CATALYST SYSTEM FOR URETDIONE DISPERSIONS

Abstract

The present invention relates to a catalyst system comprising: A) at least one compound selected from azoles, oxazoles, thiazoles, benzotriazole, benzimidazole, benzoxazole and salts thereof; B) at least one acid catcher, which contains at least one epoxy group; and C) at least one catalyst containing an N,N,N-trisubstituted amidine structure with an amidine group content of from 12.0 to 47.0 wt %, calculated as CN2 with molecular weight=40. The invention also relates to a kit which comprises the catalyst system of the present invention and an aqueous uretdione dispersion having an acid number of from 1 to 100 KOH/g and additionally at least one carboxyl group. The invention further relates to a method for producing a polyurethane layer using the catalyst system of the present invention and said uretdione dispersion, and to the obtained polyurethane layer, and to the use of the catalyst system for curing aqueous acidic uretdione dispersions and/or for the production of paints or coatings.

Claims

1: A catalyst system comprising A) at least one compound selected from the group consisting of azoles, oxazoles, thiazoles, benzotriazole, benzimidazole, benzoxazole, and salts thereof; B) at least one acid scavenger containing at least one epoxy group; and C) at least one catalyst containing an N,N,N-trisubstituted amidine structure and having an amidine group content of 12.0 to 47.0% by weight calculated as CN2 with molecular weight=40.

2: The catalyst system as claimed in claim 1, wherein the at least one compound A) is selected from pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, and salts thereof.

3: The catalyst system as claimed in claim 1, wherein the at least one acid scavenger B) is selected from aliphatic or aromatic alcohols, diols, polyols, ethers and acids containing at least one epoxy group.

4: The catalyst system as claimed in claim 1, wherein the at least one catalyst containing an N,N,N-trisubstituted amidine structure and having an amidine group content of 12.0 to 47.0% by weight calculated as CN2, molecular weight=40, C) is selected from optionally substituted amidine bases bearing alkyl, aralkyl or allyl radicals, wherein the CN double bond of the amidine structure is both part of an open-chain molecule and an element of a cyclic or bicyclic system, or else may be positioned exocyclically on a ring system, or any desired mixtures of such amidines.

5: The catalyst system as claimed in claim 1, wherein A) and B) are present in a mass ratio of 1:1 to 10:1 and/or A) and C) are present in a mass ratio of 0.5:1 to 5:1 and/or B) and C) are present in a mass ratio of 1:1 to 1:10.

6: A kit comprising the catalyst system as claimed in claim 1 and an aqueous uretdione dispersion wherein the dispersion has an acid value of 1 to 100 mg KOH/g and at least one carboxyl group.

7: The kit as claimed in claim 6, wherein the equivalents ratio of uretdione to hydroxy groups is 0.5:1 to 1:0.5.

8: A process for producing a polyurethane layer comprising the steps of i) providing an aqueous uretdione dispersion having an acid value of 1 to 100 mg KOH/g and having at least one carboxyl group; ii) adding the catalyst system as claimed in claim 1 to produce a mixture; iii) applying the mixture obtained in ii to a substrate); iv) drying the mixture from step iii), and v) curing the mixture from step iv) by heating to 120 C. for up to 180 minutes.

9: A polyurethane layer, obtained by the process as claimed in claim 8.

10: In a process for curing aqueous uretdione dispersions having an acid value of 1 to 100 mg KOH/g and having at least one carboxyl group, or for producing paints or coatings the improvement comprising including the catalyst system as claimed in claim 1.

Description

EXAMPLES

Methods and Materials:

Methods:

[0121] Unless stated otherwise, all analytical methods relate to measurements at temperatures of 23 C.

Pendulum Hardness:

[0122] Pendulum hardness was measured on a glass plate in accordance with DIN EN ISO 1522:2007-04 and is determined by the Konig method.

