JPH04503224A - Sterically stabilized aqueous polymer dispersions - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Sterically Stabilized Aqueous Polymer Dispersions The present invention is directed to radically polymerized ethylene sterically stabilized aqueous dispersions of polymers based on unsaturated monomers, Regarding its manufacture and its use as a film-forming agent, for example for the manufacture of coatings. It is.

Polymer dispersions generally contain a relatively small proportion of With solvents (dispersion media), it is possible to achieve surprisingly high solids contents at relatively low processing viscosities. It has the advantage that polymer preparations can be used. At this time, the solvent The smaller amount required meets the requirements of maintaining air purity.

Increasingly stringent air cleanliness maintenance regulations and cost planning are However, it is possible to abandon organic solvents altogether and instead use environmentally friendly, environmentally friendly solutions. This ultimately leads to development that uses cheaper water.

Aqueous polymer dispersions are often described and used in final products, e.g. coatings. They are also increasingly being used where higher demands are made.

When adopting aqueous polymer dispersions, the question of stability of this dispersion plays a central role. played. Generally, the dispersion particles solidify and precipitate after standing for a relatively short period of time.

In the meantime, storage-stable polymer dispersions with usable storage stability can be used freely. A particular problem in this case is (generally anionic emulsifiers, protective colloids or so-called internal stabilizers are applied. harmonization in a reasonable way, and this can be done more or less experimentally. It was. Of course, the results that can be used in this case include emulsifiers as well as protective colloids and internal Stabilizers are also mostly useful only when they have relatively strongly polarized to ionic groups. It will be done. In this case, the stabilization must be carried out especially when the particles of the dispersion are polarized in the same direction on the surface. Based on electrostatic repulsion of directed charges. Therefore, dispersion systems stabilized in this way naturally has two important drawbacks: It is extremely sensitive to electrolyte-additives with regard to its stability.

The shaped bodies produced therefrom, for example lacquer films, are relatively resistant to aqueous external influences. It is unstable.

Disadvantages of the latter include, for example, post-production and evaporation of the dispersion medium from this aqueous polymer dispersion. After that, a completely uniform layer is not produced, but rather an uneven and uneven layer due to insufficient fusion. The honeycomb structure previously provided by the dispersed particles remains, resulting in polarization. It is clearly caused by At the interface of this honeycomb, there are emulsifiers and protective colloids. Or the polar to ionic initial stability atomic group of the internal stabilizer (Gruppier ung) is enriched, and at this time, along this hydrophilic interfacial structure, a small amount of Slightly polar substances of molecular weight, such as water, can be dispersed and the coating can then be used. becomes. Furthermore, the emulsifier used in each case is applied to the surface of the coating along the convergence plane of this bee. It may migrate (lead) or migrate to the support. In the first case the surface is undesirable has a viscosity of

There was therefore a need for stable aqueous polymer dispersions that did not have these drawbacks. . The problem that arises from this is that, according to the present invention, the ethylenic unsaturated Sterically stabilized milk based polymers and protective colloids based on Japanese monomers The solution is an aqueous dispersion containing no oxidizing agent, which (1) the dispersion is virtually free of organic solvents, and (2) the protective colloid is essentially ethyl Essentially hydrophobic chains based on unsaturated monomers and free radicals Consisting of essentially saturated water-soluble or water-dispersible polymers that are soft-polymerized and (3) the protective colloid is characterized in that it does not essentially have an ionic group.

Therefore, the interface between the dispersed particles and the aqueous medium has essentially no ionic groups; A stable dispersion is used, the stabilization of which is due solely to steric effects.

Sterically stabilized aqueous content of polymers based on ethylenically unsaturated monomers The method for manufacturing the dispersion is also described in United States Patent No. 4,453,261. Ru. According to this publication, steric stabilizing aids are used in particular for certain grafted polymers. It may be. Preparation of graft polymers, as further cited from this publication. Preferably, only the polymerization of ethylenically unsaturated monomers is important during the , a long-chain hydrophilic monomer and a short-chain hydrophobic monomer have hydrophilic side chains. Becomes the main chain. During the production of the protective colloid according to the invention, all (behaving differently: this In this case, grafting in a narrower sense is important, and in that case, radicals are added to the saturated polymer. The formation of reactive centers results in the formation of hydrophobic side chains on the hydrophilic main chain. will be accomplished.

Advantageous protective colloid side chains are described in US Pat. No. 4,453,261. According to the book, that of the protective colloid according to the invention is directed accordingly towards the aqueous phase, whereas that of the protective colloid according to the invention towards the inside of the scattered particles. Therefore, essentially different dispersed particle-structures exist and are stable. U.S. Pat. No. 4,453,261 discloses that the dispersion according to the invention organic, water-compatible solvents as specified in the specification to obtain stable dispersions in practice. or for further processing, e.g. into usable coating films. No need to add. All (obviously, US Pat. No. 4,453,261) According to the specification, in order to increase the mobility of the polymer by swelling it in the dispersed particles. and thus sufficient dispersion stability, but equally sufficient particle fusion to produce a thin film. In order to achieve this, a considerable amount of solvent is required in the dispersion. On the contrary In the dispersion particles according to the present invention, the function of this solvent is transferred to the inside of the particles. The aqueous side chain is already assumed and therefore an additional coalescing aid (Koaleszen) zhilfs-■1ttel) is not required.

The sterically stabilized aqueous polymer dispersions according to the invention are therefore environmentally friendly, In short, it is actually more advantageous for maximum demands on coating systems that are as completely solvent-free as possible. and more uncompromisingly.

Similarly, JP-A-55-161806 discloses emulsification of ethylenically unsaturated monomers. Grafted with acrylate monomer as protective colloid for polymerization Describes hydrophilic polymers. At this time, modified starch is produced by graft polymerization. substances act as protective colloids. Few selected ethylenically unsaturated monomers Not just usable water based on actually expanded monomer spectrum This should be achieved with this protective colloid so that a polymer dispersion can be prepared. be. However, in addition to the graft-polymerized hydrophobic monomers according to the invention, The graft-polymerized monomer according to the specification of 1983-161806 is used therein. As is clear from the chemical general formula listed, it is a hydrophilic acrylate.

Therefore, the protective colloid according to US Pat. No. 4,453,261 As in the case of The side chains formed in the dispersion are directed towards the aqueous phase: thus the alternative stabilization according to the invention This is exactly the result for the dispersion prepared (for this US patent specification). (see details).

