DE2555732A1 - PROCESS FOR THE MANUFACTURING OF WATER-DILUTABLE PAINT BINDERS - Google Patents

Description

Patent attorneys
Dipl. Ing. Hans-Jürgen Müller Dr. rer. nat. Thomas Berendt

D 8 Munich 80 Lucile-Grahn-Strasse 38

VIANOVA KUNSTHARZ AKTIENGESELLSCHAFT, A -1010 Vienna I., Johannesgasse 14

Process for the production of water-thinnable eggs Paint binders

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The invention relates to a method for the production of air or oven-drying, water-thinnable paint binders Implementation of alkyd resins or epoxy resins with mod iflzierteu Aminoformaldehyde condensation products.

Environmental problems and raw material shortages have occurred in the last Years led to an increased development and application of aqueous paint systems. Alkyd resins made by incorporation are made water-compatible by polyethylene glycol, are described in many publications (e.g. US Pat. No. 2,634,245,

2,853,459, 3,333,032, 3,223,659, 3,379,548, 3,437,615, 3,437,618,

3 442 835, 3 457 206, 3 639 315 or DT-OS 1 495 031 or GB-PS 1 038 696).

The state of distribution in the aqueous system depends on the polyethylene glycol content of the alkyd resin: If the proportions are low, technically unusable "water in oil" dispersions are obtained. From about 15% polyethylene glycol "oil-in-water" emulsions are formed, the particle size of which decreases with increasing polyethylene glycol content. Above about 25 % one comes into the range of opalescent colloidal solutions (particle size below 0.5 μ). Due to the high polyethylene glycol content required for stabilization, however, such finely divided emulsions form very soft films with low water resistance. That is why they have so far not been able to establish themselves, especially in industry.

It has now been found that by reacting suitable alkyd or epoxy ester resins with products that are obtained by reaction of amino formaldehyde condensates with monomethoxy polyethylene glycol, possibly minor amounts of unsaturated Polyethylene glycols and / or compatibility-promoting monohydroxy compounds are obtained, can produce universally applicable binders for water-thinnable paints that are Process perfectly with all important pigment types and provide films with good water resistance. It can with it .both air-drying and (by adding water-thinnable Aminoforraaldehyde resins) oven-drying paints

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be formulated.

The present invention thus relates to a method for Production of water-thinned laek binders, soft

are characterized in that nan

- 50 wt .-% of a preferably solvent-free, with Moiioalcohols with 1-4 carbon atoms largely to completely etherified aminoformaldehyde condensate with

50-92% by weight of sonomethoxy polyethylene glycols (polyethylene glycols etherified on one side with methanol) with an average molecular weight of 300-2000, preferably 400-1000, given in a mixture with minor amounts of unetherified polyethylene glycols with an average molecular weight of 300-2000 and / or optionally compatibility-promoting ilonofeydroxy compounds, the hydrocarbon radical of which contains 4-42 C atoms and optionally ester or ether bridges , is converted at 90-200 ° C. and
- 30% by weight of this reaction product combined with - 95% by weight of an alkyd resin or epoxy ester resin, indeir the reaction product is mixed with either the whole amount or with part of the alkyd or epoxy ester resin at 50-150 ° C until it is optimally dilutable with water and optionally then admixing the remainder of the alkyd or epoxy ester resin and

the product obtained is ^{diluted at 50-90 3} C by the slow addition of water, which preferably contains between 0.1-3 % of an inorganic or organic nitrogen base.

The dilution can be ir. "the usual synthetic resin plants or similar stirred tanks cr-

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follow. The use of special, high-speed dispersing equipment is only in special cases, i. H. at very little Percentage of methoxypolyethylene glycol or, when using neutral water for dilution, necessary. Depending on the formulation either transparent emulsions or opalescent colloidal solutions arise. Because of the small particle size there are no stability problems as with coarse emulsions.

Both air-drying and oven-drying binders can be produced. In oven-drying paints, the binders according to the invention with crosslinking agents, such as. B. water-soluble amino formaldehyde resins combined. All common types of pigments can be used to produce paint. The familiarization does not cause any particular problems. In contrast to most known binder emulsions, the 3-roller mill can also be used to rub in. The result is lacquers that are superior to all known alkyd resin and epoxy resin egg emulsions in terms of the sum of their properties (stability, flow, gloss, drying, water resistance).

