Agglomerated particles of finely divided polymers which are,water-soluble or capable of swelling in water and contain ammonium carboxylate groups

Abstract

Agglomerated polymer particles of finely divided, water-soluble or water-swellable polymers containing ammonium carboxylate groups are prepared by azeotropic removal of water from water-in-oil emulsions of the water-soluble or water-swellable polymers which contain ammonium carboxylate groups in the presence of from 0:1 to 40% by weight, based on the polymers, of polyalkylene glycols which have an agglomerating effect and which are obtainable by an addition reaction of C 2 -C 4 -alkylene-oxides with alcohols, phenols, amines or carboxylic acids and contain at least two polymerized alkylene oxide units and additionally of from 0.1 to 20% by weight, based on the polymers, of protective colloids which are obtainable by free radical copolymerization of C 8 -C 40 -monoolefins with monoethylenically unsaturated C 4 -C 6 -dicarboxylic anhydrides by a mass polymerization method at from 80 to 300° C. to give copolymers having molecular weights of from 500 to 20,000 g/mol, and said agglomerated polymer particles are used as thickeners for textile pigment print pastes.

We claim:  
     
         1 . Agglomerated particles of finely divided, water-soluble or water-swellable polymers which contain ammonium carboxylategroups and at least 50% by weight of a monoethylenically unsaturated carobxylic acid as polymerized units, the agglomerated particles having a mean particle diameter of from 20 to 2500 μm and consisting of primary particles having a mean particle diameter of from 0.1 to 15 μm, which are obtainable by polymerization of monomer mixtures of at least 50% by weight of monoethylenically unsaturated carobyxlic acids and, if required, other monoethylenically unsaturated monomers and, if required, crosslinking agents by a water-in-pok polymerization method and can be prepared by azeotropic removal of water from the water-in-oil polymer emulsion containing the primary particles, in the presence of polyalkylene glycols which have an agglomerating effect and which 
 b) are obtainable by an addition reaction of C 2 -C 4 -alkylene oxides with alcohols phenols, amines or carboxylic acids and  
 c) contain at least two polymerized aklylene oxide units  
 and the agglomerated polymer articles disintegrating into the primary particles on introduction into an aqueous system, wherein the azeotropic removal of water i additionally carried out in the presence of from 0.1 to 20% by weight, based on the polymers, of protective colloids which are obtainable by free radical copolymerization of  
 a) C 8 -C 40 -monoolefins with  
 b) monoethylenically unsaturated C4-C6-dicarboxylic anhydrides  
 by a mass polymerization method at from 80 to 300° C. to give copolymers having molecular weights of from 500 to 20,000 g/mol.  
 
     
     
         2 . A process for the preparation of agglomerated polymer particles as claimed in  claim 1  by azeotropic removal of water from water-in-oil emulsions of water-soluble or water-swellable polymers which contain ammonium carboxylate groups and have a mean particle diameter of from 0.1 to 15 μm, in the presence of from 0.11 to 40% by weight, based on the polymers, of polyalkylene glycols which have an agglomerating effect and which 
 a) are obtainable by an addition reaction of C 2 -C 4 -alkylene oxides with alcohols, phenols, amines or carboxylic acids and  
 b) contain at least two polymerized alkylene oxide units,  
 and isolation of the agglomerated polymer particles, wherein the azeotropic removal of water is additionally carried out in the presence of from 0.1 to 20% by weight, based on the polymers, of protective colloids which are obtainable by free radical copolymerization of  
 a) C 8 -C 40 -monoolefins with  
 b) monoethylenically unsaturated C 4 -C 6 -dicarboxylic anhydrides  
 by a mass polymerization method at from 80 to 300° C. to give copolymers having molecular weights of from 500 to 20,000 g/mol.  
 
     
     
         3 . A process for the preparation of agglomerated polymer particles as claimed in  claim 2 , wherein, in the polymerization, acrylic acid, methacrylic acid or a mixture of acrylic acid and methacrylic acid is used as the water-soluble monomers and methylenebisacrylamide is used as the crosslinking agent, and the carboxylic acids may be present in a form partially or completely neutralized with ammonia.  
     
     
         4 . A process as claimed in  claim 2 , wherein, in the copolymerization, a mixture of acrylic acid and acrylamide and/or methacrylamide or a mixture of methacrylic acid and/or acrylamide and methacrylamide is used as the water-soluble monomers and methylenebisacrylamide is used as the crosslinking agent.  
     
     
         5 . A method of using agglomerated polymer particles as claimed in  claim 1  as thickeners for textile pigment print pastes.