 -decanol, tristyrylphenol, 2,4,6-tris(l-phenylethyl)phenol, 2,6-bis(l - phenylethyl)phenol or a mixture of two or more thereof. More preferably, each A is derived from 2,4,6-tris(l-phenylethyl)phenol, 2,6-bis(l-phenylethyl)phenol or a mixture of two or more thereof.

[0070] In another example, each A is derived from laurylalcohol, tetradecanol, hexadecanol, octadecanol or a mixture thereof.

[0071] In a further example, each A comprises dodecoxylate, tetradecoxylate or hexadecoxylate.

[0072] In yet another example, each A is a radical supplied by, e.g., carboxylic acids, amines, epoxides, ethers, isocyanates, and other moieties which are covalently bonded to B.

[0073] In the ABLBA polymer and the ABCBA polymer, each B includes a polyethylene oxide polymer or a polyethylene oxide-polypropylene oxide copolymer. The polyethylene oxide polymer and the polyethylene oxide -polypropylene oxide copolymer are collectively referred to hereinbelow as “polyoxyalkylene chains”.

[0074] The polyethylene oxide polymer typically has from about 25 to about 100 ethylene oxide repeat units, preferably from about 35 to about 90 (e.g. about 65) ethylene oxide repeat units, more preferably from about 45 to about 65 (e.g. about 50) ethylene oxide repeat units.

[0075] The polyethylene oxide-polypropylene oxide copolymer typically has a total number of repeat units ranging from about 25 to about 75 and up to about 10 propylene oxide units.

[0076] In general, the polyoxyalkylene chains have a number average molecular weight of up to about 4400, such as up to about 3500, preferably up to about 2500.

[0077] The polyoxyalkylene chains may have a number average molecular weight between about 1100 and about 4400, such as between about 1100 and about 3500 or about 2500 and about 4400.

[0078] In the ABLBA polymer, L is a difunctional moiety or a difunctional radical, such as a difunctional radical having 1 to 22 carbon atoms.

[0079] L may be derived from one or more linking units selected from a dianhydride unit, a diisocyanate unit and an ether linkage. It is preferred that L is a diisocyanate unit.

[0080] When L is a diisocyanate unit, then the diisocyanate unit may be selected from the group consisting of hexamethylene diisocyanate (HDI), trimethyl hexamethylene diisocyanate (TMDI), isophorone diisocyanate (IPDI), tetramethyl xylylene diisocyanate (TMXDI) and 4,4’-methylene bis(cyclohexylisocyanate). It is preferred that L is a hexamethylene diisocyanate unit.

[0081] For reactions using diisocyanate linking compounds, a catalyst such as an organo-tin or bismuth ester or an amine may be added to accelerate the reaction at the desired temperature. The reactions may be conducted under conditions to minimize branching and / or side reactions. In certain embodiments, reactants and / or conditions are selected to enhance branching, such as by the use of hexamethylene diisocyanate trimer, sold commercially as Desmodur N3600, a product of Bayer.

[0082] In one example, L is a linking unit that includes a dianhydride unit. The dianhydride unit may be derived from a compound (e.g. a dianhydride linking compound) including adianhydride moiety. The dianhydride unit may be derived from benzophenone tetracarboxylic dianhydride (BTD) or pyromellitic dianhydride (PM A). Each of these compounds react with hydroxyl bearing compounds to give the corresponding diester polymers. For reactions using dianhydride linking compounds, an amine such as triethylamine or DABCO may be used as a catalyst. The resulting polymers may have an anionic nature, which can be useful in some applications.

[0083] In another example, L is or includes an ether linkage or a difunctional moiety or difunctional radical having 1 to 22 carbon or equivalent atoms in a chain. Equivalent in this sense may be understood to mean di- and higher valency atoms which may bond with other atoms to form a chain. Such atoms may include carbon, oxygen, nitrogen and sulfur.

[0084] In the ABCBA polymer, C is a hydrophobic low molecular weight difunctional radical. Typically, C (e.g. the low molecular weight difunctional radical) has a number average molecular weight ranging from about 60 to about 1000 g / mole, such as from about 90 to about 1000 g / mole. Generally, the higher the number average molecular weight of C, the more insoluble the viscosity stabilizer additive. The molecular weight of C may be balanced against the molecular weight of B so as to create a material with the desired level of solubility.

