Coatings, solvent thickeners

This type of thickener is based on modified ureas dissolved in N-methylpyrrolidone, which are insoluble in common coating solvents. Upon careful incorporation into coating systems, the controlled precipitation of additive forms very fine, needle-like microcrystals. The crystals form a three-dimensional lattice structure via hydrogen bonding, which results in thixotropic behavior of the system. 

Uses Solvent, thickener for cosmetics, topical pharmaceuticals, sparkling clear water or hydroalcoholic topical gels, aq. or solv. systems food-pkg. adhesives, coatings, paper/paperboard, polymers defoamer in food-contact coatings Features For use with or without neutralizing... 

In fluorescent lamps, phosphors are coated on the inside of the lamp tube using a slurry containing the powder and a Hquid which is either poured down through the tube, up-flushed, or in some cases the tubes are filled and then drained. Because of concerns over having volatile organic solvents in the air, the hquid medium containing the powder is usually water with an added agent, a thickener, to increase the viscosity of the suspension, such as poly(methacryhc... 

Suspension polymerization also is used When acrylic monomers or their mixtures with other monomers are polymerized while suspended (usually in aqueous system), the polymeric product is obtained m the form of small beads, sometimes called pearls or granules. Bead polymers are the basis of the production of molding powders and denture materials. Polymers derived from acrylic or methacrylic acid furnish exchange resins of the carboxylic acid type. Solutions in organic solvents furnish lacquers, coatings and cements, while water-soluble hydrolysates are used as thickeners, adhesives, and sizes. 

Protein produced from solvent-extracted meal has been used as a thickening agent in soups, baby foods, high-protein foods, instimtional meals, and meat products. Groundnut proteins have also been used to manufacture a soft, wool-like, cream-colored fiber, adhesive products such as plywood glue and wettable glue, and for paper coating. 

Use Stabihzer, thickener, binder, formation of film in silk-screen and gravure printing inks protective coatings aqueous, aqueous-organic, and organic solvent systems. 

Magnetic tapes are usually coated with coatings from solvents, such as methyl ethyl ketone, methyl isobutyl ketone, and toluene. Aqueous replacements can eliminate all or nearly all of the solvents.352 One system used iron oxide in a blend of a polyurethane and ethylene-vinyl chloride copolymer emulsions thickened with hydroxyethyl cellulose, which was cross-linked with a melamine-formaldehyde resin. Coating was done at line speeds of 100 m/min. The whole system proved to be 15% cheaper than coating from solvent. In another system, traces of methanol are evolved on drying and would have to be captured. This replaces a line where 600 kg/h of solvent would have to be recovered and recycled. 

---