Resistance to Solvents and Water:

[0123] The resistance of the cured paints to xylene, 1-methoxy-2-propyl acetate, ethyl acetate, acetone, and water was tested. A piece of absorbent cotton soaked in the test substance was laid on the coating surface and covered with a watch glass. After the specified exposure time, the cotton was removed and the exposed area was dried and examined immediately. The softening or discoloration of the coating surface was evaluated in accordance with DIN EN ISO 4628-1:2016-07. [0124] 0 unchanged, i.e. no noticeable change [0125] 1 very slight, i.e. only visible change, for example minor change in hue [0126] 2 detectable, i.e. clearly perceptible change, for example softening discernible by fingernail [0127] 3 clearly noticeable change, for example moderate change in hue, possible slight blistering [0128] 4 major change, for example severe blistering [0129] 5 coating completely destroyed without any external contact

IR Measurement:

[0130] The opening of the uretdione ring was characterized by a Bruker FT-IR spectrometer (Tensor II with platinum ATR module (diamond crystal)). The spectra were recorded in a wavenumber range of 4000-400 cm. The maximum of the uretdione peak (about 1760 cm) was evaluated. Peak heights relative to comparison systems were compared at a baseline value set at 100% (uretdione film without catalyst, dried at room temperature). The uretdione peak height of the films cured for 30 min at 180 C. was set at 0%. Variations were determined relative to these 100 and 0% values (ratio calculation).

[0131] For measurements on an ATR crystal, the intensity of the spectrum depends on the coverage of the crystal surface. Since it is not possible for the sample preparation to ensure comparable coverage of the crystal surface for comparable measurements, it is necessary for the ratio calculation to correct for this effect by normalizing all spectra to the peak for the CH stretching vibration (wavenumber range) (3000-2800 cm). The evaluation of the peak heights as described above includes an additional basic correction of the spectra.

[0132] The solids content (non-volatile content) was determined by heating a weighed sample to constant weight at 125 C. On reaching constant weight, the solids content is calculated by reweighing the sample.

[0133] The NCO content was determined volumetrically in accordance with DIN-EN ISO 11909. The check for free NCO groups was carried out by IR spectroscopy (band at 2260 cm).

[0134] The reported viscosities were determined by rotary viscometry in accordance with DIN 53019:2016-10 at 23 C. using a rotary viscometer at a shear rate of 40 1/s, Anton Paar Germany GmbH, Ostfildern, Germany.

[0135] The mean particle sizes (the number average is reported) of the polyurethane dispersions were determined by laser correlation spectroscopy (instrument: Malvern Zetasizer 1000, Malvern Inst. Limited, London, UK) after diluting with deionized water.

[0136] The zeta potential was measured by diluting a drop of the sample with 20 ml of demineralized water and homogenizing by stirring. The zeta potential was then determined in the Malvern Nanosizer ZS90 (Malvern Instruments, Herrenberg, Germany) at 23 C.

[0137] The acid value of the particular dispersion was determined in accordance with DIN EN ISO 2114: 2002-06. Instead of a mixture of toluene and ethanol as described in DIN EN ISO 2114: 2002-06, the solvent used was a mixture of acetone and ethanol (2:1 by weight). The units for the acid number are mg KOH per g of the analyzed sample.

Materials:

[0138] Lupragen N 700 (1,8-diazabicyclo[5.4.0]undecene-7 (DBU)): from BASF SE
Sodium 1,2,4-triazolate: from Sigma Aldrich
Heloxy modifier TP: polyfunctional glycidyl ether of trimethylolpropane, from Hexion
Bayhydrol A2695: water-dilutable, OH-functional polyacrylate dispersion; approx. 41% in water/1-butoxy-2-propanol, neutralized with triethanolamine/dimethylethanolamine, 7.2% 1-butoxy-2-propanol, from Covestro
Dowanol PnB: propylene glycol mono-n-butyl ether, from Dow
Peroxan DB: di-tert-butyl peroxide: from Pergan
Solvent Naphtha 100: an aromatic solvent, from Azelis
Butylglycol: from Brenntag
Dimethylolpropionic acid (DMPA): from Perstorp
Addocat SO: tin(II) 2-ethylhexanoate, from Rhein Chemie,
All acrylate monomers and amines (from Sigma-Aldrich) were used as supplied.
Veova 9: Versatic acid vinyl ester, from Momentive
Other solvents and chemicals: Sigma-Aldrich
Xylene (Xy); 1-methoxy-2-propyl acetate (MPA); ethyl acetate (EA); acetone (Ac)

POLYMER SYNTHESIS EXAMPLES

Preparation Example 1

Preparation of a Uretdione Polyisocyanate Based on Isophorone Diisocyanate

[0139] To 1000 g (4.50 mol) of isophorone diisocyanate (IPDI) were successively added at room temperature under dry nitrogen, and with stirring, 10 g (1%) of triisodecyl phosphite and 20 g (2%) of 4-dimethylaminopyridine (DMAP) as catalyst. After 20 h, the reaction mixture, which had an NCO content of 28.7%, corresponding to a degree of oligomerization of 21.8%, was freed of volatiles, without prior addition of a catalyst poison, with the aid of a thin-film evaporator at a temperature of 160 C. and a pressure of 0.3 mbar.

