MXPA99007403A - Water-based emulsion polymers which resist blocking - Google Patents

Abstract

This invention relates to emulsion polymers which have an excellent combination of blocking resistance, water spotting resistance and ethanol spotting resistance. These polymers are made from a monomer mixture including a monomer with a highly polar group which includes either a carboxylated or sulfonated monomer, or both, a monomer having a hydrolyzable silicone group, and a nonfunctional monomer which can be selected to provide a desired minimum film formation temperature. These emulsions polymers are useful in paint and coatings applications.

Description

"WATER-BASED EMULSION POLYMERS THAT RESIST THE BLOCKING" This invention relates to emulsion polymers and to paints and other coatings containing the emulsion polymers. Water-based coatings and paints are well known and have been sold commercially for many years. These coatings and paints are based on emulsion polymers referred to as latex. In addition to latex, these coatings usually contain additional ingredients such as pigments, opacifiers-coalescents and cross-linking agents among others. Quite often, these waterborne coatings and paints will contain a small amount of an organic solvent. These solvents tend to be volatile and produce vapors when the coating or paint is applied. For environmental and safety reasons, it is desirable to reduce the level of the solvent and other volatile components in waterborne coatings and paints. A problem frequently encountered with waterborne coatings and paints is the "blockage". The "blockage" refers to the tendency of the coating or - - paint to adhere also by having a sticky surface after drying. Water-based coatings and paints need to form highly bonded films when dried at their specific application temperature. To achieve this high degree of coalescence, the emulsion polymer must have either a glass transition temperature less than the temperature of application or used together with coalescing solvents. Both approaches usually lead to poor "blocking" properties of coatings or paints. Polymers with a low glass transition temperature usually cause the coating to exhibit poor "final" blocking properties since the polymer will block even when it has completely dried. Coatings formulated with coalescing solvents dry slowly and therefore exhibit poor "early" blocking characteristics for a prolonged period until drying is complete. When the level of the coalescing solvent is increased, this blocking problem often gets worse because the coating or paint dries more slowly. In both cases, the objects coated with these coatings tend to be blocked when the coating is applied and when the objects are stacked. This blockage frequently causes the coating to fail when the objects are - separate. In addition, the coating or paint must be able to withstand the damage caused by exposure to water and solvents such as those commonly present in household cleaners. Attempts to improve block resistance by mixing hard components and soft components can lead to reduced resistance to water and / or solvents. Therefore, it would be desirable to provide an emulsion polymer that resists both initial and final blockage, water staining and staining of common solvents such as ethanol. It would also be desirable to provide a coating composition or paint that is similarly resistant. In one aspect, this invention is an aqueous emulsion having an aqueous phase and a dispersed polymer phase, wherein the dispersed polymer phase comprises particles of a polymer of the monomer mixture that includes (a) from 5.5 percent to 15 percent. percent based on the weight of all monomers, of a mixture of ethylenically unsaturated functional monomers, wherein the functional monomer mixture includes: - - (1) at least 0.5 percent based on the total weight of all monomers, of at least one monomer having a carboxyl or carboxylate group (2) of at least 0.8 percent to 5 percent based on the total weight of all monomers, of at least one monomer having a sulfonic acid, a sulfonate group or a sulfosuccinate group, or both (1) and (2); (b) from 0.5 percent to 10 percent, based on the weight of all monomers, of one or more monomer (s) polymerizable by ethylenically unsaturated addition containing a silicon atom, which binds at least one hydrolysable group, as long as the bond between the silicon group and the non-ethylenic saturation is not hydrolysable; (c) from 75 percent to 94 percent, based on the weight of all monomers, of a non-functionalized vinyl aromatic monomer, a non-functionalized ester of acrylic or methacrylic acid or a mixture thereof, provided that present less than about 1.5 weight percent of the monomer (b), the monomer mixture further comprises (d) at least about 0.1 percent, based on the weight of all the monomers, of a monomer having at least 2 ethylenically unsaturated addition polymerizable groups. In a second aspect, this invention is an aqueous emulsion having an aqueous phase and a dispersed polymer phase, wherein the dispersed polymer phase comprises particles of a polymer of a monomer mixture that includes (a) 3.5 percent a 15 percent based on the weight of all monomers, of a mixture of ethylenically unsaturated functional monomers, where the functional monomer mixture includes: (1) at least 0.5 percent, based on the total weight of all monomers , of at least one monomer having a carboxyl or carboxylate group (2) of at least 0.8 percent based on the total weight of all monomers, of at least one monomer having a sulfonic acid, a group of sulfonate or sulfosuccinate, or both (1) and (2); (b) from 0.5 percent to 10 percent, based on the weight of all monomers, of one or more ethylenically unsaturated addition polymerizable monomers containing a silicon atom, which is linked to at least one hydrolysable group, as long as the link between the - - Silicon group and the non-ethylenic saturation is not hydrolysable; (c) from about 75 percent to about 96 percent, based on the weight of all monomers, of a non-functionalized vinyl aromatic monomer, a non-functionalized ester of acrylic or methacrylic acid or a mixture thereof, provided When less than 1.5 weight percent of the monomer (b) is present, the monomer mixture further comprises at least 0.1 percent, based on the weight of all the monomers, of a monomer having at least 2 polymerizable groups per addition, ethylenically unsaturated; wherein the monomer mixture is polymerized in two stages, wherein the monomers which together form a polymer having a glass transition temperature of less than 25 ° C are polymerized in a first stage, and a monomer which together forms a polymer having a glass transition temperature of at least 60 ° C, are polymerized in a second stage. In a third aspect, this invention is a coating composition comprising the aqueous emulsion of the first aspect. The emulsion of this invention surprisingly exhibits excellent resistance to both blockade - initial as a final even when drying at temperatures well above the glassy state transition temperature of the dispersed polymer particles. In addition, this blocking resistance is not obtained at the expense of a significant loss of water and solvent resistance; this emulsion provides adequate and excellent resistance to both water and ethanol / water mixtures. The aqueous emulsion of this invention includes a continuous aqueous phase and a dispersed polymer phase. The dispersed polymer phase is in the form of particles of a size such that they can remain stably dispersed in the aqueous phase. A scale of appropriate size for the particles is 40 nanometers to 350 nanometers in diameter ("diameter" here refers to the longest dimension of the particle), preferably 50 to 120 nanometers. The dispersed particles comprise a polymer that is prepared by polymerizing a monomer mixture of at least three different types. In this context, "monomer mixture" or "monomer mixture" only means that the polymer contains repeat units of each member of the mixture, but does not require that all monomers must be mixed together prior to polymerization, or that the monomers all must be polymerized simultaneously. As further discussed below, the monomers can be all polymerized in one time, polymerized in sequence, polymerized into groups or any combination thereof. In the general case, the monomer mixture contains at least 5.5 weight percent, up to 15 weight percent of an ethylenically unsaturated functional monomer. However, the level of the functional monomer can be reduced to as low as 3.5 percent or 3 percent, when the emulsion polymer is prepared in a two-stage polymerization reaction, as will be described below. For the purposes of this invention, a "functional monomer" is one that contains a highly polar group. These functional monomers include those which contain one or more ionic groups such as sulphonate or carboxylate groups, precursors of these ionic groups, such as sulfonic and carboxylic acid groups and other highly polar groups which, even when not ionic, impart high polarity to the monomer. These groups include hydroxy, poly (oxyethylene), nitrile and amide. Specific functional monomers useful in this invention include methacrylic acid, acrylic acid, fumaric acid, maleic acid, itaconic acid, succinic acid, hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylamide, acrylonitrile, methacrylonitrile, acetoxyethyl methacrylate, acetoxyethyl acrylate, - acetoacetoxyethyl methacrylate, sodium styrene sulte, l-acrylamido-2-methylpropane sodium sulte, sodium alkylallyl sulfosuccinate (wherein the alkyl group contains up to about 20 carbon atoms) and glycidyl methacrylate. The sulted monomers are monomers with a sulfosuccinate group containing a long hydrocarbon chain (of 6 carbon atoms or greater, preferably up to 20 carbon atoms) frequently function as a surfactant during the polymerization reaction; in this case, the added surfactant can be minimized or unnecessary. However, when these sulfonated or sulfosuccinated monomers are used, it is preferred to also include another sulfonated monomer that does not contain a long chain hydrocarbon group. Those monomers containing acid groups can be used in the form of their salts, preferably salts with a monovalent cation, more preferably, an alkali metal or ammonium salt. In contrast, those monomers containing acid salt groups can be used in the free acid form. The functional monomer mixture includes one or more monomers containing at least one carboxyl or carboxylate group or one or more monomers containing at least one sulfonic acid, sulfonate or sulfosuccinate group. Preferably, monomers of both types are present. The sulfonate group is preferably in the form of a salt, with the cation being monovalent and preferably an alkali or ammonium metal. When present, the sulfonated monomer (s) constitutes at least 0.8 percent, preferably at least 1.5 percent, most preferably at least 2 percent up to 10 percent, preferably up to 5 percent and most preferably up to 4 percent, based on the combined weight of all monomers. When a monomer containing a carboxylate or carboxyl group is present, it constitutes at least 0.5 percent, preferably at least 1.5 percent, most preferably at least 2.5 percent to 10 percent, preferably up to 5 percent and the total weight of all monomers. The second type of monomer is one or more ethylenically unsaturated monomer (s) containing a silicon atom which would be at least one hydrolysable group. In these monomers, the non-ethylenic saturation is bound to the silicon atom through the bond, which in itself is not hydrolysable. The monomer (s) of this type constitutes at least about 0.5 percent, preferably about 1.6 percent, most preferably at least about 2 percent up to 10 percent, preferably up to 7 percent and higher preference up to 4 percent of the weight of all monomers. The monomers of the second type have at least one, preferably at least two and more preferably three hydrolyzable groups linked to the silicon atom. Suitable from these hydrolysable groups are those which include aceto groups (-C (H) = 0) and halogen groups, and groups of the -OR form, where R is a branched or straight cyclic hydrocarbyl, or a group of hydrocarbyl which is substituted with ether, hydroxyl or other inert substituents. Examples of these hydrolysable groups include aceto groups and those in which the R group corresponds to methyl, ethyl, propyl, 1-methyl or l-methyl-2-methoxyethyl. Exemplary monomers of the second type include methacryloxypropyl trimethoxysilane, vinyl tris (l-methoxypropyl-2-oxy) silane, vinyl triethoxysilane, vinyl trimethoxysilane, propyl trimethoxysilane, or -metacryloxy or vinyl triacetoxysilane. When less than 1.5 percent of the monomer of the second type is used, then the monomer mixture must also contain at least 0.1 percent of a monomer having at least two ethylenically unsaturated addition polymerizable groups. In other cases, this last type of monomer is optional, but it is not - - requires This type of monomer can constitute up to 5 percent of the monomer mixture, preferably up to 1.5 percent. Examples of these monomers include divinylbenzene and ethylene glycol dimethacrylate. Preferably, this monomer contains at least two ethylenically unsaturated groups of reactivity that differ significantly, such as allyl methacrylate or allyl acrylate. When the monomer contains ethylenically unsaturated groups of different reactivity, it is possible to provide a polymer that can be post-crosslinked because the more reactive monomer will polymerize as the polymer is prepared, but the less reactive non-saturated group will remain unreacted and it will be available for reaction for a later period of time, such as during the curing of the polymer. The third type of monomer is one or more of the non-functionalized vinyl aromatic monomer (s), acrylic esters or methacrylic esters. By the term "non-functionalized" is meant that the monomer (1) does not contain groups which cause the monomer to be highly polar (as defined above), (2) no groups other than a polymerizable group which reacts during the course of the polymerization, and (3) no silicon atoms having substituents - - hydrolysable. Those appropriate to these monomers include styrene, alpha-methyl styrene, vinyl toluene, vinyl naphthalene, any of which may be substituted inert manner such as with alkyl or alkoxy groups; acrylic and methacrylic