MXPA00002702A - Method of improving viscosity stability of aqueous compounds - Google Patents

Abstract

A method of improving the viscosity stability of an aqueous composition by the addition to the aqueous composition of a mixture of at least one multiphobe and at least one monophobe is disclosed. The method is particularly useful for stabilizing the viscosity of an aqueous composition containing at least one associative thickener, when surfactants or additives containing surfactants, such as for example colorants, particularly at high levels, are added to the aqueous composition.

Description

METHOD FOR IMPROVING STABILITY OF VISCOSITY IN AQUEOUS COMPOSITIONS This invention relates to a method for improving the viscosity stability in aqueous compositions. The method of this invention is particularly applicable to improving viscosity stability in aqueous compositions containing associative thickeners. Associative thickeners are water-soluble or water-swellable polymers, which have chemically bound hydrophobic groups. These associative thickeners operate to thicken systems to which they have been added by non-specific associations, such as adsorption on surfaces and aggregate in solutions similar to micellization, between hydrophobic groups in the thickener molecules and parts on the other components in the system, similar to the non-specific associations of conventional surfactants. Since the hydrophobic association, exhibited by the associative thickeners, is not specific, it is greatly influenced by the presence of tensidants and organic solvents miscible in water. The hydrophobes of the surfactants may compete at the adsorption sites on the particle surfaces, and may obstruct or increase the associations between the hydrophobic thickeners, depending on the lipophilic / hydrophilic balance ("HLB") of the surfactant. Once the associative thickener is completely desorbed from a particle, such as a latex particle, it can behave as a nonabsorbent thickener and the latex flocculates by the volume restriction process. A classic problem in paints containing associative thickeners is a drop in the average cut viscosity (from Krebs-Stormer), when dyes containing high levels of the surfactant are added. This is especially problematic when the paint is going to be dyed in a deep tone, due to the high level of surfactant that generally accompanies the dye. The dyes are added to paints in units of ounces of dye per gallon of paint (hereinafter abbreviated as "oz" / gal ") or in grams of dye per liter of paint (g / 1). ), typically contain no more than 4 oz / gal (29.96 g / 1) dye, and mid-tone paints typically contain more than 4 oz / gal (29.96 g / 1) up to 8 oz / gal (59.92 g / 1) Deep-tone paints typically contain 8 oz / gal (29.96 g / 1) up to 12 oz / gal (89.88 g / 1) dye.

Generally, it is possible to formulate a clear dye base with a sufficiently high average cut viscosity, that the dyes added thereto will not decrease the viscosity to an unacceptable degree. Associative thickener combinations have been found that are less sensitive to dye addition than single thickeners alone, in some cases. However, none of these solutions is completely satisfactory, because they require a tedious reformulation, added cost or both, particularly in deep-tone paints. The method and mixture containing a multiflow and a monophore of the present invention provides a solution to these problems. Combinations of multi-phobes, such as an associative thickener, with a monophobe, such as a surfactant, are known in many conventional aqueous compositions, such as, for example, in paints, adhesives and other coating compositions. For example, EP-A-0 773 263 discloses a substantially anhydrous composition, which contains a solid associative thickener and one or more surfactants and notes, specifically on page 3, lines 47-48, that the mixture described therein it is inferior in pigmented coating compositions. Tarng et al., In "Aqueous Solutions Associated Model", Adv. Chem. Ser., Volume 48, pages 305-341, describes mixtures of the HEUR associative thickener, with low molecular weight surfactants, ie surfactants of the anionic type (sodium dodecylbenzene sulfonate, Molecular Weight = 348) or nonionic type (C13H27 (OCH2CH2) 9OH, Molecular Weight = 596). None of these conventional aqueous compositions utilizes a mixture of a selected multiflow component and a selected monophobic component, wherein the ratio of the molecular weight of the monobore to the molecular weight of the multiflow is relatively large, as compared to similar components in conventional aqueous systems. The unique blend of the invention provides a solution to a serious problem, which was mentioned in the paint industry for more than 20 years.

Brief Description of the Drawings Figure 1 is a protection of the viscosity drop KU) of initial KU = 90 in the addition of dye vs. the level of the phthalo blue colorant, added, for a paint containing a HASE associative thickener, with or without the mixture of the invention.

