DE2939897A1 - Aq. polyester and vinyl(idene) polymer dispersion prepn. - by separately dispersing in water, mixing, after-stirring and use as lacquer binder - Google Patents

Abstract

Aq. dispersions, pref. having disperse phase average particle dia. 50-3000 nm, contain as non-volatile constituent, (A) 80-20 wt.% of at least one polyester, (B) 20-80 wt.% of at least one polymer of alpha, beta-ethylenically mono-unsaturated cpds. and (C) 0.5-10 wt.% emulsifier, where the percentages each refer to the sum of (A) and (B). The aq. dispersions are prepd. by separately dispersing (A) and (B) each contg. no more than 1 wt.% condensed-in polyalkylene glycol residues, in aq. phase. The dispersions are mixed at 40-95 (50-80) deg.C. The mixts. are then stirred another 5-180 (10-30) min. at 40-95 (50-80) deg.C. The dispersions are used, esp. as lacquer binders, partic. for stoving lacquers, and opt. in the prodn. of shaped articles and gels. The corrosion-protective activity of polyester/vinyl or vinylidene polymer coatings is increased. The coatings combine the flow, gloss and filling-capacity of (A) with the hardness and stability of (B).

Description

Aqueous dispersions of polyesters and vinyl resp.

Vinylidene polymers, process for their preparation and their use for the production of paints The present invention relates to aqueous dispersions of polyesters and polymers oC, ß-ethylenically monounsaturated compounds, a process for the preparation of these dispersions and their use for the preparation of lacquers, especially stoving lacquers.

Combinations of polyesters and polymersoC, B-ethylenically simple Unsaturated compounds are also referred to below as "binders".

"Aqueous dispersions" are used below to refer to heterogeneous systems understood, which are opaque and in which the organic resin phase in water, preferably with an average particle diameter of 50-3000 nm is. The term "aqueous dispersions" does not include those below Binder solutions that are transparent in the aqueous phase due to salt-forming groups Form solutions; such resins have in the Usually acid numbers 2 40, are pre-dissolved in water-miscible organic solvents and after the neutralization with water to form homogeneous, transparent solutions.

Speak in favor of the increasing use of aqueous dispersions in the paint sector Mainly two reasons: First, they have the advantage that you can use them organic solvent can do without, and secondly they tend - differently the coating agents applied from organic solution - hardly run off on vertical surfaces Areas (see F.

Armitage, L.G. Trace, J. Oil and Color Chemists Assoc. 1957, p. 860).

From DE-OS 2 750 568 aqueous polyester / vinyl or Vinylidene polymer dispersions known. The dispersibility of the components is made by using a polyether polyol in making the polyester and by at least partial neutralization of the carboxyl groups of the vinyl or Vinylidene polymer achieved. The corrosion-inhibiting effect and the adhesion the coatings on metal parts produced by means of these dispersions have proven themselves however, in many cases it has proven to be insufficient.

It has now surprisingly been found that the anti-corrosion Effect of polyester / vinyl or. Vinylidene polymer coatings effective thereby increased can be that one on the incorporation of polyether polyols in the polyester largely, preferably completely, dispensed with, instead in the presence of at least one emulsifier works and both the polyester and the vinyl or vinylidene polymer dispersed separately in water and these aqueous dispersions combined in the heat.

The invention therefore relates to a process for the production of aqueous Dispersions whose non-volatile components essentially consist of A. 80-20, preferably 70-30% by weight of at least one polyester, e.g. 20-80, preferably 30-70% by weight at least one polymer, B-ethylenically monounsaturated compounds and C. 0.5 to 10% by weight of emulsifiers, the percentages being in each case based on the sum of components A and B, characterized in that one Polyester A and polymer B, each of which condensed in at most up to 1% by weight May contain polyalkylene glycol residues, each dispersed separately in the aqueous phase, the dispersions are mixed in the heat in such a way that the mixing temperature is 40-950 ° C., preferably 50-80 ° C, and the resulting mixture is still 5 to 180, preferably 10 to 30 minutes, at 40-95 ° C, preferably 50-80 ° C, stirred.

