DE2903022A1 - Finely-divided aq. polyester dispersion prepn. - by dispersing polyester with nonionic emulsifier and polyether-modified polyester emulsifier in neutraliser-contg. aq. phase - Google Patents

Abstract

Finely-divided aq. polyester dispersions are prepd. by dispersing 25-60 wt.% polyester, (I), opt. contg. 5 wt.% condensed-in polyalkylene glycol pgs. in the presence of 0.02-4 wt.% of >=1 nonionic emulsifier (IIa) and of 0.02-4 wt.% of >=1 polyether-modified polyester emulsifier resin (IIb), in 32-75 wt.% aq. phase, (III), contg. 30-150% of the alkali-, NH3- or amine proportion needed for a complete neutralisation of the COOH gps. of polyesters (I) and (II). Dispersion temps. are such that mixing temp. is 50 degrees C. The dispersion obtd. is further stirred 15 min. to 5 hrs. at 50-90 degrees C, until the desired average particle size is achieved. (IIa) has HLB-value 10-20 and formula R-(OCH2CH2)n-OH (where R is 12-20C alkyl or p-R1-C6 H2(R3R4)-; R1 is 4-20C alkyl or Ph-CR2Me-; R2 is H, Me or Ph; R3 is Me, Ph or H; R4 is Me or H and n is 10 to 40 esp. 15 to 25). (IIb) contains 10-50 (esp. 10-20) wt.% condensed-in polyalkylene glycol gps. bonded to the polyester-emulsifier resin mol. esp. via urethane gps. The dispersions are also claimed. The dispersions are used in the prepn. of lacquers, esp. stoving lacquers, and opt. in the prodn. of shaped articles and gels.

Description

one-part aqueous polyester dispersions, method too

Their Manufacture and Use The present invention relates to finely divided aqueous polyester dispersions, which are excellent for production high-gloss coatings with excellent mechanical properties are suitable, a process for the preparation of these dispersions and their use for the preparation of paints.

The dispersions are referred to as "finely divided" when their mean particle diameter, measured with the help of quasi-elastic light scattering between 300 and 100 nm, preferably between 200 and 100 nm, is under "polyesters" both oil-free polyesters and alkyd resins are understood below, cf. below: definition of polyester I.

In the following, the term “aqueous dispersions” refers to heterogeneous systems understood, which are opaque and in which the organic resin phase in water is distributed.

In the following, the term "aqueous dispersions" is therefore included not those polyester solutions that are in aqueous Phase form transparent solutions; such resins usually have acid numbers 540, are pre-dissolved in ml of water-miscible organic solvents and after the neutralization with water to form homogeneous, transparent solutions.

Speak in favor of the increasing use of aqueous polyester dispersions 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 (cf.

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

Paints based on aqueous polyester dispersions are said to be storage-stable and lead to waterproof coatings that are high even with higher pigmentation Have gloss and good mechanical properties an ideal combination of these Properties is so far unknown; so have coatings made from dispersions according to DE-OS 25 54 330 and DE-OS 26 40 127, for example, do not have a sufficient gloss.

Surprisingly, it has now been found that aqueous polyester dispersions can be used with the desired combination good properties, though the polyester to be dispersed in the presence of a) at least one nonionic Emulsifier and b) at least one polyether-modified polyester emulsifier resin dispersed in water phase containing neutralizing agent at higher temperature and the resulting dispersion is subsequently stirred under defined temperature conditions.