[0140] This yielded a bright yellow uretdione polyisocyanate having a free NCO group content of 17.0%, a monomeric IPDI content of 0.4%, and a viscosity (in accordance with DIN EN ISO 3219:1994-10) of more than 200 000 mPas (23 C.).

Preparation of a Water-Emulsifiable Uretdione Group-Containing Crosslinker

[0141] 247 g (1.00 equiv.) of the above-described uretdione group-containing polyisocyanate, based on IPDI and having a free isocyanate group content of 17.0% and a calculated uretdione group content of 20.8%, was introduced into 370.3 g of 1-methoxy-2-propyl acetate, mixed with 0.2 g of dibutyltin dilaurate (DBTL) as catalyst, and heated to 80 C. under dry nitrogen. A mixture of 40.6 g (0.90 equiv.) of 1,4-butanediol and 82.5 g (0.11 equiv.) of methoxypolyethylene glycol 750 was then added over a period of 30 minutes and the mixture was stirred at a reaction temperature of max. 105 C. until the NCO content of the reaction mixture had fallen to below 0.1% after about 6 h [0142] This resulted in a pale yellow solution of a uretdione group-containing crosslinker having the following properties:
NCO content: <0.1%
Content of uretdione groups (calc.): 6.9%

Monomeric IPDI: 0.09%

[0143] Solids content: 50%

Preparation Example 1a

[0144] 337 g of 1,4-butanediol, 108 of 2-ethylhexanol, and 569 of e-caprolactone were mixed at room temperature under dry nitrogen, 0.3 g of tin(II) octoate was added, and the mixture was stirred at 160 C. for 5 h and then cooled to room temperature. To this mixture was then added, over a period of 30 min, 1850 g of the polyisocyanate from preparation example 1 warmed to 80 C., which was based on IPDI and had a free isocyanate group content of 17.0% and a calculated uretdione group content of 20.8%. The reaction mixture was stirred at a temperature of max. 100 C. until the NCO content of the reaction mixture had fallen to a value of 0.8% after 7 to 8 h. 1910 g of Dowanol PnB was then added to the reaction mixture and the solution was cooled to room temperature.

Preparation Example 2

Preparation of an Anionic Uretdione Prepolymer Dispersion:

[0145] 218.5 g of IPDI dimer from preparation example 1 was dissolved in 850 g of acetone at 50 C. in a standard stirring apparatus. 22.9 g of dimethylolpropionic acid, 265.9 g of an OH-functional polyester based on 3039 g of adipic acid, 4041 g of isophthalic acid, 267 g of 1,2-propylene glycol, 4773 g of neopentyl glycol, and 1419 g of trimethylolpropane (OH value of the polyester: 181 mg KOH/g) and 0.63 g of tin neodecanoate were added and the mixture was stirred under reflux at atmospheric pressure until the NCO content had fallen to below 0.5%. This was followed by the addition of 16.8 g of N,N-dimethylaminoethanol and 927 g of water. The acetone was removed by distillation under reduced pressure and the viscosity adjusted by adding water.

The resulting white dispersion had the following properties:
Solids content: 37.6%
Mean particle size: 91 nm
Viscosity: 31 mPas
Acid value: 7.3 mg KOH/g (based on the dispersion)
Zeta potential: 49.6 mV

Preparation Examples 3a-d

Preparation Example 3a

[0146]

TABLE-US-00001 TABLE 1 Weight (g) Component 1 DOWANOL PnB 1567 Component 2 PEROXAN DB 33 DOWANOL PnB 33 Component 3 METHYL METHACRYLATE 1243 HYDROXYETHYL METHACRYLATE 2419 n-BUTYL METHACRYLATE 592 n-BUTYL ACRYLATE 723 ISOBORNYL METHACRYLATE 1701 BUTANEDIOL MONOACRYLATE 836 STYRENE 573 Component 4 PEROXAN DB 140 DOWANOL PnB 140 Component 5 BUTANEDIOL MONOACRYLATE 296 METHYL METHACRYLATE 449 HYDROXYETHYL METHACRYLATE 467 n-BUTYL ACRYLATE 379 ACRYLIC ACID 316 Component 6 PEROXAN DB 33 DOWANOL PnB 60 Total amount 12000

