METHOD FOR PRODUCING AND USING AQUEOUS POLYURETHANE DISPERSIONS AND USE OF SAME IN COATING AGENTS

Abstract

The present invention relates to the use of aqueous hybrid dispersions, wherein (a) an aqueous polyurethane dispersion is prepared and (b) said polyurethane dispersion is used as raw material for the additional synthesis of a polyacrylate dispersion and the resulting hybrid dispersion is used as binder in filled coating materials, in particular, as binder for the flexible roof coating.

Claims

1-8. (canceled)

9. A binder, comprising: an aqueous polyurethane dispersion comprising a polyalkylene oxide content of at least 10 g/kg of polyurethane; and a sulfonated raw material content of at least 25 mmol per kg of polyurethane.

10. The binder according to claim 9, wherein said aqueous polyurethane dispersion comprises a long-chain alkanol-based polyethylene oxide and a sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid.

11. A filled coating material, comprising: the binder according to claim 9.

12. A flexible roof coating, comprising: the binder according to claim 9.

13. An architectural paint, comprising: the binder according to claim 9.

14. A coating composition, comprising: an aqueous polyurethane dispersion comprising a polyalkylene oxide content of at least 10 g/kg of polyurethane; and a sulfonated raw material content of at least 25 mmol per kg of polyurethane; optionally at least one (in)organic filler and/or at least one (in)organic pigment; optionally at least one customary assistant; and water.

15. The coating composition according to claim 14, wherein said aqueous polyurethane dispersion comprises a long-chain alkanol-based polyethylene oxide and a sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid.

16. A flexible roof coating, comprising: the coating composition according to claim 14.

17. An architectural paint, comprising: the coating composition according to claim 14.

18. A coated surface, of which at least a portion is covered with an aqueous polyurethane dispersion, said dispersion comprising a polyalkylene oxide content of at least 10 g/kg of polyurethane; and a sulfonated raw material content of at least 25 mmol per kg of polyurethane.

19. A building material substrate, comprising: a main surface of which at least a portion is covered with an aqueous polyurethane dispersion comprising a polyalkylene oxide content of at least 10 g/kg of polyurethane; and a sulfonated raw material content of at least 25 mmol per kg of polyurethane.

20. An outer flexible roof coating composition, comprising: an aqueous polyurethane dispersion comprising a polyalkylene oxide content of at least 10 g/kg of polyurethane; and a sulfonated raw material content of at least 25 mmol per kg of polyurethane.

Description

EXAMPLE 1

[0112] 456.05 g of a polyesterdiol of adipic acid, neopentyl glycol and 1,6-hexanediol having an OH number of 56, [0113] 39.69 g of a butanol-based polyethylene oxide having an OH number of 15 and [0114] 0.1932 g of dibutyltin dilaurate were initially charged in a stirred flask and heated to 60° C. To this were added dropwise 132.05 g of 4,4′-diisocyanatodicyclohexylmethane and 67.69 g (0.3185 mol) of isophorone diisocyanate over 5 minutes. The resulting mixture was diluted with 117.20 g of acetone and stirred for 1 hour at 74° C. Subsequently, 20.30 g of 1,4-butanediol were added rapidly and the mixture was further stirred at 74° C. After 2 hours, the mixture was diluted with 500.98 g of acetone and cooled down to 50° C. The NCO content was determined as 1.01 wt % (calculated: 1.00 wt %).

[0115] 30.81 g of a 50% aqueous solution of the sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 743.47 g of water over 24 minutes at 50° C. and then chain-extended with 4.21 g of diethylenetriamine and 2.06 g of isophoronediamine in 36.92 g of water.

[0116] After distillation of the acetone, a finely divided dispersion having a solids content of about 45%, a particle size of 91.7 nm and a pH of 9.46 was comprised.

COMPARATIVE EXAMPLE 1

[0117] 456.05 g of a polyesterdiol of adipic acid, neopentyl glycol and 1,6-hexanediol having an OH number of 56, [0118] 39.69 g of a butanol-based polyethylene oxide having an OH number of 15 and [0119] 0.1932 g of dibutyltin dilaurate were initially charged in a stirred flask and heated to 60° C. To this were added dropwise 132.05 g of 4,4′-diisocyanatodicyclohexylmethane and 67.69 g (0.3185 mol) of isophorone diisocyanate over 5 minutes. The resulting mixture was diluted with 117.20 g of acetone and stirred for 1 hour at 74° C. Subsequently, 20.30 g of 1,4-butanediol were added rapidly and the mixture was further stirred at 74° C. After 2 hours, the mixture was diluted with 500.98 g of acetone and cooled down to 50° C. The NCO content was determined as 1.01 wt % (calculated: 1.00 wt %).

[0120] 24.97 g of a 50% aqueous solution of the sodium salt of the Michael adduct of ethylene diamine to acrylic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 743.47 g of water over 24 minutes at 50° C. and then chain-extended with 4.21 g of diethylenetriamine and 2.06 g of isophorone diamine in 36.92 g of water.

