DE1795018A1 - Process for the preparation of polymer emulsions - Google Patents

Description

The invention relates to a process for the production of aqueous polymer emulsions with a solids content in the range from about 50 to 75 % _9, in particular valuable, stable, aqueous homo- and mixed polymer emulsions which have a useful viscosity and at the same time a higher solids content than was previously achieved using conventional techniques the emulsion polymerization is achievable.

Aqueous emulsions containing various homopolymers and copolymers, e.g. B. homo- and mixed polymers of vinyl acetate and of lower alkyl acrylates and methaorylates, such as ethyl acrylate and methyl methacrylate, and the like, have been known for many years. In the processes used to produce such polymer emulsions, one or more ethylene-unsaturated substances are generally added with rapid stirring

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Monomers to water that contains oberflächenaktiv® gowns or emulsifiers »a polymerisation catalyst or pathogen and, in many cases, a protective ecolloid former or is mixed with these at the same time or afterwards. This mixture is then heated to the polymerization temperature with continued stirring and kept at this temperature until the monomer or monomers Cn) is or are essentially completely polymerized and the polymer emulsion is present. After cooling and filtering, the resulting emulsion can be used in many household and technical applications, depending on the polyaers present and the properties of the emulsions containing them, such as in paints and other coating materials, e.g. B. Paper coating and text treatment agents ^ in adhesives or binders, in sealants and the like.

Acrylic polymer emulsions, in particular those with a content of polymers which are prepared using a predominant amount of a lower alkyl acrylate susansmen with smaller amounts of other comonomers, %. B. styrene, alkyl methacrylates, Höherwol .-. Ilkyl-aerylaten, acrylic or methacrylic acid, vinyl and ¥ inylidenhalogeniden and the like, have been used in the last few years to an ever increasing extent in the so-called paints on Massergntmdlage. Filises obtained with such polymers are normally, especially in pigmented form, an excellent appearance and permanent durability,

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and paints or other coating agents containing them generally result in the most satisfactory final adhesion to a variety of documents.

However, a problem that has generally arisen up to now with polymer emulsions is that they cannot be produced Emulsions with a solids content greater than about 50 Ji, the neither too viseos for convenient handling nor so little shelf life are that their use in paints or other commercial coating materials is impossible, hardly, if at all possible.

Polymer emulsions with a high solids content are very interesting for paint manufacturers. Such emulsions would firstly, due to their lower water content, they lead to savings in shipping and storage costs, and furthermore also cause lower production costs, both in the production of the emulsion as such, since with increasing Solids content the emulsion productivity increases considerably, as well as when using the emulsion, since z. B. coatings or films of any desired thickness could be applied in fewer passes.

The paint manufacturer also generally prefers it before, as large as possible of the total water content of the paint preparation for the production of to have available pigment dispersions to be mixed with the polymer emulsion. High solids polymer emulsions

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Naturg @ mäas claim a smaller share of the total available water than the corresponding conventional ones Emulsions,

The present invention makes polymer emulsions of high quality Solid content available. These emulsions are surprising available through a process with the following stages:.

1. By adding or using at least one polymerizable monomer which contains at least one ethylene-unsaturated group, in the presence of sufficient amounts of at least one surface-active agent, to obtain a stable pre-emulsion and subsequently. If a stable latex polymer is obtained, an aqueous pre-emulsion is formed. The amount of water in the pre-emulsion is in the range from about 6 to 25 wt. Jl ₁ based on the total monomer (R) in the pre-emulsion. The monomer (s) must not only be capable of polymerizing, but also of forming a permanent emulsion in the water present.

2. The monomer pre-emulsion is then added in portions or continuously Lich to a reaction medium which is part of the not required to form the pre-emulsion, but to achieve the desired solids content in the finished product contains necessary water and a sufficient proportion of a free radical polymerization catalyst, among other things

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to cause the polymerization of at least one of the polymerizable monomers in the pre-emulsion. The reaction medium is kept at temperatures appropriate to the excitation and continuation of the polymerization reaction. The speed at which the pre-emulsion is added is controlled in such a way that an essentially complete conversion of the monomer (as close as possible to 100% ) into the latex polymer with its addition is obtained. The polymerization of the monomer or monomers takes place in the presence of a free radical polymerization catalyst, which is present in a sufficient amount or is added to a substantially complete (as close as possible to 100 % ) conversion of the monomer to form a latex with a total solids content in the range of about 50 to 75 Jf, preferably in the range of 60 to about 75 % or more. This Latexp ^{o: I} -y ^mer content material ^of high solids a processable Viacosität must have and have a higher solids content than is achievable by any known technique.

The present invention thus provides a new process for preparing aqueous polymer emulsions, in particular aqueous acrylic polymer emulsions. It enables the production of aqueous acrylic polymer emulsions which have both useful viscosity values and a higher solids content than was previously achievable by known methods . Further advantages and details of the purpose of the invention can be found in the following description.

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The high solids content emulsions obtained by the process according to the invention contain homopolymers or copolymers based on polymerizable, ethylene-unsaturated monomers, in particular monomers which have a single HgCsCC ^ group included.

