DE1805188C3 - Coating agents - Google Patents

Description

The invention relates to liquid coating agents based on a mixture of binders and organic solvents or water and additives which make the binder water-soluble or optionally also solvent-free additives Basis that acts as a binding agent!

A) 50 to 10 percent by weight of aminoplasts and / or their low molecular weight, defined precursors and

B) 50 to 90 percent by weight of hydroxyl-containing and carboxyl-containing polyesters from aliphatic polyols, ethylene glycol and optionally other diols on the one hand as well as aromatic and aliphatic dicarboxylic acids

on the other hand

optionally contain in addition to customary auxiliaries, the binder also by co-condensation of aminoplasts and / or their low molecular weight defined precursors with the polyesters or durcli Mixed condensation of the starting products of the aminoplast production with the polyesters has been produced can be.

It is known that so-called oil-free alkyd resins in combination with aminoplasts for the production of gap films are suitable. The paint films made from these polyesters are said to be at a given Flexibility have excellent hardness, in particular the polyesters au; Neopcntylglycol u / id made using Glycidyls of monocarboxylic acids, the 9 hi < Contain carbon atoms and the carbon chain of which is branched in position to the carboxyl group.

should distinguish manufactured polyesters (H. L. Gerhardt and E.E. Parker, Ind. Engng. Chem. 59, No. 8, 42 [1967]).

Also in the USA.-Palentschrift 28 60 119 and in the publication by D. L. E d w a r d s, D. C. F i nn e y and P.T. von Bramerin Deutsche Farbenzeitschrift, 20, 519 (1966), oil-free alkyd resins based on diols or polyols with a neopentyl structure are used described which, after crosslinking with aminoplasts, paint films with good chemical resistance, should result in high hardness and good flexibility. As our own comparative tests show Such oil-free alkyd resins can only be produced with difficulty; in addition, although they are hard, but only relatively little elastic (see comparison example 1).

From the USA.-Patent 32 07 715 is still known that polyester from trimellitic anhydride, neopentyl glycol and adipic acid in combination with Tetrakis (alkoxymethyl) benzoguanamines paint films give good chemical resistance and good Should have flexibility. However, the values given in this patent show that the Although the flexibility of these paint films is comparatively improved, their absolute values are still are very low.

In US Pat. No. 3,158,584, alkyd resins are made from a phthalic acid, a polyhydric alcohol and a dimer of an unsaturated aliphatic monocarboxylic acid containing 14 to 22 carbon atoms contains, described which, in combination with aminoplasts, result in lacquer films that result from characterized by the combination of hardness and elasticity. The lacquer films produced in this way, however, tend strong to yellowing and are not sufficiently resistant to solvents.

In US Pat. No. 24 60 186 polyesters from 2-ethylhexanediol- (1,3) are used as plasticizers by exceptional value for use in urea-formaldehyde or melamine-formaldehyde condensation products described. The coatings obtained according to this information are in part stretchable and impact-resistant, but too soft (see comparative example 2).

Also in the company publication »1,4-Cyclohexanedimethanol« of the Eastman Kodak Company of July 1965 describes oil-free alkyd resins made from Pelargonic acid, phthalic anhydride, pentaerythritol, neopentyl glycol and 1,4-bis (hydroxymethyl) cyclohexane and should be both hard and elastic. These polyesters also meet not the expectations placed on them, as our own experiments show (see Comparative Example 3).

From GB-PS 8 15 179 (= US-PS 29 15 486 and 29 15 487) are water-dispersible coating agents known, soft, in addition to aminoplasts and optionally customary alkyd resins, polyesters with molecular weights included between 800 and 1500. The polyester must but at least 25 mole percent, preferably more than 50 mole percent, of a polyol having at least three Contain hydroxyl groups.

In ('he US-PS 29 36 296 branched polyesters are described, which, however, for the usual Blcchbeschichungsverfahren are unsuitable. Baking temperatures of around 400 ° C and as a solvent are used only strongly polar, high-boiling phenols, such as, for example, cresol, are given. Further the publication shows that the polyesters are made of a number of resins, such as silicone resin, Polyamides, polystyrene and the like can be mixed in. Urea condensation resins are also used called. The US-PS 29 36 296, however, in no case can be inferred that branched polyester Particularly in connection with condensation resins, they result in particularly excellent coatings on sheet metal. In US-PS 33 38 743 wire enamels are based on polyesters and small amounts of

ίο described an aminoplast. With these paints First and foremost, good temperature resistance is important. Information about the elasticity of the The coatings obtained from these wire enamels cannot be found in the patent.

J5 US Pat. No. 3,370,975 claims the improvement the adhesion of alkyd / aminoplast resin systems to the respective substrates.

Adducts made from polymers containing free hydroxyl groups are used as additives to improve adhesion and dicarboxylic anhydrides !! used. True will for the production of these adducts in addition to copolymers from z. B. allyl alcohol and styrene, polyethers, polyvinyl alcohols ^ modified polyvinyl chlorides and epoxy resins, polyesters are also used, but the composition of these polyesters just as little information is given as about the composition of the alkyd resins.

