A redispersible emulsion powder which is suitable for use in or as a cement admixture, powder coating material, powder adhesive, etc. The emulsion powder is excellent in miscibility with the inorganic fillers, polyvalent inorganic salts, and the like used for construction/building and in redispersibility and workability and is suitable for use as an admixture for ultrahigh-early-strength cements. The powder comprises vinyl copolymer particles having an anion-modified polyvinyl alcohol adsorbed on the surface thereof. The powder is obtained preferably by emulsion-polymerizing a vinyl monomer composition in an aqueous medium in the presence of an anion-modified polyvinyl alcohol and drying the resultant aqueous emulsion. The anion-modified polyvinyl alcohol is preferably selected among a polyvinyl alcohol modified with a sulfonic acid, a polyvinyl alcohol modified with a carboxylic acid, and a mixture of both.
This article presents classification and performance demands of self-leveling ground materials in dry mixing mortar,studys the influence of self-leveling properties for VINNAPAS RE5011L redispersible emulsion powder on self-leveling ground materials which using mineral based inorganic binder as the base material.Test results show,this redispersible emulsion powder can remarkably improve adhesion strength,tensile strength,wearability and bending strength of the self-leveling$...
The overview introduced the redispersible emulsion powder used in ceramic tile bonding, external thermal insulation composite system bonding, polymer-modlfied cement-based waterproof coating and EPS granule thermal insulation coating for the modification of the cementation material. The related formulations and using technique were recommended. The redispersible emulsion powder can improve bulding cementing materials in the flexiblity, the cracking resistance and the adhesive strength
The present invention relates to a redispersible synthetic resin powder comprising as a main component a resin made of an ethylenically unsaturated monomer and/or a diene monomer, such as acrylic resins, and the use of the powder. More particularly, the present invention relates to a redispersible synthetic resin powder having excellent properties, such as blocking resistance, dispersibility in redispersion, film forming property and water resistance of films formed from the powder, and being useful as an admixture for cement and mortar. The present invention also relates to an admixture for cement and mortar comprising the powder.
Emulsions of synthetic resins such as vinyl acetate resins and acrylic resins have been widely used in adhesives, coatings and the like. The emulsions are generally supplied in the form of liquid. The supply of liquid emulsions is disadvantageous in that the transportation is expensive, emulsions may freeze in winter or change its quality with the lapse of time and treatment of waste water may be required after the use of emulsions.
In view of these disadvantages, recently, emulsions are dried, and powders are supplied and used in various fields. Upon the use, the powders are dispersed into water again. Therefore, the powders are required to have a good redispersibility into water.
Japanese Patent Publication Kokai No. 7-157565 discloses a redispersible emulsion powder of a synthetic resin obtained by spray-drying an emulsion prepared by emulsion polymerization of ethylenically unsaturated monomer using an acetoacetylated (acetoacetyloxy group-containing) polyvinyl alcohol as a protective colloid for the purpose of improving the redispersibility and the water resistance of films formed therefrom. Japanese Patent Publications Kokai No. 9-151221 and Kokai No. 11-263848 disclose a synthetic resin powder wherein a polyvinyl alcohol polymer is chemically bonded to the surface of particles of a polymer of an ethylenically unsaturated monomer or a diene monomer through a terminal sulfide bond for the purpose of improving the redispersibility, the film forming property and the water resistance of films formed therefrom. Further, Japanese Patent Publication Kokai No. 11-279361 discloses an emulsion powder wherein a polyvinyl alcohol polymer having specific structural units such as carboxyethyl group is used for the same purpose as the above.