The invention furthermore relates to the above process available dispersions.

The invention also relates to the use of these dispersions for the production of lacquers, especially stoving lacquers.

The aqueous dispersions according to the invention are stable and can to coatings with excellent corrosion protection and excellent adhesion are processed. These coatings combine the advantages of polyester (e.g. good flow, gloss, filling power) with those of the polymer (e.g.

Hardness, insensitivity to physical and chemical influences).

Polyesters are understood to be known through polycondensation Processes produced from alcohols and carboxylic acids, optionally modified with fatty acids Polycondensates of the type, for example, in Römpp's Chemielexikon, Vol. 1, p. 202, Frankh'sche Verlagsbuchhandlung, Stuttgart, 1966, defined or at D.H. Solomon, The Chemistry of Organic Filmformers, pp. 75-101, John Wiley & Sons Inc. ' New York, 1967, are described.

Alcohols preferred for the synthesis of polyester A are aliphatic, cycloaliphatic and / or araliphatic alcohols with 1 to 6, preferably 2 to 4, OH groups bonded to non-aromatic carbon atoms and 1 to 24 carbon atoms per molecule, e.g. glycols such as ethylene glycol, propylene glycol, butanediols, Neopentyl glycol, trimethylpentanediol-1,3, hexanediols; Ether alcohols such as di- and Triethylene glycols; ethoxylated bisphenols with 2 alkylene oxide residues per molecule; perhydrogenated bisphenols; also trimethylolethane, trimethylolpropane, trimethylolhexane, Glycerin, pentaerythritol, dipentaerythritol, dimethylolcyclohexane, mannitol and sorbitol; monohydric, chain-breaking alcohols such as methanol, propanol, butanol, cyclohexanol, 2-ethyl-hexanol and benzyl alcohol.

Particularly preferred alcohols are neopentyl glycol, trimethylol propane, Dimethylolcyclohexane and perhydrobisphenol.

The polyesters A can contain up to 15% by weight, based on polyester A, Contains monovalent alcohol residues condensed.

For the synthesis of the polyester A preferred acid components are aliphatic, cycloaliphatic, saturated or unsaturated and / or aromatic polybasic carboxylic acids, preferably di- and tricarboxylic acids, with 4 to 12 carbon atoms per molecule or their esterifiable derivatives (e.g. anhydrides or esters), e.g. phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydro and hexahydro phthalic anhydride, Trimellitic anhydride, pyromellitic anhydride, maleic anhydride, fumaric acid, Adipic acid, glutaric acid and succinic anhydride, azelaic acid, endomethylenetetrahydrophthalic acid, also halogenated acids, such as chlorophthalic acids and hexachloro-endomethylenetetrahydrophthalic acid.

Combinations of 10-30 mol% phthalic acid and 70-90 mol% tetrahydrophthalic acid, each based on the dicarboxylic acid used, deserve special mention because they lead to both good storage stabilities and paints that run well.

The polyesters A can be made from polycarboxylic acids and polyalcohols alone being constructed. But it is also possible to do it by condensation of monocarboxylic acids to modify.

Monocarboxylic acids preferred for the production of polyester A are aliphatic, cycloaliphatic, saturated and unsaturated and / or aromatic Monocarboxylic acids with 6 to 35 carbon atoms per molecule such as benzoic acid, butylbenzoic acid, Toluic acid, hexahydrobenzoic acid, abietic acid, lactic acid and fatty acids, their Mixtures and esters of the same such as linseed oil, soybean oil, wood oil, safflower oil, castor oil, Cottonseed oil, peanut oil, tall oil fatty acid, linseed oil fatty acid, soybean oil, wood oil, safflower oil and ricinic fatty acid and from natural, unsaturated oils or Fatty acids obtained by conjugation or isomerization; preferred Saturated fatty acids are, for example, coconut fatty acids, oG-ethylhexanoic acid and isononanoic acid and linear C16-C18 monocarboxylic acids.