[0085] Typically, C (e.g. the difunctional radical) may be derived from, or includes, a diol, such as a linear diol, a branched diol or a cyclic alkyl diol, which may optionally include a heteroatom, such as a heteroatom selected from O, N and S. The diol may be selected from ethylene glycol, propylene glycol, butanediol, 2-butyl-2-ethyl-l,3-propanediol and 1, 12- dodecanediol. When C is derived from or includes 1 ,2-dodecanediol, then A- and B- components may be adjusted to produce a polymer which can self-disperse in water.

[0086] C may include a water insoluble diol polymer, such as poly (tetrahydrofuran), poly(caprolactone), poly(tetrahydrofuran carbonate), poly (carbonate), poly(ethylene-co- 1 ,2- butylene), poly (propylene oxide) and poly(oxymethylene).

[0087] The ABLBA or ABCBA polymer may have a number average molecular weight below about 10,000 g / mole, such as less than 7,000 g / mole, preferably less than 4,500 g / mole.

[0088] In one example, the ABLBA or ABCBA polymer has a number average molecular weight of 4,500 g / mole to 10,000 g / mole.

[0089] A critical factor for viscosity stabilization may be the length of the polymer of the VS compound. While not wishing to be bound by theory, these stabilizers may function by a “loops and links” mechanism. In the absence of a sufficient number or concentration of surfaces and micelles, these small molecules may form flower-like micelles wherein all the hydrophobes of a polymer molecule reside in one micelle, or tails wherein one hydrophobe of a stabilizer molecule may participate in a micelle and the other is in the continuous phase. As the concentration of surfaces and micelles increases, such as by addition of surfactants to the paint system through, for example, addition of a universal colorant composition, and the distance between them decreases, these stabilizer molecules may begin to bridge between micelles (“micellar bridging”) and surfaces and in so doing may form a network.

[0090] The ABLBA copolymer is typically synthesized from an AB ethoxylate by reacting the A compound and the monomeric components which comprise the B components in a basic solution or in the presence of a metal catalyst. The AB ethoxylate may then be reacted with a linking compound L.

[0091] In one example, the AB ethoxylate has a number average molecular weight below about 5,000 g / mole.

[0092] In another example, the AB ethoxylate has a number average molecular below about 2,500 g / mole.

[0093] In some examples, the AB ethoxylate has a number average molecular weight between about 1200 g / mole and about 5,000 g / mole.

[0094] The block co-polymer ABCBA is typically synthesized using an ethoxylated alcohol for the AB-blocks, a diisocyanate for a linking unit, and a diol as the C-block. In an example, the ratio of these components (ethoxylated alcohol, diisocyanate, and diol) ranges from about 2:2:0.9 to 2:2: 1.2. In some examples, the ratio of components is about 2:2: 1.

[0095] In an example of the ABCBA copolymer, the AB block includes alkyl, aryl or alkylaryl ethoxylates, of the form RO-(CH2CH2O)n-H, a diisocyanate, and a diol C, where RO- (CH2CH2O)n-H contributes both the A component and the B component.

[0096] In one example of the ABLBA polymer, each A is derived from 2-hexyl-l -decanol, each B includes a polyethylene oxide having about 40 to 60 (e.g. about 50) ethylene oxide units, and L is derived from hexamethylene diisocyanate.

[0097] In another example of the ABLBA polymer, each A is a lauryl alkoxy group, each B is a polyethylene oxide having about 50 to about 70 ethylene oxide units, and L is derived from hexamethylene diisocyanate.

[0098] In a further example of the ABLBA polymer, each A is derived from dodecanol, each B is a polyethylene oxide having about 50 to about 70 ethylene oxide units, and L is derived from hexamethylene diisocyanate.

[0099] The ABCBA polymer is typically an ABCBA block copolymer.

[0100] The ABCBA block copolymer may include at least two linking units L, one each between B and C, i.e. the polymer is an ABLCLBA polymer. Each L may be the same or different and comprises a polyfunctional linking radical having 2 to 5 valences, preferably a difunctional linking radical.

[0101] In the ABLCLBA polymer, each of A, B, L and C are as defined herein.