esters in which the ester group is alkyl of 1 to 20 carbon atoms, preferably alkyl of 2 to 8 carbon atoms, such as butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, acrylate of 1 -ethylhexyl, methyl and methacrylate. The monomer or monomers of the third type can be selected to provide desirable properties to the polymer. In particular, the monomers may be selected such that the dispersed polymer particles having a glass transition temperature within a desired scale, or so that the polymer particles form a film at a desired temperature. For example, when the third type of monomer of the "hard monomers" such as styrene, and / or methyl methacrylate, and / or tertiary butyl methacrylate, the transition temperature of vitreous state and the forming temperature is greatly selected. Minimum film (MFFT) of the resulting polymer will tend to be high, such as, for example, greater than 35 ° C, preferably greater than 60 ° C. On the other hand, when the third type of monomer of the "mild monomers" such as n-butyl acrylate, and / or n-hexyl acrylate, and / or n-heptyl acrylate, and / or acrylate of 2-ethylhexyl, then the glass transition temperature and the MFFT tend to be lower, such as less than 35 ° C, preferably less than 15 ° C, more preferably less than or equal to 6 ° C. By selecting the third type of monomer appropriately, the glass transition temperature and MFFT of the polymer particles can be adjusted to a desired value. The MFFT is measured by molding a 150 micrometer film of the emulsion on a heating plate having a temperature gradient. The film is dried and the minimum temperature at which the coherent film is formed is recorded as MFFT. The emulsion of this invention is conveniently prepared by polymerizing the monomer mixture just described in an emulsion polymerization in an aqueous phase. These polymerization methods are well known and are described, for example, in Emulsions: Theory and Practice, by P. Becher Reinhold, New York (1959), High Polymer Latices, by D.C. Blackley, Pamerton Publishing Co. , New York (1966); and Emulsion Polymer - - Technology, by Robert D. Athey, Jr. Marcel Dekker, Inc., New York (1991). In general, the emulsion polymerization process includes mixing the monomers in a continuous aqueous phase with sufficient stirring to disperse the monomers into fine droplets. Unless one or more of the monomers has surfactant characteristics, one or more surfactants are present in order to form micelles as reaction sites and to form a stable emulsion having discrete particles of desirable size. A free radical initiator or redox catalyst is usually employed to provide an acceptable polymerization rate and high conversion of monomers to polymer. The monomers can be added to the aqueous phase at the same time in an intermittent operation or a whole portion can be added continuously or in increments as the polymerization continues. The different monomers may be added during different periods of time through the polymerization or at relative variable rates at different times or at the same relative rates through polymerization. The seed polymer particles can be added at the beginning of the polymerization in order to help control the nucleation of the particles and the size of - - the final polymer particles. The weight of the seed particles preferably is not more than 2.0 percent of that of the monomer mixture; in this case, the composition of the seed particles is ignored when calculating the amounts of the different types of monomer in the monomer mixture. In an illustrative polymerization process, the water, the surfactant and the optional seed particles are initially charged into an appropriate reactor and heated to the desired polymerization temperature. The desired polymerization temperature depends on the specific catalyst and monomers employed, and typically ranges from 30 ° C to 100 ° C, preferably 50 ° C to 100 ° C, more preferably 60 ° C to 100 ° C. The initial charge to the reactor may include all or a portion of the monomer mixture. After the initial charge is heated to the desired temperature, one or more streams are fed to the reactor. One of those streams contains the free radical initiator (or redox catalyst). The monomer mixture can be added in one or more separate streams. The additional surfactant can also be added either as a separate stream or mixed with the catalyst of one or more of the monomers. When the monomers are not added together as a single mixture, they can be added as two or more separate streams, which are - - they can add simultaneously, in sequence, or staggered one with respect to the other. After the addition of all streams, the reactor contents are typically heated for a period to complete the polymerization. Frequently this post-addition heating is carried out at a higher temperature. Alternatively, a two stage polymerization process can be used. This two-stage process has the advantage of requiring a smaller amount of the functional monomer. The two-step process, the monomers that are selected from one or more of these types described above which together form a polymer having a glass transition temperature of 25 ° C or less, are polymerized in a first step. The monomers polymerized in the first stage may or may not contain a functional monomer and may or may not contain the monomer containing a silicon atom having hydrolysable substituents. All that is required is that the first stage monomers are polymerized to form a polymer having the glass transition temperature required. The monomers polymerized in the first stage can be mixed and polymerized or can be fed into the reaction mixture as separate streams. One or more of the monomers polymerized in the first stage can be added as part of the initial charge to the reactor, with the remaining monomers in the first stage added as a stream. Once the first stage monomers are added, they are polymerized to a conversion of at least 70 weight percent, preferably at least 80 weight percent, and then the second stage monomers are added. The second stage monomers are selected from the types described above and are selected so as to form a polymer having a glass transition temperature of at least 60 ° C. The second stage monomers may or may not contain a functional monomer and may or may not contain the monomer containing a silicon atom having hydrolysable substituents; all that is required is that the second stage monomers are polymerized to form a polymer having the glass transition temperature required. Functional monomers and the monomer containing the silicon atom having hydrolysable substituents can be added either in the first stage, the second stage or in both. In this invention, all references to the vitreous state transition temperature are those obtained by differential scanning calorimetry (DSC) in a dried latex sample made by pouring a drop of latex into an aluminum crucible and drying for 12 to 20 minutes. hours at room temperature in a desiccator. The - - Samples are evaluated using a Mettler DSC 30 calorimeter, screened at a rate of 10 ° C per minute through a scale of -40 ° C to 110 ° C. In some cases it may be difficult to measure glass transition temperature temperatures separated from the polymer using DSC. In those cases, the vitreous state transition temperature of the polymer formed in each stage can be determined by polymerizing the monomer or monomer mixture alone in a single stage polymerization process and measuring the glass transition temperature of the polymer resulting in the manner just described. For example, the glass transition temperature of the styrene / 2-ethylhexyl acrylate mixture can be determined by polymerizing that mixture in a single stage polymerization, by measuring the resulting glassy state transition temperature. To the extent that the glass transition temperature is affected by the selection of the reaction conditions such as temperature and the free radical initiator, those conditions must be kept constant when the glass transition temperature is determined in this way . A convenient way to calculate the glass transition temperature of a polymer formed from a specific monomer mixture is through the Fox equation: 1 / TgAN = wA / TgA + wB / TgB = ... + wN / TgN wherein A, B and N represent the individual monomers in the mixture containing the N monomers; wA, B and wN represent the weight fractions of the monomers A, B and N, respectively, glass transition temperature AN represents the glass transition temperature of the polymer formed, and the glass transition temperature A, the glass transition temperature B and the glass transition temperature N, represent the transition temperature of the homopolymers of monomers A, B and N, respectively. See T.G. Fox, Bull. Am. Physics Soc., Vol. 1 (3), page 123 (1956). Using the Fox equation, it is possible to select combinations of monomers to calculate which of the combinations will provide a polymer having the glass transition temperature required. The amount of monomers that is added and polymerized is selected so that the resulting polymer emulsion has a desired solids content, and the copolymer particles have a desired size. Preferably, the resulting emulsion has a content - - of solids from 10 percent to 70 percent by weight, most preferably from 25 percent to 55 percent by weight, and the copolymer particles have an average volume diameter of 40 nanometers to 350 nanometers, preferably from 50 nanometers to 120 nanometers. Any surfactant that stabilizes the monomer mixture as discrete droplets and the subsequent copolymer as discrete particles in the aqueous phase, can of course be used. The surfactant may be of the nonionic, anionic or amphoteric type. Exemplary surfactants include alkali metal alkyl carboxylates, polyoxyethylene alkyl phenols, linear alkyl sulfonates, alkyl aryl sulfonates, alkylated sulfosuccinates, amine oxides of 6 to 20 carbon atoms, N, N-bis (carboxyl alkyl) ) and alkyl amines of 6 to 20 carbon atoms. The surfactant of the brand SIPONATETM A246L (which can be obtained Rhone-Poulenc), sodium dodecylbenzene sulfonate, sodium lauryl sulfate, sodium dodecyldiphenylether disulfone, sodium sulfosuccinate N-octadecyl, dioctyl sodium sulfosuccinate, N, N-bis-carboxyethyl lauramine and sulphonated alkylated phenyl ethers, such as DOWFAX * 2EP and DOWFAX * 2A1 (* Trademarks of The Dow Chemical Company, and both obtainable from The Dow Chemical Company) are all agents - suitable surfactants. The surfactant is advantageously used in an amount of 0.1 to 2 percent, preferably from 0.1 to 0.5 percent, based on the weight of the monomer mixture. Suitable free radical initiators include peroxy compounds such as peroxydisulfates (commonly known as persulfates), perfosphates, tertiary butyl hydroperoxide, eumenohydroperoxide and hydrogen peroxide. Ammonium persulfate, sodium persulfate and potassium persulfates are the preferred initiators. Redox catalysts that are activated in the water phase through a water-soluble reducing agent can also be used. The free radical initiator is advantageously used in an amount of 0.1 percent to 5 percent, preferably 0.1 percent to 2 percent, based on the weight of the monomers. If desired, the amount of the initiator or catalyst in excess of the above-mentioned amounts can be added after the addition of the monomer streams, in order to terminate the polymerization. When the monomer mixture contains a monomer having free acid groups, and in particular, free carboxyl groups, it is preferred to stabilize the resulting polymer emulsion by adjusting the pH to more than 5.0. This can be accomplished by adding a fugitive base, such as ammonia, dimethylamine, diethylamine, aminopropanol, ammonium hydroxide or 2-amino-2-methyl-1-propanol, or through the addition of an alkali, such as hydroxide. sodium, potassium hydroxide or sodium, potassium or ammonium carbonate. This base can be added at the end of the addition of the monomer stream (s), after all the monomer addition is complete or after the polymerization reaction is completed. Other ingredients may also be used during the polymerization process as desired, for example, chain transfer agents, stabilizers or preservatives. After the polymerization, the resulting emulsion can be purified by steam or otherwise treated to remove unreacted impurities and monomers. The emulsion of this invention can be formulated in a variety of paints and coatings. The coatings can be formulated for use in a wide variety of applications and the selection of the emulsion of this invention for use in the coating does not require any special ingredients or special formulation techniques. Accordingly, those ingredients and paint and coating formulations that are well known in the art can be used to formulate the - paints and coatings with the emulsion of this invention. Latex can be formulated in crystalline and pigmented coatings and paints. The pigmented formulation, for example, will generally contain a filler or filler, an opacifying agent, or a pigment such as calcium carbonate, talc, silica, aluminum hydroxide, glass powder, titanium dioxide, zinc phosphate, red oxide, carbon black, Hansa Yellow, Benzidine Yellow, Phthalocyanine Blue or Quinacridone Red. These are generally used in sufficient amounts to provide in the coating a pigment volume concentration of 15 percent to 80 percent. In addition, the formulation may contain inorganic dispersants such as sodium hexametaphosphate or sodium tripolyphosphate, organic dispersants such as polycarboxylic acid polymers (eg, Nopcoperse ™ 44c, from Summopco Co., Ltd. and Orotan ™ 681, from Rohm). &Haas), wetting agents, thickeners such as polyvinyl alcohols, polyurethanes such as Acrylsol RM8, Rohm &Hass, and cellulose derivatives, crosslinking agents such as water soluble polyvalent metal salts, aziridine compounds, resins of epoxide or melamine soluble in water, - - or blocked isocyanates dispersible in water; surfactants, dyes and defoamers. Solvents such as alcohols, glycol ethers, tertiary hydroxy amines, ketoximes, active methylene compounds and lactams can also be added. However, it is an advantage of this invention that the use of coalescing type solvents is not necessary in order to obtain good initial and final blocking properties. The following examples are provided to illustrate the invention, but are not intended to limit its scope. All parts and percentages are by weight, unless indicated.

