Liquid applied sound damping mats for flooring and compositions for making them

A trowelable aqueous composition of an aqueous polymer foam forming component and a rubbery composite component, comprising:

• as the aqueous polymer foam forming component:
• A) from 10 to 60 wt. % of one or more hard vinyl or acrylic aqueous emulsion polymers having measured glass transition temperature (measured Tgh) of from 5 to 40° C. as measured by differential scanning calorimetry (DSC) comprising heating to 160° C., rapidly cooling at 10° C./minute to −80° C., and then collecting DSC curve data while ramping the temperature at 10° C./minute up to 160° C., and recording the midpoint of the inflection of the resulting DSC curve as the Tgh,
• B) from 5 to 50 wt. % of one or more soft vinyl or acrylic aqueous emulsion polymers having a measured Tg (measured Tgs) of from 0 to −35° C. as measured by differential scanning calorimetry (DSC) comprising heating to 160° C., rapidly cooling at 10° C./minute to −80° C., and then collecting DSC curve data while ramping the temperature at 10° C./minute up to 160° C., and recording the midpoint of the inflection of the resulting DSC curve as the Tgs;
• C)(i) from 0.5 to 3 wt. % of a foam stabilizer of a 12 to 24 carbon organic acid salt, and C)(ii) from 0.05 to 0.75 wt. % of an organic foaming agent;
• and,
• as the rubbery composite component:
• D)(i) from 20 to 60 wt. % of a lightweight inorganic aggregate having a sieve particle size of from 0.3 to 4 mm and having a density of from 0.18 to 0.4 g/cm3;
• and,
• D)(ii) from 20 to 60 wt. % of crosslinked rubber (a) granules having a sieve particle size of from 0.5 to 4 mm or crosslinked rubber (b) particles having a sieve particle size of from 0.1 to less than 0.5 mm, or a mixture of the (a) granular crosslinked rubber particles and the (b) finely divided crosslinked rubber particles in a weight ratio of (a):(b) of from 99:1 to 20:80,
• wherein all wt. % s in the trowelable aqueous composition add up to 100% and are based on the total weight of all materials used to form the trowelable aqueous composition.