The invention relates to a process for the preparation of finely divided aqueous polyester dispersions, characterized in that I. 25 to 60% by weight of polyester, which may contain at most up to 5% by weight of condensed polyalkylene glycol residues, in the presence of II , 02 to 4 wt .-% of at least one non-ionic emulsifier with a calculated HLB value of 10 to 2G, preferably corresponding to the formula R- (OCH2-CH2) n-OH wherein R is an alkyl radical with 12 to 20 carbon atoms or R1 is an alkyl radical with 4 to 20 carbon atoms or R2 is a hydrogen atom, a methyl or phenyl radical, R3 is a methyl group, a phenyl radical or a hydrogen atom, R4 is a methyl group or a hydrogen atom, n is a number from 10 to 40, preferably 15 to 25, and II. B) 0.02 up to 4% by weight of at least one polyether-modified polyester emulsifier resin which contains more than 5 to 50, preferably more than 5 to 20% by weight, based on the emulsifier resin, of condensed polyethylene glycol residues, preferably via urethane groups with the polyester emulsifier resin Molecule connected, contains, in III from 32 to 75% by weight aqueous phase containing 30 to 150% of the amount of alkali, ammonia or amine sufficient for complete neutralization of the carboxyl groups of the polyester I, dispersed at temperatures such that the Mixing temperature is above 50 ° C., and the resulting dispersion is stirred for 15 minutes to 5 hours at 50 to 90 ° C. until the desired mean particle size has formed.

The above percentages by weight relate - unless otherwise specified - on the sum of components I, II and III; for HLB value see Utlmanns Encyclopadie der Technischen Chemie, 4th ed., Vol. 10, pp.

462 - 463, Verlag Chemie, Weinheim 1975.

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 finely divided aqueous polyester dispersions according to the invention are characterized by excellent stability and can be used to produce coatings with excellent Adhesion, hardness, elasticity and high gloss can be processed.

Polyesters are understood to be known through polycondensation Process from alcohols and carboxylic acids produced polycondensates of the type such as they e.g. in Römpp's Chemielexikon, Vol. 1, p. 202, Frankh'sche Verlagsbuchhandlung, Stuttgart, 1966, defined or porridge D.li.

Solomon, The Chemistry of Organic Filmformers, 5 75-101, John Wiley & Sons Inc., New York, 1 967 for the synthesis of polyesters I preferred alcohols are aliphatic, cycloaliphatic and / or aromatic. Alcohols with 1 to 6, preferably 2 to 4, attached to non-aromatic carbon atoms OH groups and 1 to 24 C atoms per molecule, e.g. glycols such as ethylene glycol, propylene glycol, Butanediols, neopentyl glycol, trimethylpentanediol-1,3, hexanediols; Ethereal alcohols such as di- and triethylene glycols; ethoxylated bisphenols with 2 alkylene oxide residues per Molecule; perhydrogenated bisphenols; also trimethylolethane, trimethylolpropane, trimethylolhexane, i-i, zerlr, pentacrytritol, dipentaerythritol, dimethylolcycloexn, mannitol and sorbitol; monovalent, chain-breaking alcohols such as methanol, propanol, butanol, cyclohexanol, 2-ethylhexanol and benzyl alcohol Particularly preferred alcohols are neopentyl glycol, trimethylol propane, Dimethylolcyclohexane and Perhydrobisphenol The polyesters I can contain up to 15% by weight, based on polyester I, containing monohydric alcohol residues condensed in For the synthesis of the polyester I 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 hexahydrophthalic anhydride, trimellitic anhydride, Pyromellitic anhydride, maleic anhydride, fumaric acid, adipic acid, glutaric acid and succinic anhydride, azelaic acid, endomethylenetetrahydrophthalic acid, further halogenated acids such as chlorophthalic acids and hexachloro-endcethylene tetrahydrophthalic acid.

Combinations of 20 mol% (based on the dicarboxylic acids used) Phthalic acid and 80 mol% tetrahydrophthalic acid deserve special mention as they lead to both good storage stabilities and paints that run well the Polyesters I can be built up solely from polycarboxylic acids and polyalcohols But it is also possible to modify them by condensation of monocarboxylic acids.

Monocarboxylic acids preferred for the preparation of the polyester I 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 Products obtained by conjugation or isomerization; preferred saturated fatty acids are for example coconut fatty acids, g-ethylhexanoic acid, isononanoic acid and linear C16-C18 monocarboxylic acids.