The reason for the superiority of the binders according to the invention lies in the strictly airphipatic structure of the molecules effective as emulsifiers from hydrophobic and hydrophilic segments. This build-up is achieved through the stepwise condensation, whereby the amino formaldehyde condensate is first transetherified with the (monomethoxy) polyethylene glycol and optionally with the compatible η monoalcohol and the resulting reaction product is then reacted under gentle conditions with the alkyd resin or epoxy resin . This structure allows the hydrophilic methoxypolyethylene glycol chains to develop their full potential, while this is only very imperfectly the case with the statistically distributed polyethylene glycol chains in the known water-thinnable alkyd resins.

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All known types can be used as alkyd resins
as long as they meet the following conditions:

1. The intrinsic viscosity is not more than 10 ml / g, genessen in chloroform at 20 ⁰ C, liegen.'Das is necessary so that
there is sufficient leeway for the misclicondensation with the polyethyleneglyco! modified aminoformaldehyde condensate.

2. The hydroxyl number must be at least 40 mg KOH / g so that sufficient functional groups are present for the co-condensation. In the case of air-drying alkyd resins, the
Hydroxyl number generally between 40 and 100, for oven-drying types between 80 and 250.

3. The acid number should be between 10 and 50 mg KOH / g. The carboxyl groups make a very significant contribution to the stability of the emulsions, especially when nitrogen bases are present in the aqueous phase. With increasing acid number can
therefore the content of methoxypolyethylene glycol in the end product can be reduced. At acid numbers above 50, however, the water resistance of the films decreases. With acid numbers below 10, a sufficiently fine emulsion can only be obtained with very high polyethylene glycol contents.

The type and content of fatty acids can be varied within the generally usual limits, depending on the area of application. For air-drying lacquers, alkyd resins with a content of 20 - 70 % of highly unsaturated fatty acids (e.g. soy, tall oil, linseed oil fatty acids, etc.) are suitable. For oven-drying lacquers, alkyd resins with a content of up to 55 % of unsaturated or saturated Ricin fatty acids are particularly suitable as unsaturated and coconut or isononanoic acid as saturated fatty acids.

the fatty acid-modified alkyd resins can iv.r cfentrocknende Emulsions also oil-free alkyd resins can be used.

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Urethane-modified alkyd resins are also particularly suitable, d. H. those alkyd resins in which some of the dicarboxylic acids have been replaced by diisocyanates.

In addition, polymerizable monomers (e.g. Styrene, vinyl toluene, acrylic acid and methacrylic acid esters) modified Alkyd resins are used.

Fatty acid esters of epoxy resins of the bisphenol A type with a maximum average molecular weight of 2000 can be used as epoxy ester resins, whereby a limiting viscosity number below 12 must be achieved during the esterification by gentle conditions. The fatty acid content can be varied between 30 and 60%. Castor, soy, linseed oil or tall oil fatty acids are preferably used. Following the fatty acid esterification, which should be driven to an acid number below 5, the acid number must be increased to 10-30 mg KOH / g by adding dicarboxylic acid anhydrides (e.g. phthalic anhydride, maleic anhydride) to support the emulsifiability of these epoxy ester types.

Starting materials or. Manufacture of such alkyd and epoxy ester resins are known to the person skilled in the art and are e.g. B. in the book Wagner Sarx '(4th edition, 1959) described in detail.

As aminoformaldehyde condensates are low molecular weight, largely νetherified melamine, benzoguanamine and urea resins ■ suitable. The degree of etherification should be at least 75%. The ethereal alcohols are mainly methanol and ethanol, in addition, propanols and butanols are also possible. They are preferred because of their low molecular weight and high functionality in the case of low reactivity, products of the hexamethoxymethyl melamine type

The monomethoxy polyethylene glycols used are products with an average molecular weight of 300-2000. With

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increasing chain length decreases the water dilutability of the End products too. However, since the tendency to crystallize increases in the same sense and this leads to compatibility problems with some products result, molecular weights of 400 1000 are preferred. In a mixture with the monomethoxy polyethylene glycols It is also possible to use proportions of unetherified (i.e. divalent) polyethylene glycols with an average molecular weight between 300 and 2000 can be used. Because of the resulting increase in molecular weight, the proportion may the divalent polyglycols should not be chosen too high. For example, a maximum of 2 moles of hexamethoxymethylmelamine should be used 1.5 mol of bivalent polyglycol can be used.