[0147] Component 1 from table 1 was weighed into a stirring apparatus under nitrogen and heated to 138 C. Component 2 was then metered in uniformly at 138 C. over a period of 20 minutes. After this, component 3 and component 4 were immediately metered in uniformly at 138 C. in parallel over a period of 4 h 30 min. At the end of the addition, the reaction mixture was held at 138 C. for 30 min. Finally, component 5 and component 6 were metered in uniformly at 138 C. in parallel over a period of 1 h 30 min. At the end of the addition, the reaction mixture was held at 138 C. for a further 1 h. The reaction mixture was cooled to 100 C. and then transferred. A slightly yellowish, highly viscous polyacrylate solution was obtained.

[0148] 500 g of this solution was weighed into a stirring apparatus under nitrogen and heated to 70 C. After homogenizing, 567 g of the solution from preparation example 1a was added and the mixture was homogenized again at 70 C. for 30 min, followed by addition of a mixture of 21.5 g of triethanolamine and 4.3 g of dimethylethanolamine. The mixture was stirred at 70 C. for a further 30 min and then 463 g of distilled water was stirred in to the mixture. Fine adjustment of the viscosity to approx. 2000 mPas afforded a dispersion having the following properties:

Solids content: 43.7% by weight
Acid value (100%): 13 mg KOH/g
OH content (100%, calculated): 2.8% by weight
Mean particle size: 230 nm
Viscosity: 2030 mPas

Preparation Example 3b

[0149] 500 g of polyacrylate solution from preparation example 1 was weighed into a stirring apparatus under nitrogen and heated to 70 C. After homogenizing, 283 g of the solution from preparation example 1a was added and the mixture was homogenized again at 70 C. for 30 min, followed by addition of a mixture of 21.5 g of triethanolamine and 4.3 g of dimethylethanolamine. The mixture was stirred at 70 C. for a further 30 min and then 407 g of distilled water was stirred in. Fine adjustment of the viscosity to approx. 2000 mPas afforded a dispersion having the following properties:

Solids content: 41.7% by weight
Acid value (100%): 16.6 mg KOH/g
OH content (100%, calculated): 3.6% by weight
Mean particle size: 175 nm
Viscosity: 2360 mPas

Preparation Example 3c

[0150]

TABLE-US-00002 TABLE 2 Weight (g) Component 1 SOLVENT NAPHTHA 100 900 BUTYLGLYCOL 648 Component 2 PEROXAN DB 33 BUTYLGLYCOL 33 Component 3 METHYL METHACRYLATE 3669 HYDROXYETHYL METHACRYLATE 1816 n-BUTYL ACRYLATE 2603 Component 4 PEROXAN DB 139 BUTYLGLYCOL 139 Component 5 METHYL METHACRYLATE 520 HYDROXYETHYL METHACRYLATE 734 n-BUTYL ACRYLATE 408 ACRYLIC ACID 245 Component 6 PEROXAN DB 33 BUTYLGLYCOL 80 Total amount 12000

[0151] Component 1 from table 2 was weighed into a stirring apparatus under nitrogen and heated to 138 C. Component 2 was then metered in uniformly at 138 C. over a period of 20 minutes. After this, component 3 and component 4 were immediately metered in uniformly at 138 C. in parallel over a period of 4 h 30 min. At the end of the addition, the reaction mixture was held at 138 C. for 30 min. Finally, component 5 and component 6 were metered in uniformly at 138 C. in parallel over a period of 1 h 30 min. At the end of the addition, the reaction mixture was held at 138 C. for a further 1 h. The reaction mixture was cooled to 110 C. and then transferred. A pale yellowish, highly viscous polyacrylate solution was obtained.