Figure 2 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HEUR associative thickener, with and without the mixture of the invention. Figure 3 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HEUR associative thickener, without the mixture of the invention (control), without the monophobic component of the mixture of the invention (comparative) and with the mixture of the invention. Figure 4 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HAS associative thickener, without the mixture of the invention (control) and without the multiphobic component of the mixture of the invention (comparative). Figure 5 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HASE associative thickener, and various Mn ratios. of the monophobic hydrophilic segment: hydrophilic multiflow segment (comparative and mixtures of the invention). Figure 6 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HASE associative thickener, (control) and mixtures containing multi-phobic hydrophilic segments having several Mn (comparatives and mixtures of the invention). Figure 7 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HASE associative thickener, (control) and several mixtures containing monophobes and multiphobes, where the hydrophobic groups vary in size (comparatives and mixtures of the invention). Figure 8 is a projection of the viscosity drop (KU) of the initial KU = 90 in the addition of dye versus the level of the added phthalo blue dye, for a paint containing the HEUR associative thickener, (control) and several mixtures containing monophobes and multiphobes synthesized by free radical polymerization (mixtures of the invention.

Disclosure of the Invention The invention is directed to a method for improving the viscosity stability of an aqueous composition, by adding to the composition a mixture containing: a.) At least one multiflow, this multiflow contains at least one hydrophilic segment and at least two hydrophobic segments; in which the number average molecular weight / Mn) of the multi-buff hydrophilic segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and b.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in that the hydrophobicity of the hydrophobic monophobic segment is sufficient to form non-specific hydrophobic associations. The method of the invention is useful for stabilizing the viscosity of an aqueous composition containing at least one associative thickener. It is particularly useful in stabilizing the viscosity of an aqueous composition containing at least one associative thickener, when surfactants or additives containing surfactants, such as, for example, dyes, particularly at high levels, are added to the aqueous composition. All of the number average molecular weight values (referred to herein as "Mn") were determined by high pressure liquid chromatography (referred to herein as "HPLC"), unless otherwise specified. "KU", as used herein, means Krebs units and is a measure of the average cut viscosity, as measured by the Kreb-Stormer viscometer. "Stability of viscosity", as used herein, means the ability of an aqueous composition to resist a change in viscosity, as measured in KU units, by the addition of a surface active agent or a composition containing a surfactant. A preferred viscosity stabilizer for latex paints, should provide changes in KU viscosity of less than about 10 units in the addition of up to 12 oz / gal (90 g / 1) of dye. A more preferred viscosity stabilizer for latex paints, should provide changes in KU viscosity of less than about 5 units, in the addition of up to 12 oz / gal (90 g / 1) of dye. , the prefix of "(met) acril-" means both the methacryl and acryl version of any monomer.As used herein, the term "aqueous composition" means a composition that is predominantly provided in water, rather than in an organic solvent However, it is considered that a smaller amount of organic solvent may be included in the composition and that the composition, however, will meet the definition of "aqueous composition." As used herein, the term "paint" "basic" means a white paint to be colored or dyed.To enable this white paint to be colored or stained in several grades, the basic paint will contain several levels of titanium dioxide, to allow the suitable coloring or dyeing As used herein, the phrase "hydrophobic equivalent" means a portion that is quantitatively equivalent in hydrophobicity to its hydrocarbon analogue, including hydrocarbons substituted by heteroatoms and siloxane analogs. The quantitative measure of hydrophobicity is described in Chapters 4 and 5 of C.