The homopolyrasren obtainable by this process include the polymers of the unsaturated monomers which form a stable emulsion in water and which form the polymer φ tion nit are self-capable. Typical such monomers are styrene, alky! methacrylates, alky! acrylates, acrylic or Methacrylic acid, vinyl and vinylidene halides, vinyl esters,, such as allyl esters of saturated monocarboxylic acids, vinyl ethers, Dialkyl esters of mono-ethylene-unsaturated dicarboxylic acids, polymerizable © Ethylene-unsaturated mono- and polycarboxylic acids as well as available anhydrides, nitriles, unsubstituted amides and substituted (including N-substituted) Amides of these acids and the like. A more detailed description of those that can be used for homopolymerization, special compounds can be found in the list of compounds mentioned for use as copolymers. The person skilled in the art can easily determine which compounds of the classes described above are to be homopolyraerized and which are to be used for the formation of copolymers. Of particular importance, however, are the monomers described above, which have excellent properties in the end use when used in copolymers as described later result.

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At least one main monomer component of this polymer is usually formed from an alkyl aylate or methaerylate, in particular the former. Usually employed a Alkyi & is erylat © the methacrylate with less than 10 carbon atoms in the alkylene group!, 2-Äthylhexylmsthacryl-at as methyl acrylate, Ithylaerylat, propyl acrylate, n ~ Butylaerylat, isobutyl acrylate, 2-ethylhexyl acrylate, Methylmethaerylat ₅ Xthylmethacrylat, Isohufcylmethacrylat and.

Can disregard the miseh polymerisation with one another the above-mentioned monomeric acrylates and methacrylates as well copolymerized with one or more other monomers become, and indeed interpolymers are used for many technical purposes with monomers containing functional groups »in particular those which are the points for the subsequent crosslinking result, preferred.

Eu these other comonomers include higher mol. Alky! Esters acrylic and methacrylic acid, d. H. those with 10 to or more carbon atoms in the ester part, such as decyl acrylate and decyl, hendecanyl, lauryl, tridecanyl, myristyl, Pentadecanyl, arachidyl, behenyl, 10-methyl-hendecanyl and 2-ethyllauryl methacrylate and myristyl aerylate.

Derivatives of hypothetical vinyl alcohols, e.g. B. aliphatic vinyl esters, such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate, vinyl caproate and the vinyl ester of Versatlc Acid, in amounts up to about 90 t or more, based on the total weight of the

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used monomers, are used, and also are Allyl esters of saturated monocarboxylic acids (including those with unsaturated components that are related to the polymerization are non-reactive), e.g. B. allyl acetate, allyl propionate and allyl lactate, can be used, the latter esters generally being relatively small Quantities together with larger quantities of one or more, other vinyl monomers, in particular aliphatic vinyl esters such as vinyl acetate, are used «

Aliphatic vinyl ethers such as methyl vinyl ether, ethyl vinyl ether and n-butyl vinyl ether are also useful, and vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone and isobutyl vinyl ketone, and dialkyl esters of simple Ethylene-unsaturated dicarboxylic acids are used, for. B. diethyl maleate, dibutyl maleate, dioctylraaleate, diisooctyl maleate, Dinonyl maleate, diisodecyl maleate, ditridecyl maleate, dipropyl fumarate, dibutyl fumarate, dioctyl fumarate, diisooctyl fumarate, Didecyifumarate, dibutyl itaconate and diootyl itaconate.

Polymerizable, ethylene-unsaturated comonomers are also used Mono- and polycarboxylic acids as well as the available anhydrides, nitriles, unsubstituted amides and substituted asides (including N-substituted amides) of the acids can be used.

Specifically, one can use monocarboxylic acids such as acrylic, methacrylic, xthacrylic and crotonic acids, monocarboxylic acids such as maleic, fumaric,

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Itaconic and citraconic acid and simply ethylene-unsaturated tricarboxylic acids such as aconitic acid as well as their halogen-substituted (e.g. fluorine, chlorine and bromine-substituted) derivatives, e.g. <*> -chloroacrylic acid, and, if available, the anhydrides of these acids, z. B. maleic anhydrides, fumaric anhydride and citraconic anhydride work.

To the nitriles of such acids for the purposes of the invention include acrylonitrile, ^ -Chloracrylonitril and methacrylonitrile and BU the amides unsubstituted amides, such as acrylamide, methacrylamide and otheroc-substituted acrylamides, and N-substituted asides, which by reacting the amides of the above mono- and polycarboxylic acids in a known manner with a Aldehyde, such as formaldehyde or the like, can be obtained, see, for example, N-methylol methacrylamide, N-methylolraethacrylamide, alkylated N-Methylolacryland.de and N-methylol methacrylamides, such as N-methoxymethyl acrylamide and N-methoxymethyl methacrylamide, and the same.

The amino monomers for the purposes of the invention include substituted and unsubstituted amino alkyl acrylates, hydrochlorides of the unsubstituted amino monomers and methacrylates, such as Aminoethyl acrylate, ß-aminoethyl acrylate, aminomethyl methacrylate, B-Aminoäthylraethacrylat, Dimethylairinomethy lacrylat, ß-Dimethylaminoäthylacrylat, Diraethylaminoäthylmethacrylat, ß-Diraethylaminomethylmethacrylat and the like, and to the hydroxy-containing monomers ß-Hydroxyäthylacrylat, B-Hydroxypropyl Acrylat, B-hydroxyethyl methacrylate and the like.

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Typical ^H "compounds", that is, those which provide sites for subsequent crosslinking, such as the above-mentioned _s, are generally used in amounts in the range from about 0.1 to 6% by weight, based on the total weight of the monomers used, used.