Examples 1, la, and 2-15 A. Preparation of Latexes The following general procedure was used to make latex Examples 1, la and 2 to 15. The composition of the monomer mixture used in each example is given in Table I. In each case, a latex was obtained with approximately 42.5 percent of solid A stainless steel reaction vessel was charged with 81 parts of deionized water and 0.42 part of alkylarylsulfosuccinate sodium of 10 to 12 carbon atoms, and heated to 80 ° C. Then, they were fed to - reactor 10 percent of the total styrene load (when used), 2-ethylhexyl acrylate and methyl methacrylate (when used) over 20 minutes. After addition of the monomer stream, the content of the reaction vessel was maintained at 80 ° C while 0.12 part of sodium persulfate dissolved in 5.25 parts of water was fed for 30 minutes to form the seed polymer particles. Three streams were then added to the vessel, all starting at the same time. The first stream contained the rest of the styrene, the 2-ethylhexyl acrylate and the methacrylic acid and the methacryl oxypropyltrimethoxysilane, and was added to the reactor through 170 minutes. The second stream consisted of sodium p-styrenesulfonate, the rest of the alkylarylsulfosuccinate sodium (10 to 12 carbon atoms) and 28 parts of water. It was added through 180 minutes. The third stream contained 0.35 part of potassium persulfate and 15.75 parts of water and was added through 190 minutes. After the currents were completed, the reaction temperature was maintained at 80 ° C for an additional 120 minutes to complete the polymerization. The monomer compositions used are given in the following table. All amounts provided are parts by weight. The monomers used to make the particles - Seed in situ are included, since the seeds constitute in excess of 5 percent of the mass of the final polymer. CU7ADR0 I No. of the j. Styrene EHA1 MMA2 MAA3 NaSS4 AASS5 MPTS 36.8 50.0 6.8 1.7 1.7 3.0 YA 37.8 50.0 6.8 1.7 1.7 2.0 37.2 50.0 0 6.8 1.7 1.7 1.7 3 * 35.95 52.5 0 6.8 1.7 1.7 0.75 25.1 50.0 14.15 5.1 1.7 1.7 2.25 25.1 50.0 13.3 6.8 0.85 1.7 2.25 25.1 50.0 14.85 5.1 1.7 1.0 2.25 25.1 50.0 12.9 6.8 0.85 1.35 3.0 25.1 50.0 15.35 5.1 0.85 1.35 2.25 - - . 1 50.0 14.0 6.8 0.85 1.0 2.25 10 25.1 50.0 13.75 5.1 1.7 1.35 3.0 11 25.1 50.0 14.95 5.1 0.85 1.0 3.0 12 25.1 50.0 14.25 5.1 0.85 1.7 3.0 13 25.1 50.0 12.8 6.8 1.7 1.35 2.25 14 10.0 50.0 26.: 1.7 1.7 3.0 15 50.0 36.8 6.8 1.7 1.7 3.0 It also contains 0.6 part by weight of alkyl methacrylate; 1 2-ethylhexyl acrylate; 2 Methyl methacrylate; 3 Methacrylic acid; 4 Sodium styrene sulfonate; Sodium alkylallyl sulfosuccinate (of 10 to 12 carbon atoms); 6? -methacryloxy propyl trimethoxysilane (commercially available from DOW Corning as Z-6030.