Hansch and A. Leo, in Exploring QSAR Fundamental and Applications in Chemistry and Biology, (Washington, D.C., American Chemical Society, 1995). Multiphobes useful in the method of the invention are compounds containing at least one hydrophilic segment and at least two hydrophobic segments. The multiflow is preferably a diphobe. The Mn of the multiflow hydrophilic segment is greater than 2,000, preferably from 3,000 to 20,000 and more preferably from 4,000 to 10,000. The hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations. Preferably, the hydrophobic multi-phobic segments contain a hydrocarbon portion having at least 8 carbon atoms or their hydrophobic equivalent. The monophobes useful in the method of the invention are compounds that contain at least one hydrophilic segment and only one hydrophobic segment. The monophobes may contain more than one hydrophilic segment, so the monophobic may have the hydrophilic segment structure - hydrophobic segment - hydrophilic segment. The monophobes of the invention can be nonionic, anionic, cationic or amphoteric. The Mn of the monophobic hydrophilic segment is at least half of the Mn of the multi-buff hydrophilic segment. Preferably, the Mn of the monophobic hydrophilic segment is greater than 2,000. The hydrophobicity of the hydrophobic monophobic segment is sufficient to form non-specific hydrophobic associations. A variety of conventional techniques can be employed to determine whether the hydrophobicity of the hydrophobic segment of either the mono or multipurpose is sufficient to form non-specific hydrophobic interactions. These techniques generally show a drastic change in the physico-chemical quantities of the monophobic or multiflow material, above and below the critical concentration of micelles. Such techniques include, without limitation, scattering of light (at 90 ° of incident light), osmotic pressure, turbidity, solubilization, magnetic resonance, surface tension, equivalent conductivity and self-diffusion. If the hydrophobic segment exhibits this type of behavior (ie, a drastic change in the physico-chemical quantity), then the hydrophobicity and its hydrophobic segment is sufficient to form nonspecific interactions. Examples of the chemical structure of the diphobes (I) and the monophobes (II), useful in the invention, are: (I) R - X - WS - X '- R' (II) R - X - WS - X ' - Z The R and R 'represent the hydrophobic segments that are sufficient to form the non-specific hydrophobic associations and may be the same or different. Suitable parts of R and R 'include hydrocarbons having at least 8 carbon atoms, or the hydrophobic equivalent of at least 8 carbon atoms, such as aliphatic (linear or cyclic) hydrocarbons, aromatic, or a combination of aliphatic and aromatic (such as alkylphenyl, fluorinated versions of these structures and other hydrophobic functionalities, such as siloxanes.) Suitable Z parties include hydrocarbons having no more than 7 carbon atoms, or hydrophobic equivalents having no more than 7 carbon atoms. carbon, preferably when Z = H or -CH3 WS represents the hydrophobic segment and is a polymeric part soluble in water.WS suitable are polyethers, which include polyethylene oxide (also known as polyethylene glycol), and oxide copolymers. of ethylene with comonomers, such as propylene oxide and butylene oxide, both of which can be randomly incorporated n Blocks Other suitable monomers, such as epoxides and α-olefins with at least 10 carbon atoms (e.g., 1-decene epoxide) result in WS having pendant hydrophobic groups of at least 8 carbon atoms, in this case, RX-WS-X '-R', contains more than two hydrophobic segments. It should be appreciated that the composition of the substituents of R or R1 and WS will depend on the chemical composition of the reagents used to form the components of the mixture of the invention., For example, when WS is polyethylene oxide, the reaction of the terminal hydroxyl functionality with the diisocyanate, followed by the reaction of the newly formed isocyanate end groups with an alcohol, leads to R, R 'or Z which include hydrophobic contributions of both diisocyanate and alcohol. X and X 'represent the connection link groups and may be the same or different. Suitable links include: -O- (ether); -0-C (0) -NH- (urethane); -O-CO- (ester); -NY- (imino); -NY-C (O) - (amide; -NY-C (O) -NH- (urea); -S- (sulfur); -O-Si- (siloxane); where Y = R, R 'or Z A mixture of different types of multi-phobes can be used for the multi-phobic component of the mixture of the invention, with the condition that each different type of multi-phobic individually meets the definition of the multi-phobic.Similarly, a mixture of different types of monophobes can be used for the monophobic component of the mixture of the invention, with the proviso that each different type of monophore individually complies with the definition of the monophobic Suitable multipurpose include those diphobes disclosed in US-A-3,770,684, which includes analogs prepared by the reaction of 1 mole of polyethylene oxide with 2 moles of R-NCO, to form a urethane with urethane as the connecting link Other suitable multi-fobs include those described in GB-A-1, 358, 430. These materials have the structure: RO- (CH2CH20) n - A- (OCH2C H2) n-OR and are synthesized by connecting two nonionic surfactants, hydroxyl-terminated, with a diiscianate (A). Suitable monophobes include those formed by the ethoxylation of hydrophobic alcohols or amines, as well as those prepared by the reaction of Z-0- (CH2CH20) m -H, (where Z? H) with the. R-NCO. The mixture of the invention can be prepared by synthesizing the monophobic and multiflow components separately, and then combining. The mixture of the invention can also be prepared in a single preparation. Appropriate approaches include modifying the synthetic routes described in US-A-3, 770, 684 and GB-A-1, 358, 430 by loading the reagents at the appropriate molar ratios and using less than two moles of the hydrophobe, on average , per molecule of the final product, to produce a mixture of monophobic and multiphobic, rather than pure multipurpose. For example, the blends of the invention shown in Example 8 were prepared by reacting 1 mole of the polyethylene oxide with 1 mole of C1.4-NC0, to form a mixture of monophobic and multi-buff in a molar ratio of 2: 1. Example 3 illustrates the preparation of analogues with Mn of 10,000 of this material. An equivalent mixture of monophobic and