Furthermore, although aqueous mixed polymer emulsions in which the mixed polymer contains one or more alkyl arylates or methacrylates with less than 10 carbon atoms in the alkyl part as the predominant monomer component (ie at least more than 50 %, based on the total weight of the monomers used), the preferred after _s but this Alkylacryla.te or methacrylates may be generally in amounts of from about 5 to 100 JS, based on the total weight of the monomers used, the method according to the invention produced Misshpolymergattung.

The method according to the invention is therefore not limited to Production of copolymers in aqueous emulsion, the predominant amounts of alkyl alkylates or acrylic acrylates contain, or limited the production of copolymers in which only the monomers described above with copolymerized with these alkyl acrylates or methacrylates are. Apart from the possibility of Horaopolymer production these alkyl acrylates and methacrylates can also be used, as above mentioned, are not present in predominant amounts and can also be used monomers not specifically mentioned above.

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So you can ζ. B. copolymerize styrene and substituted styrenes with these alkyl acrylates and methacrylates and prepare interpolymers which one or more of these alkyl acrylates and methacrylates together with one or more other comonomers, a. B. vinyl acetate, the amount of the latter monomer or monomers above about 50% by weight based on the above basis.

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Any anionic or nonionic surfactant (including the can be referred to as emulsifier, dispersant or wetting agent) or mixtures thereof, which in the production of conventional acrylic polymer emulsions let use.

Nonionic surfactants for the purposes of the invention include polyethers, e.g. B. Ethylene oxide and propylene oxide condensates in general, including straight and branched chain alkyl and alkylaryl polyethylene glycol and polypropylene · glycol ethers and thioethers, and especially substances in the type of "Igepale ⁿ , members of a homologous series of alkylphenoxypoly (fithylenoxy) ethanols, the through the general formula

- (CH ₂ CH ₂ °> nl CH ₂ CH ₂ OH

can be represented in which R is an alkyl radical and η is the number of moles des xthylene oxide means, including alkylphenoxypoly (ethyleneoxy) ethanol «with alkyl groups with about 7 to 18 carbon atoms and having from about 4 to 210 ethyleneoxy units, such as Heptylphenoxypoly- (ethyleneoxy) -ethanols, Nonjrlphenoxypoly- (ethyleneoxy) -flthanols and dodecylphenoxypoly- (ethyleneoxy) -ethanols, the "Tweens", polyoxyalkylene derivatives of Hexitol- ^ nhydride-partial-long-chain-fatty acid-esters (where for hexitol Sorbitans, Sprbide, Mannitans, and Mannides include) like that Polyoxyalkylene derivatives of sorbitanoonolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan

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monooleate and sorbitan trioleate, the "Pluronics", condensates of ethylene oxide with a hydrophobic base formed by condensation formed by propylene oxide with propylene glycol, sulfur-containing condensates, ε.B. caused by condensation of Xthylene oxide with Hohennol.-alkyl-raercaptaneii, such as nonyl, dodecyl or tetradecy! mercaptan, or with alkylthiophenols with 6 to 15 carbon atoms in the alkyl group obtained, xthylene oxide derivatives of long-chain carboxylic acids, such as lauric, Myristic, palraitic or oleic acid or acidic preparations, such as Tall oil and ethylene oxide derivatives of long-chain alcohols, such as octyl, decyl, lauryl or cetyl alcohol.

The anionic, surface-active agents for the purposes of the invention include the higher molecular weight sulfates and sulfonates, z. B. Sodium and potassium alkyl, aryl and »alkylaryl sulfates and sulfonates, such as sodium-2-ethylhexyl sulfate, potassium-2-ethylhexyl sulfate, Sodium nonyl sulfate, sodium undecy! Sulfate, Sodium tridecyl sulfate, sodium penfcadecyl sulfate, sodium lauryl sulfate, Sodium methylfoenzenesulfonate potassium methylbenzenesulfonate, Sodium dodecylbenzenesulfoaate, Kaliuiaifcoluolsulfotiat and Natrium ™ xylene sulfonate, higher fatty alcohols, ss. B. stsaryl, lauryl alcohol etc., which have been ethoxylated and sulfonated, dialkyl esters of alkali metal sulfosuccinates, such as sodium diamyl sulfosuccinate, Sodium dihxylsulphosuccinate and sodium dioctylsulphosuccinate, and pos? Maloehyde naphthalenesulphonic acid condensation products.

The production of the in the method according to the invention

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used pre-emulsion, the monomersCs), surface-active (s) Contains agent and water is preferably done by first mixing the surface-active agent or the mixture of surface-active agents with water and then the monomer or stir in the monomer mixture. The monomer addition to the mixture of surfactant and water should take place at such a rate that the monomer pre-emulsion continuously forms, while at the same time an accumulation of non-emulsified monomer on the surface of the mixture of the surfactant and water is avoided. This speed varies from system to system, but generally the monomer is added more slowly at the beginning and then more rapidly as the manufacturing process progresses.

The term "permanent pre-emulsion" is used herein used meaning a monomer emulsion, which its emulsion properties at least during the addition of the pre-emulsion to the reaction medium and preferably for a long time such as 6 months and longer.

The Monomergesamtgehalt the Monomor pre-emulsion, in the production of the polymer emulsions of high Peststoffgehalt according dei "invention about 75 to 94 wt.%, Based on the total weight of the monomer pre-emulsion, amount, with a range of about 75 to 90 wt.%, Preferably will.