In other respects, the object of JP-A-55-161806 is that the present invention It also depends on the presence of an emulsifier with an ionic charge - according to Rikiki's invention. For the reasons mentioned above, emulsifiers of this type are abandoned.

Therefore, emulsifier-containing dispersions of this type are sufficiently electrolyte-stable or obtainable from them. The thin films produced are not expected to be stable in aqueous media. This polyac Regarding the characteristics of rylate dispersion and its use, JP-A-55-161806 The specification does not mention anything beyond storage stability. others, It turns out that the experimental examples listed in the specification of this patent application are impossible; The graft polymerized starch products A-C produced by the operating method described above are In the emulsion polymerization of ethylhexyl acrylate according to the operating method described in the specification of the patent application Neither did the inventive embodiment of the emulsion polymerization result in a stable dispersion. .

By using the protective colloid according to the invention, a stable fraction is obtained which results in binding during emulsion polymerization. without special ionic emulsifiers, which apparently cannot be abandoned as a prerequisite for obtaining dispersions. It was quite surprising that a stable dispersion could actually be obtained.

In this capacity, ordinary emulsion stabilizers with surface-active properties are considered as "emulsifiers". It should be understood that the protective colloid has the action of a thickening agent and is certainly a protective colloid here. It is not a stabilizer as otherwise expressed as (R6mpps Chenie-Lexikon), 8th edition, 1981, (See classification of emulsifiers on page 1126).

The protective colloid that sterically stabilizes the aqueous polymer dispersion according to the invention is a water-soluble or a protective colloid-precursor which may be a water-dispersible natural or synthetic polymer. It is formed by graft polymerization. Such protective colloids - precursors Examples include polysaccharides and ethylenically unsaturated monomers which are advantageously prepared according to the invention. It's Ma.

Naturally occurring, unmodified polysaccharides can advantageously be used. advantageous natural product polysaccharides or natural substances containing them are poly-alpha-glyoses, e.g. Powder, amylose, amylopectin, dextrin, dextran and pullulan ( polygalactoses, such as arabic agar, tragacanth, carrageenin and pectin and polymannoses, such as Carubin, Taragoummi, algin, alginic acid and guar r) (galactomannose).

As a protective colloid precursor in polymers composed of ethylenically unsaturated monomers In particular polyvinyl compounds and among them especially polyvinylpyrrolidone and polyvinylalcohol It turns out that lucor is suitable.

Polymer molecular weight (Polymergevict) 10000-5oooooo o and especially a polymer having from 50,000 to 500,000 is a protective colloid precursor It is advantageous as

Hydrophobic in nature, capable of graft polymerization onto protective colloid precursors with the formation of hydrophobic side chains as a radically activated ethylenically unsaturated monomer in saturated polymers. What is important is what can be added to the center. This type of monomer is suitable for graft polymerization. In particular, alkyl esters of acrylic acid or methacrylic acid, methacrylic acid bases, dialkyl esters, itaconic acid, maleic acid or fumaric acid; Acrylonitrile or methacrylonitrile, styrene or 1 to 4 carbon atoms styrene compounds substituted by an alkyl group having or by one chlorine atom from the group of vinyl esters of aliphatic carboxylic acids having 2 to 12 carbon atoms It is the selected one. of the aforementioned esters and substituted styrene compounds. Alkyl groups may be straight chain or branched. The above graft polymerization monomer is used alone Graft polymerization can be carried out either by mixing or by graft polymerization. However, free unsaturated acids, especially acrylic Hydroxylic acid or methacrylic acid, acrylamide or methacrylamide are also As well as lykyl acrylate or methacrylate, each of the above seven substances may be used in small proportions. It can be advantageously used in combination with one or several types of polymers.

The above-mentioned alkyl esters of acrylic acid and methacrylic acid and the above-mentioned L-tyrene series Among the dialkyl esters of unsaturated dicarboxylic acids, 1 to 1 sai in the alkyl group of carbon atoms and especially those with 1 to 8 carbon atoms are preferred. Furthermore, advantageous Graft polymerization - monomers include acrylonitrile, styrene, vinyl doluene vinyl, tertiary-butylstyrene, vinyl acetate or vinyl propionate. Nomar.

In most cases, the monomers that make up the grafted side chains are It is also a monomer involved in the composition of liquid-polymer.

Other advantageous protective colloids are those in which the average length of the grafted side chains is 1 0 to 100 monomer units or the average number of grafted side chains is 50 to 1000 per main chain of the protective colloid.

The polymer molecular weight of the graft polymer is so high that it is no longer measurable. and therefore the polymer can no longer be dissolved.

For the production of the desired stable polymer dispersions according to the invention, the addition of customary emulsifiers is necessary. No addition is necessary; small amounts of protective colloid are often already sufficient. In other words, mastery In many cases, the usable stability depends on the composition of the graft and emulsion polymers. Less than 1% by weight, based on the total weight of ethylenically unsaturated monomers required for This can already be achieved with protective colloids corresponding to protective colloid precursors. protective roller The upper limit for this proportion of id precursors may vary over a wide range, but economic rationale will or from the standpoint of the desired stability of the resulting lacquer film in aqueous media. The content should not be too high as possible; however, this should be approximately 20% by weight and good. Protective colloids - A particularly advantageous range of proportions is the non-volatile constituents of the polymer dispersion. The amount is 1 to 10% by weight based on the weight of . in the side chain of the graft polymer and milk, respectively. 0.2 to 20% by weight of protective colloid, based on the total weight of monomers in the polymerized polymer. Preference is given to the proportion of precursors, and those of 1 to 10% by weight are particularly preferred.

Ethylenically unsaturated monomers forming the basis for the polymers of the aqueous dispersion according to the invention Its use in homo- or co-polymerization by emulsion polymerization in aqueous media All of the monomers for which the use has already been described or appear possible are actually It is essential. This is explained in the corresponding literature, for example in Boelscher (BOELSCHE). R), “Dispaanonen Sintetischer Hochpoli? - (Di spersionen 5ynthetischer Hochpoly-se rer)”, 1 copy, Springer Publishing (Springer-Verlag) 1 969, or Walson (H, WAR3ON), 'The Application O. Synthetic Resin Emulsions (The Application n of 5ynthetic Re5in Emulsions, Benn Li5tted, London 1972). Many of these monomers In such emulsion polymerization, only homopolymers or copolymers are polymerized. It's coming. During copolymerization, the type and proportion of each comonomer are particularly important for emulsion polymerization. This has an effect on the applicability or stability of the resulting dispersion. However, this Relevant limitations are taken from the state of the art. The choice of monomer is a matter of minutes. The intended application range of the dispersion also depends on the glass transition temperature of the polymer being produced. This can be easily investigated by those skilled in the art. Dispersion according to the invention In particular, the production of coatings is discussed as a possible scope of application for Since thin film formation plays a central role in the range, the thin lacquer film produced is Polymers with a glass transition temperature that satisfactorily meet the requirements set with respect to film formation temperature. The first step is to select a monomer or monomer composition that will serve as a mer.