Compatibility-promoting monohydroxy compounds are monohydroxy compounds whose hydrocarbon radicals have from 4 to 42 carbon atoms, and these compounds can also contain ether or ester bridges.

The task of these compounds is to check the compatibility of the alkyd or epoxy ester resin with the modified one in critical cases To convey aminoformaldehyde condensate and thus to create the conditions for an optimal implementation.

The selection depends on the alkyd or epoxy ester resin to be emulsified, i. H. there will be such connections used whose hydrocarbon radical is able to solvate the resin in question.

Fatty alcohols, preferably those derived from unsaturated fatty acids, and partial esters of fatty acids and polyalcohols with a free hydroxyl group are suitable for long-oil alkyd resins. For oil-free alkyd resins, branched or cyclic alcohols with 4-12 carbon atoms, such as 2-ethylhexanol or cyclohexanol, are well suited. In epoxy resins z. B. Trimethylolpropane diallyl ether proven. Alkyd resins with an oil content between 20 and 50 7c usually do not require a compatibilizing component,

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In the process according to the invention, the amino formaldehyde condensate is first used with the mono-methoxypolyethylene glycol, optionally with the addition of limited proportions of unetherified polyethylene glycol and / or tolerability-promoting Monohydroxy! Connections at 90 - 200 "C uage ether. For speeding up The ethereal reaction can make small amounts more acidic Catalysts, e.g. B. p-toluenesulfonic acid can be added. The response is measured by the amount of the ethereal released alcohol, through viscosity measurements and tracked by checking the water dilutability. The catalyst is then added by adding an equivalent amount of a basic compound (e.g. Ca-naphthenate or Triethylamine rendered ineffective.

(Preferably 70-120 ⁰ C) then the modified amino resin with the alkyd resin or Epoxiesterharz bel50-150 ^o C is mischkondensiert. It can be advantageous to use only part of the alkyd resin or epoxy ester resin for the conversion and to mix the resulting "emulsifier resin" with the remaining alkyd or epoxy ester resin. As a result, a more complete conversion or linking of the components can be achieved without an unfavorable shift in the HLB value (“hydrophilic / lipophilic balance”) of the emulsifier molecules formed. The reaction is controlled by checking the water dilutability and by measuring the limiting viscosity number. Adherence to the specified sequence of reactions is essential to achieve water-thinnable binders with good properties. '-''

By correct choice of medium molecular weight, functionality and quantity ratio of the precursors must be ensured that the optimal water dilutability at the same time the desired limit viscosity range is reached. Depending on the nature and application, the binders apply to this area approximately the following limits (measured in chloroform at 20 ° C):

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oven drying alkyd resins 5-10 ml / g

oven drying epoxy resins 8-14 ml / g

air drying alkyd resins 8-16 ml / g

air-drying epoxy-ester resins 12-20 ml / g

After the desired values have been reached, the reaction is ended by cooling, optionally by adding the remaining alkyd or epoxy ester resin and by slowly adding the water. Small amounts (0.1-3%) of ammonia or an organic amine can be added to the water to support the solvation of the resin. By choosing the type and amount of the base, the particle size, viscosity, stability, etc. of the emulsion formed can be influenced. Most of the products according to the invention can be diluted so easily that the agitator of a normal alkyd resin kettle is sufficient to incorporate the aqueous phase. A special dispersing device (e.g. of the Ultra-Turrax type) is only required for products with a very low content of (monomethoxy) polyethylene glycol and a low acid number or when using neutral water for dilution.

The following examples illustrate the invention without its application to limit the method according to the invention.

Composition and constants of the alkyd resins used, or of the epoxy ester resin are shown in Table 1.