- - B. Evaluation of the Latex Multiple films of each of the Latex Examples Nos. 1 to 15 were prepared. The films were molded into a black plastic sheet commercially available from the Leneta Company (Leneta sheet) at a wet thickness of 150 micrometers. . The resulting films were evaluated for hot blocking resistance, water spot resistance and ethanol / water stain resistance as follows. For the hot blocking resistance test, duplicate film samples were dried for one day, and others for one week at room temperature. (approximately 21 ° C) in a room held at constant relative humidity of 50 percent. Two duplicate films were blocked at 50 ° C for two hours under a weight of 4 kilograms per square centimeter and then peeled off. The films were then visually inspected to determine the damage and classified on a scale of 0 (complete destruction) to 5 (no damage). The results of this blocking test are reported in Table II. The disclosed values include a classification of the compound of the samples cured during a day and those cured during a week. For water stain resistance test, a drop of water was applied to a sample of film and - - covered with an hourglass. The time required for the film to whiten visibly was classified on a scale of (-) (whitening in less than one hour), (0) (whitening occurred after more than one hour, but less than four hours), and (+) (no more whitening hardly observable after four hours). The results of this water stain resistance test are as reported in Table II. For the ethanol / water stain resistance test, a filter paper soaked in a 50/50 ethanol / water mixture was placed on the film, covered with a watch glass and inspected for four hours. The results were evaluated on a scale of +/- with (+) indicating no more bleaching hardly observable after four hours, which was decreased within 30 minutes after the filter paper was removed and (-) indicating the bleaching easily visible that required more than 30 minutes to disappear. The results of this test are also reported in Table II.