[0152] 552 g of this solution was weighed into a stirring apparatus under nitrogen and heated to 70 C. After homogenizing, 471 g of the solution from preparation example 1a was added and the mixture was homogenized again at 70 C. for 30 min, followed by addition of 14.6 g of dimethylethanolamine. The mixture was stirred at 70 C. for a further 30 min and then 466 g of distilled water was stirred in. Fine adjustment of the viscosity to approx. 2000 mPas afforded a dispersion having the following properties:

Solids content: 46.1% by weight
Acid value (100%): 16.3 mg KOH/g
OH content (100%, calculated): 2.1% by weight
Mean particle size: 225 nm
Viscosity: 1110 mPas

Preparation Example 3d

[0153]

TABLE-US-00003 TABLE 3 Weight (g) Component 1 DOWANOL PnB 3438 Component 2 PEROXAN DB 33 DOWANOL PnB 33 Component 3 STYRENE 570 METHYL METHACRYLATE 1566 HYDROXYETHYL METHACRYLATE 1601 n-BUTYL ACRYLATE 341 ISOBORNYL METHACRYLATE 1520 n-BUTYL METHACRYLATE 1208 VEOVA 9 1251 Component 4 PEROXAN DB 118 DOWANOL PnB 321 Total amount 12000

[0154] Component 1 from table 3 was weighed into a stirring apparatus under nitrogen and heated to 148 C. Component 2 was then metered in uniformly at 128 C. over a period of 20 minutes. After this, component 3 and component 4 were immediately metered in uniformly at 148 C. in parallel over a period of 6 h. At the end of the addition, the reaction mixture was held at 148 C. for 60 min. At the end of the addition, the reaction mixture was held at 148 C. for a further 1 h. The polyacrylate solution was cooled to 80 C. and then transferred.

TABLE-US-00004 TABLE 4 Raw material Weights Component 1 Polyacrylate solution from table 3 1993 Component 2 PEROXAN DB 36 DOWANOL PnB 36 72 Component 3 2 - ETHYLHEXYL ACRYLATE 377 HYDROXYETHYL ACRYLATE 1931 n-BUTYL METHACRYLATE 1308 ISOBORNYL METHACRYLATE 2951 n-BUTYL ACRYLATE 338 BUTANEDIOL MONOACRYLATE 555 Component 4 PEROXAN DB 129 DOWANOL PnB 154 Component 5 METHYL METHACRYLATE 533 HYDROXYETHYL ACRYLATE 799 n-BUTYL ACRYLATE 411 METHACRYLIC ACID 333 Component 6 PEROXAN DB 36 DOWANOL PnB 80 Total amount 12000

[0155] Component 1 from table 4 was weighed into a stirring apparatus under nitrogen and heated to 144 C. Component 2 was then metered in uniformly at 144 C. over a period of 20 minutes. After this, component 3 and component 4 were immediately metered in uniformly at 144 C. in parallel over a period of 4 h 30 min. At the end of the addition, the reaction mixture was held at 144 C. for 5 min. Finally, component 5 and component 6 were metered in uniformly at 144 C. in parallel over a period of 1 h 30 min. At the end of the addition, the reaction mixture was held at 144 C. for a further 1 h. The reaction mixture was cooled to 100 C. and then transferred. A pale yellowish, highly viscous polyacrylate solution was obtained.

[0156] 304 g of this solution was weighed into a stirring apparatus under nitrogen and heated to 70 C. After homogenizing, 385 g of the solution from preparation example 1a was added and the mixture was homogenized again at 70 C. for 30 min, followed by addition of 11 g of dimethylethanolamine. The mixture was stirred at 70 C. for a further 30 min and then 324 g of distilled water was stirred into the mixture. Fine adjustment of the viscosity to approx. 2000 mPas afforded a dispersion having the following properties:

Solids content: 42.6% by weight
Acid value (100%): 18 mg KOH/g
OH content (100%, calculated): 2.5% by weight
Mean particle size: 287 nm
Viscosity: 2030 mPas

Paint Tests:

[0157] Paint Tests on Example Dispersion 1 from Preparation Example 1:

[0158] Clearcoats were produced from the following composition:

[0159] The uretdione dispersion from preparation example 1 was dispersed in water and then mixed with Bayhydrol A2695 in a SpeedMixer (2000 rpm). Heloxy modifier TP was added, followed by addition of sodium 1,2,4-triazolate (10% in water) and DBU (10% in water, freshly mixed). The mixture was mixed again with a SpeedMixer (2000 rpm) and left to stand on the laboratory benchtop for 30 min to reduce frothing.