[0102] When the polymer is an ABLCLBA polymer, then each A may be derived from a linear C10-C36 alcohol, a branched C12-C36 alcohol, a cyclic C10-C36 alcohol or a mixture of two or more thereof.

[0103] In one example of the ABLCLBA polymer, each B may comprise a polyethylene oxide polymer or a polyethylene oxide-polypropylene oxide copolymer, such as defined above; C may be derived from, or include, a diol, such as a linear diol, a branched diol or a cyclic alkyl diol, which may optionally include a heteroatom, such as a heteroatom selected from O, N and S; and each L may be derived from one or more linking units selected from a dianhydride unit, a diisocyanate unit, an ether linkage and a difunctional moiety or difunctional radical having 1 to 22 carbon atoms.

[0104] In another example of the ABLCLBA polymer, each B may comprise poly(ethylene glycol); C may be derived from a diol selected from ethylene glycol, propylene glycol, and 1,2-dodecanediol; and each L may be derived from a dianhydride unit or a diisocyanate unit.

[0105] In a further example of the ABLCLBA polymer, each B may comprise poly(ethylene glycol); C may be derived from a diol selected from poly (tetrahydrofuran), poly(caprolactone) and poly (carbonate); and each may be derived from a dianhydride and a diisocyanate unit.

[0106] In general, L comprises one or more of the following: a urethane linking unit; an ester linking unit; an amide linking unit; a urea linking unit; an ether linkage; or other difunctionalmoiety or difunctional radical having 1 to 22 carbon atoms. In some embodiments, the linking units comprise urethane links obtained from compounds selected from the group consisting of hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, isophorone diisocyanate, tetramethyl xylylene diisocyanate, and 4,4-methylene bis (cyclohexylisocyanate) .Base Paint or Base Coating

[0107] The base paint or base coating may be water-based (e.g. a water-based paint / coating) or solvent-based (e.g. a solvent-based paint / coating). It is preferred that the base paint or base coating is a latex paint / coating or an alkyd paint / coating.

[0108] Aqueous coatings with excellent in-can stability and application properties that simultaneously provide excellent color viscosity stability and excellent color acceptance may be formulated by using a universal colorant composition comprising a viscosity stabilizing compound, optionally with minor amounts of select hydrophobically modified alkali swellable thickeners (HASEs).

[0109] The base paint or the base coating may include a hydrophobically modified alkali swellable emulsion (HASE) thickener, such as described herein below. The HASE thickener may, for example, be the reaction product of vinyl acetate, methyl methacrylate, methacrylic acid and tristyrylphenol polyethoxy ethyl methacrylate.

[0110] The base paint or base coating typically includes a total amount of about 0.02 wt % to about 0.5 wt % of the HASE thickener, preferably about 0.02 wt % to about 0.2 wt %, such as about 0.1 wt % to about 0.2 wt %. The base paint or coating includes a sufficient amount of a HASE thickener to improve the color acceptance properties of the paint.

[0111] In some embodiments, the paint system includes about 0.02 wt % to about 0.5 wt % as active polymer of the hydrophobically modified alkali swellable emulsion thickener. In some embodiments, In some embodiments, a hydrophobically modified alkali- swellable emulsion thickener is comprised of a tristyrylphenol-containing monomer.

[0112] The base paint or base coating may further comprise a resin. The resin may comprise one or more of the following: a vinyl acrylic resin, a vinyl acetate ethylene resin, an acrylic resin and a styrene acrylic resin.

[0113] Typically, the resin has a particle size greater than 200 nm. Alternatively, the resin may have a particle size less than 200 nm.

[0114] The resin may be a film forming binder resin. The film forming binder resin may include an emulsion resin, a water dispersible resin and / or a water soluble resin.

[0115] A film forming binder resin is the actual film forming component of a paint or coating. Binders can be categorized according to drying, or curing mechanism. The four most common are simple solvent evaporation, oxidative crosslinking, catalyzed polymerization, and coalescence.

