Water colors

Quality Specifications. Because of the extreme sensitivity of polyamide synthesis to impurities ia the iagredients (eg, for molecular-weight control, dye receptivity), adipic acid is one of the purest materials produced on a large scale. In addition to food-additive and polyamide specifications, other special requirements arise from the variety of other appHcations. Table 8 summarizes the more important specifications. Typical impurities iaclude monobasic acids arising from the air oxidation step ia synthesis, and lower dibasic acids and nitrogenous materials from the nitric acid oxidation step. Trace metals, water, color, and oils round out the usual specification Hsts. 

Inks. The main components of the inks ate typically water, colorants, and humectants. Additives ate used to control drying time, waterfastness, lightfastness, and consistency of drop formation. Water is an excellent vehicle for ink jet because of its high surface tension and safety in all environments. 

Starch pyrodextrins and British gums have the abiUty, in aqueous dispersion, to form films capable of bonding like or unlike materials. Thus, they have uses as adhesives for envelopes, postage stamps, and other products. These dextrins are used in glass-fiber siting to protect the extmded fiber from abrasion, and as binders for metal core castings, water color paints, briquettes, and many other composite materials (qv). 

Color can be removed effectively and economically with either alum or ferric sulfate at pH values of 5—6 and 3—4, respectively. The reaction is stoichiometric and is a specific reaction of the coagulant with the color to form an insoluble compound (17). The dosage required may be as high as 100—150 mg/L (380—570 mg/gal). Raw-water colors may be as high as 450—500 units on the APHA color scale. The secondary MCL (maximum contaminant level) for color in the finished water is 15 units, although most municipal treatment plants produce water that seldom exceeds 5 units. 

A final are we should discuss is color removal. This is perhaps the most difficult impurity to remove from waters. In surface waters color is associated with dissolved or colloidal suspensions of decayed vegetation and other colloidal suspensions. The composition of this material is largely tannins and lignins, the components that hold together the cellulose cells in vegetation. In addition to their undesirable appearance in drinking water, these organics can cause serious problems in downstream water purification processes. For examples ... 

Kaltwasser-bad. n. cold-water bath, -farbe,/. cold-water color or paint, -probe, /. cold-water test. -Strom, m. stream or current of cold water. 

Tuschen, n. painting with India ink painting with water colors. 

Tuschfarbe, /. water color, tuschieren, v.t. paint with India ink or water color ink in touch, tut, pr. S sing, (of tun) does, makes, etc. 

Wasser-entzieher, m, (Textiles, etc.) hydroextractor. -entziehung, /, removal of water, dehydration desiccation hydroextraction, -entziehungsmittel, n, dehydrating agent, -erguss, m, watery effusion, edema, -farbe, /, water color color of water, -foss, n. water cask, water tub. -fenchel, m. water fennel. 

WasserUnie, /, water line. wasser-Ios, a. waterless, without water, anhydrous, -loslich, a. water-soluble, Wasser-luftpumpe, /, water vacuum pump, -maische, /. (aqueous) infusion mash, -malerei, /, water-color painting, -mangel, m, lack (or scarcity) of water, -mantel, m. water jacket, -mass, n, water gage, -menge, /, amount of water,... 

Areas of application include wood coloration [45], paper mass coloration [46] and paper surface coating in the lime press [47], the office articles and artists colors sector pigments are used in colored pencils, crayons, and writing and pastel chalks or in water colors, as well as in cosmetics, especially soap [48],... 

Besides its use in cast resin, such as methylmethacrylate mixtures, P.Y.16 has gained recognition as a colorant for felt-tip pens, water colors, and a number of related applications. It lends color to leather, mass and surface paper coloration, and paper pulp. 

Moreover, P.Br.25 is used in a variety of specialty media, for instance in oil colors for artists and in water colors. It lends itself to solvent-based wood stains. The products are very lightfast (step 7) and fast to overcoating. 

Incorporated in plasticized PVC, P.B.15, like other phthalocyanine pigments, is usually entirely fast to migration. Moreover, it provides excellent lightfastness. P.B.15 also finds use in various types of PUR foam materials as well as in rubber. Its redder and frequently cleaner shade compared to corresponding stabilized types makes it an equally useful pigment for other media. This applies especially for water-based systems. Textile printing, paper mass coloration, paper surface treatment, and paper pulp are areas of application as suitable for the use of P.B.15 as office articles, including colored pencils, blackboard chalks for schools, and water colors. 

P.B.15 3, like stabilized a-Copper Phthalocyanine Blue, markedly affects the hardening of unsaturated polyester cast resins. The list of applications also includes PUR foam materials, office articles, such as colored pencils, wax crayons, and water colors, as well as spin dyeing of polypropylene, polyacrylonitrile, secondary acetate, polyamide, polyester, and viscose. Used in polyester spin dyeing, P.B.15 3 satisfies the thermal requirements of the condensation process (Sec. 1.8.3.8). 1/3 and 1/25 SD samples equal step 7-8 on the Blue Scale for lightfastness. Textile fastnesses, such as stability to wet and dry crocking are perfect. 

There are a number of other media which are also pigmented with P.V.23. The list includes office articles and artists colors, such as drawing inks and fiber-tip pen inks, wax crayons, oil paints, and high quality water colors, water- or solvent-based pigmented wood stains, cleaning agents, and mass colored paper. 

Nickel phosphate is used in coating steel and in treatment of metal surfaces. It also is used to prepare the pigment, nickel yellow for oil and water colors. The compound is used in electroplating also. 

Iii—Encre, French Tlnte, German Atramentum, Latin.—Inlt, according to the purposes For which it is intended, is found in different forms. Writing ink, which is of various colors, is liquid, and may be either a clear fluid, as ordinary red ink, or may consist of a finely-divjded precipitate equally diffused through the menstruum, as in common black ink. Printing ink is likewise of divers hues, but has a pasty consistence. The form of ink known as Indian, which is employed more especially as a water-color, is in solid cakes. 

Another important discovery by Cavendish is based upon an observation of Priestley. Priestley had experimented by passing the electric spark through air confined over water colored with litmus, and found that the air was diminished in volume and that the litmus was reddened. As Priestley believed that electricity was another form of phlogiston, his results were puzzling to him. His curiosity excited by Priestley s observations, Cavendish also attacked the problem. This resulted in his proof that, by this means, practically all the phlogisticated air could by a sufficient... 

What is the main difference between the structure of oil paints and that of water colors ... 

In oil paints, a pigment is combined with oil, and in water color a pigment is combined with gum arabic. 

Humic DOC only, derived from water color measurements. 

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