The components of the dispersion polymer according to the invention can be, for example, the following ethylenically unsaturated radical polymers: Alkyl esters of nialic acid, which may be monomers that can be combined, such as methyl Acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate 2-ethylhexyl acrylate, decyl acrylate and dodecyl acrylate esters, benzyl acrylate, alkyl esters of methacrylic acid, e.g. methacrylate, ethyl methacrylate and butyl methacrylate, itacone Dialkyl esters of acids, methylene malonic acid, maleic acid and fumaric acid, e.g. Diethyl maleate and diethyl fumarate, acrylonitrile, methacrylic Nitrile, acrylamide, methacrylamide, styrene, substituted styro alcohol compounds such as vinyldolol, chlorstyrol and tertiary-butylstyrene vinyl esters of saturated straight-chain or branched-chain carboxylic acids, e.g. vinyl acetate, vinyl propionate, vinyl laurate or vinyl acetate , vinyl ethers such as vinyl isobutyl ether, vinyl chloride, vinyl chloride Den, chloroprene, isoprene, butadiene, ethylene, propylene, 2-butane ten and alpha-olefins with 4 to 12 carbon atoms, stilbenes, crotons Alkyl esters and allyl ethers of acids and cinnamic acids or their monomers A mixture of.

These monomers, like the graft monomers, amide or methacrylamide and hydroxyalkyl-acrylate or methacrylate release of monomers (each in relatively small amounts in admixture with one or more of the monomers mentioned above) may be an unsaturated acid component.

Preferred ethylenically unsaturated monomers are alkyl acrylic or methacrylic acids. esters, dialkyl esters of itaconic acid, maleic acid or fumaric acid, acrylic lunitrile or methacrylnitrile, styrene or with 1 to 4 carbon atoms Styrol compounds substituted by an alkyl group or by one chlorine atom, 2 Vinyl esters of aliphatic carboxylic acids having ~12 carbon atoms or mixtures thereof It consists of a group of compounds. Esters and substituted esters of these preferred monomers The alkyl group of the styrene compound may be straight chain or branched.

For example, products with a high standard in terms of appearance, mechanical properties and resistance to various external influences. Coatings with a quality generally include acrylic and methacrylic compounds alone or is based on polymers such as those based on styrene compounds and/or vinyl esters. containing monomers and therefore within the scope of the present invention special Dispersion polymers were investigated in detail. 1 to 18 carbon atoms of these monomers and especially alkyl esters of acrylic and methacrylic acid having 1 to 8 carbon atoms. Stell, acrylonitrile, acrylamide, methacrylamide, styrene, Methylstyrol, tertiary-butylstyrene, chlorstyrol, vinyl acetate Particular preference is given to vinylpropionate and vinylpropionate or mixtures thereof.

It is also an object of the present invention to produce sterically stabilized aqueous polymers that do not contain emulsifiers. dispersion, which contains one or more radically polymerizable ethylenically unsaturated molecules. Nomer is actually released as a protective colloid and commonly used in an aqueous medium that does not contain organic solvents. Emulsion polymerization is carried out in the presence of a polymerization initiator that generates radicals, and at this time, the protective colloid is not present. qualitatively hydrophobic in nature based on one or more ethylenically unsaturated monomers. an essentially saturated water-soluble or water-soluble compound free-radically grafted with chain (a); consisting of a dispersible polymer (b) and containing essentially no ionic groups; It is characterized by

First of all, a hydrophobic stabilizer based on one or several ethylenically unsaturated monomers (a) into an essentially saturated aqueous or water-dispersible polymer (b). In the presence of a commonly used graft polymerization initiator in an aqueous medium that does not contain organic solvents, , essentially containing ionic groups, by free radical graft polymerization. and then essentially the presence of this protective colloid Alternatively, several radically polymerizable ethylenically unsaturated monomers can actually be mixed with organic solvents. emulsion polymerization in the presence of an initiator that forms free radicals in an aqueous medium without A sterically stabilized emulsifier-free aqueous polymer dispersion characterized by The manufacturing method is advantageous.

Ethylenically unsaturated monomers and activated graft-polymerizable hydrogen-bonds. Graft polymerization reactions known per se with polymers that are ouben-Weyl), Methon der Organischen Hieremi - (llethoden der organfschen Chemie) ” Described in Volume E20 (1987).

Details of emulsion polymerization can also be found in the relevant literature, e.g. Der Organissien Hiemi, volume E20, or Hölscher, “Disper 'Nonen Sintetischer Hochpolymer', Part 1, Spellinger Publishing Cited from 1969.

In the method for producing a polymer dispersion according to the present invention, each with an advantageous retention of ungrafted polymers relative to the total weight of ethylenically unsaturated monomers. 0.5 to 20% by weight and particularly preferably 1 to 10% by weight of protective colloid precursors are used. It is advantageous to

The protective colloid precursor is first prepared in water at room temperature by stirring for several hours and subsequently It can be activated by adding a partial amount of graft initiator at the process temperature. Recommended. Subsequently, graft polymerization of the ethylenically unsaturated monomer and the remaining amount The graft polymerization can be carried out by metering the initiator.

The method according to the invention stabilizes the protective colloid by graft polymerization and sterically. The resulting polymer dispersion is directly processed by emulsion polymerization of ethylenically unsaturated monomers. produced in the same reaction components continuously, without prior isolation of the grafted polymer. It can be advantageously implemented as follows. In this case, the 21-step method is useless. Raft polymerization and emulsion polymerization can be carried out in one reaction vessel.

In another advantageous embodiment, the polymer dispersion is prepared in a one-step process by: i.e. graft polymerization of protective colloid precursors with a graft polymerization initiator until monomer conversion stagnates, and then immediately This is followed by the addition of an initiator for conventional polymerization to produce a dispersion by emulsion polymerization. Replace. As is well known, graft polymerization does not proceed to complete conversion of monomers. In the case of polysaccharides as solid niger raft substrates, this is often (depending on the polymer) Already after conversion of 25-30% of the time, it stagnates.