[0121] After distillation of the acetone, a finely divided dispersion having a solids content of about 45%, a particle size of 96.8 nm and a pH of 9.23 was comprised.

EXAMPLE 2

[0122] 352.2 g of a polyesterdiol of adipic acid, neopentyl glycol and 1,6-hexanediol having an OH number of 56,

[0123] 42.85 g of a butanol-based polyethylene oxide having an OH number of 15 and 0.26 g of a tin-free catalyst based on bismuth neodecanoate, 75% strength in acetone (Borchikat 315, OMG Borchers), were initially charged in a stirred flask and heated to 56° C. To this were added dropwise 72.83 g of 4,4′-diisocyanatodicyclohexylmethane and 61.3 g (0.3185 mol) of isophorone diisocyanate over 5 minutes. The resulting mixture was then diluted with 96.32 g of acetone and stirred for 1 hour and 15 minutes at 76° C. Subsequently, 18.39 g of 1,4-butanediol were added rapidly and the mixture was further stirred at 74° C. After 2 hours, the mixture was diluted with 413.41 g of acetone and cooled down to 50° C. The NCO content was determined as 1.27 wt % (calculated: 1.31 wt %).

[0124] 39.21 g of a 50% aqueous solution of the sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 664.15 g of water over 15 minutes at 50° C. and then chain-extended with 3.81 g of diethylenetriamine and 1.86 g of isophorone diamine in 36.92 g of water.

[0125] After distillation of the acetone, a finely divided dispersion having a solids content of about 40.8%, a particle size of 93 nm and a pH of 9.74 was comprised.

EXAMPLE 3

[0126] 81.94 g of 2-butyl-2-ethyl-1,3-propanediol, 39.69 g of a butanol-based polyethylene oxide having an OH number of 15, 258.76 g of PolyTHF 2000 and 0.4 g of tin-free catalyst based on bismuth neodecanoate, 75% strength in acetone (Borchikat 315, OMG Borchers), were initially charged in a stirred flask and heated to 56° C. To this were added dropwise 78.9 g of bis(4-isocyanotocyclohexyl)methane and 66.4 g of isophorone diisocyanate over 5 minutes. The resulting mixture was then diluted with 97 g of acetone and stirred for 2 hours and 35 minutes at 74° C. Subsequently, 19.9 g of 1,4-butanediol were added dropwise and the mixture was further stirred at 74° C. After 2 hours and 40 minutes, the mixture was diluted with 417 g of acetone and cooled down to 50° C. The NCO content was determined as 1.25 wt % (calculated: 1.18 wt %).

[0127] 30.3 g of a 50% aqueous solution of the sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 660.6 g of water over 15 minutes at 50° C. and then chain-extended with 4.12 g of diethylenetriamine and 2.02 g of isophorone diamine in 36.21 g of water.

[0128] After distillation of the acetone, a finely divided dispersion having a solids content of about 44.5%, a particle size of 91.8 nm and a pH of 8.03 was comprised.

EXAMPLE 4

[0129] 162.38 g of 2-butyl-2-ethyl-1,3-propanediol, 52.55 g of a butanol-based polyethylene oxide having an OH number of 15, 146.51 g of PolyTHF 2000 and 0.39 g of tin-free catalyst based on bismuth neodecanoate, 75% strength in acetone (Borchikat 315, OMG Borchers), were initially charged in a stirred flask and heated to 56° C. To this were added dropwise 89.32 g of bis(4-isocyanotocyclohexyl)methane and 75.17 g of isophorone diisocyanate over 5 minutes. The resulting mixture was then diluted with 95.74 g of acetone and stirred for 3 hours and 15 minutes at 76° C. Subsequently, 22.55 g of 1,4-butanediol were added dropwise and the mixture was further stirred at 77° C. After 1 hour, the mixture was diluted with 415 g of acetone and cooled down to 50° C. The NCO content was determined as 1.3 wt % (calculated: 1.35 wt %).

[0130] 34.35 g of a 50% aqueous solution of the sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 658.36 g of water over 15 minutes at 50° C. and then chain-extended with 4.67 g of diethylenetriamine and 2.28 g of isophorone diamine in 41 g of water.

[0131] After distillation of the acetone, a finely divided dispersion having a solids content of about 40.9%, a particle size of 85.8 nm and a pH of 9.78 was comprised.