[0160] The mixture was applied to a glass plate or standardized coil test plate (coil coating blackCS 200570, from Heinz Zanders Prf-Blech-Logistik) in a layer thickness of 150-180 m (wet) using a coating bar. The plates were dried at room temperature for 5 minutes and then oven baked at 100 C. for 30 minutes. The performance of the resulting films was evaluated and an IR spectrum was recorded.

Example 4: Formulations and Comparative Formulations Using Example Dispersion 1

[0161]

TABLE-US-00005 SC (%) C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 11 Bayhydrol A 42.90 20.0 20 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 2695 Dispersion 50.00 28.5 28.5 28.5 28.5 28.5 28.5 28.5 28.5 28.5 preparation example 1 in MPA Demineralized 10 34.4 34.4 34.4 34.4 34.4 34.4 34.4 34.4 34.4 water Heloxy 100.00 0.49 0.49 0.49 0.49 0.49 modifier TP 1,2,4- 10.00 2.30 2.30 2.30 2.30 Triazole-Na in water Lupragen 10.00 2.30 2.30 2.30 2.30 N700 (DBU) in water C = comparative example, non-inventive SC = solids content in %
Performance Tests/Physical Properties of the Paints from Example 4:

TABLE-US-00006 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 11 Ring >97 >97 >97 >97 >97 12 >94 94 <4 opening.sup.1 Knig 98 110 128 170 189 181 156 198 181 171 195 pendulum hardness (sec) Resistances.sup.2 0-5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 1/1/2/2 3/3/4/5 3/3/3/3 0/0/0/1 Resistances.sup.3 0-5 4-5 4-5 4 4 4 4 4 4 4 4 1-2 C = comparative example, non-inventive Curing conditions unless explicitly stated otherwise are 30 min at 100 C. .sup.1 = IR intensity of uretdione peak having peak max. between 1750 and 1800 cm.sup.1 in % .sup.2 = versus Xy/MPA/EA/Ac, applied to sheet metal for 5 minutes .sup.3 = versus water, applied to glass for 1 hour

Paint Tests on Example Dispersion 2:

[0162] Clearcoats were produced from the following composition:

[0163] Heloxy modifier TP, sodium 1,2,4-triazolate (10% in water), and DBU (10% in water, freshly mixed) were added to the uretdione dispersion from preparation example 2 and the resulting mixture was mixed in a SpeedMixer (2000 rpm) and then left to stand for 30 min to reduce frothing.

[0164] The mixture was applied to a glass or sheet metal in a layer thickness of 150-180 m (wet) using a coating bar. The plates were dried at room temperature for 5 minutes and then oven baked at 100 C. for 30 minutes. The performance of the resulting paints was evaluated and an IR spectrum was recorded.

Example 5: Comparative Tests and Tests with Formulations Using Example Dispersion 2

[0165]

TABLE-US-00007 SC C1 C2 C3 C4 C5 C6 7 Dispersion from 31.00% 20.00 20.00 20.00 20.00 20.00 20.00 20.00 preparation example 2 Triazole-Na in 10.00% 1.20 1.20 1.20 water DBU in water 10.00% 0.62 0.62 0.62 0.62 Heloxy modifier TP 0.38 0.38 0.38 C = comparative example, non-inventive SC = solids content (%)
Performance Tests/Physical Properties of the Paint from Example 5:

TABLE-US-00008 C1 C2 C3 C4 C5 C6 7 Ring opening.sup.1 >97 >97 >97 87 80 31 <3 Knig pendulum 216 215 217 198 213 220 226 hardness (sec) Resistances.sup.2 0-5 5/5/5/5 5/5/5/5 5/5/5/5 3/3/4/4 5/5/5/5 1-2/3/3-4 1/1/2/4 Resistances.sup.3 0-5 0 1-2 1 1 1 0 0 C = comparative example, non-inventive Curing conditions unless explicitly stated otherwise are 30 min at 100 C. .sup.1 = IR intensity of uretdione peak having peak max. between 1750 and 1800 cm.sup.1 in % .sup.2 = versus Xy/MPA/EA/Ac, applied to sheet metal for 5 minutes .sup.3 = versus water, applied to glass for 1 hour
Paint Tests on Dispersions from Preparation Examples 3a-d:

[0166] Clearcoats were produced from the following composition:

[0167] The uretdione dispersion from preparation examples 3a-d was in a SpeedMixer (2000 rpm) with the uretdione dispersion from preparation example 1, Heloxy modifier TP, sodium 1,2,4-triazolate (10% in water) and DBU (10% in water, freshly mixed). The mixture was left to stand for 30 min to reduce frothing.