- - TABLE II Number Classification Classification Classification Formation of Resistance Resistance Film Eg Lock the Stain to Ethanol / Minimum Water, Water Temp. ° C 1 5 + + 4 2 5 + + 5 3 4-5 + + 1 4 5 + + 0 5 + + 6 6 5 + + 0 7 4-5 + + 3 8 4-5 + + 3 9 4-5 + + 0 4 + + 0 11 4-5 0 + 3 12 4-5 0 + 0 13 4-5 + + 0 14 4-5 + + 4 4-5 + + 5 As can be seen from the data in Table II, each of these latexes has excellent initial and final blocking resistance, and good to excellent resistance to water and ethanol stains.

C. Evaluation of Coating Formulations Cl. Crystal Coatings Crystal coating formulations of 1 to 9 and 11 to 15 of each of the latexes Examples 1 to 9 and 11 to 15, respectively, were made by mixing the following components at room temperature: TABLE III Latex (50% solids) 84 parts; in weigh Water 11 partee; in weigh Dehydran 1293a 0.3 part by weight Surfynol 104b 0.3 part by weight Byk 346C 0.3 part by weight Ammonia (25% aqueous solution) 0.5 part by weight Acrysol RM8d (10% active) 0.2 part by weight Syloid DE 50e 2.5 partee; in weigh - a A defoamer that can be obtained commercially from Henkel; b A nonionic material commercially available from Air Products; c A wetting agent commercially available from Byk Chemie; d A polyurethane thickener commercially available from Rhome and Haas as a 30 percent solution; ß A commercially obtainable tarnish agent from W.R.

Grace & Co.

Each of the Crystal Coating Formulations 1 to 9 and 11 to 15 was tested for blocking under four sets of conditions. The results are reported in Table III, which is presented below. Under Condition 1, 150 micrometer films (wet thickness) were applied to the Leneta sheet and dried for two hours at about room temperature. Samples of the films were blocked (Condition IA) for 1 hour at 50 ° C under a weight of 0.5 metric ton / square meter and other samples were blocked (Condition IB) for 24 hours at room temperature and under a weight of 1 ton metric / square meter. The films were then separated and evaluated as described above.

Under condition 2, 150 micrometer films (wet thickness) were applied to the Leneta sheet and dried for 48 hours at about room temperature. Some of the film samples were blocked (Condition 2A) for 24 hours at 50 ° C under a weight of one metric ton / square meter and other samples were blocked (Condition 2B) for 24 hours at room temperature and under a weight of 1 metric ton / square meter. The films were then separated and evaluated, as described above. Under Condition 3, the 100 micron films (wet thickness) were applied to the Leneta sheet and dried for 48 hours at about room temperature. Samples of the films were blocked for 12 hours at 35 ° C under a weight of 2 metric tons / square meter. The films were then separated and evaluated, as described above. Under Condition 4, two coatings of 150 micrometer films (wet thickness) were applied to beech wood and dried for 48 hours at about room temperature. Samples of the films were blocked (Condition 4A) for two hours and 50 ° C under a weight of 2.7 metric tons / square meter and the other samples were blocked (Condition 4B) for 24 hours at room temperature and under a weight of 2.7 metric tons / square meter. The films were then separated and evaluated, as described above. The water / ethanol resistance was evaluated for all coatings by applying a 150 micron (wet thickness) film of the coating on the beech wood samples and drying at room conditions for 30 minutes followed by application of a second film of 150 micrometers and drying under ambient conditions. The stain resistance by the ethanol / water mixture was evaluated in multiple samples that were dried for two hours after the application of the second film and in other samples that were dried for 24 hours after the application of the second film. The samples were evaluated by applying to each of them a filter paper soaked in a 50/50 ethanol / water mixture. The filter paper was removed from the various samples after 15 minutes, 30 minutes and after 2 hours. The films were then examined visually for 24 hours after the filter paper was removed. The films were tested for resistance to water staining in the same way with the exception that the filter paper was removed from several samples after 30 minutes, 1 hour and 2 hours. The results of the ethanol / water spotting and water spotting tests were classified on a scale of 0 to 5, with 5 being the best classification. These results are reported in Table IV, which is presented below. TABLE IV Condition Number Condition Condition Condition Example of Blocking Locking Blocking Lock Coating 1A / 1B 2A / 2B 3 4A / 4B 1 2-3 / 4-5 4 / 4-5 3-4 4 / 4-5 2 5/4 1-2 / 4-5 4-5 3-4 / 3-4 3 5/5 5/5 5 4-5 / 4-5 4 4/4 4 / 4-5 3/4 4/4 3-4 / 3-4 3/5 3 2-3 / 4-5 6 4/4 3-4 / 5 3 4/4 7 4-5 / 5 5/5 4 4/5 8 3-4 / 3 3-4 / 4 3 3/4 9 2-3 / 4-5 4 / 4-5 3-4 4-5 / 4 11 4 / 3-4 4/5 4 4 / 4-5 - - 12 0/0 2 / 3-4 1-2 2-3 / 4 13 3/4 5/5 1 4 / 4-5 14 4-5 / 5 4-5 / 5 4 4/5 4 / 4-5 4-5 / 5 4 4-5 / 4-5 TABLE V Resistance Number Resistance Resistance Example of Water, Water, Ethanol / Ethanol / Water dried drying coating, 2 hours Water, 24 hours 2 hours1 24 hours1 drying drying 4 / 3-4 / 3 4-5 / 4 / 3-4 3/3 / 2-3 3/3/3 3/3/5 5/3/5 3/2/4 4-5 / 3 / 4-5 3/3 / 3-4 4-5 / 3/3 3/2/3 1 / - / 3 3/3/3 4/4/4 4/4 / 3-4 3-4 / 3/3 4/4 / 3-4 4/4/4 4/4/4 3/3 / 2-3 2-3 / 2-3 / 2-3 3-4 / 3-4 / 3 3-4 / 3-4 / 3-4 3 / 2-3 / 2-3 2-3 / 2/2 3-4 / 3-4 / 3 3-4 / 3-4 / 3-4 3 / 2-3 / 2-3 - - 3-4 / 3 / 3-4 4-5 / 4 / 3-4 3-4 / 3-4 / 3-4 4-5 / 4-5 / 4 2 / 2-3 / 3 3/3/2 -3 3/3/3 3-4 / 3/3 11 4-5 / 4/4 3-4 / 3-4 / 3 4/4/4 3-4 / 3/3 12 4 / 3-4 / 3-4 4 / 3-4 / 3-4 2-3 / 2/2 2-3 / 2-3 / 2-3 13 4 / 3-4 / 3-4 4-5 / 4/4 3/3 / 2-3 2-3 / 2-3 / 2-3 14 Not given 4-5 / 4 / 2-3 Not given 3-4 / 3/3 15 Not given 4-5 / 4 / 3-4 Not given 5 / 3-4 / 3 i Values released for 30 minutes / 1 hour / 2 hours of exposure time. 2 Values released for 15 minutes, 30 minutes, 1 hour of exposure time.