Fatty acid-modified polyesters (alkyd resins) lead in the context of Invention of particularly full-bodied coating agents. Particularly preferred fatty acid-modified ones Polyesters A are those with an oil content of 20 to 50, preferably 25 to 40% by weight, calculated as triglyceride and based on polyester A.

Polyester A for polyester dispersions that are used for the production of oven-drying Paints are used, usually get by with an oil content of 0 to 45% by weight. High levels aromatic components of polyester A give the lacquer coating special hardness, high contents of aliphatic components in polyester A give it good elasticity.

The acid number of polyester A is usually between 3 and 35, preferably between 5 and 25.

OH numbers in the range of approx. 100 are appropriate for stoving enamels, while polyester A with lower OH numbers is more suitable for air-drying systems are.

It is possible to have up to 25% of the ester bonds of polyester A through To replace urethane bonds.

The number average molecular weight of polyester A is 800 to 10,000, preferably 1500 to 3000 (up to molecular weights of 5000 by vapor pressure osmometry determined in dioxane and acetone, the lower value if the values differ is considered correct at molecular weights over 5000 by membrane osmometry determined in acetone).

The selection of the type and amount of each to be condensed into polyester A. Raw materials depend on the desired molecular weight and the area of application of the polyester dispersions according to the invention.

The relationships between molecular weight and amount of raw material are in U. Holfort, Farbe und Lack 68 (1962) pp. 513 to 517, pp. 598 to 607, in detail described.

The viscosity of polyester A, measured in accordance with DIN 53 211 (DIN cup 4) as a 50% strength by weight solution in xylene or ethyl glycol acetate, generally corresponds to a flow time of 20 to 400 seconds.

The polyesters A and B polymers are water-insoluble, meltable Masses, which in the stated amounts without further additives are not in aqueous Phase are distributable.

It is therefore not desirable to incorporate larger proportions into them of polyether polyols, e.g. so-called poly waxes, to be modified, since such components make them hydrophilic, which results in lower water resistance of the coatings produced from the dispersions according to the invention.

The polyester A can be prepared by known processes (cf. Methods of Organic Chemistry (Houben-Weyl), Vol. 14/2, pp. 1 to 5, 21 to 23, 40 to 44, Georg Thieme Verlag Stuttgart, 1963, or C.R. Martens, Alkyd Resins, Reinhold Plastics Appl.

Series, Reinhold Publ. Comp. 1961, pp. 51 to 59), with alcohols, Carboxylic acids or their derivatives and optionally oils or fatty acids by melting or azeotrope esterification, preferably in an inert atmosphere, at temperatures of 140 to 2600C can be implemented. The reaction can e.g.

Weiden tracked by measuring the acid number and viscosity.

The polycondensation can take place in one or more stages, whereby in a known manner the boiling of a bles or the acidification means Dicarboxylic anhydride to the polyester can each be carried out as a separate step can.

Did at any of the stages in making the component A solvent is used, it must be used at the latest after the dispersion, e.g. by distillation.

Aqueous dispersions of the polyester resins A can be prepared by first producing polyester A and then using emulsifiers dispersed in the aqueous phase.

The polyesters A can be dispersed in the aqueous phase by you together with one or more emulsifiers and optionally others Additives in water-compatible or partially water-compatible solvents, such as acetone, ethyl alcohol, isopropanol, dissolves this solution into the aqueous phase stirred in and the organic solvent is then removed by evaporation.

On the other hand, preference is given to a method in which A is in the melt 80-1200C intimately mixed with the additives and then in this melt the aqueous phase is stirred in.

This process can usually be used in one for the manufacture of alkyd resins usual reactor can be made, high-speed mixing units or agitators are usually not required.

Of course, the melt can also be dispersed by adding the organic resin phase into the aqueous phase. It is also possible to to submit the emulsifiers in the aqueous phase and the emulsifier-free polyester resin Enter A into the mixture of emulsifiers and aqueous phase.

The emulsifiers required for dispersing the polyester A can be non-ionic (a) or ionic type (b) or mixed types, as e.g. "Methods of Organic Chemistry" (Houben-Weyl), Vol.

