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US 5,703,156 AGranted
Dispersible powder binders
AssigneePolymer Latex GmbH & Co. KG
InventorThomas Sauer
Life of this patent
Estimating the term…
Abstract
Dispersible powdered binders prepared from aqueous acrylate dispersions stabilized by protective colloids and water soluble or water dispersible resins. The binders are suitable for the production of powdered dry paint and coating composition mixtures which can be converted into useful form simply by stirring into water.
Claims13
A redispersible powdered binder, comprising:
- (I) an aqueous acrylate dispersion stabilized with a protective colloid having a solids content of 10 to 65 wt. %;
- and
- (II) 0.01 to 30 wt. %, based on 100 wt. % of component (I) of a water-soluble or water-dispersible resin having a mean molecular weight ranging from 2000 to 100,000 g/mol, consisting of
- (a) 50 to 70 wt. % of at least one hydrophobic monomer, essentially insoluble in water by having a solubility in water of less than 3 wt. % at 25.degree. C., and
- (b) 50 to 30 wt. % of at least one hydrophilic monomer, which is soluble in water and which forms salts, where the solubility of these monomers in metal or ammonium salt form in water is at least 10 wt. % at 25.degree. C.;
- prepared by spray-drying the combination of components (I) and (II) in a hot air stream to form the powdered binder with the formation of little dust.
3 more elements
A method for the preparation of a redispersible powdered binder, comprising:
- spray-drying a mixture of an aqueous acrylate dispersion and from 0.01 to 30 wt. %, based on 100 wt. % of said aqueous acrylate dispersion, of a water-soluble or water-dispersible resin in a spray-dryer having an entry temperature of 80.degree. to 150.degree. C. and an exit temperature of 40.degree. to 100.degree. C., thereby forming said powdered, free-flowing binder having little dust, said aqueous acrylate dispersion (I) being stabilized with a protective colloid having a solids content of 10 to 65 wt. %;
- and said water-soluble or water-dispersible resin (II) having a mean molecular weight ranging from 2000 to 100,000 g/mol, consisting of
- (a) 50 to 70 wt. % of at least one hydrophobic monomer essentially insoluble in water having a solubility in water of less than 3 wt. % at 25.degree. C., and
- (b) 50 to 30 wt. % of at least one hydrophilic monomer, which is soluble in water and which forms salts, the metal or ammonium salt form of the monomer having a solubility of at least 10 wt. % at 25.degree. C. in water.
1 more element
Dependencies are inferred from the claim text.