Aqueous Liquor

Since PES fibers are hydrophobic, water-soluble dyes do not attach. In contrast, PES fibers can be dyed easily with water-insoluble, small molecular dyes originally developed for dyeing cellulose acetate. Since the preferred dyeing medium is an aqueous liquor, the poorly water-soluble dyes must be dispersed before application (Section 3.2). 

More than 50% of disperse dyes are simple azo compounds, about 25% are anthraquinones, and the rest are methine, nitro, and naphthoquinone dyes (see Sections 2.2, 2.3, 2.6, 3.12). 

Since the fundamental work of Meyer and Kartaschoff in 1925 [112] and the studies of Vickerstaff [54] in the early 1950s, a large number of studies have been published on the kinetics and thermodynamics of dyeing cellulose acetate and syn- 

The water solubility of pure disperse dyes is a few milligrams per liter and increases strongly with temperature. It is also increased manyfold by dispersing agents [116], 

The diffusion coefficient D is 10 10 to 10 12 cm2/s and can be increased only by an increase in temperature. The diffusion path h is predetermined by fiber geometry the concentration gradient CL-CF, by CL. 

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Sometimes an air bubble enters the tube E and prevents the regular flow of liquid from B the air bubble is easily removed by shaking the rubber tube. The flask A is heated (e.g., by a ring burner) so that distillation proceeds at a rapid rate the process is a continuous one. If the liquid to be steam distilled is lighter than water, the receiver must be modified so that the aqueous liquors are drawn off from the bottom (see Continvmia Extraction of Liquids, Section H, 44). 

Sodium (9.6 parts) was dissolved in butanol (192 parts) and di-n-butyl ethyl 1 -methyl-n-butylmalonate (62,B parts) and urea (14.4 parts) were added to the warm solution with agitation. The mixture was then heated to reflux temperature in three quarters of an hour and maintained for 2 hours. The reaction mass was kept, water (150 parts) added, the aqueous portion separated, and the butanol layer extracted with water (3 x 50 parts). The combined aqueous extracts were then given 3 small extractions with benzene, the aqueous liquors separated, charcoaled,filtered and precipitated with concentrated hydrochloric acid (acid to congo-paper). The solid was collected, washed with water, dissolved in N-sodium hydroxide and reprecipitated with carbon dioxide. On recrystallization, from aqueous alcohol, the pentobarbitone was obtained. 

Introduction of a second solvent, incompatible with the continuous phase of a normally stable dispersion, produces an unstable condition if the new solvent wets the surface of the solid better than does the original vehicle. The instability induced by the introduction of a oily vehicle to an aqueous dispersion of an organic pigment is exploited commercially in the so-called flushing of pigments from an aqueous liquor into a vehicle. 

Fig. II, 41, 4 is an apparatus for the continuous steam distillation of a liquid which is heavier than water. The aqueous mixture is placed in the flask A of relatively large capacity the receiver B consists of a distilling flask (provided with a stopcock at the lower end), the capacity of which is less than the volume of the liquid in A, and is placed several inches higher than the opening in the wide vertical tube C. The lower end of the funnel D must-be below the side arm of the receiver in order to prevent bubbles of the heavy liquid from collecting on the surface of the steam distillate and being carried back to the flask A. The rubber tube E for the returning aqueous liquor must at some point be lower than the entrance to the tube C so that a trap of liquid will be formed and prevent the vapours from A entering the side tube.

Nitrophenylpyruvic acid was reduced to oxindole using iron pin-dust-ferrous sulfate in water. The iron oxide-iron residues, after filtering and washing with chloroform, rapidly heated in contact with air and shattered the Buchner funnel [1], Previously, rapid heating effects had been observed on sucking air through the iron oxide residues from hot filtration of aqueous liquor from reduction of a nitro compound with reduced iron powder [2],... 

A laboratory test is carried out into the extraction of acetic acid from dilute aqueous solution, by means of methyl iso-butyl ketone, using a spray tower of 47 mm diameter and 1080 mm high. The aqueous liquor is run into the top of the tower and the ketone enters at the bottom. 

Dimethylolnitramine (252) is known to be present under the conditions of the Hale nitrolysis. If the Hale nitrolysis reaction is quenched, the RDX removed by filtration and the aqueous liquors neutralized to remove DPT, the remaining filtrate can be extracted into ether and that solution evaporated over water to give an aqueous solution of dimethylolnitramine (252). ... 