To carry out emulsion polymerization, this unconverted monomer is released into the reaction mixture. can be placed. However, before switching to emulsion polymerization, for example, It can also be removed therefrom by distillative separation of .

This is especially true when the monomer components of the graft monomer and the emulsion polymer are the same. It is done when it should not be a thing. Therefore, the work loss of monomer separation is In order to avoid The production of remer dispersions is advantageous.

Ethylenically unsaturated monomers may be used alone or in mixtures in the process according to the invention. It can be done. When using monomer mixtures, the various monomers can be charged in advance at the same time. or can be dispensed. However, if various monomers are mixed in time, Charged to the construction process, as well as for grafting reaction and emulsion polymerization. can change the properties of the resulting dispersion within a certain range. can. For example, in each polymerization, a monomer mixture mainly consisting of monomer M or Ml is used. starting with a compound and consisting of monomer M2 or a mixture consisting mainly of monomer M2 The monomer ratio can be changed continuously at this time. (so-called power feed).

The graft polymerization initiators preferred in each case, their amount and type and the method of supplying them are In many cases it depends on the graft polymerization substrate. Usually salts of polyvalent metals and/or peroxides use. Very suitable graft polymerization initiators are, for example, salts of tetravalent cerium. Ru.

Typical initiators for emulsion polymerization are radical formers, such as inorganic peroxides, e.g. For example, hydrogen peroxide or peroxidisulfate ), organic peroxides such as tertiary-butyl-, cumyl- or lauroylperoxy or an azo compound, such as azo-diisobutyronitrile, and together with chain regulators such as mercapto compounds and other conventional polymerization auxiliaries. can do.

Initiators and auxiliaries are used in conventional amounts.

The process according to the invention for preparing aqueous sterically stabilized polymer dispersions is preferably in the range of 100°C, and particularly preferably in the range of 55 to 90°C, and also for graft polymerization. It is carried out both at the time of emulsion polymerization as well as at the time of emulsion polymerization. Temperature - Above the upper limit, bad graphics ft efficiency is expected, polymerization proceeds too quickly and problems can occur during process adjustment.

Below the advantageous lower temperature limit, the polymerization ends too slowly or monomer conversion occurs. no longer guaranteed. For certain reasons relatively low polymerization temperatures must be used unavoidably. If this is the case, it is possible to work with redox initiator systems in a known manner. stomach The choice of polymerization temperature also depends on the individual monomers to be polymerized; must not be below the glass transition temperature of the resulting polymer.

Furthermore, according to the present invention, not only a stable dispersion can be obtained, but also a stable dispersion can be obtained. does not in fact exhibit the disadvantages of the dispersions of the prior art mentioned at the outset and furthermore It was surprising to be characterized by advantageous use properties.

The dispersion according to the invention is stable towards strong electrolytes, e.g. salts of polyvalent cations. I understand that. Addition of iron chloride (■)/calcium chloride never produced precipitation. . In addition, the dispersion liquid must be able to be mixed with strongly alkaline water glass without forming a precipitate. I was able to confirm that. Therefore, the dispersion according to the present invention can be added depending on the purpose of use. There were little difficulties in processing it, especially with polar auxiliaries. dispersion liquid It is also possible, in particular, to be colored.

The solids content, i.e. the proportion of non-volatile components, in the dispersions according to the invention is It is preferably in the range from 40 to 60% by weight, based on the total weight. Too high a percentage will cause the variance There are limitations associated with the fluidity of the liquid. deer Solids proportions of up to 70% are suitable, especially if the dispersion has a correspondingly advantageous particle size distribution. It is entirely possible.

The viscosity of the dispersion according to the invention is in a low range which is advantageous for further processing. This is a part The pn-range of the dispersion medium, but especially the solids content of the dispersion, i.e. non-volatile Depends on the ratio of ingredients. Standard for the production of dispersions within the scope of the research according to the invention - The formulation starts from a solids content of approximately 50% by weight and leads to an acidic dispersion, in which case The viscosity is in the advantageously low range from 18 to lQQmPa-s, and often lQQmP A-s or higher and up to 500 mPa·S can be obtained. In short, the dispersion according to the invention The liquid can be used with conventional application techniques.

The average diameter of the individual particles of the dispersions produced within the scope of the research according to the invention is from 250 to It varies within a range of 2000 nm. This average particle size is required for the dispersion system according to the present invention. They can be easily modified by appropriate polymerization techniques. As is well known, particle size and its distribution are A series of technical characteristics used, e.g. fluidity, Porous support - permeability, fusibility and density and resulting thin film surface smoothness or The average particle size and its distribution in one direction or the other have a certain influence on the gloss. I'm trying to adjust. For example, to obtain a glossy, smooth thin film surface, with the smallest possible average particle size and advantageous distribution of larger and smaller particles. Starting from a dispersion of In short, depending on the technical decisions used, to some extent “dimensional Obtain the dispersion freely cut (Tsuru aβgeschneiderte) Particle size and size fraction in the sterically stabilized dispersion according to the invention that can be The easy changeability of the fabric can be seen in FIGS. 1 and 2. This is Nomer composition (parts by weight), methyl methacrylate 48-butyl acrylate 48- Protective colloid based on methacrylamide 1 - methacrylic acid 1 with standard formulations In addition to guar as a precursor, guar (Fig. 1) or A/Cerium sulfate (■) (Fig. 2) Weight percentage and cerium sulfate (IV) in the container ) in the copolymer dispersion.

From this figure, it can be seen that with a very low proportion of protective colloid-precursor The proportion of graft initiator (Fig. 1; 1% by weight) is determined first by a relatively high average particle size (and The distribution is very wide, but then the proportion increases and the average particle size becomes very small. was obtained with a significantly narrower distribution and finally with a further increasing proportion (>2% by weight) , it is clear that the trend approaches a distribution with two modes. Protective colloid - previous When the proportion of cerium(IV) sulfate is increased at the same time as the proportion of precursor substances (Fig. 2b), In this case, the bimodality is the polarity at both grain sizes. This is particularly noticeable due to the extremely narrow distribution.