The amount of surfactant used in forming the monomer pre-emulsion is generally the same the amount conventionally used in emulsifying monomers in an emulsion polymerization and ranges e.g. B.

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from about 1 to 10 % , based on the total weight of the monomer pre-emulsion, regardless of whether a nonionic or anionic surface-active agent or a mixture of the two surface-active agents is used. Typical nonionic surfactants, e.g. B. in the form of the above-described alkylph8noxypoly (ethyleneoxy) ethanols with about k to 2 ¹ K) xthyleneoxy units, or typical anionic, surface-active agents, e.g. B. an ethoxylated, higher fatty alcohol that has also been sulfonated, but are preferably used in amounts in the range of about 1.5 to δ Qew. % » Based on the above fasis, used«.

One way of determining the amount of water desired to make the monomer pre-emulsion is by Measurement of the specific conductivity of the pre-emulsion Production with a greater or lesser amount of water are identical in every respect, the values obtained specific conductivity graphically against the water content of the pre-emulsion, a curve is obtained which at least approximately and preferably clearly has a break or inflection point shows.

It has been shown that monomer pre-emulsions produced with such amounts of water in the subsequent polymerization Provide polymer emulsions with a high solids content with the lowest possible viscosity that can be achieved with an emulsion with the

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amounts of polymers present! and surfactant is possible. In other words, there is a direct, and in most cases almost absolute, correspondence between the Above-mentioned break point or inflection point of a curve of the specific conductivity as a function of the amount of water present in the monomer pre-emulsion and the point of minimum Viscosity of a curve of the amount of water present in the monomer pre-emulsion as a function of the viscosity of the Polymer emulsion prepared from monomer pre-emulsion.

It has also been shown in all cases that the respective «amount of water in the preparation of the monomer pre-emulsions generally about 1 mole per mole for the purposes of the invention of the present monomer, more specifically about 0.9 to 1.9 moles per mole of the monomer used, this amounts to about 6 to about 25 wt.% of water, based on that in the pre-emulsion total monomers present. The water range is preferably about 10 to 25% by weight, based on that in the Total monomers present in pre-emulsion. Monoraer pre-broadcasts, those with these amounts of water instead of with the exact amounts which give the above-mentioned break or inflection point of the curve of the specific conductivity of the monomer pre-emulsions, d. H. produced without prior measurements of the specific conductivity, however, are generally sufficiently close in the ideal case, to give a satisfactorily high solids content in conjunction with useful viscosities of the finished polymer emulsion. .

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The specific conductivity, which can also be defined as the reciprocal value of the resistance, is to be understood here as the amount of electricity that is transferred per unit of potential gradient via the volume unit of monomer / pre-emulsion (cf. 61asstone ₉ "An Introduction to Electrochemistry", D. Van Nostrand Company, New York, 19 * 12, Chap. II, in particular pp. 29 and 30). A convenient method used here for measuring the specific conductivity consists in the use of a conductivity bridge of the Leeds & Northrup type, "Conductivity Bridge", model * 1866, using a glass immersion cell with a cell constant of 0.8 * 1 _s where the W & hl the cell constant is largely based on the specific conductivity that determines the au. For example, a cell constant of around 1.0 is recommended for specific conductivities in the range from 5 to & 1Q00 microsiemens / em. In order to achieve reproducibility of the conductivity values, the use of well deionized water is necessary in the production of the monomer yoremulsienes, the specific conductivity of which is to be measured, but this is no longer essential once the amount of water has been determined for a given monomer pre-emulsion. The conductivity determination should also be carried out on freshly prepared monomer pre-emulsions, since tests have shown that the same conductivity values are no longer obtained after the monomer pre-emulsion has stood for 24 hours and that even the expected kink or turning points of the curves of the specific conductivity as a function of the water content of the monomer pre-emulsion no longer occur if the monomer pre-emulsion is allowed to age overnight. One

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Deaeration of the Monoraer pre-emulsion is to achieve a adequately precise determination of the specific conductivity, however, not necessary. Practice has shown that cutting off about half of the platinum electrodes is conductive The glass screens surrounding the gap make the electrodes more accessible to the relatively thick monomer pre-emulsions makes and facilitates faster and more precise determinations of the specific conductivity.

Apart from the surface-active agent or the mixture of surface-active agents, the monomer pre-emulsion or starting charge can also contain small amounts of one or more protective colloids, which is particularly true for carrying out a polymerization of the reflux type using vinyl acetate or the like as part of the monomer charge. Such substances include protective colloids containing ether bonds, such as hydroxymethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl cellulose, ethoxylated starch derivatives W and the like. But you can also work with other protective colloid formers, ie substances containing no ether bonds, alone or together with the aforementioned substances containing ether bonds, including partially and completely hydrolyzed polyvinyl alcohols, polyacrylic acid, polyacrylates of sodium and other alkali metals, polyacrylamide, poly-methyl vinyl ether / maleic anhydride ), Polyvinylpyrrolidone, water-soluble starch, glue, gelation (gelation), water-soluble alginates such as sodium or potassium alginate, casein, agar and natural and artificial gums such as arabic omega and tragacanth. All of these substances are used in the case of conventional

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Emulsion polymerizations used amounts used, d. H. in amounts usually about 0.1 to 2 ji by weight of the Polymer emulsion.

Working at a special, increased or decreased temperature or in a special temperature range is at making the monomer pre-emulsion unnecessary, and in most, if not all cases, the monoiner pre-emulsion becomes at or near room temperature (about 25 ° C).