[0168] The mixture was applied to a glass or sheet metal in a layer thickness of 150-180 m (wet) using a coating bar. The plates were dried at room temperature for 5 minutes and then oven baked at 100 C. for 30 minutes. The performance of the resulting coatings was evaluated and an IR spectrum was recorded.

Example 6: Comparative Tests and Tests with Formulations from Preparation Examples 3a-d

[0169]

TABLE-US-00009 SC C1 C2 C3 C4 C5 C6 C7 C8 9 10 11 12 13 14 15 16 3a 41.7% 10.0 30.0 20.0 30.0 3b 43.7% 10.0 30.0 20.0 30.0 3c 46.1% 10.0 30.0 20.0 30.0 3d 42.6% 10.0 30.0 20.0 30.0 1 50.0% 31.3 25.5 20.2 22.2 31.3 25.5 20.2 22.2 Demineralized 36.0 32.0 25.0 30.0 2.0 2.0 2.00 2.00 34.00 33.00 28.00 29.00 water Heloxy 100.0% 0.36 0.30 0.39 0.40 0.54 0.45 0.59 0.60 modifier TP 1,2,4- 10.0% 0.83 0.87 0.92 0.85 2.80 2.60 2.30 2.50 Triazole-Na in water Lupragen 10.0% 0.83 0.87 0.92 0.85 2.80 2.60 2.30 2.50 N700 (DBU) in water Crosslinking 0.22 0.44 0.5 0.5 1.0 1.0 1.0 1.0 0.22 0.44 0.5 0.5 1.0 1.0 1.0 1.0 ratio C = comparative examples SC = solids content (%)
Performance Tests/Physical Properties of the Paints from Example 6:

TABLE-US-00010 C1 C2 C3 C4 C5 C6 C7 C8 Ring opening.sup.1 >97 >97 >97 >97 >97 >97 >97 93 Knig pendulum 61 93 55 80 131 152 114 129 hardness (sec) Resistances.sup.2 0-5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 5/5/5/5 Resistances.sup.3 0-5 4 4 3 3 2 2 1 1 C = comparative example, non-inventive Curing conditions unless explicitly stated otherwise are 30 min at 100 C. .sup.1 = IR intensity of uretdione peak having peak max. between 1750 and 1800 cm.sup.1 in % .sup.2 = versus Xy/MPA/EA/Ac, applied to sheet metal for 5 minutes .sup.3 = versus water, applied to glass for 1 hour

TABLE-US-00011 9 10 11 12 13 14 15 16 Ring opening.sup.1 <3 <3 <3 <3 <3 <3 <3 <3 Knig pendulum 126 97 115 155 167 194 189 189 hardness (sec) Resistances.sup.2 0-5 3/4/4/5 2/3/3/4 2/4/4/4 3/4/4/4 1/1/1/1 0/0/1/1 0/1/1/4 0/0/2/4 Resistances.sup.3 0-5 3-4 4 2 2 1 1-2 1-2 1 C = comparative example, non-inventive Curing conditions unless explicitly stated otherwise are 30 min at 100 C. .sup.1 = IR intensity of uretdione peak having peak max. between 1750 and 1800 cm.sup.1 in % .sup.2 = versus Xy/MPA/EA/Ac, applied to sheet metal for 5 minutes .sup.3 = versus water, applied to glass for 1 hour

[0170] The curing reaction can be monitored by monitoring the opening of the uretdione ring by IR spectroscopy. With the combination of sodium triazolate, DBU and Heloxy modifier TP, the IR peak for uretdione has almost disappeared (<4% based on the height of the uretdione peak of the dried starting material). The pendulum hardness also increases with the efficacy of the catalyst mixture. Resistance to xylene, MPA, EA, and acetone needs to be at least 1/1/2/4; water resistance must be at least 1-2. Both resistances can be achieved only through the catalyst mixture. In example 6 it can be seen that an equimolar amount of uretdione to alcohol (entries 13 to 16) results in much higher hardness values and better resistances than an excess of alcohol (entries 9 to 12).