As can be seen from the right curves in Figures 2a and 2b, the graph on reception and dispensing rates The distribution of the amount of polymerization initiator also has a significant effect on the size distribution or modality. have an influence. In short, according to the distribution curves in Figures 1 and 2, under certain conditions At the bottom, a very narrow particle size distribution occurs in some parts, so that in reality it can already be called a monodisperse system. What it can do is quite amazing. This is because there are generally many polymer dispersions. have a more or less widely dispersed particle size and are practically monodisperse according to the state of the art. This is because the production of dispersions has been successful only in a few cases: and here too, especially With very special and simplified systems of homopolymers (often styrene) Only successful.

Thin films with smooth surfaces are easily produced from the sterically stabilized dispersion according to the present invention. Manufactured by Vine. Thin film formation and thin film drying (complete curing) ) The fact that in many cases the process progresses relatively quickly already at room temperature is extremely advantageous. And it's amazing. In most cases, sufficient complete curing has already taken place after a few hours.

The lacquer films obtained from the dispersions according to the invention are comparable sterically stabilized. In contrast to thin films from dispersions that do not actually undergo 24-hour water-action (this test) It is found that it is stable against. Therefore, the dispersion according to the invention may also have a lacquer coating. It is suitable as a base for coatings, especially for outdoor use. Already Its processability at room temperature makes it suitable for domestic workers 0-it-yourself)”)-and the painter-to the range of use of the lacquer It is important for

Dispersions in the scope according to the invention do not harden sufficiently at room temperature and therefore have insufficient resistance. In the case of drying thin films, a slightly increased drying temperature, e.g. 50°C, can be used. Improvements can be achieved. The dispersion according to the invention can be used in a thermosetting system (thermosetting). As a system (Ther■-osetting 5yste-) For example, it can also be processed with shielded polyisocyanates or melamine resins. can. Cymel R-type melamine resin (Cymel 325 and Cymel Corresponding experiments using 327) showed that curing temperatures of 80° C. and above, in particular 90-130° C. and 30 minutes at which curing time increased pendulum hardness values (approximately 50-200%) and brought about once. Contains melamine resin, based on graft polymerized cellulose Yellowing is occasionally observed in thin films of dispersions that do not contain water at temperatures above 100°C; Dispersions containing Min resin do not exhibit this yellowing. The dispersion coated with melamine resin is Furthermore, it is possible to predominate on plastic supports, e.g. on polybutylene terephthalate. This resulted in an adhesive coating.

In particular, the realization according to the invention meets the highest demands regarding environmental comfort and workplace hygiene. The demand for lacquers of extremely high quality cannot be met at the same time. In order to obtain the above-mentioned achieved advantages, the quality of the coating must be improved, for example by visual marks. You can understand for yourself that you have to make certain compromises when it comes to elephants. On the other hand, the environment Where acceptable compromises in comfort and workplace hygiene permit this below the highest requirements. In each case, the lacquer quality can be adjusted to the desired degree by corresponding methods customary to those skilled in the art. It can be optimized for For example, within the scope of the present invention, volatile Certain lacquer properties can be improved by the addition of small amounts of organic solvents .

experimental part Standard recipe for the production of aqueous polymer dispersions according to the invention Unless otherwise specified, proceed as follows: Stirrer, reflux condenser, nitrogen inlet tube and Protective colloid precursor 109 was added to distilled water in an IQ flask with a metering device. 400 g under nitrogen. When this dispersion is semi-evaporated, several hours Stir at room temperature for, for example, up to 10 hours in the case of polysaccharides as precursors. Next Heat to 70°C and add 1.9 mV of cerium sulfate dissolved in 70 g of water. and stirred for 1 hour at 70°C. Subsequently, at 70°C, ethylenically unsaturated monomer 4 Cerium(IV) sulfate 4 from the metering device and simultaneously dissolved in water 309 9 from another dosing device for 1 hour.

After a post-reaction time of 1 hour at 70°C, the ammonium finally dissolved in water 209 Feed peroxydisulfate 59 for 10 minutes. Add the contents of the flask for another hour. and then cooled.

The solids content of the aqueous, sterically stabilized polymer dispersion thus obtained is: At 100% conversion of monomer it should be 49.3% by weight.

Unless otherwise specified, protective colloid precursors include Ross (Fa, Rot). h1 Karlsruhe) as guar powder (edible quality) and ethylenically unsaturated monomers. A mixture of the following composition is used: methyl methacrylate 2409/butyl acrylate. Rate 2409/methacrylamide 59/methacrylic acid 5g.

Test solids content/conversion of aqueous polymer dispersions according to the invention.

For the determination of monomer conversion, the proportions of the non-volatile dispersion components are kept constant by weight. This was determined by drying the dispersion at 150°C until 100% Compare with the value calculated for conversion rate.

viscosity: The dynamic viscosity of the polymer dispersion was measured using a rotational viscometer (Haake, Haake). Measured at 20°C in a Viskotester VT"180). Ta.

Storage stability: For this purpose, the dispersions are stored at room temperature or in a so-called rapid test at 50°C and each dispersion is The standing time during which solidification has clearly occurred and the solidified material can no longer be stirred. Recorded. In this rapid test, there was still no precipitation after 30 days of standing time. Dispersions that were otherwise no longer stirrable were rated as extremely stable.

Electrolyte stability: 25 ml of the dispersion to be tested were diluted to 100 mJ and iron(III) chloride and potassium chloride were added. Titrated with a saturated solution of lucium (1:1 weight ratio). When using 25 μl of salt solution A polymer dispersion is considered to be electrolyte stable if no coagulation of the dispersion still occurs. evaluated.

viscosity: The average diameter of the dispersion particles was investigated by turbidity measurements.

The distribution curve for particle size was analyzed using transmission electron microscopy (device TEM-Philips (Ph The automatic image analysis system (equipment Quanti set) Smoke treated with charcoal.

Thin film formation/curing: For evaluation of the thin film forming properties and curing of the coated thin film obtained from the dispersion according to the present invention , this is placed on a glass plate, and a deep-drawn spiral (Tiefziehspiral) is applied on this. ale) to form a 150 μm thick wet film. Room temperature - as well as 50°C - dry The curing progress during drying was measured by measuring thin film curing after 4 hours, 1 day, 15 and 30 days, respectively. The thin film formation was qualitatively evaluated by visual impression (smoothness of the thin film surface and uniformity and transparency of thin films).

A thin film consisting of a mixture of a dispersion according to the invention and a melamine resin was tested in a standard test of 10 It was baked for 30 minutes at 0 and 120°C. This mixture has a dispersion of 10% in the standard test. 0g and Cymel 325 or Cymel 327 (Cyanamide Co., Ltd. (Fa, Cyana) mid)

Thin film hardness The hardness of a thin film on a glass plate is defined as the pendulum hardness by Koenig ( DIN 53157) was measured.

