Agents wetting

It may be necessary to add wetting and dispersing agents and a defoamer to the millbase. If formulated correctly, pigments and extenders can be dispersed easily. 

Care has to be taken to ensure that the equipment is suitable for use with water, as rusting will occur very rapidly in mild steel equipment, particularly with the heat generated in the milling process. Stainless steel is reconunended for use throughout. 

Dispersants prevent re-agglomeration and maintain stability by one of three general mechanisms 

The first two utilise a principle of charge repulsion whilst the third works through steiic hindrance. In most waterborne systems, anionic dispersants are preferred due to their greater efficiency. Cationic dispersants are only used in specialised instances. Of the many types that are available, the following are most commonly used  

Some common dispersants and surfactants aie given in Table 7-9. 

That is, a wetting agent acts to reduce the surface tension of the ink so that a more uniform surface energy on the surface of the nozzle plate is achieved. This action has been observed to minimize puddling of the ink on the surface of the nozzle plate. Wetting agents are summarized in Table 3.3. 

It has been foimd that the use of a wetting agent in an ink composition may permit a reduced amoimt of penetrant used in the composition. Thus, less penetrant may be used and yet still achieve desirable prevention of intercolor bleed on the printed substrate, while providing for a rapid ink drying (5). 

---

Aerosol is also a trade name for certain wetting agents, most of which are esters of sodium sulphosuccinic acid. 

I wetting agent for textiles, surface-active agent, [ food additive... 

Antlblaze 19. Antiblaze 19 (Mobil), a flame retardant for polyester fibers (134), is a nontoxic mixture of cycHc phosphonate esters. Antiblaze 19 is 100% active, whereas Antiblaze 19T is a 93% active, low viscosity formulation for textile use. Both are miscible with water and are compatible with wetting agents, thickeners, buffers, and most disperse dye formulations. Antiblaze 19 or 19T can be diffused into 100% polyester fabrics by the Thermosol process for disperse dyeing and printing. This requires heating at 170—220°C for 30—60 s. 

The anhydrous salt is prepared by several methods, eg, by reacting ZrCl with liquid anhydrous HP. It is necessary to use an excess of HP which also acts as a wetting agent. The reaction is instantaneous and is carried out in a polyethylene jar or carboy. When the evolution of HCl ceases, the material is transferred to a tray and dried under an atmosphere of nitrogen. By proper selection of equipment, purification of raw material, and drying conditions, materials of spectrographic purity can be produced (4). 

The low surface tension of highly fluorinated organic compounds is commercially important for their appHcation in surfactants, antisoiling textile treatments, lubricants, and specialty wetting agents. 

Docusate sodium is both a surface-active agent for use as a fecal softener, and a wetting agent in industrial, pharmaceutical, cosmetic, and food apphcations. 

Chocolate (0.3—0.5% lecithin) lecithin is a wetting agent and emulsifier. It facihtates mixing, saves processiag time and power, saves cocoa butter, stabilizes viscosity, iacreases shelf life, counteracts moisture thickening, and aids release of molded goods (see Chocolate and cocoa). 

Edible Oils and Fats. lecithin (0.01—2%) is used as an emulsifier, wetting agent, and antioxidant it extends shelf hfe, especially of animal fats iacreases lubricity (shortening value) improves stabiUty of compouad shortenings and lowers cloud poiat of vegetable oils. 

Naphthalenesulfonic acids are important chemical precursors for dye intermediates, wetting agents and dispersants, naphthols, and air-entrainment agents for concrete. The production of many intermediates used for making a2o, a2oic, and triphenylmethane dyes (qv) involves naphthalene sulfonation and one or more unit operations, eg, caustic fusion, nitration, reduction, or amination. 

All lnaphthalenesulfonic Acids. The aLkyLnaphthalenesulfonic acids can be made by sulfonation of aLkyLnaphthalenes, eg, with sulfuric acid at 160°C, or by alkylation of naphthalenesulfonic acids with alcohols or olefins. These products, as the acids or their sodium salts, are commercially important as textile auxiUaries, surfactants (qv), wetting agents, dispersants (qv), and emulsifying aids, eg, for dyes (qv), wettable powder pesticides, tars, clays (qv), and hydrotropes. 

Wetting agents are used to make a water rinse remover. Water rinse removers are normaUy used for removing paint, where the surfactants help remove paint and remover from the substrate. Solvent rinse removers or wipe and dry formulas may be used for stripping clear finishes. A typical petroleum and oxygenate formula is as foUows (10). 

Solids present in oil and synthetic muds must be kept wet with the nonaqueous phase to prevent coagulation and settling and mud instabiUty. Oil-wetting agents are normally incorporated in the basic mud package. These materials are typically amines or quaternary ammonium salts having hydrocarbon chains of 10 or more carbon atoms. They also render clays or lignites oil-wet for use in viscosity and filtration control (128). 

---