The following amino formaldehyde condensates are used in the examples used:

Ml is a commercially available solvent-free hexamethoxyniethylmelamine with a degree of etherification of more than 95 %, '

M 2 is a commercially available, solvent-free hexaraethoxyethoxymethylmelamine with a degree of etherification above 75 ° C and a? .Lethoxy / ethoxy ratio of about 1: 1.

M 3 is a commercially available methylated, solvent-free Urea resin.

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All measurements of the limiting viscosity number are made in chloroform. Unless otherwise stated, all percentages are percentages by weight.

Table I.

Composition and constants of those used in the examples Alkyd or Epoxy resins

BEZ. 2 QUALITATIVE
COMPOSITION PA, PPE , PA, 1) 2) 3) 4) A. 2 TFS, RFS, _r TMP PPE 61 24 45 9.1 A. 3 LFS, TMP, , PA, PPE PSA ⁵⁾ 44 23 83 8.2 A. 4th RFS, TMP, , AS, PPE ⁶ 36 36 163 5.8 A. 5 NPG, TMP, , PA, 0 25th 159 5.8 A. 6th RFS, EP, TPSA > 42 14th 65 8.1 A. LFS, 38 21 123 9.2

Xall Oil Fatty Acid Linoleic Fatty Acid (teehn) Ricinic fatty acid Pentaerythritol neopentyl glycol

Phthalic anhydride

TPSA: tetrahydrophthalic anhydride

AS ζ adipic acid

EP: epoxy resin based on bisphenol A CIG approx. 900 - 1100)

1) Oil content (% by weight)

2) acid number DIN 53 183

3) hydroxyl number DIN 53

4) Intrinsic viscosity ml / g, measured in CHCl., At 20 ⁰ C

5) modified with styrene and methyl methacrylate

6) modified with tolylene diisocyanate

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- li -

forriaJ dehydj Example 1: 390 g of the amine conctensate .M 1, 265 g of a fatty alcohol made from linseed oil fatty acids, with an iodine number of 165, and 3200 g of methoxypolyethylene glycol (molecular weight about 800) are slowly mixed with 37 g of a 10% ethanolic p-toluene-sulfamic acid solution heated to 180 ^° C. and kept at this temperature until 191 g of distillate have been given off. In order to switch off the catalytic effect of the p-toluenesulfonic acid, after cooling to 100 ^° C., 15 g of calcium octoate (4 " _c metal content) are added, the temperature being held for 30 minutes.

150 g of this precursor are heated to 95 ° C. with 850 g of alkyd resin A 1 until the reaction mixture, when diluted with a 1% ammonia solution, gives a clear to slightly opalescent solution and the intrinsic viscosity is 11.0 ml / g.

The reaction is by adding 200 g of a 0.5% aqueous Ammonia solution and the resin by further addition of 0.5% ammonia solution to a solids content of 50% diluted.

Paint composition and checkout are examples for all summarized in Tables II and III,

formaldehyde} In game. 2: Heat 390 g of the Aminqkondensates M 2, 1000 g Methoxypolyathylenglykol (molecular weight about 500) and 1600 g Methoxypolyathylenglykol (molecular weight about 800) with 29 g of a 10% ethanolic solution of p-toluenesulfonic acid at 160 ⁰ C and holds at this temperature until 154 g of an ethanol-methanol mixture have distilled off. It is cooled and neutralized with triethylamine to pH 7.

150 g of this precursor are heated with 150 g of the alkyd resin A 2 to 90 ³ C until the reaction product has a limiting viscosity number with optimal dilutability in 1 ^ .iger ammonia solution

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-T.X2 -

of 9.7 ml / g erreicht.Man lowers the temperature to 7O ⁼ C, add a further 700 g of the alkyd resin A to 2, and diluted by mixing thoroughly with liiger Triäthylaminlösung to a solids content of 50%.

Example 3: 80 g of the precursor used in Example 2 were mixed with 920 g of alkyd resin A 3 at 100 ⁰ C up to optimum dilutability in l% ammonia solution and an intrinsic viscosity of 7.1 ml / g responding. Then it is slowly diluted with 1.5% ammonia solution to a solid. content of 50%.

tformadehydj

Example, 4: 160 g of the amine condensate M 3 and 500 g of methoxypolyethylene glycol (molecular weight about 500). are reacted with catalysis by 6 g of 10% ethanolic p-toluenesulfonic acid at 150 ° C. until 37 g of methanol have distilled off. ^{The reaction mixture, cooled to 100 °} C., is reacted for 30 minutes with 2.4 g of calcium octoate (4% metal content).