Main test: To investigate the water resistance of thin films, absorbent cotton soaked with tap water was placed on a glass plate. I put it on a thin film and covered it with a clock. After a standing time of 24 hours at room temperature, the thin film (A non-water resistant thin film appears white and cloudy). 1 day and each at room temperature and 50℃ Films cured at room temperature for an additional 29 days were evaluated.

Experimental Examples 1 to 6 and Comparative Examples According to the standard formulation described above, a stable aqueous polyester is prepared using the following commercially available colloidal precursors: A mer dispersion was prepared: 1. Gua (guar powder from Ross, Karlsruhe) 2. Water soluble starch 3. Gum arabic (commercially available) 4. Frankincense (commercially available) 5. Dextran (commercially available) 6. Polyvinylpyrrolidone (PVP-K15 type from GAF) As ethylenically unsaturated monomers, methyl methacrylate (49% by weight), butylene acrylate (49% by weight), methacrylamide (1% by weight) and methacryl Non-sterically stabilized comparison using 490 g of a mixture consisting of acids (1% by weight) The method for preparing the dispersion was carried out as follows: Standard - In a flask equipped as described in the recipe, NatC1' /Lu (Natrosol) 250 L S (Hercules Co., Ltd. as a protective colloid) (Hydroxyethylcellulose of Fa, l1ercules) 4.09,) Triton X 165 (Rohm & Haas) (Fa, Rohm & 1laas) non-ionic emulsifier) 12. Oy and sodium lauryl sulfate 9.0 g of thorium was dissolved and heated to 70°C. Furthermore, the following three types of mixtures are manufactured. l) Monomer mixtures as in Examples 1 to 6: additionally with a chain regulator tertiary-dodecyl mercaptan 4g 2) 4.0 g of ammonium peroxydisulfate in 60 liters of water 3) 4.0 g of subdispersed sodium hydrogen in 60 IIl of water.

10% of each of these three mixtures was added to the contents of the flask heated to 70°C and It was allowed to react for 0 minutes (seed). Next, separate the remaining 90% of the three types of mixture. The flasks were fed to 70° C. from each metering device simultaneously within 2 hours. Then hula The Scot contents were held at 70°C for an additional 2 hours and then cooled.

Essential properties of the polymer dispersions thus obtained and of the lacquer films resulting therefrom are summarized in Tables 1 and 1a.

In all cases high conversions of ethylenically unsaturated monomers are achieved (≧99%) . Despite the dispersion having a pH value in the acidic range and a high solids content, It has a low viscosity, making it suitable for processing into lacquers. The stability of the dispersion when stored at room temperature The quality and average diameter of the dispersion particles will vary depending on the protective colloid precursor used. The results are relatively mixed.

Electron microscopy of sterically stabilized dispersions reveals relatively simple particles with slight agglomeration. Indicates a particle of one size. This type of imaging makes it extremely easy to investigate particle size distribution. can do. In comparison, particles in conventional, non-sterically stabilized dispersions When creating electron micrographs (as was the case in this comparative experiment), strongly agglomerated Therefore, it is not possible to measure the average particle size and its distribution with this method. Ru.

In contrast to the sterically unstabilized dispersions according to the comparative experiments, the stand-up of experiments 1 to 6 Physically stabilized dispersions are prepared in a chamber known to be stable to electrolyte-additives. After drying for 4 hours and 1 day at room temperature and 50°C and a further 29 days only at room temperature. again listed in Table 1a for the pendulum-hardness of lacquer thin films consisting of dispersions of This value indicates that sufficient complete curing has already occurred after several hours and that in most cases The hardness value achieved after one day no longer increases or increases only slightly. It shows that there is. In most cases, hardness values achieved at 50°C are not achieved at room temperature. higher than the value achieved. 50°C - a more favorable film formation when drying the resulting lacquer You can tell by the appearance of the thin film that the thin film dried at 750°C is almost transparent; Most of the thin film dried at room temperature remains white. Not sterically stabilized A sterically stabilized dispersion as opposed to a thin lacquer film consisting of a dispersion (comparative experiment) It is overwhelmingly resistant to water action for 24 hours (Experiment 1. 2°5 and 6).

Experimental examples 7 to 11 Standard - Depending on the formulation, stable polymer dispersions are shown in Table 2 for various seven-mer compositions. ) and 10 g of protective colloid precursor (monomer weight) and 10 g of protective colloid precursor. 2%). The conversion rate and properties of the dispersion are clear from Table 2. That's it. For experiment 8c with vinyl acetate as the comonomer, acedel To resist acidic hydrolysis of the groups, the acidic dispersion was neutralized after polymerization (p H7,5). The dispersions of Runs 8a and 8b proved to be extremely viscous.

with the difference that the solids content was adjusted to about 40% by weight instead of about 49%. , repeating it (almost at 100% monomer conversion) lowers the viscosity. A dispersion was obtained: 8a 480 mPa, s + 8b 570 mPa, s All dispersions are stable to electrolyte addition. Can be dried at room temperature as well as at 50℃ The applied lacquer film proved resistant to water in a 24 hour test.

Experimental examples 12 to 18 Standard - Methyl methacrylate (49% by weight), butyl acrylate depending on formulation (49% by weight), methacrylate amide (1% by weight) and methacrylic acid (1% by weight) %) using a 7-mer composition as shown in Table 3. Polymer dispersions with different proportions of guar as substance were prepared. Gua 10 and At higher proportions by weight, the dispersion becomes extremely viscous. Still In order to obtain a viscous dispersion that can be used with high guar proportions, the solids content of the dispersion must be Adjust the amounts lower, i.e. start from a correspondingly lower monomer water ratio. I had to. That is, in dispersion 17 (10% guar), the solids content is approximately 42 % by weight and for Dispersion 18 (15% guar) it is approximately 26% by weight.

The dispersion is also found to be stable in tests for electrolyte stability. Again in Figure 2 It is shown. As the guar proportion increases, the viscosity-distribution of the dispersion changes significantly. : Dispersions with less than 1% by weight of guar have a broad particle size distribution. Gua A very narrow distribution was recorded at 1% and 1.5% by weight, which was The width increases to 111% and eventually becomes bimodal from a proportion of 4% by weight of guar.

