FREE-FLOWING, QUICK-DISSOLVING DRY ADHESIVE POWDERS, A PROCESS FOR THEIR PRODUCTION AND USE

摘要

D 8518 A b s t r a c t Free-flowing. quick-dissolving dry adhesive powders. a process for their production and their use The invention relates to free-flowing, fine-grained dry powders based on a water-soluble and/or water-swellable combination of nonionic cellulose ethers and dried redispersion polymers, if desired in admixture with other adhesive and/or non-adhesive auxiliaries. The new dry powders are characterized by a grain structure which comprises closed cores of the nonionic cellulose ethers surrounded by and joined firmly to a shell of the redispersion polymer. In another embodiment, the invention relates to the process for the production of these new free-flowing dry powders which is characterized in that the nonionic cellulose ethers are thoroughly mixed in the form of a powder with the aqueous polymer dispersion, the temperature of the aqueous phase is kept at least at or above the cloud or flocculation point of the nonionic cellulose ethers used and the aqueous mixture is subjected to spray drying under these conditions. The new combination materials may be widely used as adhesives and/or binders having improved properties.