14/1, part 1, 4th edition, Georg Thieme Verlag, Stuttgart 1961, pp. 190-208, are described.

Preferred nonionic emulsifiers a) are compounds of the formula R¹-O-R²mH; R³-CO-O-R4nH where R1 and R3 are aliphatic, cycloaliphatic, araliphatic or aromatic group with 7-25 carbon atoms, 4 R2 and R C2H4O, C3H6 ° or C4H8O and m and n are integers from 3 to 100.

Other preferred nonionic emulsifiers a) are ethoxylated, if appropriate aliphatically substituted phenols. So is obtained according to the invention Polyester dispersions with particularly uniform particle sizes when used of ethoxylated p-n-nonylphenol. Other preferred emulsifiers a) are obtained through Ethoxylation of addition products of styrene and its derivatives with phenols, As described, for example, in DE-PS 1 121 814: Then styrene, oC-methylstyrene or vinyltoluene attached to phenol, cresols or xylenols and the resulting Ethoxylated reaction products.

Preferred nonionic emulsifiers a) have calculated HLB values of 10 to 20 and correspond to the formula R5- (OCH2-CH2) -OH p where -R5 is an alkyl radical with 12 to 20 carbon atoms or R6 is an alkyl radical with 4 to 20 carbon atoms or R7, R9 are a hydrogen atom, a methyl or phenyl radical, R8 is a methyl group or a hydrogen atom, p is a number from 10 to 40, preferably 15 to 25, q is a number from 1.0 to 3.0.

Regarding HLB values see Ullmanns Enzyklopädie der Technischen Chemie, 4th edition, Vol. 10, pp. 462-463, Verlag Chemie, Weinheim 1975.

Preferred ionic emulsifiers b) are C1218 alkyl sulfates and sulfonates.

Preferred mixed-type emulsifiers can be obtained, for example, by sulfation win the hydroxyl groups of the nonionic emulsifiers.

Oligomers and polymers can also be used as emulsifiers. This includes, for example, protective colloids such as casein.

Modified polyesters are also preferred as emulsifiers, which directly via ester bonds or via a connector with an or several polyalkylene oxides with 2-4 carbon atoms per alkylene radical are coupled, into consideration, this connector being made from a melamine resin, polyisocyanate or silicone can derive (cf. DE-OS 2 455 896, 2 503 388, 2 503 389, 2 528 212, 2 555 896, 2,556,621).

These emulsifiers contain over 5% by weight of polyalkylene oxide units.

These modified polyesters are subsequently also used as emulsifier resins called.

Preferred emulsifier resins consist of an optionally oil-modified one Polyester part (hydrophobic) and one, optionally by alkoxy groups with 1 to 4 carbon atoms terminated, polyalkylene oxide part (hydrophilic) with 6 to 100, preferably 10 to 70 alkylene oxide residues per polyalkylene oxide chain, the polyalkylene oxide part consists of several individual polyalkylene oxide chains and the alkylene group 2 to Contains 4, preferably 2, carbon atoms.

The emulsifier resins can contain 0.1 to 10% by weight, based on the emulsifier resin, Urethane groups included. According to a preferred embodiment, the one-sided blocked (e.g. etherified) polyalkylene oxides with approximately equimolar amounts of diisocyanate implemented so that polyalkylene oxides are formed, which have a free isocyanate group per molecule wear, which in turn for attachment to the polyester part of the emulsifier resin can serve.

Such emulsifier resins can be based on an OH-rich polyester Phthalic acid and / or tetrahydrophthalic acid and trimethylolpropane by reaction in the sense of DE-OS 2 556 621 and 2 528 212 with a polyethylene oxide-isocyanate precondensate are produced, the content of polyethylene oxide residues, based on emulsifier resin, between 10 and 20 wt .-% and the polyethylene oxide units have average molecular weights between 400 and 3000.

The average molecular weight for the manufacture of the emulsifier resins preferred polyester can be 400 to 4000 (vapor pressure osmometry in acetone certainly).