200 g of this precursor are mixed with 800 g of the alkyd resin A 3 at 90 ° CT for optimal dilutability in 1% ammonia solution and an intrinsic viscosity of 7.3 ml / g implemented. Dissolving takes place with 1% ammonia solution to a solids content of 50%.

£ Qjcna. 4 jflehv. φ Example 5: 39O g of the AminalionüexisaTes M 1 and 100 g of cyclohexanol are heated with 20 g of a 1Oxigen ethanolic p-toluenesulfonic acid solution at 120 ° C until 50 g of distillate are obtained. 1500 g of methoxypolyethylene glycol (molecular weight about 500) and 37 g of the p-toluenesulphonic acid solution are now added, the reaction temperature is increased to 170 ° C. and held until a further 126 g of methanol have distilled off. It is allowed to cool to 100 ° C., 23 g of calcium octoate (4 % metal content) are added and the mixture is kept at this temperature for 30 minutes.

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180 g of this precursor are reacted with 820 g of alkyd resin A4 at 90.degree. With maximum solubility in aqueous ammonia solution and a limiting viscosity number of 7.4 ml / g, the mixture is slowly diluted with 0.5% ammonia solution to a solids content of 50%.

far m a J.

EXAMPLE 6 780 of Amina condensate M 1, 1000 g of polyethylene glycol (molecular weight about 1000) g and 3500 g methoxypolyethylene glycol (molecular weight about 500) are heated with 157 g p-Toluolsulfonsäurelöung (lO% in ethanol) at 180 ⁰ C to 423 g of distillate have accrued. The temperature is ^{lowered to 100 1} C and, after the addition of 63 g of calcium octoate (4 % metal content), left to react for half an hour.

120 g of this precursor are reacted with 880 g of the alkyd resin A 5 at 95.degree. With maximum solubility in 1% ammonia solution and a limiting viscosity number of 10.2 ml / g, it is diluted with 1% ammonia solution to a solids content of 50%.

£ pr m & l deh vdi Example 7: One leaves 390 g of Am.inciKohcft'i-iSärSs M 1, 214 g of trimethylolpropane diallyl ether and 1500 g of methoxypolyethylene glycol (molecular weight about 500) with 1.99 g of H ₃ PO ₄ (70 ¹ Ug) as React catalyst at 160 ° C until 128 g .Methanol have distilled off. Xach cooling to 100 C ⁼ 23.4 g Kalziumoktoat added to (4% metal content) and holding 30 minutes at that temperature.

240 g of this precursor are heated with 760 g of the epoxy ester resin A 6 to 100 ° C and maintains this temperature up to a limiting viscosity number of 10.7 ml / g is reached The reaction mixture is mixed with 100 g of 0, Seiger ammonia solution and with a Dispersing device (type Ultra Turrax) emulsified for 3 minutes. Man receives a finely divided emulsion with a particle diameter of about 0.5-2 μm.

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Table II

Composition of the test lacquers produced from the inventive Binders.

Example 12345.67

as per example as 100 100 70 70 85 100

Solid resin

Titanium dioxide 100 75 100 100 100 70

Siccatives:

Co (1 % metal) 10 6.0 - - - 3.0 -

Pb (10% metal) 8.0 8.0 - -

Ca (4 % metal) 2.5

Zr (4%. Metal) -3.0- - - -.

Zn (2% metal) - - .- - - _- 3.0

Anti-skinning agent 1.0 O, 7th - 1 - 1 0 1.5 - Leveling agent 0.2 O, 4th O, 6th O, 6th . 05 - 0.05 Anti-settling agents - 0, 9 O, O, - 1.5 - Networking
component
Melamine resin "M 2" - 30th 15th 30th 15th 15th 25th p-toluenesulfone
acidic in HgO - O, O ₅ 0.15 - 0.15

The lacquers are diluted to the application viscosity with distilled water.