There are also a number of solvent-free or low-solvent coating agents known, which avoid the disadvantages caused by solvents, but others are often undesirable and have unfavorable properties (cf. W. A. Riese, "Löserfrei Anstrichsysteme", Curt R. Vincentz-Verlag, Hanover, 1967). For example

3.5 wise most of them are made on the basis of polyvinyl chloride Plastisols are not sufficiently resistant to chemicals and, in particular, are not resistant to solvents; about it In addition, losses of plasticizer often result in embrittlement of the coatings. The solution

4.0 medium-free usable epoxy systems have, in addition to their very advantageous properties, a number of Disadvantages: In addition to the health hazards and odor nuisance caused by the hardener to be used fall in particular here

The processing times of finished coating mixtures weigh heavily, the difficulties in the workflow and the use of two-component spray guns condition. The already short processing time of epoxy resin systems becomes solvent-free with Application shortened even further. The unsaturated polyester resins have similar disadvantages of which, in addition to the short processing times of finished mixtures, in particular the The hardening reaction is sensitive to air, which is only due to the addition of wax or due to Use of very special resins is to be dubbed. Finally, with the polyurethane systems are again the short processing time and the health hazard caused by the isocyanates to mention, but also the strong water sensitivity of the crosslinking reaction, which is at Insufficient water exclusion leads to the formation of defects and bubbles in the coating.

One has therefore already tried hard, too to develop solvent-free coating agents based on aminoplasts.

So in the DT-AS 1101667 and DT-PS 12 31833 solvent-free stoving enamels on the

The basis of aminoplasts is described, which are contained by at least 2 carbon atoms in that aminoplast solutions are to be separated from one another,
Lent plasticizers are added and then the solvent is distilled off. As existing, and mixture III

Sonders suitable plasticizers are hydroxyl- 5 _{"u 2U 91-33 Mo} i _pro2 ent, preferably 75 grupnenhaltige Wcichmachungsmittel such. B. Ribjs _{50 mole percent} , _{f from} one or more zinusöl, called; However, there are also hydroxyl aromatic or cycloaliphatic.! Dicarbongruppenfrc.e plasticizers such as petroleum distillates or _s - _{acids undjodtn dercn} derivatives and
Usual phthalate We.chmacher used. _{T he} from, “ _{2 2U 9 bjs 6? Mo} , _percent preferably 25 to such a coating agent by baking, 10 _{5Q MoJprozcn} , _{from one of} the several aligated coatings have only low solvent-phatic dicarboxylic acids with 4 to 12 carbon strength and low chemical resistance material atoms and / or their derivatives
on, approach badly to metals and have about it
in addition, unsatisfactory mechanical properties. consists.

From the earlier patent application DT-OS 15 95 857 »5 As polyols are z. B. glycerol, trimethylolethane, special aminoplasts are known, which alone are also suitable in trimethylolpropane and pentaerythritol; the solvent-free form can be used. Use of glycerin is preferred.
The cover films produced from them are hard, but very brittle and inelastic as they are to be used in smaller quantities. Combinations of diols in which the hydroxyl functions are separated by 2 to these special amino resins with conventional lacquer 20 8 carbon atoms and optionally resins should be solvent-free processable, but up to 2 of the carbon atoms are very viscous and such mixtures can be replaced by oxygen atoms Which, in turn, can only be applied with great effort and 2 carbon atoms are separated from each other, also lead to coatings that are by no means suitable for example. B. propanediol (1,2), propanediol (1,3), better than coatings from conventional raw materials 25 butanediol (1,2), butanediol (2,3), butanediol (1,3), busind . tandiol- (1,4), 2,2-dimethyl-piOpandiol- (1,3), hexane in the earlier patent application DT-OS 17 94 232 diol- (1,6), 2-ethylhexanediol (1,3 ), Cyclohexandiwerdcn also binders for coatings be oi- (1,2), cyclohexanediol (1,4), 1,2-bis (hydroxymeschricben, which from a polyester and an aminoethyl-cyclohexane, 1,3- Bis- (hydroxymethyl) -cyclohexane, plastic. In contrast to the present invention, 30 M-bis-hydroxymethylJ-cyclohexane, .v, 8-bis- (hyfindung is powder and not hydroxymethyl) -tricyclo- [5, 2, ^{1.0 2> 6} ] -decane, where χ stands for 3, liquid products. The document does not stand for 4 or 5, diethylene glycol, triethylene glycol, dizu can be found in the extent to which the composition and molar propylene glycol or tripropylene glycol The phase of the product tables can have diols in their cis or trans form. In addition, the products contain over or a mixture of both forms, mainly aminoplasts The object of the invention is based on cal or cycloaliphatic dicarbonic compounds. Overacids are z. B. phthalic acid, isophthalic acid, Hcxazügen which combine high elasticity with hydroterephthalic acid, hexahydrophthalic acid, Hcxagroßcr hardness and also not hydroisophthalic acid and also z. B. Tctrabromphthal tend to yellow. 40 acid suitable, with the cycloaliphatic dicarboxylic This object was surprisingly achieved in that acids in their trans or cis form or as a mixture that coating agents have been found in which both forms can be used. The VerKomponente B polyester with average molecular weights turn of dicarboxylic acids, in which the carboxyls between 600 and 3000 are used, which are arranged by groups in 1,2-pieces, in particular esterification of mixtures I and III produced 45 of phthalic acid and hexahydrophthalic acid, is present , Mixture I being preferred.

