Powder redispersible in water, process for production thereof and use thereof

Abstract

The present invention relates to a process for the production of powders redispersible in water comprising an organic component and a water-soluble organic polymeric protective colloid. The organic component is dispersed and stabilized with the protective colloid in water to form a stable dispersion which is dried to form the powder redispersible in water. The organic component comprises abietic acid, sylvic acid, neoabietic acid, levopinaric acid, pimaric acid, isopimaric acid and/or palustric acid and/or their derivatives. The water-soluble organic polymeric protective colloid comprises synthetic protective colloids and naturally and/or synthetically produced biopolymer which can be synthetically modified. The obtained powder reduces efflorescence in hydraulically set systems.

1 . Powder redispersible in water comprising:
 an organic component having at least one compound with a cyclic group, the compound being completely or partially saturated and having a melting point approximately −20 to 250° C. and a molecular weight of about 100 to 10,000, the organic component further having a terpeneoid, a resin acid, colophony, terpene resin, terpene-phenol resin and/or their derivatives, and   a water soluble organic polymeric protective colloid, wherein the organic component and the protective colloid form a stable dispersion in water, the water-soluble organic polymeric protective colloid having a content of monocarboxylic acid and dicarboxylic acid as well as their anhydrides of less than 50 mole %, and not consisting of aromatic sulfonic acid, condensates, and   wherein the weight ratio of the organic component to the water-soluble organic polymeric protective colloid is 95:5 to 5:95, and   wherein the powder reduces efflorescence in hydraulically set systems.   
     
     
         2 . Powder according to  claim 1  wherein the cyclic group of the organic component is a monocyclic, dicyclic, tricyclic, tetracyclic and/or pentacyclic group. 
     
     
         3 . Powder according to  claim 1  wherein the organic component is a natural product. 
     
     
         4 . Powder according to  claim 1  wherein the organic component further comprises at least one compound with at least one carboxyl group, carbonyl group, aldehyde group and/or alcohol group. 
     
     
         5 . Powder according to  claim 1  wherein the organic component further comprises abietic acid, sylvic acid, neoabietic acid, levopinaric acid, pimaric acid, isopimaric acid and/or palustric acid and/or their derivatives. 
     
     
         6 . Powder according to  claim 1  wherein the organic component is not or only slightly soluble in acidic to neutral water. 
     
     
         7 . Powder according to  claim 1  wherein the organic component is partially or completely soluble in dilute caustic soda solution. 
     
     
         8 . Powder according to  claim 1  wherein the water-soluble organic polymeric protective colloid is a synthetic protective colloid in the form of a modified and/or unmodified polyvinyl alcohol with a degree of hydrolysis of 70 to 100 mole % and a Höppler viscosity, as 4% aqueous solution, of 1 to 50 mPas, measured at 20° C. according to DIN 53015, and/or polyvinyl pyrrolidone. 
     
     
         9 . Powder according to  claim 1  wherein the water-soluble organic polymeric protective colloid is a natural and/or synthetically produced biopolymer that can be synthetically modified. 
     
     
         10 . Process for the production of powders redispersible in water according to  claim 1  comprising:
 dispersing the organic component in water, 
 stabilizing the dispersion with the water-soluble organic polymeric protective colloid, and 
 drying the aqueous dispersion thereby forming the redispersible powders. 
 
     
     
         11 . Process according to  claim 10  wherein the solids content of the stabilized dispersion is approximately 10 to 75% by weight and the average particle size of the dispersed particles to approximately 0.05 to 50 μm. 
     
     
         12 . Process according to  claim 10  wherein further liquid and/or water-soluble additives are added before, during or after formation of the dispersion, and further additives in powder form are added during or after drying. 
     
     
         13 . Process according to  claim 10  further comprising mixing the redispersible powder with film-forming dispersion powders redispersible in water, redispersible hydrophobing agents in powder form based on silanes, siloxanes, silicones, fatty acids and/or fatty acid esters and/or polysaccharide ethers. 
     
     
         14 . Process according to  claim 10  wherein the aqueous dispersion is dried jointly with at least one other dispersion based on film-forming polymers and/or silanes, silane esters, siloxanes, silicones, fatty acids and/or fatty acid esters, wherein the dispersions are mixed with each other before drying or sprayed separately and subsequently dried jointly. 
     
     
         15 . Process according to  claim 14  wherein the aqueous dispersion is stabilised by emulsifiers and the at least one other dispersion comprises an excess of water-soluble organic polymeric protective colloid in water, the water-soluble organic polymeric protective colloid having a content of monocarboxylic and dicarboxylic acids and their anhydrides of less than 50 mole % and not consisting of aromatic sulfonic acid condensates. 
     
     
         16 . Powder redispersible in water obtained according to the process according to  claim 15 .