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Table III (paint test)

Example application

paint spray

splash

.4 .5 6 7 syringes syringes syringes

Zen

Layer thickness (μ dry film)

Gloss (long, % of black normal)

Air drying: tack-free after hours

Oriffjfest after hours

Hardness after king me 1 week

Ti clung according to Erichsen after 1 week

11,, 0 strength after 1 week (degree of blistering according to DIN 53 209)

Oven drying: stoving temperature

Burn-in time Hardness according to König Cupping according to Erichsen ΙΙ ,, Ο-strength ^x) (degree of bubbles according to DIN 53 209)

40 103

4 1/2 12

31 p

9, 5 ram

38

115

1 3/4 7

79 s 8.9 mm

m l / g 1 m l / g 1 regenerated regenerated

39
101

118

41

109

34

101

- - • 1 1/2 K) - I, - - - 145 ° 4th 1/2 cn
cn - N - ■ - - 30 min. 96 S. CO - - - 141 s 8th, 2 mm 150 ° - - 5.8 mm m 0 / g 0 30 min. m 0 / g 0 110 s 150 ° 150 ° - 7.5 mm 30 min. 30 min. m 0 / g 0 115 s 91 p - 6.3 mm 7.8 mm m o / g 0 m 0 / g 0

x) Test by immersion in distilled water at 40 ^° C. for 48 hours.

Claims (6)

Patent claims: 1. Process for the production of water-thinnable paint binders based on alkyd resins or epoxy resins, characterized in that one 8-50% by weight of a preferably solvent-free aminoformaldehyde condensate that is largely to completely etherified with monoalcohols with 1-4 carbon atoms
with - 92 wt .-% of Monomethoxypolyäthylenglykolen (one side with methanol etherified polyethylene glycols) having an average molecular weight of 300 - 2,000, preferably 400 to 1000, optionally in mixture with minor amounts of unverätherten polyethylene glycols with an I-average molecular weight of 300 - 2000 and / or optionally Compatible monohydroxy compounds, the hydrocarbon radical of which contains 4-42 C atoms and possibly ester or ether bridges, is converted at 90-200 ° C
and 5-30 % by weight of this reaction product with - 95% by weight of an alkyd resin or epoxy ester resin combined, by treating the reaction product either with the whole amount or with a part of the alkyd or epoxy ester resin at 50 150 ° C until it can be diluted with water mixed condensation and, if necessary, the remainder of the alkyd or epoxy ester resin mixes in and the product obtained is diluted at 50-90 ° C. by the slow addition of water, which preferably contains between 0.1-3 % of an inorganic or organic nitrogen base. 609826/1008 2. The method according to claim 1, characterized in that the amino formaldehyde condensate with the methoxypolyethylene glycol, if necessary in a mixture with minor amounts on non-etherified polyethylene glycols and / or other vonohydroxy compounds in the presence of an acidic catalyst, preferably p-toluenesulfonic acid, implemented. 3. The method according to claims 1 and 2, characterized. that is used for the co-condensation alkyd resins obtained by an intrinsic viscosity of not more than 10 ml / g, measured in chloroform at 20 ⁰ C, a hydroxyl number of at least 40 mg KOH / g and an acid number between 10 and 50 mg KOH / g are characterized. 4. Process according to Claims 1 and 2, characterized in that epoxy ester resins are used for the mixed condensation, measured by a limiting viscosity number of a maximum of 12 ml / g in chloroform at 20 ° C, a fatty acid content of 30-60% by weight and an acid number between 10 and 30 mg KOH / g are characterized. 5. Process according to claims 1 to 4, characterized in that that in a mixture with the monomethoxypolyethylene glycol a maximum of 0.75 mol of unetherified polyethylene glycol per Mol of the amino formaldehyde condensate used. 6. The method according to claims 1 to 5, characterized. that the condensation with the alkyd or epoxy ester resin up to a limiting viscosity range, measured in Cnloroforrr. at 20 ° C from 5-10 ml / g for oven-drying alkyd resins or 8-14 ml / g for oven-drying epoxy resins or 8 - 16 ml / g for air-drying alkyd resins or 12 - 20 ml / g for air-drying epoxy resins »~ Taking into account the optimal water thinnability performs. 609826/1008