The monomer (s) in the pre-emulsion will be by means of a catalytic amount or conventional amount of a conventional free radical polymerization catalyst or -katalysatorsysteras (also called addition polymerization ^ - catalyst, vinyl polymerization catalyst or polymerization exciter or initiator) polymerized, which is preferably essentially water-soluble, without however, that this is a condition. Such catalysts include inorganic peroxides, such as hydrogen peroxide, Alkali (e.g. sodium, potassium or lithium) and ammonium persulfates, perphosphates and perborates, azonitriles, such as "^," '- Azobisisobutyronitrile, and redox systems, including of combinations such as mixtures of hydrogen peroxide, tert-butyl hydroperoxide or the like and an iron salt, one Titanium (III) salt, of zinc form & ldehyde sulfoxylate or sodium formaldehyde sulfoxylate, an alkali or ammonium persulfate, borate or perchlorate together with an alkali metal bisul fit like sodium metabisulphite, an alkali persulphate

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with an arylphosphinic acid such as benzenephosphinic acid, and like that.

In accordance with customary practice, the polymerization catalyst is used only in the amount which is necessary to achieve essentially complete monomer conversion with low catalyst costs. So you can ss. B. with about 0.3 to 0.5 wt. Ji of a perchlorate, such as ammonium perchlorate, together with an approximately equal amount of a bisulfite, such as sodium metabisulfite, preferably about 0.4 Qew. % of the perchlorate together with about 0.4% by weight of the bisulfite, based in each case on the total weight of the honeycomb pre-emulsion, work.

While the total amount of the polymerization catalyst used is apart from the rule that an amount sufficient to ensure an essentially complete conversion should be used, it should be in the water to which the monomer pre-emulsion is added, before the first portion of the Monomer preJ-sion is preferably at least about 10 % of the total amount of catalyst used, in particular about 15 to 20%, in order to ensure good conversion into stable polymer emulsions with an optimal solids content.

When working with redox catalyst systems, it is also possible to use the oxidizing agent, e.g. B. ammonium persulfate, before Formation of the monomer pre-emulsion to dissolve in the mixture of surfactants and water and then the reduction-

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medium together with the oxidizing agent-containing monomer pre-emulsion add to the water in which the polymerization takes place.

The polymerization stage of the process according to the invention is, as mentioned above, carried out by adding the pre-emulsion to water in portions or continuously, the remainder of the catalyst or catalyst system preferably being added at the same time

The amount of water to which the pre-emulsion is added is determined by the desired chemical content of the final polymer emulsion. So z. Example, when preparing a polymer emulsion of 70% Peststoffgehalt the present in the system water total amount (of water from the monomer pre-emulsion, catalyst, and even in © inigan cases dsm surfactant) about 30 wt.% Of the total Polyraai ^ mulsien, a polymer emulsion of 60 JIi solids content HO Qsv.% Etc.

The polymerization temperature is generally room temperature or below to about 80 ° C or above, and preferably about 30 to 60 ° C, and may increase with the progress of the polymerization can also be varied up to essentially complete polymerization. The polymerization can be complete or partly be carried out at reduced pressure, atmospheric or elevated pressure, and depending on the monomers and the catalyst the reaction can, if desired, also in an inert atmosphere, e.g. B. under inert nitrogen or carbon dioxide, be performed. So z. B. polymerizations

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Temperatures carried out 10 ° C or more _s are typically below the boiling point of the lowest boiling, present monomers in an inert atmosphere.

The time at which the monomer pre-emulsion and the catalyst are added to the water in which the polymerization takes place, as well as the total reaction time, can vary depending on factors such as the temperatures and pressures used, the monomers and catalysts present, the desired conversion and pesticide content. Prosentsätsen etc. vary widely. In general, however, the monomer pre-emulsion dsm water is added at such a rate that the polymerization takes place continuously without accumulation of unreacted monomer. For example, be achieved by the monomer pre-emulsion to the water over a period of about 2 to 8 h. Or more, preferably about ^l i to 6 hours, adding _s, wherein the catalyst, usually in aqueous solution with a concentration in the range of About 3 to 12% by weight , based on the total weight of the catalyst solution, is added simultaneously with the monomer pre-emulsion, ie if the monomer pre-emulsion is fed in over the course of β hours, the catalyst solution is introduced at approximately the same time. Small amounts of the catalyst solution can, however, also be added after the introduction of the last portion of the monomer Vorerauloion in order to ensure an essentially complete polymerization, which is especially true in cases where small amounts, e.g. B. up to about 0.5 % of the total weight of the monomers present, having an odor

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Monomers such as ethyl acrylate, butyl acrylate or the like, remain unpolymerized.

After the last portion of the monomer pre-emulsion and the catalyst have been added, the polymer emulsion can be worked up by all customary methods. In general treated with a base, e.g. B. aqueous sodium hydroxide solution or aqueous ammonium hydroxide to remove any to neutralize acidic material, such as acidic monomers or catalyst residues. In general, enough base is added over the course of about 30 to 90 minutes with stirring to obtain a Achieve and maintain a pH of about 7.5 to 10, preferably about 8 to 9 *. The neutralized emulsions are usually allowed to cool to room temperature and then filtered, if necessary, before being used.