Oil-modified polyesters (alkyd resins) lead within the scope of the invention for coating agents with particularly good body. Particularly preferred oil-modified ones Polyesters I are those with an oil content of 20 to 50, preferably 25 to 40% by weight, calculated as triglyceride and based on polyester I.

Polyester 1 for polyester dispersions that are used for the production of oven-drying Serving paints, usually come with oil contents of 0 to 45 wt .-% from high contents aromatic components of the polyester I give the paint coating Particular hardness, high content of aliphatic components of the polyester I give i1iin good elasticity.

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

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

It is possible up to 25% of the ester bonds of the polyester I through To replace urethane connections, but the polyester I is preferably urethane group- free.

The molecular weight of the polyester I determined as the number average is 800 to 10,000, preferably 1500 to 3000 (up to molecular weights of 5000 vapor pressure cosmometric determined in dioxane and acetone, the lower value if the values differ is considered correct; membrane osmometric for molecular weights above 5000 determined in acetone).

The selection of the type and amount of each to be condensed to polyester I. Raw materials depend on the molecular weight and the area of application of the polyester dispersion according to the invention The relationships between molecular weight and amount of raw material are atU. Holfort, Farbe und Lack 68 (1962), pp. 513 to 517, P. 598 to 607 described in detail, The viscosity of the polyester I, measured according to DIN 53 211 (DIN cup 4) as a 50% strength by weight solution in xylene or Ethyl glycol acetate, usually corresponds to a flow time of 20 to 400 seconds.

The polyesters I are water-insoluble, meltable masses, which in the stated amounts cannot be distributed in the aqueous phase without further additives are. It is therefore not desirable to incorporate the polyester I into the weight to modify falling proportions of polyalkylene oxides, e.g. so-called polywaxes, because such constituents make the polyester I hydrophilic, which results in less Water resistance of those produced from the polyester dispersions according to the invention Coatings.

The polyesters I can be prepared by known processes (cf. Methods of Organic Chemistry (Houben-Weyl), Georg Thieme Verlag Stuttgart, 1963, Vol. 14/2, pp. 1 to 5, 21 to 23, 40 to 44, or C.R Martens, Alkyd Resins, Reinhold Plastics Appl. Series, Reinhold Publ. Comp. 1961, pp. 51 to 59), whereby Alcohols, carboxylic acids or their derivatives and possibly oils by melting or azeotrope esterification, preferably in an inert atmosphere, at temperatures of 140 to 2600C can be implemented. The reaction can e.g. by measuring the acid number and viscosity can be monitored.

The polycondensation can take place in one or more stages, wobe-i in a known way the boiling of an oil or the acidification by means of Dicarboxylic acid anhydride to the poly half ester in each case as separate Stage can be carried out. Preferred nonionic emulsifiers II a) are ethoxylated aliphatically substituted aromatics. Thus, according to the invention, one obtains Polyester dispersions with particularly uniform particle sizes when used of ethoxylated p-n-nonylphenol. Other preferred emulsifiers II a) are obtained by ethoxylation of addition products of styrene and its derivatives Phenols, such as e.g.

in DE-PS 1 121 814 is described. Then styrene, i -methylstyrene or vinyltoluene attached to phenol, cresols or xylenols and the resulting Ethoxylated reaction products. In emulsifier mixtures, n means the mean value of polyethylene oxide units.

Preferred emulsifier resins II b) consist of an optionally oil-modified polyester part (hydrophobic) and one, optionally with 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 II b) can contain 0.1 to 10% by weight, based on the emulsifier resin II b), contain urethane groups.

According to a preferred embodiment, the unilaterally blocked (e.g. etherified) polyalkylene oxides with approximately equimolar amounts Diisocyanate reacted, so that polyalkylene oxides are formed, which are free per molecule Carry isocyanate group, which in turn for attachment to the polyester part of II b) can serve.