In a flask fitted with a take-off adapter surmounted by a reflux condenser and a thermometer reaching to the bottom of the flask a mixture of 40.2 g (0.30 mol) of propiophenone, 40g of potassium hydroxide, 300 ml of triethylene glycol and 30 ml of 85% hydrazine hydrate (0.51 mol) is refitixed for 1 hour. The aqueous liquor is removed by means of the take-off adapter until the... 

In order to prepare pure acetoxime (Note 4), the procedure is modified in the following way After neutralizing the solution of acetoxime formed after the addition of acetone, the oily layer is separated and the aqueous solution shaken with two or three 150-cc. portions of benzene. The oil and benzene solutions are mixed, the water thereby thrown out is removed, and the oil fractionally distilled with the use of a column, the portion boiling 133-136° being collected as pure acetoxime. This product, which weighs 420-480 g., solidifies in the receiver to colorless needles melting at 60-61°. The foreruns and aqueous liquors are best distilled with steam and the distillate converted into hydroxylamine hydrochloride as above, whereupon 75-90 g. of pure salt is obtained. 

In the case of low temperature tar, the aqueous liquor that accompanies the cmde tar contains between 1 and 1.5% by weight of soluble tar acids, eg, phenol, cresols, and dihydroxybenzenes. Both for the sake of economics and effluent purification, it is necessary to recover these, usually by the Lurgi Phenosolvan process based on the selective extraction of the tar acids with butyl or isobutyl acetate. The recovered phenols are separated by fractional distillation into monohydroxybenzenes, mainly phenol and cresols, and dihydroxybenzenes, mainly o-dihydroxybenzene (catechol), methyl 0-dihydroxybenzene, (methyl catechol), and tn- dihydro xyb enzene (resorcinol). The monohydric phenol fraction is added to the cmde tar acids extracted from the tar for further refining, whereas the dihydric phenol fraction is incorporated in wood-preservation creosote or sold to adhesive manufacturers. Naphthalene Oils. Naphthalene is the principal component of coke-oven tars and the only component that can be concentrated to a reasonably high content on primary distillation. Naphthalene oils from coke-oven tars distilled in a modem pipe still generally contain 60—65% of naphthalene. They are further upgraded by a number of methods. 

The acid aqueous liquors contain -aminodimethylaniline and might be utilized in the preparation of quinoneimine dyes. 

Weatherproof. Good chemical resistance to mineral acids, bases and aqueous liquors. 

Good chemical resistance to mineral acids, bases and aqueous liquors. Outstanding resistance to media with oxidizing effects such as sodium hypochlorite and chromic acid. 

If another run is to be made immediately, the reduced liquor may be removed by means of a siphon or pipette. If it is decanted, a little vaseline rubbed on the edge of the vessel will aid in pouring off the aqueous liquor from the mercury. 

Solution and Dispersion Behavior. For the dyeing process in aqueous liquor, the dye must have adequate solubility or dispersibility. In general, good solubility is necessary for good application properties. If the solubility is poor (i.e., if any of the dye is present in the dye liquor in the form of undissolved particles), local coloration (specks), spots, uneven effects, and poor fastness can be produced, leading to serious defects and costly complaints. 

Dyeing from Organic Solvents. Chlorinated hydrocarbons, in particular, have been recommended as a medium for continuous or batch dyeing of acetate and PES fibers. For continuous dyeing, dye application from either chlorinated hydrocarbons or an aqueous liquor with fixation in solvent vapor is possible. This method is disfavored for ecological and toxicological reasons [82, p. 676],... 

Continuous or semicontinuous dyeing processes are uncommon because dry heat treatment (thermosol) hardens wool. Besides, application of the wool dye requires dyeing in aqueous liquor or dye fixation by steaming. 

Methods which enploy liquid phase treating liquors (spray, transfer rolls and belts, etc.) share a cannon difficulty stemming from the lew volume of liquor in relation to the large surface area of the fibers conprising the substrate to be treated. This difficulty is acerbated when aqueous liquors are to be applied to hydrophilic fibers. Foam coating methods enploy stable foams which allow the thickness of the liquid-air mixture to be controlled by a doctor blade or roll. Conparatively low add-ons can be achieved by virtue of the low density of the foam layer, but the stable nature of such foam, and its immobile liquid phase, inhibit rapid, uniform distribution through the substrate. 

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