Apart from their suitability for paints, the new polymer emulsions of high solids content obtained according to the invention can also be used for continuous sheet or film formation, since these emulsions having a low water content can be dried quickly. The emulsions can also be used for the production of elastomers, crosslinkable sealing and sealing compounds and adhesives and foams as well as in emulsion pinning processes. Monomer pre-emulsions of very high monomer content, e.g. B. with a monomer content of the GsOsa arrangement of about 65 to 70 % or more, are also particularly suitable for continuous emulsion processes, in the case of 4en di.e monomer pre-emulsion by a Re & J-.fcion device in which

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the polymerization takes place, is pressed, the finished polymer emulsion from the exit end, the reaction device largely in the manner of extruding toothpaste from a tube will.

The concept of "verarbsitbaren viscosity" or "usable viscosity" referred to used herein, that portion of the latex polymer Viscositatgmerten high Peststoffgehalts in which an effective © preparation or use of this Lat © xp © lyra © ren _r ά. H. mixing, pumping, pouring, etc., is possible. These ranges include viscosities that are only slightly above the viscosity of water up to values as high as 20,000 sP. In various cases, a viscosity of 50 to 5000 P is preferred. The term "stable latex polymer" as used here denotes the product emulsion polymer, since its emulsion properties are retained for at least one day and preferably for a long time, such as 6 months and more.

Another and essentially unexplained phenomenon which occurs in the polymer emulsions obtained by the process according to the invention and particularly acrylic resin emulsions in that the emulsions are generally nacreous and have a strongly colored appearance and, depending on the type of lighting and the viewing angle, all the colors of the visible Show the spectrum.

The following example ©, in which parts and percentages are unless otherwise stated, based on weight, serve

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This is an explanation of the invention, but without this

artf i * i © basehrSrakt is.

£ 1 © BesfeiK33Ki®g®iii ii «p in üeii examples mentioned viscosity * ΐθΐφ. ¥: let suit ®iin @ m Vissosisiötax ^{11 of} the Brookfield type, model RVW _S & ii esi; li! FE; ®t ^ 2i f ^ ob ® «dws' ^ fog® leads wo ^ d ^ n, which some ^: - i; j'ß gt: © lis; üigeiasis © n ^ nrdeia, until you see the © initially high Viseö ^ ifeät au.f eia © n iai®clrIg © reB value had stabilized, whereby the BestisffiMiigfMi, fsdöeh were carried out in all cases before a possible withdrawal.

B © i η ρ

do you mix the fol ß ^ i * m Μ &'«; ©? ί4 & Μ © ϊΐ« nte? Stir ©. «To room temperature:

Parts

Ifeh ^ isrylate 370.8

Ms thyetherylate 198.4

Medium (ethoxylating 23.0

& 33 ?, higher, with; öhlorswlfonsäiire aulfosaiertex » und irdfc liaferfurohydrosid jri-öuti*alls.lert@r Fet fe & lkohol, Mol» gew. 200D to 2S00, solids content 33.5 ^ J ^{! I} 18 "S ⁿ d © r Aleolae Chemical

welt ^ rea surface active fö-a mean 47.0

Cittit-similar admixture sec ^ wng ^ ind Äfenlichara molecular weight as daa ¹ St eilende means solids content % i "Abex 26-S" of the Aleolae Corporation)

55.8

- 2h -

109853/1511

BATH ORIGINAL

In addition, two catalyst solutions are prepared, the first of which Jj parts of ammonium persulfate in 60 parts deionized in water and further * »parts of sodium mefcabisulphite in 60 parts of deionized Contains water.

177au parts of deionized water are then introduced into a reaction vessel under nitrogen, and the mixture is heated for 30 min 80 ° G with stirring and then cools to 50 ° C, then put 10 parts of the above-mentioned catalyst solutions into the container and then begins with the addition: the monomer mixture and catalyst solutions obtained in the above manner, the emulsion with i80 parts / hour. and the catalyst

solutions with 12 lbs / hour each. zuetast so that the addition the monomer pre-emulsions and the catalyst solutions approximately takes place during the same time. During these additions and one hour after the addition is complete, stirring is continued and the temperature of the polymerization mixture is continued kept at 50 ° C. The emulsion is finally at Ramntemperature allowed to cool and then with aqueous ammonium hydroxide Stallt to a pH of about 8.5.

The olefin emulsion obtained in this way has the following characteristics:

Solid content, £., 60 (after 3 20
no exit Viecoeität, cP 200 mechanical resistance on dam
Waring-Miocher, Min. 2 i} 2 Set time, days unlimited
Days
setting) 38 Movie clarity clear Inherent viscosity (in acetic acid ) ι, TeiIshengrösee, Mikron 0,

(after

C -... A
Example 2

The procedure of Example 1 is repeated exactly with the following changes:

First, the monomer pre-emulsion is prepared using the following materials;

Parts

Ethyl acrylate methyl methacrylate "Abex 18-S" "Abex 26-S" deionized water

403.3

215.9

23.0

Second, the monomer pre-emulsion obtained in this way is added, see below 118.0 parts deionized water (instead of 177.0 parts) added.

The polymer emulsion thus obtained has the following characteristics:

Solids content, % viscosity, cP

Film clarity

17,000
unlimited clear

Example 3

The work Bwei «2 'by Beispi ©! l will be exact with the following Changes wi @ d © rh © lt:

The production of the monomer pre-emulsion is carried out using of the following materials:

- ■■■■.; ■■■ - 26 ■■ -. '■■. ■ ..