multiphobic, containing both hydrophilic segments of polyethylene oxide (Mn = 10,000 = can be prepared directly by the reaction of 1 mole of each of C14 - pEOMa = 5 <000 - OH and Cx - pEO ^^ or ^ -OH, with 1 mole of hexamethylene diisocyanate The hydrophilic segments of the multi-buffs and monophobes can contain ramifications A multi-buff and mono-thick mixture containing a branched hydrophilic segment can be prepared, for example, by the reaction 1 mol of trifunctional polyethylene oxide (as prepared by the ethoxylation of trimethylolpropane) with less than 3 moles of R-NCO Alternatively, a trifunctional isocyanate can be reacted with mixtures of RO- (CH2CH20) mH and ZO - (CH2CH20) nH Other suitable materials for forming the mixtures of the invention are the soluble polymers, prepared by free radical polymerization.These water-soluble polymers are polymers of water-soluble monomers, but may contain some insoluble monomers, provided that the resulting polymer is soluble in water. Water-soluble monomers include (meth) acrylic acid, (meth) acrylamide (and analogs having substituents on the amide nitrogen), vinyl alcohol (from the polymerization of vinyl acetate, followed by hydrolysis), and hydroxyalkyl (meth) acrylate. The hydrophobic segments can be introduced in many ways, which include: 1) employing hydrophobic chain transfer agents, such as dodecyl mercaptan; 2) use free-radically polymerizable hydrophobic monomers, such as decyl methacrylate, non-ionic urethane monomers of US-A-4,514,552 or monomers of US-A-4,384,096; and 3) by the subsequent reaction, which includes, for example, the esterification of the functionality of the polymeric acid with hydrophobic-containing alcohols, such as dodecanol, or a non-ionic surfactant. The performance of such mixtures is demonstrated in Example 10 for molecular weight series of the polyhydroxylethyl acrylate polymers, which utilize equimolar amounts of the n-dodecyl mercaptan (n-DDM) chain transfer agent and the monomer that it contains the hydrophobe, as prepared according to Example 4. The n-DDM supplies terminal C12 hydrophobic segments, while the internal hydrophobic pendants are provided by a monomer which contains C12 functionality. The monophobes are those polymers which contain or a terminal of a hanging hydrophobe, but not both; most will often contain only the terminal hydrophobe. The molar ratio of the multiphobic: monophobic in the mixture can vary from 1: 100 to 100: 1. The preferred molar ratio of the multipole: monophobic depends on several factors, including the type of the associative thickener, the general molecular weight of each component and the Mn of the hydrophobic segments of each component. The selection of the monophobic hydrophobic segments does not depend on, nor is it dictated by, the type of hydrophobic multi-phobic segments employed. When the mixture of the invention is prepared in itself or by the synthesis of the monophobic and multiflow components separately, the hydrophobic segments of the multiphobic and monophobic may be the same or different. In an equivalent manner, the selection of the monophobic hydrophilic segments does not depend on, or is dictated by, the type of the multi-phobic hydrophilic segments employed. The method of the invention is useful in improving the viscosity stability of aqueous compositions containing at least one associative thickener. Suitable associative thickeners include the hydrophobically modified, nonionic urethane and ethylene oxide block copolymers (referred to herein as "HEUR"), the hydrophobically modified alkali-soluble polymers [including the hydrophobically modified alkali-soluble emulsions] (hereinafter referred to as "HASE") and the hydrophobically modified poly (meth) acrylic acid], hydroxyethyl cellulose, hydrophobically modified (referred to herein as "HMHEC"), hydrophobically modified poly (acrylamide), and mixtures thereof. The method of the invention is useful for improving the viscosity stability of an aqueous composition containing at least one associative thickener, particularly in the addition of a dye containing high levels of the surfactant. The method of the invention is not limited by the type of dye that is added to the aqueous system and is useful for any dye containing a surfactant or other additives that may interfere with the non-specific associations of the associative thickeners added to the aqueous system. The multiflow and monophobic can be added as a mixture directly to the aqueous composition, before, during or after the addition of the associative thickener. Alternatively, the monophobic and multiflow can be added directly as a mixture to the associative thickener or dye, before addition to the aqueous composition. The multipef and mono-phobic do not need to be added as a mixture and can be added separately to different components of the aqueous composition. For example, the monophore can be provided in the latex, thickener, colorant or other additive of the formulation (such as with empty latex particles or with a complex macromolecular organic compound, having a hydrophobic cavity, such as cyclodextrin or derivatives of cyclodextrin) and the added multiphobic as a separate component. The monophobe can be provided during the synthesis of any of these components, such as, for example, the polymerization of the latex polymer. Likewise, for example, the multiflow may be provided in the thickener or other additive of the formulation and the aggregate monophobic as a separate component. However, the supply of the multiflow as a separate component with the latex is not preferred, because it can cause an unacceptably high viscosity. If the multiflow and monophobe are supplied separately, in which at least one of the components of the mixture is provided with another component of the aqueous composition, then the components can be mixed when a conventional mixing equipment, such as, for example, dispersants high speed, ball mills, sand mills, pebble mills and paddle mixers. The mixture or its component parts can be provided in the form of a dry powder, a previously mixed aqueous solution or an aqueous paste or a solution in a solvent compatible with water. In this aspect, a solvent can be selected to prepare the mixture of the invention, so it can be mixed directly into the aqueous composition. This mixture may contain inert materials that do not interfere with the hydrophobic association of any component of the mixture.

