Method for producing an aqueous binder

Patent metadata

Field	Value
Publication number	US-10604608-B2
Application number	US-201615767211-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Nov 6, 2015
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

Process for producing an aqueous binder comprising at least one polycarboxylic acid, at least one compound having at least two hydroxyl groups, and at least one phosphorus compound.

First claim

What is claimed is:

1. A process for producing an aqueous binder that comprises at least one polycarboxylic acid A, at least one organic compound B which comprises at least two hydroxyl groups (polyol B), and at least one phosphorus compound C, the method comprising:
carrying out radical polymerization of
≥50 and ≤100 parts by weight of at least one α,β-monoethylenically unsaturated monocarboxylic or dicarboxylic acid and/or an anhydride thereof (monomer A1), and
≥0 and ≤50 parts by weight of at least one other ethylenically unsaturated compound (monomer A2), which is copolymerizable with the monomer A1,
wherein a total amount of each of the monomers A1 and A2 add up to 100 parts by weight [total monomer amount], in an aqueous medium in the presence of ≥0.5 and ≤50 wt % of at least one inorganic hydrogen sulfite salt, based on the total monomer amount, to give the polycarboxylic acid A, and thereafter

in the aqueous solution of the polycarboxylic acid A obtained (polycarboxylic acid solution), reducing an amount of free, unreacted hydrogen sulfite, calculated as sodium hydrogen sulfite (NaHSO 3 ), to an amount ≤1000 ppm, based on the polycarboxylic acid solution, and only thereafter
adding the phosphorus compound C either to the polycarboxylic acid solution, to the mixture of polycarboxylic acid solution and polyol B, and/or during the mixing of polycarboxylic acid solution and polyol B.

2. The process according to claim 1 , wherein the reducing takes place at a pH<5.

3. The process according to claim 1 , wherein an amount of the at least one phosphorus compound C is ≥0.1 and ≤40 wt %, based on an amount of the polycarboxylic acid A.

4. The process according to claim 1 , wherein an amount of the inorganic hydrogen sulfite salt is selected such that the resulting polycarboxylic acid A has a weight-average molecular weight of ≤80 000 g/mol.

5. The process according to claim 1 , wherein the monomer A1 is selected from acrylic acid, methacrylic acid, maleic acid, maleic anhydride and/or itaconic acid, and the monomer A2 is selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate and/or styrene.

6. The process according to claim 1 , wherein the inorganic hydrogen sulfite salt is sodium hydrogen sulfite.

7. The process according to claim 1 , wherein the free inorganic hydrogen sulfite is reduced by an oxidizing agent.

8. The process according to claim 7 , wherein the free inorganic hydrogen sulfite is reduced by hydrogen peroxide.

9. The process according to claim 1 , wherein the phosphorus compound C is sodium hypophosphite and/or sodium hypophosphite monohydrate.

10. The process according to claim 1 , wherein a total amount of the phosphorus compound C is added to the polycarboxylic acid solution before the mixing with the polyol B.

11. The process according to claim 1 , wherein an amount of the at least one polyol B is selected such that a molar ratio of the carboxyl groups of the at least one polycarboxylic acid A to the hydroxyl groups of the at least one polyol B is in a range of ≥0.1 and ≤10.

12. The process according to claim 1 , wherein the polyol B is an alkanolamine.

13. The process according to claim 12 , wherein an amount of the alkanolamine is ≥10 and ≤50 wt %, based on a total amount of the polycarboxylic acid A.

14. The process according to claim 12 , wherein the alkanolamine is selected from diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, methyldiethanolamine, butyldiethanolamine and/or methyldiisopropanolamine.

15. An aqueous binder obtained by the process according to claim 1 .

16. A shaped article comprising a granular and/or fibrous substrate and the binder according to claim 15 .

17. A process for producing a shaped article from a granular and/or fibrous substrate, comprising applying the aqueous binder according to claim 15 to the granular and/or fibrous substrate, and then subjecting the treated granular and/or fibrous substrate to a thermal treatment at a temperature of ≥110° C.

18. The process according to claim 17 , wherein the aqueous binder is applied in an amount of ≥0.1 g and ≤100 g (calculated as the sum total of the total amounts of polycarboxylic acid A, polyol B, and phosphorus compound C, based on solids) per 100 g of the granular and/or fibrous substrate.

19. A shaped article obtained by the process according to claim 17 .

Assignees

• Basf Se

Inventors

• Michl Kathrin
• Smit Theo
• Schilling Holger
• Faul Dieter

Classifications

• C08F220/08

  Anhydrides · CPC title

• C08K3/32

  Phosphorus-containing compounds · CPC title

• C08F4/40

  Redox systems · CPC title

• C08K2003/309

  Sulfur containing acids · CPC title

• C08K5/17

  Amines; Quaternary ammonium compounds · CPC title