109853/1511 ORIGINAL BATHROOM

Parts of ethyl acrylate 370.6

Methyl methacrylate

surfactant (sodium 82.1

octylphenylpolyäthsreulfonat with

a content of 2 to 3 Xthylenoxy-

Units; Feetoffstoff 28 Ji; "" Triton

X-200 "from Rohm & Haas Co .;

deionized water 42.3

The monomer pre-emulsion obtained in this way is added to 18S ₉ 8 parts of deionized water. The resulting polymer emulsion has the following characteristics:

Fuel content >% 60

Viscosity, cP 75

Weaning time, days 170

Film clarity clear

Example ^

The procedure of Example 3 is exactly as follows Repeated amendments:

The monomer pre-emulsion is formed using the the following materials:

Part Ie

Ethyl acrylate 136.0

Methyl methacrylate 233 »0

"Triton X-200" 82.1

deionized water 61.2

The catalyst solutions contain k parts of ammonium persulfate in parts of deionized water or k parts of sodium bisulfite in 30 parts of deionized water.

* ■ G 9 fr

5 /? M S

c -... A tt

The monomer pre-emulsion is deionized to 119.7 parts Added water, the previously with 5 parts of the above Catalyst solutions have been added.

The resulting polymer emulsion has the following characteristics:

Solids content, X-. 70 _:

Vlsoositat, cP 800

. Absetsseit, days. ■ '270

Pilin clarity clear

BVl_ipie.; I - -5 -

The procedure of example 3 will exactly match @ ra @ wt folgesid @ egg amendments w ?,

The formation of the Monemsr-Yoresralsion takes place under.Einsats

Parts

Xthylaevylate -.463.6

Meth ^ lmethaerjlat 25O ₈ ¹ J

"Triton X-20Q · ¹ 82 1

deionized water 70.2

The catalyst solution contains ^ parts of ammonium persulphate in 35 parts © nfeionisisrtem water bsw. -4 parts of sodium metabisulphite in 35 parts of deionized water.

The monomer pre-emulsion is 50.7 parts deionized Added water that was previously mixed with 5 parts of the above Catalyst solutions has been added.

- 28 -

109S53 / 151J

c- .. .A 5 "

The resulting polymer emulsion has the following characteristics:

Pest content, % 75

Viscosity, eP 15 OQO

Weaning time, days 270

Film clarity clear

example

The operation of Example i is again exactly with the following Repeated amendments:

The formation of the monomer pre-emulsion takes place using of the following materials:

Parts

Vinyl acetate

Ethyl acrylate 91.8

Dioctyl maleate 30.7

"Abex 18-S" 30.7

"Abex 26-S" 52.7

deionized water 53.3

The catalyst solutions contain 4 parts of ammonium persulfate in 30 parts of deionized water bsw. ή Part © 'Sodium metabisulphite in 30 parts of deionized water.

The monomer pre-emulsion is deionized to 163.7 parts Added water to which 5 parts of each of the above-mentioned catalyst solutions had previously been added.

The resulting polymer emulsion has the following characteristics:

- 29 -

109853/1511 BAD ORlIlNAL

Solids content see .Jf viscosity, cP
Absefczseit, days
Filraklarheifc

65,000

unlimited clear

Be i a ρ .IeI 7 ■

The operation of Example 1 repeating amendments :

Education ö © r

g @ nau mit'den f © 1

pypy with a Se

stop at ⁴ IO Äfchylenosqr-Einheifeeii, festival. material content 10 $ i "Triton'X ^ ^H Rohm & Haas Ce.)

takes place under Eineats -der

Parts

3T0.8.

198, * p

32.6

The -Konomer-Vor®mulsion ₈ Water "added". ;. .-:

The resulting Folymeremulsi © ^ has - "following®'-characteristic values"

Vesity

mechanical resistance (a 10 tfaring ~ Mis®her) ₉ min. Movie clarity clear

109853/1511 ORIGINAL BATHROOM

■ AWtOao K

¹ C -... A

At s ρ i m 1

The way of working changes repeated

The formation of the Mon®m @ r ° the following materials:

Methyl methacr ^ lat "Triton X-

Part ©

133.4

231.9

, 0 ·

The catalyst solutions contain H parts

in 30 parts
sulfite in 30 parts

Parts of sodium metabolism

good water "

The Monoraer pre-emulsion is _{added to 120 9} β parts of deionized water, which has been -werset ^ -t with 5 parts of each of the above catalyst solutions.

The resulting Polynseremulsiosi has the following characteristics:

Pesticide content, Viscosity, eP set time, days Pilifl clarity

000 unlimited clear

Example <?

The following are used to prepare a monomer emulsion Materials while stirring at room temperature:

- 31 -

109853/151 1

bath

S— ■ · «» A, ■. _:

' ^: ^ ^: Parts

Vinyl acetate 598.3 S

"Igepal CO 897"^; 22.5 g

'»Xgepal SO 63Ο".; ZJ g

deionized water ito, 3 g

Hydroxymethy! Cellulose- ■ 5.0 g:

The "Xgepal CO 6'3O" is the reaction product of nonylphenol and ethylene oxide, which forms a nonionic. Materials 9 Mon! Ethylene oxide added on per mole of nonylphenol have been ».-.'.-. ■

The "Igepal CQ 897". represents a product similar to that "Igepal CO 630", but which has ^ O moles of ethylene oxide.