[0116] The base paint or coating may include a resin binder. The resin binder may be water dispersible resin, such as a water dispersible alkyd or a water dispersible polyurethane; a water soluble resin; an emulsion resin, such as is typically used to manufacture latex paints; a hydrophobic resin, such as an acrylic resin, a styrene acrylic resin or a styrene resin; a hydrophilic emulsion resin, such as a vinyl acrylic resin or a vinyl acetate ethylene resin.

[0117] In general, the resin and / or resin binder has a particulate form, wherein the particles have a substantially spherical shape. A substantially spherical particle is defined as a particle having a roundness of at least 0.7 and sphericity of at least 0.7, as measured by the use of a Krumbien / Sloss chart using the experimental procedure recommended in International Standard ISO 13503-2, “Petroleum and Natural Gas Industries — Completion Fluids and Materials — Part 2: Measurement of Properties of Proppants Used in Hydraulic Fracturing and Gravel-Packing Operations” (First Edition, 2006), Section 7, for the purposes of this disclosure.

[0118] Typically, the particle size of the particles may be greater than about 200 nm, such as from about 220 nm to about 650 nm. These particles are relatively large and may have a low surface area.

[0119] Alternatively, the particle size of the particles may be less than about 200 nm, such as from about 80 nm to about 180 nm. These particles are relatively small and may have a high surface area.

[0120] In some examples, the resin has a multilobe shape.

[0121] Representative resins may include Optive 130 (BASF, acrylic, 160 nm), UCAR 300 (Dow, vinyl acrylic, 260 nm), UCAR 625 (Dow, acrylic, 340 nm), Rhoplex ML-200 (Rohm & Haas, acrylic, 590 nm multilobe), and Neocryl XK-90 (DSM Neoresins, acrylic, 90 nm).

[0122] The base paint or base coating may include a diluent. Suitable diluents may include but are not limited to water, coalescing solvents, water miscible solvents, and other liquids which are used to reduce the concentration of the non-volatile materials use in the base paint.

[0123] In general, the base paint or the base containing includes at least one associative thickener.

[0124] Associative thickeners are water soluble, water dispersible, or water swellable polymers that have chemically attached hydrophobic groups.

[0125] The associative thickener may be a condensation polymer (e.g. a condensation polymer associative thickener). The condensation polymer may include a polyether polyurethane, a polyether polyol, a polyether polyacetal or a polyether aminoplast.

[0126] In one example, the associative thickener has a composition of a hydrophobically modified polyether polyurethane. In another example, the associative thickener has a composition of a hydrophobically modified polyether polyacetal. In yet another example, the associative thickener has a composition of hydrophobically modified polyether.

[0127] The associative thickener may include (i) a nonionic hydrophobically modified material, such as polyether associative thickener and / or a polyurethane associative thickener, or (ii) an ionic associative thickener, such as an ionic associative thickener selected from a hydrophobically modified alkali swellable (or soluble) emulsion (HASE), a hydrophobically modified hydroxyethyl cellulose and a mixture of two or more thereof.

[0128] The number average molecular weight of the associative thickener is typically from about 10,000 to about 500,000 g / mole, preferably from about 10,000 to about 50,000 g / mole. The value of the number average molecular weight may depend on the chemical type of associative thickener.

[0129] In an example, the number average molecular weight of the associate thickener is from about 100,000 to about 300,000 g / mole.

[0130] In another example, the number average molecular weight of the associate thickener is from 400,000 to about 800,000 g / mole.

[0131] The base paint or base coating may include two associative thickeners. The two associative thickeners may be independently selected from a polyether polyurethane, a polyether polyol, a polyether polyacetal and a polyether aminoplast.

[0132] In one example, the two associative thickeners may both be a polyether polyurethane. In another example, the two associative thickeners may both be a polyether polyacetal. In yet another example, one (e.g. a first) associative thickener is a polyether and the other (e.g. a second) associative thickener is a polyether polyurethane. Representative associative thickener pairs may include Rohm & Haas Acrysol RM 825 / RM 2020 NPR, Rohm & Haas Acrysol SCT 275 / RM 2020 NPR, Aquaion NLS 200 / NHS 300, Elementis RHEOLATE 255 / 350 and Cognis DSX 1514 / DSX 3075.

[0133] Typically, the base paint or the base coating includes a total amount of about 0.05 wt % to about 5.0 wt % of the associative thickener, such as about 0. 1 wt % to about 3.0 wt %, preferably about 0.2 wt % to about 1.0 wt %.

