POLYURETHANE DISPERSIONS FOR SEALING THE TEATS OF THE MAMMARY GLANDS IN MILKING ANIMALS

1 - 15 . (canceled)

16 . An aqueous polyurethane dispersion for sealing teats of animal mammary glands.

17 . The aqueous polyurethane dispersion of claim 16 , wherein the polyurethane dispersion is anionically and/or nonionically hydrophilized.

18 . The aqueous polyurethane dispersion of claim 16 , wherein the polyurethane dispersion is obtained by preparing

A) isocyanate-functional prepolymers from

A1) organic polyisocyanates,

A2) polymeric polyols having number-average molecular weights of 400 to 8000 g/mol, and OH functionalities of 1.5 to 6, and

A3) optionally hydroxy-functional compounds having molecular weights of 62 to 399 g/mol, and also

A4) optionally isocyanate-reactive, anionic or potentially anionic and/or optionally nonionic hydrophilizing agents, and

B) then reacting some or all of the free NCO groups of said prepolymers

B1) optionally with amino-functional compounds having molecular weights of 32 to 400 g/mol and

B2) with amino-functional, anionic or potentially anionic hydrophilizing agents with chain extension, and dispersing the prepolymers in water before, during or after step B).

19 . The aqueous polyurethane dispersion of claim 18 , wherein components A1) to A4) and B1) to B2) are used in the following amounts, wherein the sum of the individual amounts total 100% by weight:

from 5% to 40% by weight of component A1),

from 55% to 90% by weight of A2),

from 0.5% to 20% by weight of the sum of components A3) and B1), and

from 0.1% to 25% by weight of the sum of components A4) and B2),

and using, based on the total amounts of components A1) to A4) and B1) to B2), 0.1% to 5% by weight of anionic and/or potentionally anionic hydrophilizing agents from A4) and/or B2).

20 . The aqueous polyurethane dispersion of claim 16 , wherein the number-average particle size of the particles in the polyurethane dispersions, as determined by means of laser correlation spectroscopy, is less than 750 nm.

21 . The aqueous polyurethane dispersion of claim 16 , wherein the polyurethane dispersion has solids contents of 10% to 70% by weight, based on the polyurethane contained therein.

22 . The aqueous polyurethane dispersion of claim 16 , wherein the polyurethane dispersion contains less than 5% by weight, based on the total dispersion, of unbound organic amines.

23 . The aqueous polyurethane dispersion of claim 16 , wherein there are no volatile amines and no ammonia in the polyurethane dispersion.

24 . The aqueous polyurethane dispersion of claim 16 , wherein in the polyurethane dispersion there is less than 2% by weight of organic solvents.

25 . The aqueous polyurethane dispersion of claim 16 , wherein there is at least one active biocidal ingredient in the polyurethane dispersion.

26 . The aqueous polyurethane dispersion of claim 16 , wherein the active biocidal ingredient is pesticidal, fungicidal, algicidal, insecticidal, herbicidal, spermicidal, parasiticidal, antibacterial, bacteriostatic, antibiotic, antimycotic, antiviral, virostatic and/or antimicrobial.

27 . The aqueous polyurethane dispersion of claim 16 , wherein the coating is applied to teats of the udder of dairy cows.

28 . The aqueous polyurethane dispersion of claim 27 , wherein the polyurethane dispersion is applied to the teats during the dry phase of the dairy cows.

29 . The aqueous polyurethane dispersion of claim 18 , wherein A2) are polymeric polyols having number-average molecular weights of 400 to 6000 g/mol, and OH functionalities of 1.8 to 3.

30 . The aqueous polyurethane dispersion of claim 18 , wherein A2) are polymeric polyols having number-average molecular weights of 600 to 3000 g/mol, and OH functionalities of 1.9 to 2.1.

31 . The aqueous polyurethane dispersion of claim 20 , wherein the number-average particle size of the particles in the polyurethane dispersions, as determined by means of laser correlation spectroscopy, is less than 500 nm.

32 . The aqueous polyurethane dispersion of claim 21 , wherein the polyurethane dispersion has solids contents of 30% to 70% by weight, based on the polyurethane contained therein.

33 . The aqueous polyurethane dispersion of claim 21 , wherein the polyurethane dispersion has solids contents of 30% to 65% by weight, based on the polyurethane contained therein.

34 . The aqueous polyurethane dispersion of claim 22 , wherein the polyurethane dispersion contains less than 0.2% by weight, based on the total dispersion, of unbound organic amines.

35 . The aqueous polyurethane dispersion of claim 24 , wherein in the polyurethane dispersion there is less than 1.5% by weight of organic solvents.

36 . The aqueous polyurethane dispersion of claim 24 , wherein in the polyurethane dispersion there is less than 1% by weight of organic solvents.

37 . The aqueous polyurethane dispersion of claim 24 , wherein in the polyurethane dispersion there is less than 0.5% by weight of organic solvents.