Suitable aliphatic dicarboxylic acids are

1.1 to 1 to 33 mol percent, preferably 10 to especially succleic acid, glutaric acid, adipic acid, 30 mole percent, from one or more all-suberic acid, sebacic acid. Decanedicarboxylic acid or phatic polyols with 3 or 4 hydroxyl-2,2,4-trimethyladipic acid. The use of aliphagruppcn and 3 to 6 carbon atoms and table dicarboxylic acids with 4 to 6 carbon atoms,

1.2 to 99 to 67 mol percent, preferably 90 to in particular of adipic acid, is preferred.

70 mole percent, from a mixture 11 of ali- Instead of the free dicarboxylic acids, you can also use

phatic and possibly cycloaliphatic ^! their esters with short-chain aicanols, e.g. B. dimethyl,

Diols 55, diethyl or dipropyl esters, can be used. Provided

the dicarboxylic acids can also form anhydrides

there is, in turn, these are used, z. B. phthalic anhydride,

Hexahydrophthalic anhydride, succinic anhydride

II. 1 to more than 70 to 100 mol%, preferably three or glutaric anhydride.

80 to 100 mole percent, obtained from ethylencnglycol 60 coatings with particularly good properties

and when using polyesters with medium

11.2 to less than 30 to 0 mol percent, preferably molar weights from 800 to 2500, in particular from 1000

up to 20 to 0 mol%, from one or more up to 2000, which predominantly contain hydroxyl groups,

other aliphatic or cycloaliphatic !! d. H. with a molar excess of alcohol

Diols in which the hydroxyl functions have been produced by poncntc (diol and polyol).

2 to 8 carbon atoms are separated and

at most up to 2 of the carbon sellers by known and customary methods, with or without

Oxygen atoms can be replaced, the re-catalyst, with or without reading through an inert

8 05 188

gas flow, as solution condensation, melting ends - the hardness of the films, while their elasticity increases

sation, or azeotrope esterification, at temperatures. The opposite is true for larger molar ratios

up to 250 "C or higher, with polyol to diol reducing the flexibility of the paint films.

the released water or the released changes and their hardness improved. ! Knowing this

Alkanols! Are continuously removed. According to the 5 rules, it is possible without difficulty to

Esterification proceeds almost quantitatively and can be used for the polyester by mening the stressed area

Determination of the hydroxyl and acid numbers pursues the respective purpose of the invention

will! The molecular weight of the polyester can be selected in the coating agent with optimal properties,

simply about the use ratio of Aiko. The known aminoplasts are suitable

holkqmponetite (diol and polyol) and dicarboxylic acid io reaction products of aldehydes, in particular

regulate. For this purpose, for the production of polyformaldehyde, with several amino or amide p-

esters with predominantly hydroxyl groups on η mol groups in question, such as. B.

Diol and m mole polyol («+ m - 1) mole dicarbon melamine, urea, Ν, Ν'-ethylene urea, dicyan

acid used. However, should polyester made diamide and benzoguanamine. Are also suitable

which contain predominantly carboxyl groups, 15 mixtures of such products. Particularly good

this is how the amount of di- is calculated, the amino modified with alcohols are suitable

carboxylic acid according to the formula plastic.

M = -4- m (x - 1) + 1 Because of the sometimes limited compatibility

~ these resinous products with the invention

in which M the amount (in mol) of dicarboxylic acid to be used polyesters are preferably the

indicates that must be used when a carb- low molecular weight, defined precursors of amino

polyester containing oxyl groups from «Mol diol plasten with those to be used according to the invention

and m moles of a polyester containing χ hydroxyl groups are practically unlimitedly miscible, one

Polyol is to be produced. Usually are set. Such defined precursors of amino

the Vereslerungsbedingungen chosen so that the as are plasten z. B. dimethylolurea, tetramethylol-

Reaction is as complete as possible, d. H. until the acid benzoguanamine, trimethylolmelamine or hexame-

number of approaches that involve the production of hydroxyl thylohnelamine, which is also partially or completely

groups containing polyester serve, smaller than ethereal form, z. B. as dimetboxymethylurea,

