Coalescing solvents, latex polymers

Use Plasticizer and coalescing agent for acrylic latexes in floorpolishes, solvent for polymers, insecticides, polyhydroxylic alcohols, sugar, iodine, specialty inks, monomer for nylon-4. 

Chem. Descrip. 2-Pyrrolidone CAS 616-45-5 EINECS/ELINCS 204-648-7 Uses Monomer for polypyrrolidone solvent for polymers, insecticides, polyhydroxylic alcohols, sugars, iodine, specialty inks used in petrol, processing and acrylonitrile mfg. solvenL solubilizer, intermediate for pharmaceuticals plasticizer/coalescing agent for actylic latexes, actylic-styrene copolymers in emulsion-type floor coalings intermediate for N-methylol derivs., alkaloids related to peganine, amino-butyric acid derivs. adhesives... 

Uses Plasticizer, emulsifier, and coalescent for acrylic latexes, styrene-acrylic floor polishes solvent for polymers, insecticides, veterinary medicine selective solvent (acet ene, acrylonitrile prod.) process solvent (phamraceuticals) specialty inks monomer for nylon-4 pharmaceutical solubilizer, intermediate synthesis of piracetam treatment of cerebral distress... 

The monomer composition must be chosen carefully as it will affect the properties of the final coating and the film-forming ability of the latex. The minimum film-forming temperature (MEET) is defined as the lowest temperature at which the latex particles will coalesce to give a clear film. It is related to the glass transition temperature (Tg) of the polymer but is also influenced by the presence of other materials such as coalescing solvents, plasticizers, and surfactants. In order that the latex particles can coalesce and form a continuous film on application, the MEET must be below the temperature at which film formation will occur. For domestic paints an MEET of below 10°C is required. 

Dispersions of insoluble polymer particles form films by coalescence of the particles. The largest volume of such coatings use latexes as a binder. The lowest temperature at which coalescence occurs to form a continuous film is called its minimum film-formation temperature (MFFT). A major factor controlling MFFT is the Tg of the polymer particles. The MFFT of latex particles can be affected by water, which can act as a plasticizer (5). Most latex paints contain volatile plasticizers, coalescing solvents, to reduce MFFT. The mechanism of film formation from latexes has been extensively studied the papers in References 6-9 review various theories associated with it. Film formation occurs by three overlapping steps evaporation of water and water-soluble solvents that leads to a close packed... 

Thus, most practical latex systems require small additions of coalescing solvents to increase the drying rate. These solvents are generally not retained in the film despite having low evaporation rates. It is possible to mix the solvent so that one partitions to the hydrophilic network and the other the polymer phase. SuifKisingly, they do not interfere with the action of each other. 

Uses Wetting agent, dispersant, antistat, defoamer, gellant, solubilizer, lubricant base for cosmetic, medical, paper, pharmaceutical and textile industries coalescing solvent for plasticizing acrylic emulsion polymers, latex caulks, epoxies, alkyds, polyesters, phenolics increases flexibility and toughness, improves film formation... 

Emulsion Adhesives. The most widely used emulsion-based adhesive is that based upon poly(vinyl acetate)—poly(vinyl alcohol) copolymers formed by free-radical polymerization in an emulsion system. Poly(vinyl alcohol) is typically formed by hydrolysis of the poly(vinyl acetate). The properties of the emulsion are derived from the polymer employed in the polymerization as weU as from the system used to emulsify the polymer in water. The emulsion is stabilized by a combination of a surfactant plus a coUoid protection system. The protective coUoids are similar to those used paint (qv) to stabilize latex. For poly(vinyl acetate), the protective coUoids are isolated from natural gums and ceUulosic resins (carboxymethylceUulose or hydroxyethjdceUulose). The hydroHzed polymer may also be used. The physical properties of the poly(vinyl acetate) polymer can be modified by changing the co-monomer used in the polymerization. Any material which is free-radically active and participates in an emulsion polymerization can be employed. Plasticizers (qv), tackifiers, viscosity modifiers, solvents (added to coalesce the emulsion particles), fillers, humectants, and other materials are often added to the adhesive to meet specifications for the intended appHcation. Because the presence of foam in the bond line could decrease performance of the adhesion joint, agents that control the amount of air entrapped in an adhesive bond must be added. Biocides are also necessary many of the materials that are used to stabilize poly(vinyl acetate) emulsions are natural products. Poly(vinyl acetate) adhesives known as "white glue" or "carpenter s glue" are available under a number of different trade names. AppHcations are found mosdy in the area of adhesion to paper and wood (see Vinyl polymers). 

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