The polyalkylene oxides used can be homopolyethers, but also copolyethers be in block or statistical distribution; Homopolyethylene oxides are special preferred starting materials for the production of the emulsifier resins.

Come as a link between the polyester and polyalkylene oxide parts in principle all diisocyanates can be considered.

As a rule, those that are technically easily accessible are particularly preferred Polyisocyanates, e.g. 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers ("TDI"), 1,6-hexamethylene diisocyanate, perhydro-2,4'- and / or -4,4'-diphenylmethane diisocyanate and 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethylcyclohexane.

Emulsifier resins which are used lead to particularly homogeneous dispersions produced by making a poly ester with oil contents of 0-30 wt .- $ with an acid number of <5 and a hydroxyl number of 50-250 as produces hydrophobic part, this with the hydrophilic isocyanate components already mentioned Can react until complete conversion of the NCO groups, then with a Dicarboxylic anhydride to acid numbers from 15-35 to acidic and either by direct Adding an amine to the resin melt or by adding the resin melt to the Amine and optionally emulsifier a) containing water phase neutralized. In the latter In the process, the emulsifier resin falls together with the emulsifier a) as an aqueous solution or dispersion, as a so-called emulsifier concentrate.

The amount and type of emulsifier resin are best chosen so that the total content of polyalkylene oxide units in the non-volatile fraction of the invention Dispersion below 4% by weight, based on the sum of the calculated solids Components A and B, lies.

According to a preferred embodiment, the emulsifier resin contains im non-neutralized state carboxyl groups corresponding to an acid number of less than 50, preferably 15 to 35. The emulsifier resin can already before the combination be partially or completely neutralized with the aqueous phase. Preferred neutralizing agents are alkali hydroxides, ammonia, primary, secondary and tertiary Amines, such as ethylamine, di- and triethylamine, mono-, di- and triethanolamine, Dimethylethanolamine, methyldiethanolamine, dimethylaminomethylpropanol.

However, the neutralization can also be carried out when added to the aqueous phase take place.

For the preparation of the dispersions of the polyester A can in principle all of the emulsifiers described can be used individually and in a mixture.

Particularly good dispersions are obtained when using mixtures from an emulsifier resin and a low molecular weight ionic or preferably non-ionic emulsifier a), whereby the total amount of emulsifiers does not exceed 10 % By weight, based on the sum of components A and B, should be.

The best dispersions according to the invention are obtained when they are used an emulsifier combination consisting of 0.02 to 4 wt .-%, based on the invention Dispersion of the non-ionic emulsifiers described above with a calculated HLB value of 10 to 20 and 0.02 to 4% by weight, based on the sum of the components A, B, emulsifiers and aqueous phase, at least one polyether modified Polyester emulsifier resin, the 10 to 50, preferably 10 to 20 wt .-%, based on emulsifier resin, condensed-in polyalkylene glycol residues, preferably via urethane groups associated with the polyester emulsifier resin molecule.

The polyesters A can in the manner already described in aqueous Phase are dispersed.

One method has proven to be particularly favorable in terms of the workflow proven, in which the emulsifiers are placed in a stirred tank in the aqueous phase and then the polyester melt A is metered in with stirring. The temperatures in the mixing tank are 40-95, preferably 50-800C.

The neutralizing agent is expediently used in the emulsification in the melt stirred into the melt with some of the water and after homogenizing the rest of the water to adjust the dispersion to the desired solids content, usually between 30 and 50% by weight added.

In addition to water, the aqueous phase may contain neutralizing agents, the amount of which is to be measured in such a way that it leads to partial or complete neutralization at least the carboxyl groups which may still be present in the polyester resin A sufficient. The neutralizing agents are alkalis, ammonia or, preferably, the Above-mentioned amines can be used. Appropriately, in the emulsification in the Melt the amine with some of the water and stir it into the melt to homogenize the rest of the water Adjustment of the dispersion to the desired solids content, which is generally between 40 and 60%.

