Aqueous binder compositions for mineral wool products

A method of manufacturing an insulation product comprising;

• collecting a plurality of inorganic fibers on a substrate, said inorganic fibers being formed of a composition comprising at least 25 wt. % of bi- and tri-valent metal oxides;
• applying an aqueous binder composition to the collection of inorganic fibers, forming binder-coated inorganic fibers, the aqueous binder composition comprising:
• from more than 50 wt. % to less or equal to 88.75 wt. % solids of a crosslinking agent comprising at least two carboxylic acid groups, wherein the crosslinking agent comprises polyacrylic acid;
• from 10.0 to 40.0 wt. % solids of a polyol component having at least two hydroxyl groups;
• from 1.25 to 40.0 wt. % solids of a nitrogen-based protective agent, wherein said nitrogen-based protective agent comprises at least one of an amine-based protective agent or an ammonium based protective agent and temporarily blocks at least 40% the carboxylic acid groups of the crosslinking agent;
• removing the nitrogen-based protective agent by heating the binder-coated inorganic fibers to a temperature of at least 150° C.;
• and
• curing the aqueous binder composition via an esterification reaction between the crosslinking agent and the polyhydroxy component, forming an inorganic fibrous insulation product, wherein said aqueous binder composition is free of added formaldehyde.