C2. Pigmented Coatings Examples 1 and IB were evaluated in a pigmented coating designed for architectural gloss paint applications in the following formulation: Table VI Raw materials Parts by weight Propylene glycol 6.05 Dehydran 1293 0.24 Orotan 681a (35%) 1.66 Triton X 100b 0.10 Acrysol RM 1020c 1.46 Tiona RCL-535d 20.41 Latex (42%) 67.14 Dehydran 1293 0.10 to Orotan 681 is an anionic dispersant commercially available from Rohm & Haas; b Triton X 100 is a nonionic surfactant commercially available from Union Carbide; c Acrysol RM 1020 is a polyurethane thickener commercially available from Rohm & Haas; e Tione RCL-535 is a titanium dioxide commercially available from SCM Chemicals.

- - The pigmented coatings were prepared by mixing the first four ingredients and grinding them together for 20 minutes and then adding the remaining ingredients in the order listed with slow stirring. The pigmented coatings were tested for blocking resistance at room temperature and at elevated temperature, 20 ° resistance to glass and water, ethanol and hand cream according to the following test conditions: Resistance to blocking at 23 ° C: Films with a wet thickness of 150 micrometers were applied to a Leneta sheet. Some samples were dried for 1 day and others were dried for 7 days at a temperature of 23 ° C and a relative humidity of 50 percent. The films dried identically were blocked for 24 hours at 23 ° C and 50% relative humidity under a load of 4 kilograms / 25 square centimeters. The films were then pulled to release and the force required to pull them off was rated on a scale of 0 to 5, with 5 implying that no force was required to separate the samples and it is implying that the films were not They could separate.

- Resistance to blocking at 50 ° C (Resistance to Hot Blocking): Films with a wet thickness of 150 micrometers were applied to a sheet of Leneta. Some samples were dried for 1 day and others were dried for 7 days at a temperature of 23 ° C and 50 percent relative humidity. The dried films were blocked identically for 1, 3 or 5 hours at a relative humidity of 50 ° C / 50 percent under a load of 4 kilograms / 25 square centimeters. The films were then separated and the force required to detach them was classified on a scale of 0 to 5, with 5 implying that no force was required to separate them, and 0 implying that the samples could not be separated by pulling. The amount of surface damage was also evaluated and disclosed as a percentage of the total surface area. ° of Brightness: The paints were applied with a reduction rod (wet film thickness of 150 micrometers) in glass, dried for 1 day at 23 ° C and 50 percent relative humidity and evaluated for 20 percent of brightness using a Byk Brightness Meter.