The average molecular weight for the manufacture of the emulsifier resins II b) preferred polyester can be 400 to 4000 (vapor pressure osmometric in Acetone determined).

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 preparation of the emulsifier resins II b).

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

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

The amount and type of emulsifier resin II b) are best selected so that that the total content of polyalkylene oxide units in the non-volatile portion of the invention Polyester dispersion is below 4% by weight, based on the sum of components I, IIa and IIb.

In a preferred embodiment, the emulsifier resin contains II b) in the 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 with the aqueous phase III can be partially or completely neutralized. 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. The neutralization but can also take place when added to the aqueous phase.

Processes for the preparation of the emulsifier resins II b) are known; see. DE-OS 25 28 212, 25 56 621.

Neutralizing agents are part of the aqueous phase III preferably alkalis or in particular the above amines, with dimethylethanolamine is particularly preferred.

Emulsifier resins II b, which lead to particularly smooth dispersions is produced by using a polyester with an oil content of 0-30 wt an acid number of 5 and a hydroxyl number of 50-250 as the hydrophobic part, these with the already mentioned hydrophilic isocyanate components up to the complete Reaction of the NCO groups, then with a dicarboxylic acid anhydride on Acid numbers of 15-35 and either by direct addition of an amine in the resin melt or by adding the resin melt to the amine and optionally Component IIa containing water phase neutralized. In the latter case falls the emulsifier resin lIb together with the emulsifier IIa as an aqueous solution or dispersion, as so-called emulsifier concentrate.

The polyesters I can be dispersed in the aqueous phase by the polyester I together with the substances II a) and II b) in the melt 80 to 120 ° C. intimately stirred and then this melt the aqueous phase III clogs. This process can usually be carried out in a conventional reactor for production made of polyesters. High-speed mixing units or agitators are usually not required. Melt dispersion can of course be used can also be carried out by adding the organic resin phase I and II to the aqueous phase III.

One method has proven to be particularly favorable in terms of the workflow proven in which in the aqueous phase III the substances II a) and II b) in one Submitted stirred kettle and then metered in the polyester melt I with stirring will. If necessary, IIb is presented in the neutralized state.

Regardless of the order and type of addition of the components According to the invention, the dispersion formed must be for 15 minutes to 5 hours 50 to 900C. Highly condensed, hydrolysis-resistant polyester I. within this framework, longer stirring times and higher temperatures, while more unstable to hydrolysis Polyester I get by with lower temperatures and shorter stirring times.

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 g by weight added.

The viscosity of the resulting dispersion is convenient by the amount of the added neutralizing agent can be influenced. For example, does the polyester have a Acid number t? 8, degrees of neutralization> 90% result in a residual body of approx. 40% by weight already to highly viscous dispersions. Lower degrees of neutralization can be used under These circumstances appear to be indicated1 since they have good flowability for the same solid body ensure the dispersion. If the acid number of the polyester is lower, this is the case Viscosity dependence less pronounced. It is of course possible that Desired degree of neutralization and thus the desired viscosity in several to adjust.

The polyester dispersions according to the invention can be used in the production or afterwards with other polymers, e.g.

Polyacrylates, polyurethanes and hard resins, e.g.

Colophony or xylene-formaldehyde condensates' that is, unmodified and modified polymers, as described by H. Kittel, Textbook of Lacquers and Coatings, Vol. I, Part 1, Verlag W.A. Colomb, Stuttgart-Berlin, 1971, pp. 122 to 445 are to be combined.