The mixture may be present in the aqueous composition at a level of at least 0.05% by weight solids, based on the weight of the aqueous composition. Preferably, the mixture may be present in the aqueous composition at a level of 0.1% by weight solids and, more preferably, at a level of 0.5% by weight solids, based on the weight of the aqueous composition. Alternatively, the mixture may be present in the aqueous composition containing the latex polymer at a level of at least 0.01% by weight solids, based on the weight of the latex polymer solids. Preferably, the mixture may be present in the aqueous composition containing the latex polymer, at a level of from about 0.05 to 0.25% by weight solids, based on the weight of the latex polymer solids. The method of the invention is useful for latex-containing aqueous systems, such as paints (including architectural paints and metal coatings, such as automotive finishes), coatings, synthetic plasters, adhesives, sealants, and inks . While the method of the invention is particularly useful for aqueous systems containing latexes, this method of the invention is also useful in improving the viscosity stability of other aqueous systems that do not contain a latex, such as cosmetics, hair dyes, water-based cutting oils, drilling fluids, packaging fluids, cleaners, liquid detergents and fabric softeners, pesticide and agricultural compositions, personal care products (including shampoos, hair conditioners, hand lotions, hand creams, astringents, epilators and antiperspirants) and pharmaceutical formulations (which include topical creams and hormone patches). It has been found that the addition of the mixture to aqueous compositions does not compromise such properties as water resistance. Some embodiments of the present invention will now be described in detail in the following examples.