Is 7 mg KOH / g. In approaches to the production of carb tetrakis (methoxymethyl) benzogiuanamine, tetrakis

polyester containing oxyl groups is as long as 30 (ethoxymethyl) benzoguanamine or. Polyether des

esterified until the hydroxyl number is below 7 mg KOH / g hexamethylolmelamine, such as hexamethoxymethylmelamine

located. amici or hexabutoxymethylmelamine, are used

The esterification temperature is chosen so that can.

the losses of volatile substances are low. However, it is also possible to keep the miscibility between d. i.e., at least during the first period of time, seeing the resinous aminoplast and the space of the invention the esterification is carried out at a temperature according to the polyesters to be used as well as their esterified, which under the boiling point of the poorest tolerability during stoving thereby to boil Starting substance lies. mend that one of the mixture of solutions

When producing the polyester, care should be taken to ensure that polyester and aminoplast contain certain amounts (up to that both the molecular weight of the polyester and 40-50 percent by weight, based on the total amount of its composition, influence the properties of solvents) of high-boiling polar solvents from them have produced paint films. When for both resins, such as. B. Ethylglykol, Äthylglykolhigher average molecular weights, the acetate, butylglycol or cyclohexanone is usually added or the hardness of the paint film is reduced; while the elasticity, but preferably polyester and aminoplast, increases in number, on the other hand, in the case of low molecular weights, in substance or preferably in soldering, the flexibility of the lacquer film is converted with one another at the same time, taking care to increase the hardness. Has a similar effect that the reaction does not continue until crosslinking also differences in the composition of the progresses. This can e.g. B. by briefly heating polyester from: With a higher proportion of aliphatic of the mixture or the common solution of the dicarboxylic acids and with a greater chain length of the 50 two resins, optionally in the presence of an aliphatic dicarboxylic acids, the elasticity of the catalyst, such. B. organic or mineral of the paint film, while its hardness reduces acids, are accomplished. It is also possible will. Conversely, with an increasing proportion of the polyester to be used according to the invention, aromatic and / or cycloaliphatic dicarbonic acid before or during the production of the aminoplastic acids in the polyester, the paint film harder and less than 55 resins from z. B. urea, benzoguanamine or MeI-flexible. The diols have a similar influence: adding amines and aldehydes to the batch, with the increasing chain length of the open-chain diols it is of course also possible, in addition and with increasing proportion of these diols in the usual alcohols to modify the polyesters thus formed, the paint film becomes softer and more flexible. Use plasticized aminoplastic resins as well. However, they are used in the production of polyester 60. Methods for producing such plasticized diols with short and branched carbon-amine-aldehyde resins both for solvent-containing material chains or with cycloaliphatic rings, as well as for aqueous paint systems are known,
If the lacquer produced from these polyesters is combined with the films according to the invention, as a rule with increasing proportion of these polyesters, a large number of handis diols are harder and less elastic. The mole of common aminoplasts or their defined precursor ratio of polyol to diol is also available for mechanical purposes.

Properties of the paint films are of importance: With ab- For the production of the coatings are usually

As the molar ratio of polyol to diol increases, polyester and aminoplast or their defi

9 ίο

nated precursors in common paint solvents, such as a wealth of good properties. They are, for example, propano !, iso-propanol, butanol, ethyl gloss, very easy to pigment and excellent in acetate, butyl acetate, ethyl glycol, ethyl glycol acetate, resistant to yellowing. If the coating of a butyl glycol, methyl ethyl ketone, methyl isobutyl ketone, heat aging subjected to 72 hours at 100 ⁰ C. Cyclohexanone, trichlorethylene or mixtures of 5 no visible yellowing can be observed; also various such solvents, dissolved. It is a heat aging of 72 hours at 150 ⁰ C has of course also possible and economical coatings of the invention as vergübungslichen reasons recommended that more or less resistant from. The coatings are resistant to large amounts of less polar solvents such as solvents such as xylene, gasoline-benzene mixtures, e.g. B. benzene, toluene, xylene or higher-boiling esters and ketones. In addition, they have an aromatic cut to be used in the context of the solubility of the weatherometer according to the invention, they show an excellent corrosive polyester and their compatibility with the anti-sion effect and weather resistance,
any aminoplasts used can be selected; 15 The most outstanding property of the coatings produced according to the invention, often with a proportion of up to 80% and more in the solution, is, however, their large medium mixture. Elasticity with high hardness.

When using polyesters with a high acid number, the elongation behavior of coatings is

d. h: in the case of polyesters, a large number of which are not described comfortably by the fact that the Erichsen

have esterified carboxyl groups, it is self- »» cupping test (according to DIN 53 156) and as

Understandably, it is also possible to use aqueous solutions to measure the extensibility of the deepening of the lacquered

put. According to the known and customary sheet metal, this can indicate in mm at which the lacquer layer will tear

Methods are carried out, whereby the carboxyl begins as a rule. It is essential for this test method,

groups completely or partially neutral with amines! - that the deformation of the coating takes place slowly

and if necessary also with 25 (feed: 0.2mm / sec).