In contrast, dispersions with 10-15% by weight of guar are again monomodal. It has a relatively small and extremely uniform particle size, and at this time automatic image analysis was abandoned. Experimental Examples 19 to 27 where the uniformity was obvious In this experiment, the effect of cerium sulfate (■) on the properties of polymer dispersion and its The effect of time of addition was examined. Guar with increasing proportion of cerium sulfate (rV) It has been found advantageous to also increase the proportion. Experimental conditions and dispersion characteristics They are listed again in Table 4. Unless otherwise stated in this table, standard-formula working . ``Cerium sulfate (TV), which was previously charged, was added before monomer placement. the proportion added (standard - 20% by weight according to the formulation) and "dosed" Cerium (IV) sulfate is metered at the same time as the monomer (but from another metering device). (80% by weight according to standard prescription). From the description in the table Advantageous property - image is inferred. However, according to experiments 19 and 20 (pre-charged In the case of extremely small proportions of cerium (IV) sulfate (only It has high monomer conversion and is stable only up to 13 days in storage at 50°C. A highly viscous dispersion is obtained.

Dispersion stability against electrolyte addition and film stability against water action for 24 hours is good on the gold side.

As can be inferred from Figure 2 for Experiments 21 to 24, the particle size distribution of the dispersion particles The influence of the graft initiator on the V)/guar ratio increases or cerium sulfate (TV) ratio increases. The pi modality increases with

Experimental examples 28 and 29 This experiment is based on a standard recipe, but below the standard temperature of 70°C ( Experiment 28) and production of polymer dispersions at temperatures above 10°C (Experiment 29) Ru. A dispersion having a characteristic profile similar to that of a dispersion produced at 70°C is obtained. . Polymerization at 60°C, on the other hand, results in a conversion of only 88% of the monomer. , deviating from the standard-formulation, ammonium peroxydisulfate 1.5 wt. % (instead of 1% by weight) and polymerization for 3 hours (instead of 2 hours) In addition, the conversion rate can be increased to 98.2%.

Experimental examples 30 to 33 This experiment involved two raw monomers, butyl acrylate and methyl methacrylate. one of which was supplied in excess at the beginning of the deployment and the other in excess at the end of the deployment? or vice versa, relating to the production of stable polymer dispersions with changes in monomer sizing. . In this case, at the beginning of monomer dosing, only one of the raw monomers enters the customary dosing device. , but other monomers were added to this at the same time and within the same placement time of 1 hour. It was carried out as per the standard recipe, with the conditions being added to the dosing device for the first time. this The method uses graft polymers rich in butyl acrylate and methyl methacrylate. Main polymer with high content or graft polymer with high content of methyl methacrylate and It was desired to produce a butyl acrylate rich main polymer.

This experiment is summarized in Table 5. The evaluated basic properties of these polymer dispersions In this case, no significant changes occurred compared to comparable standard-experiments (Experiments 21 and 23). It wasn't. The dispersion is stable to electrolyte addition and prepared from The lacquer film is resistant to water action (main test).

In Experimental Example 34-3 In this experiment, the graft polymer is first produced as usual, then the main polymer is produced. By carrying out the polymerization to form the polymer under the dosage of other monomers, - A dispersion was produced.

In the case of experiment 34, during the preparation of the graft polymer according to the standard formulation (guar 2 wt%, cerium sulfate (N) (2 wt%), only 273 of the total monomer mixture at 1 h After metering and after 1 hour of reaction, ammonium peroxydisulfate - placement of the remaining l/3 of the solution and monomer mixture for 1 hour (separately and simultaneously) It seems that the main polymerization was switched to ammonium peroxydisulfate. I went to

For experiments 35 and 36, the standard formulation (2% by weight guar, sulfur) was used as usual. Cerium acid (■) 2% by weight) was carried out after graft polymerization until the end of the post-reaction. Then, monomers that did not react during the graft polymerization were separated by distillation.

Then the water of the graft polymer thus obtained having a solids content of 16% by weight After heating to 70°C, the other monomer mixture and ammonium pellets were added to the dispersion. The aqueous disulfate solution was fed separately and simultaneously within 1 hour. heavy The model was adjusted such that at the end of the reaction there was a dispersion with a typical solids content of about 49% by weight. The amount of nomer mixture was selected. The proportion of ammonium peroxydisulfate is , usually 1% by weight, based on the weight of the monomers metered. Experiment 35 In this case, the monomer mixture contains 55% by weight of methyl methacrylate, butyl acrylate, 43% by weight of acid, 1% by weight of methacrylate amide and 1% by weight of methacrylic acid. and in the case of experiment 36, 27.5% by weight of methyl methacrylate, butyl 43% by weight of acrylate, 27.5% by weight of styrene, 1% by weight of methacrylamide % and 1% by weight of methacrylic acid.

In the thus obtained stable polymer dispersions 34 to 36, other comparable present invention No significant changes occurred with respect to the basic properties evaluated compared to the polymer dispersions prepared by It wasn't. Its electrolyte-stability as well as the corresponding water action of the lacquer film. Good resistance. We investigated a particularly narrow distribution of dispersion particle-diameters in the dispersion of Experiment 34. , so that in this case one can in fact refer to a monodisperse system.

Experimental example 37 This example concerns the curing of a polymer dispersion according to the invention in the presence of a melamine resin.

For this purpose, the dispersions of Experiments 15, 19, 24, 30 and 33 and the melamine resin Mel 325 and Shimel 327 (Cyanamide Co., Ltd.) were cited. 100g of each dispersion and 25 g of melamine resin were mixed together. The lacquer thin film produced from this Cured at 100° C. for 0 minutes. The film hardness values obtained are listed again in Table 6, and Contrast the hardness values of a thin film dried at room temperature that does not contain melamine resin. 6th For comparison, the table also shows the hardness values of thin films cured at 100℃ without melamine resin. include.