[0134] The base paint or the base coating may include a high shear associative thickener or a a mid-shear associative thickener. The terms high and mid shear are relative and are meant to indicate that the thickeners are particularly useful for either increasing the high shear viscosity of a paint or coating or the mid shear viscosity of a paint or coating. High shear viscosity of a paint or coating is typically measured at 10,000 sec-1(the so-called ICI viscosity), which is intended to represent the viscosity of the paint or coating during typical brush and roller application conditions. Mid shear viscosity relates to the in-can appearance and is typically measured in Krebs units (KU) using a Stormer viscometer.

[0135] When the resin has a particle size less than about 200 nm, then the base paint or base coating may include a high shear thickener. When the resin has a particle size greater than about 200 nm, then the base paint or the base coating may include a high shear thickener and a mid-shear thickener.

[0136] The base paint or base coating may include one or more additional components selected from a wetting agent, a surfactant, a solvent, a pH adjusting agent, an anti-skinning agent, a pigment, a filler, a humectant, an anti-freeze, a drier, and a crosslinking agent.Alkali Swellable Emulsion Thickeners

[0137] The base paint, base coating or the universal colorant composition may include a hydrophobically modified alkali swellable emulsion (HASE) thickener.

[0138] In one example, the base paint or the base coating includes a HASE thickener and the universal colorant composition does not include a HASE thickener. In another example, the universal colorant composition includes a HASE thickener and the base paint or the base coating does not include a HASE thickener.

[0139] Alkali swellable emulsions (ASEs) are well known in the art.

[0140] An ASE is typically an addition copolymer of vinyl unsaturated monomers, such as vinyl esters and / or (meth)acrylate monomers. Such ASEs may be comprised of about 25 wt % to about 50 wt % of one or more acidic monomers, such as, for example, acrylic acid, methacrylic acid and itaconic acid.

[0141] ASEs may be supplied as low viscosity emulsions. However, upon neutralization of the acidic functions, the emulsion particles may swell and ultimately untangle due to ionic repulsion of the neutralized acid moieties. The great expansion in volume and further entanglement of the high molecular weight polymer chains may lead to thickening of the aqueous system into which they are formulated.

[0142] HASEs may be similar to ASEs, except that they may additionally include of one or more monomers having a hydrophobic radical attached to a hydrophilic polymer bridging the polymer backbone and the hydrophobic radical. Examples of such monomers may include but are not limited to lauryloxy polyoxyethyl ethyl acrylate, lauryloxy polyoxyethyl ethyl methacrylate, stearyloxy polyoxyethyl ethyl acryl ate, stearyloxy polyoxyethyl ethyl methacrylate, tristyrylphenol polyoxyethyl ethyl acrylate, and tristyrylphenol polyoxyethyl ethyl methacrylate. Such hydrophobe-containing monomers are commonly known as surfactant modified monomers, since the alcoholic radical of the vinyl monomer is similar to a nonionic surfactant in structure.

[0143] One example of a suitable HASE thickener is RHEOLATE™ 425 from Elementis Specialties, Inc., which comprises tristyrylphenol polyoxyethylene ethyl methacrylate. Another example may include an emulsion polymer of ethyl acrylate, methacrylic acid, methyl methacrylate and Cl 6 / CI 8 polyoxyethylene methacrylate.

[0144] In an example, the HASE thickener includes a substituted phenol hydrophobe. In another example, the HASE thickener includes tri styrylphenol as a hydrophobe.

[0145] The HASE thickener may be a TSP-HASE thickener.

[0146] A HASE thickener with a tristyrylphenol modified monomer (TSP-HASE) may be used. Such a monomer may include an average of about 15 to about 50 mols of ethylene oxide units joining a tristyrylphenoxy radical to the TSP-HASE polymer chain. Such monomers include but are not limited to tristyrylphenol polyoxyethylene ethyl acrylate, tristyryl phenol polyoxyethylene ethyl methacrylate, and 3 -tristyrylphenol polyoxyethylene propene, each having an average of about 15 to about 50 repeat units of ethylene oxide.Commercial embodiments of these monomers may be mixtures comprising mono-, di- and tri-styrylphenyl radicals and / or these monomers may be comprised of a distribution of ethylene oxide repeat units.