The polymers B are preferred by emulsion polymerization manufactured. The relevant techniques are for example in methods of organic Chemie, (Houben-Weyl), Vol. 14/1, 4th edition, pp. 133-560, Georg Thieme Verlag, Stuttgart Described in 1961.

TLC, B-ethylenically monounsaturated compounds preferred for the preparation of polymers B are (meth) acrylic acid monoesters of C1-C10 monoalcohols and C2-C10 dialcohols, (meth) acrylic acid, (meth) acrylonitrile, (meth) Acrylic acid amide, N-alkoxymethyl (meth) acrylic acid amide, fumaric acid and maleic acid esters of C1-C10 monoalcohols and C2-C10 dialcohols and styrenes of the formula where R10, R11, R12 and R13 each represent a hydrogen atom or a Ct-C4-alkyl radical.

Particularly preferred monomers are C1-C4-alkyl acrylates, methacrylic acid, Hydroxyethyl methacrylate, hydroxypropyl methacrylate and styrene and their mixtures.

The polymer B preferably contains reactive groups such as OH, COOH, which are introduced by the corresponding monomers. The ratio of Monomer to water phase is usually chosen so that the proportion of polymer B between 30 and 70, preferably 40 and 55% by weight (based on the sum of B + Water).

Particularly resistant coatings are obtained by using polymer compositions selects the following structure: alkyl acrylate of C1-C4 monoalcohol 35-65% by weight styrene 25-55% by weight methacrylic acid 1-10% by weight hydroxypropyl methacrylate 1-15% by weight wherein the percentages relate to the solids content of polymer B.

The dispersions of the polymer B are according to the invention with the Dispersions of polyester A at temperatures between 40 and 950 ° C., preferably 50 to 800C, mixed. For this purpose, the dispersion of the polymer B should have pH values> 6.5, preferably 7.0-8.5. If dispersion B is too acidic, neutralize one of the amines listed above.

The dispersions of A and B are preferably mixed immediately after the preparation of the polyester dispersion A. It is therefore expedient to first set the polymer dispersion B and indicates during or immediately afterwards the dispersion of X component A to the dispersion of B. It is in principle any order of combining polyester A, water phase, emulsifier and dispersion B possible, the addition of each of these ingredients in several steps and can be carried out in different sequences. The following procedures are preferred: a) The polyester melt A is placed in a template of water phase, emulsifiers, stirred at 50 to 80 ° C. and added dispersion B to the dispersion formed and mixes at 50 to 800C.

b) The polyester melt A is combined at 80 to 1200C with the Emulsifiers and then gives first the water phase and then the dispersion from B at 50 to 800C to; then it is mixed at 50-80 ° C.

Dispersions of hydrolysis-labile and low molecular weight polyesters A are used better mixed at lower temperatures, e.g. 5 ° C, while dispersions are higher molecular weight Polyester A can often be mixed better at higher temperatures, e.g. 950C.

The water content of the dispersions according to the invention is generally at 30 to 75% by weight, based on the dispersion.

The systems according to the invention are particularly suitable for production of lacquers, especially stoving lacquers. The dispersions according to the invention can one water-thinnable, crosslinking amino resins, e.g. melamine resins in quantities from 10 to 50, preferably 10 to 30 wt .-%, based on the mixture of binder and melamine resin. These mixtures can be used directly after setting the necessary Viscosity and, if appropriate, after the addition of catalysts and auxiliaries Coatings are processed and thermally cured.

The dispersions according to the invention can optionally also for areas of application other than the stoving lacquer sector are used: in manufacturing non-planar structures such as moldings, gels and the like.

Small amounts of customary auxiliaries and additives can be added to the dispersions add, e.g. antifoam agents, anti-settling agents, antifreeze agents, as well as viscosity-influencing agents Additives, leveling agents, crosslinking catalysts; however, here is in either case to check compatibility.

Sometimes it is for reasons of better processability and pigment absorption Favorable, the dispersion in the paint production to certain pH values, e.g. 7.5 bring up to 8.5. Usually the ones already used for neutralization are used for this purpose Neutralizing agent. Small additions of water-miscible solvents such as ethanol or butyl glycol, can also be added, but most of the time it is not necessary. Leave the paints produced with the dispersions according to the invention using the usual application technique, e.g. by dipping, spraying, pouring apply the materials to be painted.

