Dispersants, acidity

Dihydroxyanthraquinone. This anthraquinone, also known as quinizarin [81-64-1] (29), is of great importance in manufacturing disperse, acid, and vat dyes. It is manufactured by condensation of phthalic anhydride (27) with 4-chlorophenol [106-48-9] (28) in oleum in the presence of boric acid or boron trifluoride (40,41). Improved processes for reducing waste acid have been reported (42), and yield is around 80% on the basis of 4-chlorophenol. 

When a hydrophobic polymer with a physically dispersed acidic excipient is placed into an aqueous environment, water will diffuse into the polymer, dissolving the acidic excipient, and consequently the lowered pH will accelerate hydrolysis of the ortho ester bonds. The process is shown schematically in Fig. 6 (18). It is clear that the erosional behavior of the device will be determined by the relative movements of the hydration front Vj and that of the erosion front V2- If Vj > V2, the thickness of the reaction zone will gradually increase and at some point the matrix will be completely permeated with water, thus leading to an eventual bulk erosion process. On the other hand, if V2 = Vj, a surface erosion process wiU take place, and the rate of polymer erosion will be completely determined by the rate at which water intrudes into the matrix. 

The name of this structural class ( quinoline ) in the Colour Index is not ideal because quinoline derivatives feature in other related classes, such as the methine basic dyes with a quinolinium cationic group. The class is more precisely associated with quinophthalone (1.15), the characteristic chromogen derived by condensation of quinoline derivatives with phthalic anhydride. This small class of yellow compounds contributes to the disperse, acid, basic and solvent ranges of dyes. 

Dycs Traditionally libers are pigmented during manufacture, but some can be dyed with disperse, acid, and chelating dyes and certain vats, sulfurs. and azotes,... 

Dyes Good affinity for most classes of dyes, but disperse, acid, and premetalized dyes are generally preferred. ... 

This uronan (Stauffer, 1980 Whistler, 1993) contains a major neutral, insoluble albeit swellable component called bassorin and a minor water-dispersible, acidic component called tragacanthin. It is one of the more acid-and heat-stable, surfactant polysaccharides, and it has wide application in a miscellany of industries. The primary structures appear to be arabinogalac-tans and arabinogalacturonan methyl esters incorporating lesser quantities of xylose, rhamnose, and fucose. 

Dye Classes Pigments, Disperse Acid, Disperse, Premetallized... 

Outstanding migrating agent for disperse, acid, premetallized and cationic dyes on synthetic fibers and wool. Used as an anti-precipitant in differential dyeing with acid, disperse and cationic dyes in one bath. 

It is an effective, economical scouring and clearing agent for natural and synthetic fibers dyed or printed with disperse, acid, basic, direct, fiber reactive and other types of dyes. 

Hydrolysis of phosphatides and pigments in the crude oil miscella requires an acid pretreatment, which usually varies between 100 ppm and 500 ppm by weight of the oil, depending on the quality of the crude oil. An acid such as phosphoric or glacial acetic has been found effective in improving oil quality and reducing refining losses. Phosphoric acid is used more commonly because of its less corrosive properties and its availability. The acid is mixed with the miscella in a static mixer to provide an intimately dispersed acid phase that immediately reacts with the crude miscella. 

According to their chemical structures and the Cl system, dyes can be classified into 17 groups nitro dyes, triphenylmethane derivatives, xanthenes, acridine derivatives, quinoline derivatives, azines, ant-hraquinones, indigoid dyes, phthalocyanines dyes, oxydation bases, insoluble azo dye precursors, and azo dyes (classes XII-XVII). In practice, dyes are classified into different application classes disperse, acid, basic, direct, vat, fiber-reactive, sulfur, preme-tallic, solvent dyes, and naphthols. 

Efforts have been made to combine greater wet-fastness with the ease of application of the molecularly-dispersed acid dyes. Dyes of low molecular weight are improved by introducing an co-chloracctyl amino group (Knight, J.S.D.C., 1950, 66,37). Thus the wet-fastness of Azo Geranine... 

When dyeing with the molecularly-dispersed acid dyes most shades can be matched with a very limited number of colours such as ... 

The washing test applied to the first five was that of the I.S.O. (Mechanical Mild Wash at 40°C (104°F) for 30 minutes) and for the remainder the S.D.C. No. 2 test (50°C (122°F) for 45 minutes. The figures show that there is a loss of fastness of 1 to 2 gradings with the level-dyeing acid dyes, but none with the premetallized or fast acid dyes. Different unshrinkable finishes would not give exactly the same results but they could be expected to be of the same order. Shrink-resisting processes are usually applied to goods which are washed frequently, and it follows that the use of the molecularly-dispersed acid dyes is undesirable. 