E j emp l o s Example 1: Preparation of the hydrophilic segment = pEO (average Mn = ~ 5,000) hydrophobic segment = part C16 Three hundred grams of toluene and 150 g (0.03 mol) of poly (ethylene glycol) -monomethyl ether (mean Mn = ~ ,000) were loaded into a flask, then stirred and heated to azeotropically remove residual water by means of a Dean Stark trap. The copper temperature was reduced to 90 ° C and 8.02 g (0.03 mol) of hexadecyl isocyanate was added, followed by 0.2 g of dibutyltin dilaurate catalyst. After stirring at 90 ° C for 1 hour, the reaction was complete.

Example 2 Preparation of the hydrophilic segment = pEO (average Mn = ~ 4,600) hydrophobic segment = part C16 Four hundred grams of toluene and 138 g (0.03 mol) of poly (ethylene glycol) (average Mn = ~ 4,600) were charged to a flask, then stirred and heated to remove wastewater azeotropically by means of a Dean Stark trap. The temperature of the copper was reduced to 90 ° C and 16.04 g (0.06 mol) of hexadecyl isocyanate was added, followed by 0.2 g of dibutyltin dilaurate catalyst. After stirring at 90 ° C for 1 hour, the reaction was complete.

Example 3: In situ preparation of a mixture of 1 mol of multiphobe: 2 mol of mono-phobic, hydrophilic segment = pEO (Average Mn = ~ 10,000) hydrophobic segment = part C14-NCO Three hundred fifty grams of toluene and 200 g (0.02 mol) of poly (ethylene glycol) (average Mn = ~ 10,000) were charged to a flask, then stirred and heated to remove the wastewater azeotropically by means of a Dean Stark trap. The temperature of the copper was reduced to 90 ° C and 4.79 g (0.02 mol) of tetradecyl isocyanate was added, followed by 0.2 g of dibutyltin dilaurate catalyst. After stirring at 90 ° C for 1 hour, the reaction was complete.

Example 4: Preparation of the mixture in itself by means of free radical copolymerization One hundred forty-one grams of the n-propanol was charged to a flask and heated to 85 ° C., followed by the addition of 0.5 g of 2, 2'-azobis- (2-methylbutyronitrile, sold under the tradename VAZO 67 by DuPont de Nemours, Wilmington DE.) While stirring and maintained at a temperature of 85 ° C , a mixture of monomers [116 g (l.Omol) of hydroxyethyl acrylate, 36.7 g (0.029 mol) of C12- (EO) 23-methacrylate, 5.85 g (0.029 mol) of n-dodecyl-mercaptan (n-DDM) ) and 91 g of n-propanol] were added gradually over 2 hours and an initiator solution (1.75 g of VAZO 67 in 25 g of propanol) was added gradually in the same 2 hours, plus 0.5 additional hour. The initiator was complete, the polymer solution was maintained for an additional hour at 85 ° C, followed by cooling to room temperature.The final polymer composition was 76HEA / 24C12- (E0) 23- methacrylate // 3.83 n-DDM Examples 5a-9 were carried out using a high quality semi-gloss paint, of the following formulation, scaling at 100 gallons (378.5 liters) of paint, which has a content of pigment volume of 23.5% and 34.2% by volume of solids. The paint was thickened with the indicated associative thickener at a viscosity of 90 + 2 KU.

The viscosity stabilizing ability in the following examples was determined by measuring the change in the average cut-off viscosity (KU) by adding the Colortrend Phthalo Blue dye (available from Creanova Inc., Piscataway, NJ), a commonly used dye which produces significant changes in viscosity when added to most paint formulations that contain an associative thickener. The blends of the invention provide an improvement in viscosity stability relative to a control paint containing the same thickener system. However, it is preferred for latex paints that the average cut-off viscosity (KU) changes by less than 10 KU and more preferably by less than 5 KU, by adding a maximum of 12 oz / gal) 90 g / 1) of Colorant.

Example 5a: Stabilization of the viscosity in a aqueous composition containing latex and an associative thickener HASE The mixture of the invention was prepared according to the synthesis route described in Example 3, except that 172 g (0.02 mol) of the poly (ethylene glycol) (Mn = 8,600) replaced the poly) ethylene glycol (Mn). = 10,000) Type of associative thickener: BASE (Acrysol® TT-935, from Rohm and Haas Company, Philadelphia, PA) The results of the change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 1, together with a control containing the same HASE thickener, but without the mixture of the invention.

Example 5b: Stabilization of the viscosity in an aqueous composition containing latex and a HEUR associative thickener The mixture of the invention was prepared by combining a monophore, prepared by the method of Example 1, with a multiflow, prepared according to the method of Example 2, except that: 1) the monophore used 300 g (0.03 mol) of poly (ethylene glycol) -monomethyl ether (Mn = 10,000 = and 8.87 g (0.03 mol) of octadecyl isocyanate, instead of poly (ethylene glycol) ) -monomethyl ether (Mn = 5,000) and hexadecyl isocyanate, respectively; 2) the multiflow used 258 g (0.03 mol) of poly (ethylene glycol) (Mn = 8,600) and 17.74 g (0.06 mol) of octadecyl isocyanate in place of poly (ethylene glycol) (Mn = 4,600) and hexadecyl isocyanate, respectively.