The viscosity required for this is usually established by adding of water.

The applied paint films can be used at room temperature and at higher temperatures Temperature, e.g. between 60 and 3600C. The high temperature range is preferably used for low-oil and oil-free polyesters.

The parts given in the following examples are parts by weight, Percentages mean percentages by weight.

Examples Emulsifier I Ethylene oxide grafted onto nonylphenol (molar ratio 1:20) with the following properties: Cloud point (1% in water): approx. 1000C surface tension (0.1 g / l water): 44.0 dynes / cm wetting effect (DIN 53 901): approx. 60 sec at 600C Fp .: approx. 300C HLB value: 16 emulsifier resin II In a 2 1 mixing beaker apparatus, which is equipped with Internal thermometer, stirrer, dropping funnel and gas inlet tube are provided 400 g of a polyethylene oxide alcohol of molecular weight started on n-butanol 2000 dehydrated for 30 minutes at 1200C while applying a vacuum (15 Torr). In the First, 2 ml of benzoyl chloride are stirred in the melt, which has been cooled to 1000C; thereafter 33.6 g of hexamethylene diisocyanate are added in one go.

After a reaction time of 60 minutes, the isocyanate content of the mixture increases certainly. The NCO content of the mixture is then 1.8 to 1.9% by weight NCO (calc .: 1.94%).

After the melt has cooled, those for further reactions are obtained suitable hydrophilic isocyanate component as a waxy crystalline substance.

134 g trimethylol propane and 130.7 g tetrahydrophthalic anhydride are esterified at 2200C under a nitrogen atmosphere to an acid number of 4. The viscosity the precursor obtained corresponds to a flow time (measured as a 60% solution in dimethylformamide according to DIN 53 211, DIN cup 4) for 170 seconds.

500 g of this preliminary stage are dehydrated in vacuo and then reacted with 88.2 g of the hydrophilic isocyanate component at 100 to 1050C, until no more free isocyanate groups can be detected.

580 g of this product are mixed with 39 g of tetrahydrophthalic anhydride converted at 1200C to a poly half ester with an acid number of approx. 27.

To 610 g of this stage are carefully added with stirring at 95 to 1000C 26.1 g of dimethylethanolamine.

The resin solidifies as it cools to form a viscoplastic, meltable one Dimensions.

Polyester A 84.6 parts of castor oil, 3.56 parts of trimethylolpropane and 11.84 parts of phthalic anhydride are used at 2500C under dehydration conditions cooked to a product with an acid number of 25-35.

137.4 parts of this precursor, 90.2 parts trimethylolpropane, 11.8 parts Neopentyl glycol, 11.9 parts benzoic acid and 120.4 parts tetrahydrophthalic anhydride are after a heating phase in a suitable reactor while passing nitrogen through Esterified at approx. 1950C until the acid number of the product is 15-16. The final viscosity of the resin, measured in xylene according to DIN 53 211, corresponds to 50% a flow time of 120 seconds. The oil content is approx. 35%.

Polymer resin B 38 parts of styrene, 52 parts of butyl acrylate, 5 parts of hydroxypropyl methacrylate and 5 parts of methacrylic acid are added after pre-emulsification of part of the monomers at 80 ° C. in the presence of 150 parts of water, 0.2 part Polymerized alkyl sulfonate and 0.53 parts of K2S208 in emulsion. You get one Resin dispersion with approx. 40% solids.

Example (according to the invention) a) 520.8 parts of polyester A, 22.4 parts Emulsifier resin II, 16.8 parts of emulsifier I are under a nitrogen atmosphere at 1200C Stirred in the melt, cooled to 800C and a solution at 80-600C with stirring of 11.54 parts of dimethylethanolamine in 795.16 parts of water within 10 minutes admitted. The mixture is stirred for a further 10 minutes at 60-700C and then within one half an hour at 70-600C 2100 parts of the neutralized with dimethylethanolamine Add dispersion of B, stir for 10 minutes at 60-650C and cool. After filtering a stable dispersion A / B is obtained.

b) From 500 parts of TiO2 pigment, 375 parts of crosslinking melamine resin, 15 parts of 10% dimethylethanolamine and 100 parts of water became a grist formulation produced, which was ground on a pearl mill for 15 minutes.

