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

摘要

The invention relates to pourable, fine-particle dry powders based on a water-soluble and/or water-distendable combination of non-ionogenic cellulose ethers and dried redispersion polymers mixed, if desired, with other additives with and/or without adhesive force. The new dry powders are characterized by a particle structure with the closed nuclei of the non-ionogenic cellulose ethers surrounded by a sheath for the redispersion polymers to which they firmly adhere. In another embodiment, the invention relates to a method for producing these new pourable dry powders, characterized in that the non-ionogenic cellulose ethers in powder form are mixed with the aqueous polymer dispersion and the temperature of the aqueous phase is maintained at least at the cloudiness or flocculation point of the non-ionogenic cellulose ether or above. Under these conditions, the aqueous mixture of substances is spray-dried. The new composite materials are suitable for a wide range of applications as adhesives and/or binders with improved properties.