The systems according to the invention are particularly suitable for production of paints, especially stoving enamels, particularly castor oil as oils and soybean oil and the corresponding, optionally dehydrated fatty acids have proven successful to have. The dispersions according to the invention can be water-thinnable, crosslinking Amino resins, e.g. melamine resins in amounts of 10 to 50, preferably 10 to Add 30% by weight, based on the mixture of polyester I and melamine resin. These Mixtures can be used directly after setting the necessary viscosity and, if necessary After the addition of catalysts and auxiliaries, processed into coatings and thermally to be 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. protective colloids, anti-fouling agents, anti-settling agents, antifreeze agents, as well as viscosity-influencing additives, leveling agents, crosslinking catalysts; however, the compatibility must be checked in each case.

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 provided one usually by adding 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 following examples explain the invention; the specified Parts are parts by weight, percentages are percentages by weight.

Examples Production of polyester I resin A 1446 parts dehydrated Castor oil, 1,201.8 parts of trimethylolpropane, 149 parts of neopentyl glycol, 150 parts Benzoic acid, 1521 parts of tetrahydrophthalic anhydride and 205.5 parts of phthalic anhydride were passed through with nitrogen after a heating phase at 1800C for so long esterified until a polyester with an acid number of approx.

17 and a viscosity corresponding to a flow time of approx. 122 Seconds (50% in xylene, measured according to DIN 53 211, DIN cup 4).

Resin B 1750.3 parts of neopentyl glycol, 375.9 parts of trimethylolpropane, 1673.7 parts of azelaic acid and 1410 parts of isophthalic acid were passed through esterified by nitrogen after a heating phase at 2300C to an acid number <3. 116.9 parts of maleic anhydride are added to 4065.9 parts of this precursor and at 150 to 160 ° C. up to an acid number of 17 and a viscosity accordingly a start-up time (50% in ethyl glycol acetate, measured according to DIN 53 211, DIN cup 4) implemented in approx. 78 seconds.

Resin C 373.9 parts ethylene glycol, 1065.3 parts neopentyl glycol, 243.2 Parts of trimethylolpropane, 474.4 parts of 1,6-hexanediol, 667.3 parts of isophthalic acid, 2082.4 parts of phthalic anhydride and 293.5 parts of adipic acid are passed through of nitrogen after a heating phase at 240 ° C up to an acid number of approx. 3 esterified. 138.9 parts of maleic anhydride are added to 4188.9 parts of this precursor and sets at 140 to 160C up to an acid number of approx. 23 and a viscosity corresponding to an outflow time (60% in ethyl glycol acetate according to DIN 53 211, DIN cup 4) from about -200 seconds.

Resin D 1004.2 parts of a mixture of linear saturated C16-C18 Fatty acids, 426.9 parts isononanoic acid, 1673.1 parts trimethylolpropane, 83.8 parts Neopentyl glycol, 1995 parts of tetrahydrophthalic anhydride were passed under of nitrogen after a heating phase at 200 ° C up to an acid number of approx. 16 and a viscosity corresponding to a flow time (50% in xylene, measured esterified according to DIN 53 211, DIN cup 4) for 48.5 seconds.

Emulsifier II a) 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 dyn / cm wetting effect (DIN 53 90 approx. 60 sec at 600C Fp .: approx 300C HLB value: 16 Emulsifier II b) In a 2 liter mixer apparatus which are equipped with an internal thermometer, stirrer, dropping funnel and gas inlet tube is 400 g of a polyethylene oxide alcohol started on n-butanol of molecular weight 2000 dehydrated for 30 minutes at 120 ° C. while applying a vacuum (15 torr). In dje First, 2 ml of berizol chloride are stirred in the melt cooled to 1000C; thereafter 33.6 g of hexame + gen diisocyanate are added in one pour.

After a reaction time of 60 minutes, the isocyanate content of the mixture increases certainly. The NCO number of the mixture is then 1.8 to 1.9% NCO (calc .: 1.94 %) After the melt has cooled, the hydrophilic one which is suitable for further reactions is obtained Isocyanate component as a waxy crystalline substance.