Type of associative thickener: HEUR (Acrysol® RM-8W + Acrysol® RM-2020NPR from Rohm and Haas Company, Philadelphia, PA) The results of the change in the average cutting viscosity (initial viscosity = 90 KU) are shown in Figure 2, together with a control containing the same HEUR thickener system, but without the mixture of the invention.

Example 6a: Monophobic required for viscosity stability The mixture of the invention was prepared by combining the prepared mono-phobe by the synthesis route described in Example 1, with the multiflow prepared by the synthesis route of Example 2.

Type of associative thickener: HEUR (Acrysol® RM-8W + Acrysol® RM-2020NPR, from Rohm and Haas Company, Philadelphia, PA) The results of the change in the average cutting viscosity (initial viscosity = 90 KU) are shown in Figure 3, together with a control containing the same HEUR thickener, but without the mixture of the invention.

Example 6b Multiphobic required for stability of viscosity Type of associative thickener: HASE (Design Rheology DR-75 of Rohm and Haas Company, Philadelphia, PA) Note: LP-100 is Lipopeg 100-S, available from Lipo Chemicals Inc., Patterson, NJ 07504) and has an Mn of 4,400 (for 100 EO units) The results of the change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 4, together with a control containing the same HEUR thickener, but without the mixture of the invention.

Example 7: The Mn of the hydrophilic segment of the monophore must be at least half of the Mn of the hydrophilic multi-amphobic segment. Each mixture was prepared by combining a monophobe obtained by the synthesis route of Example 1, with a multiphobe obtained by the synthesis route of Example 2, with the substitutions shown in the following table: Type of associative thickener: HASE (Design Rheology ™ DR-75, from Rohm and Haas Company, Philadelphia, PA) The results of the change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 5, together with a control containing the same HASE thickener, but without the mixture of the invention.

Example 8: Mn of the Multiphobic Hydrophilic Segment The mixture of the invention was prepared by the synthesis route of Example 3 [substituting 0.02 mol of several poly (ethylene glycols)] Type of associative thickener: HASE (Design Rheology ™ DR-75, from Rohm and Haas Company, Philadelphia, PA) The results of the change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 6, together with a control containing the same HASE thickener system, but without the mixture of the invention.

Example 9: The hydrophobic segments must be large enough to provide non-specific hydrophobic associations. The mixtures of the invention were prepared by the synthetic route of Example 3, except for the substitution of 92 g (0.02 mol) of the poly (ethylene glycol). (Average Mn = 4,600) and 0.02 moles of the appropriate hydrophobic isocyanate by poly (ethylene glycol) (mean Mn = 10,000) and tetradecyl isocyanate, respectively.

Type of associative thickener: HASE (Design Rheology ™ DR-75, from Rohm aand Haas Company, Philadelphia, PA) The results of change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 7, together with a control containing the same HASE thickener system, but without the mixture of the invention.

Example 10: Performance of the mixtures of the invention, prepared by free radical polymerization Using the hydrophobic monomer and the hydrophobic chain transfer agent in equimolar amounts, the theoretical statistical distribution of the hydrophobes will be from about 3 parts of the multiflow to 1 part of the monophobe.

Type of associative thickener: HASE (Design Rheology ™ DR-75, from Rohm a and Haas Company, Philadelphia, PA) The results of the change in the average cut viscosity (initial viscosity = 90 KU) are shown in Figure 8, together with a control containing the same HASE thickener system, but without the mixture of the invention.