EXAMPLE 5

[0132] 81.22 g of 2-butyl-2-ethyl-1,3-propanediol, 46 g of a butanol-based polyethylene oxide having an OH number of 15, 261.61 g of a polyesterpolyol based on hexanedioic acid and 2,2-dimethyl-1,3-propanediol and 1,6-hexanediol having an OH number of 56 and 0.27 g of tin-free catalyst based on bismuth neodecanoate, 75% strength in acetone (Borchikat 315, OMG Borchers), were initially charged in a stirred flask and heated to 57° C. To this were added dropwise 78.18 g of bis(4-isocyanotocyclohexyl)methane and 65.8 g of isophorone diisocyanate over 5 minutes. The resulting mixture was then diluted with 97 g of acetone and stirred for 3 hours and 30 minutes at 76° C. Subsequently, 19.74 g of 1,4-butanediol were added dropwise and the mixture was further stirred at 74° C. After 1 hour, the mixture was diluted with 417.4 g of acetone and cooled down to 50° C. The NCO content was determined as 1.15 wt % (calculated: 1.17 wt %).

[0133] 30.07 g of a 50% aqueous solution of the sodium salt of 2-aminoethyl-2-aminoethanesulfonic acid are added over 5 minutes at 50° C. and the mixture is further stirred for an additional 5 minutes. The mixture is then diluted with 660.76 g of water over 17 minutes at 50° C. and then chain-extended with 4.09 g of diethylenetriamine and 2 g of isophorone diamine in 35.89 g of water.

[0134] After distillation of the acetone, a finely divided dispersion having a solids content of about 42.1%, a particle size of 102.8 nm and a pH of 9.87 was comprised.

APPLICATIONS—RELATED TESTS

a) Preparation of the Paint Formulations

[0135] The constituents shown in table 1 (amounts in g) were used to prepare in the order shown from top to bottom, with stirring using a disc stirrer at 400-2500 revolutions per minute, the roof membrane formulations based on the exemplary aqueous polymer dispersions.

TABLE-US-00001 TABLE 1 Roof membrane formulation A A1 B C D E Dispersion example 1 Comp. 1 2 3 4 5 Dispersion amount [g] 62 62 58 63.5 63 65 Lutensol TO82 0.4 0.4 0.4 0.4 0.4 0.4 Agitan 282 0.5 0.5 0.5 0.5 0.5 0.5 Dispex CX 4320 1.2 1.2 1.2 1.2 1.2 1.2 Omyacarb 5GU 29 29 36.5 34 34 31.5 Water 6 6 3 0 0 0 Rheovis PU 1270 0.5 0.5 0.2 0.4 0.4 0.4 Agitan 282 0.4 0.4 0.4 0.4 0.4 0.4

Raw Materials Used

1) Lutensol TO 82, BASF SE, Ludwigshafen

2) Agitan 282, Münzing Chemie GmbH, Heilbronn

3) Dispex CX 4320, BASF SE, Ludwigshafen

4) Hydrocarb 95 ME, Omya, Oftringen, Switzerland

5) Omyacarb 5 GU, Omya, Oftringen, Switzerland

6) Omyacarb Extra CL, Omya, Oftringen, Switzerland

7) Rheovis PU 1270, BASF SE, Ludwigshafen

[0136] Once the last component had been added the mixture was further stirred until all components are homogeneously mixed (about 10 min) and the roof membrane formulation obtained is subsequently transferred into a DAC 400 FVZ Speed Mixer from Hauschild for 0.5 min at 2000 rpm. The roof membrane formulation has a solids content of about 63-67%, a pigment volume concentration of about 29 and a viscosity of 8000-10000 mPas (Brookfield, spindle 6, 20 rpm).

b) Preparation of the Coatings and Test Specimens

[0137] The abovementioned roof membrane formulation was applied to a teflon-coated substrate in a layer thickness of 1.2 mm with a knife coater. The coatings thus obtained were subsequently dried for 7 days in a conditioning chamber at 50% relative humidity and 23° C. The resulting dry layer thickness is about 0.60 mm. After removal of the coating from the substrate, the required test specimens were cut out with appropriate cutting dies.

c.) Tensile Strength, Breaking Strength and Elongation at Break Testing

[0138] Dumbells of size S1 were cut out of the coatings described hereinabove using a cutting die. Testing was carried out according to DIN 53504. The dumbells are clamped in a tensile/elongation tester from Zwick and subsequently pulled apart at a rate of 200 mm/min until they break.

TABLE-US-00002 TABLE 2 Testing of the roof membrane formulation Roof membrane formulation Comp. A 1 B C D E Maximum force N/mm.sup.2 4.41 3.2 4.09 3.64 4.48 5.09 Elongation at % 775 40 855 603 424 638 maximum strength Breaking strength N/mm.sup.2 4.37 3.15 4.08 3.63 4.47 5.09 Elongation at break % 785 42 856 604 425 638

[0139] All coating formulations A to E have a very high breaking strength of 3.6 to 5.09 N/mm.sup.2 and at the same time high elongation at break of 425 to 856%. This performance is a confirmation of the good filler compatibility of the polyurethane dispersion according to the present invention compared to the prior art (Comparative Example 1).

[0140] All roof membrane formulations comprising the filler compatible polyurethane dispersions show a very high extensibility of more than 500% and breaking strengths of about 2 N/mm.sup.2.