Table 1a: Drying and water resistance of lacquer thin films made from dispersions according to Table 1 Number of two room temperature - drying Lower numbers: 50°C - dry (up to 1 day, then room temperature) 46 45 49 + 2424242 + 49 52 53 + 5212929 + 28 28 32 + 6364545+ Comparative experiment 13 14 17 - Figure 1: Particle size φ (μm)-distribution and non-volatile dispersion composition of dispersion based on tIA quasi-formulation Relationship between parts by weight of protective colloid r-precursor (guar) ≧ Extinction international search report international search report PCT/EP　90100146 SA　M438

Claims (1)

[Claims] 1. Polymers based on radically polymerized ethylenically unsaturated monomers and In sterically stabilized, emulsifier-free aqueous dispersions of protective colloids, (1) the dispersion does not actually contain organic solvent, and (2) the protective colloid is essentially Intrinsically hydrophobic chains based on tyrenic unsaturated monomers and free radical groups consisting of raft polymerized essentially saturated water-soluble or water-dispersible polymers; and (3) the protective colloid essentially contains no ionic groups. A sterically stabilized aqueous polymer dispersion characterized by: 2. Water-soluble or water-dispersible natural or synthetic polymers may be modified or from the group of polymers consisting of unsaturated polysaccharides or ethylenically unsaturated monomers. The dispersion liquid according to claim 1, which is a dispersion liquid according to claim 1. 3. 3. The dispersion according to claim 2, wherein the polysaccharide is a naturally occurring, non-denatured polysaccharide. 4. The polysaccharide is poly-alpha-glucose, polygalactose or polymannose. The dispersion according to claim 2 or 3. 5. Polymers consisting of ethylenically unsaturated monomers include polyvinyl compounds and The component according to claim 2, which is polyvinylpyrrolidone and polyvinyl alcohol. Liquid dispersion. 6. The water-soluble or water-dispersible polymer that produces the protective colloid precursor is remer molecular weight 10,000-5,000,000 and especially 50,000-5,000,000 The dispersion liquid according to any one of claims 1 to 5, having the following. 7. essentially a radical graft polymerization onto a protective colloidal precursor of the polymer Hydrophobic ethylenically unsaturated monomers include acrylic acid and/or methacrylic acid. lukyl ester, benzyl methacrylate, itaconic acid, maleic acid and /or dialkyl ester of fumaric acid, acrylonitrile and/or methacrylic By nitrile, styrene and/or alkyl groups having 1 to 4 carbon atoms or styrene compounds substituted by 1 carbon atom, 2 to 12 carbon atoms a group of vinyl esters of aliphatic carboxylic acids or mixtures of these monomers with 7. The dispersion according to any one of claims 1 to 6, wherein the dispersion is selected from: 8. The alcohol component in the alkyl ester and dialkyl ester is 1 A component according to claim 7 having ~18 carbon atoms and preferably 1 to 8 carbon atoms. Liquid dispersion. 9. Substituted styrene compounds include vinyltoluol, tertiary-butylstyrene and vinyl ester vinyl acetate or vinyl probionate. 7. The dispersion according to 7. 10. The average length of the grafted side chains in the protective colloid is between 10 and 100 mm. 10. The dispersion according to claim 1, which corresponds to the nomeric unit. 11. The average number of grafted side chains is 50 to 1 per protective colloid main chain. 11. Dispersion according to any one of claims 1 to 10, in the range of 000. 12. The proportion of the protective colloid precursor in each case in the side chains of the grafted polymer and 0.5 to 20% by weight, based on the total amount of monomers in the emulsion polymer and advantageously Dispersion according to any one of claims 1 to 11, which is 1 to 10% by weight. 13. Radically polymerized ethylenic unsaturation that forms the basis of polymers in aqueous dispersions Japanese monomers are alkyl esters of acrylic acid and/or methacrylic acid, itaco Dialkyl esters of maleic acid, maleic acid and/or fumaric acid, acrylonitrile and/or methacrylonitrile, styrene and/or having 1 to 4 carbon atoms styrene compounds substituted by an alkyl group or by one chlorine atom, Vinyl esters of aliphatic carboxylic acids having 2 to 12 carbon atoms or these Any one of claims 1 to 12, which is a monomer consisting of a group of mixtures of monomers. Dispersion liquid according to item 1. 14. Ethylenically unsaturated monomers contain 1 to 8 carbon atoms in the alcohol component. alkyl esters and dialkyl esters, vinyltoluol, tertiary-butyl esters, Chlorstyrol, Chlorstyrol, Vinyl acetate, Vinyl propionate and/or vinyl laurate. 15. One or more group-polymerizable ethylenically unsaturated monomers are actually organically soluble. Protective colloids and conventional free radical-generating polymerization in an aqueous medium free of agents. emulsion polymerization in the presence of an initiator, the protective colloid being essentially one or several emulsion polymers; Essentially hydrophobic chains (a) based on tyrenic unsaturated monomers and free radicals essentially saturated water-soluble or water-dispersible polymers that are graft-polymerized - (b) and essentially free of ionic groups. of the sterically stabilized emulsifier-free aqueous polymer dispersion according to item 1. Manufacturing method. 16. First, an essentially sparse solution based on one or several ethylenically unsaturated monomers. The aqueous chain (a) is replaced by an essentially saturated water-soluble or water-dispersible polymer (b). ) on a conventional graft polymerization initiator in an aqueous medium that does not actually contain organic solvents. essentially ionic by free radical graft polymerization in the presence of Preparing a protective colloid containing no groups and then actually determining the presence of this protective colloid In the following, it is assumed that the compound actually contains one or more radically polymerizable ethylenically unsaturated monomers. Emulsification occurs in an aqueous medium without organic solvents and in the presence of free radical-forming polymerization initiators. The sterically stabilized emulsifier according to claim 1, characterized in that it is polymerized. A method for producing an aqueous polymer dispersion containing no. 17. to the total weight of monomers in the side chains of the graft polymer and in the emulsion polymer, respectively. 0.5 to 20% by weight of ungrafted protective colloid precursor and advantageously The aqueous potion according to claim 15 or 16, characterized in that 1 to 10% by weight is used in Method for producing remer dispersion. 20. Graft polymerization for the production of protective colloids and production of polymer dispersions The emulsion polymerization for of the aqueous polymer dispersion according to any one of claims 15 to 19 carried out in Manufacturing method. 21. Aqueous porous according to any one of claims 1 to 20 for the production of coatings. Use of remer dispersions. 18. Production of protective colloids and ethylenically unsaturated monomers by graft polymerization The production of sterically stabilized polymer dispersions by emulsion polymerization has been rapidly linked. Subsequently, the graft polymer can be run in the same reaction components without prior isolation. 17. The method for producing an aqueous polymer dispersion according to claim 15 or 16. 19. Mobilizing the graft polymerization of protective colloid precursors using graft polymerization initiators The polymerization is carried out until the nomer conversion rate stagnates and then immediately the polymerization is started for a conventional polymerization. 19. The method according to claim 18, wherein the addition of an initiator switches to dispersion production by emulsion polymerization. Method.