Claims (19)

1. RE IVI NDI CAC IO N ES 1. A method for improving the viscosity stability of an aqueous composition, this method comprises adding to the composition a mixture including: a.) At least one multiflow, this multiflow contains at least one hydrophilic segment and at least two hydrophobic segments; in which the number average molecular weight (Mn) of the multi-buff hydrophilic segment is greater than 2,000; where the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and b.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in that the hydrophobicity of the hydrophobic mono-phobic segment is sufficient to form non-specific hydrophobic associations.
2. 2. The method of claim 1, wherein the aqueous composition comprises a latex polymer.
3. 3. The method of claims 1 or 2, wherein the composition comprises at least one colorant.
4. 4. The method of claims 1 or 2, wherein the composition comprises at least one associative thickener.
5. 5. The method of claim 4, wherein the composition further comprises at least one colorant.
6. 6. The method of claim 1, wherein the multiflow is a diphobe.
7. 7. The method of claim 1, wherein the mixture is added at a level of at least 0.1% by weight solids, based on the weight of the aqueous composition.
8. 8. The method of claim 4, wherein the associative thickener is a thickener selected from the group consisting of hydrophobically modified, nonionic urethane and ethylene oxide block copolymers, hydrophobically modified, alkali-soluble emulsions, poly (meth) acrylic acids , hydrophobically modified, hydroxyethyl cellulose, hydrophobically modified and hydrophobically modified poly (acrylamide), and mixtures thereof.
9. 9. A method for improving the viscosity stability of an aqueous composition, which contains at least one latex polymer, this method comprises the step of adding to the composition a mixture comprising: a.) At least one multiflow, this multiflow contains at least a hydrophilic segment and at least two hydrophobic segments; in which the number average molecular weight / Mn) of the multi-buff hydrophilic segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and b.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in which the hydrophobicity of the hydrophobic mono-phobic segment is sufficient to form non-specific hydrophobic associations and c.) at least one associative thickener.
10. 10. A method for improving the viscosity stability of an aqueous composition, containing at least one latex polymer, this method comprises the step of adding to the composition a mixture that includes: a.) At least one multiflow, this multiflow contains at least a hydrophilic segment and at least two hydrophobic segments, - in which the number average molecular weight / Mn) of the hydrophilic multi-buff segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and b.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in which the hydrophobicity of the hydrophobic mono-phobic segment is sufficient to form non-specific hydrophobic associations and c. ) at least one macromolecular organic compound that forms complexes, having a hydrophobic cavity.
11. 11. A method for improving the viscosity stability of an aqueous composition, this method comprises the step of adding to the composition at least one multiflow, this multiflow comprises a hydrophilic segment and at least two hydrophobic segments; wherein the aqueous composition comprises: a.) a latex polymer; and b.) at least one monophore, this monophore comprises at least one hydrophilic segment and only one hydrophobic segment; in which the number average molecular weight / Mn) of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in that the hydrophobicity of the hydrophobic monophobic segment is sufficient to form non-specific hydrophobic associations; and in which the Mn of the monophobic hydrophilic segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations.
12. 12. A composition, comprising: at least one multiflow, this multiflow contains at least one hydrophilic segment and at least two hydrophobic segments; in which the number average molecular weight / Mn) of the multi-buff hydrophilic segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and b.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in that the hydrophobicity of the hydrophobic mono-phobic segment is sufficient to form non-specific hydrophobic associations.
13. The composition of claim 12, further comprising an associative thickener.
14. The composition of claim 12, further comprising a complex macromolecular organic compound that has a hydrophobic cavity.
15. 15. The composition of claim 12, wherein the multiflow is a diphobe.
16. 16. A composition, comprising: a. ) Water; b.) a latex polymer; c.) at least one multipurpose, this multiflow contains at least one hydrophilic segment and at least two hydrophobic segments; in which the number-average molecular weight of the hydrophilic multi-buff segment is greater than 2,000; in which the hydrophobicity of the hydrophobic multiphobic segment is sufficient to form non-specific hydrophobic associations; and d.) at least one monophobe, this monophore contains at least one hydrophilic segment and only one hydrophobic segment; in which the Mn of the monophobic hydrophilic segment is at least half of the Mn of the multiphobic hydrophilic segment; and in that the hydrophobicity of the hydrophobic mono-phobic segment is sufficient to form non-specific hydrophobic associations.
17. 17. The composition of claim 16, further comprising at least one associative thickener.
18. 18. The composition of claim 17, further comprising at least one colorant.
19. 19. The composition of claim 16, wherein the mixture is present at a level of at least 0.5% by weight, based on the weight of the latex polymer solids.