This was with a mixture of 525 parts of the dispersion A / B and 50 parts of 20% dimethylethanolamine and after a maturing period with Water diluted from spray viscosity.

Comparative experiment a) (polymer B missing) In the same way as in Example b) has been described the grist formulation with 525 Divide the polyester dispersion A and, after a maturing time, with water diluted from spray viscosity.

Comparative experiment b.) (Mixing at room temperature) 93 parts of polyester A, 4 parts of emulsifier resin II and 3 parts of emulsifier I were at 1200C under a nitrogen atmosphere mixed in the melt, cooled to 800C and a mixture of water with stirring and as much dimethylethanolamine was added that neutralized the carboxyl groups by 80% of the polyester is sufficient. The amount of water is such that a dispersion with 40% resin content results. After a further stirring time at 60-650C of approx. 30 Minutes, a finely divided dispersion is obtained, which is cooled to room temperature became.

This dispersion was mixed with the polymer dispersion at room temperature B in the ratio 4 (polyester): 6 (polymer) mixed.

This material is used in the same way and in equal proportions as described in example b), lacquered with the grist formulation and after a Maturing time diluted with water from spray viscosity.

Comparative experiment c> (polyester A missing) To improve the pigment dispersibility the millbase formulation of example b) was additionally with 15.3 parts of a Dispersing aid equipped. 301 parts of this grist formulation were used lacquered with 525 parts of the polymer dispersion B and, after a maturing time, with Water diluted to spray viscosity.

Production of coatings The coatings of the example and the comparative tests a-c were sprayed onto non-phosphated iron sheets (Bonder? 405) and 30 Baked in minutes at 140 ° C. The panels were then subjected to the secondary salt test according to DIN 53 167. The results are summarized in the following table. Tabel Example comparative comparative comparative test a test b test c adhesion good good bad bad Test duration (days) 19 2 5 5 rusting under 12 mm 15 mm

Claims (9)

Claims 1. Process for the production of aqueous dispersions, their non-volatile fractions essentially consist of A) 80-20% by weight of at least one Polyester, B) 20-80 wt .- $ of at least one polymer α, ß-ethylenic monounsaturated compounds and C) consist of 0.5 to 10% by weight of emulsifiers, where the percentages relate to the sum of components A and B, characterized in that one polyester A and polymer B, each at most may contain up to 1 wt .-% condensed polyalkylene glycol residues, each dispersed separately in the aqueous phase, the dispersions are mixed in the heat so that that the mixing temperature is 40-950C, and the resulting mixture 5 to 180 minutes stirred at 40-950C. 2. The method according to claim 1, characterized in that the mixing and stirring temperature is 50-800C. 3. Process according to Claims 1 and 2, characterized in that the mixture is subsequently stirred for 10 to 30 minutes. 4. The method according to claims 1-3, characterized in that as Emulsifier C is a non-ionic emulsifier with a calculated HLB value of 10 used up to 20. 5. Process according to Claims 1-4, characterized in that one as emulsifier C, a combination of 0.02 to 4% by weight, based on the invention Dispersion, a non-ionic emulsifier with a calculated HLB value of 10 to 20 and 0.02 to 4% by weight, based on the dispersion according to the invention, at least of a polyether-modified polyester emulsifier resin which condensed in 10 to 50% by weight Polyalkylene glycol residues. used. 6. Dispersions obtainable by the process according to Claims 1-5. 7. Dispersions according to claim 6 having an average particle diameter the disperse phase from 50 to 3000 nm. 8. Use of the dispersions according to Claims 6 and 7 for the preparation of paints. 9. Use according to claim 8 for the production of stoving enamels.