134 q trimethylolpropane and 130.7 g tetrahydrophthalic anhydride are esterified at 220 ° C under a nitrogen atmosphere to ur acid number 4 The viscosity the precursor obtained corresponded to an outflow 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 tetrahadrophthalic anhydride reacted at 1200C to a poly half radical with an acid number of approx. 27.

To 610 g of this stage are carefully added from 95 to 1000 ° C. while stirring 26.1 g of dimethylethanolamine.

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

Emulsifier II a) and emulsifier resin II b) are in a weight ratio 3: 4 combined with one another and to an approx. 45% aqueous slightly opaque solution good flowability and handleability. This solution is given below referred to as emulsifier concentrate.

Example 1 485 parts of the emulsifier concentrate are used in a stirred apparatus (45 via), 3551 parts of condensation water and 59.4 parts of dimethylethanolamine at 50 ° C., Nitrogen passed over and then 2900 parts of the approx. 1100C hot melt of the resin A entered while stirring and avoiding the entry of air. Shortly after finishing After the addition of resin, a mean particle size of 209 nm was found in a sample. The dispersion was then stirred for 1 hour at 60 ° C. and over the course of 2 Evenly cooled to 40 ° C. for hours while stirring. After that the mean was Particle diameter 152 nm. At 40 ° C., by carefully adding dimethylethanolamine and water have a degree of neutralization of approx. 88% and a solids content of approx. 42% set.

From 210 parts of titanium dioxide pigment, 95 parts of the dispersion, 35 parts of a melamine resin 6.3 parts of 10% dimethylethanolamine and 50 parts of water a grist was prepared with 404 parts of dispersion, 78 parts of melamine resin and 40 parts of water was dissolved. After 1 day of maturation it was down to 19 seconds Outlet viscosity (DIN 53 211, DIN cup 4) diluted with water, on glass plates and metal sheets and baked for 30 minutes at 120 ° C. The paint film obtained had the following properties: Layer thickness: 38, u Gloss (Gardner 200): 82 Erichsen value: 7.4 Pendulum hardness: 112 sec Pencil hardness: 2 H Cross cut: 0-1 example 2,571.4 parts of emulsifier concentrate 46.1%, 3370.3 parts of water and 84.9 parts of NN-dimethylethanolamine were placed at 430C and 3499.8 parts of the hot melt at 1200C with stirring of the resin B entered with stirring and a nitrogen atmosphere. The dispersion possessed a non-uniform particle image with an average particle diameter of about 400 nm. It was stirred for 2 1/2 hours at 80 ° C. and thereby reached a medium temperature Particle size of 188 nm.

The dispersion obtained had a solids content of approx. 41%.

From 30 parts of hexamethoxymethylmelamine, 200 parts of titanium dioxide pigment, 50 parts of water and 6 parts of 10% dimethylethanolamine was prepared according to conventional techniques a pigment grind produced. To this were added 425 parts of the dispersion and 5.8 parts leveling agent. After briefly rubbing again and a maturing period of 1 day was sprayed onto metal sheets, flashed off and baked at 140 ° C. for 30 minutes. The paints had the following properties: Gloss (Gardner 600): 85 gloss (Gardner 200): 77 Pencil hardness: HB Elasticity: good Cross-cut according to DIN 53 151: 0 example 3,546.4 parts of Eulgator concentrate (46.1% strength), 3192.3 parts of water and 111.8 parts Dimethylethanolamine were initially introduced at 410C and 3346.7 parts of the 1200C hot melt of resin C entered with stirring and a nitrogen atmosphere. It was held at 60 ° C. for 1/2 hour and diluted with water to a solids content of 31 t. The dispersion had an average particle diameter of 164 nm.

256 parts of the pigment pulp from Example 2 were added to 566 parts the dispersion and 5.8 parts of leveling agent were added. After a short renewed Rubbing and a maturing time of 1 day was sprayed onto a metal sheet and flashed off and baked for 30 minutes at 1400C.