[0147] The TSP-HASE thickener includes tristyrylphenol modified monomer having ethylene oxide units joining a tristyrylphenyl radical to the HASE backbone polymer chain; or tristyrylphenol modified monomer having propylene oxide units joining a tristyrylphenyl radical to the TSP-HASE backbone polymer chain; or tristyrylphenol modified monomer having both ethylene oxide units joining a tristyrylphenyl radical to the TSP-HASE backbone polymer chain and propylene oxide units joining a tristyrylphenyl radical to the TSP-HASE backbone polymer chain; or tristyrylphenol modified monomer having both ethylene oxide and propylene oxide units as random or block copolymers joining a tristyrylphenyl radical to the TSP-HASE backbone polymer chain.

[0148] In an example, the TSP-HASE thickener is the reaction product of vinyl acetate, methacrylate, methacrylic acid and tristyrylphenol polyethoxy ethyl methacrylate. The preparation of a TSP-HASE is described in EP0705852.

[0149] The HASE thickener may be added to the base paint at any stage, such as before addition of the universal colorant composition or as part of the universal colorant composition.

[0150] When the HASE thickener is added directly to the base paint or base coating (e.g. before addition of the universal colorant composition), then the HASE thickener may be added as an emulsion or as a dry powder. The HASE thickener may be added at any point during the base paint or base coating making process including during the grind or the letdown phases or to the fully letdown base paint or coating.

[0151] The HASE thickener may be added to the base paint, base coating or the universal colorant composition as an emulsion, as a preneutralized or partially neutralized dispersion.

[0152] The HASE thickener may be activated by addition of alkali at any point. Typical alkalis include alkali metal hydroxides and carbonates and organic amines. In most instances, however, the base paint contains sufficient alkali to neutralize and activate the HASE thickener.Paint System or Coating System

[0153] The invention provides a paint system or a coating system. The system includes a base paint or base coating; and the universal colorant composition for addition to the base paint or the base coating. For the avoidance of doubt, the universal colorant composition is separate to the base paint or base coating.

[0154] An aspect of the invention provides a water-borne paint system having improved viscosity stability and color acceptance properties.

[0155] Color acceptance and the value of AE of a finished colored aqueous formulation may be determined using the rub-up test. The AE measurement test is often called a “test of rubbing with the finger,” known to persons skilled in the art by the term “rub ups.” This test consists of applying the formulation of the colored finish paint to be tested onto a test chart, waiting until the paint becomes tacky, and then applying shear stress by rubbing, with the finger, the still viscous film of paint, for 60 seconds.

[0156] After the film dries, the colorimetric difference between the shear-stressed area (rubbed area) and the non-shear-stressed area (area of the non-rubbed film), determined by measuring CIELAB color coordinates L* a* b*, makes it possible to evaluate (value of AE) whether or not the paint composition tested has a good pigmentary compatibility.

[0157] It is desired that the paint composition has a AE of less than 0.8, preferably less than 0.5, more preferably negligible AE.Uses and Methods

[0158] The method of manufacturing a finished paint or coating includes mixing a universal colorant composition with a base paint or a base coating. The way in which the universal colorant composition and the base paint / coating are mixed are conventional.

[0159] The invention also relates to reducing or preventing a change in the viscosity of a base paint or base coating upon addition of the universal colorant composition to the base paint or the base coating. The change in viscosity is typically a loss in viscosity.

[0160] By loss in viscosity, we mean that the Stormer viscosity of a base paint or base coating of 90-110 Krebs Units (KU) changes by less than about 10 KU, preferably less than about 5 KU.

[0161] The Stormer viscosity changes are the differences between the Stormer viscosities of untinted, equilibrated base paints or coatings and the equilibrated paint systems containing the colorant(s). Base paints and paint systems are allowed to equilibrate in a constanttemperature environment (typically 20-30° C.) for periods of from typically 4 to 24 hours. The paints are not disturbed while equilibrating.

[0162] The entire disclosure of each document cited herein is hereby incorporated herein by reference. All references cited in this disclosure are incorporated by reference to the same extent as if each reference had been incorporated by reference in its entirety individually.