When wash-fastness is not important the molecularly dispersed acid dyes can be used. The normal method of dyeing with acid and Glauber s salt gives a good reserve provided dyes are selected which are known to be suitable for the purpose. 

The molecularly dispersed acid dyes have poor wash-fastness and are not suitable for goods like men s socks which have usually had an unshrinkable treatment with the resultant adverse effect upon wet-fastness. 

Many of the molecularly dispersed acid dyes will give solid shades on wool and polyamide fibres. There is usually a tendency for the nylon 66 to... 

The basic dyes differ from all others because they are extracted quite easily by boiling with acetic acid or with alcohol. If, however, these reagents do not remove a substantial portion of the dye from the fibre, the next test is to boil the coloured material in dilute ammonia (1 ml of 0-88 ammonia per 100 ml of water) for 1 to 2 minutes in the presence of white cotton (Clayton, foe. cit.). If the solution is distinctly coloured and the cotton remains unstained, the presence of an acid dye is indicated. This can be confirmed by boiling with 40 per cent of Glauber s salt when a considerable proportion of molecularly-dispersed acid dyeS are stripped, but little effect is apparent with the fast acid dyes. If the cotton is stained the presence of... 

Use of acidic excipients. When a hydrophobic polymer with a physically dispersed acidic excipient is placed into an aqueous environment, water will diffuse into the polymer, dissolve the acidic excipient in the surface layers and the lowered pH will accelerate hydrolysis of the ortho ester bonds. 

Fig. 8. Schematic representation of water intrusion and erosion for one side of a bioerodible device containing dispersed acidic excipient [29]. Reprinted with permission...

At the same time, used Ni-Cd batteries require no different handling than that applicable to the new product. They simply do not present the unique risks that typify hazardous wastes they are not liquid, semi-liquid or easily dispersible, acidic or corrosive, or otherwise dangerous to touch. If spilled, they can be easily swept up. 

In the case of the 19-hour adsorption studies one might picture these thick films as consisting of a mixture of randomly dispersed acid or soap and solvent. However, if this were true, the rinsing treatments should have removed large amounts of the acid or soap along with the solvent. This was not the case. The fact that large amoimts of acid were not removed indicates that the acid is closely associated with the metal surface. 

Table 7 reports the surface free energy values and their dispersive, acidic, and basic components for polymers and other materials. There are some interesting features about the y" " (acidity) and the y (basicity) scales reported in this table ... 

Chem. Descrip. PEG-2 cocomethyi ammonium nitrate, iPA Uses Surfactant for cosmetics, agric., textiies, protective coatings, inks, pigment dispersions, acid pickiing baths, metaiworking, eiectropiating, piastics mfg. 

Uses Leveling agent for hair dyes coemulsifier and stabilizer for cosmetic emulsions neutralizer plasticizer antistat in acidic systems emulsifier for latex, dyes, and oils lubricant, softener, scouring agent, dye leveling agent and antistat for textiles in syn. latex paints dispersant acid cleaners process modifier in polymer industry raw material for quat. and amphoteric surfactants... 

Synonyms Methyl bis (2-hydroxyethyl) cocoalkyl quaternary ammonium nitrates PEG-2 cocomethyl ammonium nitrate Quaternary ammonium compds., cocoalkylbis (hydroxyethyl) methyl, nitrates Uses Surfactant for cosmetics, agric., textiles, protective coatings, inks, pigment dispersions, acid pickling baths, metalworking, electroplating, plastics Trade Name Synonyms Arquad C/12 Nitrate t[Akzo Nobel Surf. Chem. AB http //www.surface.aiaonobei.com]... 

Photoacid diffusion behavior in t-BOC-blocked chemically amplified positive DUV resists under various conditions was studied. Based on the experimental results, it was confirmed that only one mechanism dominated the acid diffusion in the resist film, and two diffusion paths, i.e., the remaining solvent in the resist film and hydrophilic OH sites of base phenolic resin, existed. Moreover, the effects of molecular weight dispersion, acid structure, and additional base component on both acid-diffusion behavior and lithographic performance were revealed. Finally, the acid diffusion behavior in the resist film was clarified and the acid diffusion length that affected the resist performance could be controlled. 

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