The paint showed the following properties: Gloss (Gardner 600): 88 gloss (Gardner 200): 77 Pencil hardness: 2 H Elasticity: good Cross-cut according to DIN 53 151: 0 Example 4 553.7 parts of emulsifier concentrate (46.1% via), 755 parts of dimethylethanolamine and 3272.6 parts of water were initially charged at 420C and with 3391.2 parts of 2 / 1200C hot melt of the resin D entered with stirring and a nitrogen atmosphere. It was held at 60 ° C. for 30 minutes and then gave another 1823.3 Allocate water. The dispersion had an average particle diameter of 265 nm and a solids content of approx. 42%.

240 parts of titanium dioxide pigment, 96.4 parts of dispersion, 35 parts of melamine resin, 6.3 parts of 10% dimethylethanolamine, 40 parts of water were used to form a millbase formulation processed and lacquered with 410 parts of dispersion and 38 parts of melamine resin. After a ripening time of 1 day, the viscosity was increased to 21 seconds with water (DIN 53 211, DIN cup 4) thinned, sprayed onto glass plates or metal sheets, vented and baked for 30 minutes at 1300C. A high-gloss varnish was obtained good filling power and good mechanical and chemical resistance.

Claims (9)

Claims 1) A process for preparing finely divided aqueous polyester dispersions, characterized in that I. 25 to 50 wt .-% polyester, which may contain up to 5 wt .-% condensed polyalkylene glycol residues, in the presence of II.a) 0.02 to 4% by weight of at least one non-ionic emulsifier with a calculated HIBQ value of 10 to 20, preferably corresponding to the formula A- (OCH2-CH2) n-OH in which R is an alkyl radical with 12 to 20 carbon atoms or R1 is an alkyl radical with 4 to 20 carbon atoms or R2 is a hydrogen atom, a methyl or phenyl radical, R3 is a methyl group, a phenyl radical or a hydrogen atom, R4 is a methyl group or a hydrogen atom and n is a number from 10 to 40, preferably 15 to 25, and II.b) 0; 02 to 4% by weight of at least one polyether-modified polyester emulsifier resin which contains 10 to 50, preferably 10 to 20% by weight, based on the emulsifier resin, of condensed polyalkylene glycol residues, preferably connected to the polyester emulsifier resin molecule via urethane groups, in III. 32 to 75% by weight of the aqueous phase, which contains 30 to 150% of the amount of alkali, ammonia or amine sufficient for complete neutralization of the carboxyl groups of the polyesters I and II b), is dispersed at temperatures such that the mixing temperature is above 50.degree , and the resulting dispersion is stirred for 15 minutes to 5 hours at 50 to 90 ° C. until the desired mean particle size has formed. 2) Method according to claim 1, characterized in that one polyester I together with emulsifier II a) and polyester emulsifier resin II b) in the melt stirred intimately at 80 to 120 c and then this melt the aqueous phase III adds. 3) Method according to claim 1, characterized in that one emulsifier II a) and polyester emulsifier resin II b) presented in aqueous phase III and the polyester melt I adds while stirring. 4> Process according to Claims 1 to 3, characterized in that the entire amount of the neutralizing agent with some of the water in the Stir in melt of components I, II a) and II b) and after homogenization the rest of the water is used to set the desired solids content. 5) Dispersions obtainable by the process according to Claims 1 to 4. 6) dispersions according to claim 5, characterized in that the proportion the polyallylene oxide residues of the non-volatile fraction of the dispersion below 4% by weight lies. 7) dispersions according to claims 5 and 6, characterized in that the emulsifier resin II b) in the non-neutralized state has an acid number of 15 to 35 has. 8) dispersions according to claims 5 to 7, characterized in that Polyester and polyethylene oxide part of the emulsifier resin II b) by means of diisocyanates have been linked together. 9) Use of the dispersions according to Claims 5 to 8 for the preparation of lacquers, especially stoving lacquers.