Water-miscible solvents are also used. An indication of the behavior of excess

those who serve as solubilizers. Of course, if a deformation occurs suddenly, the delivers

it is so-called impact depth measurement in the production of aqueous lacquer solutions. This measurement

It is necessary to dissolve aminoplasts which are soluble in water, for example with the impact deepening device 226 / D

turn; the defined precursors of the aminoplasts 30 from Erichsen, Hemer-Sundwig, were carried out

are also particularly suitable for this purpose. will. This device uses a hemisphere

The weight ratio polyester to aminoplast has a radius of 10 mm due to a falling weight

between 50:50 and 90:10, preferably from the back of the paintwork into the sheet

between 65:35 and 85:15, fluctuate; that pressed in for the borrowed. By changing? the height of fall

Depending on the intended use of the paints, the optimum weight can be varied. It will

Ratio, the cupping value (in mm) at which the

detect. It must be taken into account that the lacquer layer often begins to crack. (The ones in the examples

by increasing the proportion of aminoplast, the hardness of the values given were obtained in this way.

Paint films increased and their elasticity decreased. In some examples, the value is > 5 ram specified,

is, while with lowering of the aminoplast 40 because the described device with the rule for

Partly, the hardness decreases and the flexibility is reduced

takes. allows greater cupping.)

The total binder content of the paints can vary as in the description of the prior art

was carried out according to the intended use within the usual limits and proven by comparative tests

vary. 45 turns, coatings made of polyesters and amino

The lacquers can use the usual additional and auxiliary plastics known, which are stretchable and also one

contain substances, such as pigments, withstand leveling and impact stress. These coatings

agent and additional other binders, such as. B. but have very low hardnesses (according to DIN 53 157)

Epoxy resins and silicone containing hydroxyl groups. On the other hand, coatings of high hardness are known,

resins. 50 which are or are only slightly or not elastic

The varnish obtained is applied and when the temperature is elastic, but there are a number of other disadvantages,

temperatures between 100 and 250 ⁰ C burned in. The like tendency to yellow and only poor

The crosslinking reactions taking place in the process will be solvent resistance. On the other hand-

catalytically accelerated by acids. When used, the coatings obtained according to the invention exhibit

formation of polyesters with a very low acid number 55 both high elasticity and great hardness,

acidic substances can therefore be added to the paint, but not the disadvantages mentioned.

will. When adding, for example, 0.5% p-To- This property profile gives the coatings a

luenesulfonic acid (based on the total binder) versatile application. In addition to painting

networking is greatly accelerated. Due to large individual parts that are exposed to impact stress

The addition of acids can also be used at room temperature 60, especially when it comes to painting materials

make drying coatings. into consideration, the retrospectively - z. B. by punching -

Can also be deformed by converting a low-acid poly
esters with about 1 to 5% of an anhydride a relative

strongly acidic dicarboxylic acid, e.g. B. Maleic anhy- polyester production

drid, you can determine the acid number of the polyester 65 A mixture of 372 g of ethylene glycol (6 mol) 184 g

increase in a safe way and so without the addition of strong glycerine (2 mol), 444 g phthalic anhydride (3 mol)

acidic substances lower the baking temperatures. and 438 g of adipic acid (3 moles) is added with stirring

The cover pulls produced according to the invention have a weak stream of nitrogen passing through them

-Temperaitur scheduling time heating by the following: 2 hours at 140 ⁰ C, 2 hours at 160 ⁰ C, 4 hours at 180 ⁰ C, 4 hours at 190 ⁰ C and 40 hours at 200 ° C. During this time, a total of 144 g of water are separated out. The mixture is then stirred for 15 minutes at S 200 ° C. and a vacuum of 20 torr. The pale yellow resin has an acid number of 2.0 mg KOH / g and a hydroxyl number of 225.5 mg, which corresponds to an average molecular weight of 740. The polyester is dissolved in a mixture of 5 parts by weight of xylene, 1 part by weight of butanol, 2 parts by weight of ethyl acetate and 2 parts by weight of ethyl glycol acetate to form a 60% solution.

Increasing the acid number of a polyester

1.2% maleic anhydride (based on the pure polyester) is added to the melt of a polyester with a low acid number. After the added anhydride has completely dissolved, the mixture is ^{heated to 120 °} C. for 1 hour, as a result of which the acid number of the poly ao ester is increased by 8.56 mg KOH / g.

The acid number of a polyester is usually increased in the melt, however there is no difficulty in the same reaction in the solution of the polyester under the mentioned as To carry out reaction conditions; However, care must be taken that the solvent does not contains functional groups which, under the reaction conditions mentioned, also with the Acid anhydride can react.