[0163] The citation and incorporation of patent documents herein is done for convenience only and does not reflect any view of the validity, patentability, and / or enforceability of such patent documents.

[0164] A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, other embodiments are within the scope of the following claims.

[0165] All headings and sub-headings are used herein for convenience only and should not be construed as limiting the invention in any way.

[0166] The use of any and all examples, or exemplary language (e.g. “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise paragraphed. No language in the specification should be construed as indicating any non-paragraphed element as essential to the practice of the invention.

Claims

CLAIMS1. A universal colorant composition for use with both a water-based and a solvent-based paint or coating, the universal colorant composition comprising: a colorant; and a viscosity stabilizing compound.

2. The universal colorant composition according to claim 1, wherein the viscosity stabilizing (VS) compound comprises an ABLBA polymer, wherein each A is the same or different and is a hydrophobic group, each B is the same or different and is a hydrophilic polymer, and L is a linking group.

3. The universal colorant composition according to claim 2, wherein L is selected from one or more of the following linking units: a dianhydride unit, a diisocyanate unit and an ether linkage.

4. The universal colorant composition according to claim 2 or claim 3, wherein L is a diisocyanate unit, preferably the diisocyanate unit is selected from the group consisting of hexamethylene diisocyanate (HDI), trimethyl hexamethylene diisocyanate (TMDI), isophorone diisocyanate (IPDI), tetramethyl xylylene diisocyanate (TMXDI) and 4, ’methylene bis(cyclohexylisocy anate) .

5. The universal colorant composition according to any one of claims 1 to 4, wherein the viscosity stabilizing (VS) compound comprises an ABCBA polymer, wherein each A is the same or different and is a hydrophobic group, each B is the same or different and is a hydrophilic polymer, and C is a hydrophobic low molecular weight difunctional radical.

6. The universal colorant composition according to claim 5, wherein C has a number average molecular weight ranging from about 60 to about 1000.

7. The universal colorant composition according to claim 5 of claim 6, wherein C is derived from a diol.

8. The universal colorant composition according to any one of claims 2 to 7, wherein each A is a C 10 to C36 oxy-radical.

9. The universal colorant composition according to any one of claims 2 to 8, wherein each A is derived from an alcohol selected from a linear C10-C36 alcohol, a branched C12-C36 alcohol, a cyclic C10-C36 alcohol and a mixture of two or more thereof.

10. The universal colorant composition according to any one of claims 2 to 9, wherein each A is derived from 2 -hexyl- 1 -decanol, tristyrylphenol, 2,4,6-tris(l-phenylethyl)phenol, 2,6- bis(l-phenylethyl)phenol or a mixture of two or more thereof.

11. The universal colorant composition according to any one of claims 2 to 10, wherein each B includes a polyethylene oxide polymer or a polyethylene oxide-polypropylene oxide copolymer.

12. The universal colorant composition according to claim 11, wherein the polyethylene oxide polymer has from about 25 to about 100 ethylene oxide repeat units.

13. The universal colorant composition according to claim 11, wherein the polyethylene oxide-polypropylene oxide copolymer has a total number of repeat units ranging from about 25 to about 75 and up to about 10 propylene oxide units.

14. The universal colorant composition according to any one of claims 11 to 13, wherein each of the polyethylene oxide polymer and the polyethylene oxide-polypropylene oxide copolymer has a number average molecular weight between about 1100 and about 4400.

15. The universal colorant composition according to any one of claims 1 to 14, further comprising a hydrophobically modified alkali swellable emulsion thickener.

16. The universal colorant composition according to any one of claims 1 to 15, which further comprises a surfactant.

17. The universal colorant composition according to any one of claims 1 to 16, which further comprises a carrier.

18. The universal colorant composition according to any one of claims 1 to 17, which further comprises one or more additional additives selected from a biocide, a humectant, an extender filler and a combination of any two or more thereof.

19. A paint or coating system comprising:(i) a base paint or base coating; and(ii) the universal colorant composition according to any one of claims 1 to 18 for addition to the base paint or the base coating.

20. A method of manufacturing a finished paint or a finished coating comprising: mixing the universal colorant composition according to any one of claims 1 to 18 with a base paint or a base coating.