Aqueous binders for granular and/or fibrous substrates

1. An aqueous binder, consisting essentially of, as active constituents:

a) polymer A, comprising a polymer obtained by free-radical polymerization,

wherein the polymer comprises, in polymerized form:

≧5 and ≦100 wt %

of monomer A1, α,β-monoethylenically

unsaturated mono- or dicarboxylic acid and/or

anhydride, and

≧0 and ≦95 wt %

of of monomer A2, comprising ethylenically

unsaturated compound which is copolymerizable

with the monomers A1,

wherein a total amount of the monomers A1 and A2 is 100 wt %,

b) polyol B, comprising a nitrogen-free polyol compound having at least two hydroxyl groups, and

c) nitrogen base C, comprising a hydroxyl-free organic nitrogen compound having at least one pK B value ≦7, which is measured at 25° C. in deionized water and/or a hydroxyl-free imidazole compound;

wherein the amount of nitrogen base C in the aqueous binder is ≧5 and ≦20 parts by

weight, based on 100 parts by weight of polymer A and an equivalent ratio of carboxyl groups on the polymer A to hydroxyl groups on the polyol B is from 20:1 to 1:1.

2. The aqueous binder according to claim 1 ,

wherein the polymer A is dissolved or dispersed in an aqueous medium.

3. The aqueous binder according to claim 1 ,

wherein the polymer A comprises, in polymerized form:

≧70 and ≦100 wt %

of the monomer A1, and

≧0 and ≦30 wt %

of the monomer A2.

4. The aqueous binder according to claim 1 ,

wherein the polymer A comprises, in polymerized form:

≧85 and ≦100 wt %

of acrylic acid, methacrylic acid, maleic acid,

maleic anhydride and/or itaconic acid, and

≧0 and ≦15 wt %

of methyl acrylate, ethyl acrylate, n-butyl

acrylate, 2 ethylhexyl acrylate, methyl

methacrylate and/or styrene.

5. The aqueous binder according to claim 1 ,

wherein the polyol B is at least one selected from the group consisting of glycerol, trimethylolpropane, and polyvinyl alcohol.

6. The aqueous binder according to claim 1 ,

wherein the nitrogen base C at 20° C. has a solubility ≧0.5 g in 100 g of deionized water.

7. The aqueous binder according to claim 1 ,

wherein the nitrogen base C has a boiling point ≧40° C. at 1 atm (absolute).

8. The aqueous binder according to claim 1 ,

wherein the nitrogen base C is at least one selected from the group consisting of n-propylamine, n-butylamine, n-hexylamine, diethylamine, di-n-propylamine, di-n-butylamine, triethylamine, tri-n-propylamine, imidazole, and 1- methylimidazole.

9. The aqueous binder according to claim 1 ,

wherein the weight ratio of polymer A to polyol B (based on solids) is 50:1 to 1.5:1.

10. The aqueous binder according to claim 1 ,

wherein an amount of a phosphorus component is <1 wt %, based on summed amounts of the polymer A and the polyol B.

11. An aqueous binder, consisting of, as active constituents:

a) polymer A, comprising a polymer obtained by free-radical polymerization,

wherein the polymer comprises, in polymerized form:

≧5 and ≦100 wt %

of monomer A1, comprising an α,β-

monoethylenically unsaturated mono-

or dicarboxylic acid, and

≦0 and ≦95 wt %

of monomer A2, comprising an ethylenically

unsaturated compound which is

copolymerizable with the monomer A1,

wherein a total amount of the monomers A1 and A2 is 100 wt % and neither monomer A1 nor monomer A2 is an ethylenically unsaturated anhydride,

b) polyol B, comprising a nitrogen-free polyol compound having at least two hydroxyl groups, and

c) nitrogen base C, comprising a hydroxyl-free organic nitrogen compound having at least one pK B value ≦7, which is measured at 25° C. in deionized water and/or a hydroxyl-free imidazole compound, and

d) <1 wt % of a phosphorus component, based on summed amounts of the polymer A and the polyol B;

wherein the amount of nitrogen base C in the aqueous binder is ≧5 and ≦20 parts by weight, based on 100 parts by weight of polymer A, and an equivalent ratio of carboxyl groups on the polymer A to hydroxyl groups on the polyol B is from 20:1 to 1:1.

12. The aqueous binder according to claim 11 ,

wherein the polymer A is dissolved or dispersed in an aqueous medium.

13. The aqueous binder according to claim 11 ,

wherein the polymer A comprises, in polymerized form:

≧70 and ≦100 wt %

of the monomer A1, and

≧0 and ≦30 wt %

of the monomer A2.

14. The aqueous binder according to claim 11 ,

wherein the polymer A comprises, in polymerized form:

≧85 and ≦100 wt %

of acrylic acid, methacrylic acid, maleic acid,

and/or itaconic acid, and

≧0 and ≦15 wt %

of methyl acrylate, ethyl acrylate, n-butyl

acrylate, 2 ethylhexyl acrylate, methyl

methacrylate and/or styrene.

15. The aqueous binder according to claim 11 ,

wherein the polyol B is at least one selected from the group consisting of glycerol, trimethylolpropane, and polyvinyl alcohol.

16. The aqueous binder according to claim 11 ,

wherein the nitrogen base C has a boiling point ≧40° C. at 1 atm (absolute).

17. The aqueous binder according to claim 11 ,

wherein the nitrogen base C is at least one selected from the group consisting of n-propylamine, n-butylamine, n-hexylamine, diethylamine, di-n-propylamine, di-n-butylamine, triethylamine, tri-n-propylamine, imidazole, and 1- methylimidazole.

18. The aqueous binder according to claim 11 ,

wherein the weight ratio of polymer A to polyol B (based on solids) is 50:1 to 1.5:1.

19. The aqueous binder according to claim 10 ,

wherein the binder contains no phosphorous component.

20. The aqueous binder according to claim 11 ,

wherein the binder contains no phosphorous component.