Formulations based on anionically stabilised, aqueous polymer dispersions
Formulations based on anionically stabilized aqueous polymer dispersions, containing polychloroprene, to which carbon dioxide (CO 2 ) has been added, to a process for their preparation, to a device for increasing the carbon dioxide content of formulations based on anionically stabilized aqueous polymer dispersions, and to the use thereof in the production of adhesives, sealants, large-volume parts or coatings.
1. A process for the preparation of a formulation based on an aqueous polymer dispersion containing >20 wt. % of an anionically stabilised polychloroprene dispersion, wherein the total solids concentration=100 wt. %, characterised in that, at a pH value of from 6 to 10, the amount of dissolved carbonic acid in the dissociation equilibrium is from 0.0001 to 2 wt. %, based on the dispersion, the process comprising feeding carbon dioxide in an amount, per liter of formulation, of from 0.1 to 20 liters at from 1 to 100° C. and from 0.8 to 10 bar to an aqueous polymer dispersion containing an anionically stabilised polychloroprene dispersion.
2. The process according to claim 1 , characterised in that the carbon dioxide volumes are supplied by overlayering of the dispersion inside a resilient vessel, and the vessel is then shaken or stirred or stored until the desired reduction in volume of the gas phase has been achieved, and any excess carbon dioxide is let off.
3. The process according to claim 1 , wherein at a pH value of from 6.5 to 9.5, the amount of dissolved carbonic acid in the formulation is from 0.001 to 1 wt. %.
4. The process according to claim 1 , wherein the formulation has an alkali ion concentration (Na + +K + ) from 500 to 10,000 ppm.
5. The process according to claim 1 , wherein the formulation comprises hydrophilised polyisocyanates.
6. The process according to claim 5 , wherein the hydrophilised polyisocyanates are based on aliphatic isocyanates.
7. The process according to claim 1 , wherein the formulation comprises contains nanodisperse silicic acid suspensions in water.
8. The process according to claim 1 , wherein the formulation has a pH value stability according to DIN 53381, Method B, of >1 hour.
9. A process for preparing adhesive formulations, comprising applying a formulation produced by the process according to claim 1 to a substrate.
10. A process for producing foamed, optionally tacky sealants and insulating materials, large-volume parts, coatings, adhesive foams or dipped goods, comprising foaming a formulation produced by the process according to claim 1 .
11. A process for producing a hydrogel, comprising controlled gelling of a formulation produced by the process according to claim 1 to form a hydrogel.