Resistance to Water / Ethanol / Hand Cream: The glass-pigmented coatings were applied with a reduction rod (film thickness of 150 micrometers wet), dried for 7 days at a temperature of 23 ° C and 50% relative humidity and evaluated for water resistance by applying a drop of water in the film dried for either 5 minutes or 30 minutes. The film was evaluated for softening and blistering 10 minutes after the water was removed and classified on a scale of 0 to 2, with 2 implying that there was no softening of the film, indicating 1 a slight softening of the film. film, indicating 0 serious softening of the film. The coatings were tested for ethanol resistance and hand cream in the same way. TABLE VII Number of Example IB Resistance to blocking at 23 ° C after 1 day of drying 3/0% 3/20% after 7 days of drying 4/0% 4/0% Resistance to Blocking at 50 ° C after 1 day of drying, 1 hour of blocking 3/0% 3/20% after 1 day of drying, 3 hours of blocking 3/20% 3/40% after 7 days of drying, 1 hour of blocking 4/0% 4/0% after 7 days of drying, 5 hours of blocking 4/0% 4/0% ° of Brightness 5is 51% Water resistance after 5 minutes after 30 minutes Resistance to hand cream after 5 minutes after 30 minutes Resistance to ethanol after 5 minutes after 30 minutes Examples 16 to 19 Latex Example 16 was prepared in the same manner as Latex Examples 1 to 15, using the following monomer mixture: TABLE VIII Styrene 26.8 parts by weight 2-ethylhexyl acrylate 40 parts by weight Methyl methacrylate 20 parts by weight Methacrylic acid 6.8 parts by weight Sodium sulfonate 1.7 parts by weight Sodium alkylallyl sulfosuccinate (10 to 12 carbon atoms) 1.7 parts by weight Β-methacryloxy propyl trimethoxysilane 3.0 parts by weight The Latex Example 16 and a MFFT of 15 ° C. The formulation of the Latex Example Number 17 can be adjusted (Example Number 17) by substituting 5 parts by weight of methyl methacrylate for an equal amount of 2-ethylhexyl acrylate. In this way, the MFFT can be increased further to 32 ° C. By substituting another 5 parts by weight of methyl methacrylate, by an equal amount of the 2-ethylhexyl acrylate, the MFFT can be increased to 60 ° C (Example 18) and still replacing another 5 parts by weight in methyl methacrylate with an equal amount of 2-ethylhexyl acrylate, the MFFT can be increased up to 80 ° C (Example 19). Coatings of Latex Mixtures Examples 17 and 18 were prepared with Latex Example 1. The same coating formulation was used, as described with respect to Examples 1 to 15, with the exception of a mixture of 1: 1 (by weight ) of c TABLE IX Latex Ratio Hardness Level Hardness Coalescing Mixing Hardness Condition 1 Condition 2 Condition 3 100/0 15//19/20 14/18/20 1/17 70/30 5.5 16 15/25/29 26/55/73 1/18 40/60 7.4 34 27/51/73 26/55/73 1/18 50/50 7.4 27 25/48/61 21/50/64 Examples 20 to 22 Example 20 was prepared by charging a stainless reaction vessel with 49 parts of deionized water, 0.17 part of sodium alkylaryl sulfoccinate (10 to 12 carbon atoms), 0.92 part of itaconic acid and 0.09 part of sodium hydroxide (10 per cent). cent), followed by heating to 82 ° C. Then, a stream containing 0.12 part of sodium alkylarylsulfosuccinate (10 to 12 carbon atoms) in 2.6 parts of water and a second stream containing 2.3 parts of styrene, 0.15 part of MPTS, 2.1 parts of butyl acrylate and 0.33 part of 2-HEMA, they were added through 20 minutes. A second stream of 0.18 part of potassium persulfate dissolved in 7.5 parts of water was started 15 minutes after the start of the monomers and fed to the reactor through 30 minutes to form seed particles in situ. After this initial settling step, monomer stream containing 44.56 parts of styrene, 38.9 parts of butyl acrylate, 6.17 parts of HEMA, 1.43 parts of sodium alkylaminosulfosuccinate (10 to 12 carbon atoms) was continuously added to the reactor. and 2.85 parts of MPTS and a stream containing 0.18 part of the initiator in 7.5 parts of water, through 200 minutes. To ensure good conversion, an additional 0.2 part of potassium persulfate in 5 parts of water was added over a period of 30 minutes after the addition of the monomer was completed. The reaction temperature was then maintained at 82 ° C for an additional 90 minutes to complete the polymerization. Example 21 was prepared in essentially the same manner with the exception that the styrene level was decreased by 1 weight percent and the level of MPTS was increased by the same amount. Example 22 was prepared in essentially the same manner as Example 20, with the exception that no MPTS was added to the reactor during the initial settling step. Instead, all the MPTS was added to the reactor through 60 minutes as a separate stream after the sedimentation step. Latex Examples 20-22 were evaluated for resistance to hot block, water stain resistance and ethanol and MFFT in the same manner as in Examples 1 to 19 and 11 to 15. All were classified as "+" in both strength and stained with water as ethanol and all had an MFFT of 24 ° C. Example 20 had a score of "4" in the hot blocking resistance test, while Example 21 has a score of "4 to 5" and Example 22 has a score of "5".

Example 23 Example 23 was prepared by charging a stainless reaction vessel with 85 parts of deionized water, 2.24 parts of the polystyrene seed latex followed by heating to 80 ° C. Then, 0.32 part of ammonium persulfate dissolved in 45 parts of deionized water was continuously added to the reactor over 300 minutes. A stream of monomer containing 36.4 parts of 2-ethylhexyl acrylate, 26.0 parts of methyl methacrylate, 1.43 parts of methacrylic acid and 1.17 parts of acrylic acid were added through 156 minutes. Then, a stream of 27.4 parts of methyl methacrylate, 4.7 parts of 2-ethylhexyl acrylate, 1.5 parts of MPTS, 0.77 part of meacrylic acid and 0.63 part of acrylic acid were added to the reactor from 156 to 240 minutes. Example 23 was evaluated in a formulation of a crystalline layer of the following composition TABLE X Latex (42.9% solids) 33.4 parts by weight Water 13.6 parts by weight Dehydran 1293a 0.5 parts by weight Surfonyl 104Ea 0.5 parts by weight Byk 346a 0.5 parts by weight Ammonia (25% aqueous solution) 0.5 parts by weight Acrysol RM8a (10% active) 1.7 parts by weight Syloid DE 50a 2.5 parts by weight Aquacer 531f 2.0 parts by weight Butyl glycol: methoxybutanol 2: 1 5.0 parts by weight a See notes to e of Table III f A wax additive commercially available from Byk Chemie - - The coating was evaluated for blocking by condition 1A / 1B as described above in section Cl of Example 1. Samples for evaluating water and ethanol / water resistance were prepared by applying a 150 micron wet film. in wood and drying for 2 days at room temperature. The samples were evaluated by applying a filter paper soaked in a 50/50 ethanol / water mixture to each of them. The filter paper was removed from several samples after 30 minutes, 1 hour and 5 hours. The films were then visually inspected. The sample exposed to the filter paper for 5 hours was inspected 24 hours after the filter paper was removed. The films were tested for stain resistance in the same manner, except that all films were inspected immediately after the filter paper was removed. The results of the ethanol / water spotting and water spotting tests were classified on a scale of 0 to 5, with 5 being the best.

Example No. of Resistance Condition Ethanol / Water Coating Blocking 1A / 1B to Water 23 3-4 / 5 4-5 / 3/4 4-5 / 4-5 / 4-5 - - Examples 24 to 28 These latexes of Examples 24-28 were prepared according to the procedure given for Example 1. The composition is given in Table XI TABLE XI No. of Ej. Styrene EHA6 MAA7 COMONOME AASSe MPTS " 24 35.5 50.0 6.8 3.0 HEA1 1.7 3.0 35.5 50.0 3.0 GMA2 1.7 2.0 26 36.8 50.0 6.8 1.7 AAEM-3 1.7 1.7 27 36.8 50.0 6.8 1.7 SEM4 1.7 0.75 28 36.8 50.0 6.8 1.7 AMPS5 1.7 2.25 1 2-hydroxyethyl acrylate; 2 glycidyl methacrylate; 3-acetoxy acetoxyethyl methacrylate; 4 sulfoethyl methacrylate - sodium salt; Sodium salt of sulfonic acid of 2-acrylamido-2-methylpropane; 6 See notes 2, 3, 5 and 6 of Table I.

- - The resulting latexes were evaluated essentially in the same formulation as Example 23 except that only 2 parts by weight of the ethylglycol: methoxybutanol mixture was used. The latexes were evaluated for blocking, resistance to the guide and resistance to ethanol using the same methods used to evaluate Example 23. The results are disclosed in Table XII.