Manufacture of a lacquer

The solutions of the polyesters in suitable solvents, usually a mixture of xylene and a polar solvent, are mixed with a commercially available 55% solution of a melamine-formaldehyde condensate in a xylene-butanol mixture (1: 1) or with a commercially available hexamethylolmelamine derivative mixed in the desired solids ratio. To set a polyester to melamine resin ratio of 7: 3, throw, for example, 117 g of a 60% solution of the polyester mixed with 54.5 g of the above-mentioned melamine resin solution; should polyester and melamine-formaldehyde condensate not be compatible with each other, the mixture of solutions - at säuirearmep. Polyesters with the addition of 0.5% p-toluenesulfonic acid, based on the total amount of polyester and aminoplast, ^{heated to 50 to 100 °} C. for 10 to 60 minutes.

Production of a! Paint color

To produce a lacquer color, a clear lacquer is pigmented _{with TiO 2 in a binder-pigment ratio of 2: 1.}

Manufacture and testing of coatings

For testing purposes, the clear lacquer or the lacquer color is applied to test panels and glass plates and baked. To lower the stoving temperature, lacquer solutions that use polyesters low acid number, 0.5% p-toluenesulfonic acid (based on the total binder) added The layer thickness of the films on which the test is carried out is in all examples 40 to 60 μ. The hardness test is carried out in accordance with DIN 53 157, the elasticity test in accordance with the above described methods.

Examples 1 to 8 are compiled in Table 1, the type of melamine resin used is also specified. (In the column »Type of MeI-aminharzcs« K means that a butylated melamine-formaldehyde condensate was used while HMM indicates the use of a hexamethylolmelamine derivative.) Table 2 contains the test values of the coatings made from the polyesters described in Comparative Examples 1 to 3 below became.

Table 1

at polyester Middle Weight Type of catalyst Burn-in hardness Deep Impact game out Mole ratio melamine conditions after pull deepening No. Weight Polyester too resin DIN capability Melamine resin too 53157 after TiO, DIN 53156 (Mole) (sec) (mm) (mm)

3 AG *)
1 GIy *)
1.5 PSA *)
1.5 ADS *)

5 AG
1 GIy
3PSA
2ADS

8 AG
2GIy
6PSA
3ADS

6 AG
1.5GIy
4PSA
2.5 ADS

740

1070

1910

1540

70: 30: 0

70:30:50

80:20:50

80: 20: 0

80: 20: 0

70: 30: 0 80: 20: 0 80:20:50

70: 30: 0 80: 20: 0 80:20:50

70: 30: 0 80: 20: 0 80:20:50

HMM *)

HMM

HMM

K *)

HMM HMM HMM

HMM HMM HMM

HMM HMM HMM

0.5% pTS *) 0.5% pTS 0.5% pTS 0.5% pTS 1.2% MA *)

0.5% pTS 0.5% pTS 0.5% pTS

0.5% pTS 0.5% pTS 0.5% pTS

0.5% pTS 0.5% pTS 0.5% pTS 13O ° / 3O '
130730 '
13O ° / 3O '
130730 '
130730 '

130730 '
130730 '
130730 '

130730 '
130730 '
130730 '

130730 '
130730 '
130730 '

156
139
142
135
131

148
136
128

173
165
146

153
149
142

7.9
8.5
7.2
7.4

> 10

> 5

3 to 4

4 to 5 3

> 5
> 5

> 5

> 5

8.8 4 to 5

> 5

> 5

9.1 5

13th

114

Table! (Continuation)

example

Polyester

(Mole)

Average weight to mole ratio

Type of melamine weight Polyester to resin Melamine resin j: u TiO ₁

catalyst

Baking conditions

Hardness according to DIN 53157

(lake)

TSeT-

2ieh-

ability

do

DIN

53

(mm)

Impact depth

(mm)

6 AG IPG *) 2GIy 5PSA 3ADS

5ÄG 2PG 2GIy 5PSA 3ADS

7ÄG 2GIy 5PSA 3ADS

8 AG

3 PG

4 GIy 8PSA 6ADS

1880

1760

1680

2700

70: 30: 0 80: 20: 0 80:20:50

70: 30: 0 80: 20: 0 80:20:50

70: 30i: 0 80: 20: 0 80:20:50

70: 30: 0 80: 20: 0 80:20:50

HMM HMM HMM

HMM HMM HMM

HMM HMM HMM

HMM HMM HMM

0.5% pTS
0.5% pTS
0.5% pTS

0.5% pTS
0.5% pTS
0.5% pTS

0.5% pTS
0.5% pTS
0.5% pTS

0.5% pTS
0.5% pTS
0.5% pTS

1130730 '
130 ° / 3O '
130730 '

130730 '
130730 '
130730 '

130730 '
130.730 '
130730 '

130730 '
130730 '
13073O '

164 158 151

176 169 159

168 154 136

174 161 142

8.8

7.2

> 5> 5

> 5

> 5 5

> 5> 5> 5

> 5

> 5 4

Table 2

Ver Weight melamine , catalyst Burn-in Hardness after Deep drawing Blow equal ratio poly resin conditions DIN 53 157 ability after deep example ester to melamine ■■ ' DIN 53156 resin toTiO, (sec) (mm) (mm)

