Polyester fiber dyeing

Dyes polyester fibers fast blue, brown, and red shades... 

Standard polyester fibers contain no reactive dye sites. PET fibers are typically dyed by diffusiag dispersed dyestuffs iato the amorphous regions ia the fibers. Copolyesters from a variety of copolymeri2able glycol or diacid comonomers open the fiber stmcture to achieve deep dyeabiHty (7,28—30). This approach is useful when the attendant effects on the copolyester thermal or physical properties are not of concern (31,32). The addition of anionic sites to polyester usiag sodium dimethyl 5-sulfoisophthalate [3965-55-7] has been practiced to make fibers receptive to cationic dyes (33). Yams and fabrics made from mixtures of disperse and cationicaHy dyeable PET show a visual range from subde heather tones to striking contrasts (see Dyes, application and evaluation). 

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. 

This mixture is known as Quinoline Yellow A [8003-22-3] (Cl 47000) and is most widely used with polyester fibers (109). Upon sulfonation, the water-soluble Quinoline Yellow S or Acid Yellow 3 [8004-92-0] (Cl 47005) is obtained. This dye is used with wool and its aluminum salt as a pigment. Foron Yellow SE-3GL (Cl Disperse Yellow 64) is the 3-hydroxy-4-bromo derivative. Several other quinoline dyes are commercially available and find apphcations as biological stains and analytical reagents (110). 

Blends of polyester with cotton (qv) or viscose are first dyed with disperse dyes, then with sulfur dyes (see Fibers, polyester Fibers, regenerated CELLULOSics). Disperse and sulfur dyes can also be appHed simultaneously in a pad—dry—thermofix/chemical reduction pad—steam sequence. In this case, the sulfur dyes cannot be used in thein reduced form because of the effect of the sodium sulfide on the disperse dye. Therefore, this method is confined to the solubilized sulfur dyes or sulfur dyes in the dispersed form. 

Application Techniques, Structural Variations, and Fastness Properties. When appHed to polyester fiber, many of the disperse dyes originally developed for ceUulose acetate were found to be deficient in Hghtfastness, build-up properties, and especially fastness to the high temperatures employed in the newer dyeing and finishing, printing, and Thermosol (dry heat) processes. 

Dye caiiieis aie needed foi complete dye penetration of polyester fibers. Carriers cause the glass-transition temperature, of the polyester polymer to become lower and allow the penetration of water-insoluble dyes into the fiber. 

M. C. Keen and R. J. Thomas, "Absorption Properties of Latyl Disperse Dyes on AppHcation to Dacron Polyester Fibers," Eyes and Chemicals Technical Bulletin, E. I. du Pont de Nemours Co., Inc., Organic Chemicals Dept., Wilmington, Del., 1992. 

The appearance of synthetic fibers in the 1920s accelerated the further development of anthraquinone dyes. Soon after British Celanese succeeded in commerciali2ing cellulose acetate fiber in 1921, anthraquinone disperse dyes for this fiber were invented by Stepherdson (British Dyestuffs Corp.) and Celatenes (Scottish Dyes) independendy. Anthraquinone disperse dyes for polyester fiber were developed after the introduction of this fiber by ICI and Du Pont in 1952. These dyes were improved products of the disperse dyes that had been developed for cellulose acetate fiber 30 years before. 

In 1923, the first disperse dye was developed for dyeing cellulose acetate fibers. However, in recent years the most important appHcation of disperse dyes has been to dye polyester fibers. Accompanied by the rapid growth of polyester fibers after World War II, disperse dyes have currendy achieved the largest production among all dye classes in terms of quantity (106). 

Cl Disperse Blue 56 is the most important blue dye for polyester fibers because it has a brilliant shade, excellent lightfastness, and good leveling properties. 

Polyester fibers are based on poly(ethylene terephthalate) (PET) some modified versions are formed by copolymerization, eg, basic dyeable polyester. The modified forms dye in analogous manner to other fibers of similar charge. 

Dyeing Mechanism. Unmodified polyester fibers are very hydrophobic and absorb only minimal amounts of water and are therefore only dyeable with hydrophobic disperse dyes. The mechanism of dyeing is by simple partition, the so-called soHd solution mechanism. The dyeing process can be described by the general scheme... 

Wool—Polyester Fibers. The 45/55 wool—polyester blend is the most common fiber combination in the worsted industry. Strength and exceUent dimensional stabiHty of the polyester fiber enable the creation of lightweight wear fabrics not obtainable before. Economy has modified the fiber ratio and 30/70 and 20/80 wool—polyester blends are as common as the classical 45/55 blend. Disperse dyes for polyester and acid or neutral premetaUized dyes for wool are employed in a one-bath process. Should cationic dyes be used for the wool portion, a one-bath procedure can only be employed for light to medium shades, whereas dark shades require a one-bath two-step process. Wool blends should not be dyed above 105°C in order to avoid deterioration of the fiber quaHty. 

Polyester Fiber Blends. Disperse dyeable and cationic dyeable polyester fibers are frequentiy combiaed ia apparel fabrics for styling purposes. Whereas the disperse dyes dye both fibers, but ia differeat depths, selected cationic dyes reserve the disperse dyeable fiber completely, resulting ia color/white effects. 

Polyester Fiber—Nylon Blends. This fiber blead is used ia apparel fabrics as weU as ia carpets. Disperse dyes dye both fibers, however they... 

Polyester Fibei Acrylic Fiber Blends. This fiber blend is dyed ia a similar fashion to that of the blends of the different polyester fibers. The selection of cationic dyes is substantially larger for the acryhc blend. 

Basic (Cationic) Dyes. The use of basic dyes is confined mainly to acryUc textile fibers, acetate, and as complementary dyes for acid-modified polyester fibers that accept this class of dyes. 

Disperse—Vat Combinations. These require a two-step fixation. The disperse dye is fixed first, usually by dry heat, followed by impregnating of the textile with an alkaU and reducing agent solution and short steam fixation for the vat dye. The selected disperse dyes fixed in the polyester fiber are not destroyed by the reducing agent, but disperse dye remaining on the cellulose is destroyed. 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

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