TABLE XII Stained Spotted Blocking Number Example with Ethanol Water 24 2 / 4-5 4/4 / 3-4 3/3/2 1/4 4-5 / 4/3 3/3/3 26 2-3 / 5 3/5 / 3-4 4/4/4 27 3-4 / 5 3/3/3 3-4 / 3-4 / 3 28 3-4 / 5 4-5 / 4-5 / 4-5 3/3/3

Claims (24)

- - CLAIMS:

1. An aqueous emulsion having an aqueous phase and a dispersed polymer phase, wherein the dispersed polymer phase comprises particles of a polymer of a monomer mixture that includes (a) from 5.5 percent to 15 percent based on the weight of all monomers, from a mixture of hydrophilic ethylenically unsaturated monomers, wherein the hydrophilic monomer mixture includes: (1) at least 0.5 percent based on the total weight of all monomers, of at least one monomer having a carboxyl or carboxylate group, and / or (2) at least 0.8 percent based on the total weight of all monomers, of at least one monomer having a sulfonic acid, sulfonate or sulfosuccinate group; (b) from 0.5 percent to 10 percent, based on the weight of all monomers, of one or more ethylenically unsaturated addition polymerizable monomers containing a silicon atom, to which at least one hydrolysable group is attached, as long as the bond between the silicon group and the non-ethylenic saturation is not hydrolysable; (c) from 75 percent to 94 percent, based on the weight of all monomers, of a non-functionalized vinyl aromatic monomer, a non-functionalized ester of acrylic or methacrylic acid, or a mixture thereof, as long as less than 1.5 weight percent of the monomer (b) is present, the monomer mixture further comprises at least 0.1 percent, based on the weight of all the monomers, of a monomer having at least 2 polymerizable groups by addition ethylenically unsaturated.

2. The aqueous emulsion of claim 1, wherein the monomer mixture contains the component (a) (1).

The aqueous emulsion of claim 2, wherein the component of the monomer mixture (a) includes an ethylenically unsaturated addition polymerizable monomer having at least one carboxyl or carboxylate group and at least one other monomer that does not it contains an ionic group or a precursor of an ionic group.

The aqueous emulsion of claim 3, wherein component (a) of the monomer mixture includes methacrylic acid, acrylic acid, fumaric acid, maleic acid, itaconic acid or succinic acid and 2-hydroxyethyl acrylate or methacrylate of 2-hydroxyethyl. - -

5. The aqueous emulsion of claim 2, wherein the monomer mixture further contains component (a) (2).

The aqueous emulsion of claim 5, wherein the component of the monomer mixture (a) (2) includes a sulfonated monomer with a hydrocarbon chain of 6 or more carbon atoms.

The aqueous emulsion of claim 6, wherein the component of the monomer mixture (a) (2) further includes a sulfonated monomer without a hydrocarbon chain of 6 or more carbon atoms.

8. The aqueous emulsion of claim 5, wherein the monomer mixture component (a) (2) includes a sulfonated monomer without a hydrocarbon chain of 6 or more carbon atoms.

9. The aqueous emulsion of claim 1, wherein the component of the monomer mixture (a) (2) is present.

The aqueous emulsion of claim 9, wherein the component of the monomer mixture (a) (2) includes a sulfonated monomer with a hydrocarbon chain of 6 or more carbon atoms.

11. The aqueous emulsion of claim 10, wherein the component of the monomer mixture (a) (2) - - it further includes a sulfonated monomer without a hydrocarbon chain of 6 or more carbon atoms.

The aqueous emulsion of claim 9, wherein the component of the monomer mixture (a) (2) includes a sulfonated monomer without a hydrocarbon chain of 6 or more carbon atoms.

13. The aqueous emulsion of claim 1, wherein the silicon atom is linked to two or three hydrolyzable groups.

The aqueous emulsion of claim 3, wherein the silicon atom is linked to two or three hydrolyzable groups.

15. The aqueous emulsion of claim 9, wherein the silicon atom is linked to two or three hydrolysable groups.

16. The aqueous emulsion of claim 1, wherein the component (c) of the monomer mixture is selected such that the polymer has an MFFT of less than or equal to 6 ° C.

17. The aqueous emulsion of claim 1, wherein the component (c) of the monomer mixture is selected such that the polymer has an MFFT of more than 35 ° C.

18. The aqueous emulsion of claim 3, wherein the component of the monomer mixture (a) (2) is - - a mixture of sodium styrene sulfonate and sodium alkylallyl sulfosuccinate of 10 to 12 carbon atoms.

The aqueous emulsion of claim 5, wherein the component of the monomer mixture (a) (2) is a mixture of sodium styrene sulfonate and sodium alkylallyl sulfosuccinate of 10 to 12 carbon atoms.

20. The aqueous emulsion of claim 18, wherein the silicon atom is linked to 2 or 3 hydrolyzable groups.

21. An aqueous emulsion having an aqueous phase and a dispersed polymer phase, wherein the dispersed polymer phase comprises particles of a polymer of the monomer mixture including (a) from 3 percent to 15 percent based on the weight of all monomers, of a mixture of ethylenically unsaturated functional monomers, wherein the functional monomer mixture includes: (1) at least 0.5 percent based on the total weight of all monomers, of at least one monomer having a carboxyl or carboxylate group (2) of at least 0.8 percent based on the total weight of all monomers, of at least one - monomer having a sulfonic acid, a sulfonate or sulfosuccinate group, or both (1) and (2); (b) from 0.5 percent to 10 percent, based on the weight of all monomers, of one or more of the ethylenically unsaturated addition polymerizable monomers containing a silicon atom, to which at least one group is linked hydrolysable, as long as the bond between the silicon group and the non-ethylenic saturation is not hydrolysable; (c) from 75 percent to 96 percent, based on the weight of all monomers, of a non-functionalized vinyl aromatic monomer, a non-functionalized ester of acrylic or methacrylic acid, or a mixture thereof, as long as less than 1.5 weight percent of monomer (b) is present, and the monomer mixture further comprises at least 0.1 percent, based on the weight of all monomers, of a monomer having at least 2 polymerizable groups per ethylenically unsaturated addition, wherein the monomer mixture is polymerized in two stages, wherein the monomers which together form a polymer having a glass transition temperature of minus 25 ° C, are polymerized in a first stage and a monomer which together with this forms a polymer having a glass transition temperature of at least 60 ° C are polymerized in a second stage.

22. A coating composition comprising an aqueous emulsion of claim 1.

23. A coating composition comprising the aqueous emulsion of claim 21.

24. A coating composition containing the aqueous emulsion of any one of claims 1 to twenty-one.