1 70:20: 0 K 0.5% pTS 150730 ' 216 5.1 <1 70: 30: 0 HMM 0.5% pTS 150730 ' 217 5.1 2 70: 30: 100 K - 150730 ' 185 1.8 70: 30: 100 HMM - 150730 ' 173 6.8 1 2 70: 30: 0 HMM 0.5% pTS 130730 ' 28 9.2 > 5 70: 30: 0 K 0.5% pTS 130730 ' 24 8.3 > 5 3 70: 30: 0 K 130730 ' 177 1.5 _<1 70: 30: 0 K 0.5% pTS 130730 ' 177 1.5 70: 300 0 HMM 0.5% pTS 130730 ' 178 2.5 <! 70:30:40 K - 150730 ' 109 1.8 70:30:40 HMM - 150730 ' 105 6.0 <1 ♦) Abbreviations: AG = Ethylene glycol. GIy - = glycerine. PPE - ADS = Phthalic anhydride. HMM == adipic acid. K == Hexamethylolmelamine derivative. == Melamine-formaldehyde condensate. pTS
MA = p-toluenesulfonic acid c.
- ■ = 'maleic anhydride.

PG

(The low-acid polyester is made by reaction with the specified amount of maleic anhydride - based on the pure polyester - according to the described method on a higher acidity brought.) Propanediol- (1,2).

Comparative example 1

(Alkyd resin no. 8531 - 69 from Deutsche Fatrbenzeitschrift 20, 519 [1966])

A mixture of 257 g trimethylolpropane, 351 g ncopentyl glycol, 498 g isophthalic acid, 292 g adipic acid and 15 ml of xylene was described with precise inclusion on p. 521 of the cited reference esterified benen reaction conditions. When an acid number of 28 mg KOH / g was reached, the seeds were sown Immediately cooled with the help of ice, with an additional 500 g of a mixture for Beschiel nigung the cooling from 90 parts of xylene and 10 parts of butanol by de

15 ^ J 16

The reflux condenser was carefully added. The luenesulfonic acid (based on the binder) - from

exact adherence to the manned reaction conditions of this paint produced and 30 minutes at

and the 160 ° C stoved lacquer films taken for quick cooling are glossy and

Takes are required so that the approach does not have a hardness of 209 see, a deep drawability

- as failed attempts showed - prematurely 5 of 8.1 mm and an impact depression of 5 mm.

networked. The solution obtained was with further. ,

312 g of the xylene / butanol mixture mentioned are Example 10

thin to make a 60% resin solution. A mixture of 6.0 moles of ethylene glycol, 1.5 moles

Glycerine, 4.5 moles of phthalic anhydride and 2.0 moles

Comparative Example 2 io adipic acid is stirred and passed through a

(Example 4 from US-PS 24 60 186) heated weak nitrogen stream according to the following time-temperature plan: 2 hours at 150 ° C and

_ 148 g phthalic anhydride, 202 g of sebacic acid, 25 hours at 200 ⁰ C. The resin has an acid-278g2-Äthylhexandiol- (l, 3), 28 g of glycerol and 110 ml of 4 mg KOH / g and a hydroxyl value of xylene are slowly raised to 230 ^c C 15 138 mg KOH / g in 11.5 hours, which is an average molecular temperature and the water formed corresponds to a water weight of 1380. A separator is separated from the polyester. Produced a 70% solution in ethyl glycol acetate towards the end of the esterification, the solvent is slowly distilled off and this polyester solution is kept a selche amount of 3 hours at 230 ⁰ C. commercially available, partially methyl-etherified hexa-

ao methylolmelamins added that a polyester /

Comparative Example 3 aminoplast ratio; of 65:35 is obtained. This

.... ,, .τ- · ι τ * 1 a ^ 1 uj · mixture wüv for 30 minutes at 90 ⁰ C heated.

(Alkyd resin from the _{firm's portfolio »1, ^ Cyclohexanol- Here} ^ _{the viscosity of the Lo} ° _{clearly increases> s0}

methanol "from the Eastman Kodak Company in July _{that a preliminary} network can be concluded.

'25 Subsequently, the Reaktionsgernisch with ethyl Among the on page 11 of the company document mentioned glycol acetate to a solids content of 60% einangegebenen conditions was made from a polyester.

160 2 pelargonic acid, 300.6 g phthalic anhydride, The - after adding 0.5 weight percent p-To-

70.0 g neopentyl glycol, 95.6 g, 4-bis (hydroxymethyl) luenesulfonic acid (based on the binder) - from

cyclohexane and 133.2 g of pentaerythritol produced. The 30 this clear coat produced and 30 minutes at

The polyester obtained had an acid number of 7.6 mg. 130 ^° C. stoved paint films are glossy and

KOH / g and became 60% with xylene, a hardness of 204 seconds, a deep drawability

Solution diluted. of 3.1 mm and an impact depression of <5 mm.