Furthermore, a catalyst solution is set "- that contains h g p Ammonima · © rralfat and 120 g of water. -..'.-

The reaction medium in a reaction vessel contains 80 g of water and 20 g of the aramonium persulfate described above. The reaction medium; is kept at 75 ° C © rhitat and at this temperature. The 'pre-emulsion' and 'the remaining' catalyst solution: are separated from the reaction medium and continuously at the same rate over the course of M hours.

The resulting latex polymer has the following properties:

Solids content, %. »62.7

Viscosity, cP 90

- 32 -

109853/151 1 BATH

Example 10

To produce a M © n © m®r- ¥ © remul © i © a, the following materials are mixed at room temperature with stirring:

Parts

Vinyl acetate 538 ₃ 6 g

Dioetylraaleate 95.1 g

«Afcex 18-S ¹ * 9.5 g

"Abex 26-S" 15, ο g

Deionized water 106.7 g

Furthermore, two catalyst solutions are recognized ,, whose only © k. g aoraoniurapersulfate in 60 g, deionized. Water and two 4 g of sodium metabisulphite in 60 g of deionized water.

Then 106 _S 7 Z of ionized water are introduced into the reaction vessel under stirring ice ^{and heated to 50 °} C., whereupon 10 g of each of the above catalyst solutions are added and the remaining catalyst solutions obtained in the above manner are then added zuföhrt in separate streams, wherein the Sufühs? UügsgeseSiwiowIgköit each stream is directed so that it is a gleiehraäsaig © feeding a Zeiteaura of SFCD h. gets · During this Outsuführung wad a Stund® NaOH .Beendigung the feeding, stirring was continued UNAE the temperature of the polymerization mixture is kept at 50 ° C. The emulsion is finally allowed to cool to room temperature .

The polym @ r @ mul © t @ n accruing has the following

109853/1511

Feetfeoff content, % 63.9

Viscosity, <3P * ■ ^ βθΟ

inherent ViseosüLfifc. 1.53

10 9853/15

Claims (1)

Pat en tans ρ r -tt. ο h e 1. A process for the preparation of aqueous emulsions with a high solids content, characterized in that using at least one polymerizable * monomer capable of forming a stable emulsion in water "contains at least one ethylene-unsaturated group, in the presence of a stable pre-emulsion and subsequently a permanent one Latex polymers in corresponding amounts of at least one surface-active agent forms an aqueous pre-emulsion which contains in an amount in the range from about 6 to 25% by weight , based on the total monomer present in the pre-emulsion; the pre-emulsion continuously adds to a reaction medium * which is part of the water not required to form the pre-emulsion, but necessary to achieve the desired solids content in the finished product, and a portion of a free-radical polymerization catalyst to stimulate the polymerization of the or at least one of the polymerizable monomers in the pre-emulsion contains appropriate amounts, the reaction medium being kept at the excitation and continuation of the polymerization reaction temperatures and the rate of addition of the pre-emulsion 109853/1511 is steered in such a way that an im. results in substantial complete conversion of the monomer into the latex polymer with its addition, and polymerization in the presence of a sufficient amount of a free radical polymer! sat ionic catalyst in the reaction medium takes place that an essentially complete conversion of the monomer occurs with the formation of a latex processable viscosity with a total content of pesticides in the range of about 50 to 75 % » 2β method according to claim 1, characterized in that one in the pre-emulsion water in an amount of about 10 to 25% based on the weight of the total monomer (s) present, used. 3 · The method according to claim 2 * characterized in that one the free radical polymerization catalyst to the reaction medium separately In a separate stream at sufficient speed that one essentially feeds complete conversion of the monomer into the latex in bulk its addition to form a process viscosity latex polymer with a total pesticide content of about- ^ Sa to 75 ^ occurs. -36- .A 3? Process according to Claim J _9, characterized in that at least about 10% of the total amount of the free radical polymerization catalyst is present in the reaction medium before the addition of the pre-emulsion. 5ο method according to claim h _s characterized in that φ is formed from the polymerizable monomer a homopolymer. The method of claim 5s characterized _s that as a homopolymer or an acrylic "Metha & rylpolymeres forms. 7. The method according to claim 5 *, characterized in that vinyl acetate is used as the polymerizable monomer " 8. The method according to claim k _s, characterized in that a copolymer was formed using polymerizable monomers 9. The method of claim 8, characterized in that _s is a mixed polymer of vinyl acetate and a polymerizable monomer containing a Sthylenungesättigte group forms " BADORIGINAt 10. The method naoh claim 8 * characterized in that dioctyl maleate is used as the polymerizable monomer . • 11. Process according to Claim 8, characterized in that an acrylic or asthpcryl-containing copolymer is used formed 12. The method of claim 11 _s characterized in that it forms a mixed polymer with a content of more than about 50 #i, based on the total weight of the monomers used, of at least one alkyl acrylate or "meta" methacrylate. 13ο The method according to claim 12, characterized in that a copolymer containing ethyl acrylate and methyl methacrylate is formed. 14 “Process according to claim 11, characterized in that a mixed polymer is formed with a content of about 0.01 to 6 %, based on the total weight of the monomers used, of a crosslinking monomer. 15ο The method according to claim 14, characterized in that a vinyl acetate * ethyl acrylate and dioctyl maleate are - 38 -109853/1511 holding copolymer forms. 16. The method according to claim 3 * characterized in »that an anionic surfactant is used 17. The method according to claim 3 » characterized in that a nonionic, surface-active agent is used - 59- 109853/1511