Example 9 Example 11

A mixture of 5.0 moles of ethylene glycol, 2.0 moles. A mixture of 3.4 moles of ethylene glycol, 0.6 moles of glycerin, 4.5 moles of phthalic anhydride and 3.0 moles of glycerin, 1.5 moles of phthalic anhydride and 1.5 moles Adipic acid is heated with stirring and passing through adipic acid with stirring and passing through a gentle stream of nitrogen according to the following time- temperature plan: 2 hours at 150 ^° C. and 40 ° C. heated to 2 hours at 150 ^° C. and 14 hours at 200 ° C. The resin has an acid number of 25 hours at 20O ⁰ C. The resin has an acid number of 59 mg KOH / g and a hydroxyl number of 92.5 mg of 3.8 mg KOH / g and a hydroxyl number of 220 mg KOH / g, which has an average molecular weight KOH / g, which corresponds to an average molecular weight of 1480. of 650 corresponds.

The polyester obtained in this way is used in a 45 To produce a clear lacquer , 70 parts

Temperature from 80 to 90 ⁰ C a 77% solution in this polyester with 30 parts of a commercially available

Isopropanol made; then it is treated with the liquid, methylated hexamethylolmelamine

"equivalent amount of dimethylaminoethanol. Furthermore, in order to ensure a better flow

sated. This polyester solution is obtained in such an amount, 2% of a commercially available leveling agent

a commercially available water-soluble, methyl-added 50.

etherified hexamethylolmelamine mixed in that a die - after adding 0.5 percent by weight of p-To-

Polyester / aminoplast ratio of 75:25 obtained from luenesulfonic acid (based on the binder) - from

will. Then this solution is prepared with water on this paint and 30 minutes at

a solids content of 55 weight percent of comparable 13O ⁰ C stoved Lacknlme are shiny and

thins. 55 have a hardness of 182 see and can be deep drawn

The - after the addition of 0.5 weight percent p-To- of 8.2 mm and an impact depression of > 5 min .

Claims (9)

Patent claims: 1. Liquid coating agents based on a mixture of binding agents and organic ones Solvents or water and the binder water-solubilizing additives or optionally Also on a solvent-free basis, which acts as a binder A) 50 to 10 percent by weight aminoplasts and / or their low molecular weight, defined precursors and B) 50 to 90 percent by weight of hydroxyl-containing and carboxyl-containing polyesters from aliphatic polyols, ethylene glycol and optionally other diols on the one hand as well as aromatic and aliphatic dicarboxylic acids on the other hand optionally contain in addition to customary auxiliaries, the binder also by co-condensation of aminoplasts and / or their low molecular weight, defined precursors with the Polyesters or by co-condensation of the starting products of the aminoplast production with the polyesters may have been produced, characterized in that polyester with average molecular weights between 600 and 3000 are used, which are produced by esterification Mixtures I and III have been prepared, Mixture I 1.1 to 1 to 33 mol percent of one or more aliphatic polyols with 3 or 4 hydroxyl groups and 3 to 6 carbon atoms and 1.2 to 99 to 67 mol percent from a mixture II of aliphatic and optionally cycloaliiphatic Diols consists, in turn II. I to more than 70 to 100 mole percent Ethylene glycol and II. 2 to less than 30 to 0 Molpro2: ent of one or more other aliphatic or cycloaliphatic diols in which the hydroxyl functions have 2 to 8 carbon atoms are separated and optionally up to 2 of the carbon atoms by oxygen atoms can be replaced, which in turn by at least 2 carbon atoms from each other should be separated consists, and mixture III III. 1 to 91 to 33 mole percent of one or more aromatic or cycloaliphatic Dicarboxylic acids and / or their derivatives and III.2 to 9 to 67 mol percent from one or more aliphatic dicarboxylic acids with 4 up to 12 carbon atoms and / or their derivatives consists. 2. Coating agent according to claim 1, characterized in that polyesters with average molecular weights between 800 and 2500 can be used. 3. Coating agent according to claim 1 and 2, da- characterized in that polyester with average ^ molar weights between 1000 and 2000 used will. 4. Coating agent according to claims 1 to 3, as indicated by · in that polyesters are eingesetzi, for their preparation as a component. \ _"T glycerol has been used. 5. Coating agent according to claim 1 to 4, characterized in that polyesters are used, for their production as component J M. 2 saturated, aliphatic dicarboxylic acids having A to 6 carbon atoms and / or their derivatives have been used. 6. Coating agent according to claim 1 to 5, characterized in that polyester eingetzi are used to manufacture them as a component 111.1 only phthalic anhydride is used has been. 7. Coating agent according to claim 1 to 6, characterized in that polyester eingetzi are used to manufacture them as a component 111.2 only adipic acid is used is. 8. Coating agent according to claim 1 to 7, characterized in that polyester eirgesetzl for the production of which only ethylene glycol was used as mixture II, 9. Coating agent according to claim 1 to 7, characterized in that polyester eingetzi are, for the production of which only propanediol (1,2) was used as component 11.2 is.